Pigment dispersion syndrome and pigmentary glaucoma after secondary sulcus transscleral fixation of single-piece foldable posterior chamber intraocular lenses in Chinese aphakic patients.

Science.gov (United States)

Tong, Nianting; Liu, Fuling; Zhang, Ting; Wang, Liangyu; Zhou, Zhanyu; Gong, Huimin; Yuan, Fuxiang

2017-05-01

To describe secondary pigment dispersion syndrome (PDS) and pigmentary glaucoma after secondary sulcus transscleral fixation of 1-piece hydrophobic acrylic foldable posterior chamber intraocular lenses (PC IOLs) in aphakic patients in a Chinese population. Department of Ophthalmology, Qingdao Municipal Hospital, Qingdao, China. Retrospective case series. This chart review included eyes that had secondary sulcus transscleral fixation of a 1-piece hydrophobic acrylic foldable PC IOL (Tecnis ZCB00) between March 2011 and March 2014. The patients' demographic data, clinical data, postoperative complications, intervals between initial surgery and the onset of PDS, pigmentary glaucoma occurrences, and findings on slitlamp biomicroscopy, gonioscopy, and ultrasound biomicroscopy (UBM) were recorded. The study comprised 23 consecutive eyes of 21 patients. Seventeen eyes of 16 patients were diagnosed with PDS, and 7 eyes of 6 patients were diagnosed with pigmentary glaucoma. The slitlamp examination and UBM showed that the location between the IOL optic and the posterior surface of the iris was very close. Slitlamp examination of the anterior chamber angle using a gonioscope showed dense pigment deposition on the IOL surfaces. A reverse pupillary block was found in 10 eyes of 9 patients. Other postoperative complications included intraocular hemorrhage, pupillary capture of the IOL optic, IOL tilt, IOL decentration, IOL dislocation, and suture erosion. The 1-piece hydrophobic acrylic foldable PC IOL was not suitable for sulcus transscleral fixation because of a high incidence of PDS and pigmentary glaucoma after surgery in a Chinese population. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

UV laser ablation of intraocular lenses: SEM and AFM microscopy examination of the biomaterial surface

International Nuclear Information System (INIS)

Spyratou, E.; Asproudis, I.; Tsoutsi, D.; Bacharis, C.; Moutsouris, K.; Makropoulou, M.; Serafetinides, A.A.

2010-01-01

Several new materials and patterns are studied for the formation and etching of intraocular lenses (IOLs), in order to improve their optical properties, to reduce the diffractive aberrations and to decrease the incidence of posterior capsular opacification. The aim of this study is to investigate the use of UV (λ = 266 nm) laser pulses to ablate the intraocular lenses materials, and thus to provide an alternative to conventional surface shaping techniques for IOLs fabrication. Ablation experiments were conducted using various polymer substrates of hydrophobic acrylic IOLs and PMMA IOLs. We investigated the ablation efficiency and the morphology of the ablated area by imaging the surface modification with atomic force microscopy (AFM) and scanning electron microscopy (SEM). The morphological appearance of IOL samples reveals the effect of a photochemical and photothermal ablation mechanism.

UV laser ablation of intraocular lenses: SEM and AFM microscopy examination of the biomaterial surface

Energy Technology Data Exchange (ETDEWEB)

Spyratou, E., E-mail: ellas5@central.ntua.gr [National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Physics, Zografou Campus, Athens, 15780 (Greece); Asproudis, I. [Department of Ophthalmology, University Hospital of Ioannina, Ioannina, 45110 (Greece); Tsoutsi, D. [Department of Chemistry, University of Ioannina, Ioannina, 45110 (Greece); Bacharis, C.; Moutsouris, K.; Makropoulou, M.; Serafetinides, A.A. [National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Physics, Zografou Campus, Athens, 15780 (Greece)

2010-02-01

Several new materials and patterns are studied for the formation and etching of intraocular lenses (IOLs), in order to improve their optical properties, to reduce the diffractive aberrations and to decrease the incidence of posterior capsular opacification. The aim of this study is to investigate the use of UV ({lambda} = 266 nm) laser pulses to ablate the intraocular lenses materials, and thus to provide an alternative to conventional surface shaping techniques for IOLs fabrication. Ablation experiments were conducted using various polymer substrates of hydrophobic acrylic IOLs and PMMA IOLs. We investigated the ablation efficiency and the morphology of the ablated area by imaging the surface modification with atomic force microscopy (AFM) and scanning electron microscopy (SEM). The morphological appearance of IOL samples reveals the effect of a photochemical and photothermal ablation mechanism.

Refractive Results: Safety and Efficacy of Secondary Piggyback Sensar™ AR40 Intraocular Lens Implantation to Correct Pseudophakic Refractive Error

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Alahmady Hamad Alsmman Hassan

2016-01-01

Full Text Available In this study we evaluate the visual outcomes, safety, efficacy, and stability of implanting of second sulcus intraocular lens (IOL to correct unsatisfied ametropic patients after phacoemulsification. Methods. Retrospective study of 15 eyes (15 patients underwent secondary intraocular lens implanted into the ciliary sulcus. The IOL used was a Sensar IOL three-piece foldable hydrophobic acrylic IOL. The first IOL in all patients was acrylic intrabagal IOL implanted in uncomplicated phacoemulsification surgery. Results. Fifteen eyes (15 patients were involved in this study. Preoperatively, mean log⁡MAR UDVA and CDVA were 0.88 ± 0.22 and 0.19 ± 0.13, respectively, with a mean follow-up of 28 months (range: 24 to 36 months. At the end of the follow-up, all eyes achieved log⁡MAR UDVA of 0.20 ± 0.12 with postoperative refraction ranging from 0.00 to −0.50 D of attempted emmetropia. Conclusions. Implantation of the second sulcus SensarAR40 IOL was found to be safe, easy, and simple technique for management of ametropia following uncomplicated phacoemulsification.

Corneal edema and permanent blue discoloration of a silicone intraocular lens by methylene blue.

Science.gov (United States)

Stevens, Scott; Werner, Liliana; Mamalis, Nick

2007-01-01

To report a silicone intraocular lens (IOL) stained blue by inadvertent intraoperative use of methylene blue instead of trypan blue and the results of experimental staining of various lens materials with different concentrations of the same dye. A "blue dye" was used to enhance visualization during capsulorhexis in a patient undergoing phacoemulsification with implantation of a three-piece silicone lens. Postoperatively, the patient presented with corneal edema and a discolored IOL. Various IOL materials were experimentally stained using methylene blue. Sixteen lenses (4 silicone, 4 hydrophobic acrylic, 4 hydrophilic acrylic, and 4 polymethylmethacrylate) were immersed in 0.5 mL of methylene blue at concentrations of 1%, 0.1%, 0.01%, and 0.001%. These lenses were grossly and microscopically evaluated for discoloration 6 and 24 hours after immersion. The corneal edema resolved within 1 month after the initial surgical procedure. After explantation, gross and microscopic analyses of the explanted silicone lens revealed that its surface and internal substance had been permanently stained blue. In the experimental study, all of the lenses except the polymethylmethacrylate lenses were permanently stained by methylene blue. The hydrophilic acrylic lenses showed the most intense blue staining in all dye concentrations. This is the first clinicopathological report of IOL discoloration due to intraocular use of methylene blue. This and other tissue dyes may be commonly found among surgical supplies in the operating room and due diligence is necessary to avoid mistaking these dyes for those commonly used during ocular surgery.

Intraocular Lens Calcification; a Clinicopathologic Report

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Mozhgan Rezaei-Kanavi

2009-04-01

Full Text Available

PURPOSE: To describe the clinical and pathological features of a case of hydrogel intraocular lens (IOL calcification. CASE REPORT: A 48-year-old man underwent explantation of a single-piece hydrophilic acrylic intraocular lens in his left eye because of decreased visual acuity and milky white opalescence of the IOL. The opacified lens was exchanged uneventfully with a hydrophobic acrylic IOL. Gross examination of the explanted IOL disclosed opacification of the optic and haptics. Full-thickness sections of the lens optic were stained with hematoxylin and eosin (H&E, von Kossa and Gram Tworts'. Microscopic examination of the sections revealed fine and diffuse basophilic granular deposits of variable size within the lens optic parallel to the lens curvature but separated from the surface by a moderately clear zone. The deposits were of high calcium content as evident by dark brown staining with von Kossa. Gram Tworts' staining disclosed no microorganisms. CONCLUSION: This report further contributes to the existing literature on hydrogel IOL calcification.

Prótese intra-ocular de resina acrílica em cães e gatos Acrylic resin intraocular prosthesis in dogs and cats

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S.C. Rahal

2000-08-01

Full Text Available Foram atendidos no Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Unesp - Campus de Botucatu, 11 animais (oito cães e três gatos, com alterações oftálmicas unilaterais graves que levaram à perda total da função ocular (protrusão de globo com injúria nervosa e estrutural, perfurações de córnea com perda de conteúdo intra-ocular e endoftalmites, entre outras. Os animais, com idades entre dois meses e 10 anos, foram submetidos à evisceração e posterior inclusão de esfera de resina acrílica (metilmetacrilato na capa córneo-escleral ou escleral. As esferas foram previamente confeccionadas e esterilizadas por autoclavagem. No pós-operatório foram utilizados antiinflamatórios e antibioticoterapia tópica combinada ou não a sistêmica. O período de observação variou de 2 meses a 3 anos e os aspectos avaliados foram secreção ocular, blefarospasmo, sinais de desconforto e estética. Obtiveram-se resultados satisfatórios em oito casos. Concluiu-se que a resina acrílica pode ser uma alternativa para uso como inclusão em cavidade anoftálmica.Eleven animals (eight dogs and three cats, aged between two months and ten years were referred to the Veterinary Hospital of Faculty of Veterinary Medicine and Animal Science - Unesp, Botucatu, Brazil. These animals presented severe unilateral ophthalmic changes that lead to a total loss of ocular function, such as prolapsed eyes with nervous and structural injury, corneal damage with loss of intraocular contents or endophthalmitis among others. They were submitted to evisceration followed by the insertion of an acrylic resin prosthesis (methylmethacrylate in the corneoscleral or scleral shell. The spheres were previously made and sterilized by autoclave. The postoperative medical therapy included topical and systemic broad-spectrum antibiotics for seven days and anti-inflammatory drugs. The follow-up time varied from two months to three years. The evaluated

Microscopic analysis of an opacified OFT CRYL® hydrophilic acrylic intraocular lens

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Bruna Vieira Ventura

Full Text Available ABSTRACT A 51-year-old patient underwent posterior vitrectomy with perfluoropropane gas injection, phacoemulsification, and implantation of an Oft Cryl® hydrophilic acrylic intraocular lens (IOL because of traumatic retinal detachment and cataract in the right eye. On the first postoperative day, gas was filling the anterior chamber because of patient's non-compliance in terms of head positioning, and was reabsorbed within one week. Eight months later, the patient returned complaining of a significant decrease in vision. IOL opacification was noticed by slit-lamp examination. The lens was explanted to undergo gross and light microscopic analysis. The lens was also stained with the alizarin red method for calcium identification. Light microscopic analysis confirmed the presence of granular deposits, densely distributed in an overall circular pattern in the central part of the lens optic. The granules stained positive for calcium. This is the first case of the opacification of this type of hydrophilic lens. Surgeons should be aware of this potential postoperative complication, and the use of hydrophilic IOLs should be avoided in procedures involving intracameral gas because of the risk of IOL opacification.

Polyurethane-acrylate-based hydrophobic film: Facile fabrication, characterization, and application

Science.gov (United States)

Park, Jongsung; Nguyen, Bui Quoc Huy; Kim, Ji-Kwan; Shanmugasundaram, Arunkumar; Lee, Dong-Weon

2018-06-01

Polyurethane-acrylate (PUA) is a versatile UV-curable polymer with a short curing time at room temperature, whose surface structure can be flexibly modified by applying various micropatterns. In this paper, we propose a facile and cost-effective fabrication method for the continuous production of an optically transparent PUA-based superhydrophobic thin film. Poly(dimethylsiloxane) (PDMS) was employed as a soft mold for the fabrication of PUA films through the roll-to-roll technique. In addition, nanosilica was spray-coated onto the PUA surface to further improve the hydrophobicity. The fabricated PUA thin film showed the highest static water contact angle (WCA) of ∼140°. The high durability of the PUA film was also demonstrated through mechanical impacting tests. Furthermore, only ∼2% of voltage loss was observed in the solar panel covered with the PUA-based superhydrophobic film. These obtained results indicate the feasibility of applying the film as a protective layer in applications requiring a high transparency and a self-cleaning effect.

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

Science.gov (United States)

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

2015-05-01

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

Intraocular lenses and clinical treatment in paediatric cataract

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Camila Ribeiro Koch Pena

2015-06-01

Full Text Available Pediatric cataract is the most common treatable cause of blindness in children. Prevalence, etiology and morphology vary with the socioeconomic development. The treatment goal is to reduce amblyopia, being difficult management especially in unilateral cases. The decision on aphakia or primary intraocular lens should be individualized as well as correction with contact lens or spectacles. The intraocular lens single-piece hydrophobic acrylic are the most implanted in children and the preferably is in the capsular bag. The Sanders-Retzlaff-Kraff theoretic (SRK/T stressing that is described as more predictable, following Holladay I and SRK II and the recommendation is to under correction +6.0 or +8.0 dioptrias expecting the growth of the eye. The posterior capsule opacity is the most frequent complication and varies with the material choice of the lens. Glaucoma is the most serious postoperative complication and depends on the timing of the surgery, primary lens implantation and time of post surgical follow-up. The adherence to occlusion therapy with patching is critical to the visual prognosis and is determined by the child’s age and laterality of the cataract. There was significant improvement in the surgery and in IOLs, however the final visual prognosis is still not desirable.

Effects of content and surface hydrophobic modification of BaTiO3 on the cooling properties of ASA (acrylonitrile-styrene-acrylate copolymer)

Science.gov (United States)

Xiang, Bo; Zhang, Jun

2018-01-01

For the field of cool material, barium titanate (BaTiO3, BT) is still a new member that needs to be further studied. Herein, the effects of both content and surface hydrophobic modification of BT on the cooling properties of acrylonitrile-styrene-acrylate copolymer (ASA) were detailedly investigated, aiming to fabricate composited cool material. Butyl acrylate (BA) was employed to convert the surface of BT from hydrophilic to hydrophobic. The addition of unmodified BT could significantly improve the solar reflectance of ASA, especially when the addition amount is 3 vol%, the near infrared (NIR) reflectance increased from 22.02 to 72.60%. However, serious agglomeration occurred when the addition amount increased to 5 vol% and therefore led to a relatively smaller increase in solar reflectance and an obvious decline in impact strength. After surface hydrophobic modification, the modified BT (M-BT) presented better dispersibility in ASA matrix, which contributed to the improvement of both solar reflectance and impact strength. In addition, the temperature test provided a more sufficient and intuitive way to evaluate the cooling effect of the composited cool materials, and a significant decrease (over 10 °C) could be achieved in the temperature test when M-BT particles were introduced.

Poly (ethylene oxide)-block-poly (n-butyl acrylate)-blockpoly (acrylic acid) triblock terpolymers with highly asymmetric hydrophilic blocks: synthesis and aqueous solution properties

OpenAIRE

Petrov, P. (Petar); Yoncheva, K. (Krassimira); Mokreva, P. (Pavlina); Konstantinov, S. (Spiro); Irache, J.M. (Juan Manuel); Müller, A.H.E. (Axel H.E.)

2013-01-01

The synthesis and aggregation behaviour in aqueous media of novel amphiphilic poly(ethylene oxide)- block-poly(n-butyl acrylate)-block-poly(acrylic acid) (PEO–PnBA–PAA) triblock terpolymers were studied. Terpolymers composed of two highly asymmetric hydrophilic PEO (113 monomer units) and PAA (10–17 units) blocks, and a longer soft hydrophobic PnBA block (163 or 223 units) were synthesized by atom transfer radical polymerisation (ATRP) of n-butyl acrylate and tert-butyl acrylate ...

Incidência de opacificação de cápsula posterior em pacientes submetidos à facoemulsificação e implante de lentes intra-oculares acrílicas hidrofílicas expansíveis Incidence of posterior capsule opacification in patients submitted to phacoemulsification and expandable acrylic intraocular lens implantation

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Hilton Arcoverde Gonçalves de Medeiros

2006-06-01

Full Text Available OBJETIVO: Avaliar prospectivamente os resultados das lentes intra-oculares de polímeros expansíveis implantadas em pacientes submetidos à facoemulsificação, quanto à incidência de opacificação de cápsula posterior, levando em consideração a biocompatibilidade das lentes expansíveis. MÉTODOS: O grupo de estudo foi composto por 830 pacientes, 1.200 olhos, que foram submetidos a facoemulsificação, utilizando a mesma técnica, variando-se apenas o diâmetro da capsulorrexe, pelo mesmo cirurgião, no período de 1998 a 2002, com implante de lente intra-ocular hidrofílica expansível. O acompanhamento médio foi de 2,4 anos, variando de seis meses a quatro anos. RESULTADOS: O número total de opacificação de cápsula posterior foi de 54 casos. CONCLUSÃO: A incidência de opacificação de cápsula posterior encontrada no grupo foi de 4,6%.PURPOSE: To evaluate prospectively the results of expandable acrylic intraocular lenses in patients submitted to phacoemulsification as regard posterior capsule opacification. METHODS: The study group consisted of 830 patients, 1,200 eyes that underwent phacoemulsification from 1998 to 2002, by the same surgeon, using the same technique but with different diameters of capsulorrhexis, with expandable hydrophilic acrylic intraocular lens implantation. The mean follow-up was 2.4 years, ranging from 6 months to 4 years. RESULTS: The total number of posterior capsule opacification was 54 cases. CONCLUSIONS: The incidence of posterior capsule opacification was 4.6% in these patients.

Dynamically formed hydrous zirconium (IV) oxide-polyelectrolyte membranes. III: Poly(acrylic acid) and substituted poly(acrylic acid) homo, co and terpolymer membranes

International Nuclear Information System (INIS)

Van Reenen, A.J.; Sanderson, R.D.

1989-01-01

A series of acrylic acid and substituted acrylic acid homo, co and terpolymers was synthesised. These polymers were used as polyelectrolytes in dynamically formed hydrous zirconium (iv) oxide-polyelectrolyte membranes. Substitution of the acrylic acid α-hydrogen was done to increase the number of carboxylic acid groups per monomer unit and to change the acid strength of acrylic acid carboxylic acid group. None of these changes improved the salt rejection of these membranes over that of commercially used poly(acrylic acid). Improvement in rejection was found when a hydrophobic comonomer, vinyl acetate, was used in conjunction with acrylic acid in a copolymer dynamic membrane. 16 refs., 6 figs., 1 tab

The use of dielectric spectroscopy for the characterisation of the precipitation of hydrophobically modified poly(acrylic-acid) with divalent barium ions

DEFF Research Database (Denmark)

Christensen, Peter Vittrup; Keiding, Kristian

2009-01-01

The use of dielectric spectroscopy as a monitor for coagulation processes was investigated. Hydrophobically modified poly(acrylic-acid) polymers were used as model macromolecules and coagulated with barium ions. The coagulation process was quantified using a photometric dispersion analyser, thereby...... serving as a point of reference for the dielectric spectroscopy. It was found that the hydrophobic modification increased the dosage of barium needed to obtain complete coagulation, whereas the dosage required to initiate coagulation was lowered. The coagulation of the polymer samples caused...... the relaxation time of the measured dielectric dispersion to increase, and this parameter was found to be a good indicator of the formation of polymer aggregates. The magnitude of the dielectric dispersion decreased as a function of barium dosage, but when coagulation was initiated an increase was observed...

Hydrophobic surface modification of TiO2 nanoparticles for production of acrylonitrile-styrene-acrylate terpolymer/TiO2 composited cool materials

Science.gov (United States)

Qi, Yanli; Xiang, Bo; Tan, Wubin; Zhang, Jun

2017-10-01

Hydrophobic surface modification of TiO2 was conducted for production of acrylonitrile-styrene-acrylate (ASA) terpolymer/titanium dioxide (TiO2) composited cool materials. Different amount of 3-methacryloxypropyl-trimethoxysilane (MPS) was employed to change hydrophilic surface of TiO2 into hydrophobic surface. The hydrophobic organosilane chains were successfully grafted onto TiO2 through Sisbnd Osbnd Ti bonds, which were verified by Fourier transformed infrared spectra and X-ray photoelectron spectroscopy. The water contact angle of the sample added with TiO2 modified by 5 wt% MPS increased from 86° to 113°. Besides, all the ASA/TiO2 composites showed significant improvement in both solar reflectance and cooling property. The reflectance of the composites throughout the near infrared (NIR) region and the whole solar wavelength is increased by 113.92% and 43.35% compared with pristine ASA resin. Simultaneously, significant drop in temperature demonstrates excellent cooling property. A maximum decrease approach to 27 °C was observed in indoor temperature test, while a decrease around 9 °C tested outdoors is achieved.

[Comparison of surface light scattering of acrylic intraocular lenses made by lathe-cutting and cast-molding methods--long-term observation and experimental study].

Science.gov (United States)

Nishihara, Hitoshi; Ayaki, Masahiko; Watanabe, Tomiko; Ohnishi, Takeo; Kageyama, Toshiyuki; Yaguchi, Shigeo

2004-03-01

To compare the long-term clinical and experimental results of soft acrylic intraocular lenses(IOLs) manufactured by the lathe-cut(LC) method and by the cast-molding(CM) method. This was a retrospective study of 20 patients(22 eyes) who were examined in a 5- and 7-year follow-up study. Sixteen eyes were implanted with polyacrylic IOLs manufactured by the LC method and 6 eyes were implanted with polyacrylic IOLs manufactured by the CM method. Postoperative measurements included best corrected visual acuity, contrast sensitivity, biomicroscopic examination, and Scheimpflug slit-lamp images to evaluate surface light scattering. Scanning electron microscopy and three-dimensional surface analysis were conducted. At 7 years, the mean visual acuity was 1.08 +/- 0.24 (mean +/- standard deviation) in the LC group and 1.22 +/- 0.27 in the CM group. Surface light-seatter was 12.0 +/- 4.0 computer compatible tapes(CCT) in the LC group and 37.4 +/- 5.4 CCT in the CM group. Mean surface roughness was 0.70 +/- 0.07 nm in the LC group and 6.16 +/- 0.97 nm in the CM group. Acrylic IOLs manufactured by the LC method are more stable in long-termuse.

Results of intraocular lens implantation with capsular tension ring in subluxated crystalline or cataractous lenses in children.

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Das, Pranab; Ram, Jagat; Brar, Gagandeep Singh; Dogra, Mangat R

2009-01-01

To evaluate the outcome of intraocular lens (IOL) implantation using capsular tension ring (CTR) in subluxated crystalline or cataractous lenses in children. Tertiary care setting. We prospectively studied 18 eyes of 15 children with subluxation of crystalline or cataractous lenses between 90 degrees up to 210 degrees after phacoemulsification, CTR and IOL implantation. Each child was examined for IOL centration, zonular dehiscence and posterior capsular opacification (PCO). Age of the patient ranged between five to 15 years. Out of 18 eyes, seven had traumatic and 11 had spontaneous subluxation of crystalline or cataractous lens. Phacoemulsification was successfully performed with CTR implantation in the capsular bag. Intraoperative zonular dialysis occurred in two eyes. Anterior vitrectomy was performed in six eyes to manage vitreous prolapse. IOL implanted was polymethyl methacrylate (PMMA) in eight eyes, hydrophobic acrylic in seven and hydrophilic acrylic in three. Follow-up ranged from 24 months to 72 months. Sixteen eyes had a best corrected visual acuity of 20/40 or better. Nine eyes developed significant PCO and were managed with Neodymium Yttrium Aluminum Garnet (Nd:YAG) laser posterior capsulotomy. One eye with acrylic IOL in the capsular bag had IOL dislocation after two years which was managed with vitrectomy and secondary trans-scleral fixation of IOL. Phacoaspiration with CTR implantation makes capsular bag IOL fixation possible in most of the eyes with subluxated crystalline or cataractous lenses. PCO still remains a challenge in children with successful phacoaspiration with CTR implantation.

Small-incision 4-point scleral suture fixation of a foldable hydrophilic acrylic intraocular lens in the absence of capsule support.

Science.gov (United States)

Terveen, Daniel C; Fram, Nicole R; Ayres, Brandon; Berdahl, John P

2016-02-01

To determine the visual outcomes and complications of a new small-incision technique for 4-point fixation of a hydrophilic acrylic posterior chamber intraocular lens (IOL) in the absence of capsule support. Three North American tertiary referral centers and a private practice. Retrospective case series. Secondary IOL placement was performed from 2011 to 2014. Indications for surgery, clinical results, and complications were analyzed. Primary outcomes included postoperative corrected distance visual acuity (CDVA) and surgical complications. Charts of 35 patients (37 eyes) were reviewed. The mean age at surgery was 56 years, and the mean follow-up was 6 months (range 3 to 24 months). Clinical indications included a dislocated IOL (30%), ocular trauma (19%), crystalline lens subluxation (19%), uveitis-glaucoma-hyphema syndrome (5%), post-complicated cataract (8%), congenital cataract (8%), and decompensated cornea (3%). The mean CDVA improved from 20/80 preoperatively to 20/40 postoperatively (P IOL dislocation (3%). Small-incision 4-point scleral fixation of the Akreos AO60 hydrophilic acrylic IOL in the absence of capsule support appears to be a safe and effective technique for secondary IOL placement. Drs. Berdahl and Ayres are consultants to Bausch & Lomb, Inc. Drs. Ayres and Fram have received speaker fees from Bausch & Lomb. Dr. Terveen does not have a financial or proprietary interest in any material or methods mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

In vivo subjective and objective longitudinal chromatic aberration after bilateral implantation of the same design of hydrophobic and hydrophilic intraocular lenses.

Science.gov (United States)

Vinas, Maria; Dorronsoro, Carlos; Garzón, Nuria; Poyales, Francisco; Marcos, Susana

2015-10-01

To measure the longitudinal chromatic aberration in vivo using psychophysical and wavefront-sensing methods in patients with bilateral implantation of monofocal intraocular lenses (IOLs) of similar aspheric design but different materials (hydrophobic Podeye and hydrophilic Poday). Instituto de Optica, Consejo Superior de Investigaciones Cientificas, Madrid, Spain. Prospective observational study. Measurements were performed with the use of psychophysical (480 to 700 nm) and wavefront-sensing (480 to 950 nm) methods using a custom-developed adaptive optics system. Chromatic difference-of-focus curves were obtained from best-focus data at each wavelength, and the longitudinal chromatic aberration was obtained from the slope of linear regressions to those curves. The longitudinal chromatic aberration from psychophysical measurements was 1.37 diopters (D) ± 0.08 (SD) (hydrophobic) and 1.21 ± 0.08 D (hydrophilic). From wavefront-sensing, the longitudinal chromatic aberration was 0.88 ± 0.07 D and 0.73 ± 0.09 D, respectively. At 480 to 950 nm, the longitudinal chromatic aberration was 1.27 ± 0.09 D (hydrophobic) and 1.02 ± 0.13 D (hydrophilic). The longitudinal chromatic aberration was consistently higher in eyes with the hydrophobic IOL than in eyes with the hydrophilic IOL (a difference of 0.16 D and 0.15 D, respectively). Similar to findings in young phakic eyes, the longitudinal chromatic aberration from the psychophysical method was consistently higher than from wavefront-sensing, by 0.48 D (35.41%) for the hydrophobic IOL and 0.48 D (39.43%) for the hydrophilic IOL. Longitudinal chromatic aberrations were smaller with hydrophilic IOLs than with hydrophobic IOLs of the same design. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Opacification of hydrophilic intraocular lenses after Descemet stripping automated endothelial keratoplasty

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Morgan-Warren PJ

2015-02-01

Full Text Available Peter J Morgan-Warren, Walter Andreatta, Amit K Patel Department of Ophthalmology, Solihull Hospital, Heart of England NHS Foundation Trust, Birmingham, UK Purpose: Opacification of hydrophilic acrylic intraocular lenses (IOLs is an emerging complication following Descemet stripping automated endothelial keratoplasty (DSAEK. We report six cases and review the current literature.Methods: In this retrospective, noncomparative, observational case series, patients with IOL opacification after previous DSAEK surgery were identified from corneal clinic records. Case notes were reviewed for demographic details, indication for DSAEK, IOL model, incidence of rebubbling, and postoperative course.Results: Six patients developed IOL opacification after DSAEK. All patients had Fuchs’ endothelial dystrophy and had previously received hydrophilic acrylic IOL models. Central anterior IOL opacification was noted in all six cases. Five cases (83% had required rebubbling due to dislocated graft tissue, and one had an early postoperative intraocular pressure (IOP rise. Five cases (83% were managed conservatively, and one case with a failed graft underwent redo DSAEK and IOL exchange.Conclusion: Repeated exposure to intracameral air, raised IOP, and other patient influences may be major etiological factors for IOL opacification after DSAEK. We advise avoiding hydrophilic acrylic IOL models in patients who may require future endothelial keratoplasty. Keywords: IOL, DSAEK, lamellar keratoplasty, endothelial corneal transplantation

Results of intraocular lens implantation with capsular tension ring in subluxated crystalline or cataractous lenses in children

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Das Pranab

2009-01-01

Full Text Available Purpose : To evaluate the outcome of intraocular lens (IOL implantation using capsular tension ring (CTR in subluxated crystalline or cataractous lenses in children. Setting : Tertiary care setting Materials and Methods : We prospectively studied 18 eyes of 15 children with subluxation of crystalline or cataractous lenses between 90° up to 210° after phacoemulsification, CTR and IOL implantation. Each child was examined for IOL centration, zonular dehiscence and posterior capsular opacification (PCO. Results : Age of the patient ranged between five to 15 years. Out of 18 eyes, seven had traumatic and 11 had spontaneous subluxation of crystalline or cataractous lens. Phacoemulsification was successfully performed with CTR implantation in the capsular bag. Intraoperative zonular dialysis occurred in two eyes. Anterior vitrectomy was performed in six eyes to manage vitreous prolapse. IOL implanted was polymethyl methacrylate (PMMA in eight eyes, hydrophobic acrylic in seven and hydrophilic acrylic in three. Follow-up ranged from 24 months to 72 months. Sixteen eyes had a best corrected visual acuity of 20/40 or better. Nine eyes developed significant PCO and were managed with Neodymium Yttrium Aluminum Garnet (Nd:YAG laser posterior capsulotomy. One eye with acrylic IOL in the capsular bag had IOL dislocation after two years which was managed with vitrectomy and secondary trans-scleral fixation of IOL. Conclusions : Phacoaspiration with CTR implantation makes capsular bag IOL fixation possible in most of the eyes with subluxated crystalline or cataractous lenses. PCO still remains a challenge in children with successful phacoaspiration with CTR implantation

Comparison of PMMA, foldable silicone and foldable acrylic hydrophobic intraocular lenses in combined phacoemulsification and trabeculectomy Comparação entre lentes intra-oculares de PMMA, lentes dobráveis de silicone e lentes acrílicas hidrofóbicas dobráveis em cirurgias combinadas de facoemulsificação e trabeculectomia

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Ernani Serpa Junior

2005-02-01

Full Text Available PURPOSE: To compare the postoperative results of phacotrabeculectomy with implantation of PMMA, foldable silicone or foldable hydrofobic acrylic intraocular lens (IOL. SETTING: Glaucoma unit, The Royal Liverpool University Hospital, Liverpool, United Kingdom. METHODS: We studied a total of 124 eyes of three consecutive groups of patients with glaucoma and cataract that underwent phacotrabeculectomy with implantation of a PMMA (30 eyes, a foldable silicone (57 eyes or a foldable acrylic (37 eyes IOL. Postoperative Snellen visual acuity and intraocular pressure (IOP, and early and late complications were assessed. All data were analyzed by means of c² test, Fisher's exact test, ANOVA/MANOVA tests or a combination whenever appropriate. RESULTS: In all three groups the early and late mean postoperative IOPs were significantly lower than the preoperative ones (p25 mmHg and hypotony (IOPOBJETIVO: Comparar os resultados pós-operatórios de facotrabeculectomias com implante de lentes intra-oculares de PMMA, dobráveis de silicone e acrílicas hidrofóbicas dobráveis. MÉTODOS: Estudo comparativo retrospectivo, realizado no Departamento de Glaucoma da "St. Paul's Eye Unit - The Royal Liverpool University Hospital", em Liverpool, Inglaterra, onde foram estudados um total de 124 olhos de três grupos consecutivos de pacientes com glaucoma e catarata que foram submetidos à cirurgia de facotrabeculectomia com implante de lentes intra-oculares (LIO de PMMA (30 olhos, dobráveis de silicone (57 olhos e acrílicas hidrofóbicas dobráveis (37 olhos. Foram registradas a visão e pressão intra-ocular (PIO pré e pós-operatória, assim como as complicações pós-operatórias precoces e tardias. Todos os dados foram analisados utilizando-se o teste c², teste exato de Fisher, teste de ANOVA/MANOVA ou uma combinação deles quando necessário. RESULTADOS: Nos três grupos as PIOs pós-operatórias precoces e tardias foram significativamente inferiores �

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

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

2014-09-01

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

A facile method of hydrophobic surface modification for acrylonitrile-styrene-acrylate terpolymer based on the out-migration property of metallic soaps

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Qi, Yanli; Chen, Tingting; Zhang, Jun

2018-03-01

Hydrophobic surface modification is conducted in this study by using additives with long alkyl chains. Several kinds of metallic soaps, such as calcium stearate (CaSt), zinc stearate (ZnSt), magnesium stearate (MgSt) and barium stearate (BaSt) were employed. Polymer matrix is acrylonitrile-styrene-acrylate (ASA) terpolymer due to its wonderful weather resistance property. The surface chemical characterization was studied by Fourier transformed infrared (FTIR) technology and X-ray photoelectron spectroscopy (XPS). Carboxylate (Osbnd Csbnd O-) indexes of composites in both transmittance and reflection modes were calculated according to FTIR results. As to the ratio of carboxylate index in reflection mode to that in transmittance mode, the sample added with 5 wt% ZnSt shows a higher value of 8.77, and a much higher value of 14.47 for the sample added with 10 wt% ZnSt. The corresponding Csbnd C/ Csbnd H /Cdbnd C peak areas of the samples added with 5 wt% or 10 wt% ZnSt are 75.4% and 77.3% respectively, much higher than other samples. This indicates ZnSt is much easier to out-migrate to material surface and therefore is more suitable for hydrophobic surface modification. In particular, the water contact angle of the ASA/ZnSt composite added with 10 wt% ZnSt significantly increased to 127o (40o increase in comparison with pure ASA), successfully converting the surface wettability from hydrophilic to hydrophobic.

In-the-bag capsular tension ring and intraocular lens subluxation or dislocation: a series of 23 cases.

Science.gov (United States)

Werner, Liliana; Zaugg, Brian; Neuhann, Tobias; Burrow, Michael; Tetz, Manfred

2012-02-01

To describe clinical and pathologic findings from cases of in-the-bag capsular tension ring (CTR) and intraocular lens (IOL) subluxation or dislocation. Retrospective case series with clinicopathologic correlation. Twenty-three explanted subluxated/dislocated capsular bags containing a CTR and an IOL explanted in Europe and submitted in fixative to the Berlin Eye Research Institute. Standard gross and light microscopy of specimens, complete histopathologic analyses of selected specimens done at the University of Utah, as well as questionnaire sent to explanting surgeons, and patient chart review, when available. Lens design, material, and abnormalities, capsular bag anomalies, patient demographic data, surgical dates, and presence or absence of known risk factors. Patients were aged 76.31 ± 8.24 years at explantation, which was performed 81.5 ± 32.2 months after implantation. The IOLs in these cases were 3-piece hydrophobic acrylic (N = 11), 1-piece hydrophobic acrylic (n = 6), 3-piece silicone (n = 4), or 1-piece hydrophilic acrylic (n = 2) designs; all CTRs were made of poly(methyl methacrylate). Available information on associated ocular conditions included pseudoexfoliation (n = 17), glaucoma (n = 4), vitrectomy/retina surgery (n = 3), and trauma (n = 1). Complete histopathologic assessment in 3 specimens showed signs consistent with pseudoexfoliation, without available history related to this condition in one of the cases. Moderate/severe degrees of Soemmering's ring formation and capsulorhexis phimosis were observed or reported in 13 and 11 specimens, respectively. Fourteen eyes were implanted and explanted by the same surgeon, with an interval of 92.7 ± 23.4 months between the procedures. His rate of explantation because of subluxation/dislocation was 0.76% of the CTRs implanted during the time considered. Explantation because of postoperative subluxation or dislocation of CTR-IOL-capsular bag complexes occurred approximately 6.8 years after implantation

Interactions between Therapeutic Proteins and Acrylic Acid Leachable.

Science.gov (United States)

Liu, Dengfeng; Nashed-Samuel, Yasser; Bondarenko, Pavel V; Brems, David N; Ren, Da

2012-01-01

Leachables are chemical compounds that migrate from manufacturing equipment, primary containers and closure systems, and packaging components into biopharmaceutical and pharmaceutical products. Acrylic acid (at concentration around 5 μg/mL) was detected as leachable in syringes from one of the potential vendors (X syringes). In order to evaluate the potential impact of acrylic acid on therapeutic proteins, an IgG 2 molecule was filled into a sterilized X syringe and then incubated at 45 °C for 45 days in a pH 5 acetate buffer. We discovered that acrylic acid can interact with proteins at three different sites: (1) the lysine side chain, (2) the N-terminus, and (3) the histidine side chain, by the Michael reaction. In this report, the direct interactions between acrylic acid leachable and a biopharmaceutical product were demonstrated and the reaction mechanism was proposed. Even thought a small amount (from 0.02% to 0.3%) of protein was found to be modified by acrylic acid, the modified protein can potentially be harmful due to the toxicity of acrylic acid. After being modified by acrylic acid, the properties of the therapeutic protein may change due to charge and hydrophobicity variations. Acrylic acid was detected to migrate from syringes (Vendor X) into a therapeutic protein solution (at a concentration around 5 μg/mL). In this study, we discovered that acrylic acid can modify proteins at three different sites: (1) the lysine side chain, 2) the N-terminus, and 3) the histidine side chain, by the Michael reaction. In this report, the direct interactions between acrylic acid leachable and a biopharmaceutical product were demonstrated and the reaction mechanism was proposed.

Effect of aspherical and yellow tinted intraocular lens on blue-on-yellow perimetry

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Rodrigo França de Espíndola

2012-10-01

Full Text Available PURPOSE: To investigate the possible effect of aspherical or yellow tinted intraocular lens (IOL on contrast sensitivity and blue-on-yellow perimetry. METHODS: This prospective randomized bilateral double-masked clinical study included 52 patients with visually significant bilateral cataracts divided in two groups; 25 patients (50 eyes received aspherical intraocular lens in one eye and spherical intraocular lens in the fellow eye; and 27 patients (54 eyes received ultraviolet and blue light filter (yellow tinted IOL implantation in one eye and acrylic ultraviolet filter IOL in the fellow eye. The primary outcome measures were contrast sensitivity and blue-on-yellow perimetry values (mean deviation [MD] and pattern standard deviation [PSD] investigated two years after surgery. The results were compared intra-individually. RESULTS: There was a statistically significant between-group (aspherical and spherical intraocular lens difference in contrast sensitivity under photopic conditions at 12 cycles per degree and under mesopic conditions at all spatial frequencies. There were no between-group significant differences (yellow tinted and clear intraocular lens under photopic or mesopic conditions. There was no statistically significant difference between all intraocular lens in MD or PSD. CONCLUSION: Contrast sensitivity was better under mesopic conditions with aspherical intraocular lens. Blue-on-yellow perimetry did not appear to be affected by aspherical or yellow tinted intraocular lens. Further studies with a larger sample should be carried out to confirm or not that hypotheses.

Development of a novel oxirane-acrylate composite restorative resin material

Science.gov (United States)

Sripathi Panditaradhyula, Anuhya

of these specimens were done by placing the respective specimens in distilled water, ascorbic acid (pH=1.5) and NaOH (pH=13). These resins were not fully cured with filler apart from filled 25:75 oxirane: acrylate cured best. Replacing 4-(Octyloxy) phenyl] phenyl iodonium SbF6 (OPPI) with 4-Isopropyl-4'- methyldiphenyl iodonium Tetrakis (pentafluorophenyl borate (Borate) initiator enhanced 24hr oxirane cure. Formulations had greater hardness compared with the controls. The increase in hardness was due to Increase in oxirane functionality, Increase in filler loading and use of acrylate-salinated filler. Modulus and ultimate transverse strength are greater than controls, but did not have statistically significance energy to break. Thus, these composites are as tough as controls and less brittle. They have the higher hydrophobicity than BisGMA: TEGDMA controls. Furthermore, other means of increasing hydrophobicity was explored, because higher the hydrophobicity, higher the resistance to hydrolytic degradation. Further research observations, such as dynamic mechanical analysis, should be carried out in order to determine the molecular interactions and usage of multi-walled, white carbon nanotubes as filler material.

Latex imaging by environmental STEM: application to the study of the surfactant outcome in hybrid alkyd/acrylate systems.

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Faucheu, Jenny; Chazeau, Laurent; Gauthier, Catherine; Cavaillé, Jean-Yves; Goikoetxea, Monika; Minari, Roque; Asua, José M

2009-09-01

Among other uses, latexes are a successful alternative to solvent-borne binders for coatings. Efforts are made to produce hybrid nanostructured latexes containing an acrylic phase and an alkyd phase. However, after the film-forming process, the surfactant used to stabilize these latexes remains in the film, and its location can have a drastic effect on the application properties. Among the processing parameters, the alkyd hydrophobicity can strongly influence this location. This article aims at the imaging of these surfactant molecules in two hybrid latexes with different hydrophobicity level of the alkyd resin. A first part of this paper is dedicated to the understanding of the contrast provided by the surfactant in environmental STEM imaging of latexes. Then, the influence of surfactant-polymer affinity on the surfactant location after film-forming of those hybrid alkyd/acrylate latexes is studied by this technique. It is shown that in the hybrid latex with an alkyd shell (obtained with the most hydrophilic resin), the surfactant molecules tend to remain buried in the alkyd phase. Conversely, in the hybrid latex with an acrylate shell (in the case of the most hydrophobic resin), the surfactant molecules tend to gather into islands like in pure acrylate latex films.

Aderência in vitro do Staphylococcus epidermidis e da Pseudomonas alcaligenes em lentes intra-oculares In vitro adherence of Staphylococcus epidermidis and Pseudomonas alcaligenes to intraocular lenses

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Patrícia Ioschpe Gus

2006-06-01

used in the experiment. Four of polymethylmethacrylate (PMMA, four of silicone, four of hidrogel and two of acrylic. Eight intraocular lenses were placed in eight test tubes containing 4 ml of Pseudomonas alcaligenes suspension, and six intraocular lenses were placed in six test tubes containing 4 ml of Staphylococcus epidermidis suspension. The bacterial suspension used for adherence tests was 10(8 colony-forming units per milliliter (CFU/mL which corresponds to 0.5 in the scale of McFarland. The lenses were incubated at 37° for two hours. After this, intraocular lenses were removed from the test tubes and dried twice with the use of distilled and sterile water. The material was spread on blood-agar for cultivation at 35-37°C and was evaluated every 24 hours up to 72 hours. In the samples where there was bacterial growth, the colonies were counted using the conventional laboratory methods. All assays were performed in duplicate. RESULTS: Adherence of Staphylococcus epidermidis to PMMA intraocular lenses was lower than to hydrogel and silicone intraocular lenses. Adherence of Pseudomonas alcaligenes to hydrogel intraocular lenses was lower than to PMMA, acrylic and silicone intraocular lenses. CONCLUSIONS: Results suggest that in vitro adherence of Staphylococcus epidermidis and Pseudomonas alcaligenes to intraocular lenses is influenced by type of material of the lens and by microorganism species. Bacterial adherence may play a role in the pathogenesis of some forms of endophthalmitis after cataract surgery. More in vitro and clinical studies are necessary to elucidate the mechanisms by which Staphylococcus epidermidis and Pseudomonas alcaligenes cause endophthalmitis.

Nanostructures and surface hydrophobicity of self-assembled thermosets involving epoxy resin and poly(2,2,2-trifluoroethyl acrylate)-block-poly(ethylene oxide) amphiphilic diblock copolymer.

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Yi, Fangping; Zheng, Sixun; Liu, Tianxi

2009-02-19

Poly(2,2,2-trifluoroethyl acrylate)-block-poly(ethylene oxide) (PTFEA-b-PEO) amphiphilic diblock copolymer was synthesized via the reversible addition-fragmentation transfer polymerization of 2,2,2-triffluroethyl acrylate with dithiobenzoyl-terminated poly(ethylene oxide) as a chain-transfer agent. The amphiphilic diblock copolymer was incorporated into epoxy resin to prepare the nanostructured epoxy thermosets. The nanostructures were investigated by means of atomic force microscopy, small-angle X-ray scattering, and dynamic mechanical analysis. In terms of the miscibility of the subchains of the block copolymer with epoxy after and before curing reaction, it is judged that the formation of the nanostructures follows the mechanism of self-assembly. The static contact angle measurements indicate that the nanostructured thermosets containing PTFEA-b-PEO diblock copolymer displayed a significant enhancement in surface hydrophobicity as well as a reduction in surface free energy. The improvement in surface properties was ascribed to the enrichment of the fluorine-containing subchain (i.e., PTFEA block) of the amphiphilic diblock copolymer on the surface of the nanostructured thermosets, which was evidenced by surface atomic force microscopy and energy-dispersive X-ray spectroscopy.

Anterior haptic flexing and in-the-bag subluxation of an accommodating intraocular lens due to excessive capsular bag contraction.

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Kramer, Gregory D; Werner, Liliana; Neuhann, Tobias; Tetz, Manfred; Mamalis, Nick

2015-09-01

We describe the case of a patient who had cataract surgery with implantation of the hydrophilic acrylic Tetraflex accommodating intraocular lens (IOL), with subsequent development of capsulorhexis phimosis and in-the-bag IOL subluxation. Contraction of the capsular bag secondary to fibrosis resulted in significant anterior flexing of the lens haptic component. Explantation of the IOL-capsular bag complex was required 7 years after implantation. Histopathologic analysis demonstrated multiple areas of thick anterior subcapsular fibrosis. Pseudoexfoliative material was present throughout the surface of the lens capsule. Intraocular lenses manufactured from hydrophilic acrylic material are highly flexible and may be more susceptible to capsule contraction, even in the absence of predisposing ocular and systemic conditions. This case highlights the importance of developing guidelines regarding patient screening and selection for the appropriate use of accommodating and other highly flexible IOLs. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Use of hydroxypropylmethylcellulose 2% for removing adherent silicone oil from silicone intraocular lenses

OpenAIRE

Wong , S Chien; Ramkissoon , Yashin D; Lopez , Mauricio; Page , Kristopher; Parkin , Ivan P; Sullivan , Paul M

2009-01-01

Abstract Background / aims: To investigate the effect of hydroxypropylmethylcellulose (HPMC) on the physical interaction (contact angle) between silicone oil and a silicone intraocular lens (IOL). Methods: In vitro experiments were performed, to determine the effect of HPMC (0.5%, 1% or 2%), with or without an additional simple mechanical manoeuvre, on the contact angle of silicone oil at the surface of both silicone and acrylic (control) IOLs. A balanced salt solu...

Comparison of Biofilm Formation Capacities of Two Clinical Isolates of Staphylococcus Epidermidis with and without icaA and icaD Genes on Intraocular Lenses

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Sertaç Argun Kıvanç

2017-03-01

Full Text Available Objectives: To compare biofilm formations of two Staphylococcus epidermidis (S. epidermidis isolates with known biofilm formation capacities on four different intraocular lenses (IOL that have not been studied before. Materials and Methods: Two isolates obtained from ocular surfaces and identified in previous studies and stored at -86 °C in 15% glycerol in the microbiology laboratory of the Anadolu University Department of Biology were purified and used in the study. The isolates were S. epidermidis KA 15.8 (ICA+, a known biofilm producer isolate positive for icaA, icaD and bap genes, and S. epidermidis KA 14.5 (ICA-, known as a non-biofilm producer isolate negative for icaA, icaD and bap genes. The biofilm formation capacities of the 2 isolates on 4 different IOLs were compared. Two of the IOLs were acrylic (UD613 [IOL A], Turkey; SA60AT [IOL B], USA, and the other two were polymethyl methacrylate (PMMA (B60130C [IOL C], India; B55125C [IOL D], India. Bacterial enumeration and optical density measurements were done from biofilms that formed on the IOLs. Biofilms were imaged using scanning electron microscopy. Results: Mean bacterial counts on the IOLs were 7.1±0.4 log10 CFU/mL with the ICA+ isolate, and 6.7±0.8 log10 CFU/mL with the ICA- isolate; there were no statistically significant differences. Biofilm formation was lower with acrylic lenses than PMMA lenses with both isolates (p=0.009 and p=0.013. The highest biofilm production was obtained on IOL C (PMMA (p<0.001 and the lowest was obtained on IOL A (hydrophilic acrylic (p<0.001. Conclusion: Bacterial counts after biofilm formation were lower on acrylic lenses, especially hydrophilic acrylic with hydrophobic properties. Further animal and in vivo studies are required to support the findings of this study.

Fabrication and anti-frosting performance of super hydrophobic coating based on modified nano-sized calcium carbonate and ordinary polyacrylate

Energy Technology Data Exchange (ETDEWEB)

Wang Hao [Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China); Tang Liming [Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China)], E-mail: tanglm@mail.tsinghua.edu.cn; Wu Xiaomin; Dai Wantian [Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China); Qiu Yipeng [Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China)

2007-09-15

Nano-sized calcium carbonate (CaCO{sub 3}) particles were modified by heptadecafluorodecyl trimethoxysilane under acidic water condition. An ordinary polyacrylate prepared via radical copolymerization of methyl methacrylate, butyl acrylate, acrylic acid and {beta}-hydroxyethyl methacrylate was used as the binder to form hydrophobic coatings with the modified CaCO{sub 3}. Super hydrophobic coating with water contact angle of 155{sup o} was obtained from modified CaCO{sub 3} and the polyacrylate at their weight ratio of 8/2 by a simple procedure. Based on surface analysis by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS), the super hydrophobicity can be attributed to both the surface microstructure and surface enrichment of fluoroalkyl chains. Due to a low water sliding angle, carbon black powder on super hydrophobic surface was easily removed by rolling water droplet. Furthermore, the anti-frosting performance of different surfaces was investigated, which indicated that the frost formed on superhydrophobic surface was greatly retarded compared with that on bare copper surface. The surface kept super hydrophobicity even after freezing-thawing treatment for 10 times.

Three-year incidence of Nd:YAG capsulotomy and posterior capsule opacification and its relationship to monofocal acrylic IOL biomaterial: a UK Real World Evidence study.

Science.gov (United States)

Ursell, Paul G; Dhariwal, Mukesh; Majirska, Katarina; Ender, Frank; Kalson-Ray, Shoshannah; Venerus, Alessandra; Miglio, Cristiana; Bouchet, Christine

2018-06-11

To evaluate 3-year incidence of Nd:YAG capsulotomy and PCO and compare the effect of different IOL materials. Data were retrospectively collected from seven UK ophthalmology clinics using Medisoft electronic medical records. Eyes from patients ≥65 years undergoing cataract surgery with implantation of acrylic monofocal IOLs during 2010-2013 and 3-year follow-up were analysed. Nd:YAG capsulotomy and PCO incidence proportions were reported for 3 IOL cohorts: AcrySof, other hydrophobic and hydrophilic acrylic IOLs. Unadjusted/adjusted odds ratios (OR) of Nd:YAG capsulotomy were calculated through logistic regression for non-AcrySof cohorts versus AcrySof. A sub-group analysis in single-piece IOLs (>90% of sample eyes) was also performed. The AcrySof cohort included 13,329 eyes, non-AcrySof hydrophobic 19,025 and non-AcrySof hydrophilic 19,808. The 3-year Nd:YAG capsulotomy incidence (95% CI) for AcrySof (2.4%, 2.2-2.7%) was approximately two times lower than non-AcrySof hydrophobic IOLs (4.4%, 4.1-4.7%) and approximately fourfold lower than non-AcrySof hydrophilic IOLs (10.9%, 10.5-11.3%). Trends were similar in PCO incidence (AcrySof: 4.7%; non-AcrySof hydrophobic: 6.3%; non-AcrySof hydrophilic: 14.8%). Also in the analysis restricted to single-piece IOLs, the pattern remained (2.4% vs 5.1% vs. 10.9%, respectively). Adjusted regression analysis showed a approximately two and fivefold increased odds of Nd:YAG for non-AcrySof hydrophobic and hydrophilic acrylic IOLs respectively vs. AcrySof IOLs. Nd:YAG capsulotomy ORs were similar and remained statistically significant in the single-piece IOL sub-group. Real-world evidence shows that within 3 years following implantation, AcrySof IOLs are significantly superior in reducing Nd:YAG capsulotomy and PCO incidence compared to other hydrophilic and hydrophobic acrylic IOLs.

Thiolated and S-protected hydrophobically modified cross-linked poly(acrylic acid)--a new generation of multifunctional polymers.

Science.gov (United States)

Bonengel, Sonja; Haupstein, Sabine; Perera, Glen; Bernkop-Schnürch, Andreas

2014-10-01

The aim of this study was to create a novel multifunctional polymer by covalent attachment of l-cysteine to the polymeric backbone of hydrophobically modified cross-linked poly(acrylic acid) (AC1030). Secondly, the free thiol groups of the resulting thiomer were activated using 2-mercaptonicotinic acid (2-MNA) to provide full reactivity and stability. Within this study, 1167.36 μmol cysteine and 865.72 μmol 2-MNA could be coupled per gram polymer. Studies evaluating mucoadhesive properties revealed a 4-fold extended adherence time to native small intestinal mucosa for the thiomer (AC1030-cysteine) as well as an 18-fold prolonged adhesion for the preactivated thiomer (AC1030-Cyst-2-MNA) compared to the unmodified polymer. Modification of the polymer led to a higher tablet stability concerning the thiomer and the S-protected thiomer, but a decelerated water uptake could be observed only for the preactivated thiomer. Neither the novel conjugates nor the unmodified polymer showed severe toxicity on Caco-2 cells. Evaluation of emulsification capacity proofed the ability to incorporate lipophilic compounds like medium chain triglycerides and the preservation of the emulsifying properties after the modifications. According to these results thiolated AC1030 as well as the S-protected thiolated polymer might provide a promising tool for solid and semisolid formulations in pharmaceutical development. Copyright © 2014 Elsevier B.V. All rights reserved.

Preparation and characterization of silica/fluorinated acrylate copolymers hybrid films and the investigation of their icephobicity

International Nuclear Information System (INIS)

Huang Yanfen; Hu Mingjie; Yi Shengping; Liu Xinghai; Li Houbin; Huang Chi; Luo Yunbai; Li Yan

2012-01-01

Inexpensive hydrophobic and icephobic coatings and films were obtained by a simple method. These coatings were prepared by mixing silica sol and fluorinated acrylate copolymers. There was a phase separation process in the film-forming which can provide the excellent performance. Small amount (about 2 wt.%) of fluorinated (methyl) acrylate was used in all of these coatings. The coatings were eco-friendly by using ethanol as the solvent system. Scanning electron microscopy, atomic force microscope, energy dispersive X-ray fluorescence spectrometer, water contact angle, thermal gravimetric analysis and tests of adhesion and hardness had been performed to characterize the morphological feature, chemical composition, hydrophobicity and icephobicity of the surface, thermal stability and mechanical properties of the coatings. The results showed that the films had good hydrophobicity, high thermal stability and excellent mechanical properties of adhesion strength and pencil hardness. Furthermore, by testing their properties of delaying water droplet from icing, it was found that ice formation was delayed for 90 min compared with the glass surface at − 5.6 °C. The hybrid coatings may be suitable for large-scale and practical application owing to its flexibility and simplicity. - Highlights: ► Coatings were prepared by mixing fluorinated acrylate copolymer and silica. ► Mechanical properties and anti-icing performance of the coatings were examined. ► Water contact angle increased with raising SiO 2 (sol)/monomers weight ratio. ► Ice formation was delayed for 90 min at − 5.6 °C.

Self-Assembly of Charged Amphiphilic Diblock Copolymers with Insoluble Blocks of Decreasing Hydrophobicity: From Kinetically Frozen Colloids to Macrosurfactants

Energy Technology Data Exchange (ETDEWEB)

M Jacquin; P Muller; H Cottet; O Theodoly

2011-12-31

We have investigated the self-assembly properties in aqueous solution of amphiphilic diblock copolymers with insoluble blocks of different hydrophobicity and demonstrated that the condition to obtain dynamic micelles is to design samples with insoluble blocks of low enough hydrophobicity. We focus here on results with new water-soluble amphiphilic diblock copolymers poly(diethyleneglycol ethylether acrylate)-b-poly(acrylic acid), or PDEGA-b-PAA. The physical characteristics of PDEGA-b-PAA micelles at high ionization have been determined by small angle neutron scattering (SANS). We show that PDEGA-b-PAA samples form micelles at thermodynamic equilibrium. The critical micelle concentrations (CMCs) decrease strongly with ionic strength and temperature due to a solvent quality decrease for, respectively, the corona and the core. This behavior of reversible aggregation is remarkable as compared to the behavior of kinetically frozen aggregation that has been widely observed with samples of similar architecture and different hydrophobic blocks, for example, poly(styrene)-b-poly(acrylic acid), PS-b-PAA, and poly(butyl acrylate)-b-poly(acrylic acid), PBA-b-PAA. We have measured the interfacial tension between water and the homopolymers PDEGA and PBA at, respectively, 3 and 20 mN/m at room temperature, which permits one to estimate the energy cost to extract a unimer from a micelle. The results are consistent with a micelle association that is fast for PDEGA-b-PAA and kinetically frozen PBA-b-PAA. Hence, PDEGA-b-PAA samples form a new system of synthetic charged macrosurfactant with unique properties of fast dynamic association, tunable charge, and water solubility even at temperatures and NaCl concentrations as high as 65 C and 1 M.

Increased adhesion of polydimethylsiloxane (PDMS) to acrylic adhesive tape for medical use by surface treatment with an atmospheric pressure rotating plasma jet

International Nuclear Information System (INIS)

Jofre-Reche, José Antonio; Martín-Martínez, José Miguel; Pulpytel, Jérôme; Arefi-Khonsari, Farzaneh

2016-01-01

The surface properties of polydimethylsiloxane (PDMS) were modified by treatment with an atmospheric pressure rotating plasma jet (APPJ) and the surface modifications were studied to assess its hydrophilicity and adhesion to acrylic adhesive tape intended for medical applications. Furthermore, the extent of hydrophobic recovery under different storage conditions was studied. The surface treatment of PDMS with the APPJ under optimal conditions noticeably increased the oxygen content and most of the surface silicon species were fully oxidized. A brittle silica-like layer on the outermost surface was created showing changes in topography due to the formation of grooves and cracks. A huge improvement in T-peel and the shear adhesive strength of the APPJ-treated PDMS surface/acrylic tape joints was obtained. On the other hand, the hydrophilicity of the PDMS surface increased noticeably after the APPJ treatment, but 24 h after treatment almost 80% hydrophobicity was recovered and the adhesive strength was markedly reduced with time after the APPJ treatment. However, the application of an acrylic adhesive layer on the just-APPJ-treated PDMS surface retained the adhesive strength, limiting the extent of hydrophobic recovery. (paper)

Enhanced the hydrophobic surface and the photo-activity of TiO2-SiO2 composites

Science.gov (United States)

Wahyuni, S.; Prasetya, A. T.

2017-02-01

The aim of this research is to develop nanomaterials for coating applications. This research studied the effect of various TiO2-SiO2 composites in acrylic paint to enhance the hydrophobic properties of the substrate. Titanium dioxide containing silica in the range 20-35 mol% has been synthesized using sol-gel route. The XRD’s spectra show that increasing SiO2 content in the composite, decreasing its crystalline properties but increasing the surface area. TiO2-SiO2 composite was dispersed in acrylic paint in 2% composition by weight. The largest contact angle was 70, which produced by the substrate coated with TS-35-modified acrylic paint. This study also investigated the enhanced photo-activity of TiO2-SiO2 modified with poly-aniline. The XRD spectra show that the treatment does not change the crystal structure of TiO2. The photo-activity of the composite was evaluated by degradation of Rhodamine-B with visible light. The best performance of the degradation process was handled by the composite treated with 0.1mL anilines per gram of TiO2-SiO2 composite (TSP-A). On the other side, the contact angle 70 has not shown an excellent hydrophobic activity. However, the AFM spectra showed that nanoroughness has started to form on the surface of acrylic paint modified with TiO2-SiO2 than acrylic alone.

Biocompatible Metal-Oxide Nanoparticles: Nanotechnology Improvement of Conventional Prosthetic Acrylic Resins

Directory of Open Access Journals (Sweden)

Laura S. Acosta-Torres

2011-01-01

Full Text Available Nowadays, most products for dental restoration are produced from acrylic resins based on heat-cured Poly(Methyl MethAcrylate (PMMA. The addition of metal nanoparticles to organic materials is known to increase the surface hydrophobicity and to reduce adherence to biomolecules. This paper describes the use of nanostructured materials, TiO2 and Fe2O3, for simultaneously coloring and/or improving the antimicrobial properties of PMMA resins. Nanoparticles of metal oxides were included during suspension polymerization to produce hybrid metal oxides-alginate-containing PMMA. Metal oxide nanoparticles were characterized by dynamic light scattering, and X-ray diffraction. Physicochemical characterization of synthesized resins was assessed by a combination of spectroscopy, scanning electron microscopy, viscometry, porosity, and mechanical tests. Adherence of Candida albicans cells and cellular compatibility assays were performed to explore biocompatibility and microbial adhesion of standard and novel materials. Our results show that introduction of biocompatible metal nanoparticles is a suitable means for the improvement of conventional acrylic dental resins.

Intraocular Lens Use in an Astronaut During Long Duration Spaceflight.

Science.gov (United States)

Mader, Thomas H; Gibson, C Robert; Schmid, Josef F; Lipsky, William; Sargsyan, Ashot E; Garcia, Kathleen; Williams, Jeffrey N

2018-01-01

The purpose of this paper is to report the first use of an intraocular lens (IOL) in an astronaut during long duration spaceflight (LDSF). An astronaut developed a unilateral cataract and underwent phacoemulsification with insertion of an acrylic IOL. Approximately 15 mo later he flew on a Soyuz spacecraft to the International Space Station (ISS), where he successfully completed a 6-mo mission. Ocular examination, including ultrasound (US), was performed before, during, and after his mission and he was questioned regarding visual changes during each portion of his flight. We documented no change in IOL position during his space mission. This astronaut reported excellent and stable vision during liftoff, entry into microgravity (MG), 6 mo on the ISS, descent, and landing. Our results suggest that modern IOLs are stable, effective, and well tolerated during LDSF.Mader TH, Gibson CR, Schmid JF, Lipsky W, Sargsyan AE, Garcia K, Williams JN. Intraocular lens use in an astronaut during long duration spaceflight. Aerosp Med Hum Perform. 2018; 89(1):63-65.

Effect of hydrophobic paints coating for tritium reduction in concrete materials

International Nuclear Information System (INIS)

Edao, Y.; Fukada, S.; Nishimura, Y.; Katayama, K.; Takeishi, T.; Hatano, Y.; Taguchi, A.

2012-01-01

Highlights: ► Effects of hydrophobic paint coating in tritium transport are investigated. ► Two kinds of paints, acrylic-silicon resin and epoxy resin are used. ► The hydrophobic paints are effective to reduce tritium permeation. ► The effect of tritium reduction of epoxy paint is higher than that of silicon. - Abstract: The effects of hydrophobic paint coating on a concrete material of cement paste on the tritium transport are investigated. The cement paste is coated with two kinds of paints, acrylic-silicon resin paint and epoxy resin paint. We investigated the amount of tritium trapped in the samples exposed to tritiated water vapor by means of sorption and release. It was found that both the hydrophobic paints could reduce effectively tritium permeation during 50 days exposure of tritiated water vapor. The effect of tritium reduction of the epoxy paint was higher than that of silicon while the amount of tritium trapped in the epoxy paint was larger than that of silicon due to difference of the structure. Based on an analysis of a diffusion model, the rate-determining step of tritium migration through cement paste coated with the paints is diffusion through the paints respectively. It was found that tritium was easy to penetrate through silicon because there were many pores or voids in the silicon comparatively. In the case of tritium released from the epoxy paint, it is considered that tritium diffusion in epoxy is slow due to retardation by isotope exchange reaction to water included in epoxy paint.

Comparative analysis of skin sensitization potency of acrylates (methyl acrylate, ethyl acrylate, butyl acrylate, and ethylhexyl acrylate) using the local lymph node assay.

Science.gov (United States)

Dearman, Rebecca J; Betts, Catherine J; Farr, Craig; McLaughlin, James; Berdasco, Nancy; Wiench, Karin; Kimber, Ian

2007-10-01

There are currently available no systematic experimental data on the skin sensitizing properties of acrylates that are of relevance in occupational settings. Limited information from previous guinea-pig tests or from the local lymph node assay (LLNA) is available; however, these data are incomplete and somewhat contradictory. For those reasons, we have examined in the LLNA 4 acrylates: butyl acrylate (BA), ethyl acrylate (EA), methyl acrylate (MA), and ethylhexyl acrylate (EHA). The LLNA data indicated that all 4 compounds have some potential to cause skin sensitization. In addition, the relative potencies of these acrylates were measured by derivation from LLNA dose-response analyses of EC3 values (the effective concentration of chemical required to induce a threefold increase in proliferation of draining lymph node cells compared with control values). On the basis of 1 scheme for the categorization of skin sensitization potency, BA, EA, and MA were each classified as weak sensitizers. Using the same scheme, EHA was considered a moderate sensitizer. However, it must be emphasized that the EC3 value for this chemical of 9.7% is on the borderline between moderate (10%) categories. Thus, the judicious view is that all 4 chemicals possess relatively weak skin sensitizing potential.

Spectral properties of common intraocular lens (IOL) types

Science.gov (United States)

Milne, Peter J.; Chapon, Pascal F.; Hamaoui, Marie; Parel, Jean-Marie A.; Clayman, H.; Rol, Pascal O.

1999-06-01

Currently over 50 kinds of intraocular lenses (IOLs) are approved for patient use in the treatment of cataracts and ametropia. These lenses are manufactured from at least 2 kinds of silicones as well as several kinds of acrylic polymers including polyHEMA, Poly HOXEMA, a range of polymethacrylate and polyacrylate formulations. We sought to measure spectral transmission curves of a range of IOLS in the UV-visible and near IR spectral regions in order to better characterize their optical properties and to provide a baseline from which to assess their alteration following implantation over time. Consideration of how this may best be achieved are discussed. The variable ability of both explained IOLs and some samples from a range of manufacturers to block UV wavelengths is commented upon.

Preparation and Characterization of Fluorinated Hydrophobic UV-Crosslinkable Thiol-Ene Polyurethane Coatings

Directory of Open Access Journals (Sweden)

Wenjing Xia

2017-08-01

Full Text Available The polyurethane prepolymer terminated with a double bond was synthesized using isophorone diisocyanate (IPDI, hydroxyl terminated polybutadiene (HTPB, 1,4-butanediol (BDO, and 2-hydroxyethyl acrylate (HEA. Then, a series of innovative UV-curable polyurethane coatings were prepared by blending ene-terminated polyurethane, fluoroacrylate monomer, and multifunctional thiol crosslinker upon UV exposure. The incorporation of fluoroacrylate monomer and multifunctional thiols into polyurethane coatings significantly enhanced the hydrophobic property, mechanical property, pencil hardness, and glossiness of the polyurethane coatings. This method of preparing UV crosslinkable, hydrophobic polyurethane coatings based on thiol-ene chemistry exhibited numerous advantages over other UV photocuring systems.

Radioinduced grafting of acrylic acid on expanded polystyrene matrices

International Nuclear Information System (INIS)

Postolache, C.; Simion, Corina; Dragomir, A.; Ponta, C.; Chirvasoiu, G.; Postolache, Carmen

1998-01-01

The unfixed surface radioactive contamination for low energy β radionuclides ( 3 H and 14 C) is determined by wiping the checked surfaces with sponge of absorbent materials. The activity built up by this sponge is measured by a liquid scintillator spectrometer. In this work, a method of obtaining sponges of expanded polystyrene with hydrophobic surface by radioinduced grafting of the acrylic acid is presented. These sponges have diameters of 28 mm, thicknesses of 1.5 - 2 mm and density of 22 mg/cm 3 . The samples were immersed in a grafting solution with the following composition: acrylic acid 30%, Cu SO 4 1%; water 69% which were deeply impregnated in repeated operations under vacuum and pressure conditions, respectively. Finally, the samples were exposed to γ radiation emitted by a 60 Co source (IETI 10 000 - IFIN-HH). The dose rates were 0.3, 0.5 and 1 Mrad/h. The range of the absorbed doses was 1 - 25 Mrad. The yields of radiochemical grafting have been determined by gravimetric, spectrophotometric and radiometric methods. The grafting agent used was 3 H labelled acrylic acid. The solvation capacity and the quenching characteristics of the grafted sponges in liquid scintillators, as well as the sampling yields have been analyzed as function of irradiation procedure and the percentage of grafted acrylic fragments. The superficial grafting of the acrylic acid has been carried out by the mentioned technique, leading to the increase of the wiping efficiency of the unfixed surface contaminating activity, without changes of polymer solubility in liquid scintillators and without the perturbation of the radioactivity detection process. (authors)

Bilateral intraocular lens subluxation secondary to haptic angulation.

Science.gov (United States)

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

2008-04-01

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

A pilot study to determine if intraocular lens choice at the time of cataract surgery has an impact on patient-reported driving habits

Directory of Open Access Journals (Sweden)

Beiko GHH

2015-08-01

Full Text Available George HH Beiko1,2 1Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada; 2Division of Ophthalmology, Department of Surgery, McMaster University, Hamilton, ON, CanadaPurpose: To determine if intraocular lens (IOL choice at the time of cataract surgery affects driving habits.Materials and methods: Pseudophakes who were 28–35 months postbilateral cataract surgery with one of two contemporary one-piece hydrophobic acrylic IOLs (SN60WF or ZCB00 were asked to complete the Driving Habits Questionnaire, a validated instrument for determining self-reported driving status, frequency, and difficulty. To determine if there were any differences in driving habits between the two groups, t-tests and χ2 tests were used.Results: Of 90 respondents, 72 (40 SN60WF and 32 ZCB00 were still active drivers. The SN60WF-implanted subjects were less likely to drive at the same speed or faster than the general flow of traffic, less likely to rate their quality of driving as average/above average, less likely to have traveled beyond their immediate neighborhood, less likely to drive at night, more likely to have moderate-to-severe difficulty driving at night, and more likely to have self-reported road traffic accidents. The differences did not reach statistical significance.Conclusion: Changes in patients’ driving habits 2–3 years after cataract surgery may be associated with the type of IOL implanted. A larger study, powered to demonstrate statistical significance, is needed to verify the trends identified in this pilot study and discover possible contributing factors.Keywords: intraocular lens, cataract surgery, driving habits, disability glare, retinal straylight, accidents

Adsorption and Aqueous Lubricating Properties of Charged and Neutral Amphiphilic Diblock Copolymers at a Compliant, Hydrophobic Interface

DEFF Research Database (Denmark)

Røn, Troels; Javakhishvili, Irakli; Jankova Atanasova, Katja

2013-01-01

We have investigated the adsorption and lubricating properties of neutral and charged amphiphilic diblock copolymers at a hydrophobic polydimethylsiloxane (PDMS) interface in an aqueous environment. The diblock copolymers consist of a hydrophilic block of either neutral poly(ethylene glycol) (PEG......) or negatively charged poly(acrylic acid) (PAA) and of a hydrophobic block of polystyrene (PS) or poly(2-methoxyethyl acrylate) (PMEA), thus generating PEG-b-X or PAA-b-X, where X block is either PS or PMEA. The molecular weight ratios were roughly 1:1 with each block ca. 5 kDa. Comparing the neutral PEG...... effective adsorption only when PMEA was employed as the anchoring block. For PAA-b-PS, the poor adsorption properties are chiefly attributed to micellization due to the high interfacial tension between the PS core and water. The poor lubricating properties of PAA-b-PS diblock copolymer for a PDMS...

Long-term toughness of photopolymerizable (meth)acrylate networks in aqueous environments.

Science.gov (United States)

Smith, Kathryn E; Trusty, Phillip; Wan, Beatrice; Gall, Ken

2011-02-01

Photopolymerizable (meth)acrylate networks are potentially advantageous biomaterials due to their ability to be formed in situ, their fast synthesis rates and their tailorable material properties. The objective of this study was to evaluate how immersion time in phosphate-buffered saline (PBS) affects the toughness of photopolymerizable methyl acrylate (MA)-co-methyl methacrylate-co-poly(ethylene glycol) dimethacrylate networks containing various concentrations of MA. Stress-strain behavior was determined by performing tensile strain to failure testing after soaking in PBS for different periods (1 day up to 9 months). In tandem, differential scanning calorimetry and PBS content measurements were undertaken at each time point in order to determine whether time-dependent changes in toughness were related to changes in T(g) or PBS absorption. The effect of immersion time on network toughness was shown to be dependent upon composition in a manner related to the viscoelastic state of the polymer upon initial immersion in PBS. The results demonstrate that tough acrylate-based materials may not maintain their toughness after several months in PBS. In addition, decreasing the PBS content by changing the network hydrophobicity resulted in better toughness maintenance after 9 months. The results provide a possible means to toughen various amorphous acrylate-based implant materials that are being explored for load-bearing biomedical applications, beyond the systems considered in this work. Published by Elsevier Ltd.

Synthesis and characterization of UV-absorbing fluorine-silicone acrylic resin polymer

Science.gov (United States)

Lei, Huibin; He, Deliang; Guo, Yanni; Tang, Yining; Huang, Houqiang

2018-06-01

A series of UV-absorbing fluorine-silicone acrylic resin polymers containing different amount of UV-absorbent were successfully prepared by solution polymerization, with 2-[3-(2H-Benzotriazol-2-yl)-4-hydroxyphenyl] ethyl methacrylate (BHEM), vinyltrimethoxysilane (VTMS) and hexafluorobutyl methacrylate (HFMA) as modifying monomers. The acrylic polymers and the coatings thereof were characterized by Fourier transform infrared spectrum (FT-IR), X-ray photoelectron spectroscopy (XPS), Ultraviolet-visible (UV-vis) absorption spectrum, thermogravimetric analysis (TGA), water contact angle (CA) and Xenon lamp artificial accelerated aging tests. Results indicated that the resin exhibited high UV absorption performance as well as good thermal stability. The hydrophobicity of the coatings was of great improvement because of the bonded fluorine and silicone. Meanwhile, the weather-resistance was promoted through preferably colligating the protective effects of BHEM, organic fluorine and silicone. Also, a fitting formula about the weatherability with the BMHE content was tentatively proposed.

Effect of cefuroxime and moxifloxacin on Staphylococcus epidermidis adherence to intraocular lenses.

Science.gov (United States)

Karadağ, Serhat; Ozkan, Berna; Karabaş, V Levent; Alintaş, Ozgül; Yumuk, Zeki; Cağlar, Yusuf

2009-12-01

To investigate and compare the effect of cefuroxime and moxifloxacin on adhesion of Staphylococcus epidermidis to intraocular lenses (IOLs). Experimental study. The 3-pieced hydrophobic acrylic lenses were contaminated with S. epidermidis (American Type Culture Collection 35983) solutions containing 108 colony-forming units. IOLs were inoculated into test tubes containing tryptic soy broth after being held in antibiotic solutions for 15 minutes. Sonication and vortex procedures were performed in order to remove all the remaining bacteria. From each tube 10 microL and 100 microL was taken and inoculated into sheep blood agar. The colonies were counted overnight. The statistical analyses were made using one-way ANOVA, Turkey Honestly Significant Differences test (HSD) and independent t tests, and a p value less than 0.05 was considered statistically significant. Overall, the mean numbers of colony-forming units on the lenses that were held in control, cefuroxime, moxifloxacin 0.5 mg/0.1 mL and moxifloxacin 0.1 mg/0.1 mL solutions were 1398 (SE 10.01 x 10(3)), 29.9 (SE 1.16 x 10(3)), 0.23 (SD 0.04 x 10(3)), and 0.41 (SD 0.05 x 10(3)), respectively. The evaluation using one-way ANOVA and Turkey HSD tests revealed significant statistical differences among the groups (p = 0.000). The evaluation using independent t tests revealed significant statistical differences between the 2 moxifloxacin groups (p < 0.05). Our results suggest that moxifloxacin and cefuroxime significantly inhibit bacterial adherence to IOLs. The effect of moxifloxacin on inhibition of bacterial adherence was significantly greater than that of cefuroxime. For this reason moxifloxacin might be considered as a better prophylactic agent.

Polymer-surfactant interactions studied by titration microcalorimetry : Influence of polymer hydrophobicity, electrostatic forces, and surfactant aggregational state

NARCIS (Netherlands)

Kevelam, J; van Breemen, J.F.L.; Blokzijl, W.; Engberts, J.B.F.N.

1996-01-01

Isothermal titration microcalorimetry has been applied to investigate the interactions between hydrophobically-modified water-soluble polymers and surfactants. The following polymers were used in this study: poly(sodium acrylate-co-n-alkyl methacrylate) (A), where n-alkyl = C9H19, C12H25, and C18H37

Biocompatible Metal-Oxide Nanoparticles: Nanotechnology Improvement of Conventional Prosthetic Acrylic Resins

International Nuclear Information System (INIS)

Acosta-Torres, L.S.; Lopez-Marin, L.M.; Padron, G.H.; Castano, V.M.; Nunez-Anita, R.E.

2011-01-01

Nowadays, most products for dental restoration are produced from acrylic resins based on heat-cured Poly(Methyl Methacrylate) (PMMA). The addition of metal nanoparticles to organic materials is known to increase the surface hydrophobicity and to reduce adherence to biomolecules. This paper describes the use of nano structured materials, TiO 2 and Fe 2 O 3 , for simultaneously coloring and/or improving the antimicrobial properties of PMMA resins. Nanoparticles of metal oxides were included during suspension polymerization to produce hybrid metal oxides-alginate-containing PMMA. Metal oxide nanoparticles were characterized by dynamic light scattering, and X-ray diffraction. Physicochemical characterization of synthesized resins was assessed by a combination of spectroscopy, scanning electron microscopy, viscometry, porosity, and mechanical tests. Adherence of Candida albicans cells and cellular compatibility assays were performed to explore biocompatibility and microbial adhesion of standard and novel materials. Our results show that introduction of biocompatible metal nanoparticles is a suitable means for the improvement of conventional acrylic dental resins.

Simulation of 20-year deterioration of acrylic IOLs using severe accelerated deterioration tests.

Science.gov (United States)

Kawai, Kenji; Hayakawa, Kenji; Suzuki, Takahiro

2012-09-20

To investigate IOL deterioration by conducting severe accelerated deterioration testing of acrylic IOLs. Department of Ophthalmology, Tokai University School of Medicine Methods: Severe accelerated deterioration tests performed on 7 types of acrylic IOLs simulated 20 years of deterioration. IOLs were placed in a screw tube bottle containing ultra-pure water and kept in an oven (100°C) for 115 days. Deterioration was determined based the outer appearance of the IOL in water and under air-dried conditions using an optical microscope. For accelerated deterioration of polymeric material, the elapse of 115 days was considered to be equivalent to 20 years based on the Arrhenius equation. All of the IOLs in the hydrophobic acrylic group except for AU6 showed glistening-like opacity. The entire optical sections of MA60BM and SA60AT became yellowish white in color. Hydrophilic acrylic IOL HP60M showed no opacity at any of the time points examined. Our data based on accelerated testing showed differences in water content to play a major role in transparency. There were differences in opacity among manufacturers. The method we have used for determining the relative time of IOL deterioration might not represent the exact clinical setting, but the appearance of the materials would presumably be very similar to that seen in patients.

Bioinspired bioadhesive polymers: dopa-modified poly(acrylic acid) derivatives.

Science.gov (United States)

Laulicht, Bryan; Mancini, Alexis; Geman, Nathanael; Cho, Daniel; Estrellas, Kenneth; Furtado, Stacia; Hopson, Russell; Tripathi, Anubhav; Mathiowitz, Edith

2012-11-01

The one-step synthesis and characterization of novel bioinspired bioadhesive polymers that contain Dopa, implicated in the extremely adhesive byssal fibers of certain gastropods, is reported. The novel polymers consist of combinations of either of two polyanhydride backbones and one of three amino acids, phenylalanine, tyrosine, or Dopa, grafted as side chains. Dopa-grafted hydrophobic backbone polymers exhibit as much as 2.5 × the fracture strength and 2.8 × the tensile work of bioadhesion of a commercially available poly(acrylic acid) derivative as tested on live, excised, rat intestinal tissue. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Vinyl Acetate/butyl acrylate/acrylate Research of Ternary Soap-free Emulsion Polymerization

Directory of Open Access Journals (Sweden)

Xiao Li-guang

2016-01-01

Full Text Available Through the vinyl acetate/butyl acrylate/acrylic acrylic emulsion preparation without soap vinegar, with solid content, gel, emulsion stability and film forming properties and tensile strength as the main index to study the effect of raw materials on the properties of emulsion. Through the infrared spectrometer soap-free emulsion for microscopic analysis research. Study of the ternary soap-free vinegar acrylic emulsion with good performance.

Microstructural characterization of a novel methyl acrylate-ethyl acrylate copolymer system

Energy Technology Data Exchange (ETDEWEB)

Olivares, M.; Castano, V.M. [Instituto de Fisica, UNAM, A.P. 1-1010, Queretaro, Mexico (Mexico); Molina, J.P.; Vazquez, F. [Facultad de Quimica UAEMex, Paseo Tollocan esq. Paseo Colon, Toluca, Estado de Mexico (Mexico)

1998-12-31

A number of different compositions of a novel methyl acrylate-ethyl acrylate copolymer were prepared by emulsion polymerization with potassium persulfate as initiator. The compositions synthesized were: 100/0, 75/25, 50/50, 25/75 and 0/100 on weight of methyl acrylate/ethyl acrylate at different temperatures and concentrations of initiators. The effect of other conditions were also studied. The samples were analyzed by Transmission Electron Microscopy. It was found that the size of aggregates and dispersion on sizes are controlled by the synthesis conditions, result partially supported by light scattering. (Author)

Microstructural characterization of a novel methyl acrylate-ethyl acrylate copolymer system

International Nuclear Information System (INIS)

Olivares, M.; Castano, V.M.; Molina, J.P.; Vazquez, F.

1998-01-01

A number of different compositions of a novel methyl acrylate-ethyl acrylate copolymer were prepared by emulsion polymerization with potassium persulfate as initiator. The compositions synthesized were: 100/0, 75/25, 50/50, 25/75 and 0/100 on weight of methyl acrylate/ethyl acrylate at different temperatures and concentrations of initiators. The effect of other conditions were also studied. The samples were analyzed by Transmission Electron Microscopy. It was found that the size of aggregates and dispersion on sizes are controlled by the synthesis conditions, result partially supported by light scattering. (Author)

[Comparison of four MICS intraocular lenses regarding their rates of neodymium:YAG laser capsulotomy].

Science.gov (United States)

Spyridaki, M; Höh, H

2010-03-01

The aim of this study was to evaluate the incidence of posterior capsule opacification up to 50 months following 1.7-mm bimanual MICS-cataract surgery. Bimanual MICS cataract surgery was performed in 197 eyes (135 patients) via two 1.7-mm corneal incisions. Four MICS acrylic foldable IOLs were implanted: AcriSmart 48S-5, n = 54 (Acritec GmbH, Hennigsdorf, now AT.Smart 48S Carl-Zeiss-Meditec, AG, Jena, Germany), ThinLens UltraChoice 1.0, n = 53 (Technomed GmbH, Baesweiler, Germany), AcriFlex 46, n = 41 und AcriFlex 48 CSE, n = 7 (Acrimed GmbH, Berlin, now: Lentis L-303, Oculentis GmbH, Berlin, Germany) and CareFlex, n = 43 (w2o Medizintechnik AG, Bruchsal, Germany). Statistical analysis was performed using the Kaplan-Meier technique. High levels of completeness of follow-up rates were: ThinLens 96%, CareFlex 100%, AcriSmart 93%, AcriFlex 92%. The capsulotomy rate was 43.13% for ThinLens within a mean/max. follow-up period of 801/1131 days, 34.88% for CareFlex (565/872 days), 40% for AcriSmart (988/1506 days) and 15.91% for AcriFlex (728/975 days). By limiting the follow-up period to a comparable maximum of 850 days for all four IOLs, our capsulotomy rates were as follows: ThinLens 33.33%, CareFlex 32.56 %, AcriSmart 20.0% and AcriFlex 11.36%. MICS IOLs have higher capsulotomy rates than hydrophobic acrylic lenses and sharp-edged silicone lenses. In literature comparisons MICS-IOLs do not exceed the variance levels of capsulotomy rates of PMMA, hydrophilic acrylic and silicone lenses without sharp edges. Cases of decentration or luxation of MICS-IOLs following Neodym:YAG laser capsulotomy were not detected. Capsulotomy frequency with the CareFlex was statistically significantly higher in comparison to the AcriSmart (Log Rank Mantel Cox Test, p = 0.007) and AcriFlex (log rank Mantel Cox test, p = 0.002). Capsulotomy rates observed varied for the four MICS-IOL-types tested. The posterior capsule opacification frequency of the two best MICS-IOLs (AcriFlex, Acri

Intraocular pressure reduction and regulation system

Science.gov (United States)

Baehr, E. F.; Burnett, J. E.; Felder, S. F.; Mcgannon, W. J.

1979-01-01

An intraocular pressure reduction and regulation system is described and data are presented covering performance in: (1) reducing intraocular pressure to a preselected value, (2) maintaining a set minimum intraocular pressure, and (3) reducing the dynamic increases in intraocular pressure resulting from external loads applied to the eye.

Acrylate Systemic Contact Dermatitis.

Science.gov (United States)

Sauder, Maxwell B; Pratt, Melanie D

2015-01-01

Acrylates, the 2012 American Contact Dermatitis Society allergen of the year, are found in a range of products including the absorbent materials within feminine hygiene pads. When fully polymerized, acrylates are nonimmunogenic; however, if not completely cured, the monomers can be potent allergens.A 28-year-old woman is presented, who had her teeth varnished with Isodan (Septodont, Saint-Maur-des-Fossés, France) containing HEMA (2-hydroxyethyl methacrylate) with no initial reaction. Approximately 1 month later, the patient developed a genital dermatitis secondary to her feminine hygiene pads. The initial reaction resolved, but 5 months later, the patient developed a systemic contact dermatitis after receiving a second varnishing.The patient was dramatically patch test positive to many acrylates. This case demonstrates a reaction to likely unpolymerized acrylates within a feminine hygiene pad, as well as broad cross-reactivity or cosensitivity to acrylates, and possibly a systemic contact dermatitis with systemic re-exposure to unpolymerized acrylates.

Constructing Fluorine-Free and Cost-Effective Superhydrophobic Surface with Normal-Alcohol-Modified Hydrophobic SiO2 Nanoparticles.

Science.gov (United States)

Ye, Hui; Zhu, Liqun; Li, Weiping; Liu, Huicong; Chen, Haining

2017-01-11

Superhydrophobic coatings have drawn much attention in recent years for their wide potential applications. However, a simple, cost-effective, and environmentally friendly approach is still lacked. Herein, a promising approach using nonhazardous chemicals was proposed, in which multiple hydrophobic functionalized silica nanoparticles (SiO 2 NPs) were first prepared as core component, through the efficient reaction between amino group containing SiO 2 NPs and the isocyanate containing hydrophobic surface modifiers synthesized by normal alcohols, followed by simply spraying onto various substrates for superhydrophobic functionalization. Furthermore, to further improve the mechanical durability, an organic-inorganic composite superhydrophobic coating was fabricated by incorporating cross-linking agent (polyisocyanate) into the mixture of hydrophobic-functionalized SiO 2 NPs and hydroxyl acrylic resin. The hybrid coating with cross-linked network structures is very stable with excellent mechanical durability, self-cleaning property and corrosion resistance.

Synthesis of acrylic prepolymer

International Nuclear Information System (INIS)

Hussin bin Mohd Nor; Dahlan bin Haji Mohd; Mohamad Hilmi bin Mahmood.

1988-04-01

An acrylic prepolymer was synthesized from glycidyl methacrylate (GMA), butyl methacrylate (BMA), methyl methacrylate (MMA) and acrylic acid (AA). Butyl acetate (BAc), benzoyl peroxide (BzO), 4-methoxyphenol (MPh) and triethylamine (TEA) were used as solvent, initiator, inhibitor and catalyst respectively. Observations of the synthesis leading to the formation of acrylic prepolymer are described. (author)

Intraocular (Eye) Melanoma—Health Professional Version

Science.gov (United States)

Intraocular (uveal) melanoma of the uveal tract (iris, ciliary body, and choroid), though rare, is the most common primary intraocular malignancy in adults. Find evidence-based information on intraocular melanoma treatment.

Effect of aspherical and yellow tinted intraocular lens on blue-on-yellow perimetry Efeito das lentes intraoculares asféricas e com pigmentação amarela na campimetria azul-amarelo

Directory of Open Access Journals (Sweden)

Rodrigo França de Espíndola

2012-10-01

Full Text Available PURPOSE: To investigate the possible effect of aspherical or yellow tinted intraocular lens (IOL on contrast sensitivity and blue-on-yellow perimetry. METHODS: This prospective randomized bilateral double-masked clinical study included 52 patients with visually significant bilateral cataracts divided in two groups; 25 patients (50 eyes received aspherical intraocular lens in one eye and spherical intraocular lens in the fellow eye; and 27 patients (54 eyes received ultraviolet and blue light filter (yellow tinted IOL implantation in one eye and acrylic ultraviolet filter IOL in the fellow eye. The primary outcome measures were contrast sensitivity and blue-on-yellow perimetry values (mean deviation [MD] and pattern standard deviation [PSD] investigated two years after surgery. The results were compared intra-individually. RESULTS: There was a statistically significant between-group (aspherical and spherical intraocular lens difference in contrast sensitivity under photopic conditions at 12 cycles per degree and under mesopic conditions at all spatial frequencies. There were no between-group significant differences (yellow tinted and clear intraocular lens under photopic or mesopic conditions. There was no statistically significant difference between all intraocular lens in MD or PSD. CONCLUSION: Contrast sensitivity was better under mesopic conditions with aspherical intraocular lens. Blue-on-yellow perimetry did not appear to be affected by aspherical or yellow tinted intraocular lens. Further studies with a larger sample should be carried out to confirm or not that hypotheses.OBJETIVO: Investigar a possibilidade de efeitos na sensibilidade ao contraste e nos resultados da campimetria azul-amarelo com implante de uma lente intraocular (LIO asférica ou de pigmentação amarela. MÉTODOS: Trata-se de um estudo prospectivo, randomizado, duplo-mascarado, envolvendo 52 pacientes portadores de catarata senil bilateral, divididos em dois grupos; 25

Fabrication and characterization of a novel hydrophobic CaCO{sub 3} grafted by hydroxylated poly(vinyl chloride) chains

Energy Technology Data Exchange (ETDEWEB)

Bao, Lixia [State Key Laboratory of Polymer Materials Engineering, Sichuan University (China); School of Chemical Science and Technology, Yunnan University (China); Yang, Simei; Luo, Xin [School of Chemical Science and Technology, Yunnan University (China); Lei, Jingxin [State Key Laboratory of Polymer Materials Engineering, Sichuan University (China); Cao, Qiue [School of Chemical Science and Technology, Yunnan University (China); Wang, Jiliang, E-mail: jlwang@ynu.edu.cn [School of Chemical Science and Technology, Yunnan University (China)

2015-12-01

Highlights: • Hydroxylated poly(vinyl chloride) (PVC-OH) with different molecular weight and hydroxyl value was successfully prepared by the suspension copolymerization. • PVC-OH was grafted onto the surface of CaCO{sub 3} particles by the urethane formation reaction. • The modified CaCO{sub 3} particles show excellent hydrophobicity. - Abstract: The hydroxylated PVC (PVC-OH) was successfully synthesized by a suspension polymerization of vinyl chloride (VC), butyl acrylate (BA) and hydroxyethyl acrylate (HEA). Novel hydrophobic CaCO{sub 3} was then prepared by a urethane formation reaction between methylene diphenyl diisocyanate (MDI) and the −OH groups both in the PVC-OH chains and on the surface of pristine CaCO{sub 3} particles. The effect of the PVC-OH content on the grafting ratio of treated CaCO{sub 3} particles was extensively investigated. Combining the result of Fourier transform infrared (FTIR) with that of water contact angle, it can be concluded that the hydrophobicity of CaCO{sub 3} had been efficiently improved by the PVC-OH segments grafted on the surface of CaCO{sub 3} particles. X-ray diffraction (XRD), thermal gravity analysis (TGA), scanning electron microscope (SEM) and transmission electron microscope (TEM) were also used to study crystalline behaviors, thermal stability and surface morphology of the modified CaCO{sub 3} particles, respectively. The change of specific surface area implying surface modification was investigated as well.

[Acrylic resin removable partial dentures].

Science.gov (United States)

de Baat, C; Witter, D J; Creugers, N H J

2011-01-01

An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of removable partial dentures, the acrylic resin removable partial denture has 3 favourable aspects: the economic aspect, its aesthetic quality and the ease with which it can be extended and adjusted. Disadvantages are an increased risk of caries developing, gingivitis, periodontal disease, denture stomatitis, alveolar bone reduction, tooth migration, triggering of the gag reflex and damage to the acrylic resin base. Present-day indications are ofa temporary or palliative nature or are motivated by economic factors. Special varieties of the acrylic resin removable partial denture are the spoon denture, the flexible denture fabricated of non-rigid acrylic resin, and the two-piece sectional denture. Furthermore, acrylic resin removable partial dentures can be supplied with clasps or reinforced by fibers or metal wires.

[Correlation of intraocular pressure variation after visual field examination with 24-hour intraocular pressure variations in primary open-angle glaucoma].

Science.gov (United States)

Noro, Takahiko; Nakamoto, Kenji; Sato, Makoto; Yasuda, Noriko; Ito, Yoshinori; Ogawa, Shumpei; Nakano, Tadashi; Tsuneoka, Hiroshi

2014-10-01

We retrospectively examined intraocular pressure variations after visual field examination in primary open angle glaucoma (POAG), together with its influencing factors and its association with 24-hour intraocular pressure variations. Subjects were 94 eyes (52 POAG patients) subjected to measurements of 24-hour intraocular pressure and of changes in intraocular pressure after visual field examination using a Humphrey Visual Field Analyzer. Subjects were classified into three groups according to the magnitude of variation (large, intermediate and small), and 24-hour intraocular pressure variations were compared among the three groups. Factors influencing intraocular pressure variations after visual field examination and those associated with the large variation group were investigated. Average intraocular pressure variation after visual field examination was -0.28 ± 1.90 (range - 6.0(-) + 5.0) mmHg. No significant influencing factors were identified. The intraocular pressure at 3 a.m. was significantly higher in the large variation group than other two groups (p field examination. Increases in intraocular pressure during the night might be associated with large intraocular pressure variations after visual field examination.

Latex Imaging by Environmental STEM: Application to the Study of the Surfactant Outcome in Hybrid Alkyd/Acrylate Systems

OpenAIRE

Faucheu , Jenny; Chazeau , Laurent; Gauthier , Catherine; Cavaille , Jean-Yves; Goikoetxea , Monika; Minari , Roque; Asua , Jose M.

2009-01-01

International audience; Among other uses. latexes are a successful alternative to solvent-borne binders for coatings. Efforts are made to produce hybrid nanostructured latexes containing an acrylic phase and an alkyd phase, However, after the film-forming process, the surfactant used to stabilize these latexes remains in the film, and its location can have a drastic effect on the application properties. Among the processing parameters, the alkyd hydrophobicity can strongly influence this loca...

Characteristics of the retinal images of the eye optical systems with implanted intraocular lenses

Science.gov (United States)

Siedlecki, Damian; Zając, Marek; Nowak, Jerzy

2007-04-01

Cataract, or opacity of crystalline lens in the human eye is one of the most frequent reasons of blindness nowadays. Removing the pathologically altered crystalline lens and replacing it with artificial implantable intraocular lens (IOL) is practically the only therapy in this illness. There exist a wide variety of artificial IOL types on the medical market, differing in their material and design (shape). In this paper six exemplary models of IOL's made of PMMA, acrylic and silicone are considered. The retinal image quality is analyzed numerically on the basis of Liou-Brennan eye model with these IOL's inserted. Chromatic aberration as well as polychromatic Point Spread Function and Modulation Transfer Function are calculated as most adequate image quality measures. The calculations made with Zemax TM software show the importance of chromatic aberration correction.

Dermal oncogenicity bioassays of monofunctional and multifunctional acrylates and acrylate-based oligomers.

Science.gov (United States)

DePass, L R; Maronpot, R R; Weil, C S

1985-01-01

Several important components of photocurable coatings were studied for dermal tumorigenic activity by repeated application to the skin of mice. The substances tested were 2-ethylhexyl acrylate (EHA) and methylcarbamoyloxyethyl acrylate (MCEA) (monomers); neopentyl glycol diacrylate (NPGDA), esterdiol-204-diacrylate (EDDA), and pentaerythritol tri(tetra)acrylate (PETA) (cross-linkers); and three acrylated urethane oligomers. For each bioassay, 40 C3H/HeJ male mice were dosed 3 times weekly on the dorsal skin for their lifetime with the highest dose of the test agent that caused no local irritation or reduction in body weight gain. Two negative control groups received acetone (diluent) only. A positive control group received 0.2% methylcholanthrene (MC). NPGDA and EHA had significant tumorigenic activity with tumor yields of eight and six tumor-bearing mice (three and two malignancies), respectively. The MC group had 34 mice with carcinomas and 1 additional mouse with a papilloma. MCEA had no dermal tumorigenic activity but resulted in early mortality. No skin tumors in the treatment area were observed in the other groups. Additional studies will be necessary to elucidate possible relationships between structure and tumorigenic activity for the acrylates.

Potential contact and intraocular lenses based on hydrophilic/hydrophobic sulfonated syndiotactic polystyrene membranes

Directory of Open Access Journals (Sweden)

Simona Zuppolini

2017-10-01

Full Text Available Crystalline films of syndiotactic polystyrene (s-PS, a commercially available thermoplastic polymer, having a highly hydrophilic amorphous phase, were achieved by using a mild solid-state sulfonation procedure. Despite the used mild process conditions, an easy and uniform sulfonation of the phenyl rings of the amorphous phase is obtained. The crystallinity of the polymer was not affect by the sulfonation degree (S, at least at S less than 20%, and the obtained polymer films show the nanoporous crystalline form of s-PS. As widely reported in literature, the nanoporous nature of the polymer crystalline phase gives to these materials the ability to absorb and release organic molecules of appropriate size and polarity. This property, coupled to transparency, makes these materials potentially useful intraocular lens (IOLs and contact lens applications. Sulfonation procedure and sulfonated film samples characterization by using wide-angle X-ray diffraction (WAXD, Fourier-transform infrared (FTIR and ultraviolet-visible (UV-vis spectroscopy techniques and water sorption tests were reported. Furthermore, the biocompatibility study demonstrated no cytotoxicity and appropriate cell interaction properties for the specific applications.

INTRAOCULAR LENS POSITION IN COMBINED PHACOEMULSIFICATION AND VITREORETINAL SURGERY.

Science.gov (United States)

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

2017-10-09

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

Acrylic vessel cleaning tests

International Nuclear Information System (INIS)

Earle, D.; Hahn, R.L.; Boger, J.; Bonvin, E.

1997-01-01

The acrylic vessel as constructed is dirty. The dirt includes blue tape, Al tape, grease pencil, gemak, the glue or residue form these tapes, finger prints and dust of an unknown composition but probably mostly acrylic dust. This dirt has to be removed and once removed, the vessel has to be kept clean or at least to be easily cleanable at some future stage when access becomes much more difficult. The authors report on the results of a series of tests designed: (a) to prepare typical dirty samples of acrylic; (b) to remove dirt stuck to the acrylic surface; and (c) to measure the optical quality and Th concentration after cleaning. Specifications of the vessel call for very low levels of Th which could come from tape residues, the grease pencil, or other sources of dirt. This report does not address the concerns of how to keep the vessel clean after an initial cleaning and during the removal of the scaffolding. Alconox is recommended as the cleaner of choice. This acrylic vessel will be used in the Sudbury Neutrino Observatory

Novel polymer coatings based on plasma polymerized 2-methoxyethyl acrylate

DEFF Research Database (Denmark)

Wu, Zhenning; Jiang, Juan; Benter, Maike

2008-01-01

plasma system[4]. The system named SoftPlasma™ is equipped with unique three-phase pulsed AC voltage. Low energy plasma polymerization has almost no thermal load for sensitive polymer materials[5]. Plasma polymerized coatings are highly cross-linked, pin-hole free and provide hydrophilic or hydrophobic...... properties[4-6]. We have exploited these possibilities and prepared plasma polymerized 2-methoxyethyl acrylate (PPMEA) coatings on various polymer substrates. The PPMEA coatings were optimized using various plasma polymerization conditions and characterized by X-ray photoelectron spectroscopy......, Fouriertransform infrared spectroscopy, Atomic force spectroscopy and Water contact-angle measurements. The microstructures ofPPMEA coatings with different thicknesses were also studied. For practical applications in mind, the coating stability was tested in different media (air, water, acetone, phosphate...

Aderência bacteriana in vitro a lentes intra-oculares de polimetilmetacrilato e de silicone In vitro bacterial adherence to silicone and polymetylmethacrylate intraocular lenses

Directory of Open Access Journals (Sweden)

Claudete Inês Locatelli

2004-04-01

Staphylococcus aureus ATCC 29213, Staphylococcus epidermidis (clinical isolate and Pseudomonas aeruginosa ATCC 27853 strains including growth curves, tests to verify capsule production, hydrophobicity and adherence to different materials as well as optical microscopy, scanning electronic microscopy (SEM and atomic force microscopy (AFM. RESULTS: No relation between capsule production, adherence of the strains tested and amount of microorganisms was observed; no statistically significant differences were detected between S. aureus and S. epidermidis adherence to polymetylmethacrylate and silicone intraocular lenses; P. aeruginosa was the most adherent microorganism to both materials. This adherence pattern was confirmed by SEM, while biofilm production by the three strains was visualized by AFM. CONCLUSIONS: In vitro experiments showed no differences of bacterial adherence between PMMA and silicone lenses, but P. aeruginosa displayed a greater level of adherence in relation to staphylococci. All three strains were shown to produce biofilm. Silicone was shown to be more hydrophobic when compared to polymethylmethacrylate.

Bonding auto-polymerising acrylic resin to acrylic denture teeth.

LENUS (Irish Health Repository)

Nagle, Susan

2009-09-01

This study investigated the effect of surface treatments on the shear bond strength of an auto-polymerising acrylic resin cured to acrylic denture teeth. The surface treatments included a combination of grit-blasting and\\/or wetting the surface with monomer. Samples were prepared and then stored in water prior to shear testing. The results indicated that the application of monomer to the surface prior to bonding did not influence the bond strength. Grit blasting was found to significantly increase the bond strength.

Radiation-induced graft copolymerization of methyl acrylate and acrylic acid onto rubber wood fiber

International Nuclear Information System (INIS)

Saliza Jam; Mansor Ahmad; Wan Md Zin Wan Yunus; Khairul Zaman Mohd Dahlan

2001-01-01

Graft copolymerization of methyl acrylate and acrylic acid monomers onto rubber wood fiber (RWF) was carried out by simultaneous radiation-induced technique. The parameters affecting the grafting reaction were investigated and the optimum conditions for both monomers obtained are as follows: impregnation time = 16 hours, total dose = 30 kGy, methanol : water ratio, 3:1, monomers concentration = 40 v/v % and sulphuric acid concentration = 0.1 mol/L. Fourier Transform Infrared (FTIR), thermogravimetry analysis (TGA), and scanning electron microscope (SEM) analyses used to characterize graft copolymers. The structural investigation by x-ray diffraction (XRD) shows the degree of crystallinity of rubber wood fiber decreased with the incorporation of poly(methyl acrylate) and poly(acrylic acid) grafts. (Author)

Intraocular lymphoma

Directory of Open Access Journals (Sweden)

Li-Juan Tang

2017-08-01

Full Text Available Intraocular lymphoma (IOL is a rare lymphocytic malignancy which contains two main distinct forms. Primary intraocular lymphoma (PIOL is mainly a sub-type of primary central nervous system lymphoma (PCNSL. Alternatively, IOL can originate from outside the central nervous system (CNS by metastasizing to the eye. These tumors are known as secondary intraocular lymphoma (SIOL. The IOL can arise in the retina, uvea, vitreous, Bruch’s membrane and optic nerve. There are predominantly of B-cell origin; however there are also rare T-cell variants. Diagnosis remains challenging for ophthalmologists and pathologists, due to its ability to masquerade as noninfectious or infectious uveitis, white dot syndromes, or occasionally as other metastatic cancers. Laboratory tests include flow cytometry, immunocytochemistry, interleukin detection (IL-10: IL-6, ratio >1, and polymerase chain reaction (PCR amplification. Methotrexate-based systemic chemotherapy with external beam radiotherapy and intravitreal chemotherapy with methotrexate are useful for controlling the disease, but the prognosis remains poor. Therefore, it is important to make an early diagnose and treatment. This review is focused on the clinical manifestations, diagnosis, treatment and prognosis of the IOL.

[Reasons for exchange and explantation of intraocular lenses].

Science.gov (United States)

Neuhann, I; Fleischer, F; Neuhann, T

2012-08-01

This study was performed to analyse the reasons for explantation/exchange of intraocular lenses (IOL), which had originally been implanted for the correction of aphakia during cataract extraction. All cases with IOL explantation, which had been performed at one institution between 1/2008 and 12/2009 were analysed retrospectively. A total of 105 eyes of 100 patients were analysed. The median time interval between implantation and explantation of the IOL was 5.9 years (min. 0, max. 29.6). The most frequent cause for the intervention was subluxation/dislocation of the implant in 55.2% of cases. This group comprised 21% of cases with subluxation within the capsular bag in pseudoexfoliation syndrome. Other reasons were optical problems/incorrect IOL power (21%), calcification of hydrophilic acrylic IOL (7.6%), corneal decompensation associated with an anterior chamber lens (4.8%), and single cases with varying problems. The reasons for IOL exchange presented in this study are comparable to those of other series in the literature. Explantations due to optical problems may gain weight in the future due to a rise in refractive procedures and demands. © Georg Thieme Verlag KG Stuttgart · New York.

Synthesis of Poly(styrene-acrylates-acrylic acid Microspheres and Their Chemical Composition towards Colloidal Crystal Films

Directory of Open Access Journals (Sweden)

Luis A. Ríos-Osuna

2016-01-01

Full Text Available In this paper, polystyrene colloidal microspheres have been prepared using hexyl acrylate (HA, ethylhexyl acrylate (EHA, isooctyl acrylate (IOA, butyl acrylate (BA, or isobutyl acrylate (IBA as comonomers. Microspheres with diameters from 212 to 332 nm and with a polystyrene content of 65–78% were prepared. The particles prepared in this work do not present the typical core-shell structure; as a consequence, DSC analysis showed that the microspheres exhibited only one Tg. TEM images show that the particles with comonomer content below ~30% were spherical and regular. Microspheres containing comonomer between 21 to 25% produced the less brittle films showing very iridescent colors. The films prepared from microspheres containing hexyl, ethylhexyl, and isooctyl acrylate as comonomers are firmly attached to the substrate due to their adhesive properties. The large decrease of the fragility observed in these films makes them much more attractive materials in sensing applications.

A Potentiometric Formaldehyde Biosensor Based on Immobilization of Alcohol Oxidase on Acryloxysuccinimide-modified Acrylic Microspheres

Directory of Open Access Journals (Sweden)

Lee Yook Heng

2010-11-01

Full Text Available A new alcohol oxidase (AOX enzyme-based formaldehyde biosensor based on acrylic microspheres has been developed. Hydrophobic poly(n-butyl acrylate-N-acryloxy-succinimide [poly(nBA-NAS] microspheres, an enzyme immobilization matrix, was synthesized using photopolymerization in an emulsion form. AOX-poly(nBA-NAS microspheres were deposited on a pH transducer made from a layer of photocured and self-plasticized polyacrylate membrane with an entrapped pH ionophore coated on a Ag/AgCl screen printed electrode (SPE. Oxidation of formaldehyde by the immobilized AOX resulted in the production of protons, which can be determined via the pH transducer. Effects of buffer concentrations, pH and different amount of immobilization matrix towards the biosensor’s analytical performance were investigated. The formaldehyde biosensor exhibited a dynamic linear response range to formaldehyde from 0.3–316.2 mM and a sensitivity of 59.41 ± 0.66 mV/decade (R2 = 0.9776, n = 3. The lower detection limit of the biosensor was 0.3 mM, while reproducibility and repeatability were 3.16% RSD (relative standard deviation and 1.11% RSD, respectively (n = 3. The use of acrylic microspheres in the potentiometric formaldehyde biosensor improved the biosensor’s performance in terms of response time, linear response range and long term stability when compared with thick film immobilization methods.

Poly(lauryl acrylate) and poly(stearyl acrylate) grafted multiwalled carbon nanotubes for polypropylene composites

DEFF Research Database (Denmark)

Daugaard, Anders Egede; Jankova Atanasova, Katja; Hvilsted, Søren

2014-01-01

Two new polymer grafts on an industrial grade multiwalled carbon nanotube (MWCNT) were prepared through a non-oxidative pathway employing controlled free radical polymerization for surface initiated polymer grafting. After photochemical introduction of an ATRP initiator onto the MWCNT......, polymerizations of lauryl or stearyl acrylate were performed, resulting in two novel polymer modifications on the MWCNT (poly(lauryl acrylate) or poly(stearyl acrylate)). The method was found to give time dependent loading of polymers as a function of time (up to 38 wt% for both acrylates), and showed a plateau...... in loading after 12 h of polymerization. The modified nanomaterials were melt mixed into polypropylene composites with very low filler loading (0.3 wt%), whereafter both the thermal and electrical properties were investigated by DSC and dielectric resonance spectroscopy. The electrical properties were found...

40 CFR 721.405 - Polyether acrylate.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyether acrylate. 721.405 Section... § 721.405 Polyether acrylate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polyether acrylate (PMN P-95-666) is subject to...

Pigment dispersion glaucoma induced by the chafing effect of intraocular lens haptics in Asian eyes.

Science.gov (United States)

Hong, Ying; Sun, Yan-Xiu; Qi, Hong; Zhou, Ji-Chao; Hao, Yan-Sheng

2013-03-01

To study the possible mechanism and treatment for pigment dispersion glaucoma (PDG) caused by single-piece acrylic (SPA) intraocular lens (IOL) ciliary sulcus fixation in Asian eyes. Patients referred for PDG caused by SPA IOL ciliary sulcus fixation to our hospital from April 2005 to June 2011 were included. The patients' general information, IOL type, interval between initial surgery and PDG occurrence, examination findings, antiglaucoma medicine regimen and surgical interventions were recorded. In total, six eyes from five Chinese patients were included in this study. The intraocular pressure (IOP) increased 19-30 days after cataract surgery and was not satisfactorily controlled with antiglaucoma medication. Dense pigmentation was deposited on the IOLs and on the anterior chamber angle. IOL haptic chafing was noted on the rear iris surface. IOL repositioning in the capsular bag was performed in three eyes and was combined with trabeculectomy in two eyes with progressive glaucoma. An IOL exchange with three-piece IOL ciliary sulcus fixation was performed in the other three eyes. Scanning electron microscopy of the explanted IOLs demonstrated a rough edge on the IOL haptics. SPA IOLs were not suitable for ciliary sulcus fixation. The chafing effect of the IOL haptics on the posterior iris pigment epithelium could induce PDG in Asian eyes. IOLs should be positioned in the capsular bag or a three-piece IOL should be used instead.

Synthesis of porous poly(styrene-co-acrylic acid) microspheres through one-step soap-free emulsion polymerization: whys and wherefores.

Science.gov (United States)

Yan, Rui; Zhang, Yaoyao; Wang, Xiaohui; Xu, Jianxiong; Wang, Da; Zhang, Wangqing

2012-02-15

Synthesis of porous poly(styrene-co-acrylic acid) (PS-co-PAA) microspheres through one-step soap-free emulsion polymerization is reported. Various porous PS-co-PAA microspheres with the particle size ranging from 150 to 240 nm and with the pore size ranging from 4 to 25 nm are fabricated. The porous structure of the microspheres is confirmed by the transmission electron microscopy measurement and Brunauer-Emmett-Teller (BET) analysis. The reason for synthesis of the porous PS-co-PAA microspheres is discussed, and the phase separation between the encapsulated hydrophilic poly(acrylic acid) segment and the hydrophobic polystyrene domain within the PS-co-PAA microspheres is ascribed to the pore formation. The present synthesis of the porous PS-co-PAA microspheres is anticipated to be a new and convenient way to fabricate porous polymeric particles. Copyright © 2011 Elsevier Inc. All rights reserved.

Cell adhesion of F{sup +} ion implantation of intraocular lens

Energy Technology Data Exchange (ETDEWEB)

Li, D.J. E-mail: dejunli@hotmail.com; Cui, F.Z.; Gu, H.Q

1999-04-01

The cell adhesion of ion implanted polymethylmethacrylate (PMMA) intraocular lens was studied using cultured cells in vitro. F{sup +} ion implantation was performed at the energies of 40, 60, 80, 100 keV with the fluences ranging from 5x10{sup 13} to 1x10{sup 15} ions/cm{sup 2} at room temperature. The cell adhesion tests gave interesting results that the number of the neutral granulocytes and the macrophages adhering on surface were reduced significantly after ion implantation. The optimal fluence was about 4x10{sup 14} ions/cm{sup 2}. The hydrophobicity imparted to the lens surface was also enhanced. The results of X-ray photoelectron spectroscopy analysis indicated that ion implantation resulted in the cleavage of some pendant groups, the oxidation of the surface, and the formation of some new chemical bonds, which was probably the main reason for the cell adhesion change.

[The influence of polymerization time on physicochemical properties of the acrylic resin Vertex RS].

Science.gov (United States)

Fraczak, Bogumiła; Sobolewska, Ewa; Ey-Chmielewska, Halina; Skowronek, Maria; Błazewicz, Stanisław

2009-01-01

A good denture can only be produced through proper actions during the clinical and laboratory stages of the production process. The aim of this study was to determine if a change in polymerization time affects the physicochemical properties of polymethacrylate material used for dentures. We examined the acrylic resin Vertex R.S. polymerized for 15, 25, 40, or 60 minutes. Palapress Vario was taken as reference material. Static bending, microhardness, surface wettability, and susceptibility to abrasion were determined. The microhardness test showed that most of the samples had similar Vickers hardness (VS) values, except for the sample polymerized for 25 min. which demonstrated a significantly higher value. Grindability was affected by a change in polymerization time. Mass loss was greatest for samples polymerized for 15, 25, and 60 min. and smallest for Vertex 40 and Palapress Vario. We also observed differences in the wetting angle. Vertex 40 and 60 had a relatively low wetting angle signifying that longer polymerization time results in lower hydrophobicity of the material. The present study has demonstrated that polymerization time has a significant effect on the hardness and some mechanical properties of the acrylic resin.

40 CFR 721.8082 - Polyester polyurethane acrylate.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyester polyurethane acrylate. 721... Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as polyester polyurethane acrylate...

Ultrasonic velocities, densities, and excess molar volumes of binary mixtures of N,N-dimethyl formamide with methyl acrylate, or ethyl acrylate, or butyl acrylate, or 2-ethyl hexyl acrylate at T = 308.15 K

Energy Technology Data Exchange (ETDEWEB)

Kondaiah, M. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India); Sravana Kumar, D. [Dr. V.S. Krishna Govt. Degree College, Visakhapatnam, Andhra Pradesh (India); Sreekanth, K. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India); Krishna Rao, D., E-mail: krdhanekula@yahoo.co.in [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India)

2011-12-15

Highlights: > Positive values of V{sub m}{sup E}, indicate dispersion forces between acrylic esters and DMF. > V{sub m}{sup E} values compared with Redlich-Kister polynomial. > Partial molar volumes data conclude that weak interactions exist in the systems. > Measured velocity values compared with theoretical values obtained by polynomials. - Abstract: Ultrasonic velocities, u, densities, {rho}, of binary mixtures of N,N-dimethyl formamide (DMF) with methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BA), and 2-ethyl hexyl acrylate (EHA), including pure liquids, over the entire composition range have been measured at T = 308.15 K. Using the experimental results, the excess molar volume, V{sub m}{sup E}, partial molar volumes, V-bar {sub m,1}, V-bar{sub m,2}, and excess partial molar volumes, V-bar{sub m,1}{sup E}, V-bar{sub m,2}{sup E} have been calculated. Molecular interactions in the systems have been studied in the light of variation of excess values of calculated properties. The excess properties have been fitted to Redlich-Kister type polynomial and the corresponding standard deviations have been calculated. The positive values of V{sub m}{sup E} indicate the presence of dispersion forces between the DMF and acrylic ester molecules. Further theoretical values of sound velocity in the mixtures have been evaluated using various theories and have been compared with experimental sound velocities to verify the applicability of such theories to the systems studied. Theoretical ultrasonic velocity data have been used to study molecular interactions in the binary systems investigated.

Interactions of poly(tert-butyl acrylate)-poly(styrene) diblock copolymers with lipids at the air-water interface.

Science.gov (United States)

Mudgil, Poonam; Dennis, Gary R; Millar, Thomas J

2006-08-29

Diblock copolymers with hydrophilic poly(tert-butyl acrylate) (PtBA) and hydrophobic poly(styrene) (PS) blocks were synthesized with a view to use them as a surfactant in tear film for increasing the ocular comfort in dry eye syndrome. Interactions of six PtBA-PS copolymers with four important lipids found in the tear film, namely cholesterol, cholesteryl palmitate, dipalmitoyl phosphatidylcholine, and phosphatidylinositol, were studied at the air-water interface using a Langmuir trough. Thermodynamics of mixing of the copolymers and the lipids in the mixed monolayers was determined by calculating excess free energy of mixing. The diblock copolymers showed repulsive interactions with cholesteol and cholesteryl palmitate, near neutral interactions with dipalmitoyl phosphatidylcholine, and attractive interactions with phosphatidylinositol. The lipids interacted with the PS component of the copolymer. The results indicate that a copolymer with a small hydrophilic group and a big hydrophobic group can be a likely candidate for forming stable interactions with the lipids present in the tear film and hence increase the ocular comfort.

Large Acrylic Spherical Windows In Hyperbaric Underwater Photography

Science.gov (United States)

Lones, Joe J.; Stachiw, Jerry D.

1983-10-01

Both acrylic plastic and glass are common materials for hyperbaric optical windows. Although glass continues to be used occasionally for small windows, virtually all large viewports are made of acrylic. It is easy to uderstand the wide use of acrylic when comparing design properties of this plastic with those of glass, and glass windows are relatively more difficult to fabricate and use. in addition there are published guides for the design and fabrication of acrylic windows to be used in the hyperbaric environment of hydrospace. Although these procedures for fabricating the acrylic windows are somewhat involved, the results are extremely reliable. Acrylic viewports are now fabricated to very large sizes for manned observation or optical quality instrumen tation as illustrated by the numerous acrylic submersible vehicle hulls for hu, an occupancy currently in operation and a 3600 large optical window recently developed for the Walt Disney Circle Vision under-water camera housing.

Intraocular inflammation in autoimmune diseases.

Science.gov (United States)

Pras, Eran; Neumann, Ron; Zandman-Goddard, Gisele; Levy, Yair; Assia, Ehud I; Shoenfeld, Yehuda; Langevitz, Pnina

2004-12-01

The uveal tract represents the vascular organ of the eye. In addition to providing most of the blood supply to the intraocular structures, it acts as a conduit for immune cells, particularly lymphocytes, to enter the eye. Consequently, the uveal tract is represented in many intraocular inflammatory processes. Uveitis is probably a misnomer unless antigens within the uvea are the direct targets of the inflammatory process. A better term of the condition is "intraocular inflammation" (IOI). To review the presence of IOI in autoimmune diseases, the immunopathogenic mechanisms leading to disease, and treatment. We reviewed the English medical literature by using MEDLINE (1984-2003) employing the terms "uveitis," "intraocular inflammation," and "autoimmune diseases." An underlying autoimmune disease was identified in up to 40% of patients with IOI, and included spondyloarthropathies, Behcets disease, sarcoidosis, juvenile chronic arthritis, Vogt-Koyanagi-Harada syndrome (an inflammatory syndrome including uveitis with dermatologic and neurologic manifestations), immune recovery syndrome, and uveitis with tubulointerstitial disease. The immunopathogenesis of IOI involves enhanced T-cell response. Recently, guidelines for the use of immunosuppressive drugs for inflammatory eye disease were established and include: corticosteroids, azathioprine, methotrexate, mycophenolate mofetil, cyclosporine, tacrolimus, cyclophosphamide, and chlorambucil. New therapies with limited experience include the tumor necrosis factor alpha inhibitors, interferon alfa, monoclonal antibodies against lymphocyte surface antigens, intravenous immunoglobulin (IVIG), and the intraocular delivery of immunosuppressive agents. An underlying autoimmune disease was identified in up to 40% of patients with IOI. Immunosuppressive drugs, biologic agents, and IVIG are employed for the treatment of IOI in autoimmune diseases.

Tailor-made polyfluoroacrylate and its block copolymer by RAFT polymerization in miniemulsion; improved hydrophobicity in the core-shell block copolymer.

Science.gov (United States)

Chakrabarty, Arindam; Singha, Nikhil K

2013-10-15

Controlled/living radical polymerization (CRP) of a fluoroacrylate was successfully carried out in miniemulsion by Reversible Addition Fragmentation chain Transfer (RAFT) process. In this case, 2,2,3,3,4,4,4-heptafluorobutyl acrylate (HFBA) was polymerized using 2-cyanopropyl dodecyl trithiocarbonate (CPDTC) as RAFT agent, Triton X-405 and sodium dodecyl sulfonate (SDS) as surfactant, and potassium persulphate (KPS) or 2,2'-azobis isobutyronitrile (AIBN) as initiator. Being compatible with hydrophobic fluoroacrylate, this RAFT agent offered very high conversion and good control over the molecular weight of the polymer. The miniemulsion was stable without any costabilizer. The long chain dodecyl group (-C12H25) (Z-group in the RAFT agent) had beneficial effect in stabilizing the miniemulsion. When 2-cyano 2-propyl benzodithioate (CPBD) (Z=-C6H5) was used as RAFT agent, the conversion was less and particle size distribution was very broad. Block copolymerization with butyl acrylate (BA) using PHFBA as macro-RAFT agent showed core-shell morphology with the aggregation of PHFBA segment in the shell. GPC as well as DSC analysis confirmed the formation of block copolymer. The core-shell morphology was confirmed by TEM analysis. The block copolymers (PHFBA-b-PBA) showed significantly higher water contact angle (WCA) showing much better hydrophobicity compared to PHFBA alone. Copyright © 2013 Elsevier Inc. All rights reserved.

A novel coating material that uses nano-sized SiO2 particles to intensify hydrophobicity and corrosion protection properties

International Nuclear Information System (INIS)

Ammar, Sh.; Ramesh, K.; Vengadaesvaran, B.; Ramesh, S.; Arof, A.K.

2016-01-01

Highlights: • Hybrid SiO 2 nanocomposite coatings were fabricated on mild steel. • Highest coating resistance were exhibited by coatings with 3 wt.% SiO 2 nanoparticles. • Long-term stability measurement, together with hydrophobic surface measurements, were obtained. - Abstract: The influence of SiO 2 nanoparticles on hydrophobicity and the corrosion protection capabilities of hybrid acrylic-silicone polymeric matrix have been investigated. Contact angle measurements (CA), atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (EDX) were used to study the hydrophobicity, morphology, and topography of the coatings. In addition, electrochemical impedance spectroscopy (EIS) and salt spray techniques were employed to evaluate the corrosion protection performance. A coating with 3 wt.% SiO 2 , AS 3, demonstrates significant improvement in corrosion resistance with the highest measured CA of 97.3°. Morphology and topography studies clarify the influence of nano-sized SiO 2 fillers on the surface topography and demonstrated the uniform and good distribution of the embedded SiO 2 nanoparticles within the polymeric matrix.

[Acrylic resin removable partial dentures

NARCIS (Netherlands)

Baat, C. de; Witter, D.J.; Creugers, N.H.J.

2011-01-01

An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of

21 CFR 886.3600 - Intraocular lens.

Science.gov (United States)

2010-04-01

... DEVICES OPHTHALMIC DEVICES Prosthetic Devices § 886.3600 Intraocular lens. (a) Identification. An intraocular lens is a device made of materials such as glass or plastic intended to be implanted to replace the natural lens of an eye. (b) Classification. Class III. (c) Date PMA or notice of completion of a...

21 CFR 886.4275 - Intraocular fluid.

Science.gov (United States)

2010-04-01

... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4275 Intraocular fluid. (a) Identification. An intraocular fluid is a device consisting of a nongaseous fluid intended to be introduced into the eye to aid... section 515 of the act is required before this device may be commercially distributed. See § 886.3. ...

Radiation curing applications of palm oil acrylates

International Nuclear Information System (INIS)

Mohd Hilmi Mahmood; Khairul Zaman; Rida, Anak Tajau; Mek Zah Salleh; Rosley Che Ismail

2007-01-01

Various palm oil based urethan acrylate prepolymers (UP) were prepared from palm oil based polyols, diisocyanate compounds and hydroxyl terminated acrylate monomers by following procedure derived from established methods. The products were compared with each other in term of their molecular weights (MW), viscosities, curing speed by UV irradiation, gel contents and film hardness. The molecular structure of diisocyanate compounds and hydroxyl acrylate monomers were tend to determine the molecular weights and hence viscosities of the final products of urethan acrylate prepolymers (UP), whereas, the MW of the UP has no direct effects on the UV curing properties of the prepolymers. (author)

Dynamical mechanical analysis of photocrosslinked hyperbranched urethane acrylates

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BRANKO DUNJIC

2004-06-01

Full Text Available A series of acrylate functionalized samples based on hyperbranched hydroxy-terminated polyesters with different molecular weights and different degrees of acrylation were synthesized. The obtained urethane acrylates were slightly yellow viscose liquids. Their composition was characterized by FTIR and 1H-NMR spectroscopy and their molecular weights were measured by GPC. All the synthesized samples were diluted with 25 wt.% 1,4-butanediol dimethacrylate (BDDM. The rheological properties of the uncured samples and the dynamic mechanical properties of the UV cured samples were examined. All the samples exhibit Newtonian behavior, which indicates the absence of physical entanglements in these polymers. The viscosity increases with increasing number of acrylic groups per molecule. The glass transition temperature of the UV cured samples increases with increasing the number of acrylic groups per molecule. The value of the storage modulus in the rubber-elastic plateau and the cross-link density increase with increasing number of acrylic groups per molecule. The formed networks are inhomogeneous and the residual unsaturation is the highest in the samples with the largest number of acrylic groups per molecule.

A Case Report of Intraocular Metastasis Treated with Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Kim, Ok Bae; Byun, Sang Jun; Kim, Kwang Soo; Kim, Jin Hee [Keimyung University School of Medicine, Daegu (Korea, Republic of); Lee, Ho Jun [Daegu Catholic University School of Medicine, Daegu (Korea, Republic of)

2009-09-15

Intraocular metastasis is the most common malignancy of the eye. The frequency of intraocular metastasis in all the patients dying of cancer is about 12% and ocular metastases will be detected more frequently in the future because the patients with malignant tumor are now living longer. Intraocular metastasis can cause a serious clinical problem such as blindness. The early recognition and treatment of intraocular metastasis are very important clinical oncologic issues to maintain vision and to maximize the quality of life. However, significance of intraocular metastasis is still under-evaluated for practicing oncologists. External beam radiotherapy is a safe, effective palliative treatment in terms of preserving both the vision and the eye globe.

21 CFR 886.4270 - Intraocular gas.

Science.gov (United States)

2010-04-01

... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4270 Intraocular gas. (a) Identification. An intraocular gas is a device consisting of a gaseous fluid intended to be introduced into the eye to place pressure... required. As of May 28, 1976, an approval under section 515 of the act is required before this device may...

40 CFR 721.324 - Alkoxylated acrylate polymer (generic).

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkoxylated acrylate polymer (generic... Substances § 721.324 Alkoxylated acrylate polymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkoxylated acrylate polymer...

Surface molecular aggregation structure and surface physicochemical properties of poly(fluoroalkyl acrylate) thin films

International Nuclear Information System (INIS)

Honda, K; Yamaguchi, H; Takahara, A; Kobayashi, M; Morita, M

2008-01-01

Effect of side chain length on the molecular aggregation states and surface properties of poly(fluoroalkyl acrylate)s [PFA-C y , where y is fluoromethylene number in R f group] thin films were systematically investigated. Spin-coated PFA-C y thin films were characterized by static and dynamic contact angle measurements, X-ray photoelectron spectroscopy (XPS), and grazing- incidence X-ray diffraction (GIXD). The receding contact angles showed small values for PFA-C y with short side chain (y≤6) and increased above y≥8. GIXD revealed that fluoroalkyl side chain of PFA-C y with y≥8 was crystallized and formed ordered structures at the surface region as well as bulk one. These results suggest that water repellent mechanism of PFA-C y can be attributed to the presence of highly ordered fluoroalkyl side chains at the outermost surfaces. The results of XPS in the dry and hydrated states and contact angle measurement in water support the mechanism of lowering contact angle for water by exposure of carbonyl group to the water interface through reorientation of short fluoroalkyl chains. The surface nanotextured PFA-C 8 through imprinting of anodic aluminum oxide mold showed extremely high hydrophobicity as well as high oleophobicity

21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-ethyl acrylate copolymers. 177.1320... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1320 Ethylene-ethyl acrylate copolymers. Ethylene-ethyl acrylate copolymers may be safely used to produce packaging materials, containers...

Piggyback intraocular lens implantation to correct pseudophakic refractive error after segmental multifocal intraocular lens implantation.

Science.gov (United States)

Venter, Jan A; Oberholster, Andre; Schallhorn, Steven C; Pelouskova, Martina

2014-04-01

To evaluate refractive and visual outcomes of secondary piggyback intraocular lens implantation in patients diagnosed as having residual ametropia following segmental multifocal lens implantation. Data of 80 pseudophakic eyes with ametropia that underwent Sulcoflex aspheric 653L intraocular lens implantation (Rayner Intraocular Lenses Ltd., East Sussex, United Kingdom) to correct residual refractive error were analyzed. All eyes previously had in-the-bag zonal refractive multifocal intraocular lens implantation (Lentis Mplus MF30, models LS-312 and LS-313; Oculentis GmbH, Berlin, Germany) and required residual refractive error correction. Outcome measurements included uncorrected distance visual acuity, corrected distance visual acuity, uncorrected near visual acuity, distance-corrected near visual acuity, manifest refraction, and complications. One-year data are presented in this study. The mean spherical equivalent ranged from -1.75 to +3.25 diopters (D) preoperatively (mean: +0.58 ± 1.15 D) and reduced to -1.25 to +0.50 D (mean: -0.14 ± 0.28 D; P < .01). Postoperatively, 93.8% of eyes were within ±0.50 D and 98.8% were within ±1.00 D of emmetropia. The mean uncorrected distance visual acuity improved significantly from 0.28 ± 0.16 to 0.01 ± 0.10 logMAR and 78.8% of eyes achieved 6/6 (Snellen 20/20) or better postoperatively. The mean uncorrected near visual acuity changed from 0.43 ± 0.28 to 0.19 ± 0.15 logMAR. There was no significant change in corrected distance visual acuity or distance-corrected near visual acuity. No serious intraoperative or postoperative complications requiring secondary intraocular lens removal occurred. Sulcoflex lenses proved to be a predictable and safe option for correcting residual refractive error in patients diagnosed as having pseudophakia. Copyright 2014, SLACK Incorporated.

21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be safely...

A common humoral background of intraocular and arterial blood pressure dysregulation.

Science.gov (United States)

Skrzypecki, Janusz; Grabska-Liberek, Iwona; Przybek, Joanna; Ufnal, Marcin

2018-03-01

It has been postulated that intraocular pressure, an important glaucoma risk factor, correlates positively with arterial blood pressure (blood pressure). However, results of experimental and clinical studies are often contradictory. It is hypothesized that, in some hypertensive patients, disturbances in intraocular pressure regulation may depend on biological effects of blood borne hormones underlying a particular type of hypertension, rather than on blood pressure level itself. This review compares the effects of hormones on blood pressure and intraocular pressure, in order to identify a hormonal profile of hypertensive patients with an increased risk of intraocular pressure surge. The PUBMED database was searched to identify pre-clinical and clinical studies investigating the role of angiotensin II, vasopressin, adrenaline, noradrenaline, prostaglandins, and gaseous transmitters in the regulation of blood pressure and intraocular pressure. Studies included in the review suggest that intraocular and blood pressures often follow a different pattern of response to the same hormone. For example, vasopressin increases blood pressure, but decreases intraocular pressure. In contrast, high level of nitric oxide decreases blood pressure, but increases intraocular pressure. Arterial hypertension is associated with altered levels of blood borne hormones. Contradicting results of studies on the relationship between arterial hypertension and intraocular pressure might be partially explained by diverse effects of hormones on arterial and intraocular pressures. Further studies are needed to evaluate if hormonal profiling may help to identify glaucoma-prone patients.

Effects of Novel Structure Bonding Materials on Properties of Aeronautical Acrylic

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LI Zhisheng

2017-06-01

Full Text Available Novel structure bonding materials, J-351 epoxy adhesive film with low curing temperature and liquid modified acrylate SY-50s adhesive were chosen and characterized. The effects of adhesives on the mechanical properties of acrylic were studied. The results reveal that both adhesives have excellent bonding properties to acrylic. The stress-solvent crazing value of J-351 is higher than that of SY-50s. With the application of adhesive on the surface, mechanical properties of acrylic are declined. Casting acrylic shows more drastic decline than that of oriented acrylic. Through the characterization of fracture surface, we find that fracture of tensile sample derives from the side with adhesive. Mechanical properties of acrylic are more sensitive to SY-50s, because the liquid adhesive presents integrate bonding interface with acrylic. The interface between J-351 and acrylic is clear, making acrylic insensitive to J-351 film. Edge attachment strength of samples bonded with J-351 are higher than that of samples bonded with SY-50s due to the effects of adhesives on acrylic. J-351 epoxy adhesive film presents preferable application performance in the structure bonding of aeronautical acrylic.

Advances in acrylic-alkyd hybrid synthesis and characterization

Science.gov (United States)

Dziczkowski, Jamie

2008-10-01

In situ graft acrylic-alkyd hybrid resins were formed by polymerizing acrylic and acrylic-mixed monomers in the presence of alkyds by introduction of a free radical initiator to promote graft formation. Two-dimensional NMR, specifically gradient heteronuclear multiple quantum coherence (gHMQC), was used to clarify specific graft sites of the hybrid materials. Both individual and mixed-monomer systems were produced to determine any individual monomer preferences and to model current acrylic-alkyd systems. Different classes of initiators were used to determine any initiator effects on graft location. The 2D-NMR results confirm grafting at doubly allylic hydrogens located on the fatty acid chains and the polyol segment of the alkyd backbone. The gHMQC spectra show no evidence of grafting across double bonds on either pendant fatty acid groups or THPA unsaturation sites for any of the monomer or mixed monomer systems. It was also determined that choice of initiator has no effect on graft location. In addition, a design of experiments using response surface methodology was utilized to obtain a better understanding of this commercially available class of materials and relate both the chemical and physical properties to one another. A Box-Behnkin design was used, varying the oil length of the alkyd phase, the degree of unsaturation in the polyester backbone, and acrylic to alkyd ratio. Acrylic-alkyd hybrid resins were reduced with an amine/water mixture. Hydrolytic stability was tested and viscoelastic properties were obtained to determine crosslink density. Cured films were prepared and basic coatings properties were evaluated. It was found that the oil length of the alkyd is the most dominant factor for final coatings properties of the resins. Acrylic to alkyd ratio mainly influences the resin properties such as acid number, average molecular weight, and hydrolytic stability. The degree of unsaturation in the alkyd backbone has minimal effects on resin and film

The Synthesis of Backbone Thermo and pH Responsive Hyperbranched Poly(Bis(N,N-Propyl Acryl Amides by RAFT

Directory of Open Access Journals (Sweden)

Shijiao Zhou

2016-04-01

Full Text Available Hyperbranched poly(methylene-bis-acrylamide, poly(bis(N,N-propyl acryl amide (HPNPAM and poly(bis(N,N-butyl acryl amide were synthesized by reversible addition-fragmentation chain transfer polymerization. HPNPAMs showed lower critical solution temperature (LCST due to an appropriate ratio between hydrophilic and hydrophobic groups. The effects of reaction conditions on polymerization were investigated in detail. The structure of HPNPAM was characterized by 1H NMR, FT-IR, Muti detector-size exclusion chromatography (MDSEC and Ultravioletvisble (UV-Vis. The α value reached 0.20 and DB was 90%, indicating HPNPAMs with compact topology structure were successfully prepared. LCSTs were tuned by Mw and the pH value of the solution. The change of molecular size was assayed by dynamic light scattering and scanning electron microscope. These results indicated that the stable uniform nanomicelles were destroyed and macromolecules aggregated together, forming large particles as temperature exceeded LCST. In addition, after the cells were incubated for 24 h, the cell viability reached 80%, which confirmed this new dual responsive HPNPAM had low cytotoxicity.

Effects of composition and layer thickness of a butyl acrylate/acrylic acid copolymer on the adhesion properties

Energy Technology Data Exchange (ETDEWEB)

Ghim, Deoukchen; Kim, Jung Hyeun [University of Seoul, Seoul (Korea, Republic of)

2016-02-15

Acrylic pressure-sensitive adhesives are synthesized by solution copolymerization using n-butyl acrylate and acrylic acid (AA) in ethyl acetate anhydrous. The copolymer composition is controlled for good adhesive properties by varying AA content. The monomer conversion is measured by the gravimetric method and FTIR technique. The adhesive layer thickness is measured by scanning electron microscopy, and the adhesive properties are evaluated with loop tack, 180 .deg. peel, and holding time measurements. The peel force increases with increasing the AA content up to 3 wt% and decreases at the AA content higher than 3 wt%, but the tack force decreases with increasing the AA content. The holding time increases with increasing the AA content, and it shows a similar trend with the T{sub g} of adhesives. The increase of layer thickness improves tack and peel forces, but it weakens the holding power. A tape thickness of about 20 μm shows well-balanced properties at 3 wt% AA content in the acrylic copolymer system.

Effects of composition and layer thickness of a butyl acrylate/acrylic acid copolymer on the adhesion properties

International Nuclear Information System (INIS)

Ghim, Deoukchen; Kim, Jung Hyeun

2016-01-01

Acrylic pressure-sensitive adhesives are synthesized by solution copolymerization using n-butyl acrylate and acrylic acid (AA) in ethyl acetate anhydrous. The copolymer composition is controlled for good adhesive properties by varying AA content. The monomer conversion is measured by the gravimetric method and FTIR technique. The adhesive layer thickness is measured by scanning electron microscopy, and the adhesive properties are evaluated with loop tack, 180 .deg. peel, and holding time measurements. The peel force increases with increasing the AA content up to 3 wt% and decreases at the AA content higher than 3 wt%, but the tack force decreases with increasing the AA content. The holding time increases with increasing the AA content, and it shows a similar trend with the T g of adhesives. The increase of layer thickness improves tack and peel forces, but it weakens the holding power. A tape thickness of about 20 μm shows well-balanced properties at 3 wt% AA content in the acrylic copolymer system.

Dataset for acrylate/silica nanoparticles formulations and photocured composites: Viscosity, filler dispersion and bulk Poisson׳s ratio

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Hubert Gojzewski

2017-06-01

Full Text Available UV-curable polymer composites are of importance in industry, biomedical applications, scientific fields, and daily life. Outstanding physical properties of polymer composites were achieved with nanoparticles as filler, primarily in enhancing mechanical strength or barrier properties. Structure-property relationships of the resulting nanocomposites are dictated by the polymer-filler molecular architecture, i.e. interactions between polymer matrix and filler, and high surface area to volume ratio of the filler particles. Among monomers, acrylates and methacrylates attracted wide attention due to their ease of polymerization and excellent physicochemical and mechanical properties of the derived polymers. We prepared and photopolymerized two series of formulations containing hydrophobized silica nanofiller (Aerosil R7200 dispersed in 2-hydroxyethyl acrylate (HEA or polyethylene glycol diacrylate (PEGDA monomers. We compared selected physical properties of the formulations, both before and after photocuring; specifically the viscosity of formulations and dispersion of the filler in the polymer matrices. Additionally, we estimated the bulk Poisson׳s ratio of the investigated nanocomposites. This article contains data related to the research article entitled “Nanoscale Young׳s modulus and surface morphology in photocurable polyacrylate/nanosilica composites” (Gojzewski et al., 2017 [1].

21 CFR 886.4300 - Intraocular lens guide.

Science.gov (United States)

2010-04-01

...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4300 Intraocular lens guide. (a) Identification. An intraocular lens guide is a device intended to be inserted into the eye during surgery to direct... lenses, the device is exempt from the premarket notification procedures in subpart E of part 807 of this...

Amylase catalyzed synthesis of glycosyl acrylates and their polymerization

NARCIS (Netherlands)

Kloosterman, Wouter M.J.; Jovanovic, Danijela; Brouwer, Sander; Loos, Katja

2014-01-01

The enzymatic synthesis of novel (di)saccharide acrylates from starch and 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate and 4-hydroxybutyl acrylate (2-HEA, 2-HEMA and 4-HBA) catalyzed by various commercially available amylase preparations is demonstrated. Both liquefaction and

Waterborne hyperbranched alkyd-acrylic resin obtained by miniemulsion polymerization

Directory of Open Access Journals (Sweden)

Edwin Murillo

Full Text Available Abstract Four waterborne hyperbranched alkyd-acrylic resins (HBRAA were synthesized by miniemulsion polymerization from a hyperbranched alkyd resin (HBR, methyl methacrylate (MMA, butyl acrylate (BA and acrylic acid (AA, by using benzoyl peroxide (BPO and ammonium persulfate (AP as initiators. The reaction between HBR and acrylic monomers was evidenced by differential scanning calorimetric (DSC, nuclear magnetic resonance (NMR and gel permeation chromatography (GPC. The conversion percentage, glass transition temperature (Tg, content of acrylic polymer (determined by soxhlet extraction and molecular weight increased with the content of acrylic monomers used in the synthesis. The main structure formed during the synthesis was the HBRAA. The analysis by dynamic light scattering (DLS showed that the particle size distribution of HBRAA2, HBRAA3 and HBRAA4 resins were mainly monomodal. The film properties (gloss, flexibility, adhesion and drying time of the HBRAA were good.

Allergic contact dermatitis to acrylates in disposable blue diathermy pads.

Science.gov (United States)

Sidhu, S. K.; Shaw, S.

1999-01-01

We report 2 cases of elicitation of allergic contact dermatitis to acrylates from disposable blue diathermy pads used on patients who underwent routine surgery. Their reactions were severe, and took approximately 5 weeks to resolve. Both patients gave a prior history of finger tip dermatitis following the use of artificial sculptured acrylic nails, which is a common, but poorly reported, cause of acrylate allergy. Patch testing subsequently confirmed allergies to multiple acrylates present in both the conducting gel of disposable blue diathermy pads, and artificial sculptured acrylic nails. We advocate careful history taking prior to surgery to avoid unnecessary exposure to acrylates in patients already sensitized. Images Figure 1 Figure 2 PMID:10364952

DESIGN AND CONTROL OF SOAP-FREE HYDROPHILIC-HYDROPHOBIC CORE-SHELL LATEX PARTICLES WITH HIGH CARBOXYL CONTENT IN THE CORE OF THE PARTICLES

Institute of Scientific and Technical Information of China (English)

Wen-jiao Ji; Yi-ming Jiang; Bo-tian Li; Wei Deng; Cheng-you Kan

2012-01-01

Soap-free hydrophilic-hydrophobic core-shell latex particles with high carboxyl content in the core of the particles were synthesized via the seeded emulsion polymerization using methyl methacrylate (MMA),butyl acrylate (BA),methacrylic acid (MAA),styrene (St) and ethylene glycol dimethacrylate (EGDMA) as monomers,and the influences of MMA content used in the core preparation on polymerization,particle size and morphology were investigated by transmission electron microscopy,dynamic light scattering and conductometric titration.The results showed that the seeded emulsion polymerization could be carried out smoothly using "starved monomer feeding process" when MAA content in the core preparation was equal to or less than 24 wt％,and the encapsulating efficiency of the hydrophilic P(MMA-BA-MAA-EGDMA) core with the hydrophobic PSt shell decreased with the increase in MAA content.When an interlayer of P(MMA-MAA-St) with moderate polarity was inserted between the P(MMA-BA-MAA-EGDMA) core and the PSt shell,well designed soap-free hydrophilic-hydrophobic core-shell latex particles with 24 wt％ MAA content in the core preparation were obtained.

DESIGN OF THE MULTIORDER INTRAOCULAR LENSES

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V. G. Kolobrodov

2015-01-01

Full Text Available Intraocular lenses (IOLs are used to replace the natural crystalline lens of the eye. Just few basic designs of IOLs are used clinically. Multiorder diffractive lenses (MODL which operate simultaneously in several diffractive orders were proposed to decrease the chromatic aberration. Properties analysis of MODL showed a possibility to use them to develop new designs of IOLs. The purpose of this paper was to develop a new method of designing of multiorder intraocular lenses with decreased chromatic aberration. The theoretical research of the lens properties was carried out. The diffraction efficiency dependence with the change of wavelength was studied. A computer simulation of MODL in a schematic model of the human eye was carried out. It is found the capability of the multiorder diffractive lenses to focus polychromatic light into a segment on the optical axis with high diffraction efficiency. At each point of the segment is present each component of the spectral range, which will build a color image in combination. The paper describes the new design method of intraocular lenses with reduced chromaticism and with endless adaptation. An optical system of an eye with an intraocular lens that provides sharp vision of objects located at a distance of 700 mm to infinity is modeled.

Palm oil based polyols for acrylated polyurethane production

International Nuclear Information System (INIS)

Rida Tajau; Mohd Hilmi Mahmood; Mek Zah Salleh; Khairul Zaman Mohd Dahlan; Rosley Che Ismail

2006-01-01

Palm oil becomes important renewable resources for the production of polyols for the polyurethane manufacturing industry. The main raw materials used for the production of acrylated polyurethane are polyols, isocyanates and hydroxyl terminated acrylate compounds. In these studies, polyurethane based natural polymer (palm oil), i.e., POBUA (Palm Oil Based Urethane Acrylate) were prepared from three different types of palm oil based polyols i.e., epoxidised palm oil (EPOP), palm oil oleic acid and refined, bleached and deodorized (RBD) palm olein based polyols. The performances of these three acrylated polyurethanes when used for coatings and adhesives were determined and compared with each other. (Author)

Lente intra-ocular multifocal difrativa apodizada: resultados Diffractive apodized multifocal intraocular lens: results

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Virgilio Centurion

2007-12-01

Full Text Available OBJETIVO: Mostrar os resultados visuais e refracionais com lente intra-ocular multifocal difrativa apodizada. MÉTODOS: Estudo de 100 olhos de 50 pacientes com catarata, submetidos à facoemulsificação com implante bilateral de lente intra-ocular (LIO multifocal difrativa apodizada. Foi avaliada a acuidade visual binocular sem e com correção para longe e perto, a previsibilidade refracional e a freqüência de uso de óculos. RESULTADOS: A acuidade visual sem correção para longe foi de e " 20/30 em 97,56% dos olhos operados e e" J2 em 100%, sendo que 82% dos pacientes nunca usam óculos e 16% usam de forma esporádica. CONCLUSÃO: A LIO multifocal difrativa apodizada mostrou ser uma opção previsível, reproduzível e segura na correção dos vícios de refração para longe e perto durante a cirurgia da catarata, permitindo elevado índice de independência ao uso de óculos.OBJECTIVE: To show visual and refraction results using multifocal diffractive apodized intraocular lens. METHODS: The study of 100 eyes of 50 patients with cataract, submitted to phacoemulsification with bilateral implant of multifocal diffractive apodized intraocular lens (IOL. Binocular visual acuity was evaluated with and without correction for near and distance, and refraction previsibility and frequency of wearing glasses. RESULTS: Visual acuity without correction for distance was e" 20/30 in 97.56% of eyes operated on and e" J2 in 100%, of these 82% of patients never wear glasses and 16% wear glasses sporadically. CONCLUSION: Multifocal diffractive apodized IOL proved to be a foreseeable option, reproducible and safe in the correction of refraction errors for distance and near during cataract surgery, enabling a high rate of independence from the use of glasses.

Bond strength test of acrylic artificial teeth with prosthetic base

Directory of Open Access Journals (Sweden)

Erna Kurnikasari

2008-07-01

Full Text Available Denture consists of acrylic artificial teeth and acrylic prothesis base bond chemically with a bond strength of 315 kgF/cm2. Most of the commercial acrylic artificial teeth do not specify their specifications and all of those acrylic artificial teeth do not include mechanical data (bond strength. The aim of this study is to discover which acrylic artificial teeth meet ADA specification no. 15. This study is a descriptive analytic study performed to 5 acrylic artificial teeth posterior brands commonly used by dentists and technicians. From each brand, 3 sample teeth were taken. The acrylic artificial teeth were prepared into a rectangular shape and were attached between acrylic prothesis base simulation and jigs. The sample was given tensile load using a Universal Testing Machine. The amount of force that causes the teeth to be fractured was recorded and the bond strength was calculated. The results of the study show that the average value for the five acrylic artificial teeth for the five brands were as followed: Brand A, 125.993 kgF/cm2; B, 188.457 kgF/cm2; C, 175.880 kgF/cm2; D, 153.373 kgF/cm2; E, 82.839 kgF/cm2. The data can be tested statistically by using One Way ANOVA test and Dunnett test (alpha = 0.05. From the study, it is concluded that the five acrylic artificial teeth have a bond strength below the ADA specification no. 15.

Single-suture scleral fixation of subluxated foldable intraocular lenses.

Science.gov (United States)

Yarangumeli, Alper; Alp, Mehmet Numan; Kural, Gulcan

2012-01-01

To evaluate the results of single-suture scleral fixation of subluxated foldable intraocular lenses (IOL) in eyes with sufficient residual capsular support. The results of IOL repositioning by single-suture scleral fixation in 6 eyes of 6 patients with IOL subluxation were included. All subluxated IOLs were single-piece hydrophilic acrylic. Subluxation resulted from posterior capsule tears in 3 eyes, zonular dialyses in 2 eyes, and zonular dialysis with a capsulorhexis tear in 1 eye. A similar technique was used in all eyes in which one haptic was externalized through a superior clear corneal incision and tied with a Pair-PAK 10-0 polypropylene suture, and was finally retracted and fixated behind the iris close to the ciliary sulcus at the 12:00 meridian. All patients were followed up for at least 6 months. Best-corrected visual acuities ranged between finger counting and 20/70 (mean logMAR 1.02±0.64) preoperatively, and between 20/100 and 20/20 (mean logMAR 0.22±0.26) at the final postoperative visit. All IOLs remained centered and no significant postoperative complications were encountered except for an IOL tilt which resulted in a considerable oblique astigmatism in one eye. Subluxated foldable IOLs may safely be repositioned and secured with a single scleral fixation suture in selected cases with adequate amount of capsular remnants.

Analysis of poly(styrene-co-methyl acrylate) and poly(styrene-co-butyl acrylate) by high-performance liquid chromatography

NARCIS (Netherlands)

Sparidans, R.W.; Claessens, H.A.; van Doremaele, G.H.J.; Herk, van A.M.

1990-01-01

Poly(styrene—co-methyl acrylate) and poly(styrene—co-butyl acrylate) were separated according to their chemical composition by gradient elution. The chromatographic separation on silica was optimized for a gradient ranging from n-heptane as a non-solvent to dichloromethane containing a small amount

Relation between intraocular pressure and size of transverse sinuses

Energy Technology Data Exchange (ETDEWEB)

Kantarci, Mecit; Onbas, Omer; Alper, Fatih; Okur, Adnan [Atatuerk University, Department of Radiology, Medical Faculty, Erzurum (Turkey); Dane, Senol; Gumustekin, Kenan [Atatuerk University, Department of Physiology, Medical Faculty, Erzurum (Turkey); Aslankurt, Murat [Atatuerk University, Department of Ophtalmatology, Medical Faculty, Erzurum (Turkey); Yazici, Ahmet Taylan [Beyoglu Goez Egitim ve Arastirma Hastanesi, Istanbul (Turkey)

2005-01-01

There are asymmetries in the sizes of transverse sinus and intraocular pressure. The purpose of this study was to investigate possible relationships between the asymmetry of transverse sinuses in TOF MR venography and intraocular pressures of right and left eyes. In this study, subjects were 63 male and 42 female medical school students, aged 18-21 years (mean{+-}SD; 19.72{+-}0.67 years). Subjects with neurological and ophthalmologic disease, particularly dural sinus thrombosis, myopia, trauma and glaucoma, were excluded the study. Subjects were divided into five groups according to the magnitudes of the right- and left-transverse sinuses in MR venography results. There is a functional relation between intraocular pressures of the right and left eyes and asymmetry of the transverse sinus. If the transverse sinus on one side is larger and its venous drainage is greater, the intraocular pressure of the eye on this side is lower. It can be speculated that the transverse sinus size may be associated with pathogenesis of diseases with increased intraocular pressure such as glaucoma. We aim to determine the relation between the size and drainage of transverse sinuses in TOF MR venography and intraocular pressure in patients with open-angle glaucoma in our next study. (orig.)

Relation between intraocular pressure and size of transverse sinuses

International Nuclear Information System (INIS)

Kantarci, Mecit; Onbas, Omer; Alper, Fatih; Okur, Adnan; Dane, Senol; Gumustekin, Kenan; Aslankurt, Murat; Yazici, Ahmet Taylan

2005-01-01

There are asymmetries in the sizes of transverse sinus and intraocular pressure. The purpose of this study was to investigate possible relationships between the asymmetry of transverse sinuses in TOF MR venography and intraocular pressures of right and left eyes. In this study, subjects were 63 male and 42 female medical school students, aged 18-21 years (mean±SD; 19.72±0.67 years). Subjects with neurological and ophthalmologic disease, particularly dural sinus thrombosis, myopia, trauma and glaucoma, were excluded the study. Subjects were divided into five groups according to the magnitudes of the right- and left-transverse sinuses in MR venography results. There is a functional relation between intraocular pressures of the right and left eyes and asymmetry of the transverse sinus. If the transverse sinus on one side is larger and its venous drainage is greater, the intraocular pressure of the eye on this side is lower. It can be speculated that the transverse sinus size may be associated with pathogenesis of diseases with increased intraocular pressure such as glaucoma. We aim to determine the relation between the size and drainage of transverse sinuses in TOF MR venography and intraocular pressure in patients with open-angle glaucoma in our next study. (orig.)

Concentration and fractionation of hydrophobic organic acid constituents from natural waters by liquid chromatography

Science.gov (United States)

Thurman, E.M.; Malcolm, R.L.

1979-01-01

A scheme is presented which used adsorption chromatography with pH gradient elution and size-exclusion chromatography to concentrate and separate hydrophobic organic acids from water. A review of chromatographic processes involved in the flow scheme is also presented. Organic analytes which appear in each aqueous fraction are quantified by dissolved organic carbon analysis. Hydrophobic organic acids in a water sample are concentrated on a porous acrylic resin. These acids usually constitute approximately 30-50 percent of the dissolved organic carbon in an unpolluted water sample and are eluted with an aqueous eluent (dilute base). The concentrate is then passed through a column of polyacryloylmorpholine gel, which separates the acids into high- and low-molecular-weight fractions. The high- and low-molecular-weight eluates are reconcentrated by adsorption chromatography, then are eluted with a pH gradient into strong acids (predominately carboxylic acids) and weak acids (predominately phenolic compounds). For standard compounds and samples of unpolluted waters, the scheme fractionates humic substances into strong and weak acid fractions that are separated from the low molecular weight acids. A new method utilizing conductivity is also presented to estimate the acidic components in the methanol fraction.

Release of a Poorly Soluble Drug from Hydrophobically Modified Poly (Acrylic Acid in Simulated Intestinal Fluids.

Directory of Open Access Journals (Sweden)

Patrik Knöös

Full Text Available A large part of new pharmaceutical substances are characterized by a poor solubility and high hydrophobicity, which might lead to a difference in drug adsorption between fasted and fed patients. We have previously evaluated the release of hydrophobic drugs from tablets based on Pemulen TR2 and showed that the release can be manipulated by adding surfactants. Here we further evaluate the possibility to use Pemulen TR2 in controlled release tablet formulations containing a poorly soluble substance, griseofulvin. The release is evaluated in simulated intestinal media that model the fasted state (FaSSIF medium or fed state (FeSSIF. The rheology of polymer gels is studied in separate experiments, in order to gain more information on possible interactions. The release of griseofulvin in tablets without surfactant varied greatly and the slowest release were observed in FeSSIF. Addition of SDS to the tablets eliminated the differences and all tablets showed a slow linear release, which is of obvious relevance for robust drug delivery. Comparing the data from the release studies and the rheology experiment showed that the effects on the release from the different media could to a large extent be rationalised as a consequence of the interactions between the polymer and the surfactants in the media. The study shows that Pemulen TR2 is a candidate for controlled release formulations in which addition of surfactant provides a way to eliminate food effects on the release profile. However, the formulation used needs to be designed to give a faster release rate than the tablets currently investigated.

Contact allergy to epoxy (meth)acrylates.

Science.gov (United States)

Aalto-Korte, Kristiina; Jungewelter, Soile; Henriks-Eckerman, Maj-Len; Kuuliala, Outi; Jolanki, Riitta

2009-07-01

Contact allergy to epoxy (meth)acrylates, 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (bis-GMA), 2,2-bis[4-(2-hydroxy-3-acryloxypropoxy)phenyl]-propane (bis-GA), 2,2-bis[4-(methacryl-oxyethoxy)phenyl] propane (bis-EMA), 2,2-bis[4-(methacryloxy)phenyl]-propane (bis-MA), and glycidyl methacrylate (GMA) is often manifested together with contact allergy to diglycidyl ether of bisphenol A (DGEBA) epoxy resin. To analyse patterns of concomitant allergic reactions to the five epoxy (meth)acrylates in relation to exposure. We reviewed the 1994-2008 patch test files at the Finnish Institute of Occupational Health (FIOH) for reactions to the five epoxy (meth)acrylates, and examined the patients' medical records for exposure. Twenty-four patients had an allergic reaction to at least one of the studied epoxy (meth)acrylates, but specific exposure was found only in five patients: two bis-GMA allergies from dental products, two bis-GA allergies from UV-curable printing inks, and one bis-GA allergy from an anaerobic glue. Only 25% of the patients were negative to DGEBA epoxy resin. The great majority of allergic patch test reactions to bis-GMA, bis-GA, GMA and bis-EMA were not associated with specific exposure, and cross-allergy to DGEBA epoxy resin remained a probable explanation. However, independent reactions to bis-GA indicated specific exposure. Anaerobic sealants may induce sensitization not only to aliphatic (meth)acrylates but also to aromatic bis-GA.

21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-methyl acrylate copolymer resins. 177.1340... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1340 Ethylene-methyl acrylate copolymer resins. Ethylene-methyl acrylate copolymer resins may be safely used as articles or components of...

Self-assembly of graft polyurethanes having both crystallizable poly({epsilon}-caprolactone) blocks and soft poly(n-butyl acrylate) segments

Energy Technology Data Exchange (ETDEWEB)

Ibarboure, E.; Baron, A.; Papon, E. [Laboratoire de Chimie des Polymeres Organiques (LCPO), CNRS, Universite Bordeaux I. 16, Avenue Pey Berland, 33607, Pessac-Cedex (France); Rodriguez-Hernandez, J., E-mail: jrodriguez@enscpb.f [Laboratoire de Chimie des Polymeres Organiques (LCPO), CNRS, Universite Bordeaux I. 16, Avenue Pey Berland, 33607, Pessac-Cedex (France)

2009-04-02

We report the self-assembly behavior of graft polyurethanes combining in its structure soft lateral poly(n-butyl acrylate) (PnBuA) chains with rigid and crystallizable polycaprolactone (PCL) segments. Segmented polyurethanes microphase separated into high-glass transition temperature PCL hard and low-glass transition temperature PnBuA soft domains. The variation of the microstructure as a function of the hard segment content (ratio hard to soft segments) within the structure has been studied by using atomic force microscopy. Additionally, the crystallization mechanism appeared to be directly related to the properties of the substrates forming parallel lamellar structures on hydrophilic substrates and perpendicular lamellae with hydrophobic substrates.

Use of Acrylic Acid Sodium Acrylate Polymer to Maintain Cocoa Seed Viability

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Pudji Rahardjo

2010-08-01

Full Text Available The main problem of cocoa seed storage is moisture content of the seeds because cocoa seeds will germinate if cocoa seeds moisture content is high. The objective of this research is to maintain the cocoa seeds viability in storage using acrylic acid sodium acrylate polymer (AASAP. The function of AASAP is to absorb humidity in storage due to their ability to retain water and to prevent water loss. The experiment was conducted in a laboratory of Indonesian Coffee and Cocoa Research Institute and in Kaliwining Experimental Garden. This experiment was arranged by factorial randomized complete design, in wich AASAP dosages 0%; 0.1% (0.1 g/100 seeds; 0.2% (0.2 g/100 seeds, 0.3% (0.3 g/100 seeds, 0,4% (0,4g/100 seeds, combined with seeds storage period 1, 2, 3 and 4 weeks. The experiment used 3 replications and each repli cation used 100 seeds. Parameter of observation consisted of percentage of seeds germinated in storage, percentage of seeds infected by fungi in storage, seeds moisture content, percentage of seeds germination after storage, and early growth of cocoa seedlings. The results of the experiment showed that AASAP application with some dosages cocoa seeds storage cause to germinate in storage during 2 weeks. AASAP application with some dosages in cocoa seeds storage for 2 weeks would not result in infection by fungi and did not significantly affect seed germination after storage for 1, 2 and 4 weeks, and percentage of germination of cocoa seed after storage for 3 weeks decreased with increase dosage of AASAP. Higher dosage of AASAP would reduce early growth of cocoa seedling. Key words : Theobroma cacao, seed, acrylic acid sodium acrylate, seed storage, viabilty.

Ionizing radiation method for forming acrylic pressure sensitive adhesives and coated substrates

International Nuclear Information System (INIS)

Dowbenko, R.; Christenson, R.M.

1975-01-01

Pressure-sensitive adhesive having improved adhesive properties are formed by subjecting a mixture comprising a monomer selected from the group consisting of alkyl acrylates, hydroxyalkyl acrylates, alkoxyalkyl acrylates, cyanoalkyl acrylates, alkyl methacrylates, hydroxyalkyl methacrylates, alkoxyalkyl methacrylates, cyanoalkyl methacrylates, N-alkoxymethylacrylamides, and N-alkoxymethylmethacrylamides, and a homopolymer or copolymer selected from the group consisting of polymers of alkyl acrylates, hydroxyalkyl acrylates, alkoxyalkyl acrylates, cyanoalkyl acrylates, alkyl methacrylates, hydroxyalkyl methacrylates, alkoxyalkyl methacrylates, cyanoalkyl methacrylates, acrylamide, methacrylamide, N-(substituted alkyl) acrylamides, N-(substituted alkyl) methacrylamides, alkyl acrylamides, alkyl methacrylamides, and N-alkoxymethylacrylamides and N-alkoxymethylmethacrylamides to ionizing irradiation. The adhesive material finds utility as binding resins in laminates, coatings on substrates, and as film adhesives. (U.S.)

COMPARATIVE ANALYSIS OF WATER SORPTION BY DIFFERENT ACRYLIC MATERIALS

Directory of Open Access Journals (Sweden)

Milena Kostić

2014-06-01

Full Text Available Acrylic materials are used daily for the production of mobile dental restorations and orthodontic appliances. The presence of residual monomer, as a product of incomplete polymerisation of material, results in more porous structure of the material, which greatly reduces the mechanical and physical quality of the acrylic restorations and increases the absorption of liquids. The aim of this study was to examine the water absorption of different types of resin material. In the study it was assumed that the cold polymerized acrylates show a greater potential for absorbing fluid from the environment in relation to the hot polymerized acrylic. The study included two hot and two cold polymerized acrylates, and cold polymerized acrylate impregnated with aesthetic pearls. In order to determine the degree of water absorption, the mass of the samples was measured before and after one day, seven days and thirty days of immersion in a water bath of body temperature. The tested hot and cold polymerized acrylates after immersion in water bath showed standard values of water absorption. The degree of water absorption was not significantly influenced by the type and manner of polymerisation. Water absorption values were significantly higher after seven days and thirty days of water storage relative to the observational period of one day.

Synthesis and characterization of acrylated Parkia biglobosa ...

African Journals Online (AJOL)

The results revealed that acid functional acrylic copolymers containing maleic anhydride as a functional co-monomer can successfully be used to modify alkyd resins yielding acrylated resins with better drying, flexibility, scratch hardness, impact resistance and chemical resistance properties. However there exist optimum ...

Acute Retention of Urine Following Intraocular Surgery | Nwosu ...

African Journals Online (AJOL)

Hyperosmolar agents and carbonic anhydrase inhibitors are used to lower the intraocular pressure and thus minimize the chances of vitreous loss during intraocular surgery. However, these agents could precipitate urinary retention. This is a report on two elderly men who had perioperative acute urinary retention following ...

[Treatment of acrylate wastewater by electrocatalytic reduction process].

Science.gov (United States)

Yu, Li-Na; Song, Yu-Dong; Zhou, Yue-Xi; Zhu, Shu-Quan; Zheng, Sheng-Zhi; Ll, Si-Min

2011-10-01

High-concentration acrylate wastewater was treated by an electrocatalytic reduction process. The effects of the cation exchange membrane (CEM) and cathode materials on acrylate reduction were investigated. It indicated that the acrylate could be reduced to propionate acid efficiently by the electrocatalytic reduction process. The addition of CEM to separator with the cathode and anode could significantly improve current efficiency. The cathode materials had significant effect on the reduction of acrylate. The current efficiency by Pd/Nickel foam, was greater than 90%, while those by nickel foam, the carbon fibers and the stainless steel decreased successively. Toxicity of the wastewater decreased considerably and methane production rate in the biochemical methane potential (BMP) test increased greatly after the electrocatalytic reduction process.

Intraocular osseous metaplasia. A clinico-pathological study

OpenAIRE

Vemuganti Geeta; Honavar Santosh; Jalali Subhadra

2002-01-01

Purpose: To evaluate the clinico-pathologic features of intraocular osseous metaplasia. Methods: Pathology specimens of enucleated eyes submitted to the ophthalmic pathology service at a tertiary eye-care referral center between January 1995 and June 1999 were studied for intraocular osseous metaplasia. Specific histopathologic features noted in specimens with osseous metaplasia were the presence of retinal detachment, gliosis, retinal pigment epithelial hyperplasia, drusen, epiretinal membra...

Resultados da troca de lente intra-ocular de hidrogel opacificada

Directory of Open Access Journals (Sweden)

Salera Cristina Moreira

2004-01-01

Full Text Available OBJETIVO: Avaliar os resultados da explantação e substituição das lentes intra-oculares (LIO de hidrogel opacificadas. MÉTODOS: Foram analisados retrospectivamente os prontuários de 12 pacientes (15 olhos submetidos à explantação e substituição das lentes intra-oculares de hidrogel opacificadas. RESULTADOS: A opacificação das lentes intra-oculares de hidrogel causou perdas de linhas de visão em 13 olhos (86,7%. A troca das lentes intra-oculares opacificadas promoveu o ganho de linhas de visão em 11 olhos (73,3%. As complicações peroperatórias ocorreram em três olhos (20% e foram as seguintes: perda de óleo de silicone, ruptura total de zônula com perda do saco capsular e ruptura parcial de zônula. Durante a explantação das lentes intra-oculares foi necessária a realização de incisões relaxantes na borda da capsulorrexe anterior em três olhos (20% e em dois olhos (13,3% os hápticos foram cortados sendo retirada somente a zona óptica das lentes intra-oculares. CONCLUSÃO: A cirurgia para explantação e substituição das lentes intra-oculares opacificadas mostrou-se eficaz naqueles pacientes com perdas de linhas de visão (p > 0,05.

Waterborne hyperbranched alkyd-acrylic resin obtained by mini emulsion polymerization

Energy Technology Data Exchange (ETDEWEB)

Murillo, Edwin, E-mail: edwinalbertomurillo@gmail.com [Grupo de Investigacion en Materiales Polimericos (GIMAPOL), Universidad Francisco de Paula Santander, San Jose de Cucuta (Colombia); Lopez, Betty [Grupo de Investigacion en Ciencia de los Materiales, Universidad de Antioquia, Calle, Medellin (Colombia)

2016-10-15

Four waterborne hyper branched alkyd-acrylic resins (HBRAA) were synthesized by mini emulsion polymerization from a hyper branched alkyd resin (HBR), methyl methacrylate (MMA), butyl acrylate (BA) and acrylic acid (AA), by using benzoyl peroxide (BPO) and ammonium persulfate (AP) as initiators. The reaction between HBR and acrylic monomers was evidenced by differential scanning calorimetric (DSC), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The conversion percentage, glass transition temperature (T{sub g}), content of acrylic polymer (determined by soxhlet extraction) and molecular weight increased with the content of acrylic monomers used in the synthesis. The main structure formed during the synthesis was the HBRAA. The analysis by dynamic light scattering (DLS) showed that the particle size distribution of HBRAA2, HBRAA3 and HBRAA4 resins were mainly mono modal. The film properties (gloss, flexibility, adhesion and drying time) of the HBRAA were good. (author)

Biocompatibility of acrylic resin after being soaked in sodium hypochlorite

Directory of Open Access Journals (Sweden)

Nike Hendrijatini

2009-06-01

Full Text Available Background: Acrylic resin as basic material for denture will stay on oral mucosa for a very long time. The polymerization of acrylic resin can be performed by conventional method and microwave, both produce different residual monomer at different toxicity. Acrylic resin can absorb solution, porous and possibly absorb disinfectantt as well, that may have toxic reaction with the tissue. Sodium Hypochlorite as removable denture disinfectant can be expected to be biocompatible to human body. The problem is how biocompatible acrylic resin which has been processed by conventional method and microwave method after being soaked in sodium hypochlorite solution. Purpose: The aim of this study was to understand in vitro biocompatibility of acrylic resin which has polimerated by conventional method and microwave after being soaked in sodium hypochlorite using tissue culture. Methods: Four groups of acrylic resin plate were produced, the first group was acrylic resin plate with microwave polymeration and soaked in sodium hypochlorite, the second group was acrylic resin plate with microwave polymeration but not soaked, the thirdwas one with conventional method and soaked and the last group was one with conventional method but not soaked, and in 1 control group. Each group consists of 7 plates. Biocompatibility test was performed in-vitro on each material using fibroblast tissue culture (BHK-21 cell-line. Result: The percentage between living cells and dead cells from materials which was given acrylic plate was wounted. The data was analyzed statistically with T test. Conclusion: The average value of living cells is higher in acrylic resin poimerization using microwave method compared to conventional method, in both soaked and non soaked (by sodium hypochlorite group. This means that sodium hypochlorite 0.5% was biocompatible to the mouth mucosa as removable denture disinfectant for 10 minutes soaking and washing afterwards.

Importance of intraocular pressure in glaucoma

Science.gov (United States)

Joos, Karen M.

1999-06-01

Glaucoma results in permanent vision loss and affects the peripheral vision initially. It is presented in 22.5 million people worldwide and is the 3rd cause of blindness. Present tonometers are not ideal for intraocular pressure measurements in all eyes. Of concern, PRK and LASIK may result in lower intraocular pressure readings. A challenges now exists for the development of a tonometer which can easily compensate for corneas with many parameters to avoid a future increase in normal-tension glaucoma or glaucoma which is advanced.

Solid intraocular xanthogranuloma in three Miniature Schnauzer dogs.

Science.gov (United States)

Zarfoss, Mitzi K; Dubielzig, Richard R

2007-01-01

Macrophages that contain abundant intracytoplasmic lipid are called 'foam cells'. In four canine globes submitted to the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW), foam cells formed a solid intraocular mass. The purpose of this study was to describe the histopathologic findings in these cases. The electronic COPLOW database (1993-2006) was searched for the diagnosis of 'foam cell tumor'. Clinical history, gross pathology and histopathology (5-micron sections, hematoxylin and eosin and Alcian blue periodic acid Schiff) were reviewed in all cases. Cases were included if the globe was grossly filled by a solid mass and if all intraocular structures were effaced by lipid-laden foam cell macrophages admixed with birefringent, Alcian blue-positive crystals oriented in stellate patterns. All three patients (four globes) satisfying the selection criteria were Miniature Schnauzers. In all cases the clinical history included diabetes mellitus, hyperlipidemia and chronic bilateral uveitis that was interpreted to be lens-induced. All globes were enucleated because of glaucoma. The term solid intraocular xanthogranuloma was used to describe these cases because the intraocular contents were effaced by a solid mass of foam cells and birefringent crystals. The cases in this report suggest that diabetic Miniature Schnauzers with hyperlipidemia are at risk for lipid and macrophage-rich uveitis, which may in some cases form a solid inflammatory intraocular mass, precipitate glaucoma, and lead to enucleation.

Investigation of Acrylic Acid at High Pressure using Neutron Diffraction

DEFF Research Database (Denmark)

Johnston, Blair F.; Marshall, William G.; Parsons, Simon

2014-01-01

This article details the exploration of perdeuterated acrylic acid at high pressure using neutron diffraction. The structural changes that occur in acrylic acid-d4 are followed via diffraction and rationalised using the Pixel method. Acrylic acid undergoes a reconstructive phase transition to a new...

Chemo-enzymatic synthesis route to poly(glucosyl-acrylates) using glucosidase from almonds

NARCIS (Netherlands)

Kloosterman, Wouter M. J.; Roest, Steven; Priatna, Siti R.; Stavila, Erythrina; Loos, Katja

2014-01-01

Novel types of glucosyl-acrylate monomers are obtained by beta-glucosidase from almond catalyzed glycosidation reaction. The saccharide-acrylate monomers were synthesized by reaction of D-glucose with hydroxyl functional acrylates: 2-hydroxyethyl acrylate (2-HEA), 2-hydroxyethyl methacrylate

Poly(alkyl acrylate) nonparticles

International Nuclear Information System (INIS)

Kreuter, J.

1985-01-01

This study deals with the preparation of poly(alkyl acrylic) and poly(alkyl cyanocrylic) nanoparticles. Nonoparticles are solid colloidal particles, consisting of macromolecular materials in which drugs or biologically active materials are dissolved, entrapped, and encapsulated, and/or to which the active substance is adsorbed or attached. Poly(alkyl acrylic) nanoparticles are much more slowly biodegradable than poly(alkyl cyanoacrylate) nanoparticles, and are thus more suitable for drug delivery purposes. Poly(methyl methacrylate) is the material of choice for the use of nanoparticles as an adjuvant for vaccines and are produced by emulsifier-free polymerization in aqueous media. The polymerization, which can be initiated with gamma rays or with potassium peroxodisulfate, is described

Methacrylate and acrylate allergy in dental personnel.

Science.gov (United States)

Aalto-Korte, Kristiina; Alanko, Kristiina; Kuuliala, Outi; Jolanki, Riitta

2007-11-01

Methacrylates are important allergens in dentistry. The study aimed to analyse patch test reactivity to 36 acrylic monomers in dental personnel in relation to exposure. We reviewed the test files at the Finnish Institute of Occupational Health from 1994 to 2006 for allergic reactions to acrylic monomers in dental personnel and analysed the clinical records of the sensitized patients. 32 patients had allergic reactions to acrylic monomers: 15 dental nurses, 9 dentists, and 8 dental technicians. The dentists and dental nurses were most commonly exposed to 2-hydroxyethyl methacrylate (2-HEMA), triethyleneglycol dimethacrylate (TREGDMA), and 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (bis-GMA). 8 dentists and 12 dental nurses were allergic to 2-HEMA. The remaining dentist was positive to bis-GMA and other epoxy acrylates. The remaining 3 dental nurses reacted to diethyleneglycol diacrylate (DEGDA) or triethyleneglycol diacrylate (TREGDA), but not to monofunctional and multifunctional methacrylates. Our dental technicians were mainly exposed and sensitized to methyl methacrylate (MMA) and ethyleneglycol dimethacrylate (EGDMA). 1 technician reacted only to 2-HEMA, and another to ethyl methacrylate (EMA) and ethyl acrylate (EA). 2-HEMA was the most important allergen in dentists and dental nurses, and MMA and EGDMA in dental technicians. Reactions to bis-GMA, DEGDA, TREGDA, EMA and EA were relevant in some patients.

The Increase of Intra-Abdominal Pressure Can Affect Intraocular Pressure

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Ilhan Ece

2015-01-01

Full Text Available Objective. This study aims to explore the usage of intraocular pressure measurements as the early indicator of the increase in intra-abdominal pressure. Methods. In this prospective study, 40 patients undergoing elective surgery were included. Patients were divided into four groups of 10 patients. The control group (Group C was not subjected to laparoscopic intervention. Laparoscopic surgery was, respectively, performed with an intra-abdominal pressure of 9, 12, and 15 mmHg in Groups L (low, M (medium, and H (high pressure. Intraocular pressure was measured binocularly in each patient at three different times (before, during, and end of surgery using a contact tonometer. Results. Patients’ gender, age, body mass index (BMI, American Society of Anesthesiology (ASA class, and operative times were not different among the groups. No complications occurred with either the surgery or measurement of intraocular pressure. Intubation was associated with a severe rise in IOP (P<0.05. An increase in intraocular pressure was seen in groups M and H (P<0.05. Conclusion. Intraocular pressure was increased in the groups with an intra-abdominal pressure of 12 mmHg or more. Measuring the intraocular pressure might be a useful method to estimate the intra-abdominal pressure. This trial is registered with NCT02319213.

Resultados de implante de lente intraocular en niños Results of intraocular lens implantation in children

Directory of Open Access Journals (Sweden)

Nashelly I. Mejía Cruz

2007-12-01

Full Text Available En este estudio se describen los resultados obtenidos del implante de lente intraocular en niños, quienes acudieron al servicio de Oftalmología Pediátrica de Instituto Cubano de oftalmología “Ramón Pando Ferrer” con el diagnóstico de catarata de diversas etiologías, en período comprendido entre abril del 2002 al 2005 cuyo seguimiento fue durante un año. En nuestro universo de estudio se determinan algunos parámetros como la edad del paciente, etiología de las cataratas, agudeza visual, defecto refractivo preoperatorio y posoperatorio. Se identificó el poder dióptrico del lente intraocular más frecuente, la presencia de complicaciones durante la cirugía y después de esta. Se evaluaron finalmente, los pacientes que requerían de tratamiento adicional como la capsulotomía con láser o membranectomía quirúrgica. El implante del lente intraocular a temprana edad se relacionó con buenos resultados quirúrgicos: mejoría de la agudeza visual corregida, presentándose el astigmatismo como el error refractivo más frecuente. La complicación transoperatorio y postoperatoria más frecuente fue la membrana inflamatoria, mientras que la complicación posoperatoria más frecuente fue la opacidad de la cápsula posterior.This paper described the results of the intraocular lens implantation performed in children, who had been seen at the Pediatric Ophthalmologic Service of " Ramon Pando Ferrer " Cuban Institute of Ophthalmology and had been diagnosed as having cataract of various etiologies, from April 2002 to April 2005. They were all followed-up for a year. Some parameters like the patient’s age, the etiology of cataract, visual acuity, pre-operative and post-operative refractive defect were considered in our study. The dioptric power of the most common intraocular lens and the most frequent complications during and after surgery were identified. The patients requiring additional treatment such as laser capsulotomy and surgical

Antimicrobial activity of poly(acrylic acid) block copolymers

Energy Technology Data Exchange (ETDEWEB)

Gratzl, Günther, E-mail: guenther.gratzl@jku.at [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Paulik, Christian [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Hild, Sabine [Johannes Kepler University Linz, Institute of Polymer Science, Altenberger Str. 69, 4040 Linz (Austria); Guggenbichler, Josef P.; Lackner, Maximilian [AMiSTec GmbH and Co. KG, Leitweg 13, 6345 Kössen, Tirol (Austria)

2014-05-01

The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid–base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure. - Highlights: • Acrylic acid diblock copolymers are antimicrobially active. • The antimicrobial activity depends on the acrylic acid content in the copolymer. • No salts, metals or other antimicrobial agents are needed.

Antimicrobial activity of poly(acrylic acid) block copolymers

International Nuclear Information System (INIS)

Gratzl, Günther; Paulik, Christian; Hild, Sabine; Guggenbichler, Josef P.; Lackner, Maximilian

2014-01-01

The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid–base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure. - Highlights: • Acrylic acid diblock copolymers are antimicrobially active. • The antimicrobial activity depends on the acrylic acid content in the copolymer. • No salts, metals or other antimicrobial agents are needed

New acrylic resin composite with improved thermal diffusivity.

Science.gov (United States)

Messersmith, P B; Obrez, A; Lindberg, S

1998-03-01

Studies have shown that physical characteristics of denture base materials may affect patient acceptance of denture prostheses by altering sensory experience of food during mastication. Thermal diffusivity is one material property that has been cited as being important in determining gustatory response, with denture base acrylic resins having low thermal diffusivity compared with denture base metal alloys. This study prepared and characterized experimental acrylic resin composite material with increased thermal diffusivity. Sapphire (Al2O3) whiskers were added to conventional denture base acrylic resin during processing to achieve loadings of 9.35% and 15% by volume. Cylindrical test specimens containing an embedded thermocouple were used to determine thermal diffusivity over a physiologic temperature range (0 degree to 70 degrees C). Thermal diffusivities of the sapphire containing composites were found to be significantly higher than the unmodified acrylic resin. Thermal diffusivity was found to increase in proportion to the volume percentage of sapphire filler, which suggested that the high aspect ratio ceramic particles formed a pathway for heat conduction through the insulating polymer matrix. The thermal diffusivity of denture base acrylic resin was increased by the addition of thermally conducting sapphire whiskers.

UV-crosslinkable photoreactive self-adhesive hydrogels based on acrylics

Directory of Open Access Journals (Sweden)

Czech Zbigniew

2016-06-01

Full Text Available Hydrogels are a unique class of macromolecular networks that can hold a large fraction of an aqueous solvent within their structure. They are suitable for biomedical area including controlled drug delivery and for technical applications as self-adhesive materials for bonding of wet surfaces. This paper describes photoreactive self-adhesive hydrogels based on acrylics crosslinked using UV radiation. They are prepared in ethyl acetate through radical polymerization of monomers mixture containing 2-ethylhexyl acrylate (2-EHA, butyl acrylate (BA, acrylic acid (AA and copolymerizable photoinitiator 4-acryloyloxy benzophenone (ABP at presence of radical starter 2.2’-azobis-diisobutyronitrile AIBN. The synthesized acrylic copolymers were determined by viscosity and GPC analysis and later modified using ethoxylated amines. 4-acryloyloxy benzophenone (ABP was used as crosslinking monomer. After UV crosslinking the properties of these novel synthesized hydrogels, such as tack, peel adhesion, shears strength, elongation and water adsorption were also studied.

Artificial saliva effect on toxic substances release from acrylic resins

Directory of Open Access Journals (Sweden)

Kostić Milena

2015-01-01

Full Text Available Background/Aim. Acrylic-based resins are intensively used in dentistry practice as restorative or denture-base materials. The purpose of this study was to analyze the surface structure of denture base resins and the amount of released potentially toxic substances (PTS immediately upon polymerization and incubation in different types of artificial saliva. Methods. Storage of acrylic samples in two models of artificial saliva were performed in a water bath at the temperature of 37 ± 1°C. Analysis of the surface structure of samples was carried out using scanning electronic microscopy analysis immediately after polymerization and after the 30-day incubation. The amounts of PTS per day, week and month extracts were measured using high-pressure liquid chromatography. Results. Surface design and amount of PTS in acrylic materials were different and depended on the types and duration of polymerization. The surfaces of tested acrylates became flatter after immersing in solutions of artificial saliva. The degree of acrylic materials release was not dependent on the applied model of artificial saliva. Conclusion. In order to improve biological features of acrylic resin materials, it was recommended that dentures lined with soft or hard coldpolymerized acrylates should be kept at least 1 to 7 days in water before being given to a patient. So, as to reach high degree of biocompatibility preparation of prosthetic restorations from heat-polymerized acrylate was unnecessary. [Projekat Ministarstva nauke Republike Srbije, br. 41017

Ca (OH)2Nanoparticles Based on Acrylic Copolymers for the consolidation and protection of Ancient Egypt Calcareous Stone Monuments

Science.gov (United States)

Al-Dosari, Mohammad A.; Darwish, Sawsan S.; Adam, Mahmoud A.; Elmarzugi, Nagib A.; Al-Mouallimi, Nadia; Ahmed, Sayed M.

2017-04-01

The deterioration of calcareous stones materials used in artistic/architectural field is one of the most serious problems facing conservation today. The aim of this study was to evaluate the effectiveness of nanosized particles of calcium hydroxide (slaked lime) as a consolidation and protection material dispersed in acrylic copolymer, poly ethylmethacrylate/methylacrylate (70:30) (Poly (EMA/MA), for calcareous stone monuments and painted surfaces affected by different kinds of decay. The synthesis process of Ca (OH)2 nanoparticles/polymer nanocomposites have been prepared by in situ emulsion polymerization system. The prepared nanocomposite containing 5% of Ca (OH)2 nanoparticles showed obvious transparency features and represent nanocomposites coating technology with hydrophobic, consolidating and well protection properties.

Ca (OH)2Nanoparticles Based on Acrylic Copolymers for the consolidation and protection of Ancient Egypt Calcareous Stone Monuments

International Nuclear Information System (INIS)

Al-Dosari, Mohammad A.; Ahmed, Sayed M.; Darwish, Sawsan S.; Adam, Mahmoud A.; Elmarzugi, Nagib A.; Al-Mouallimi, Nadia

2017-01-01

The deterioration of calcareous stones materials used in artistic/architectural field is one of the most serious problems facing conservation today. The aim of this study was to evaluate the effectiveness of nanosized particles of calcium hydroxide (slaked lime) as a consolidation and protection material dispersed in acrylic copolymer, poly ethylmethacrylate/methylacrylate (70:30) (Poly (EMA/MA), for calcareous stone monuments and painted surfaces affected by different kinds of decay. The synthesis process of Ca (OH) 2 nanoparticles/polymer nanocomposites have been prepared by in situ emulsion polymerization system. The prepared nanocomposite containing 5% of Ca (OH) 2 nanoparticles showed obvious transparency features and represent nanocomposites coating technology with hydrophobic, consolidating and well protection properties. (paper)

78 FR 55644 - Styrene, Copolymers with Acrylic Acid and/or Methacrylic Acid; Tolerance Exemption

Science.gov (United States)

2013-09-11

..., 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and/or hydroxyethyl acrylate; and its sodium, potassium, ammonium..., hydroxypropyl acrylate, hydroxyethyl methacrylate, and/or hydroxyethyl acrylate; and its sodium, potassium...

The development of epoxidised palm oil acrylate (EPOLA) and its applications

Energy Technology Data Exchange (ETDEWEB)

Mahmood, Mohd Hilmi [Nuclear Energy Unit, Bangi, Selangor (Malaysia)

1994-12-31

The topics are discussed briefly. Acrylated palm oil is prepared through acrylation process, whereby, acrylic acid is introduced into oxirane group of the EPOP (epoxidised palm oil products), EPOLA (epoxidised palm oil products acrylate) was found curable when subjected to UV (ultrviolet) light giving soft coatings. EPOLA is used as radiation curable filler/sealer, radiation curable pressure sensitive adhesives and satisfactorily be coated on wood substrates (rubberwood parquets).

The development of epoxidised palm oil acrylate (EPOLA) and its applications

International Nuclear Information System (INIS)

Mohd Hilmi Mahmood

1993-01-01

The topics are discussed briefly. Acrylated palm oil is prepared through acrylation process, whereby, acrylic acid is introduced into oxirane group of the EPOP (epoxidised palm oil products), EPOLA (epoxidised palm oil products acrylate) was found curable when subjected to UV (ultrviolet) light giving soft coatings. EPOLA is used as radiation curable filler/sealer, radiation curable pressure sensitive adhesives and satisfactorily be coated on wood substrates (rubberwood parquets)

Photochemistry of acrylates at 222 nm

International Nuclear Information System (INIS)

Knolle, Wolfgang; Naumov, Sergej; Madani, Mohamed; Sonntag, Clemens von

2005-01-01

Excimer lamps as monochromatic UV sources with an intense short-wavelength emission (especially KrCl * , 222 nm) allow a photoinitiator-free initiation of the acrylate polymerisation. Laser photolysis (KrCl * excimer laser, pulse width 20 ns, up to 5 mJ per pulse) gives rise to similar transient spectra (λ max ∼ 280 nm) for all acrylates studied. As the rather unspecific spectra do not allow conclusions as to the main reaction channel, a product study has been performed by GC-MS following steady-state photolysis of acrylate solutions in acetonitrile, methanol and n-hexane. Somewhat unexpected, α-cleavage seems to be a main reaction channel, and quantum chemical calculations show that such a reaction can occur from either the excited singlet state or the unrelaxed triplet state, but not from the relaxed triplet state that is observed spectroscopically. A reaction scheme accounting for the observed products is presented

The effect of intraocular gas and fluid volumes on intraocular pressure.

Science.gov (United States)

Simone, J N; Whitacre, M M

1990-02-01

Large increases in the intraocular pressure (IOP) of postoperative gas-containing eyes may require the removal of gas or fluid to reduce the IOP to the normal range. Application of the ideal gas law to Friedenwald's equation provides a mathematical model of the relationship between IOP, intraocular gas and fluid volumes, and the coefficient of scleral rigidity. This mathematic model shows that removal of a given volume of gas or fluid produces an identical decrease in IOP and that the more gas an eye contains, the greater the volume reduction necessary to reduce the pressure. Application of the model shows that the effective coefficient of scleral rigidity is low (mean K, 0.0021) in eyes with elevated IOP that have undergone vitrectomy and retinal cryopexy and very low (mean K, 0.0013) in eyes with elevated IOP that have undergone placement of a scleral buckle and band. By using the appropriate mean coefficient of rigidity, the volume of material to be aspirated to produce a given decrease in IOP can be predicted with clinically useful accuracy.

Commercial air travel after intraocular gas injection.

Science.gov (United States)

Houston, Stephen; Graf, Jürgen; Sharkey, James

2012-08-01

Passengers with intraocular gas are at risk of profound visual loss when exposed to reduced absolute pressure within the cabin of a typical commercial airliner. Information provided on the websites of the world's 10 largest airlines offer a considerable range of opinion as to when it might be safe to fly after gas injection. Physicians responsible for clearing pseassengers as 'fit to fly' should be aware modern retinal surgical techniques increasingly employ long-acting gases as vitreous substitutes. The kinetics of long-acting intraocular gases must be considered when deciding how long after surgery it is safe to travel. It is standard practice to advise passengers not to fly in aircraft until the gas is fully resorbed. To achieve this, it may be necessary to delay travel for approximately 2 wk after intraocular injection of sulfur hexafluoride (SF6) and for 6 wk after injection of perfluoropropane (C3F8).

Synthesis and characterization of acrylated Parkia biglobosa medium oil alkyds

Directory of Open Access Journals (Sweden)

E.T. Akintayo

2004-12-01

Full Text Available Acrylated Parkia biglobosa medium oil alkyd prepared by the reaction between an acid containing acrylic copolymer and a monoglyceride followed by the addition of polyol and dibasic acid has been investigated for improved properties. The results revealed that acid functional acrylic copolymers containing maleic anhydride as a functional co-monomer can successfully be used to modify alkyd resins yielding acrylated resins with better drying, flexibility, scratch hardness, impact resistance and chemical resistance properties. However there exist optimum levels for modification of alkyds with such copolymers beyond which certain film properties are adversely affected.

All-acrylic superelastomers: facile synthesis and exceptional mechanical behavior

Energy Technology Data Exchange (ETDEWEB)

Lu, Wei; Goodwin, Andrew; Wang, Yangyang; Yin, Panchao; Wang, Weiyu; Zhu, Jiahua; Wu, Ting; Lu, Xinyi; Hu, Bin; Hong, Kunlun; Kang, Nam-Goo; Mays, Jimmy (Tennessee-K); (ORNL)

2018-01-01

All-acrylic multigraft copolymers made by a facile synthesis procedure exhibit elongation at break >1700% and strain recovery behavior far exceeding those of commercial acrylic and styrenic triblock copolymers.

Intraocular Inflammation Associated with Ocular Toxoplasmosis : Relationships at Initial Examination

NARCIS (Netherlands)

Dodds, Emilio M.; Holland, Gary N.; Stanford, Miles R.; Yu, Fei; Siu, Willie O.; Shah, Kayur H.; Loon, Ninette Ten Dam-Van; Muccioli, Cristina; Hovakimyan, Anna; Barisani-Asenbauer, Talin

2008-01-01

PURPOSE: To describe characteristics of intraocular inflammation in eyes with active ocular toxoplasmosis and to identify relationships between signs of inflammation, complications (including elevated intraocular pressure [IOP]), other disease features, and host characteristics. DESIGN: Multicenter,

Thermogravimetric analysis of the polymer acrylate-vinyl ether mixture cured by radiation

International Nuclear Information System (INIS)

Danu, Sugiarto

1998-01-01

An experiment on thermal stability of the polymer acrylate-vinyl ether mixture cured by radiation have been done using thermogravimetric analysis. Three kinds of acrylic oligomers i.e., epoxy acrylate, urethane acrylate, and polypropylene glycol diacrylate, and vinyl ether monomers i.e., triethylene glycol divinyl ether (DVE-3), 1,4-cyclohexane dimethanol divinyl ether (CHVE), and butanediol monovinyl ether (HBVE) were used in the experiment. Reaction was taken via radical and cationic polymerisation. In case of cationic polymerisation, diphenyliodonium hexafluorophosphate fotoinisiator was used in the formulation. Thermogravimetric analysis was conducted in a nitrogen atmosphere at a flow rate of 40 ml/minute with a constant heating rate 10 o C and evaluation range were done from 25 to 500 o C. The results of thermogravimetric analysis showed that acrylate and DVE-3 mixture produced the polymer films with higher thermal stability than the mixture of acrylate with CHVE or HBVE. The composition of acrylate-vinyl ether mixture and degree of unsaturation of vinyl ether monomers influenced the thermal stability of polymer. The mixture of epoxy acrylate-vinyl ether and polypropylene glycol diacrylate-vinyl ether have 1 initial decomposition temperature whereas the urethane acrylate-vinyl ether mixture has 2 initial decomposition temperatures. (authors)

Long-Chain Diacrylate Crosslinkers and Use of PEG Crosslinks in Poly(potassium acrylate-acrylic acid)/Kaolin Composite Superabsorbents

OpenAIRE

Koroush Kabiri; Siavash Nafisi; Mohammad jalaledin Zohuriaan-Mehr; Ali Akbar Yousefi

2013-01-01

Long-chain diacrylate crosslinkers based on linear α,ω-diols were synthesized and characterized using FTIR and 1H NMR spectroscopy. The highest reaction yield (99.5%) was due to polyethylene glycol diacrylate 1000 (PEGDA-1000). Then, kaolin-containing poly(potassium acrylate-acrylic acid) superabsorbent composites and kaolin-free counterparts were synthesized using PEGDA-1000.The effect of the crosslinker concentration on swelling, rheological and thermo-mechanical properties was investigated...

Toric Intraocular Lens Outcomes in Patients With Glaucoma.

Science.gov (United States)

Brown, Reay H; Zhong, Le; Bozeman, Caroline W; Lynch, Mary G

2015-06-01

To report the outcomes of toric intraocular lens implantation in patients with glaucoma and corneal astigmatism. One hundred twenty-six eyes of 87 patients with glaucoma and corneal astigmatism that underwent cataract surgery with an AcrySof toric intraocular lens (Alcon Laboratories, Inc., Fort Worth, TX) implant were selected for this single-center, retrospective case series. Corrected distance visual acuity, intraocular pressure, and refractive astigmatism were measured in each eye preoperatively and postoperatively. Uncorrected distance visual acuity and toric alignment were measured postoperatively. The uncorrected distance visual acuity was 0.04 ± 0.08 logMAR (20/22 Snellen) for all eyes. Ninety-eight percent of all eyes achieved an uncorrected distance visual acuity of 20/40 or better, with 76% achieving 20/25 or better and 47% achieving 20/20. The corrected distance visual acuity for all eyes was 0.01 ± 0.03 logMAR (20/20.5 Snellen) postoperatively. The refractive cylinder improved from 1.47 ± 1.10 diopters preoperatively to 0.31 ± 0.37 diopters postoperatively. The residual refractive cylinder was 1.00 diopter or less in 97% of eyes, 0.75 diopters or less in 90% of eyes, and 0.50 diopters or less in 83% of eyes. Mean misalignment was 4.4° ± 5.1°. Intraocular pressure decreased by a mean of 2.3 ± 3.3 mm Hg following the surgery. Toric intraocular lenses can reliably reduce astigmatism and improve uncorrected vision in eyes with cataract and glaucoma. Copyright 2015, SLACK Incorporated.

Injectable biocompatible and biodegradable pH-responsive hollow particle gels containing poly(acrylic acid): the effect of copolymer composition on gel properties.

Science.gov (United States)

Halacheva, Silvia S; Adlam, Daman J; Hendow, Eseelle K; Freemont, Tony J; Hoyland, Judith; Saunders, Brian R

2014-05-12

The potential of various pH-responsive alkyl (meth)acrylate ester- and (meth)acrylic acid-based copolymers, including poly(methyl methacrylate-co-acrylic acid) (PMMA-AA) and poly(n-butyl acrylate-co-methacrylic acid) (PBA-MAA), to form pH-sensitive biocompatible and biodegradable hollow particle gel scaffolds for use in non-load-bearing soft tissue regeneration have been explored. The optimal copolymer design criteria for preparation of these materials have been established. Physical gels which are both pH- and redox-sensitive were formed only from PMMA-AA copolymers. MMA is the optimal hydrophobic monomer, whereas the use of various COOH-containing monomers, e.g., MAA and AA, will always induce a pH-triggered physical gelation. The PMMA-AA gels were prepared at physiological pH range from concentrated dispersions of swollen, hollow, polymer-based particles cross-linked with either cystamine (CYS) or 3,3'-dithiodipropionic acid dihydrazide (DTP). A linear relationship between particle swelling ratios, gel elasticity, and ductility was observed. The PMMA-AA gels with lower AA contents feature lower swelling ratios, mechanical strengths, and ductilities. Increasing the swelling ratio (e.g., through increasing AA content) decreased the intraparticle elasticity; however, intershell contact and gel elasticity were found to increase. The mechanical properties and performance of the gels were tuneable upon varying the copolymers' compositions and the structure of the cross-linker. Compared to PMMA-AA/CYS, the PMMA-AA/DTP gels were more elastic and ductile. The biodegradability and cytotoxicity of the new hollow particle gels were tested for the first time and related to their composition, mechanical properties, and morphology. The new PMMA-AA/CYS and PMMA-AA/DTP gels have shown good biocompatibility, biodegradability, strength, and interconnected porosity and therefore have good potential as a tissue repair agent.

Effect of plasma colloid osmotic pressure on intraocular pressure during haemodialysis

OpenAIRE

Tokuyama, T.; Ikeda, T.; Sato, K.

1998-01-01

BACKGROUND—In a previous case report, it was shown that an increase in plasma colloid osmotic pressure induced by the removal of fluid during haemodialysis was instrumental in decreasing intraocular pressure. The relation between changes in intraocular pressure, plasma osmolarity, plasma colloid osmotic pressure, and body weight before and after haemodialysis is evaluated.
METHODS—Intraocular pressure, plasma osmolarity, plasma colloid osmotic pressure, and body weight were evaluated before a...

Studies on Development of Polymeric Materials Using Gamma Irradiation for Contact and Intraocular Lenses

Directory of Open Access Journals (Sweden)

Pranshu Chhabra

2009-01-01

Full Text Available For the development of materials for contact lenses and intraocular lenses, the selection criteria is based on the (i capacity to absorb and retain water, (ii hydrophilicity and hydrophobicity, (iii refractive index and (iv hardness besides the other essential properties. Various monomers are being studied to develop suitable materials for such applications. Selection of suitable monomers that can be converted into optical materials of desired characteristics is the most essential step. In the present paper, an attempt has been made to develop suitable optical polymers based on 2-hydroxy ethyl methacrylate (HEMA, N-vinyl pyrrolidone (NVP, methyl methacrylate (MMA, methacrylic acid (MAA, and styrene. Compositions were prepared in such a way that polymers of varying hydrophilicity or hydrophobicity could be obtained keeping HEMA as the base (main monomer. For polymerization, gamma irradiation (Co-60 as a source was used. The results of the study showed that: (i an increase in NVP and MAA content brought in an increase in hydrophilicity of polymerized HEMA (pHEMA, while the addition of styrene and MMA decreased hydrophilicity of polymerized HEMA (pHEMA, (ii polymers for contact lenses with water retention capacity as high as >50 wt.% and as low as <10 wt% with varying content of suitable comonomers can be designed, (iii polymeric materials for contact lenses can be made by using radiation processing such as Co-60 and (iv a dose of 40 kGy was found to be ideal for purpose.

Severe pigment dispersion after iris-claw phakic intraocular lens implantation.

Science.gov (United States)

Galvis, Virgilio; Carreño, Néstor I; Tello, Alejandro; Laiton, Andrea N

2017-12-01

A 23-year-old female patient presented 3 months after the implantation of an Artisan® phakic intraocular lens with a severe depigmentation of the iris and peripheral anterior synechiae. Explantation of the intraocular lens and goniosynechialysis were performed. Eleven months after the explantation appearance of the iris significantly improved. There was no loss of lines of corrected distance visual acuity. Severe pigment dispersion after the implantation of an Artisan® phakic intraocular lens may happen and may require explantation of the lens. Iris depigmentation may improve with time.

Severe pigment dispersion after iris-claw phakic intraocular lens implantation

Directory of Open Access Journals (Sweden)

Virgilio Galvis

2017-01-01

Full Text Available A 23-year-old female patient presented 3 months after the implantation of an Artisan® phakic intraocular lens with a severe depigmentation of the iris and peripheral anterior synechiae. Explantation of the intraocular lens and goniosynechialysis were performed. Eleven months after the explantation appearance of the iris significantly improved. There was no loss of lines of corrected distance visual acuity. Severe pigment dispersion after the implantation of an Artisan® phakic intraocular lens may happen and may require explantation of the lens. Iris depigmentation may improve with time.

Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate

Energy Technology Data Exchange (ETDEWEB)

Binder, Thomas [Archer Daniels Midland Company, Decatur, IL (United States); Erpelding, Michael [Archer Daniels Midland Company, Decatur, IL (United States); Schmid, Josef [Archer Daniels Midland Company, Decatur, IL (United States); Chin, Andrew [Archer Daniels Midland Company, Decatur, IL (United States); Sammons, Rhea [Archer Daniels Midland Company, Decatur, IL (United States); Rockafellow, Erin [Archer Daniels Midland Company, Decatur, IL (United States)

2015-04-10

Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate. The purpose of Archer Daniels Midlands Integrated Biorefinery (IBR) was to demonstrate a modified acetosolv process on corn stover. It would show the fractionation of crop residue to distinct fractions of cellulose, hemicellulose, and lignin. The cellulose and hemicellulose fractions would be further converted to ethanol as the primary product and a fraction of the sugars would be catalytically converted to acrylic acid, with butyl acrylate the final product. These primary steps have been demonstrated.

The sensitizing capacity of multifunctional acrylates in the guinea pig.

Science.gov (United States)

Björkner, B

1984-10-01

The multifunctional acrylates used in ultraviolet (UV) curable resins act as cross-linkers and "diluents". They are usually based on di(meth)acrylate esters of dialcohols or tri- and tetra-acrylate esters of polyalcohols. In UV-curable coatings, the most commonly used are pentaerythritol triacrylate (PETA), trimethylolpropane triacrylate (TMPTA) and 1,6-hexanediol diacrylate (HDDA). In other uses, such as dental composite resin materials, the dimethacrylic monomers based on n-ethylene glycol are the most useful. The sensitizing capacity of various multifunctional acrylates and their cross-reactivity pattern have been investigated with the guinea pig maximization test. The tests show that BUDA (1,4-butanediol diacrylate) and HDDA are moderate to strong sensitizers and that they probably cross-react with each other. The n-ethylene glycol diacrylates and methacrylates tested are weak or non-sensitizers. Tripropylene glycol diacrylate (TPGDA) is a moderate and neopentyl glycol diacrylate (NPGDA) a strong sensitizer, whereas neopentyl glycol dimethacrylate is a non-sensitizer. The commercial PETA is a mixture of pentaerythritol tri- and tetra-acrylate (PETA-3 and PETA-4). PETA-3 is a much stronger sensitizer than PETA-4. Simultaneous reactions were seen between PETA-3, PETA-4 and TMPTA. The oligotriacrylate OTA 480 is a moderate sensitizer, but no concomitant reactions were seen with PETA-3, PETA-4 or TMPTA. Of the multifunctional acrylates tested, the di- and triacrylic compounds should be regarded as potent sensitizers. The methacrylated multifunctional acrylic compounds are weak or non-sensitizers.

UV-Curing of Nanoparticle Reinforced Acrylates

International Nuclear Information System (INIS)

Bauer, F.

2006-01-01

Polymer reinforcement by silica and alumina nanoparticles evidently yields improved surface hardness. Single mixing of nanoparticles into an acrylate formulations, however, leads to highly viscous solutions inappropriate for coating procedures. The incompatibility of inorganic fillers and organic polymers can be avoided by surface modification providing an interface between the two dissimilar materials. For example, vinyltrimethoxysilane (VTMO) can react via hydrolysis/condensation reactions with hydroxyl groups present on the inorganic surface and should bond via the polymerisation-active vinyl group to an acrylate resin through crosslinking reactions. Grafting reactions of surface OH groups and different trialkoxysilanes were studied by thermogravimetry, infrared, and multinuclear NMR spectroscopy. The copolymeri-zation of modified nanoparticles with the acrylate matrix has been investigated by 13 C NMR spectroscopy. UV curing under nitrogen inertization revealed a lower reactivity of vinyl groups of VTMO-modified silica compared to grafted methacryloxypropyl-trimethoxysilane (MEMO) which showed complete conversion of olefinic carbons (signals at 120 - 140 ppm). Under conditions of oxygen inhibition, the effect of the kind and the concentration of photoinitiator on the photopoly-merization reaction was studied. Compared to neat polyacrylate coatings the nanocomposite materials exhibit markedly improved properties, e.g., heat, scratch, and abrasion resistance. However, a much better abrasion resistance was obtained for coatings containing both silica nano-particles and corundum microparticles. In particular cases, radiation curing with 172 nm photons generated by Xe excimer was performed to obtain structured polymer surfaces, i.e., matting of the reinforced acrylate coatings

Fundus autofluorescence patterns in primary intraocular lymphoma.

Science.gov (United States)

Casady, Megan; Faia, Lisa; Nazemzadeh, Maryam; Nussenblatt, Robert; Chan, Chi-Chao; Sen, H Nida

2014-02-01

To evaluate fundus autofluorescence (FAF) patterns in patients with primary intraocular (vitreoretinal) lymphoma. Records of all patients with primary intraocular lymphoma who underwent FAF imaging at the National Eye Institute were reviewed. Fundus autofluorescence patterns were evaluated with respect to clinical disease status and the findings on fluorescein angiography and spectral-domain optical coherence tomography. There were 18 eyes (10 patients) with primary intraocular lymphoma that underwent FAF imaging. Abnormal autofluorescence in the form of granular hyperautofluorescence and hypoautofluorescence was seen in 11 eyes (61%), and blockage by mass lesion was seen in 2 eyes (11%). All eyes with granular pattern on FAF had active primary intraocular lymphoma at the time of imaging, but there were 5 eyes with unremarkable FAF, which were found to have active lymphoma. The most common pattern on fluorescein angiography was hypofluorescent round spots with a "leopard spot" appearance (43%). These hypofluorescent spots on fluorescein angiography correlated with hyperautofluorescent spots on FAF in 5 eyes (36%) (inversion of FAF). Nodular hyperreflective spots at the level of retinal pigment epithelium on optical coherence tomography were noted in 43% of eyes. The hyperautofluorescent spots on FAF correlated with nodular hyperreflective spots on optical coherence tomography in 6 eyes (43%). Granularity on FAF was associated with active lymphoma in majority of the cases. An inversion of FAF (hyperautofluorescent spots on FAF corresponding to hypofluorescent spots on fluorescein angiography) was observed in less than half of the eyes.

WHAT HAPPENS TO INTRAOCULAR PRESSURE AFTER PERIBULBAR ANAESTHESIA?

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Krishnamoorthy Segharipuram Ranganathan

2017-08-01

Full Text Available BACKGROUND Most of intraocular surgeries are done under local anaesthesia. The peribulbar anaesthesia provides adequate anaesthesia and akinesia. There is no reported intraoperative and/or postoperative amaurosis. The peribulbar anaesthesia provides adequate anaesthesia and akinesia. The disadvantages of it are the larger quantity of the aesthetic agent. Increasing the bulk load on the globe and a reported rise of intraocular pressure. MATERIALS AND METHODS A study of fifty cases was conducted in patients who received peribulbar anaesthesia undergoing cataract extraction with intraocular lens implantation and their intraocular pressures were noted and studied after giving the peribulbar anaesthesia all given by the same surgeon. RESULTS This study did show that the peribulbar anaesthesia increases the intraocular pressure in all the cases. The external ocular compression indeed helps to dissipate the anaesthetic load thereby reducing the enormous rise in IOP, which is only expected if you recollect the fact that the eyeball occupies one sixth of the total volume of the orbit that is 5 mL and 30 mL. The volume of peribulbar anaesthesia (6 mL does add its effects to increase the IOP. Hence, a properly planned post peribulbar compression helps to minimise the transient rise in IOP. CONCLUSION Summarising the study, it is better to give peribulbar injection initially followed by external ocular compression after a delay of at least 2 to 5 minutes. It is also advised that an initial compression maybe given in slightly risk cases, so that the peribulbarinduced rise may not be alarming. The anaesthetic solution maybe fragmented and the second injection maybe delayed by 5 minutes or omitted if good akinesia and anaesthesia are achieved already.

(Meth)Acrylate Occupational Contact Dermatitis in Nail Salon Workers: A Case Series.

Science.gov (United States)

DeKoven, Samuel; DeKoven, Joel; Holness, D Linn

Recently, many cases of acrylate-associated allergic contact dermatitis have appeared among nail salon workers. Common acrylate-containing products in nail salons include traditional nail polish, ultraviolet-cured shellac nail polish, ultraviolet-cured gel nails, and press-on acrylic nails. Nail salon technicians seen in the occupational medicine clinic in 2015 and 2016 were identified, and their patch test results and clinical features were summarized. Patch testing was done with the Chemotechnique (Meth)Acrylate nail series, and either the North American Standard series or the North American Contact Dermatitis Group screening series. Six patients were identified, all women, ages 38 to 58. Common presentations included erythematous dermatitis of the dorsa of the hands, palms, and forearms and fissures on the fingertips. Less common sites of eruptions included the periorbital region, cheeks, posterior ears, neck, sacral area, lateral thighs, and dorsa of the feet. All patients reacted to hydroxyethyl methacrylate, and 5 patients reacted to ethyl acrylate. Each patient also reacted to (meth)acrylates that are not found on either standard series, including ethyleneglycol dimethacrylate, 2-hydroxypropyl methacrylate, and 2-hydroxyethyl acrylate. The authors report 6 cases of allergic contact dermatitis to acrylates in nail technicians seen over the past year, representing a new trend in their clinic. These cases are reflective of a growing trend of nail technicians with allergic contact dermatitis associated with occupational (meth)acrylate exposure. Efforts to improve prevention are needed.

Fabrication of hydrophobic/super-hydrophobic nanofilms on magnesium alloys by polymer plating

Energy Technology Data Exchange (ETDEWEB)

Kang Zhixin, E-mail: zxkang@scut.edu.cn; Lai Xiaoming; Sang Jing; Li Yuanyuan

2011-11-01

Hydrophobic/super-hydrophobic nanofilms with improved corrosion resistance were fabricated on the surfaces of Mg-Mn-Ce magnesium alloy by a surface modification technique, named as polymer plating, which has been developed to modify superficial characteristics of magnesium alloys with polymeric nanofilms through synthesized organic compounds of triazine dithiol containing functional groups. The nanofilms were prepared by the electrochemical and polymerization reactions during polymer plating analyzed from characteristics of Fourier transform infrared spectrophotometer, X-ray photoelectron spectroscopy and scanning electron microscopy. The fabricated nanofilms changed the surface wettability of blank magnesium alloy from hydrophilic to hydrophobic with contact angle 119.0 Degree-Sign of distilled water with lower surface free energy of 20.59 mJ/m{sup 2} and even super-hydrophobic with contact angle 158.3 Degree-Sign with lowest surface free energy of 4.68 mJ/m{sup 2} by different functional nanofilms on their surfaces. Alteration of wettability from hydrophilic to hydrophobic and super-hydrophobic resulted from their low surface free energy and surface morphology with micro- and nano-rough structures. The corrosion behaviors from potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) show that the super-hydrophobic nanofilm has higher corrosion resistance and stability in 0.1 mol/L NaCl solution and lower corrosion current density (I{sub corr}) with R{sub ct} increasing two orders of magnitude of 16,500 {Omega}{center_dot}cm{sup 2} compared to that obtained for blank of 485 {Omega}{center_dot}cm{sup 2}.

Fabrication of hydrophobic/super-hydrophobic nanofilms on magnesium alloys by polymer plating

International Nuclear Information System (INIS)

Kang Zhixin; Lai Xiaoming; Sang Jing; Li Yuanyuan

2011-01-01

Hydrophobic/super-hydrophobic nanofilms with improved corrosion resistance were fabricated on the surfaces of Mg–Mn–Ce magnesium alloy by a surface modification technique, named as polymer plating, which has been developed to modify superficial characteristics of magnesium alloys with polymeric nanofilms through synthesized organic compounds of triazine dithiol containing functional groups. The nanofilms were prepared by the electrochemical and polymerization reactions during polymer plating analyzed from characteristics of Fourier transform infrared spectrophotometer, X-ray photoelectron spectroscopy and scanning electron microscopy. The fabricated nanofilms changed the surface wettability of blank magnesium alloy from hydrophilic to hydrophobic with contact angle 119.0° of distilled water with lower surface free energy of 20.59 mJ/m 2 and even super-hydrophobic with contact angle 158.3° with lowest surface free energy of 4.68 mJ/m 2 by different functional nanofilms on their surfaces. Alteration of wettability from hydrophilic to hydrophobic and super-hydrophobic resulted from their low surface free energy and surface morphology with micro- and nano-rough structures. The corrosion behaviors from potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) show that the super-hydrophobic nanofilm has higher corrosion resistance and stability in 0.1 mol/L NaCl solution and lower corrosion current density (I corr ) with R ct increasing two orders of magnitude of 16,500 Ω·cm 2 compared to that obtained for blank of 485 Ω·cm 2 .

[Contact dermatitis caused by acrylates among 8 workers in an elevator factory].

Science.gov (United States)

Pérez-Formoso, J L; de Anca-Fernández, J; Maraví-Cecilia, R; Díaz-Torres, J M

2010-05-01

Acrylates are widely used low-molecular-weight substances, initially introduced in industry in the 1930s and subsequently applied also in medicine and the home. One of their main features is the ability to undergo polymerization. The most commonly used acrylic compounds are cyanoacrylates, methacrylates, and acrylates. To confirm suspicion of occupational disease in a group of workers in an elevator factory. We studied 8 patients with dermatitis of the hands and finger pads. In their work, the patients came into contact with acrylates. Patch testing was applied with an acrylate panel (BIAL-Aristegui, Bilbao, Spain). Seven of the patients (87. 5%) had a positive result with 1% ethylene glycol dimethacrylate. Positive were also observed for 2% hydroxyethyl methacrylate (5 patients, 62. 5%), 1% triethylene glycol dimethacrylate (4 patients, 50%), 10% ethyl methacrylate monomer (3 patients, 37. 5%), 10% methyl methacrylate monomer (2 patients, 25%), 1% ethyl acrylate (1 patient, 12. 5%), and 0. 1% acrylic acid (1 patient, 12. 5%). We highlight the strong sensitizing capacity of acrylates and the importance of taking all necessary preventive measures in industries where these substances are used. Such measures should include avoidance of contact with the product in cases where sensitization has been confirmed.

Analysis and Testing of Bisphenol A-Free Bio-Based Tannin Epoxy-Acrylic Adhesives

OpenAIRE

Jahanshahi , Shayesteh; Pizzi , Antonio; Abdulkhani , Ali; Shakeri , Alireza

2016-01-01

International audience; A tannin-based epoxy acrylate resin was prepared from glycidyl ether tannin (GET) and acrylic acid. The influence of the reaction condition for producing tannin epoxy acrylate was studied by FT-MIR, C-13-NMR, MALDI-TOF spectroscopy and shear strength. The best reaction conditions for producing tannin epoxy acrylate resin without bisphenol A was by reaction between GET and acrylic acid in the presence of a catalyst and hydroquinone at 95 degrees C for 12 h. FT-MIR, C-13...

Visual outcome with the Oculentis Mplus intraocular lens

OpenAIRE

Si-Yuan Liu; Xu Yang

2017-01-01

AIM: To evaluate the visual outcome of Oculentis Mplus intraocular lens(IOL).METHODS: Totally 20 eyes in 20 patients received phacoemulsification and Oculentis Mplus intraocular lens implantation were as test group, and 20 eyes(Aspira-aA IOL)were as control group. The following postoperative examinations were performed after operation for 3mo: uncorrected visual acuity of distance and near, refractive results, UBM examination, the rate of wearing spectacles and the complications. RESULTS: At ...

Towards customized intraocular lenses

NARCIS (Netherlands)

de Jong, Tim

2017-01-01

In the eye there are two refractive components that make light focus on the retina and let you see: the cornea and the lens. When a eye develops cataract the lens becomes caractarous and is removed and replaced with a synthetic intraocular lens during a cataract surgery procedure. Although there was

In vitro cytotoxicity of self-curing acrylic resins of different colors

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Luciana Borges Retamoso

2014-08-01

Full Text Available OBJECTIVE: The aim of this study was to assess the in vitro cytotoxicity of acrylic resins of different colors over time. METHODS: Specimens were divided into 4 groups (n = 6 according to the color of the acrylic resin (Orto Class, Clássico, Campinas, São Paulo, Brazil: Group 1: clear acrylic resin; group 2: pink acrylic resin; group 3: blue acrylic resin and group 4: green acrylic resin. All specimens were fabricated according to the mass manipulation technique and submitted to mechanical polishing protocol. The control was performed with an amalgam specimen (C+, a glass specimen (C- and cell control (CC. Specimens were immersed in Minimum Eagle's Medium (MEM and incubated for 24 h at 37o C. The extracts from the experimental material were filtered and mixed with L929 fibroblast. Cytotoxicity was evaluated at 4 different times, 24, 48, 72 and 168 h. After contact, cells were incubated for 24 h and added to 100 µ of 0.01% neutral red dye. The cells were incubated for 3 h for pigment incorporation and fixed. Cells viability was determined by a spectroscopic (BioTek, Winooski, Vermont, USA with a 492-nm wavelength λ=492 nm. RESULTS: There were no statistical differences between the experimental groups and the CC and C- groups. CONCLUSION: Clear, pink, blue and green self-curing acrylic resins fabricated by means of the mass manipulation technique and mechanically polished are not cytotoxic. Neither the pigment added to the self-curing acrylic resin nor the factor of time influenced the cytotoxicity of the material.

Clinical study on the incidence of vancomycin intraocular injection in treatment with suppurative endophthalmitis

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Yi-Qin Duan

2015-05-01

Full Text Available AIM:To estimate the clinical significance of the microculture of humor and vitreous and vancomycin intraocular injection in treatment of suppurative endophthalmitis associated with intraocular foreign bodies.METHODS: Totally 65 patients with penetrating eye trauma and retained intraocular foreign bodies in emergency operation and intraocular injection from January 2012 to September 2014 were regarded as the study group, another 62 patients with penetrating eye trauma and retained intraocular foreign bodies in emergency operation without intraocular injection before August 2011 were regarded as the control group. Aqueous humor and vitreous humor were taken from each patient of the study group and the control group for bacteria and fungus cultivation. The study group was treated with 1mg vancomycin intraocular injection after operation, while the control group was not. RESULTS: The incidence of endophthalmitis in the control group was 16%(10 cases, while in the study group was 3%(2 cases, with significant difference between two groups(x2=6.32, PP>0.05. The positive rate of vitreous humor germiculture in study group was 14%(9 cases, and the incidence of endophthalmitis was 3%. The positive rate of vitreous humor germiculture in control group was 11%(7 casesand the incidence of endophthalmitis was 16%, with significant differences between two groups(PCONCLUSION: Intraocular foreign bodies treated with emergency operation and vancomycin intraocular injections can decrease the incidence of suppurative endophthalmitis and have a good vision prognosis for the second stage of operation.

Survey of Intraocular Antibiotics Prophylaxis Practice after Open Globe Injury in China.

Directory of Open Access Journals (Sweden)

Bingsheng Lou

Full Text Available To elucidate the Chinese practice of intraocular antibiotics administration for prophylaxis after open globe injury.A cross-sectional questionnaire survey was performed online by scanning a Quickmark (QR code with smartphones at the 20th Chinese National Conference of Ocular Trauma in November 2014.A total of 153 (30.6% of all participators at the conference responded. Of the respondents, 20.9% were routinely administered with prophylactic intraocular injection of antibiotics at the conclusion of the primary eye repair, and 56.9% were used only in cases with high risk of endophthalmitis development. The intraocular route of delivery was mainly included with intracameral injection (47.9% and intravitreal injection (42.0%. Cephalosporins (53.8% and vancomycin (42.0% were the main choices of antibiotic agents, followed by fluoroquinolones (24.3%, and aminoglycosides (13.4%. Only 21.9% preferred a combination of two or more two drugs routinely. In addition, significantly more respondents from the referral eye hospital (92.7% replied using intraocular antibiotics injection for prophylaxis compared to those respondents from the primary hospital (69.4% (p = 0.001, Fisher's exact test.Intraocular antibiotics injection for post-traumatic endophthalmitis prophylaxis is widely used in China. However, the choice of antibiotic agents and the intraocular route of delivery vary. A well-designed clinical trial is needed to establish a standardized protocol of intraocular antibiotics administration for post-traumatic endophthalmitis prophylaxis.

The evolution of palm oil acrylates within 20 years in Nuclear Malaysia

International Nuclear Information System (INIS)

Mek Zah Salleh; Rida Tajau; Nurul Huda Mudri

2016-01-01

Acrylated palm oil was synthesized from epoxidized palm oil (EPOP), in early 1989, through acrylation/methacrylation process at Radiation Technology Division laboratory. The acrylated products namely Epoxidized Palm Oil Acrylate/Methacrylate (EPOLA/ EPOMA), with the molecular weight around 2000-3000 g/mol, was found curable when subjected to UV or EB irradiations. Isocyanation of EPOLAs resulted in a resin called Palm Oil Based Urethane Acrylate (POBUA). POBUA possess certain advantages over EPOLA such as much higher molecular weight between 5000 to 20000 g/ mol, better curing speed, crosslinking density, higher abrasion resistance and also higher pendulum hardness. Hyper branched polyurethane acrylate (HBPUA) from palm oil oleic was synthesized by a three-step reaction in 2012. The reaction was confirmed by several analytical data; hydroxyl value (OHV), FTIR, GPC and NMR spectroscopy analyses. The thermal decomposition of HBPUA formulations shows good thermal stability up to 450 degree Celsius. (author)

Mean intraocular pressure in hypertensive adults

International Nuclear Information System (INIS)

Irum, S.; Malik, A.M.; Saeed, M.

2015-01-01

To determine the mean Intraocular Pressure (IOP) in already diagnosed adult hypertensive patients with different grades of hypertension. Study Design: Cross-sectional descriptive study. Place and Duration of Study: Combined Military Hospital, Lahore, from March 2012 to Aug 2012. Patients and Methods: A total of 178 already diagnosed hypertensive patients were selected. A detailed history of ocular or systemic diseases was taken. Intraocular pressure was measured with help of Goldmann applanation tonometer. Three consecutive readings of IOP of each eye were taken at 30 minutes interval and mean calculated. Blood pressure was recorded in seated position from right upper arm, by mercury sphygmomanometer. Blood pressure measurements were determined by taking the mean value of three systolic and diastolic readings. Results: The results of intraocular pressure (IOP) between various grades of hypertension were determined. There was an increase in mean IOP with rise in blood pressure. The subjects with grade I hypertension showed a mean IOP of 13.95 ± 3.74 mmHg, while grade II and grade III hypertensive subjects had mean IOPs as 18.10 ± 3.32 and 20.21 ± 2.52 mmHg respectively. Conclusion: A higher value of mean IOP was found with increase in systolic and diastolic blood pressures. (author)

Removal of Silicone Oil From Intraocular Lens Using Novel Surgical Materials

Science.gov (United States)

Paschalis, Eleftherios I.; Eliott, Dean; Vavvas, Demetrios G.

2014-01-01

Purpose To design, fabricate, and evaluate novel materials to remove silicone oil (SiO) droplets from intraocular lenses (IOL) during vitreoretinal surgery. Methods Three different designs were fabricated using soft lithography of polydimethylsiloxane (PDMS), three-dimensional (3D) inverse PDMS fabrication using water dissolvable particles, and atomic layer deposition (ALD) of alumina (Al2O3) on surgical cellulose fibers. Laboratory tests included static and dynamic contact angle (CA) measurements with water and SiO, nondestructive x-ray microcomputer tomography (micro-CT), and microscopy. SiO removal was performed in vitro and ex vivo using implantable IOLs and explanted porcine eyes. Results All designs exhibited enhanced hydrophobicity and oleophilicity. Static CA measurements with water ranged from 131° to 160° and with SiO CA approximately 0° in 120 seconds following exposure. Nondestructive x-ray analysis of the 3D PDMS showed presence of interconnected polydispersed porosity of 100 to 300 μm in diameter. SiO removal from IOLs was achieved in vitro and ex vivo using standard 20-G vitrectomy instrumentation. Conclusion Removal of SiO from IOLs can be achieved using materials with lower surface energy than that of the IOLs. This can be achieved using appropriate surface chemistry and surface topography. Three designs, with enhanced hydrophobic properties, were fabricated and tested in vitro and ex vivo. All materials remove SiO within an aqueous environment. Preliminary ex vivo results were very promising, opening new possibilities for SiO removal in vitreoretinal surgeries. Translational Relevance This is the first report of an instrument that can lead to successful removal of SiO from the surface of IOL. In addition to the use of this instrument/material in medicine it can also be used in the industry, for example, retrieval of oil spills from bodies of water. PMID:25237593

Removal of Silicone Oil From Intraocular Lens Using Novel Surgical Materials.

Science.gov (United States)

Paschalis, Eleftherios I; Eliott, Dean; Vavvas, Demetrios G

2014-09-01

To design, fabricate, and evaluate novel materials to remove silicone oil (SiO) droplets from intraocular lenses (IOL) during vitreoretinal surgery. Three different designs were fabricated using soft lithography of polydimethylsiloxane (PDMS), three-dimensional (3D) inverse PDMS fabrication using water dissolvable particles, and atomic layer deposition (ALD) of alumina (Al 2 O 3 ) on surgical cellulose fibers. Laboratory tests included static and dynamic contact angle (CA) measurements with water and SiO, nondestructive x-ray microcomputer tomography (micro-CT), and microscopy. SiO removal was performed in vitro and ex vivo using implantable IOLs and explanted porcine eyes. All designs exhibited enhanced hydrophobicity and oleophilicity. Static CA measurements with water ranged from 131° to 160° and with SiO CA approximately 0° in 120 seconds following exposure. Nondestructive x-ray analysis of the 3D PDMS showed presence of interconnected polydispersed porosity of 100 to 300 μm in diameter. SiO removal from IOLs was achieved in vitro and ex vivo using standard 20-G vitrectomy instrumentation. Removal of SiO from IOLs can be achieved using materials with lower surface energy than that of the IOLs. This can be achieved using appropriate surface chemistry and surface topography. Three designs, with enhanced hydrophobic properties, were fabricated and tested in vitro and ex vivo. All materials remove SiO within an aqueous environment. Preliminary ex vivo results were very promising, opening new possibilities for SiO removal in vitreoretinal surgeries. This is the first report of an instrument that can lead to successful removal of SiO from the surface of IOL. In addition to the use of this instrument/material in medicine it can also be used in the industry, for example, retrieval of oil spills from bodies of water.

Pigment dispersion syndrome associated with intraocular lens implantation: a new surgical technique.

Science.gov (United States)

Canut Jordana, M Isabel; Pérez Formigó, Daniel; Abreu González, Rodrigo; Nadal Reus, Jeroni

2010-11-11

We report the case of a myopic patient who, after intraocular lens transplant in the posterior chamber, suffered elevated intraocular pressure due to pigment dispersion, with recurrent episodes of blurred vision. The patient was treated with a new surgical technique that can avoid potential iridolenticular contact. Complete ophthalmologic examination and optical coherence tomography (OCT) of the anterior segment were performed. Contact between the pigmentary epithelium and the iris with an intraocular lens was revealed by utrasound biomicroscopy and OCT. In this case, Nd:YAG laser iridotomy and laser iridoplasty were not effective for iridolenticular separation and control of the pigment dispersion. We propose a new technique: stitches on the surface of the iris to obtain good iridolenticular separation and good intraocular pressure control. Stitches on the iris surface should be considered as optional therapy in pigmentary glaucoma secondary to intraocular lens implantation. This surgical technique can avoid potential iridolenticular contacts more definitively.

Preparation of Photoresponsive Functionalized Acrylic Nanoparticles Cantaining Carbazole Groups for Smart Cellulosic Papers

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Jaber Keyvan Rad

2017-11-01

Full Text Available Photoresponsive functionalized polymer nanoparticles were prepared as useful materials for preparation of smart papers. Such polymer nanoparticles have wide applications in several fields including papers, sensors, bioimaging and biomedicine. First, carbazole as a photosensitive compound was modified with 2-bromoethanol through substitution nucleation reaction to its hydroxyl derivative (N-(2-hydroxyethyl carbazole, CzEtOH. The synthesis of 2-N-carbazolylethyl acrylate (CzEtA monomer was carried out by modification reaction of CzEtOH with acryloyl chloride and the chemical structures of the products were characterized. Next, CzEtA, methyl methacrylate (MMA and butyl acrylate were copolymerized to prepare photoresponsive functionalized polymer nanoparticles through mini-emulsion polymerization in order to form a hydrophobic core. This was followed by copolymerization of MMA and glycidyl methacrylate by seeded emulsion polymerization to give a functionalized outer layer on the latex particles. Absorption characteristics, size, size distribution (narrow size distribution and morphology of the nanoparticles were studied by ultraviolet-visible (UV-Vis spectroscopy, dynamic laser light scattering (DLS analysis and scanning electron microscopy (SEM micrographs, respectively. Finally, due to the importance of photoresponsive smart papers and their wide applications, cellulosic fibers were reacted with the prepared functionalized latex particles for preparation of smart papers. Morphology of the fibers was investigated with respect to the surface-immobilized polymers on the cellulosic paper and their smart behavior was evaluated by UV irradiation at 254 nm. The results revealed fast color changes and the obtained cellulosic papers became violet upon irradiation. This work shows some promising feature of these materials for preparation of anti-counterfeiting papers, where the safety becomes a major concern.

Intraocular pressure variations during zygomatic fracture reduction and fixation: a clinical study.

LENUS (Irish Health Repository)

Murray, Dylan J

2012-02-03

BACKGROUND: The reduction of midface fractures has been associated with the rare but devastating complication of blindness. An increase in intraocular pressure is important in the mechanism of blindness in this setting. In this study, the authors assessed the intraocular pressure in patients who underwent zygomatic fracture reduction (with or without fixation). METHODS: Using applanation tonometry, 29 patients underwent intraocular pressure measurements before, during, and after fracture fixation. The contralateral pressures were measured and used as the control. RESULTS: There were 29 patients with a mean age of 35 years, and the mean time to surgery was 5 days. Preoperatively, all patients had normal intraocular pressures and normal visual acuity. All patients underwent a Gillies lift and 18 patients required open reduction and fixation of the frontozygomatic suture (n = 4) or the infraorbital margin (n = 2), and the remainder (n = 12) required fixation of both points. There was no statistically significant increase in the intraocular pressures following the reduction of uncomplicated zygomatic fractures. Statistically significant pressure reductions were noted immediately after reduction and fixation. CONCLUSIONS: The surgical reduction of uncomplicated zygomatic fractures has no adverse effect on the intraocular pressure. It is the authors\\' opinion that adjunctive measures to reduce the pressures are unnecessary.

Topical tissue plasminogen activator appears ineffective for the clearance of intraocular fibrin.

Science.gov (United States)

Zwaan, J; Latimer, W B

1998-06-01

To determine the efficacy of topical tissue plasminogen activator (tPA) for the resolution of postoperative or inflammatory intraocular fibrinous exudates. Each treatment consisted of drops of 1 mg/ml tPA given 9 times 5 minutes apart. Records were reviewed and the results at 24 and 48 hours were recorded. Sixty-two patients had a total of 94 treatments. Fibrin exudates following intraocular surgery in 34 patients were treated 44 times. In 6 patients there was a positive result. Fibrin associated with intraocular infection was treated in 9 patients. None showed clear improvement. Nineteen patients had a total of 34 treatments for poorly controlled intraocular pressure (IOP) after glaucoma surgery. Five patients showed adequate control of the IOP, 12 did not change, and 2 had a questionable improvement. Eleven patients had adequate IOP control after additional treatment. Seven required suture lysis, 2 ab interno bleb revision, and 2 YAG capsulotomy or iridotomy to reduce the IOP to an acceptable level. Within the limits of this retrospective study and taking into account that fibrin may resolve spontaneously, it appears that topical tPA drops are not effective for the liquefaction of intraocular fibrin after surgery or in association with intraocular inflammation. They did not improve IOP control after glaucoma surgery.

Pigment dispersion syndrome associated with intraocular lens implantation: a new surgical technique

Directory of Open Access Journals (Sweden)

M Isabel Canut Jordana

2010-11-01

Full Text Available M Isabel Canut Jordana1, Daniel Pérez Formigó1, Rodrigo Abreu González2, Jeroni Nadal Reus11Barraquer Ophthalmology Centre, Barcelona, Spain; 2University Hospital of La Candelaria, Tenerife, SpainAims: We report the case of a myopic patient who, after intraocular lens transplant in the posterior chamber, suffered elevated intraocular pressure due to pigment dispersion, with recurrent episodes of blurred vision. The patient was treated with a new surgical technique that can avoid potential iridolenticular contact.Methods: Complete ophthalmologic examination and optical coherence tomography (OCT of the anterior segment were performed.Results: Contact between the pigmentary epithelium and the iris with an intraocular lens was revealed by utrasound biomicroscopy and OCT. In this case, Nd:YAG laser iridotomy and laser iridoplasty were not effective for iridolenticular separation and control of the pigment dispersion. We propose a new technique: stitches on the surface of the iris to obtain good iridolenticular separation and good intraocular pressure control.Conclusion: Stitches on the iris surface should be considered as optional therapy in pigmentary glaucoma secondary to intraocular lens implantation. This surgical technique can avoid potential iridolenticular contacts more definitively.Keywords: pigmentary glaucoma, intraocular lens, optical coherence tomography, laser

Advanced pigment dispersion glaucoma secondary to phakic intraocular collamer lens implant

Directory of Open Access Journals (Sweden)

Clara Ye

2018-06-01

Full Text Available Purpose: We report a case of pigment dispersion glaucoma secondary to uncomplicated phakic intraocular collamer lens (ICL (Visian ICL™, Staar Inc., Monrovia, CA implant that resulted in advanced visual field loss. Observations: A 50-year-old man presented for routine follow-up status post bilateral phakic intraocular collamer lens (ICL placement 8 years earlier. He was incidentally found to have a decline in visual acuity from an anterior subcapsular cataract and elevated intraocular pressure (IOP in the left eye. There were signs of pigment dispersion and no evidence of angle closure. Diffuse optic nerve thinning was consistent with advanced glaucomatous visual field defects. Pigment dispersion was also present in the patient's right eye, but without elevated IOP or visual field defects. The patient was treated with topical glaucoma medications and the phakic ICL in the left eye was removed concurrently with cataract surgery to prevent further visual field loss. Conclusions and importance: Pigment dispersion glaucoma is a serious adverse outcome after phakic ICL implantation and regular post-operative monitoring may prevent advanced visual field loss. Keywords: Phakic intraocular lens, Intraocular collamer lens, Pigment dispersion, Glaucoma

Assessment of intraocular foreign bodies by helical-CT multiplanar imaging

International Nuclear Information System (INIS)

Papadopoulos, A.; Fotinos, A.; Maniatis, V.; Kavadias, S.; Michaelides, A.; Avouri, M.; Kalamara, C.; Stringaris, K.

2001-01-01

The aim of this study was to examine the effectiveness of helical CT in the assessment of intraocular foreign bodies, evaluating two protocols with different collimation. We performed helical-CT studies in 30 patients. Fifteen patients were examined with 1.5-mm collimation and the other 15 patients with 3.0-mm collimation. All other imaging parameters were identical in both protocols. Multiplanar images were reconstructed. The examinations were reviewed for presence, localization and size of intraocular foreign bodies. We compare our results with the surgical data. We estimate the required examination time. In the first group (collimation 1.5 mm) an intraorbital foreign body was detected in 8 of 15 patients. In 3 of 8 patients an intraocular foreign body (all were metallic) was detected. In the second group (collimation 3.0 mm) an intraorbital foreign body was detected in 9 of 15 patients. In 8 of 9 patients an intraocular foreign body (all were metallic) was detected. Our results were confirmed by surgery in all cases. Examination time was 36 s in the first group and 18 s in the second group. Computed tomography should be considered the imaging modality of choice in the assessment of metallic intraocular foreign bodies and 3.0-mm collimation is optional, because of reduced examination time and radiation exposure. (orig.)

A novel clinical sign in intraocular tuberculosis: Active chorioretinitis within chorioretinal atrophy

OpenAIRE

Avinash Pathengay; Bhavik Panchal; Himadri Choudhury; Soumyava Basu; Nidhi Relhan; Harry W. Flynn, Jr.

2017-01-01

Purpose: To report a novel clinical sign in patients with intraocular tuberculosis. The current study is an observational consecutive case series of patients diagnosed with intraocular tuberculosis managed at a tertiary eye care centre from June 1, 2012 to December 31, 2015. Observations: The diagnosis of intraocular tuberculosis was made in 6 patients based on ocular features suggestive of tuberculosis along with a positive tuberculin skin testing and chest X-ray consistent with tuberculo...

Comparison of a new refractive multifocal intraocular lens with an inferior segmental near add and a diffractive multifocal intraocular lens.

Science.gov (United States)

Alio, Jorge L; Plaza-Puche, Ana B; Javaloy, Jaime; Ayala, María José; Moreno, Luis J; Piñero, David P

2012-03-01

To compare the visual acuity outcomes and ocular optical performance of eyes implanted with a multifocal refractive intraocular lens (IOL) with an inferior segmental near add or a diffractive multifocal IOL. Prospective, comparative, nonrandomized, consecutive case series. Eighty-three consecutive eyes of 45 patients (age range, 36-82 years) with cataract were divided into 2 groups: group A, 45 eyes implanted with Lentis Mplus LS-312 (Oculentis GmbH, Berlin, Germany); group B, 38 eyes implanted with diffractive IOL Acri.Lisa 366D (Zeiss, Oberkochen, Germany). All patients underwent phacoemulsification followed by IOL implantation in the capsular bag. Distance corrected, intermediate, and near with the distance correction visual acuity outcomes and contrast sensitivity, intraocular aberrations, and defocus curve were evaluated postoperatively during a 3-month follow-up. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected near visual acuity (UNVA), corrected distance near and intermediate visual acuity (CDNVA), contrast sensitivity, intraocular aberrations, and defocus curve. A significant improvement in UDVA, CDVA, and UNVA was observed in both groups after surgery (P ≤ 0.04). Significantly better values of UNVA (P<0.01) and CDNVA (P<0.04) were found in group B. In the defocus curve, significantly better visual acuities were present in eyes in group A for intermediate vision levels of defocus (P ≤ 0.04). Significantly higher amounts of postoperative intraocular primary coma and spherical aberrations were found in group A (P<0.01). In addition, significantly better values were observed in photopic contrast sensitivity for high spatial frequencies in group A (P ≤ 0.04). The Lentis Mplus LS-312 and Acri.Lisa 366D IOLs are able to successfully restore visual function after cataract surgery. The Lentis Mplus LS-312 provided better intermediate vision and contrast sensitivity outcomes than the Acri.Lisa 366D. However, the

Synthesis and characterization of waterborne polyurethane acrylate copolymers

International Nuclear Information System (INIS)

Sultan, Misbah; Bhatti, Haq Nawaz; Zuber, Mohammad; Barikani, Mehdi

2013-01-01

Polyurethane acrylate copolymers were synthesized by emulsion polymerization process. To reduce the environmental hazards, organic solvents were replaced by eco-friendly aqueous system. Concentration of polyurethane and acrylate monomer was varied to investigate the effect of chemical composition on performance properties of copolymers. FTIR spectroscopy was used as a key tool to record the chemical synthesis route. The synthesized copolymer emulsions were characterized by evaluating their particle size, viscosity, dry weight content, chemical and water resistance. Thermal decomposition was studied by thermogravimetric analysis. Scanning electron microscope was used to visualize the morphological structure of copolymers. The experimental results indicate better polyurethane acrylate compatibility till the ratio of 30/70. However, these copolymers exhibited synergistic effects between the two polymers and revealed a remarkable improvement in numerous coating properties

Toughening epoxy acrylate with polyurethane acrylates and hyper-branched polyester in three dimensional printing

Science.gov (United States)

Fang, Chao; Li, Ning; Liu, Yang; Lu, Gang

2018-05-01

In order to improve the toughness of epoxy acrylate (EA) in three dimensional printing (3D-printing), bifunctional polyurethane acrylate (PUA) and trifunctional PUA were firstly blended with EA. The multi-indicators orthogonal experiment, designed with the indicators of tensile strength, elongation at break and impact strength, was used to find out the optimal formulation. Then, hyper-branched polyesters (HBPs) was added to improve the toughness of the photocurable system. The microstructures of the cured specimens were characterized by optical microscopy and scanning electron microscopy. By analyzing their mechanical properties and microstructures, it was revealed that the best addition amounts of HBP are 10 wt%. Results indicated that their toughness improved a lot comparing with pure EA. The changes of mechanical properties were characterized by DMA. The addition of HBP could cause a loss in stiffness, elasticity modulus and thermostability.

Analysis and Testing of Bisphenol A—Free Bio-Based Tannin Epoxy-Acrylic Adhesives

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Shayesteh Jahanshahi

2016-04-01

Full Text Available A tannin-based epoxy acrylate resin was prepared from glycidyl ether tannin (GET and acrylic acid. The influence of the reaction condition for producing tannin epoxy acrylate was studied by FT-MIR, 13C-NMR, MALDI-TOF spectroscopy and shear strength. The best reaction conditions for producing tannin epoxy acrylate resin without bisphenol A was by reaction between GET and acrylic acid in the presence of a catalyst and hydroquinone at 95 °C for 12 h. FT-MIR, 13C-NMR and MALDI-TOF analysis have confirmed that the resin has been prepared under these conditions. The joints bonded with this resin were tested for block shear strength. The results obtained indicated that the best strength performance was obtained by the bioepoxy-acrylate adhesive resin prepared at 95 °C for a 12-h reaction.

Electrochemical investigation on an acrylated thiophene

Energy Technology Data Exchange (ETDEWEB)

Hogervorst, A.C.R. (TNO Plastics and Rubber Research Inst., Delft (Netherlands)); Kock, T.J.J.M. (TNO Plastics and Rubber Research Inst., Delft (Netherlands)); Ruiter, B. de (TNO Plastics and Rubber Research Inst., Delft (Netherlands)); Waal, A. van der (TNO Plastics and Rubber Research Inst., Delft (Netherlands))

1993-03-22

The electrochemical behaviour of electropolymerized 2-(3-thienyl)ethyl acrylate (PAcrT) has been investigated, and compared to the behaviour of electropolymerized thiophene and 3-n-decylthiophene (PDT). The effect of electron beam irradiation on the electrochemical properties of these three polymers has been studied. It has been found that for PAcrT the oxidation wave shifts to higher potentials upon electron beam irradiation. For PDT a similar but smaller change occurs. We suggest that the shift of the oxidation wave of PAcrT is caused by cross-links, formed between the acrylate substituents, which fixate the main chain parts in twisted states and reduce the conjugation length. (orig.)

[Evaluation of accuracy of measuring intraocular pressure by handheld non-contact applanation tonometer].

Science.gov (United States)

Chen, X; Peng, D; Zhou, W; Zhong, Y

1995-06-01

To evaluate the accuracy of measuring intraocular pressure by handheld non-contact applanation tonometer. 58 patients' (113 eyes) intraocular pressure were measured by Keeler, non-contact tonometer and R 900 Goldmann applanation tonometer and the results of measurement of intraocular pressure by the two kinds of tonometers were compared. The mean intraocular pressure measured by non-contact is 16.31 +/- 5.59 mmHg and 17.49 +/- 6.13 mmHg (1 mmHg = 0.1333 kPa) by Goldmann applanation tonometer, respectively. There was no statistical significance to be found (P > 0.05) between the two methods. By linear correlation and regression analysis, a positive correlation was found between the two methods (r = 0.8942, b = 0.8154). The handheld non-contact tonometer has the same accuracy and reliability of measurement of intraocular pressure comparing with Goldmann applanation tonometer, and it can be used in glaucoma clinic and screening.

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

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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

Preparations and applications in UV curing coatings of epoxy acrylates containing carboxyl

International Nuclear Information System (INIS)

Wu Yu Min

1999-01-01

This paper introduces preparations of epoxy acrylates containing carboxyl through the reactions of epoxy acrylates with butanedioic anhydride, pentanedioic anhydride, cis-butenedioic anhydride, phthalic anhydride, tetrabromophthalic anhydride and -tetrahydrophthalic anhydride. These epoxy acrylates containing carboxyl have been applied to UV-curing coatings and their effects on properties of UV-curing coatings have been studied

Retropupillary iris claw intraocular lens implantation in aphakia for dislocated intraocular lens.

Science.gov (United States)

Faria, Mun Yueh; Ferreira, Nuno Pinto; Pinto, Joana Medeiros; Sousa, David Cordeiro; Leal, Ines; Neto, Eliana; Marques-Neves, Carlos

2016-01-01

Nowadays, dislocated intraocular lenses (IOLs) and inadequate capsular support are becoming a challenge for every ophthalmic surgeon. Explantation of dislocated IOL and iris claw IOL (ICIOL) are the techniques that have been used in our ophthalmic department. The aim of this study is to report our technique for retropupillar ICIOL. This study is a retrospective case series. A total of 105 eyes with dislocated IOL from the patients at the Department of Ophthalmology in Santa Maria Hospital, a tertiary reference hospital in Lisbon, Portugal, from January 2012 until January 2016, had been analyzed. Of these 105 eyes, 66 eyes had dislocated one-piece IOL and 39 eyes had dislocated three-piece IOL. The latter underwent iris suture of the same IOL and were excluded from this study. The remaining 66 eyes with dislocated one-piece IOL underwent pars plana vitrectomy, that is, explantation of dislocated IOL through corneal incision and an implantation of retropupillary ICIOL. Operative data and postoperative outcomes included best corrected visual acuity, IOL position, intraocular pressure, pigment dispersion, clinical signs of endothelial cell loss, and anterior chamber depth. The mean follow-up was 23 months (range: 6-48 months). The mean preoperative best corrected visual acuity was 1.260±0.771 logMAR, and postoperative best corrected visual acuity was 0.352±0.400 logMAR units. Mean vision gain was 0.909 logMar units. The patients had the following complications: 1) retinal detachment was found in one patient, 2) corneal edema was found in three patients, 3) high intraocular pressure was observed in twelve patients, 4) subluxation of the IOL was observed in one patient, and 5) macular edema was found in three eyes. The results demonstrate that retropupillary ICIOL is an easy and effective method for the correction of aphakia in patients not receiving capsule support. The safety of this procedure must be interpreted in the context of a surgery usually indicated in

Ultraviolet curing of acrylated liquid natural rubber for surface coating application

OpenAIRE

Kannikar Kwanming; Pairote Klinpituksa; Wae-asae Waehamad

2009-01-01

Ultraviolet curable acrylated liquid natural rubber was prepared by grafting of photosensitive molecule onto liquid natural rubber for surface coating application. The liquid natural rubber (LNR) was firstly obtained by degradation of natural rubber latex with hydrogen peroxide and cobalt acetylacetonate at 65oC for 72 hrs. The preparation of acrylated natural rubber was carried out by the reaction of acrylic acid and epoxidized liquid natural rubber (ELNR) prior obtained from LNR with formic...

Sutureless, Glueless, Scleral Fixation of Single-Piece and Toric Intraocular Lens: A Novel Technique

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Aditya Kelkar

2015-07-01

Full Text Available Sutureless, glueless, scleral fixation of an intraocular lens is a known technique of fixing a lens in the scleral pockets. However, this technique is applied to single-piece and toric lenses instead of 3-piece lenses, allowing the advantage of the use of premium lenses in patients with poor capsular support. Favourable results without complications of pigment dispersion, iris transillumination defects, dysphotopsia, elevated intraocular pressure, intraocular hemorrhage and cystoid macular edema with a well-centered, stable intraocular lens have been observed in the 3-month postoperative period in both cases.

Flurbiprofen and intraocular pressure.

Science.gov (United States)

Gieser, D K; Hodapp, E; Goldberg, I; Kass, M A; Becker, B

1981-07-01

Systemic or topical administration of corticosteroids may produce a rise in intraocular pressure (IOP). Nonsteroidal anti-inflammatory drugs (NSAI drugs) are alternate therapy for ocular inflammatory disease. Flurbiprofen, a new NSAI drug, was tested in double-masked fashion to delineate its effect on IOP. Flurbiprofen did not alter IOP in known high corticosteroid responders nor did it block corticosteroid-induced ocular hypertension.

Professor Peter Choyce: an early pioneer of intraocular lenses and corneal/refractive surgery.

Science.gov (United States)

Pandey, Suresh K; Apple, David J

2005-06-01

Professor Peter Choyce, FRCS, DOMS, MS, was one of the pioneers of intraocular lens implant surgery. He developed an interest in artificial lens implantation following cataract surgery, a procedure that was widely criticized by the ophthalmic establishment in the UK, Europe, North America and other countries. Owing to the opposition to the intraocular lenses, Peter Choyce together with Sir Harold Ridley co-founded the International Intraocular Implant Club in 1966, which was responsible for the gradual acceptance of artificial lens implantation. Peter Choyce developed several models of intraocular lens, but did not patent the majority of them. The Choyce Mark IX, manufactured by Rayner Intraocular Lenses, became the first US Food and Drug Administration-approved intraocular lens in 1981. A review of Peter Choyce's record confirms a significant number of original innovations in the field of anterior segment surgery, including many procedures taken for granted today, but not associated with his name. These include early work on both kerato- and intraocular lens-refractive procedures, keratoprosthesis, pioneering paediatric implant procedures and others. Unfortunately his tenacious adherence to anterior chamber lens technology, while in general clinically sound, caused many to question his influence and hence he remained poorly understood even until after his death. He passed away on 8 August 2001 after a long fight with colon cancer. In this article, we provide evidence and elaborate Peter Choyce's accomplishments, which places him as one of the most innovative ophthalmologist in his surgical field in the twentieth century.

Experiencia con la lente intraocular RAYNER 620H Experience gained with the use of intraocular lens RAYNER 620 H

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Juan Raúl Hernández Silva

2008-06-01

Full Text Available Un importante eslabón en el progreso alcanzado en la cirugía de cataratas, está fundamentado en el desarrollo industrial paralelo que ha ocurrido durante los últimos años con la introducción de nuevos modelos de lentes intraoculares, como el Rayner 620 H; el perfeccionamiento del instrumental quirúrgico, sistemas de aspiración e irrigación bimanual y bisturí con la medida exacta para colocar el inyector de la lente intraocular. La lente intraocular Rayner 620H significó un gran paso para la facoemulsificación y el control de la opacidad de la cápsula posterior posoperatoria por el diseño peculiar de su óptica y hápticos, que permiten un implante seguro, fácil y una incisión mínima. Se realizó un estudio prospectivo y descriptivo, cuyo universo de estudio fueron 28 ojos con diagnóstico de cataratas a los cuales se les realizó facoemulsificación con implante de lente intraocular Rayner 620 H, en el Centro de Microcirugía Ocular del Instituto Cubano de oftalmología "Ramón Pando Ferrer" en el período comprendido entre junio de 2006 a febrero de 2007. El grupo de edades donde se encontró el de mayor número de pacientes fue en el de más de 60 años. En todos los casos hubo un aumento significativo de la agudeza visual sin corrección y con ella, del preoperatorio al posoperatorio. Hubo un aumento del cilindro queratométrico del preoperatorio al posoperatorio, pero este fue mínimo La pérdida de células endoteliales fue baja del preoperatorio al posoperatorio, respectivamente. No hubo ninguna complicación durante la cirugía ni después de esta. Evaluamos como satisfactoria la efectividad del lente intraocular Rayner 620 H, por el aumento de la agudeza visual del paciente, el bajo astigmatismo inducido, mejoría del campo visual por confrontación, mínima pérdida de células endoteliales, y ausencia de complicaciones y de deslumbramiento posoperatorio en los pacientes.An important link in the advances made by the

Technology and the use of acrylics for provisional dentine protection.

Science.gov (United States)

Kapusevska, Biljana; Dereban, Nikola; Popovska, Mirjana; Nikolovska, Julijana; Radojkova Nikolovska, Vеrа; Zabokova Bilbilova, Efka; Mijoska, Aneta

2013-01-01

Acrylics are compounds polymerized from monomers of acrylic, metacrylic acid or acrylonitrates. The purpose of this paper is to present the technology and use of acrylics for provisional dentine protection in the practice of dental prosthodontics. For this reason, we followed 120 clinical cases from the everyday clinical practice, divided into 4 groups of 30 patients who needed prosthetic reconstruction. The first group included cases in which we applied celluloid crowns for dentine protection, for the second group we used acrylic teeth from a set of teeth for complete dentures; in the third and fourth groups the fabrication was done with the system of an impression matrix and the acrylic resin block technique respectively. In all the examined patients, the gingival index by Silness and Loe and the vitality of the dental pulp were verified clinically, after preparation and 8 days from the placement of the provisional crown. The value for dental sensitivity measured after preparation was 2.59, and 8 days after the placement of the provisional crown it bwas 3.1. From these results we can conclude that after the 8th day from the placement of the provisional crown, there was an adaptation period, characterized by a decrease in the painful sensations. The value of the Silness and Loe gingival index measured after the preparation was 1.34, and 8 days from the placement of the provisional crown was 0.94. The results inclined us to the fact that the provisional acrylic crowns facilitated the reparation of the periodontal tissue.

Synthesis of Radiation Curable Palm Oil-Based Epoxy Acrylate: NMR and FTIR Spectroscopic Investigations.

Science.gov (United States)

Salih, Ashraf M; Ahmad, Mansor Bin; Ibrahim, Nor Azowa; Dahlan, Khairul Zaman Hj Mohd; Tajau, Rida; Mahmood, Mohd Hilmi; Yunus, Wan Md Zin Wan

2015-08-04

Over the past few decades, there has been an increasing demand for bio-based polymers and resins in industrial applications, due to their potential lower cost and environmental impact compared with petroleum-based counterparts. The present research concerns the synthesis of epoxidized palm oil acrylate (EPOLA) from an epoxidized palm oil product (EPOP) as environmentally friendly material. EPOP was acrylated by acrylic acid via a ring opening reaction. The kinetics of the acrylation reaction were monitored throughout the reaction course and the acid value of the reaction mixture reached 10 mg KOH/g after 16 h, indicating the consumption of the acrylic acid. The obtained epoxy acrylate was investigated intensively by means of FTIR and NMR spectroscopy, and the results revealed that the ring opening reaction was completed successfully with an acrylation yield about 82%. The UV free radical polymerization of EPOLA was carried out using two types of photoinitiators. The radiation curing behavior was determined by following the conversion of the acrylate groups. The cross-linking density and the hardness of the cured EPOLA films were measured to evaluate the effect of the photoinitiator on the solid film characteristics, besides, the thermal and mechanical properties were also evaluated.

Intraocular pressure in very low birth weight preterm infants and its association with postconceptional age

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Rodrigo L. Lindenmeyer

2012-11-01

Full Text Available OBJECTIVE: To evaluate intraocular pressure in very low birth weight preterm infants and correlate it with postconceptional age. METHODS: The intraocular pressure in a prospective cohort of very low birth weight premature infants (defined as a birth weight <1,500 g and gestational age <32 weeks admitted to Hospital de Clínicas de Porto Alegre , Brazil was evaluated weekly. The evaluated outcome was the variation in the intraocular pressure following changes in the postconceptional age (defined as the gestational age at birth plus the age in weeks at the time of examination in the weeks following preterm birth. Mixed-effects models were used for the statistical analysis to determine the intraocular pressure variation according to postconceptional age, and means and 10th and 90th percentiles were calculated for the intraocular pressure values. RESULTS: Fifty preterm infants with a mean gestational age of 29.7 ± 1.6 weeks and a mean birth weight of 1,127.7 ± 222.7 g were evaluated. The mean intraocular pressure for the entire cohort considering both eyes was 14.9 ± 4.5 mmHg, and 13.5% of all recorded intraocular pressure values were greater than 20 mmHg. The analysis revealed a mean reduction in the intraocular pressure of 0.29 mmHg for each increase in postconceptional age (p = 0.047; 95% CI: -0.58 to -0.0035. The mean intraocular pressure (P10-P90 decreased from 16.3 mmHg (10.5222.16 at 26.3 weeks to 13.1 mmHg (7.28-18.92 at 37.6 weeks of postconceptional age. CONCLUSIONS: The mean intraocular pressure in very low birth weight preterm infants was 14.9 ± 4.5 mmHg. This value decreased 0.29 mmHg per week as the postconceptional age increased.

Intraocular manifestations of mycobacterium tuberculosis: A review of the literature

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Lauren A. Dalvin

2017-05-01

Full Text Available Mycobacterium tuberculosis: is most commonly associated with pulmonary infection. However, tuberculosis (TB can also affect the eye. TB can affect nearly any tissue in the eye, and a high index of suspicion is required for accurate diagnosis, as many of the intraocular manifestations of TB can mimic other, more common diseases. Correct diagnosis is critical because systemic anti-tuberculosis treatment may be required, and vision loss or even loss of the affected eye can occur without proper treatment. Thus, it is important for ophthalmologists and infectious disease specialists to work together to accurately diagnose and treat intraocular TB. This article reports the various known presentations of intraocular TB and reviews important elements of diagnosis and treatment. Keywords: Mycobacterium, Tuberculosis, Choroidal granuloma, Retinal vasculitis

Epithelial Downgrowth after Intraocular Surgery Treated with Intracameral 5-Fluorouracil

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Nina Ni

2015-01-01

Full Text Available Purpose. To present the clinical and histopathologic correlation of two cases of epithelial downgrowth (EDG after prior intraocular surgery. Methods. Observational case reports. Results. We present two cases of EDG occurring after intraocular surgery. In both cases, after two anterior chamber injections of 5-fluorouracil (5FU, the area of EDG initially regressed. In Case 1, a limited area of EDG eventually recurred, and penetrating keratoplasty with cryotherapy was curative. In Case 2, subsequent corneal edema required Descemet-stripping automated endothelial keratoplasty, and the patient remained clinically free of EDG without further treatment. Conclusion. Intracameral 5FU may have a role in the treatment of EDG after intraocular surgery, though its precise utilization and impact remain to be defined.

Refractive results of cataract surgery using optical biometry and Haigis formula in eyes with refractive keratotomy

Directory of Open Access Journals (Sweden)

Juan Carlos Sánchez Caballero

2013-04-01

Full Text Available OBJECTIVE: To analyze refractive results in postoperative cataract surgery in eyes previously submitted to keratotomy using Haigis formula and data provided by IOL Master®optical biometer. METHODS: The measurements for IOL calculation were obtained through optical biometry by partial coherence interferometry (IOL Master®- Zeiss, 5.4 and 5.5 version that provides us with the axial length, the central keratometry of 2.5mm, white-to-white diameter and anterior chamber anatomical depth. The formula chosen was Haigis. The surgical technique applied was with the scleral incision at 1.5 mm from the limbus, with scleral-corneal tunnel of 2.2 mm wide, phacoemulsification using INFINITI Ozil®- Alcon and implantation of hydrophobic acrylic aspheric intraocular lens - SN60WF®- Alcon. RESULTS: We studied 20 eyes submitted to keratotomy in the past and currently with cataract with indication for cataract surgerywith intraocular lens implantation using phacoemulsification. Postoperative spherical equivalent was plano in 40% of the eyes and lower than -1.00 in 85% of the eyes. CONCLUSION: The optical biometry by partial coherence interferometry associated with Haigis formula is a valid alternative in IOL calculation for eyes submitted to keratotomy. The refractive results are highly predictable and reproducible.

Enzyme-Catalyzed Synthesis of Saccharide Acrylate Monomers from Nonedible Biomass

NARCIS (Netherlands)

Kloosterman, Wouter M. J.; Brouwer, Sander; Loos, Katja

Various cellulase preparations were found to catalyze the transglycosidation between cotton linters and 2-hydroxyethyl acrylate. The conversion and enzyme activity were found to be optimal in reaction mixtures that contained 5 vol% of the acrylate. The structures of the products were revealed by

Comparison between intraocular pressure spikes with water loading and postural change.

Science.gov (United States)

Chong, Calum Wk; Wang, Sarah B; Jain, Neeranjali S; Bank, Cassandra S; Singh, Ravjit; Bank, Allan; Francis, Ian C; Agar, Ashish

2016-12-01

To compare the agreement between peak intraocular pressures measured through the water drinking test and the supine test, in patients with primary open angle glaucoma. Consecutive, prospective, blinded. Twenty-one patients from the Glaucoma Unit, Prince of Wales Hospital, Sydney, Australia. For the supine test, intraocular pressure was recorded immediately after the patient had lain down and at 20 and 40 min. At the second evaluation, intraocular pressure was measured in each patient after drinking 10 mL/kg body weight of water for the water drinking test. Again, all patients had their intraocular pressure measured at 20 and 40 min (t = 20 and t = 40, respectively). Patients were excluded from the study if they had pre-existing cardiac, renal or pulmonary complications or had concurrent ocular disease or an anatomical abnormality (including angle recession, peripheral anterior synechiae and developmental anomalies of the angle) that may have influenced intraocular pressure. Bland-Altman analysis. Bland-Altman analysis indicated an overall excellent agreement in terms of mean difference between methods (1.0, -1.0 and -0.90 mmHg, at 0, 20 and 40 min, respectively). Further, with the exception of t = 40, all measured time points had 95% confidence intervals within 6.5 mmHg of their mean difference on the Bland-Altman plot. There was close agreement between the intraocular pressure values of the supine test and water drinking test. However, as the water drinking test may be uncomfortable and potentially hazardous, there is potential that the supine test may be a safer and more comfortable alternative. © 2016 Royal Australian and New Zealand College of Ophthalmologists.

Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

International Nuclear Information System (INIS)

Rida Tajau; Nurulhuda Mohd Yunus; Mohd Hilmi Mahmood; Mek Zah Salleh; Nik Ghazali Nik Salleh

2013-01-01

Full-text: The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidized palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) for example EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80 %) than the palm oil based compounds (up to 70 %), where the different is around 10-15 %. The hardness property from this two type coatings can reached until 50 % at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newton's (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photo initiator give higher adhesion property and their also showed a higher glossiness property on the glass substrate compared to the coatings containing irgacure-819 photo initiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough. (author)

Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

International Nuclear Information System (INIS)

Tajau, Rida; Mahmood, Mohd Hilmi; Salleh, Mek Zah; Salleh, Nik Ghazali Nik; Ibrahim, Mohammad Izzat; Yunus, Nurulhuda Mohd

2014-01-01

The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidised palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) i.e. EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80%) than the palm oil based compounds (up to 70%), where the different is around 10-15%. The hardness property from this two type coatings can reached until 50% at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newtons (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photoinitiator give higher adhesion property and their also showed a higher glosiness property on the glass substrate compared to the coatings containing irgacure-819 photoinitiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough

Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

Energy Technology Data Exchange (ETDEWEB)

Tajau, Rida; Mahmood, Mohd Hilmi; Salleh, Mek Zah; Salleh, Nik Ghazali Nik [Radiation Processing Technology Division, Malaysian Nuclear Agency (Nuclear Malaysia), Bangi, 43000 Kajang, Selangor (Malaysia); Ibrahim, Mohammad Izzat [Faculty of Science, University of Malaya (UM), 50603 Kuala Lumpur (Malaysia); Yunus, Nurulhuda Mohd [Faculty of Science and Technology, National University Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

2014-02-12

The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidised palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) i.e. EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80%) than the palm oil based compounds (up to 70%), where the different is around 10-15%. The hardness property from this two type coatings can reached until 50% at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newtons (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photoinitiator give higher adhesion property and their also showed a higher glosiness property on the glass substrate compared to the coatings containing irgacure-819 photoinitiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough.

A new device to noninvasively estimate the intraocular pressure produced during ocular compression

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Korenfeld MS

2016-01-01

Full Text Available Michael S Korenfeld,1,2 David K Dueker3 1Comprehensive Eye Care, Ltd., 2Department of Ophthalmology and Visual Sciences, Washington University, Washington, MO, USA; 3Hamad Medical Corporation, Doha, Qatar Purpose: To describe a noninvasive instrument that estimates intraocular pressure during episodes of external globe compression and to demonstrate the accuracy and reliability of this device by comparing it to the intraocular pressures simultaneously and manometrically measured in cannulated eyes. Methods: A thin fluid-filled bladder was constructed from flexible and inelastic plastic sheeting and was connected to a pressure transducer with high pressure tubing. The output of the pressure transducer was sent to an amplifier and recorded. This device was validated by measuring induced pressure in the fluid-filled bladder while digital pressure was applied to one surface, and the other surface was placed directly against a human cadaver eye or in vivo pig eye. The human cadaver and in vivo pig eyes were each cannulated to provide a manometric intraocular pressure control. Results: The measurements obtained with the newly described device were within ~5% of simultaneously measured manometric intraocular pressures in both a human cadaver and in vivo pig eye model for a pressure range of ~15–100 mmHg. Conclusion: This novel noninvasive device is useful for estimating the intraocular pressure transients induced during any form of external globe compression; this is a clinical setting where no other devices can be used to estimate intraocular pressure. Keywords: glaucoma, intraocular pressure, tonometer, ocular compression

Clinical Aspects of Combination of Ceramic and Acrylic Occlusal Surfaces

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Z. Ozhohan

2017-03-01

Full Text Available The objective of the research was to develop and substantiate the methods of constructing the occlusal surfaces when manufacturing aesthetic fixed restorations through the combination of different materials. Materials and methods. The study included 65 patients with ceramic and acrylic occlusal surfaces of aesthetic fixed dental prostheses. Group I included 21 patients with a combination of ceramic and acrylic occlusal surfaces. Group II included 22 patients with a combination of ceramic occlusal surfaces. Group III included 22 patients with a combination of acrylic occlusal surfaces. The patients were observed 3, 6 and 12 months after prosthetic repair. Results. The greatest increase in the occlusal contact surface area of fixed restorations was observed in Group I, that is, when combining dental prostheses with ceramic and acrylic occlusal surfaces. Considering uneven abrasion of the occlusal surfaces, we do not recommend to combine different materials when veneering the occlusal surface of the antagonistic teeth. Conclusions. This study demonstrated the important role of the correct combination of materials when veneering the occlusal surfaces. Physical and chemical properties of materials, namely the abrasion resistance play a significant role in the long-term denture functioning. The smallest increase in the occlusal contact surface area was observed in Group II when combining ceramic occlusal surfaces. It was due to a good abrasion resistance of ceramics as compared to acrylic resin as well as the presence of the glazed layer which prevents the premature abrasion of the occlusal surfaces of the antagonistic teeth due to lower surface roughness. The combination of acrylic resin and ceramics when constructing the occlusal surfaces of fixed restorations in Group I demonstrated the highest rate of the increase in the occlusal contact surface area – 9.93%. It was due to a low hardness of acrylic resin and its high surface roughness. In

Posterior Segment Intraocular Foreign Body: Extraction Surgical Techniques, Timing, and Indications for Vitrectomy

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Dante A. Guevara-Villarreal

2016-01-01

Full Text Available Ocular penetrating injury with Intraocular Foreign Body (IOFB is a common form of ocular injury. Several techniques to remove IOFB have been reported by different authors. The aim of this publication is to review different timing and surgical techniques related to the extraction of IOFB. Material and Methods. A PubMed search on “Extraction of Intraocular Foreign Body,” “Timing for Surgery Intraocular Foreign Body,” and “Surgical Technique Intraocular Foreign Body” was made. Results. Potential advantages of immediate and delayed IOFB removal have been reported with different results. Several techniques to remove IOFB have been reported by different authors with good results. Conclusion. The most important factor at the time to perform IOFB extraction is the experience of the surgeon.

Bacillus cereus panophthalmitis associated with intraocular gas bubble.

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al-Hemidan, A; Byrne-Rhodes, K A; Tabbara, K F

1989-01-01

It has become increasingly apparent that Bacillus cereus can cause a severe and devastating form of endophthalmitis following penetrating trauma by a metallic object. B. cereus is an uncommon aetiological agent in non-clostridial gas-forming infections. The patient studied in this single case report showed evidence of intraocular gas mimicking gas gangrene infection. The physiology of non-clostridial bacteria producing gas from anaerobic metabolic conditions is reviewed. Further intraocular and systemic complications which may be avoided by accurate and early diagnosis and the use of recommended treatment with antibiotics such as clindamycin. Images PMID:2493262

Hydrophobic-Core Microcapsules and Their Formation

Science.gov (United States)

Calle, Luz M. (Inventor); Li, Wenyan (Inventor); Buhrow, Jerry W. (Inventor); Jolley, Scott T. (Inventor)

2016-01-01

Hydrophobic-core microcapsules and methods of their formation are provided. A hydrophobic-core microcapsule may include a shell that encapsulates a hydrophobic substance with a core substance, such as dye, corrosion indicator, corrosion inhibitor, and/or healing agent, dissolved or dispersed therein. The hydrophobic-core microcapsules may be formed from an emulsion having hydrophobic-phase droplets, e.g., containing the core substance and shell-forming compound, dispersed in a hydrophilic phase. The shells of the microcapsules may be capable of being broken down in response to being contacted by an alkali, e.g., produced during corrosion, contacting the shell.

Surfactant and counter-ion distribution in styrene-butyl acrylate-acrylic acid dry latex submonolayers

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Keslarek Amauri José

2004-01-01

Full Text Available Styrene-butyl acrylate-acrylic acid latex submonolayers prepared using a non-reactive phosphate surfactant together with a reactive sulfonate surfactant were examined in a transmission microscope using electron energy loss spectroscopy imaging (ESI-TEM. Phosphorus is nearly absent from the particles core but it is detected in a thick shell and in unusual, strongly scattering structures with a low carbon content, and largely made out of inorganic phosphate. P is also dispersed outside the particles, while S is uniformly distributed within then. The Na and N elemental maps show that the respective monovalent ions (Na+ and NH4+ have different distributions, in the latex: Na signal within the particles is stronger than in the background, while N is accumulated at the particle borders. The distributions of surfactant and counter-ions are thus different from some current assumptions, but they support recent results on the distribution of ionic constituents in latex films, by scanning electric potential microscopy.

Influence of macular pigment optical density spatial distribution on intraocular scatter.

Science.gov (United States)

Putnam, Christopher M; Bland, Pauline J; Bassi, Carl J

This study evaluated the summed measures of macular pigment optical density (MPOD) spatial distribution and their effects on intraocular scatter using a commercially available device (C-Quant, Oculus, USA). A customized heterochromatic flicker photometer (cHFP) device was used to measure MPOD spatial distribution across the central 16° using a 1° stimulus. MPOD was calculated as a discrete measure and summed measures across the central 1°, 3.3°, 10° and 16° diameters. Intraocular scatter was determined as a mean of 5 trials in which reliability and repeatability measures were met using the C-Quant. MPOD spatial distribution maps were constructed and the effects of both discrete and summed values on intraocular scatter were examined. Spatial mapping identified mean values for discrete MPOD [0.32 (s.d.=0.08)], MPOD summed across central 1° [0.37 (s.d.=0.11)], MPOD summed across central 3.3° [0.85 (s.d.=0.20)], MPOD summed across central 10° [1.60 (s.d.=0.35)] and MPOD summed across central 16° [1.78 (s.d.=0.39)]. Mean intraocular scatter was 0.83 (s.d.=0.16) log units. While there were consistent trends for an inverse relationship between MPOD and scatter, these relationships were not statistically significant. Correlations between the highest and lowest quartiles of MPOD within the central 1° were near significance. While there was an overall trend of decreased intraocular forward scatter with increased MPOD consistent with selective short wavelength visible light attenuation, neither discrete nor summed values of MPOD significantly influence intraocular scatter as measured by the C-Quant device. Published by Elsevier España, S.L.U.

Bilateral spontaneous dislocation of posterior chamber intraocular lens in a patient with gyrate atrophy

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Michael Kinori

2012-01-01

Full Text Available We report a patient with gyrate atrophy, a rare metabolic disease, who had bilateral late spontaneous posterior dislocation of in-the-bag posterior chamber intraocular lens (PCIOL. He underwent pars plana vitrectomy, PCIOL retrieval and anterior chamber intraocular lens implantation in both eyes. This report may imply that patients with gyrate atrophy are at risk for spontaneous dislocation of intraocular lenses.

The Effect of Various Contact Lenses on Intraocular Pressure Measurement by Goldman Tonometer

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Monireh Mahjoob

2014-06-01

Full Text Available Background: Today, contact lenses have extensive usages. Contact lens places on cornea, so it may induce variation on cornea and these variations can influence the measurement of intraocular pressure (IOP by Goldman tonometer. The aim of this research was to study the effect of various contact lenses on measurement of intraocular pressure by Goldman tonometer. Materials and Methods: In this study, 80 subjects aged 18-25 were selected randomly among patients of Al-Zahra ophthalmology center. None of them has any eye pathological problems. Before wearing the lens, intraocular pressure was measured, and then patients were divided into two groups of soft and hard contact lenses. Soft and hard contact lenses were placed on the eye for two hours, and the intraocular pressure was measured again. Results: The mean of IOP before wearing contact lenses and two hours later was 15.96 mmHg and 13.93, s respectively. Paired test showed a significant difference between IOP before and after wearing contact lenses (p=0.001.There was no significant differences in mean of intraocular pressure decline before and after placing the contact lens in both soft and hard lenses. Conclusion: According to this study, the intraocular pressure decreases after wearing contact lenses (CL. This decline may be due to variation in properties of cornea after wearing CL that can also affect IOP measurement.

Water on a Hydrophobic surface

Science.gov (United States)

Scruggs, Ryan; Zhu, Mengjue; Poynor, Adele

2012-02-01

Hydrophobicity, meaning literally fear of water, is exhibited on the surfaces of non-stick cooking pans and water resistant clothing, on the leaves of the lotus plan, or even during the protein folding process in our bodies. Hydrophobicity is directly measured by determining a contact angle between water and an objects surface. Associated with a hydrophobic surface is the depletion layer, a low density region approximately 0.2 nm thick. We study this region by comparing data found in lab using surface plasmon resonance techniques to theoretical calculations. Experiments use gold slides coated in ODT and Mercapto solutions to model both hydrophobic and hydrophilic surfaces respectively.

Direct Synthesis of Hyperbranched Poly(acrylic acid-co-3-hydroxypropionate

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Efkan Çatıker

2015-01-01

Full Text Available Hyperbranched poly(acrylic acid-co-3-hydroxypropionate (PAcHP was synthesized by base-catalyzed hydrogen transfer polymerization of acrylic acid through one step. The copolymers obtained through solution and bulk polymerization were insoluble in water and all organic solvents tried. Structural and compositional characterizations of hyperbranched PAcHP were performed by using FTIR, solid 13C-NMR, TGA, and titrimetric analysis. Acrylate fraction of the hyperbranched PAcHP obtained via bulk polymerization was determined as 60–65% by comparing TGA curves of hyperbranched PAcHP and pure poly(3-hydroxy propionate (PHP. However, analytical titration of the same sample revealed that acrylic acid units were about 47.3%. The results obtained from TGA and analytical titration were used to evaluate the chemical structure of the copolymer. Hyperbranched PAcHP exhibited hydrogel properties. Swelling behavior of the copolymer was investigated at a wide pH range and ionic strength. The dynamic swelling profiles of hyperbranched PAcHP exhibited a fast swelling behavior in the first hour and achieved the equilibrium state within 12 h in PBS. Depending on the conditions, the copolymers exhibited swelling ratios up to 2100%. As the copolymer has easily biodegradable propionate and versatile functional acrylic acid units, it can be used as not only biodegradable material in medical applications but also raw material in personal care commodities.

Radiation-induced grafting of acrylic acid onto polypropylene film and its biodegradability

Science.gov (United States)

Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Chaudhari, C. V.; Dubey, K. A.; Varshney, L.

2016-06-01

Polypropylene based commodity polyolefins are widely used in packaging, manufacturing, electrical, pharmaceutical and other applications. The aim of the present work is to study the effect of grafting of acrylic acid on the biodegradability of acrylic acid grafted polypropylene. The effect of different conditions showed that grafting percentage increased with increase in monomer concentration, radiation dose and inhibitor concentration but decreased with increase in radiation dose rate. The maximum grafting of 159.4% could be achieved at optimum conditions. The structure of grafted polypropylene films at different degree of grafting was characterized by EDS, FTIR, TGA, DSC, SEM and XRD. EDS studies showed that the increase in acrylic acid grafting percentage increased the hydrophilicity of the grafted films. FTIR studies indicated the presence of acrylic acid on the surface of polypropylene film. TGA studies revealed that thermal stability decreased with increase in grafting percentage. DSC studies showed that melting temperature and crystallinity of the grafted polypropylene films lower than polypropylene film. SEM studies indicated that increase in acrylic acid grafting percentage increased the wrinkles in the grafted films. The maximum biodegradability could be achieved to 6.85% for 90.5% grafting. This suggested that microorganisms present in the compost could biodegrade acrylic acid grafted polypropylene.

Synthesis and characterization of copolymers 4,5-dihydroisoxazole and (-)-menthyl acrylates

International Nuclear Information System (INIS)

Passo, Joel A.; Merlo, Aloir A.; Eccher, Juliana; Bechtold, Ivan H.; Kelly, Stephen M.

2012-01-01

Five monomers 5-[4-(5-cyano-4,5-dihydroisoxazol-3-yl)phenoxy]undecyl acrylate (7a); n-alkyl 3-{4-[5-(acryloyloxyundecyl)oxyphenyl]}-4,5-dihydroisoxazole-5-carboxylate (7b,c for n-butyl and n-hexyl, respectively); 3-{4-[5-(acryloyloxyundecyl) oxyphenyl]}-4,5-dihydroisoxazole-5-carboxylic acid (7d) and (1R,2S,5R)-2-isopropyl-5-methylcyclohexyl acrylate (9) and the corresponding copolymers 10a-d,11 and homopolymers 12 from 7a and 13 from 9 were designed and synthesized. Except for acrylate 9 which is derived from (-)-menthol, all of the monomers belong to the series containing the isoxazoline ring linked to the acrylate unit by a flexible spacer chain of eleven methylene units. They presented low glass temperature and despite birefringence behavior, these copolymers showed no mesomorphic properties. (author)

Electron beam curable branched chain polyurethane acrylates for magnetic media coatings

International Nuclear Information System (INIS)

Ukachi, Takashi; Haga, Kei-ichi; Matsumura, Yoshio

1989-01-01

Electron beam curable binder resins have been studied to realize the high quality magnetic coatings. It was supposed that resins with a higher crosslink density could lead to magnetic coatings with higher abrasion resistance. Branched chain polyurethane acrylates show a higher degree of cure by irradiation with an electron beam in comparison with linear polyurethane acrylates. This paper describes the potential wear resistance between properties of magnetic coatings and the physical properties of the cured unpigmented branched chain polyurethane acrylates that were used as the binder resins. (author)

Magnetic resonance imaging diagnosis of intraocular lenses. Die kernspintomographische Diagnostik der Hinterkammerlinse

Energy Technology Data Exchange (ETDEWEB)

Tosch, U. (Strahlenklinik und Poliklinik, Universitaetsklinik Rudolf Virchow, Berlin (Germany)); Bleckmann, H. (Strahlenklinik und Poliklinik, Universitaetsklinik Rudolf Virchow, Berlin (Germany)); Kaczmarek, U. (Strahlenklinik und Poliklinik, Universitaetsklinik Rudolf Virchow, Berlin (Germany))

1994-09-01

Intraocular lenses were investigated by MRI to obtain information about the quality of this method. In experimental studies, seven lenses of between 0 and 30 diopters were visualized. By MRI it was possible to differentiate the various diameters of lenses. It was not possible to discriminate the material of the intraocular lenses. After these first studies the eyes of two corpses and eight patients were investigated. Because of the resolution of MRI it was possible to tell the diopter of implanted lenses. However, by use of MRI in the regular position, a tilting or decentration of the intraocular lens was demonstrated. (orig.)

Electrochemical lysis at the stage of endoresection for large posterior intraocular tumors

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Yu. A. Belyy

2012-01-01

Full Text Available Purpose: to design the new combined technique of endoresection with intraoperative intraocular electrochemical lysis at the tumor destruction stage for large posterior intraocular tumors.Methods: 3 patients (3 eyes with large choroidal melanomas t3N0M0 (tumor thickness — 8-10 mm, base diameter — 13-15 mm, juxtapapillary localization. Mean age was 55.4 years old. Endoresection with intraoperational intraocular electrochemical lysis of the tumor was performed. Electrochemical lysis was performed with use of the technical unit ECU 300 (Soering, Germany and the original method of combined intratumoral positioning of two platinum electrodes: anode and cathode.Results: the tumor was removal completely in all 3 cases. the anatomical retinal reattachment was reached in all patients. Sclera was safe in all 3 cases. Visual acuity was not changed (NLP. At the place of the removal tumor a surgical choroidal coloboma without pigmentation all over scleral bed and periphery was shown in all cases in distant postoperative period (from 1.5 to 3 years. No local recurrences or metastasis were revealed in all patients.Conclusion: Further investigations in clinical group are necessarily to determinate the real possibilities of the combined method and the indications for endoresection with intraoperative intraocular electrochemical lysis for large intraocular tumors. 

Phacoemulsification and intraocular lens implantation in patients with oculocutaneous albinism.

Science.gov (United States)

Dávila, Pedro J; Ulloa-Padilla, Jan P; Izquierdo, Natalio J

2017-01-01

To evaluate the benefits of phacoemulsification and intraocular lens implantation in patients with oculocutaneous albinism (OCA). The charts of 195 patients with OCA who visited a local eye clinic were reviewed. All of these patients had genetic linkage analysis to establish OCA type. Frequencies and Paired t-test analysis were determined. Of the 195 patients, nine (4.6%) underwent clear cornea phacoemulsification with intraocular lens implantation. Seven of the nine patients with OCA had the Hermansky-Pudlak (HPS) type 1; two had OCA type 1. Pre-operative BCVA of all eyes ranged from 1.0 to 2.3 logMAR with a mean of 1.42 logMAR and a standard deviation of 0.41 logMAR. Post-operative BCVA of all eyes ranged from 1.0 to 1.30 logMAR with a mean of 1.04 logMAR and a standard deviation of 0.10 logMAR. BCVA improved after phacoemulsification surgery and intraocular lens implantation (p = 0.002). Pre-operative astigmatism of all eyes ranged from +0.50 to +5.75 with a mean of +2.25 and a standard deviation of +2.40. Post-operative astigmatism of all eyes ranged from +0.50 to +2.00 with a mean of +1.23 and a standard deviation of +0.42. Astigmatism improved after phacoemulsification surgery and intraocular lens implantation (p = 0.05). Nine patients with OCA who underwent phacoemulsification and intraocular lens implant experienced improved visual acuity and reduced astigmatism post-operatively. These results suggest cataract surgery may improve vision and refractive errors, and thus quality of life, in patients with albinism.

Bubble-point measurement for the binary mixture of propargyl acrylate and propargyl methacrylate in supercritical carbon dioxide

International Nuclear Information System (INIS)

Baek, Seung-Hyun; Byun, Hun-Soo

2016-01-01

Highlights: • Phase behaviours for the (CO_2 + propargyl (meth)acrylate) systems by static method were measured. • (P, x) isotherms is obtained at pressures up to 19.14 MPa and at temperature of (313.2 to 393.2) K. • The (CO_2 + propargyl acrylate) and (CO_2 + propargyl methacrylate) systems exhibit type-I behaviour. - Abstract: Acrylate and methacrylate (acrylic acid type) are compounds with weak polarity which show a non-ideal behaviour. Phase behaviour of these systems play a significant role as organic solvents in industrial processes. High pressure phase behaviour data were reported for binary mixture of propargyl acrylate and propargyl methacrylate in supercritical carbon dioxide. The bubble-point curves for the (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl methacrylate) mixtures were measured by static view cell apparatus at temperature range from 313.2 K to 393.2 K and at pressures below 19.14 MPa. The (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl methacrylate) systems exhibit type-I phase behaviour. The (carbon dioxide + (meth)acrylate) systems had continuous critical mixture curves with maximums in pressure located between the critical temperatures of carbon dioxide and propargyl acrylate or carbon dioxide and propargyl methacrylate. The solubility behaviour of propargyl (meth)acrylate in the (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl acrylate) systems increases as the temperature increases at a fixed pressure. The experimental results for the (carbon dioxide + propargyl acrylate) and (carbon dioxide + propargyl methacrylate) systems correlate with the Peng–Robinson equation of state using a van der Waals one-fluid mixing rule. The critical properties of propargyl acrylate and propargyl methacrylate were predicted with the Joback–Lyderson group contribution and Lee–Kesler method.

X-ray diffraction enhanced imaging study of intraocular tumors in human beings

International Nuclear Information System (INIS)

Tan Gao; Wang Huaqiao; Chen Yu; Yuan Qing; Li Gang; Zhu Peiping; Zhang Xiaodan; Zhong Xiufeng; Tang Jintian

2010-01-01

Diffraction enhanced imaging (DEI) with edge enhancement is suitable for the observation of weakly absorbing objects. The potential ability of the DEI was explored for displaying the microanatomy and pathology of human eyeball in this work. The images of surgical specimens from malignant intraocular tumor of hospitalized patients were taken using the hard X-rays from the topography station of Beamline 4W1A at Beijing Synchrotron Radiation Facility (BSRF). The obtained radiographic images were analyzed in correlation with those of pathology. The results show that the anatomic and pathologic details of intraocular tumors in human beings can be observed clearly by DEI for the first time, with good visualization of the microscopic details of eyeball ring such as sclera, choroid and other details of intraocular organelles. And the best resolution of DEI images reaches up to the magnitude of several tens of μm. The results suggest that it is capable of exhibiting clearly the details of intraocular tumor using DEI method. (authors)

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

OpenAIRE

Bojanić Vaso

2010-01-01

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 c...

[Hydrogen peroxide, chloramine T and chlorhexidrine in the disinfection of acrylic resin].

Science.gov (United States)

Czerwińska, W; Kedzia, A; Kałowski, M

1978-01-01

The effectiveness of 3% h drogen peroxide, 5% chloramine T and 0,5% chlorhexidine gluconate solutions in disinfection of acrylic resine plates massively infected with oral flora was analysed. The acrylic resine plates used for investigations, were infected in vitro with mixed salivary flora characterized by small numbers of yeast-like fungi (1st group), or great number of these microorganisms (2nd group). Infected plates were exposed to solutions of analysed disinfectants during various time periods. After rinsing or inactivation of disinfectant residues, acrylic plates were put into bacteriological medium and incubated during 7 days period in 37 degrees C. The results of this study indicated the effectiveness of acrylic plates disinfection to be dependent on used disinfectant, time of exposition, and microorganisms present on the surface of acrylic resine. The solutions of disinfectants were less active in the cases of plates infected with material containing great numbers of yeast-like microorganisms. Among analysed disinfectants 0,5% solution of chlorhexidine was characterized by most effective and rapid activity, whereas 3% solution of hydrogen peroxide was found to be the least effective.

Fluoroalkyl and Alkyl Chains Have Similar Hydrophobicities in Binding to the “Hydrophobic Wall” of Carbonic Anhydrase

Energy Technology Data Exchange (ETDEWEB)

J Mecinovic; P Snyder; K Mirica; S Bai; E Mack; R Kwant; D Moustakas; A Heroux; G Whitesides

2011-12-31

The hydrophobic effect, the free-energetically favorable association of nonpolar solutes in water, makes a dominant contribution to binding of many systems of ligands and proteins. The objective of this study was to examine the hydrophobic effect in biomolecular recognition using two chemically different but structurally similar hydrophobic groups, aliphatic hydrocarbons and aliphatic fluorocarbons, and to determine whether the hydrophobicity of the two groups could be distinguished by thermodynamic and biostructural analysis. This paper uses isothermal titration calorimetry (ITC) to examine the thermodynamics of binding of benzenesulfonamides substituted in the para position with alkyl and fluoroalkyl chains (H{sub 2}NSO{sub 2}C{sub 6}H{sub 4}-CONHCH{sub 2}(CX{sub 2}){sub n}CX{sub 3}, n = 0-4, X = H, F) to human carbonic anhydrase II (HCA II). Both alkyl and fluoroalkyl substituents contribute favorably to the enthalpy and the entropy of binding; these contributions increase as the length of chain of the hydrophobic substituent increases. Crystallography of the protein-ligand complexes indicates that the benzenesulfonamide groups of all ligands examined bind with similar geometry, that the tail groups associate with the hydrophobic wall of HCA II (which is made up of the side chains of residues Phe131, Val135, Pro202, and Leu204), and that the structure of the protein is indistinguishable for all but one of the complexes (the longest member of the fluoroalkyl series). Analysis of the thermodynamics of binding as a function of structure is compatible with the hypothesis that hydrophobic binding of both alkyl and fluoroalkyl chains to hydrophobic surface of carbonic anhydrase is due primarily to the release of nonoptimally hydrogen-bonded water molecules that hydrate the binding cavity (including the hydrophobic wall) of HCA II and to the release of water molecules that surround the hydrophobic chain of the ligands. This study defines the balance of enthalpic and

[Changes in intraocular pressure depending on posture].

Science.gov (United States)

Barac, Ramona; Pop, Monica; Tătaru, C; Gheorghe, A; Bădescu, Silvia; Stanciu, Maria; Burcea, M

2014-01-01

Glaucoma is an important eye disease that, left untreated, causes irreversible blindness by affecting optic nerve threads. Decreasing intraocular pressure and maintaining it at a low level throughout the day is one of the objectives of antiglaucoma therapy. This is a prospective study conducted on a sample of 80 patients who presented at "Emergency Eye Hospital" Bucharest between 1st of December 2013 30th of July 2014. Patients were divided into two groups: 40 patients with glaucoma and 40 patients without glaucoma (control group). THE OBJECTIVE OF THE STUDY: To determine changes in intraocular pressure that may occur depending on body posture and the correlations between changes in intraocular pressure and glaucoma, obesity, hypertension. These IOP changes may be important in the progression of glaucoma regarding that one third of our time is spent on supine position during night. RESULTS AND CONCLUZIONS: IOP varies from sitting down to supine position. IOP increases in supine in most patients (with or without glaucoma) with an average of 1.25 mmHg. The increase among patients with glaucoma is higher (1.67 mmHg) compared to those without glaucoma (0.82 mmHg). In patients with hypertension and glaucoma, IOP increased with 2.62 mmHg. In patients with hypertension and obesity IOP increased with 2.5 mmHg.

Near-infrared transillumination photography of intraocular tumours.

Science.gov (United States)

Krohn, Jørgen; Ulltang, Erlend; Kjersem, Bård

2013-10-01

To present a technique for near-infrared transillumination imaging of intraocular tumours based on the modifications of a conventional digital slit lamp camera system. The Haag-Streit Photo-Slit Lamp BX 900 (Haag-Streit AG) was used for transillumination photography by gently pressing the tip of the background illumination cable against the surface of the patient's eye. Thus the light from the flash unit was transmitted into the eye, leading to improved illumination and image resolution. The modification for near-infrared photography was done by replacing the original camera with a Canon EOS 30D (Canon Inc) converted by Advanced Camera Services Ltd. In this camera, the infrared blocking filter was exchanged for a 720 nm long-pass filter, so that the near-infrared part of the spectrum was recorded by the sensor. The technique was applied in eight patients: three with anterior choroidal melanoma, three with ciliary body melanoma and two with ocular pigment alterations. The good diagnostic quality of the photographs made it possible to evaluate the exact location and extent of the lesions in relation to pigmented intraocular landmarks such as the ora serrata and ciliary body. The photographic procedure did not lead to any complications. We recommend near-infrared transillumination photography as a supplementary diagnostic tool for the evaluation and documentation of anteriorly located intraocular tumours.

Acrylic Triblock Copolymers Incorporating Isosorbide for Pressure Sensitive Adhesives

Energy Technology Data Exchange (ETDEWEB)

Gallagher, James J.; Hillmyer, Marc A.; Reineke, Theresa M. (UMM)

2016-05-10

A new monomer acetylated acrylic isosorbide (AAI) was prepared in two steps using common reagents without the need for column chromatography. Free radical polymerization of AAI afforded poly(acetylated acrylic isosorbide) (PAAI), which exhibited a glass transition temperature (Tg) = 95 °C and good thermal stability (Td, 5% weight loss; N2 = 331 °C, air = 291 °C). A series of ABA triblock copolymers with either poly(n-butyl acrylate) (PnBA) or poly(2-ethylhexyl acrylate) (PEHA) as the low Tg midblocks and PAAI as the high Tg end blocks were prepared using Reversible Addition–Fragmentation chain Transfer (RAFT) polymerization. The triblock copolymers ranging from 8–24 wt % PAAI were evaluated as pressure sensitive adhesives by 180° peel, loop tack, and static shear testing. While the PAAI-PEHA-PAAI series exhibited poor adhesive qualities, the PAAI-PnBA-PAAI series of triblock copolymers demonstrated peel forces up to 2.9 N cm–1, tack forces up to 3.2 N cm–1, and no shear failure up to 10000 min. Dynamic mechanical analysis indicated that PAAI-PEHA-PAAI lacked the dissipative qualities needed to form an adhesive bond with the substrate, while the PAAI-PnBA-PAAI series exhibited a dynamic mechanical response consistent with related high performing PSAs.

Homogeneous synthesis of cellulose acrylate-g-poly (n-alkyl acrylate) solid-solid phase change materials via free radical polymerization.

Science.gov (United States)

Qian, Yong-Qiang; Han, Na; Bo, Yi-Wen; Tan, Lin-Li; Zhang, Long-Fei; Zhang, Xing-Xiang

2018-08-01

A novel solid-solid phase change materials, namely, cellulose acrylate-g-poly (n-alkyl acrylate) (CA-g-PAn) (n = 14, 16 and 18) were successfully synthesized by free radical polymerization in N, N-dimethylacetamide (DMAc). The successful grafting was confirmed by fourier transform infrared spectra (FT-IR) and nuclear magnetic resonance (NMR). The properties of the CA-g-PAn copolymers were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). The phase change temperatures and the melting enthalpies of CA-g-PAn copolymers are in the range of 10.1-53.2 °C and 15-95 J/g, respectively. It can be adjusted by the contents of poly (n-alkyl acrylate) and the length of alkyl side-chain. The thermal resistant temperatures of CA-g-PA14, 16 and 18 copolymers are 308 °C, 292 °C and 273 °C, respectively. It show that all of grafting materials exhibit good thermal stability and shape stability. Therefore, it is expected to be applied in the cellulose-based thermos-regulating field. Copyright © 2018 Elsevier Ltd. All rights reserved.

Intraocular pressure measurement: Goldmann Applanation Tonometer vs non contact airpuff tonometer.

Science.gov (United States)

Shah, Masood Alam; Bin Saleem, Khalid; Mehmood, Talat

2012-01-01

An accurate assessment of Intraocular pressure (IOP) is vital in establishing diagnosis of Glaucoma and decision making regarding various treatment modalities available. The purpose of this study is to compare Goldmann Applanation Tonometer (GAT) with Air puff tonometer. Cross-sectional comparative study conducted. 73 eyes from 73 patients were included in this study and intraocular pressure (IOP) was measured by GAT and PT100 at Sheikh Khalifa Bin Zayed Hospital, Muzaffarabad, Benazir Shaheed Teaching Hospital, Abbottabad. Mean age of the patients was 53.17 +/- 13.80 years. Mean IOP measurements showed significant differences in measurements performed by the two tonometers (p contact air-puff tonometer, the Goldmann applanation tonometer is a reliable and consistent technique for measurement of intraocular pressure.

Allergic contact dermatitis from sculptured acrylic nails: special presentation with an airborne pattern

Science.gov (United States)

Maio, Paula; Carvalho, Rodrigo; Amaro, Cristina; Santos, Raquel; Cardoso, Jorge

2012-01-01

Methylmethacrylate was first reported in 1941 as a cause of contact dermatitis. Since then, occupational contact allergies to acrylates in dentistry, orthopedic surgery, printing industry and industry have been reported, but few reports are found in the literature as a consequence of the contact with sculptured artificial acrylic nails which are increasingly popular. We describe here 3 patients with contact allergy to acrylates in artificial sculptured nails. Patch tests were performed with the Portuguese baseline series of contact allergens and an extended series of acrylates were applied. In particular, we tested three female patients with allergic contact dermatitis from sculptured acrylic nails. Two of these patients were both customers and also technical nail beauticians. Two patients developed periungual eczema; one presented only with face and eyelid dermatitis had no other lesions. The tests showed positive reaction to 2-hydroxyethylmethacrylate (2-HEMA) and 2-hydroxypropylmethacrylate (2-HPMA) in all the three patients. Our cases demonstrate the variety of clinical presentations of allergic contact dermatitis from acrylic sculptured nails. They show the need to warn patients of persistent and sometimes permanent side effects of these products. They also emphasize the importance of cosmetic ingredient labeling. PMID:25386316

Acrylic composition

International Nuclear Information System (INIS)

Kimura, Tadashi; Ozeki, Takao; Kobayashi, Juichi; Nakamoto, Hideo; Meda, Yutaka.

1969-01-01

An acrylic composition and a process for the production of an easily hardenable coating material by irradiating with active energy, particularly electron beams and ultraviolet light, are provided using a mixture of 10%-100% by weight of an unsaturated compound and 90%-0% of a vinyl monomer. The composition has a high degree of polymerization, low volatility, low viscosity and other properties similar to thermosetting acrylic or amino alkyd resins. The aforesaid unsaturated compound is produced by primarily reacting saturated cyclocarboxylic anhydride and/or alpha-, beta-ethylene unsaturated carboxylic anhydride and by secondarily reacting an epoxy radical-containing vinyl monomer by addition reaction with polyhydric alcohols. Each reaction is conducted in the presence of a tertiary amino radical-containing vinyl monomer as a catalyst. The cross-linking is effected generally with an electron beam accelerator of 0.1-2.0 MeV or with a light beam in the 2,000-8,000A range in the presence of a photosensitive agent. In one example, 62 parts of ethylene glycol and 196 parts of maleic anhydride were dissolved in a mixture consisting of 100 parts of n-butyl methacrylate and 30 parts of styrene. To the mixture were added 5 parts of 2-methyl 5 vinyl piridine and 0.005 part of hydroquinone monomethyl ether. After the reaction at 90 0 C for 3 hours, a compound HOC:O-CH=CHC:OCH 2 CH 2 C:OOH was produced. To this solution were added 285 parts of glycidyl methacrylate. After the reaction at 90 0 C for 6 hours, 95% of the carboxylic acids reacted with epoxy radicals. Fourteen examples are given. (Iwakiri, K.)

Surface morphology changes of acrylic resins during finishing and polishing phases

Directory of Open Access Journals (Sweden)

Glaucio Serra

2013-12-01

Full Text Available INTRODUCTION: The finishing and polishing phases are essential to improve smoothness and shining on the surface of acrylic resins used to make removable orthodontic appliances. A good surface finishing reduces roughness, which facilitates hygiene, prevents staining and provides greater comfort to the patients. OBJECTIVE: The aim of this paper was to analyze the changes on surface morphology of acrylic resins during finishing and polishing phases. METHODS: Thirty discs (10 mm in diameter and 5 mm in length were made with acrylic resin and randomly divided into ten groups. The control group did not receive any treatment while the other groups received gradual finishing and polishing. The last group received the entire finishing and polishing procedures. Surface morphology was qualitatively analyzed through scanning electron microscopy and quantitatively analyzed through a laser profilometer test. RESULTS: The acrylic resin surfaces without treatment showed bubbles which were not observed in the subsequent phases. Wearing out with multilaminated burs, finishing with wood sandpaper and finishing with water sandpaper resulted in surfaces with decreasing irregularities. The surfaces that were polished with pumice and with low abrasive liquids showed high superficial smoothness. CONCLUSION: Highly smooth acrylic resin surfaces can be obtained after mechanical finishing and polishing performed with multilaminated burs, wood sandpaper, water sandpaper, pumice and low abrasive liquids.

Ocular onchocerciasis in the Yanomami communities from Brazilian Amazon: effects on intraocular pressure.

Science.gov (United States)

Herzog-Neto, Guilherme; Jaegger, Karen; Nascimento, Erika S do; Marchon-Silva, Verônica; Banic, Dalma M; Maia-Herzog, Marilza

2014-01-01

To determine the influence of onchocercal eye disease on the intraocular pressure of the Yanomami Tribe Aratha-ú of Roraima State, Brazil, considered endemic for onchocerciasis, a total of 86 patients were submitted to an ophthalmologic exam that included external examination, slit lamp examination, intraocular pressure measurement, and a fundus ophthalmoscope examination. A high prevalence of onchocerciasis-related eye lesions was encountered in 68.6% of the patients. Punctate keratitis and microfilariae in the anterior chamber were found in ∼28%. The mean of intraocular eye pressure found was 10.47 mm of Hg.

Sensitivity of the corneal-plane refractive compensation to change in power and axial position of an intraocular lens

Directory of Open Access Journals (Sweden)

W. F. Harris

2009-12-01

Full Text Available If an intraocular lens is displaced or if its power is changed what are the consequences for the refractive compensation of the eye?  Gaussian optics is used to obtain explicit formulae for the sensitivityof the corneal-plane refractive compensation (also called the refraction, refractive state, etc to change in power and axial displacement of a thin intraocular lens implanted in a simple eye.  In particular, for a pseudophakic Gullstrand simplified eye with intraocular lens placed 5 mm behind the cornea the sensitivity to errors in the power of the intraocular lens is about  71 . 0 − 71 for an intraocular lens of power   for an intraocular lens of power 20 D, that is, the refractive compensation decreases by about 0.71 dioptres per dioptre increase in the power of the intraocular lens.  More generally the sensitivity is approximately  ( m   0037 . 0 63 . 0 F − − 0.63 ( 003 . 0 63 . 0 − − (0.0037mF where FI is the power of the intraocular lens.  Also for Gullstrand’s simplified eye the sensitivity of refractive compensation to axial displacement of the intraocular lens is approximately linear in FI about  (64D FI, in fact.  That is, for each dioptre of the power of the intraocular lens the refractive compensation increases by about 0.064 dioptres per millimetre of axial displacement towards the retina. 

Intraocular Pressure Increases After Intraarticular Knee Injection With Triamcinolone but Not Hyaluronic Acid.

Science.gov (United States)

Taliaferro, Kevin; Crawford, Alexander; Jabara, Justin; Lynch, Jonathan; Jung, Edward; Zvirbulis, Raimonds; Banka, Trevor

2018-03-09

Intraarticular steroid injections are a common first-line therapy for severe osteoarthritis, which affects an estimated 27 million people in the United States. Although topical, oral, intranasal, and inhalational steroids are known to increase intraocular pressure in some patients, the effect of intraarticular steroid injections on intraocular pressure has not been investigated, to the best of our knowledge. If elevated intraocular pressure is sustained for long periods of time or is of sufficient magnitude acutely, permanent loss of the visual field can occur. How does intraocular pressure change 1 week after an intraarticular knee injection either with triamcinolone acetonide or hyaluronic acid? A nonrandomized, nonblinded prospective cohort study was conducted at an outpatient, ambulatory orthopaedic clinic. This study compared intraocular pressure elevation before and 1 week after intraarticular knee injection of triamcinolone acetonide versus hyaluronic acid for management of primary osteoarthritis of the knee. Patients self-selected to be injected in their knee with either triamcinolone acetonide or hyaluronic acid before being informed of the study. The primary endpoint was intraocular pressure elevation of ≥ 7 mm Hg 1 week after injection. This cutoff is determined as the minimum significant pressure change in the ophthalmology literature recognized as an intermediate responder to steroids. Intraocular pressure was measured using a handheld Tono-Pen® applanation device. This device is frequently used in intraocular pressure measurement in clinical and research settings; 10 sequential measurements are obtained and averaged with a confidence interval. Only measurements with a 95% confidence interval were used. Over a 6-month period, a total of 96 patients were approached to enroll in the study. Sixty-two patients out of 96 approached (65%) agreed. Thirty-one (50%) were injected with triamcinolone and 31 (50%) were injected with hyaluronic acid. Patients

Polyurethane acrylate networks including cellulose nanocrystals: a comparison between UV and EB- curing

Science.gov (United States)

Furtak-Wrona, K.; Kozik-Ostrówka, P.; Jadwiszczak, K.; Maigret, J. E.; Aguié-Béghin, V.; Coqueret, X.

2018-01-01

A water-based polyurethane (PUR) acrylate water emulsion was selected as a radiation curable matrix for preparing nanocomposites including cellulose nanocrystals (CNC) prepared by controlled hydrolysis of Ramie fibers. Cross-linking polymerization of samples prepared in the form of films or of 1 mm-thick bars was either initiated by exposure to the 395 nm light of a high intensity LED lamp or by treatment with low energy electron beam (EB). The conversion level of acrylate functions in samples submitted to increasing radiation doses was monitored by Fourier Transform Infrared Spectroscopy (FTIR). Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) were used to characterize changes in the glass transition temperature of the PUR-CNC nanocomposites as a function of acrylate conversion and of CNC content. Micromechanical testing indicates the positive effect of 1 wt% CNC on Young's modulus and on the tensile strength at break (σ) of cured nanocomposites. The presence of CNC in the PUR acrylate matrix was shown to double the σ value of the nanocomposite cured to an acrylate conversion level of 85% by treatment with a 25 kGy dose under EB, whereas no increase of σ was observed in UV-cured samples exhibiting the same acrylate conversion level. The occurrence of grafting reactions inducing covalent linkages between the polysaccharide nanofiller and the PUR acrylate matrix during the EB treatment is advanced as an explanation to account for the improvement observed in samples cured under ionizing radiation.

21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

Science.gov (United States)

2010-04-01

... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl acrylate...

Alkyd-acrylic hybrid systems for use as binders in waterborne paints

NARCIS (Netherlands)

Nabuurs, T.; Baijards, R.A.; German, A.L.

1994-01-01

Alkyd-acrylic hybrids were prepd. by polymg. the acrylic monomers in the presence of colloidal alkyd droplets. Polymn. in the presence of alkyd caused a retardation of the polymn. through radical delocalization following radical transfer to the unsatd. groups of the fatty acids in the alkyd. The

Intraocular gnathostomiasis: report of a case and review of literature.

Science.gov (United States)

Pillai, Gopal S; Kumar, Anil; Radhakrishnan, Natasha; Maniyelil, Jayasree; Shafi, Tufela; Dinesh, Kavitha R; Karim, Shamsul

2012-04-01

Intraocular gnathostomiasis is a rare parasitic infection caused by the third-stage larvae of spiruroid nematode Gnanthostoma spp. seen mostly in tropical and subtropical regions. It is a food-borne zoonosis caused by ingestion of raw or undercooked freshwater fish, amphibians, reptiles, birds, and mammals, all of which are known to harbor advanced third-stage larvae of Gnanthostoma spp. To date, 74 cases of intraocular gnathostomiasis have been reported from 12 different countries. Only four countries have reported more than 10 cases each, and India shares the rare distinction of being one of them, with 14 cases. Surprisingly, not a single case of cutaneous gnanthostomiasis has ever been reported from India. We present one such case of intraocular gnathostomiasis in a 41-year-old male who presented with an actively motile worm attached to the iris, and we review the pertinent literature of all such cases reported from India.

Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber

OpenAIRE

Jamil, Siti Nurul Ain Md; Daik, Rusli; Ahmad, Ishak

2014-01-01

A synthesis of acrylonitrile (AN)/butyl acrylate (BA)/fumaronitrile (FN) and AN/EHA (ethyl hexyl acrylate)/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS) and potassium persulphate (KPS) as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (Tg) and stabilization temperature was studied using Differential Scanning Calorimetry (DSC). The degradation behavior and char yield were obtained by Thermog...

21 CFR 584.700 - Hydrophobic silicas.

Science.gov (United States)

2010-04-01

...) Product. Amorphous fumed hydrophobic silica or precipitated hydrophobic silica (CAS Reg. No. 68611-0944... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Hydrophobic silicas. 584.700 Section 584.700 Food... DRUGS, FEEDS, AND RELATED PRODUCTS FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE IN FEED AND...

Adsorption of Hydrophobically Modified Polyelectrolytes on Hydrophobic Substrates Adsorption de polyélectrolytes modifiés hydrophobiquement sur les substrats hydrophobes

Directory of Open Access Journals (Sweden)

Mays J. W.

2006-12-01

Full Text Available A series of diblock copolymers, poly (tert-butyl styrene-sodium poly (styrene sulfonate with different molecular weight and percentage of sulfonation have been used to study the effect of polymer structure on its adsorption behavior onto hydrophobically modified silicon wafers. The percentage of the hydrophobic block varies from 3. 6-8. 9%. Previous studies show that salt concentration is very important for the adsorption of such polyelectrolytes onto silica surfaces. Octadecyltriethoxysilane (OTE has been used to modify the silicon wafer which changes the water contact angle from 50° on unmodified silica to 100° to 120°. On this hydrophobic surface, we found that the adsorption of these slightly hydrophobically modified polyelectrolytes is close to the 4/23rd power of salt concentration predicted by a recent model. The grafting density is also consistent with a dependence on the length of the hydrophobic block to the -12/23rd power, and the length of the polyelectrolyte block to the -6/23rd power, predicted by this model. Une série de copolymères à diblocs poly (tert-butyle styrène-sodium (sulfonate de polystyrène de masses moléculaires et pourcentages de sulfonation différents ont été utilisés pour étudier les effets de la structure du polymère sur son pouvoir d'adsorption sur des surfaces de silicium modifiées hydrophobiquement. Le pourcentage du bloc hydrophobe varie de 3,6 à 8,9%. Les études antérieures montrent que la concentration saline est très importante pour l'adsorption de ces polyélectrolytes sur les surfaces de silice. Nous avons utilisé l'octadecyltriéthoxysilane (OTE pour modifier la surface de silicium qui change l'angle de contact de l'eau de 50° sur la silice non modifiée à une valeur comprise entre 100° et 120° sur la silice modifiée. Sur cette surface hydrophobe, nous constatons que l'adsorption de ces polyélectrolytes légèrement modifiés hydrophobiquement est proche de la loi puissance 4

Surface analysis of selected hydrophobic materials

Science.gov (United States)

Wisniewska, Sylwia Katarzyna

This dissertation contains a series of studies on hydrophobic surfaces by various surface sensitive techniques such as contact angle measurements, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Hydrophobic surfaces have been classified as mineral surfaces, organic synthetic surfaces, or natural biological surfaces. As a model hydrophobic mineral surface, elemental sulfur has been selected. The sulfur surface has been characterized for selected allotropic forms of sulfur such as rhombic, monoclinic, plastic, and cyclohexasulfur. Additionally, dextrin adsorption at the sulfur surface was measured. The structure of a dextrin molecule showing hydrophobic sites has been presented to support the proposed hydrophobic bonding nature of dextrin adsorption at the sulfur surface. As a model organic hydrophobic surface, primary fatty amines such as dodecylamine, hexadecylamine, and octadecylamine were chosen. An increase of hydrophobicity, significant changes of infrared bands, and surface topographical changes with time were observed for each amine. Based on the results it was concluded that hydrocarbon chain rearrangement associated with recrystallization took place at the surface during contact with air. A barley straw surface was selected as a model of biological hydrophobic surfaces. The differences in the contact angles for various straw surfaces were explained by the presence of a wax layer. SEM images confirmed the heterogeneity and complexity of the wax crystal structure. AFM measurements provided additional structural details including a measure of surface roughness. Additionally, straw degradation as a result of conditioning in an aqueous environment was studied. Significant contact angle changes were observed as soon as one day after conditioning. FTIR studies showed a gradual wax layer removal due to straw surface decomposition. SEM and AFM images revealed topographical changes and biological

Sutureless Intrascleral Fixated Intraocular Lens Implantation.

Science.gov (United States)

Karadag, Remzi; Celik, Haci Ugur; Bayramlar, Huseyin; Rapuano, Christopher J

2016-08-01

To review sutureless intrascleral intraocular lens (IOL) fixation methods. Review of published literature. Sutureless intrascleral IOL fixation methods are newer and have been developed to eliminate the suture-related complications of sutured scleral fixation methods such as suture-induced inflammation or infection and IOL dislocation or subluxation due to suture degradation or suture breakage. Sutureless intrascleral fixation methods aim for intrascleral haptic fixation to achieve stability of the IOL. Various methods of sutureless scleral fixation have been described. Using a needle, a blade, or a trochar, sclerostomies are created in all techniques for intraocular access. Some surgeons prefer to create scleral tunnels, whereas others use scleral flaps for scleral fixation of haptics. The stability of IOLs is attained by the scar tissue formed around the haptics. Short-term results of these new methods are acceptable; studies including more cases with longer follow-up are needed to determine their long-term success. [J Cataract Refract Surg. 2016;32(9):586-597.]. Copyright 2016, SLACK Incorporated.

The transverse strength of acrylic resin after Coleus amboinicus, Lour extract solution immersion

Directory of Open Access Journals (Sweden)

Devi Rianti

2006-12-01

Full Text Available A laboratoric experimental study was conducted on the transverse strength of acrylic resin after Coleus amboinicus, Lour extract solution immersion. The aim of this study is to know the difference of acrylic resin transverse strengths caused by immersion time variations in a concentrate solution. The study was carried out on unpolished acrylic resin plates with 65 × 10 × 2,5 mm dimension; solution with 15% Coleus amboinicus, Lour extract, and 30, 60, 90 days immersion times to measure the transverse strength and sterilized aquadest was used as control. Acrylic resin plates transverse strength was measured using Autograph AG-10 TE. The data was analyzed using One-Way Anova and LSD with 5% degree of significance. The result showed that longer immersion time will decrease the transverse strength of the acrylic resin plates. After 90 days immersion time, the transverse strength decrease is still above the recommended standard transverse strength.

Polyurethane acrylate networks including cellulose nanocrystals: a comparison between UV and EB- curing

International Nuclear Information System (INIS)

Furtak-Wrona, K.; Kozik-Ostrówka, P.; Jadwiszczak, K.; Maigret, J.E.; Aguié-Béghin, V.; Coqueret, X.

2018-01-01

A water-based polyurethane (PUR) acrylate water emulsion was selected as a radiation curable matrix for preparing nanocomposites including cellulose nanocrystals (CNC) prepared by controlled hydrolysis of Ramie fibers. Cross-linking polymerization of samples prepared in the form of films or of 1 mm-thick bars was either initiated by exposure to the 395 nm light of a high intensity LED lamp or by treatment with low energy electron beam (EB). The conversion level of acrylate functions in samples submitted to increasing radiation doses was monitored by Fourier Transform Infrared Spectroscopy (FTIR). Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) were used to characterize changes in the glass transition temperature of the PUR-CNC nanocomposites as a function of acrylate conversion and of CNC content. Micromechanical testing indicates the positive effect of 1 wt% CNC on Young's modulus and on the tensile strength at break (σ) of cured nanocomposites. The presence of CNC in the PUR acrylate matrix was shown to double the σ value of the nanocomposite cured to an acrylate conversion level of 85% by treatment with a 25 kGy dose under EB, whereas no increase of σ was observed in UV-cured samples exhibiting the same acrylate conversion level. The occurrence of grafting reactions inducing covalent linkages between the polysaccharide nanofiller and the PUR acrylate matrix during the EB treatment is advanced as an explanation to account for the improvement observed in samples cured under ionizing radiation. - Highlights: • Nanocomposites were prepared from o/w PUR acrylate emulsion and CNC suspension. • Nanocomposite and reference materials were cured to the same conversion by UV or EB. • Introducing 1 wt% CNC in EB-cured composites doubles the tensile strength. • UV-cured nanocomposites did not show significant improvement in tensile strength.

Crystal structure transformation in potassium acrylate

Science.gov (United States)

Pai Verneker, V. R.; Vasanthakumari, R.

1983-10-01

Potassium acrylate undergoes a reversible phase transformation around 335°K with an activation energy of 133 kcal/mole. Differential scanning calorimetry and high temperature X-ray powder diffraction techniques have been used to probe this phenomenon.

Microscopic and spectroscopic investigation of an explanted opacified intraocular lens

Energy Technology Data Exchange (ETDEWEB)

Simon, V., E-mail: viosimon@phys.ubbcluj.ro [Babeş-Bolyai University, Faculty of Physics and Interdisciplinary Research Institute on Bio-Nano-Sciences, 400084 Cluj-Napoca (Romania); Radu, T.; Vulpoi, A. [Babeş-Bolyai University, Faculty of Physics and Interdisciplinary Research Institute on Bio-Nano-Sciences, 400084 Cluj-Napoca (Romania); Rosca, C. [Optilens Clinic of Ophthalmology, 400604 Cluj-Napoca (Romania); Eniu, D. [Iuliu Haţieganu University of Medicine and Pharmacy, Department of Molecular Sciences, 400349 Cluj-Napoca (Romania)

2015-01-15

Highlights: • Changes on intraocular lens (IOL) surface after implantation. • Partial opacification of IOL central area. • Elemental composition on IOL surface prior to and after implantation. • First XPS depth profiling examination of the opacifying deposits. • Cell-mediated hydroxyapatite structuring. - Abstract: The investigated polymethylmethacrylate intraocular lens explanted an year after implantation presented a fine granularity consisting of ring-like grains of about 15 μm in diameter. In order to evidence the changes occurred on intraocular lens relative to morphology, elemental composition and atomic environments, microscopic and spectroscopic analyses were carried out using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), energy-dispersive X-ray (EDS), and X-ray photoelectron (XPS) spectroscopies. The results revealed that the grains contain hydroxyapatite mineral phase. A protein layer covers the lens both in opacified and transparent zones. The amide II band is like in basal epithelial cells. The shape and size of the grains, and the XPS depth profiling results indicate the possibility of a cell-mediated process involving lens epithelial cells which fagocitated apoptotic epithelial cells, and in which the debris derived from cell necrosis were calcified. To the best of our knowledge, this is the first investigation on explanted intraocular lenses using XPS depth profiling in order to examine the inside of the opacifying deposits.

In situ reactive compatibilization of natural rubber/acrylic-bentonite composites via peroxide-induced vulcanization

International Nuclear Information System (INIS)

Fu, Lihua; Lei, Zhiwen; Xu, Chuanhui; Chen, Yukun

2016-01-01

To achieve good interfacial interaction between fillers and rubber matrix is always a hot topic in rubber reinforcing industry. In this paper, acid activated bentonite (Bt) was alkalified to be alkaline calcium-bentonite (ACBt), then acrylic acid (AA) was employed to modify ACBt to obtain acrylic-bentonite (ABt). The results of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) illustrated that acrylate groups were chemically boned onto the surface of Bt and the layer spacing of Bt was increased. During peroxide-induced vulcanization, in situ compatibilization of ABt was realized via the reaction between the unsaturated bonds of acrylate groups on the surface of Bt and the natural rubber (NR) chains. This resulted in an enhanced cross-linked network which contributed to the improved mechanical properties of NR/ABt composites. - Highlights: • Acrylate groups were chemically boned onto the surface of bentonite. • In situ compatibilization was realized via the reaction of acrylate group and NR. • ABt particles participated in forming the NR crosslink network. • A potential reinforcing material options for “white” rubber products.

In situ reactive compatibilization of natural rubber/acrylic-bentonite composites via peroxide-induced vulcanization

Energy Technology Data Exchange (ETDEWEB)

Fu, Lihua; Lei, Zhiwen [Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Xu, Chuanhui, E-mail: xuhuiyee@gxu.edu.cn [Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Chen, Yukun, E-mail: cyk@scut.edu.cn [The Key Laboratory of Polymer Processing Engineering, Ministry of Education, China(South China University of Technology), Guangzhou, 510640 (China)

2016-02-15

To achieve good interfacial interaction between fillers and rubber matrix is always a hot topic in rubber reinforcing industry. In this paper, acid activated bentonite (Bt) was alkalified to be alkaline calcium-bentonite (ACBt), then acrylic acid (AA) was employed to modify ACBt to obtain acrylic-bentonite (ABt). The results of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) illustrated that acrylate groups were chemically boned onto the surface of Bt and the layer spacing of Bt was increased. During peroxide-induced vulcanization, in situ compatibilization of ABt was realized via the reaction between the unsaturated bonds of acrylate groups on the surface of Bt and the natural rubber (NR) chains. This resulted in an enhanced cross-linked network which contributed to the improved mechanical properties of NR/ABt composites. - Highlights: • Acrylate groups were chemically boned onto the surface of bentonite. • In situ compatibilization was realized via the reaction of acrylate group and NR. • ABt particles participated in forming the NR crosslink network. • A potential reinforcing material options for “white” rubber products.

Intravitreal triamcinolone for intraocular inflammation and associated macular edema

Directory of Open Access Journals (Sweden)

Steven M Couch

2008-11-01

Full Text Available Steven M Couch, Sophie J BakriMayo Clinic Department of Ophthalmology, Mayo Clinic, Rochester, MN, USAAbstract: Triamcinolone acetonide (TA is a corticosteroid that has many uses in the treatment of ocular diseases because of its potent anti-inflammatory and anti-permeability actions. Intraocular inflammation broadly referred to as uveitis can result from several causes, including the immune system and after ophthalmic surgery. One of the most common reasons for vision loss with uveitis is macular edema. TA has been used for many years as an intravitreal injection for the treatment of ocular diseases. Several case control studies have been reported showing the efficacy of TA in the treatment of intraocular inflammation and associated macular edema caused by Behcet’s disease, Vogt-Koyanagi-Harada syndrome, sympathetic ophthalmia and white dot syndromes. It has also been shown efficacious in cases of pars planitis and idiopathic posterior uveitis. Some authors have reported its use in postoperative cystoid macular edema. Many of the studies on the use of TA in controlling intraocular inflammation and concomitant macular edema showed its effect to be transient in many patients requiring reinjection. Complications can arise from intravitreal injection of TA including elevated intraocular pressure and cataract. Rarely, it can be associated with infectious and non-infectious endophthalmitis. TA may be useful as an adjuvant in the treatment of uveitis and its associated macular edema, especially in patients resistant or intolerant to standard treatment.Keywords: triamcinolone acetonide, Behcet’s disease, sympathetic ophthalmia, Vogt-Koyanagi-Harada syndrome, white dot syndromes, uveitis, cataract surgery, macular edema, endophthalmitis

Intraocular lens fabrication

Energy Technology Data Exchange (ETDEWEB)

Salazar, Mike A. (Albuquerque, NM); Foreman, Larry R. (Los Alamos, NM)

1997-01-01

This invention describes a method for fabricating an intraocular lens made rom clear Teflon.TM., Mylar.TM., or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube.

Outcomes and Complications of Scleral-Fixated Intraocular Lens Combined with Ahmed Tube Surgery

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Nikhel Sachdev

2018-01-01

Full Text Available Background. To evaluate the outcome and complications of transscleral suture-fixated posterior chamber intraocular lens (PCIOL implantation combined with Ahmed glaucoma valve (AGV surgery in Asian eyes. Design. This was a retrospective study that included 22 eyes from 22 participants. The surgeries were performed at Singapore’s National University Hospital. Participants underwent an Ahmed tube surgery, together with transscleral suture-fixated posterior chamber intraocular lens. Main Outcome Measures. Complete success was defined as 6 ≤ intraocular pressure (IOP ≤ 21 mmHg without medications at the last follow-up visit, with no reoperation required and no progression to no perception of light (NPL. Results. At the last follow-up, there was a significant reduction in mean IOP (22.4 ± 6.5 mmHg versus 13.9 ± 3.9 mmHg; p<0.001 and mean number of intraocular pressure-lowering medications (2.45 ± 1.30 versus 0.05 ± 0.21; p<0.001. There was no significant change in visual acuity [1.43 ± 1.21 (LogMAR versus 1.09 ± 1.31 (p=0.204]. Sixteen eyes (72.7% achieved complete success. The 3 commonest complications were bullous keratopathy, choroidal detachment, and displacement of intraocular lens. Conclusion and Relevance. This technique showed good success for intraocular pressure control and vision preservation. Postoperative complications were relatively common although most were self-limiting. Patients at increased risk of trabeculectomy failure may be suitable for this procedure.

Intraocular foreign-body hazard during vitrectomy.

Science.gov (United States)

Bovino, J A; Marcus, D F

1982-03-01

We noted two instances of forceps-induced fragmentation of the bar used for scleral plug storage during vitreous surgery. The silicone bar material was adherent to the plug in both cases. Because this represents a significant intraocular foreign body hazard, the scleral plug should be carefully inspected before insertion.

Effect of microwave cured acrylic resin on candidal growth in complete denture

International Nuclear Information System (INIS)

Rasmy, A.H.M.

2009-01-01

This study was conducted to evaluate the effect of heat-cured acrylic resin denture base and microwave-cured acrylic resin denture base on candidal growth . Seven completely edentulous male patients with on history of denture wearing participated in this study. all the selected patients were re-habilitated by mucosa supported complete dentures .The dentures were constructed from conventional heat-cured acrylic resin denture base following monoplane concept of occlusion. Before dismissing the patients and one month after denture insertion, salivary samples were collected according to oral rinse technique. one month resting period was allowed so as candidal count can reach to normal, then dentures were re based using microwave-cured acrylic denture base, before denture insertion and one month after denture insertion, salivary sample were collected before and one month following the same oral rinse technique.

Recovery of Acrylic Acid Using Calcium Peroxide Nanoparticles: Synthesis, Characterisation, Batch Study, Equilibrium, and Kinetics

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B. S. De

2018-03-01

Full Text Available Recovery of acrylic acid from aqueous solution using low-cost CaO2 nanoparticles was investigated. CaO2 nanoparticles were synthesized by co-precipitation technique and characterised using XRD and FTIR. A mechanism was proposed for adsorption of acrylic acid onto CaO2 nanoparticles based on FTIR analysis. Acrylic acid recovery is highly dependent on contact time, CaO2 nanoparticle dosage, initial acrylic concentration, and temperature. Langmuir, Freundlich, Dubinin-Radushkevich, Tempkin, Hill, Redlich-Peterson, Sips and Toth isotherms were used and well represented by Redlich-Peterson isotherm (R2 = 0.9998 as compared to other isotherms. Kinetic studies revealed pseudo-second-order kinetics (k2 = 1.962·10–4 g mg–1 min–1 for adsorption of acrylic acid onto CaO2 nanoparticles. CaO2 nanoparticles exhibited high acrylic acid recovery over varied concentration ranges. The acrylic acid can be regenerated by desorption from the surface of adsorbent and utilised for numerous applications. The presented results may be useful for the design of adsorption system using nanoparticles, which can be extended to other systems.

High-impact strength acrylic denture base material processed by autoclave.

Science.gov (United States)

Abdulwahhab, Salwan Sami

2013-10-01

To investigate the effect of two different cycles of autoclave processing on the transverse strength, impact strength, surface hardness and the porosity of high-impact strength acrylic denture base material. High Impact Acryl was the heat-cured acrylic denture base material included in the study. A total of 120 specimens were prepared, the specimens were grouped into: control groups in which high-impact strength acrylic resins processed by conventional water-bath processing technique (74°C for 1.5 h then boil for 30 min) and experimental groups in which high-impact strength acrylic resins processed by autoclave at 121°C, 210 kPa .The experimental groups were divided into (fast) groups for 15 min, and (slow) groups for 30 min. To study the effect of the autoclave processing (Tuttnauer 2540EA), four tests were conducted transverse strength (Instron universal testing machine), impact strength (Charpy tester), surface hardness (shore D), and porosity test. The results were analyzed to ANOVA and LSD test. In ANOVA test, there were highly significant differences between the results of the processing techniques in transverse, impact, hardness, and porosity test. The LSD test showed a significant difference between control and fast groups in transverse and hardness tests and a non-significant difference in impact test and a highly significant difference in porosity test; while, there were a highly significant differences between control and slow groups in all examined tests; finally, there were a non-significant difference between fast and slow groups in transverse and porosity tests and a highly significant difference in impact and hardness tests. In the autoclave processing technique, the slow (long) curing cycle improved the tested physical and mechanical properties as compared with the fast (short) curing cycle. The autoclave processing technique improved the tested physical and mechanical properties of High Impact Acryl. Copyright © 2013 Japan Prosthodontic Society

Bilateral Acute Angle-closure after Intraocular Surgery.

Science.gov (United States)

Hoskens, Kirsten; Pinto, Luis Abegão; Vandewalle, Evelien; Verdonk, Nancy; Stalmans, Ingeborg

2014-01-01

We report the case of a 75-year-old woman who developed an acute bilateral angle-closure associated with choroidal effusion a day after an uneventful cataract surgery. The same patient had undergone a similarly uneventful cataract surgery two weeks before, under the same protocol, with no postoperative complication in the other eye. Medical treatment, including the use of oral sulfamide-related drugs (acetazolamide), topical beta-blockers and steroids led to a gradual decrease in intraocular pressure (IOP) and choroidal effusion. Despite initial reports suggesting a link between sulfamide-exposure and these rare forms of angle-closure, our report would suggest a more complex pathophysiology behind this intriguing phenomenon. How to cite this article: Hoskens K, Pinto LA, Vandewalle E, Verdonk N, Stalmans I. Bilateral Acute Angle-closure after Intraocular Surgery. J Curr Glaucoma Pract 2014;8(3):113-114.

40 CFR 180.1162 - Acrylate polymers and copolymers; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Acrylate polymers and copolymers... RESIDUES IN FOOD Exemptions From Tolerances § 180.1162 Acrylate polymers and copolymers; exemption from the requirement of a tolerance. (a) Acrylate polymers and copolymers are exempt from the requirement of a...

Transparent Hydrophobic Coating by Sol Gel Method

International Nuclear Information System (INIS)

Mohd Hamzah Harun; Nik Ghazali Nik Salleh; Mahathir Mohamed; Mohd Sofian Alias

2016-01-01

Transparent hydrophobic coating of inorganic based tetra orthosilicate (TEOS) was prepared by sol gel method by varying fluoroalkylsilane (FAS) content which works as hydrophobic agent. Surface contact angle, transmittance degree and surface morphology were characterized for each sample. All samples show good transparency which was confirmed by UV visible spectroscopy. The hydrophobicity obtained increases with FAS content indicates that FAS is best candidate to induce hydrophobicity for inorganic coating. (author)

Effect of wall wettability on flow characteristics of gas-liquid two-phase flow

International Nuclear Information System (INIS)

Uematsu, Junichi; Abe, Kazuya; Hazuku, Tatsuya; Takamasa, Tomoji; Hibiki, Takashi

2007-01-01

To evaluate the effect of surface wettability in pipe wall on flow characteristics in a vertical upward gas-liquid to-phase flow, visualization study was performed using three test pipes, namely an acrylic pipe, a hydrophilic pipe, a hydrophobic pipe. Such basic flow characteristics as flow patterns and void fraction were investigated in these three pipes. In the hydrophilic pipe, the slug flow-to-churn flow transition boundary was shifted to higher gas velocity condition at a given liquid velocity, whereas the churn flow-to-annular flow transition boundary was shifted to lower gas velocity condition at a given liquid velocity. In the hydrophobic pipe, the inverted-churn flow regime was observed in the region where the churn flow regime was observed in the acrylic pipe, whereas the droplet flow regime was observed in the region where the annular flow regime was observed in the acrylic pipe. At high-gas flow rate condition, the mean void fraction in the hydrophobic pipe took relatively higher value to that in the acrylic pipe. (author)

Changes of intraocular pressure in different trimesters of pregnancy among Syrian refugees in Turkey: A cross-sectional study.

Science.gov (United States)

Tolunay, Harun Egemen; Özcan, Sait Coşkun; Şükür, Yavuz Emre; Özarslan Özcan, Deniz; Adıbelli, Fatih Mehmet; Hilali, Neşe Gül

2016-06-01

To evaluate the physiologic changes in intraocular pressure associated with pregnancy in healthy Syrian refugee women in Turkey. In this cross-sectional study, intraocular pressures were measured using a Goldmann tonometer in 235 patients in the first, second, and third trimester of pregnancy and puerperium among Syrian refugees in Turkey. Mean intraocular pressures values of the right eye were 15.5±2.5 mmHg, 14.4±1.4 mmHg, 13.9±1.6 and 14.7±1.9 mmHg in the three trimesters and puerperium, respectively. Mean intraocular pressures values of the left eye were 15.3±1.6 mmHg, 14.3±1.4 mmHg, 13.9±1.6 and 15.3±2.2 mmHg in the three trimesters and puerperium, respectively. The mean intraocular pressures values measured from both eyes were significantly higher in first trimester and puerperal period than in the third trimester (p<0.001). Changes in the intraocular pressure in pregnancy are common and temporary. This study shows the baseline changes in the intraocular pressure during pregnancy in healthy women. Therefore, we cannot extrapolate the results to the whole eye. A decrease in intraocular pressures was shown in healthy pregnant women.

INTRAOCULAR TRANSMISSIBLE VENEREAL TUMOR IN A DOG TUMOR VENÉREO TRANSMISSÍVEL INTRA-OCULAR EM CÃO

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Geórgia Nadalini Rodrigues

2001-02-01

Full Text Available Canine transmissible venereal tumor (TVT is a round cell neoplasm occurring on the external genital mucosa of male and female dogs. Transmission is by cell implantation during coitus, licking, or other interaction between an affected dog and a susceptible host. Metastasis of the tumor rarely occurs. This report describes an unusual presentation of TVT with intraocular involvement and inguinal lymph nodes metastasis. The subject was a six-year-old, intact, male, Brazilian Terrier dog with a history of abnormal masses in the right eye, penis and several subcutaneous nodules in the inguinal area. Histopathological examination of the eye specimens as well as cytologic examination of penile mass and subcutaneous nodules revealed similar findings. The examination revealed round cells containing a large nuclei with prominent, central located nucleoli and a pale cytoplasm containing few small, clear round vacuoles. Histologically, the subcutaneous nodules in the inguinal area were lymph nodes. The diagnosis of TVT with intraocular involvement and lymph nodes metastasis was based on clinical, cytologic and histopathologic findings.Tumor venéreo transmissível (TVT é uma neoplasia de células redondas que acomete a mucosa genital externa de cães, machos e fêmeas. A transmissão decorre da implantação de células tumorais durante o coito, brigas ou interações entre animais portadores e susceptíveis. Existem relatos referindo-se a localizações atípicas do TVT, mas metástases raramente ocorrem. O presente relato descreve um caso incomum de TVT, com acometimento intra-ocular e metástases nos linfonodos ingüinais, num cão Terrier Brasileiro, com seis anos de idade. O animal apresentava massas anormais de tecido no olho direito, extremidade do pênis e aumento de volume de linfonodos da região ingüinal. A histopatologia do globo ocular e as citologias da massa peniana e dos nódulos subcutâneos evidenciaram aspectos citológicos semelhantes

Shape Memory Polymers Containing Higher Acrylate Content Display Increased Endothelial Cell Attachment

Science.gov (United States)

Govindarajan, Tina; Shandas, Robin

2018-01-01

Shape Memory Polymers (SMPs) are smart materials that can recall their shape upon the application of a stimulus, which makes them appealing materials for a variety of applications, especially in biomedical devices. Most prior SMP research has focused on tuning bulk properties; studying surface effects of SMPs may extend the use of these materials to blood-contacting applications, such as cardiovascular stents, where surfaces that support rapid endothelialization have been correlated to stent success. Here, we evaluate endothelial attachment onto the surfaces of a family of SMPs previously developed in our group that have shown promise for biomedical devices. Nine SMP formulations containing varying amounts of tert-Butyl acrylate (tBA) and Poly(ethylene glycol) dimethacrylate (PEGDMA) were analyzed for endothelial cell attachment. Dynamic mechanical analysis (DMA), contact angle studies, and atomic force microscopy (AFM) were used to verify bulk and surface properties of the SMPs. Human umbilical vein endothelial cell (HUVEC) attachment and viability was verified using fluorescent methods. Endothelial cells preferentially attached to SMPs with higher tBA content, which have rougher, more hydrophobic surfaces. HUVECs also displayed an increased metabolic activity on these high tBA SMPs over the course of the study. This class of SMPs may be promising candidates for next generation blood-contacting devices. PMID:29707382

Shape Memory Polymers Containing Higher Acrylate Content Display Increased Endothelial Cell Attachment

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Tina Govindarajan

2017-11-01

Full Text Available Shape Memory Polymers (SMPs are smart materials that can recall their shape upon the application of a stimulus, which makes them appealing materials for a variety of applications, especially in biomedical devices. Most prior SMP research has focused on tuning bulk properties; studying surface effects of SMPs may extend the use of these materials to blood-contacting applications, such as cardiovascular stents, where surfaces that support rapid endothelialization have been correlated to stent success. Here, we evaluate endothelial attachment onto the surfaces of a family of SMPs previously developed in our group that have shown promise for biomedical devices. Nine SMP formulations containing varying amounts of tert-Butyl acrylate (tBA and Poly(ethylene glycol dimethacrylate (PEGDMA were analyzed for endothelial cell attachment. Dynamic mechanical analysis (DMA, contact angle studies, and atomic force microscopy (AFM were used to verify bulk and surface properties of the SMPs. Human umbilical vein endothelial cell (HUVEC attachment and viability was verified using fluorescent methods. Endothelial cells preferentially attached to SMPs with higher tBA content, which have rougher, more hydrophobic surfaces. HUVECs also displayed an increased metabolic activity on these high tBA SMPs over the course of the study. This class of SMPs may be promising candidates for next generation blood-contacting devices.

Cytotoxicity Evaluation of Two Bis-Acryl Composite Resins Using Human Gingival Fibroblasts.

Science.gov (United States)

Gonçalves, Fabiano Palmeira; Alves, Gutemberg; Guimarães, Vladi Oliveira; Gallito, Marco Antônio; Oliveira, Felipe; Scelza, Míriam Zaccaro

2016-01-01

Bis-acryl resins are used for temporary dental restorations and have shown advantages over other materials. The aim of this work was to evaluate the in vitro cytotoxicity of two bis-acryl composite resins (Protemp 4 and Luxatemp Star), obtained at 1, 7 and 40 days after mixing the resin components, using a standardized assay employing human primary cells closely related to oral tissues. Human gingival fibroblast cell cultures were exposed for 24 h to either bis-acryl composite resins, polystyrene beads (negative control) and latex (positive control) extracts obtained after incubation by the different periods, at 37 °C under 5% CO2. Cell viability was evaluated using a multiparametric procedure involving sequential assessment (using the same cells) of mitochondrial activity (XTT assay), membrane integrity (neutral red test) and total cell density (crystal violet dye exclusion test). The cells exposed to the resin extracts showed cell viability indexes exceeding 75% after 24 h. Even when cells were exposed to extracts prepared with longer conditioning times, the bis-acryl composite resins showed no significant cytotoxic effects (p>0.05), compared to the control group or in relation to the first 24 h of contact with the products. There were no differences among the results obtained for the bis-acryl composite resins evaluated 24 h, 7 days and 40 days after mixing. It may be concluded that the bis-acryl resins Protemp 4 and Luxatemp Star were cytocompatible with human gingival fibroblasts, suggesting that both materials are suitable for use in contact with human tissues.

Structural degradation of acrylic bone cements due to in vivo and simulated aging.

Science.gov (United States)

Hughes, Kerry F; Ries, Michael D; Pruitt, Lisa A

2003-05-01

Acrylic bone cement is the primary load-bearing material used for the attachment of orthopedic devices to adjoining bone. Degradation of acrylic-based cements in vivo results in a loss of structural integrity of the bone-cement-prosthesis interface and limits the longevity of cemented orthopedic implants. The purpose of this study is to investigate the effect of in vivo aging on the structure of the acrylic bone cement and to develop an in vitro artificial aging protocol that mimics the observed degradation. Three sets of retrievals are examined in this study: Palacos brand cement retrieved from hip replacements, and Simplex brand cement retrieved from both hip and knee replacement surgeries. In vitro aging is performed using oxidative and acidic environments on three acrylic-based cements: Palacos, Simplex, and CORE. Gel permeation chromatography (GPC) and Fourier transform infrared spectroscopy (FTIR) are used to examine the evolution of molecular weight and chemical species within the acrylic cements due to both in vivo and simulated aging. GPC analysis indicates that molecular weight is degraded in the hip retrievals but not in the knee retrievals. Artificial aging in an oxidative environment best reproduces this degradation mechanism. FTIR analysis indicates that there exists a chemical evolution within the cement due to in vivo and in vitro aging. These findings are consistent with scission-based degradation schemes in the cement. Based on the results of this study, a pathway for structural degradation of acrylic bone cement is proposed. The findings from this investigation have broad applicability to acrylic-based cements and may provide guidance for the development of new bone cements that resist degradation in the body. Copyright 2003 Wiley Periodicals, Inc.

An ORMOSIL-Containing Orthodontic Acrylic Resin with Concomitant Improvements in Antimicrobial and Fracture Toughness Properties

Science.gov (United States)

Rueggeberg, Frederick A.; Niu, Li-na; Mettenberg, Donald; Yiu, Cynthia K. Y.; Blizzard, John D.; Wu, Christine D.; Mao, Jing; Drisko, Connie L.; Pashley, David H.; Tay, Franklin R.

2012-01-01

Global increase in patients seeking orthodontic treatment creates a demand for the use of acrylic resins in removable appliances and retainers. Orthodontic removable appliance wearers have a higher risk of oral infections that are caused by the formation of bacterial and fungal biofilms on the appliance surface. Here, we present the synthetic route for an antibacterial and antifungal organically-modified silicate (ORMOSIL) that has multiple methacryloloxy functionalities attached to a siloxane backbone (quaternary ammonium methacryloxy silicate, or QAMS). By dissolving the water-insoluble, rubbery ORMOSIL in methyl methacrylate, QAMS may be copolymerized with polymethyl methacrylate, and covalently incorporated in the pressure-processed acrylic resin. The latter demonstrated a predominantly contact-killing effect on Streptococcus mutans ATCC 36558 and Actinomyces naselundii ATCC 12104 biofilms, while inhibiting adhesion of Candida albicans ATCC 90028 on the acrylic surface. Apart from its favorable antimicrobial activities, QAMS-containing acrylic resins exhibited decreased water wettability and improved toughness, without adversely affecting the flexural strength and modulus, water sorption and solubility, when compared with QAMS-free acrylic resin. The covalently bound, antimicrobial orthodontic acrylic resin with improved toughness represents advancement over other experimental antimicrobial acrylic resin formulations, in its potential to simultaneously prevent oral infections during appliance wear, and improve the fracture resistance of those appliances. PMID:22870322

The transverse strength of acrylic resin after Coleus amboinicus, Lour extract solution immersion

OpenAIRE

Rianti, Devi

2006-01-01

A laboratoric experimental study was conducted on the transverse strength of acrylic resin after Coleus amboinicus, Lour extract solution immersion. The aim of this study is to know the difference of acrylic resin transverse strengths caused by immersion time variations in a concentrate solution. The study was carried out on unpolished acrylic resin plates with 65 × 10 × 2,5 mm dimension; solution with 15% Coleus amboinicus, Lour extract, and 30, 60, 90 days immersion times to measure the tra...

[Hormonal homeostasis and intraocular pressure in chronic emotional stress caused by influences acting on the amygdala].

Science.gov (United States)

Isakova, L S; Danilov, G E; Egorkina, S B; Butolin, E G

1989-01-01

Changes in intraocular pressure, eye hydrodynamics and the amount of hypophyseal, thyroid, adrenal and pancreatic hormones were studied during continuous stimulation of amygdaloid complex or after administration of angiotensin II into the structure in rabbits. The effects involved changes in hormonal homeostasis and elevation of intraocular pressure due to a hypersecretion of intraocular fluid. The administration of angiotensin II during the amygdala stimulation enhanced the changes.

Intraocular lens fabrication

Energy Technology Data Exchange (ETDEWEB)

Salazar, M.A.; Foreman, L.R.

1997-07-08

This invention describes a method for fabricating an intraocular lens made from clear Teflon{trademark}, Mylar{trademark}, or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube. 13 figs.

Ultraviolet curing of acrylated liquid natural rubber for surface coating application

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Kannikar Kwanming

2009-01-01

Full Text Available Ultraviolet curable acrylated liquid natural rubber was prepared by grafting of photosensitive molecule onto liquid natural rubber for surface coating application. The liquid natural rubber (LNR was firstly obtained by degradation of natural rubber latex with hydrogen peroxide and cobalt acetylacetonate at 65oC for 72 hrs. The preparation of acrylated natural rubber was carried out by the reaction of acrylic acid and epoxidized liquid natural rubber (ELNR prior obtained from LNR with formic acid and hydrogen peroxide in the ratio of 2:1 by weight in toluene at 80oC for 6, 9, 12, 18, and 24 hrs. It was found that the percentage of acrylate grafted onto liquid natural rubber depended on the reaction time. Surface coating was performed by using acrylated liquid natural rubber and 1,6-hexanediol diacrylate (HDDA or tripropylene glycol diacrylate (TPGDA as a crosslinker and Irgarcure 184 or Irgarcure 651 as a photoinitiator under UV exposure for 30, 60, and 90 seconds. The hardness test of cured products was investigated using the Pencil hardness test at pencil level of 2B to 6H. It was found that the highest hardness of surface coating was at pencil level of 4H for the product using TPGDA and Irgacure 651 in the ratio of 80:10 parts per hundred of rubber (phr. The cured products were able to resist to 2% H2SO4 and distilled water for more than 24 hrs.

MRI and intraocular tamponade media

Energy Technology Data Exchange (ETDEWEB)

Manfre, I. (Dept. of Neuroradiology, Inst. of Neurosurgery, Univ. of Catania (Italy)); Fabbri, G. (Dept. of Neuroradiology, Inst. of Neurosurgery, Univ. of Catania (Italy)); Avitabile, T. (Inst. of Ophthalmology, Univ. of Catania (Italy)); Biondi, P. (Inst. of Ophthalmology, Univ. of Catania (Italy)); Reibaldi, A. (Inst. of Ophthalmology, Univ. of Catania (Italy)); Pero, G. (Dept. of Neuroradiology, Inst. of Neurosurgery, Univ. of Catania (Italy))

1993-05-01

Thirteen patients who underwent surgery for retinal detachment and injection of intraocular tamponade media (silicone oil, flurosilicone oil, or perfluoro-carbon liquid) underwent magnetic resonance imaging (MRI), using spin-echo T1- and T2-weighted images. The ophthalmic tamponade media showed different signal intensity, according to their chemical structure. Unlike ophthalmoscopy or ultrasonography, MRI showed no oil-related artefact, making possible recognition of recurrent retinal detachment. (orig.)

MRI and intraocular tamponade media

International Nuclear Information System (INIS)

Manfre, I.; Fabbri, G.; Avitabile, T.; Biondi, P.; Reibaldi, A.; Pero, G.

1993-01-01

Thirteen patients who underwent surgery for retinal detachment and injection of intraocular tamponade media (silicone oil, flurosilicone oil, or perfluoro-carbon liquid) underwent magnetic resonance imaging (MRI), using spin-echo T1- and T2-weighted images. The ophthalmic tamponade media showed different signal intensity, according to their chemical structure. Unlike ophthalmoscopy or ultrasonography, MRI showed no oil-related artefact, making possible recognition of recurrent retinal detachment. (orig.)

Liposomes coated with hydrophobically modified hydroxyethyl cellulose: Influence of hydrophobic chain length and degree of modification.

Science.gov (United States)

Smistad, Gro; Nyström, Bo; Zhu, Kaizheng; Grønvold, Marthe Karoline; Røv-Johnsen, Anne; Hiorth, Marianne

2017-08-01

Nanoparticulate systems with an uncharged hydrophilic surface may have a great potential in mucosal drug delivery. In the present study liposomes were coated with hydrophobically modified hydroxyethyl cellulose (HM-HEC) to create a sterically stabilized liposomal system with an uncharged surface. The aim was to clarify the influence of the amount of hydrophobic modification of HEC and the length of the hydrophobic moiety, on the stability of the system and on the release properties. HM-HEC with different degrees of hydrophobic modification (1 and 2mol%) and hydrophobic groups with different chain lengths (C8, C12, C16) were included in the study, as well as fluid phase and gel phase liposomes. Both types of liposomes were successfully coated with HM-HEC containing 1mol% of hydrophobic groups, while 2mol% did not work for the intended pharmaceutical applications. The polymer coated gel phase liposomes were stable (size, zeta potential, leakage) for 24 weeks at 4°C, with no differences between the C8 and C16 HM-HEC coating. For the fluid phase liposomes a size increase was observed after 24 weeks at 4°C for all formulations; the C8 HM-HEC coated liposomes increased the most. No differences in the leakage during storage at 4°C or in the release at 35°C were observed between the fluid phase formulations. To conclude; HM-HEC with a shorter hydrophobic chain length resulted in a less stable product for the fluid phase liposomes, while no influence of the chain length was observed for the gel phase liposomes (1mol% HM). Copyright © 2017 Elsevier B.V. All rights reserved.

Adsorption of hydrophobic organic compounds onto a hydrophobic carbonaceous geosorbent in the presence of surfactants.

Science.gov (United States)

Wang, Peng; Keller, Arturo A

2008-06-01

The adsorption of hydrophobic organic compounds (HOCs; atrazine and diuron) onto lampblack was studied in the presence of nonionic, cationic, and anionic surfactants (Triton(R) X-100), benzalkonium chloride [BC], and linear alkylbenzene sulfonate [LAS]) to determine the effect of the surfactant on HOC adsorption onto a hydrophobic carbonaceous geosorbent. Linear alkylbenzene sulfonate showed an adsorption capacity higher than that of BC but similar to that of Triton X-100, implying the charge property of a surfactant is not a useful indicator for predicting the surfactant's adsorption onto a hydrophobic medium. The results also indicated that the octanol-water partition coefficient (K(OW)) of a surfactant is not a good predictor of that surfactant's sorption onto a hydrophobic medium. Under subsaturation adsorption conditions (i.e., before sorption saturation is reached), surfactant adsorption reduced HOC adsorption to a significant extent, with the reduction in HOC adsorption increasing monotonically with the amount of surfactant adsorbed. Among the three surfactants, Triton X-100 was the most effective in reducing HOC adsorption, whereas BC and LAS showed similar effectiveness in this regard. Under the same amount of the surfactant sorbed, the reduction in atrazine adsorption was consistently greater than that for diuron because of atrazine's lower hydrophobicity. No significant difference was observed in the amount of the HOC adsorbed under different adsorption sequences. Our results showed that the presence of surfactant can significantly decrease HOC adsorption onto hydrophobic environmental media and, thus, is important in predicting HOC fate and transport in the environment.

Central Corneal Thickness And Its Relationship To Intra-ocular And Epidemiological Determinants

International Nuclear Information System (INIS)

Tayyab, A.; Masrur, A.

2016-01-01

Objective: To measure central corneal thickness in Pakistani population and determine its relationship to intra-ocular pressure, age, gender and ethnicity. Study Design: Cross-sectional observation study. Place and Duration of Study: Pakistan Institute of Medical Sciences, Islamabad, Pakistan, between December 2013 and February 2015. Methodology: The right eyes of 1000 cases (496 males and 504 females) were recruited for this study. Inclusion criteria were Pashtun or Punjabi ethnicity, intra-ocular pressure < 22 mmHg, gonioscopically open angles, cup-disk-ratio < 0.5, and age matched normal visual fields. Cases with prior ocular surgery, contact lens use, corneal pathologies, myopia or hypermetropia > ±3.0 diopters, astigmatism of > ±1.0 diopters were excluded. Central corneal thickness was measured using a TopCon non-contact specular microscope. Intra-ocular pressure was measured using Goldmann applanation tonometer. Frequency distribution, test of significance, and regression analysis was carried out using Statistical Package for Social Sciences version 20.0. Result: Mean age was 47.31 ±11.78 years. Ethnic composition was 51.6 percentage (n=516) Pashtun and 48.4 percentage (n=484) Punjabi. The mean central corneal thickness was 503.96 (±12.47) meu m, while the mean intra-ocular pressure was 15.61 (±2.68) mmHg. Regression analysis showed a significant association between central corneal thickness and intra-ocular pressure (p=0.00) and age (p=0.00). A ±100 μ change in central corneal thickness was associated with change in IOP of ±3.30 mmHg, whereas central corneal thickness decreased by 0.12 meu m per year. No significant association could be established between central corneal thickness and ethnicity (p=0.19). Conclusion: Central corneal thickness of the studied races was comparable to non-Caucasians which affects intra-ocular pressure measurements, and decreases with increasing age. No relationship was observed between central corneal thickness and

Comparison of Bigbag and Rayner620H intraocular lens in cataract surgeries in high myopia patients

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Zhan-Jiang Liu

2016-01-01

Full Text Available AIM:To investigate the effects of Bigbag and Rayner620H intraocular lens in cataract surgeries in high myopia patients. METHODS:Seventy-seven patients(128 eyeswere treated by phacoemulsification combined with intraocular lens implantation from January 2014 to March 2015 in our hospital. Thirty-nine patients(65 eyeswere treated with Bigbag intraocular lens, 38 cases(63 eyeswere treated with Rayner620H. The best corrected visual acuity(BCVAdistribution, the actual refractive value, the difference between predictive refractive value and actual refractive value and complications were measured and recorded in the two groups at 1mo after surgeries. RESULTS:The difference between the two groups on BCVA are statistically significant(PWilcoxon rank sum test. The differences between predictive refractive value and actual refractive value of the two groups were statistically significant(PPCONCLUSION:The effect of Bigbag intraocular lens for patients with phacoemulsification and intraocular lens implantation is good, and it can reduce the risk of complications.

Super-hydrophobic surfaces of SiO₂-coated SiC nanowires: fabrication, mechanism and ultraviolet-durable super-hydrophobicity.

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Zhao, Jian; Li, Zhenjiang; Zhang, Meng; Meng, Alan

2015-04-15

The interest in highly water-repellent surfaces of SiO2-coated SiC nanowires has grown in recent years due to the desire for self-cleaning and anticorrosive surfaces. It is imperative that a simple chemical treatment with fluoroalkylsilane (FAS, CF3(CF2)7CH2CH2Si(OC2H5)3) in ethanol solution at room temperature resulted in super-hydrophobic surfaces of SiO2-coated SiC nanowires. The static water contact angle of SiO2-coated SiC nanowires surfaces was changed from 0° to 153° and the morphology, microstructure and crystal phase of the products were almost no transformation before and after super-hydrophobic treatment. Moreover, a mechanism was expounded reasonably, which could elucidate the reasons for their super-hydrophobic behavior. It is important that the super-hydrophobic surfaces of SiO2-coated SiC nanowires possessed ultraviolet-durable (UV-durable) super-hydrophobicity. Copyright © 2014 Elsevier Inc. All rights reserved.

Study of protein-probe complexation equilibria and protein-surfactant interaction using charge transfer fluorescence probe methyl ester of N,N-dimethylamino naphthyl acrylic acid

Energy Technology Data Exchange (ETDEWEB)

Mahanta, Subrata; Balia Singh, Rupashree; Bagchi, Arnab [Department of Chemistry University of Calcutta 92, A.P.C. Road, Kolkata 700009 (India); Nath, Debnarayan [Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Guchhait, Nikhil, E-mail: nguchhait@yahoo.co [Department of Chemistry University of Calcutta 92, A.P.C. Road, Kolkata 700009 (India)

2010-06-15

In this paper, we demonstrate the interaction between intramolecular charge transfer (ICT) probe-Methyl ester of N,N-dimethylamino naphthyl acrylic acid (MDMANA) with bovine serum albumin (BSA) using absorption and fluorescence emission spectroscopy. The nature of probe protein binding interaction, fluorescence resonance energy transfer from protein to probe and time resolved fluorescence decay measurement predict that the probe molecule binds strongly to the hydrophobic cavity of the protein. Furthermore, the interaction of the anionic surfactant sodium dodecyl sulphate (SDS) with water soluble protein BSA has been investigated using MDMANA as fluorescenece probe. The changes in the spectral characteristics of charge transfer fluorescence probe MDMANA in BSA-SDS environment reflects well the nature of the protein-surfactant binding interaction such as specific binding, non-cooperative binding, cooperative binding and saturation binding.

Determining color difference thresholds in denture base acrylic resin.

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Ren, Jiabao; Lin, Hong; Huang, Qingmei; Zheng, Gang

2015-11-01

In restorative prostheses, color is important, but the choice of color difference formula used to quantify color change in acrylic resins is not straightforward. The purpose of this in vitro study was to choose a color difference formula that best represented differences between the calculated color and the observed imperceptible to unacceptable color and to determine the corresponding perceptibility and acceptability threshold of color stability for denture base acrylic resins. A total of 291 acrylic resin denture base plates were fabricated and subjected to radiation tests from zero to 42 hours in accordance with ISO 7491:2000. Color was measured with a portable spectrophotometer, and color differences were calculated with 3 International Commission on Illumination (CIE) formulas: CIELab, CMC(1:1), and CIEDE2000. Thirty-four observers with no deficiencies in color perception participated in psychophysical perceptibility and acceptability assessments under controlled conditions in vitro. These 2 types of assessments were regressed to each observer by each formula to generate receiver operator characteristic (ROC) curves. Areas under the curves (AUCs) were then calculated and analyzed to exclude observers with poor color discrimination. AUCs were subjected to 1-way ANOVA (α=.05) to deter the statistical significance of discriminability among the 3 formulas in terms of perceptibility and acceptability judgments. Student-Newman-Keuls tests (α=.05) were used for post hoc comparison. CMC(1:1) and CIEDE2000 formulas performed better for imperceptible to unacceptable color differences, with corresponding CMC(1:1) and CIEDE2000 values for perceptibility of 2.52 and 1.72, respectively, and acceptability thresholds of 6.21 and 4.08, respectively. Formulas CMC(1:1) and CIEDE2000 possess higher discriminability than that of CIELab in the assessment of perceptible color difference threshold of denture base acrylic resin. A statistically significant difference exists

Investigation of UV curing reaction of dicyclopentadienyl acrylate by FT-IR

International Nuclear Information System (INIS)

Lu Qiting; Hou Yibin

1999-01-01

Dicyclopentadienyl acrylate (DCPA) is characterized by low odor, low volatility, high flash point, low toxicity and low shrinkage on cure. Another advantage of DCPA is its insensitiveness to the inhibiting effect of oxygen. DCPA have wide industrial applications. It was used for the preparation of adhesives, UV-curable coatings and polymer concreted). The advantages of DCPA result from its particular structure. There are two unsaturated bonds, one acrylic double bond and one cyclic double bond, in each DCPA molecule. But, few reports on reaction behavior of the two type double bonds were issued up to date. In this paper, reaction behavior of the acrylic and the cyclic double bond of DCPA during and after LTV-curing were investigated by Fourier Transform-Infrared(FT-IR)

Characterisation of nanomaterial hydrophobicity using engineered surfaces

Energy Technology Data Exchange (ETDEWEB)

Desmet, Cloé; Valsesia, Andrea; Oddo, Arianna; Ceccone, Giacomo; Spampinato, Valentina; Rossi, François; Colpo, Pascal, E-mail: pascal.colpo@ec.europa.eu [Directorate Health, Consumer and Reference Materials, Consumer Products Safety Unit (Italy)

2017-03-15

Characterisation of engineered nanomaterials (NMs) is of outmost importance for the assessment of the potential risks arising from their extensive use. NMs display indeed a large variety of physico-chemical properties that drastically affect their interaction with biological systems. Among them, hydrophobicity is an important property that is nevertheless only slightly covered by the current physico-chemical characterisation techniques. In this work, we developed a method for the direct characterisation of NM hydrophobicity. The determination of the nanomaterial hydrophobic character is carried out by the direct measurement of the affinity of the NMs for different collectors. Each collector is an engineered surface designed in order to present specific surface charge and hydrophobicity degrees. Being thus characterised by a combination of surface energy components, the collectors enable the NM immobilisation with surface coverage in relation to their hydrophobicity. The experimental results are explained by using the extended DLVO theory, which takes into account the hydrophobic forces acting between NMs and collectors.

Evaluating the risk of eye injuries: intraocular pressure during high speed projectile impacts.

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Duma, Stefan M; Bisplinghoff, Jill A; Senge, Danielle M; McNally, Craig; Alphonse, Vanessa D

2012-01-01

To evaluate the risk of eye injuries by determining intraocular pressure during high speed projectile impacts. A pneumatic cannon was used to impact eyes with a variety of projectiles at multiple velocities. Intraocular pressure was measured with a small pressure sensor inserted through the optic nerve. A total of 36 tests were performed on 12 porcine eyes with a range of velocities between 6.2 m/s and 66.5 m/s. Projectiles selected for the test series included a 6.35  mm diameter metal ball, a 9.25  mm diameter aluminum rod, and an 11.16  mm diameter aluminum rod. Experiments were designed with velocities in the range of projectile consumer products such as toy guns. A range of intraocular pressures ranged between 2017 mmHg to 26,426 mmHg (39 psi-511 psi). Four of the 36 impacts resulted in globe rupture. Intraocular pressures dramatically above normal physiological pressure were observed for high speed projectile impacts. These pressure data provide critical insight to chronic ocular injuries and long-term complications such as glaucoma and cataracts.

Modelling oral up-take of hydrophobic and super-hydrophobic chemicals in fish.

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Larisch, Wolfgang; Goss, Kai-Uwe

2018-01-24

We have extended a recently published toxicokinetic model for fish (TK-fish) towards the oral up-take of contaminants. Validation with hydrophobic chemicals revealed that diffusive transport through aqueous boundary layers in the gastro-intestinal tract and in the blood is the limiting process. This process can only be modelled correctly if facilitated transport by albumin or bile micelles through these boundary layers is accounted for. In a case study we have investigated the up-take of a super hydrophobic chemical, Dechlorane Plus. Our results suggest that there is no indication of a hydrophobicity or size cut-off in the bioconcentration of this chemical. Based on an extremely high, but mechanistically sound facilitation factor we received model results in good agreement with experimental values from the literature. The results also indicate that established experimental procedures for BCF determination cannot cover the very slow up-take and clearance kinetics that are to be expected for such a chemical.

Dynamics of Wetting of Ultra Hydrophobic Surfaces

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Mohammad Karim, Alireza; Kim, Jeong-Hyun; Rothstein, Jonathan; Kavehpour, Pirouz; Mechanical and Industrial Engineering, University of Massachusetts, Amherst Collaboration

2013-11-01

Controlling the surface wettability of hydrophobic and super hydrophobic surfaces has extensive industrial applications ranging from coating, painting and printing technology and waterproof clothing to efficiency increase in power and water plants. This requires enhancing the knowledge about the dynamics of wetting on these hydrophobic surfaces. We have done experimental investigation on the dynamics of wetting on hydrophobic surfaces by looking deeply in to the dependency of the dynamic contact angles both advancing and receding on the velocity of the three-phase boundary (Solid/Liquid/Gas interface) using the Wilhelmy plate method with different ultra-hydrophobic surfaces. Several fluids with different surface tension and viscosity are used to study the effect of physical properties of liquids on the governing laws.

Anionic polymerization of acrylates. XIV. Synthesis of MMA/acrylate block copolymers initiated with ester-enolate/tert-alkoxide complex

Czech Academy of Sciences Publication Activity Database

Vlček, Petr; Čadová, Eva; Kříž, Jaroslav; Látalová, Petra; Janata, Miroslav; Toman, Luděk; Masař, Bohumil

2005-01-01

Roč. 46, č. 14 (2005), s. 4991-5000 ISSN 0032-3861 Institutional research plan: CEZ:AV0Z4050913 Keywords : ligated anionic polymerization * (meth)acrylates * block copolymers Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.849, year: 2005

rac-tert-Butyl{2-hydroxy-2-[4-hydroxy-3-(hydroxymethylphenyl]ethyl}azanium acrylate

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Wenju Liu

2017-08-01

Full Text Available The title salt, C13H22NO3+·C3H3O2−, comprises one salbutamol cation and an acrylate anion. The acrylate anion is linked to the salbutamol cation via an O—H...O and an N—H...O hydrogen bond. The C=C group of the acrylate anion is disordered over two positions, with refined site occupancies of 0.812 (7 and 0.188 (7. The crystal structure is stabilized by N—H...O and O—H...O hydrogen-bonding interactions.

Stability of Adrenaline in Irrigating Solution for Intraocular Surgery.

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Shibata, Yuuka; Kimura, Yasuhiro; Taogoshi, Takanori; Matsuo, Hiroaki; Kihira, Kenji

2016-01-01

Intraocular irrigating solution containing 1 µg/mL adrenaline is widely used during cataract surgery to maintain pupil dilation. Prepared intraocular irrigating solutions are recommended for use within 6 h. After the irrigating solution is admistered for dilution, the adrenaline may become oxidized, and this may result in a decrease in its biological activity. However, the stability of adrenaline in intraocular irrigating solution is not fully understood. The aim of this study was to evaluate the stability of adrenaline in clinically used irrigating solutions of varying pH. Six hours after mixing, the adrenaline percentages remaining were 90.6%±3.7 (pH 7.2), 91.1%±2.2 (pH 7.5), and 65.2%±2.8 (pH 8.0) of the initial concentration. One hour after mixing, the percentages remaining were 97.6%±2.0 (pH 7.2), 97.4%±2.7 (pH 7.5), and 95.6%±3.3 (pH 8.0). The degradation was especially remarkable and time dependent in the solution at pH 8.0. These results indicate that the concentration of adrenaline is decreased after preparation. Moreover, we investigated the influence of sodium bisulfite on adrenaline stability in irrigating solution. The percentage adrenaline remaining at 6 h after mixing in irrigating solution (pH 8.0) containing sodium bisulfite at 0.5 µg/mL (concentration in irrigating solution) or at 500 µg/mL (concentration in the undiluted adrenaline preparation) were 57.5 and 97.3%, respectively. Therefore, the low concentration of sodium bisulfite in the irrigating solution may be a cause of the adrenaline loss. In conclusion, intraocular irrigation solution with adrenaline should be prepared just prior to its use in surgery.

Experimental research on intraocular aqueous flow by PIV method.

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Yang, Hongyu; Song, Hongfang; Mei, Xi; Li, Lin; Fu, Xineng; Zhang, Mindi; Liu, Zhicheng

2013-10-21

Aqueous humor flows regularly from posterior chamber to anterior chamber, and this flow much involves intraocular pressure, the eye tissue nutrition and metabolism. To visualize and measure the intraocular flow regular pattern of aqueous humor. Intraocular flow in the vitro eyeball is driven to simulate the physiological aqueous humor flow, and the flow field is measured by Particle Image Velocimetry(PIV). Fluorescent particle solution of a certain concentration was infused into the root of Posterior Chamber(PC) of vitro rabbit eye to simulate the generation of aqueous and was drained out at a certain hydrostatic pressure from the angle of Anterior Chamber(AC) to represent the drainage of aqueous. PIV method was used to record and calculate the flow on the midsagittal plane of the eyeball. Velocity vector distribution in AC has been obtained, and the distribution shows symmetry feature to some extent. Fluorescent particle solution first fills the PC as it is continuously infused, then surges into AC through the pupil, flows upwards toward the central cornea, reflecting and scattering, and eventually converges along the inner cornea surface towards the outflow points at the periphery of the eyeball. Velocity values around the pupillary margin are within the range of 0.008-0.012 m/s, which are close to theoretical values of 0.0133 m/s, under the driving rate of 100 μl/min. Flow field of aqueous humor can be measured by PIV method, which makes it possible to study the aqueous humor dynamics by experimental method. Our study provides a basis for experimental research on aqueous humor flow; further, it possibly helps to diagnose and treat eye diseases as shear force damage of ocular tissues and destructions on corneal endothelial cells from the point of intraocular flow field.

Retropupillary iris claw intraocular lens implantation in aphakia for dislocated intraocular lens

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Faria MY

2016-08-01

Full Text Available Mun Yueh Faria,1–3 Nuno Pinto Ferreira,1–3 Joana Medeiros Pinto,1–3 David Cordeiro Sousa,1–3 Ines Leal,1–3 Eliana Neto,1–3 Carlos Marques-Neves1–3 1Centro de Estudos da Visão, Universidade de Lisboa, 2Department of Ophthalmology, Hospital de Santa Maria, 3Faculty of Medicine, University of Lisbon, Lisbon, Portugal Background: Nowadays, dislocated intraocular lenses (IOLs and inadequate capsular support are becoming a challenge for every ophthalmic surgeon. Explantation of dislocated IOL and iris claw IOL (ICIOL are the techniques that have been used in our ophthalmic department. The aim of this study is to report our technique for retropupillar ICIOL.Methods: This study is a retrospective case series. A total of 105 eyes with dislocated IOL from the patients at the Department of Ophthalmology in Santa Maria Hospital, a tertiary reference hospital in Lisbon, Portugal, from January 2012 until January 2016, had been analyzed. Of these 105 eyes, 66 eyes had dislocated one-piece IOL and 39 eyes had dislocated three-piece IOL. The latter underwent iris suture of the same IOL and were excluded from this study. The remaining 66 eyes with dislocated one-piece IOL underwent pars plana vitrectomy, that is, explantation of dislocated IOL through corneal incision and an implantation of retropupillary ICIOL. Operative data and postoperative outcomes included best corrected visual acuity, IOL position, intraocular pressure, pigment dispersion, clinical signs of endothelial cell loss, and anterior chamber depth.Results: The mean follow-up was 23 months (range: 6–48 months. The mean preoperative best corrected visual acuity was 1.260±0.771 logMAR, and postoperative best corrected visual acuity was 0.352±0.400 logMAR units. Mean vision gain was 0.909 logMar units. The patients had the following complications: 1 retinal detachment was found in one patient, 2 corneal edema was found in three patients, 3 high intraocular pressure was observed in

Thermodynamic Interactions between Polystyrene and Long-Chain Poly(n-Alkyl Acrylates) Derived from Plant Oils.

Science.gov (United States)

Wang, Shu; Robertson, Megan L

2015-06-10

Vegetable oils and their fatty acids are promising sources for the derivation of polymers. Long-chain poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) are readily derived from fatty acids through conversion of the carboxylic acid end-group to an acrylate or methacrylate group. The resulting polymers contain long alkyl side-chains with around 10-22 carbon atoms. Regardless of the monomer source, the presence of alkyl side-chains in poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) provides a convenient mechanism for tuning their physical properties. The development of structured multicomponent materials, including block copolymers and blends, containing poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) requires knowledge of the thermodynamic interactions governing their self-assembly, typically described by the Flory-Huggins interaction parameter χ. We have investigated the χ parameter between polystyrene and long-chain poly(n-alkyl acrylate) homopolymers and copolymers: specifically we have included poly(stearyl acrylate), poly(lauryl acrylate), and their random copolymers. Lauryl and stearyl acrylate were chosen as model alkyl acrylates derived from vegetable oils and have alkyl side-chain lengths of 12 and 18 carbon atoms, respectively. Polystyrene is included in this study as a model petroleum-sourced polymer, which has wide applicability in commercially relevant multicomponent polymeric materials. Two independent methods were employed to measure the χ parameter: cloud point measurements on binary blends and characterization of the order-disorder transition of triblock copolymers, which were in relatively good agreement with one another. The χ parameter was found to be independent of the alkyl side-chain length (n) for large values of n (i.e., n > 10). This behavior is in stark contrast to the n-dependence of the χ parameter predicted from solubility parameter theory. Our study complements prior work investigating the interactions between

Intraocular robotic interventional surgical system (IRISS): Mechanical design, evaluation, and master-slave manipulation.

Science.gov (United States)

Wilson, Jason T; Gerber, Matthew J; Prince, Stephen W; Chen, Cheng-Wei; Schwartz, Steven D; Hubschman, Jean-Pierre; Tsao, Tsu-Chin

2018-02-01

Since the advent of robotic-assisted surgery, the value of using robotic systems to assist in surgical procedures has been repeatedly demonstrated. However, existing technologies are unable to perform complete, multi-step procedures from start to finish. Many intraocular surgical steps continue to be manually performed. An intraocular robotic interventional surgical system (IRISS) capable of performing various intraocular surgical procedures was designed, fabricated, and evaluated. Methods were developed to evaluate the performance of the remote centers of motion (RCMs) using a stereo-camera setup and to assess the accuracy and precision of positioning the tool tip using an optical coherence tomography (OCT) system. The IRISS can simultaneously manipulate multiple surgical instruments, change between mounted tools using an onboard tool-change mechanism, and visualize the otherwise invisible RCMs to facilitate alignment of the RCM to the surgical incision. The accuracy of positioning the tool tip was measured to be 0.205±0.003 mm. The IRISS was evaluated by trained surgeons in a remote surgical theatre using post-mortem pig eyes and shown to be effective in completing many key steps in a variety of intraocular surgical procedures as well as being capable of performing an entire cataract extraction from start to finish. The IRISS represents a necessary step towards fully automated intraocular surgery and demonstrated accurate and precise master-slave manipulation for cataract removal and-through visual feedback-retinal vein cannulation. Copyright © 2017 John Wiley & Sons, Ltd.

Effects of phacoemulsification combined with intraocular lens implantation on ocular surface

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Ming Li

2013-10-01

Full Text Available AIM: To explore the changes of ocular surface after phacoemulsification combined with intraocular lens implantation. METHODS: Totally 78 cases of 78 eyes with age-related cataract were collected from August 2011 to October 2012, and they underwent corneal incision phacoemulsification combined with intraocular lens implantation. The score of dry eye symptoms; tear breakup time(BUT; Schirmer Ⅰ test(SⅠtand corneal fluorescein staining were observed and recorded in 3 days before, 1 day, 1 week, 1 month, 3 and 6 months after surgery respectively. The results were analyzed statistically. RESULTS: All the subjects complained of dry eye within 1 week after surgery. Compared with 3 days before the surgery, the corneal fluorescein staining increased and the amount of tear secretion reduced statistically significant in 1 day, 1 week and 1 month(PPP>0.05, and lasted to 3 months later. CONCLUSION: Phacoemulsification combined with intraocular lens implantation has obvious effect on the ocular surface to some extent. Preventions and treatment should be taken clinically.

Towards understanding hydrophobic recovery of plasma treated polymers: Storing in high polarity liquids suppresses hydrophobic recovery

International Nuclear Information System (INIS)

Bormashenko, Edward; Chaniel, Gilad; Grynyov, Roman

2013-01-01

The phenomenon of hydrophobic recovery was studied for cold air plasma treated polyethylene films. Plasma-treated polymer films were immersed into liquids with very different polarities such as ethanol, acetone, carbon tetrachloride, benzene and carbon disulphide. Hydrophobic recovery was studied by measurement of contact angles. Immersion into high polarity liquids slows markedly the hydrophobic recovery. We relate this slowing to dipole–dipole interaction of polar groups of the polymer with those of the liquids. This kind of interaction becomes decisive when polar groups of polymer chains are at least partially spatially fixed.

The Visual Effects of Intraocular Colored Filters

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Billy R. Hammond

2012-01-01

Full Text Available Modern life is associated with a myriad of visual problems, most notably refractive conditions such as myopia. Human ingenuity has addressed such problems using strategies such as spectacle lenses or surgical correction. There are other visual problems, however, that have been present throughout our evolutionary history and are not as easily solved by simply correcting refractive error. These problems include issues like glare disability and discomfort arising from intraocular scatter, photostress with the associated transient loss in vision that arises from short intense light exposures, or the ability to see objects in the distance through a veil of atmospheric haze. One likely biological solution to these more long-standing problems has been the use of colored intraocular filters. Many species, especially diurnal, incorporate chromophores from numerous sources (e.g., often plant pigments called carotenoids into ocular tissues to improve visual performance outdoors. This review summarizes information on the utility of such filters focusing on chromatic filtering by humans.

Electron beam curing of acrylic oligomers

International Nuclear Information System (INIS)

Seto, J.; Arakawa, S.; Ishimoto, C.; Miyashita, M.; Nagai, T.; Noguchi, T.; Shibata, A.

1984-01-01

The electron-beam curing process of acrylic oligomers, with and without γ-Fe 2 O 3 pigment filler and blended linear polymer, was investigated in terms of molecular structure and reaction mechanism. The polymerized fraction of trimethylolpropane-triacrylate (TMPTA) oligomers increases with increasing total dose, and is independent of the dose rate. Since the reaction rate is linearly dependent on the dose rate, the reaction mechanism involves monomolecular termination. The reaction rate does not depend on the number of functional groups of the oligomer at low doses, but above 0.3 Mrad the rate is slower for oligomers of higher functionality. A gel is formed more readily upon curing of a polyfunctional than a monofunctional oligomer, especially at high conversion to polymer; the resulting loss of flexibility of the polymer chains slows the reaction. Decrease of the molecular weight per functional group results in lower conversion; this is also due to the loss of chain flexibility, which is indicated as well by a higher glass-transition temperature. Modification of the acrylate oligomers with urethane results in more effective cross-linking reactions because of the more rigid molecular chains. Addition of γ-Fe 2 O 3 pigment reduces the reaction rate very little, but has the effect of providing added structural integrity, as indicated by the decrease of solvent-extractable material and the improvement of anti-abrasion properties. However, the flexibility of the coating and its adhesion to a PET base film are diminished. To increase the flexibility, linear polyvinylchloride and/or polyurethane were added to the acrylic oligomers. Final conversion to polymer was nearly 100 percent, and a higher elastic modulus and better antiabrasion properties were realized

Evaluation of intraocular pressure according to corneal thickness before and after excimer laser corneal ablation for myopia.

Science.gov (United States)

Hamed-Azzam, Shirin; Briscoe, Daniel; Tomkins, Oren; Shehedeh-Mashor, Raneen; Garzozi, Hanna

2013-08-01

Intraocular pressure is affected by corneal thickness and biomechanics. Following ablative corneal refractive surgery, corneal structural changes occur. The purpose of the study is to determine the relationship between the mean central corneal thickness (CCT) and the change in intraocular pressure measurements following various corneal ablation techniques, using different measurement methods. Two hundred myopic eyes undergoing laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) were enrolled into a prospective, non-randomized study. Corneal parameters examined included full ocular examination, measurement of CCT, corneal topography, corneal curvature and ocular refractivity. Intraocular pressure measurements were obtained using three different instruments-non-contact tonometer, Goldmann applanation tonometer and TonoPen XL (TonoPen-Central and TonoPen-Peripheral). All measurements were performed pre-operatively and 4 months post-operatively. Post-operative intraocular pressure was significantly lower than pre-operative values, with all instruments (p value tonometer and non-contact tonometer (p value < 0.001, ANOVA). Intraocular pressure readings are significantly reduced following corneal ablation surgery. We determined in our myopic patient cohort that the TonoPen XL intraocular pressure measurement method is the least affected following PRK and LASIK as compared to other techniques.

Transdermal thiol-acrylate polyethylene glycol hydrogel synthesis using near infrared light

Science.gov (United States)

Chung, Solchan; Lee, Hwangjae; Kim, Hyung-Seok; Kim, Min-Gon; Lee, Luke P.; Lee, Jae Young

2016-07-01

Light-induced polymerization has been widely applied for hydrogel synthesis, which conventionally involves the use of ultraviolet or visible light to activate a photoinitiator for polymerization. However, with these light sources, transdermal gelation is not efficient and feasible due to their substantial interactions with biological systems, and thus a high power is required. In this study, we used biocompatible and tissue-penetrating near infrared (NIR) light to remotely trigger a thiol-acrylate reaction for efficient in vivo gelation with good controllability. Our gelation system includes gold nanorods as a photothermal agent, a thermal initiator, diacrylate polyethylene glycol (PEG), and thiolated PEG. Irradiation with a low-power NIR laser (0.3 W cm-2) could induce gelation via a mixed-mode reaction with a small increase in temperature (~5 °C) under the optimized conditions. We also achieved successful transdermal gelation via the NIR-assisted photothermal thiol-acryl reactions. This new type of NIR-assisted thiol-acrylate polymerization provides new opportunities for in situ hydrogel formation for injectable hydrogels and delivery of drugs/cells for various biomedical applications.Light-induced polymerization has been widely applied for hydrogel synthesis, which conventionally involves the use of ultraviolet or visible light to activate a photoinitiator for polymerization. However, with these light sources, transdermal gelation is not efficient and feasible due to their substantial interactions with biological systems, and thus a high power is required. In this study, we used biocompatible and tissue-penetrating near infrared (NIR) light to remotely trigger a thiol-acrylate reaction for efficient in vivo gelation with good controllability. Our gelation system includes gold nanorods as a photothermal agent, a thermal initiator, diacrylate polyethylene glycol (PEG), and thiolated PEG. Irradiation with a low-power NIR laser (0.3 W cm-2) could induce gelation

Preparation and characterization of emulsifier-free polyphenylsilsesquioxane-poly (styrene–butyl acrylate) hybrid particles

Energy Technology Data Exchange (ETDEWEB)

Bai, Ruiqin; Qiu, Teng, E-mail: qiuteng@mail.buct.edu.cn; Han, Feng; He, Lifan; Li, Xiaoyu, E-mail: lixy@mail.buct.edu.cn

2013-10-01

The core–shell polyphenylsilsesquioxane-poly (styrene–butyl acrylate) hybrid latex paticles with polyphenylsilsesquioxane as core and poly (styrene–butyl acrylate) as shell were successfully synthesized by seeded emulsion polymerization using polyphenylsisesquioxane (PPSQ) latex particles as seeds. X-ray diffraction (XRD) indicated that the polyphenylsilsesquioxane (PPSQ) had ladder structure, and PPSQ had incorporated into the hybrid latex particles. Transmission electron microscopy (TEM) confirmed that the resultant hybrid latex particles had the core–shell structure. TEM and dynamic light scattering (DLS) analysis indicated that the polyphenylsisesquioxane latex particles and obtained core–shell hybrid latex particles were uniform and possessed narrow size distributions. X-ray photoelectron spectroscopy (XPS) analysis also indicated that the PPSQ core particles were enwrapped by the polymer shell. In addition, compared with pure poly (styrene–butyl acrylate) latex film, the polyphenylsilsesquioxane-poly (styrene–butyl acrylate) hybrid latex film exhibited lower water uptake, higher pencil hardness and better thermal stability.

Extraction of metal cations by polyterephthalamide microcapsules containing a poly(acrylic acid) gel.

Science.gov (United States)

Laguecir, A; Ernst, B; Frère, Y; Danicher, L; Burgard, M

2002-01-01

Polyterephthalamide microcapsules containing a poly(acrylic acid) gel as a macromolecular ligand (PAA-CAPS) were prepared using an original two step polymerization process in a water-in-oil inverse emulsion system. A polyamide microcapsule containing acrylic acid, initiator and cross-linking agent, is formed by interfacial polycondensation of terephthaloyl dichloride with hexamethylenediamine. In situ radical polymerization of the microcapsule core acrylic acid is initiated to obtain encapsulated poly(acrylic acid) gel. Reference polyamide microcapsules, i.e. without ligand (CAPS), were also synthesized. The mean diameter of synthesized microcapsules was 210 microm, and the microcapsule wall thickness was evaluated by SEM and TEM observations of microcapsule cross-section cuts. The microcapsule water content was determined by thermogravimetric experiments. The extractabilities of Cu(II), Ni(II), Co(II) and Zn(II) into PAA-CAPS were examined. The stripping of the various cations can be promoted in diluted hydrochloric acid solutions.

Preparation, Characterization and Permeation Behavior of Poly(methyl acrylate-Poly(dimethyl siloxane-Poly(methyl acrylate Block Copolymer/Poly(vinyl acetate Blend Membranes

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Mohammad Ali Semsarzadeh

2015-03-01

Full Text Available Structure of polymeric materials is of the most important factors in determination of the characteristics and properties of the membranes. Various research and developments on polymeric membranes confirm the direct correlation between structure-properties of polymeric membranes. In this research, the structural outcome of poly(methyl acrylate-poly(dimethyl siloxane-poly(methyl acrylate/poly(vinyl acetate blend membranes and its relationship with gas permeation behavior of the blends were investigated. The flexible block copolymer of poly(methyl acrylate-poly(dimethyl siloxane-poly(methyl acrylate (PMA-PDMS-PMA was synthesized via atom transfer radical polymerization. Morphology and chemical structure of the synthesized block copolymer was investigated by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, gel permeation chromatography, X-ray diffraction analysis, differential scanning calorimetry and scanning electron microscopy. Blend membranes of PMA-PDMS-PMA and poly(vinyl acetate (PVAc were prepared by solution casting method in different compositions. By adding poly(vinyl acetate to PMA-PDMS-PMA block copolymer, the selectivity of the membranes for carbon dioxide/methane pair gases were increased by 55%. Fractional free volume (an indication of chain packing efficiency in blend membranes and dielectric constant (an indication of the molar volume and molar polarization of the blend membranes were obtained as the factors reflected the microstructural effect of PMA-PDMS-PMA and PVAc blend membranes. The efforts were directed toward expressing more precise structure-properties relationship of PMA-PDMS-PMA/PVAc blend membranes. The experimental permeability values of the blend membranes reported in this research were compared with the modified logarithmic model. The modified logarithmic model was evaluated for other blend membranes.

Clinical assessment of diclofenac sodium eye drops in toric intraocular lens implantation

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Yan Luo

2013-05-01

Full Text Available AIM:To evaluate the application of diclofenac sodium eye drops in toric intraocular lens implantation. METHODS: From January 2011 to February 2012, 38 eyes of 37 patients, who underwent toric intraocular lens implantation in this hospital, were randomly divided into diclofenac sodium eye drops group(trial groupand control group. Patient's degree of cooperation during surgery and inflammation postoperation after 1 day, 3,7, days, 1 month and 3 months were evaluated. RESULTS: Patient's degree of cooperation during surgery in the trial group(1.53±0.62was significantly better than in the control group(2.40±0.88, P<0.05. Inflammation reaction was gentle in the trial group 1 day postoperatively. CONCLUSION: Diclofenac sodium eye drops used during toric intraocular lens implantation can obviously alleviate eye irritation, and increase the cooperation of patients.

Peculiarities of the photoinitiator-free photopolymerization of pentabrominated and pentafluorinated aromatic acrylates and methacrylates.

Science.gov (United States)

Daikos, Olesya; Naumov, Sergej; Knolle, Wolfgang; Heymann, Katja; Scherzer, Tom

2016-11-30

Pentabrominated and fluorinated aromatic (meth)acrylates as well as their non-halogenated counterparts have been studied with the aim to avoid conventional photoinitiators and to overcome some negative consequences related to their use. Therefore, RTIR spectroscopy, laser flash photolysis and GC/MS were utilized. Even low concentrations (1 to 5 wt%) of brominated (meth)acrylates in the model varnish lead to initiation of a photopolymerization reaction under exposure to UV light with λ > 300 nm. This is due to the fact that excitation of the aryl moiety leads to the homolysis of bromine-phenyl bonds with a high quantum yield of ∼0.15-0.3. Both, bromine radicals released from either ortho, meta or para position as well as the corresponding tetrabromoaryl radicals, may initiate the polymerization of brominated aromatic (meth)acrylates. In contrast, fluorinated aromatic (meth)acrylates undergo α-cleavage of the carboxyl group (as in the case of non-halogenated aromatic (meth)acrylates), if excitation of the acrylic double bonds is done with UV-C light (λ fluorinated) and 0.16-0.36 (non-halogenated compounds), despite the different pathway of fragmentation. Thus, in all cases the efficiency of initiation is comparable to conventional photoinitiators. Quantum chemical calculations of orbitals involved and of the Gibbs free energy of transients and products support the suggested reaction pathway.

Steel Protective Coating Based on Plasticized Epoxy Acrylate Formulation Cured by Electron Beam Irradiation

International Nuclear Information System (INIS)

Ibrahim, M.S.; Said, H.M.; Mohamed, I.M.; Mohamed, H.A.; Kandile, N.G.

2011-01-01

Electron beam (EB) was used to cure coatings based on epoxy acrylate oligomer (EA) and different plasticizers such as epoxidized soybean oil, glycerol and castor oil. The effect of irradiation doses (10, 25, 50 kGy) on the curing epoxy acrylate formulations containing plasticizers was studied. In the addition, the effect of the different plasticizers on the end use performance properties of epoxy acrylate coatings such as hardness, bending, adhesion, acid and alkali resistance tests were investigated. It was observed that the incorporation of castor oil in epoxy acrylate, diluted by 1,6 hexandiol diacrylate monomer (HD) with a ratio (EA 70%, HD 20%, castor oil 10%) under the dose 10 kGy improved the physical, chemical and mechanical properties of cured films than the other plasticizers. On the other hand, sunflower free fatty acids were epoxidized in-situ under well established conditions and then was subjected to react with aniline in sealed ampoules under inert atmosphere at 140 degree C. The produced adduct was added at different concentrations to epoxy acrylate coatings under certain EB irradiation dose and then evaluated as corrosion inhibitors for carbon steel surfaces in terms of weight loss measurements and corrosion resistance tests. It was observed that the formula containing 0.4 gm of aniline adduct / 100 gm epoxy acrylate resin gave the best corrosion protection for carbon steel

The role of pili in Bacillus cereus intraocular infection.

Science.gov (United States)

Callegan, Michelle C; Parkunan, Salai Madhumathi; Randall, C Blake; Coburn, Phillip S; Miller, Frederick C; LaGrow, Austin L; Astley, Roger A; Land, Craig; Oh, So-Young; Schneewind, Olaf

2017-06-01

Bacterial endophthalmitis is a potentially blinding intraocular infection. The bacterium Bacillus cereus causes a devastating form of this disease which progresses rapidly, resulting in significant inflammation and loss of vision within a few days. The outer surface of B. cereus incites the intraocular inflammatory response, likely through interactions with innate immune receptors such as TLRs. This study analyzed the role of B. cereus pili, adhesion appendages located on the bacterial surface, in experimental endophthalmitis. To test the hypothesis that the presence of pili contributed to intraocular inflammation and virulence, we analyzed the progress of experimental endophthalmitis in mouse eyes infected with wild type B. cereus (ATCC 14579) or its isogenic pilus-deficient mutant (ΔbcpA-srtD-bcpB or ΔPil). One hundred CFU were injected into the mid-vitreous of one eye of each mouse. Infections were analyzed by quantifying intraocular bacilli and retinal function loss, and by histology from 0 to 12 h postinfection. In vitro growth and hemolytic phenotypes of the infecting strains were also compared. There was no difference in hemolytic activity (1:8 titer), motility, or in vitro growth (p > 0.05, every 2 h, 0-18 h) between wild type B. cereus and the ΔPil mutant. However, infected eyes contained greater numbers of wild type B. cereus than ΔPil during the infection course (p ≤ 0.05, 3-12 h). Eyes infected with wild type B. cereus experienced greater losses in retinal function than eyes infected with the ΔPil mutant, but the differences were not always significant. Eyes infected with ΔPil or wild type B. cereus achieved similar degrees of severe inflammation. The results indicated that the intraocular growth of pilus-deficient B. cereus may have been better controlled, leading to a trend of greater retinal function in eyes infected with the pilus-deficient strain. Although this difference was not enough to significantly alter the severity

Synthesis of epoxidised soya bean oil acrylate

International Nuclear Information System (INIS)

Hussin bin Mohd Nor; Mohamad Hilmi bin Mahmood; Dahlan bin Haji Mohd.

1988-10-01

An epoxy acrylate was synthesized from Asahi's epoxy resin AER 331 which is an epoxidised soya bean oil (ESBO). Triethylamine (TEA) and Hydroquinone (HQ) were used as catalyst and inhibitor respectively. Observations of the experiment are described. (author)

Assessment of surface hardness of acrylic resins submitted to accelerated artificial aging.

Science.gov (United States)

Tornavoi, D C; Agnelli, J A M; Lepri, C P; Mazzetto, M O; Botelho, A L; Soares, R G; Dos Reis, A C

2012-06-01

The aim of this study was to assess the influence of accelerated artificial aging (AAA) on the surface hardness of acrylic resins. The following three commercial brands of acrylic resins were tested: Vipi Flash (autopolymerized resin), Vipi Wave (microwave heat-polymerized resin) and Vipi Cril (conventional heat-polymerized resin). To perform the tests, 21 test specimens (65x10x3 mm) were made, 7 for each resin. Three surface hardness readings were performed for each test specimen, before and after AAA, and the means were submitted to the following tests: Kolmogorov-Smirnov (P>0.05), Levene Statistic, Two-way ANOVA, Tukey Post Hoc (Paging, the autopolymerized acrylic resin Vipi Flash showed lower hardness values when compared with the heat-polymerized resin Vipi Cril (P=0.001). After aging, the 3 materials showed similar performance when compared among them. The Vipi Cril was the only one affected by AAA and showed lower hardness values after this procedure (Pp=0.003). It may be concluded that accelerated artificial aging influenced surface hardness of heat-polymerized acrylic resin Vipi Cril.

Long-Chain Diacrylate Crosslinkers and Use of PEG Crosslinks in Poly(potassium acrylate-acrylic acid/Kaolin Composite Superabsorbents

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Koroush Kabiri

2013-01-01

Full Text Available Long-chain diacrylate crosslinkers based on linear α,ω-diols were synthesized and characterized using FTIR and 1H NMR spectroscopy. The highest reaction yield (99.5% was due to polyethylene glycol diacrylate 1000 (PEGDA-1000. Then, kaolin-containing poly(potassium acrylate-acrylic acid superabsorbent composites and kaolin-free counterparts were synthesized using PEGDA-1000.The effect of the crosslinker concentration on swelling, rheological and thermo-mechanical properties was investigated. Absorption capacity of the composite hydrogels (having ~38% kaolin was unexpectedly higher than that of kaolin-free hydrogels. This was attributed to an interfering effect of kaolin during the polymerization. Glass transition temperature was increased with crosslinker concentration enhancement and addition of kaolin up to about 10oC and 28oC, respectively. Making such K-containing superabsorbents may be taken as an effective action to achieve more durable and cheaper superabsorbents for agricultural uses.

Evaluation of hydrophobicity in PAH-contaminated soils during phytoremediation

International Nuclear Information System (INIS)

Cofield, Naressa; Banks, M. Katherine; Schwab, A. Paul

2007-01-01

The impact of recalcitrant organic compounds on soil hydrophobicity was evaluated in contaminated soil from a manufactured gas plant site following 12 months of phytoremediation. Significant reduction in soil wetting and water retention was observed in contaminated soil compared to an uncontaminated control. Phytoremediation was effective at reducing total PAHs by 69% with corresponding changes in soil classification from extremely hydrophobic (initial sample) to moderately-strongly hydrophobic (planted) and hydrophilic-very hydrophilic (unplanted) after 12 months. The greatest reduction in soil hydrophobicity was observed in the unplanted, unfertilized treatments that had the lowest removal rate of PAHs. The presence of plants may contribute to hydrophobicity in contaminated soil. - The presence of recalcitrant hydrophobic organic pollutants may enhance soil hydrophobicity

Preparation and Characterization of Acrylic Primer for Concrete Substrate Application

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El-Sayed Negim

2016-01-01

Full Text Available This study dealt with the properties of acrylic primer for concrete substrate using acrylic syrup, made from a methyl methacrylate monomer solution of terpolymers. Terpolymer systems consisting of methyl methacrylate (MMA, 2-ethylhexyl acrylate (2-EHA, and methacrylic acid (MAA with different chemical composition ratios of MMA and 2-EHA were synthesized through bulk polymerization using azobisisobutyronitrile (AIBN as initiator. The terpolymer composition is characterized by FTIR, 1H NMR, DSC, TGA, and SEM. The glass transition temperature and the thermal stability increased with increasing amounts of MMA in the terpolymer backbone. The effect of chemical composition of terpolymers on physicomechanical properties of primer films was investigated. However, increasing the amount of MMA in terpolymer backbone increased tensile and contact angle of primer films while elongation at break, water absorption, and bond strength are decreased. In particular, the primer syrup containing 65% 2-EHA has good bonding strength with concrete substrate around 1.1 MPa.

Strong composition dependence of adhesive properties of ultraviolet curing adhesives with modified acrylates

Science.gov (United States)

Feng, Yefeng; Li, Yandong; Wang, Fupeng; Peng, Cheng; Xu, Zhichao; Hu, Jianbing

2018-05-01

Ultraviolet (UV) curable adhesives have been widely researched in fields of health care and electronic components. UV curing systems with modified acrylic ester prepolymers have been frequently employed. In order to clarify composition dependence of adhesive properties of adhesives containing modified acrylates, in this work, several UV curing adhesives bearing urethane and epoxy acrylates were designed and fabricated. The effects of prepolymer, diluent, feed ratio, initiator and assistant on adhesive performances were investigated. This work might offer a facile route to gain promising high-performance UV curable adhesives with desired adhesive traits through regulating their compositions.

Environmental Impacts on the Strength Parameters of Mineral-Acrylic (PMMA/ATH Facade Panels

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Aleksander Byrdy

2015-01-01

Full Text Available Composite mineral-acrylic panels consist in 80% of natural minerals produced from bauxite (aluminium hydroxides (ATH and in 20% from acrylic resin (polymethyl methacrylate (PMMA. This material due to high usability is widely used in interior finishes. Recently, the mineral-acrylic panels have been used as external claddings of buildings. So far, there are several dozen elevations realized worldwide. Due to the variability of the strength parameters of PMMA acrylic resins depending on the environmental influence, a number of tests on samples of mineral-acrylic panels to verify their suitability for use in climate conditions in Central Europe were performed. The studies determined the change of the material parameters after being subjected to aging process in conditions of high temperature, high relative humidity, freeze-thaw cycles, and UV radiation. In the studies parameters such as flexural strength and modulus of elasticity were measured at a reference temperature of 23°C. In raised and lowered temperatures only the tensile strength tests were conducted. Due to the lack of information in the available literature, the authors carried out tests of the temperature influence on the PMMA/ATH composite modulus of elasticity and flexural strength which is crucial in designing process.

Immobilization of Gibberella fujikuroi cells with carriers modified by radiation polymerization

International Nuclear Information System (INIS)

Lu Zhaoxin; Xie Zhongchuan; Wei Qijiang

1994-01-01

Gibberella fujikuroi cells were immobilized on modified carriers (gauze) by using the radiation polymerization technique. The mycelium was firmly adhered to the surface of fibril covered with hydrophobic polymer, poly (diethylene glycol dimethyl acrylate) and hydrophobic-hydrophilic copolymer poly (diethylene glycol dimethyl acrylate-sodium acrylate), but it was not immobilized onto the polyethylene net, which has a similar network structure to that of the modified carrier. The weight of immobilized cells was affected by covered polymer. Gibberellic acid productivity in immobilized cells was similar to that of free cells, and the immobilized cells was of good stability. A optimum culture condition for gibberellic acid production was at pH 5.5 and under 20 ∼ 30 degree C

Locally Advanced Basal Cell Carcinoma with Intraocular Invasion

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Georgi Tchernev

2018-01-01

Full Text Available We present a 103 - year - old patient, with duration of complaints of about ten years. The initial complaint had been presented as a small nodule, located on the eyebrow, which subsequently ulcerated and encompassed larger regions of the upper and lower eyelids. For the past three years, the patient also had complaints of a worsening of his vision, without seeking for medical help. Within the dermatological examination, an intraocular and periocular localised tumour was established, characterised by a raised peripheral edge and central ulceration. More careful examination revealed that the bulb was fully consumed. The patient refused further diagnosis and treatment. Advanced basal cell carcinomas with intraocular invasion are rare in general. If the patient refuses surgery, radiotherapy and systemic therapy with modern medications such as Vismodegib or Sonidegib are available as treatment options.

Development of radiation curable surface coating based on soybean oil. part I. preparation and characterization of acrylated oil

International Nuclear Information System (INIS)

Ibrahim, M.S.; Said, H.M.; Moussa, I.M.

2005-01-01

An epoxy acrylate was synthesized from epoxidized soybean oil (ESOL) by using acrylic acid monomer. Triethyl amine (TEA) and hydroquinone were used as catalyst and inhibitor respectively. The epoxidized soybean oil acrylate (ESOLA) is done by introducing acrylic acid into oxirane groups of the epoxidized oil (ESOL). This reaction was confirmed by analytical data in terms of oxirane oxygen content, acid value, viscosity and spectroscopically analysis

Experimental Study of gas-liquid two-phase flow affected by wall surface wettability

International Nuclear Information System (INIS)

Takamasa, T.; Hazuku, T.; Hibiki, T.

2008-01-01

To evaluate the effect of wall surface wettability on the characteristics of upward gas-liquid two-phase flow in a vertical pipe, an experimental study was performed using three test pipes: an acrylic pipe, a hydrophilic pipe and a hydrophobic pipe. Basic flow characteristics such as flow patterns, pressure drop and void fraction were measured in these three pipes. In the hydrophilic pipe, a slug to churn flow transition boundary was shifted to a higher gas velocity at a given liquid velocity, whereas a churn to annular flow transition boundary was shifted to a lower gas velocity at a given liquid velocity. In the hydrophobic pipe, an inverted-churn flow regime was observed in the region where the churn flow regime was observed in the acrylic pipe, while a droplet flow regime was observed in the region where an annular flow regime was observed in the acrylic pipe. At a high gas flow rate, the mean void fraction in the hydrophobic pipe was higher than in the acrylic pipe. The effect of surface wettability on frictional pressure loss was confirmed to be insignificant under the present experimental conditions

SYNTHESIS AND CHARACTERIZATION OF ACRYLATED PARKIA ...

African Journals Online (AJOL)

a

successfully be used to modify alkyd resins yielding acrylated resins with ... superstructure of ships, the paint is also in addition to the above exposed to wind driven salt ... possibility of combining the desirable application and film forming properties of .... Then the temperature was further increased to 230 oC and the reaction.

Comparative Evaluation of Effect of Water Absorption on the Surface Properties of Heat Cure Acrylic: An in vitro Study

OpenAIRE

Chandu, G S; Asnani, Pooja; Gupta, Siddarth; Faisal Khan, Mohd.

2015-01-01

Background: Use of alkaline peroxide denture cleanser with different temperature of water could cause a change in surface hardness of the acrylic denture and also has a bleaching effect. The purpose of the study was to determine the effect of increased water content during thermal cycling of hot water-treated acrylic on the surface hardness of acrylic denture base when compared to warm water treated acrylic. And to compare the bleaching effect of alkaline peroxide solution on the acrylic dent...

Deep UV patterning of acrylic masters for molding biomimetic dry adhesives

International Nuclear Information System (INIS)

Sameoto, D; Menon, C

2010-01-01

We present a novel fabrication method for the production of biomimetic dry adhesives that allows enormous variation in fiber shapes and sizes. The technology is based on deep-UV patterning of commercial acrylic with semi-collimated light available from germicidal lamps, and combined careful processing conditions, material selection and novel developer choices to produce relatively high-aspect-ratio fibers with overhanging caps on large areas. These acrylic fibers are used as a master mold for subsequent silicone rubber negative mold casting. Because the bulk acrylic demonstrates little inherent adhesion to silicone rubbers, the master molds created in this process do not require any surface treatments to achieve high-yield demolding of interlocked structures. Multiple polymers can be cast from silicone rubber negative molds and this process could be used to structure smart materials on areas over multiple square feet. Using direct photopatterning of acrylic allows many of the desired structures for biomimetic dry adhesives to be produced with relative ease compared to silicon-based molding processes, including angled fibers and hierarchical structures. Optimized fiber shapes for a variety of polymers can be produced using this process, and adhesion measurements on a well-characterized polyurethane, ST-1060, are used to determine the effect of fiber geometry on adhesion performance

Effect of silver nano particles on flexural strength of acrylic resins.

Science.gov (United States)

Sodagar, Ahmad; Kassaee, Mohammad Zaman; Akhavan, Azam; Javadi, Negar; Arab, Sepideh; Kharazifard, Mohammad Javad

2012-04-01

Poly(methyl methacrylate), PMMA, is widely used for fabrication of removable orthodontic appliances. Silver nano particles (AgNps) have been added to PMMA because of their antimicrobial properties. The aim of this study is to investigate the effect of AgNps on the flexural strength of PMMA. Acrylic liquid containing 0.05% and 0.2% AgNps was prepared for two kinds of acrylic resins: Rapid Repair &Selecta Plus. Two groups without AgNps were used as control groups. For each one, flexural strength was investigated via Three Point Bending method for the 15 acrylic blocks. Two-way ANOVA, one way ANOVA and Tukey tests were used for statistical analysis. Rapid Repair without AgNps showed the highest flexural strength. Addition of 0.05% AgNps to Rapid Repair, significantly decreased its flexural strength while, continuing the addition up to 0.2% increased it nearly up to its primary level. In contrast, addition of AgNps to Selecta Plus increased its flexural strength but addition of 0.05% nano particles was more effective than 0.2%. The effect of AgNps on flexural strength of PMMA depends on several factors including the type of acrylics and the concentrations of nano particles. Copyright © 2011 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Intraocular eyelashes and iris cyst in anterior chamber following penetrating eye injury: a case report

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Sahu S

2017-03-01

Full Text Available Sabin Sahu,1 Lila Raj Puri,1 Sanjay Kumar Singh2 1Department of Ophthalmology, Sagarmatha Choudhary Eye Hospital, Lahan, Siraha, 2Department of Ophthalmology, Biratnagar Eye Hospital, Biratnagar, Nepal Background: The presence of intraocular eyelashes following penetrating eye injury or ocular surgery is relatively uncommon. The response of the eye to intraocular eyelashes is variable. The eyelash may be symptomatic or may remain asymptomatic for long periods. Objective: We report a case with two intraocular eyelashes and an iris cyst after 2 years of asymptomatic period following penetrating eye injury. Case presentation: A 24-year-old male presented with decreased vision in the left eye which he had noticed for the previous 2 weeks. His visual acuity was 6/6 in the right eye and 6/18 in the left eye, improving to 6/9 with -2.5 DC × 140° correction. The intraocular pressure was 12 mmHg in both eyes. On slit-lamp examination, the left eye showed 8 mm linear peripheral corneal opacity nasally, two eyelashes in the superior anterior chamber, and an iris cyst measuring 4 mm × 4 mm in the superior iris. The right eye was normal. Dilated fundus examination of both eyes was normal. The eyelashes and cyst were removed surgically. There were no complications during the 3-month follow-up period. Conclusion: Intraocular implantation of eyelashes following penetrating eye injury can remain asymptomatic for long periods; however, late development of iris cyst may occur. Keywords: intraocular eyelashes, iris cyst, penetrating eye injury

Lentes intraoculares fácicas de câmara posterior

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Mara Barreto Theiss

Full Text Available Resumo O objetivo deste artigo foi reunir estudos que reportam resultados disponíveis na literatura científica, considerando a previsibilidade, segurança, eficácia, e estabilidade das lentes intraoculares fácicas de câmara posterior. E relatar as complicações documentadas para estas lentes. A revisão criteriosa dos estudos publicados na literatura ate o momento revelam resultado satisfatórios quanto à eficácia, elevada previsibilidade, estabilidade e segurança do implante de lente intraocular de câmara posterior, para correção das miopia, hipermetropia e astigmatismo.

MicroRNA profiling in intraocular medulloepitheliomas.

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Deepak P Edward

Full Text Available To study the differential expression of microRNA (miRNA profiles between intraocular medulloepithelioma (ME and normal control tissue (CT.Total RNA was extracted from formalin fixed paraffin embedded (FFPE intraocular ME (n=7 and from age matched ciliary body controls (n=8. The clinical history and phenotype was recorded. MiRNA profiles were determined using the Affymetrix GeneChip miRNA Arrays analyzed using expression console 1.3 software. Validation of significantly dysregulated miRNA was confirmed by quantitative real-time PCR. The web-based DNA Intelligent Analysis (DIANA-miRPath v2.0 was used to perform enrichment analysis of differentially expressed (DE miRNA gene targets in Kyoto Encyclopedia of Genes and Genomes (KEGG pathway.The pathologic evaluation revealed one benign (benign non-teratoid, n=1 and six malignant tumors (malignant teratoid, n=2; malignant non-teratoid, n = 4. A total of 88 miRNAs were upregulated and 43 miRNAs were downregulated significantly (P<0.05 in the tumor specimens. Many of these significantly dysregulated miRNAs were known to play various roles in carcinogenesis and tumor behavior. RT-PCR validated three significantly upregulated miRNAs and three significantly downregulated miRNAs namely miR-217, miR-216a, miR-216b, miR-146a, miR-509-3p and miR-211. Many DE miRNAs that were significant in ME tumors showed dysregulation in retinoblastoma, glioblastoma, and precursor, normal and reactive human cartilage. Enriched pathway analysis suggested a significant association of upregulated miRNAs with 15 pathways involved in prion disease and several types of cancer. The pathways involving significantly downregulated miRNAs included the toll-like receptor (TLR (p<4.36E-16 and Nuclear Factor kappa B (NF-κB signaling pathways (p<9.00E-06.We report significantly dysregulated miRNAs in intraocular ME tumors, which exhibited abnormal profiles in other cancers as well such as retinoblastoma and glioblastoma. Pathway analysis

Effect of autoclave postpolymerization treatments on the fracture toughness of autopolymerizing dental acrylic resins.

Science.gov (United States)

Durkan, Rukiye; Gürbüz, Ayhan; Yilmaz, Burak; Özel, M Birol; Bağış, Bora

2012-06-26

Microwave and water bath postpolymerization have been suggested as methods to improve the mechanical properties of heat and autopolymerizing acrylic resins. However, the effects of autoclave heating on the fracture properties of autopolymerizing acrylic resins have not been investigated. The aim of this study was to assess the effectiveness of various autoclave postpolymerization methods on the fracture properties of 3 different autopolymerizing acrylic resins. Forty-two specimens of 3 different autopolymerizing acrylic resins (Orthocryl, Paladent RR and Futurajet) were fabricated (40x8x4mm), and each group was further divided into 6 subgroups (n=7). Control group specimens remained as processed (Group 1). The first test group was postpolymerized in a cassette autoclave at 135°C for 6 minutes and the other groups were postpolymerized in a conventional autoclave at 130°C using different time settings (5, 10, 20 or 30 minutes). Fracture toughness was then measured with a three-point bending test. Data were analyzed by ANOVA followed by the Duncan test (α=0.05). The fracture toughness of Orthocryl and Paladent-RR acrylic resins significantly increased following conventional autoclave postpolymerization at 130°C for 10 minutes (Pautoclave postpolymerized Futurajet was not significantly different than its control specimens (Pautoclaved at 130°C for 10 minutes. Within the limitations of this study, it can be suggested that autoclave postpolymerization is an effective method for increasing the fracture toughness of tested autoploymerized acrylic resins.

Pressure-induced polymerization of phenoxyethyl acrylate

Energy Technology Data Exchange (ETDEWEB)

Kaminski, K; Wrzalik, R; Paluch, M; Ziolo, J [Institute of Physics, Silesian University, Uniwersytecka 4, 40-007 Katowice (Poland); Roland, C M [Naval Research Laboratory, Chemistry Division, Code 6120, Washington, DC 20375-5342 (United States)

2008-06-18

Polymerization of phenoxyethyl acrylate was induced without catalyst or initiators by the application of hydrostatic pressure at elevated temperature. Broadband dielectric and infrared spectroscopy were employed to follow the course of the reaction, which reached a degree of conversion of 60%. The structure of the obtained polymer was determined from density functional theory calculations.

Carbon fiber reinforced thermoplastic composites from acrylic polymer matrices: Interfacial adhesion and physical properties

Directory of Open Access Journals (Sweden)

H. Kishi

2017-04-01

Full Text Available Acrylic polymers have high potential as matrix polymers for carbon fiber reinforced thermoplastic polymers (CFRTP due to their superior mechanical properties and the fact that they can be fabricated at relatively low temperatures. We focused on improving the interfacial adhesion between carbon fibers (CFs and acrylic polymers using several functional monomers for co-polymerization with methyl methacrylate (MMA. The copolymerized acrylic matrices showed good adhesion to the CF surfaces. In particular, an acrylic copolymer with acrylamide (AAm showed high interfacial adhesive strength with CFs compared to pure PMMA, and a hydroxyethyl acrylamide (HEAA copolymer containing both amide and hydroxyl groups showed high flexural strength of the CFRTP. A 3 mol% HEAA-copolymerized CFRTP achieved a flexural strength almost twice that of pure PMMA matrix CFRTP, and equivalent to that of an epoxy matrix CFRP.

Durability of hydrophobic treatment of concrete

NARCIS (Netherlands)

Vries, J. de; Polder, R.B.; Borsje, H.

1998-01-01

The subject of this study was the performance of hydrophobic treatment to protect concrete against chloride penetration from de-icing salts. Hydrophobic treatment makes a concrete surface absorb less water and less chloride. Test methods and requirements for commercial products were established. In

Influence of gross saponins from tribulus terrestris L on SOD activity and MDA content for chronic high intraocular pressure in rabbit

Directory of Open Access Journals (Sweden)

Nuo Li

2013-05-01

Full Text Available AIM:To observe influence of gross saponins from tribulus terrestris L(GSTTon SOD activity and MDA content for chronic high intraocular pressure in rabbit, and discusses the retina oxidative damage inhibition on chronic high intraocular pressure model of rabbit. METHODS:Totally 24 healthy New Zealand rabbits were randomly divided into 4 groups: normal control group(A group; high intraocular pressure model blank group(B group; high intraocular pressure model with GSTT treated group(C group; high intraocular pressure model with Erigeron brevicapas hand mass(EBHMtreated group(D group. High intraocular pressure model was induced by 20g/L methylcellulose injection into the anterior chamber in B group, C group and D group. D group was injected 5 mg/kg GSTT and C group was injected 4.5mg/kg EBHM and measured intraocular pressure with Schiotz tonometer every day for 4 weeks. The retina tissue superoxide dismutase(SODand maleic dialdehyde(MDAcontent were detected 28 days later. RESULTS: After glaucoma model of rabbit eyes were established, the intraocular pressure during observation period was maintained in 32-39mmHg; High intraocular pressure model blank group and normal control group, EBHM treatment group, GSTT treatment group were compared, the differences of retina MDA, SOD content had statistical significance(P0.05; EBHM treatment group, GSTT treatment group and normal control group were compared, the content of MDA in the retina was still slightly higher(P<0.05, the content of SOD slightly lower(P<0.05 CONCLUSION: GSTT can effectively improve the retina SOD activity of chronic high intraocular pressure in rabbit and reduce the content of MDA, which has a protective effect of persistent high intraocular retinal oxidative stress.

Acute Central Retinal Artery Occlusion Associated with Intraocular Silicone Oil Tamponade

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Mehmet Yasin Teke

2012-05-01

Full Text Available Many systemic and ocular factors may cause acute central retinal artery occlusion (CRAO. Herein, we aimed to describe a case of CRAO due to intraocular silicone oil (SO tamponade. To the best of our knowledge, a case like our has not been reported previously. A 58-yearold male patient had undergone combined pars plana vitrectomy-lensectomy and intraocular SO for lens luxation and vitreus hemorrhage associated with a blunt ocular trauma in his right eye. Two weeks after the surgery, he presented with acute vision loss in the same eye. He was diagnosed with acute CRAO and it should be related with mechanical press or raised intraocular pressure (IOP associated with SO. He was treated by partial removal of SO immediately. In spite of the regression of retina edema, his visual acuity did not improve due to optic atrophy. SO may cause CRAO due to raised IOP and/or its mechanical pressure and this complication must be kept in mind. (Turk J Oph thal mol 2012; 42: 238-40

Advanced pigment dispersion glaucoma secondary to phakic intraocular collamer lens implant.

Science.gov (United States)

Ye, Clara; Patel, Cajal K; Momont, Anna C; Liu, Yao

2018-06-01

We report a case of pigment dispersion glaucoma secondary to uncomplicated phakic intraocular collamer lens (ICL) (Visian ICL™, Staar Inc., Monrovia, CA) implant that resulted in advanced visual field loss. A 50-year-old man presented for routine follow-up status post bilateral phakic intraocular collamer lens (ICL) placement 8 years earlier. He was incidentally found to have a decline in visual acuity from an anterior subcapsular cataract and elevated intraocular pressure (IOP) in the left eye. There were signs of pigment dispersion and no evidence of angle closure. Diffuse optic nerve thinning was consistent with advanced glaucomatous visual field defects. Pigment dispersion was also present in the patient's right eye, but without elevated IOP or visual field defects. The patient was treated with topical glaucoma medications and the phakic ICL in the left eye was removed concurrently with cataract surgery to prevent further visual field loss. Pigment dispersion glaucoma is a serious adverse outcome after phakic ICL implantation and regular post-operative monitoring may prevent advanced visual field loss.

Ocular Onchocerciasis in the Yanomami Communities from Brazilian Amazon: Effects on Intraocular Pressure

OpenAIRE

Herzog-Neto, Guilherme; Jaegger, Karen; do Nascimento, Erika S.; Marchon-Silva, Verônica; Banic, Dalma M.; Maia-Herzog, Marilza

2014-01-01

To determine the influence of onchocercal eye disease on the intraocular pressure of the Yanomami Tribe Aratha-ú of Roraima State, Brazil, considered endemic for onchocerciasis, a total of 86 patients were submitted to an ophthalmologic exam that included external examination, slit lamp examination, intraocular pressure measurement, and a fundus ophthalmoscope examination. A high prevalence of onchocerciasis-related eye lesions was encountered in 68.6% of the patients. Punctate keratitis and ...

Intraocular osseous metaplasia. A clinico-pathological study.

Science.gov (United States)

Vemuganti, Geeta K; Honavar, Santosh G; Jalali, Subhadra

2002-09-01

To evaluate the clinico-pathologic features of intraocular osseous metaplasia. Pathology specimens of enucleated eyes submitted to the ophthalmic pathology service at a tertiary eye-care referral center between January 1995 and June 1999 were studied for intraocular osseous metaplasia. Specific histopathologic features noted in specimens with osseous metaplasia were the presence of retinal detachment, gliosis, retinal pigment epithelial hyperplasia, drusen, epiretinal membrane, fibrovascular proliferation and inflammation. Immunohistochemistry using monoclonal antibody against glial fibrillary acidic protein was performed to assess the glial component within the membranes and the proliferative vitreoretinal mass. Clinical records were reviewed and correlated with histopathologic findings. Osseous metaplasiaS was noted in 8 of 151 (5.2%) eyes examined. Clinical diagnosis in these was phthisis bulbi, staphyloma, absolute glaucoma and microphthalmos. Enucleation was performed for relief of symptoms (in painful blind eyes) or for cosmesis, and in an eye inciting sympathetic ophthalmia. Retinal detachment, gliosis and retinal pigment epithelial hyperplasia were noted in all the cases. Drusen with calcification or ossification (5 of 8), fibrovascular proliferation in the vitreous (5 of 8) and active inflammation (4 of 8) were the other associated histologic features. Location of ossification was subretinal in 3 cases, preretinal (ora serrata) in 1 case and in both locations in 4 cases. The eyes with subretinal osseous metaplasia had associated calcified drusen, while preretinal ossification was seen within the fibrovascular membranes. Chronic retinal detachment, hyperplasia and transdifferentiation of retinal pigment epithelium appear to be a few of the prerequisites for intraocular osseous metaplasia. Ossification can occur at isolated subretinal and preretinal locations or can involve both. Though a larger study is required to postulate the chronology of events, in

Intraocular osseous metaplasia. A clinico-pathological study

Directory of Open Access Journals (Sweden)

Vemuganti Geeta

2002-01-01

Full Text Available Purpose: To evaluate the clinico-pathologic features of intraocular osseous metaplasia. Methods: Pathology specimens of enucleated eyes submitted to the ophthalmic pathology service at a tertiary eye-care referral center between January 1995 and June 1999 were studied for intraocular osseous metaplasia. Specific histopathologic features noted in specimens with osseous metaplasia were the presence of retinal detachment, gliosis, retinal pigment epithelial hyperplasia, drusen, epiretinal membrane, fibrovascular proliferation and inflammation. Immunohistochemistry using monoclonal antibody against glial fibrillary acidic protein was performed to assess the glial component within the membranes and the proliferative vitreoretinal mass. Clinical records were reviewed and correlated with histopathologic findings. Results: Osseous metaplasiaS was noted in 8 of 151 (5.2% eyes examined. Clinical diagnosis in these was phthisis bulbi, staphyloma, absolute glaucoma and microphthalmos. Enucleation was performed for relief of symptoms (in painful blind eyes or for cosmesis, and in an eye inciting sympathetic ophthalmia. Retinal detachment, gliosis and retinal pigment epithelial hyperplasia were noted in all the cases. Drusen with calcification or ossification (5 of 8, fibrovascular proliferation in the vitreous (5 of 8 and active inflammation (4 of 8 were the other associated histologic features. Location of ossification was subretinal in 3 cases, preretinal (ora serrata in 1 case and in both locations in 4 cases. The eyes with subretinal osseous metaplasia had associated calcified drusen, while preretinal ossification was seen within the fibrovascular membranes. Conclusion: Chronic retinal detachment, hyperplasia and transdifferentiation of retinal pigment epithelium appear to be a few of the prerequisites for intraocular osseous metaplasia. Ossification can occur at isolated subretinal and preretinal locations or can involve both. Though a larger study is

Durability of hydrophobic treatment of concrete

NARCIS (Netherlands)

Vries, J. de; Polder, R.B.; Borsje, H.

1998-01-01

The subject of this study was the performance of hydrophobic treatment to protect concrete against chloride penetration from de-icing salts. Hydrophobic treatment makes a concrete surface absorb less water and less chloride. Several types of tests were carried out to study the performance of

On the retinal toxicity of intraocular glucocorticoids.

Science.gov (United States)

Torriglia, Alicia; Valamanesh, Fatemeh; Behar-Cohen, Francine

2010-12-15

Corticosteroids are hormones involved in many physiological responses such as stress, immune modulation, protein catabolism and water homeostasis. The subfamily of glucocorticoids is used systemically in the treatment of inflammatory diseases or allergic reactions. In the eye, glucocorticoides are used to treat macular edema, inflammation and neovascularization. The most commonly used glucocorticoid is triamcinolone acetonide (TA). The pharmaceutical formulation of TA is not adapted for intravitreal administration but has been selected by ophthalmologists because its very low intraocular solubility provides sustained effect. Visual benefits of intraocular TA do not clearly correlate with morpho-anatomical improvements, suggesting potential toxicity. We therefore studied, non-common, but deleterious effects of glucocorticoids on the retina. We found that the intravitreal administration of TA is beneficial in the treatment of neovascularization because it triggers cell death of endothelial cells of neovessels by a caspase-independent mechanism. However, this treatment is toxic for the retina because it induces a non-apoptotic, caspase-independent cell death related to paraptosis, mostly in the retinal pigmented epithelium cells and the Müller cells. Copyright © 2010 Elsevier Inc. All rights reserved.

Elastic modulus and flexural strength comparisons of high-impact and traditional denture base acrylic resins

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Nour M. Ajaj-ALKordy

2014-01-01

Conclusion: Within the limitations of this study, it can be concluded that the high-impact acrylic resin is a suitable denture base material for patients with clinical fracture of the acrylic denture.

Dewetting and Hydrophobic Interaction in Physical and Biological Systems

Science.gov (United States)

Berne, Bruce J.; Weeks, John D.; Zhou, Ruhong

2013-01-01

Hydrophobicity manifests itself differently on large and small length scales. This review focuses on large length scale hydrophobicity, particularly on dewetting at single hydrophobic surfaces and drying in regions bounded on two or more sides by hydrophobic surfaces. We review applicable theories, simulations and experiments pertaining to large scale hydrophobicity in physical and biomoleclar systems and clarify some of the critical issues pertaining to this subject. Given space constraints, we could not review all of the significant and interesting work in this very active field. PMID:18928403

Retropupillary Fixation of Iris-Claw Intraocular Lens for Aphakic Eyes in Children.

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Martina Brandner

Full Text Available To report outcome, complications and safety of retropupillary fixated iris-claw intraocular lenses in a pediatric population.Retrospective study.Ten consecutive pediatric patients (15 eyes underwent placement of retropupillary fixated iris-claw intraocular lenses between October 2007 and July 2013 at the Department of Ophthalmology, Medical University Graz and General Hospital Klagenfurt, Austria. Postoperative visual acuity and complications were analyzed.Median final best-corrected visual acuity improved by 0.12 logMAR from preoperative baseline. Mean postoperative spherical equivalent was -0.05 ± 1.76 D. No serious complications were observed intra- or postoperatively during the entire follow-up period of up to 40 months. One patient experienced a haptic disenclavation with IOL subluxation immediately after a car accident.Our study demonstrates that iris-claw intraocular lens implantation behind the iris is safe in children with lack of capsular support and yields excellent visual outcome with low complication rate.

Retropupillary Fixation of Iris-Claw Intraocular Lens for Aphakic Eyes in Children

Science.gov (United States)

Brandner, Martina; Thaler-Saliba, Sarah; Plainer, Sophie; Vidic, Bertram; El-Shabrawi, Yosuf; Ardjomand, Navid

2015-01-01

Purpose To report outcome, complications and safety of retropupillary fixated iris-claw intraocular lenses in a pediatric population. Design Retrospective study. Patients and Methods Ten consecutive pediatric patients (15 eyes) underwent placement of retropupillary fixated iris-claw intraocular lenses between October 2007 and July 2013 at the Department of Ophthalmology, Medical University Graz and General Hospital Klagenfurt, Austria. Postoperative visual acuity and complications were analyzed. Results Median final best-corrected visual acuity improved by 0.12 logMAR from preoperative baseline. Mean postoperative spherical equivalent was -0.05 ± 1.76 D. No serious complications were observed intra- or postoperatively during the entire follow-up period of up to 40 months. One patient experienced a haptic disenclavation with IOL subluxation immediately after a car accident. Conclusion Our study demonstrates that iris-claw intraocular lens implantation behind the iris is safe in children with lack of capsular support and yields excellent visual outcome with low complication rate. PMID:26110864

Anti-tubercular therapy for intraocular tuberculosis: A systematic review and meta-analysis.

Science.gov (United States)

Kee, Ae Ra; Gonzalez-Lopez, Julio J; Al-Hity, Aws; Gupta, Bhaskar; Lee, Cecilia S; Gunasekeran, Dinesh Visva; Jayabalan, Nirmal; Grant, Robert; Kon, Onn Min; Gupta, Vishali; Westcott, Mark; Pavesio, Carlos; Agrawal, Rupesh

2016-01-01

Intraocular tuberculosis remains a diagnostic and management conundrum for both ophthalmologists and pulmonologists. We analyze the efficacy and safety of anti-tubercular therapy (ATT) in patients with intraocular tuberculosis and factors associated with favorable outcome. Twenty-eight studies are included in this review, with a total of 1,917 patients. Nonrecurrence of inflammation was observed in pooled estimate of 84% of ATT-treated patients (95% CI 79-89). There was minimal difference in the outcome between patients treated with ATT alone (85% successful outcome; 95% CI 25-100) and those with concomitant systemic corticosteroid (82%; 95% CI 73-90). The use of ATT may be of benefit to patients with suspected intraocular tuberculosis; however, this conclusion is limited by the lack of control group analysis and standardized recruitment and treatment protocols. We propose further prospective studies to better establish the efficacy of ATT and ascertain the factors associated with favorable treatment outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

Preparation and magnetic properties of polymer magnetic composites based on acrylate resin filled with nickel plating graphite nanosheets

Energy Technology Data Exchange (ETDEWEB)

Zhang Yi, E-mail: zhangyi520love@yahoo.com.cn [Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi' an 710072 (China); Qi Shuhua; Zhang Fan; Yang Yongqing; Duan Guochen [Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi' an 710072 (China)

2011-11-01

Nickel plating graphite nanosheets (Ni/GNs) were prepared by electroless plating method using graphite nanosheets (GNs). Then a novel polymer magnetic composites based on acrylate pressure-sensitive adhesive (acrylate PSA) filled with Ni/GNs were fabricated by solution blend method. The Ni/GNs and acrylate PSA/Ni/GNs composites were characterized by scanning electron microscope (SEM)/energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and transmission electron microscope (TEM). All results showed that relatively uniform and compact Ni layer is successfully coated onto GNs under the given conditions, furthermore, Ni/GNs are homogeneously dispersed in acrylate PSA. The VSM results showed that the saturation magnetization of acrylate PSA/Ni/GNs composites increases with an increasing content of Ni/GNs while the coercivity decreases with an increasing content of Ni/GNs. When the content of GNs is 20 wt%, acrylate PSA/Ni/GNs composites exhibites good mechanical properties.

Preparation and magnetic properties of polymer magnetic composites based on acrylate resin filled with nickel plating graphite nanosheets

International Nuclear Information System (INIS)

Zhang Yi; Qi Shuhua; Zhang Fan; Yang Yongqing; Duan Guochen

2011-01-01

Nickel plating graphite nanosheets (Ni/GNs) were prepared by electroless plating method using graphite nanosheets (GNs). Then a novel polymer magnetic composites based on acrylate pressure-sensitive adhesive (acrylate PSA) filled with Ni/GNs were fabricated by solution blend method. The Ni/GNs and acrylate PSA/Ni/GNs composites were characterized by scanning electron microscope (SEM)/energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and transmission electron microscope (TEM). All results showed that relatively uniform and compact Ni layer is successfully coated onto GNs under the given conditions, furthermore, Ni/GNs are homogeneously dispersed in acrylate PSA. The VSM results showed that the saturation magnetization of acrylate PSA/Ni/GNs composites increases with an increasing content of Ni/GNs while the coercivity decreases with an increasing content of Ni/GNs. When the content of GNs is 20 wt%, acrylate PSA/Ni/GNs composites exhibites good mechanical properties.

Intraocular pressure menagement with transpalpebral tonometry

OpenAIRE

Toker, Mustafa İlker; Dursun, Ayhan

2013-01-01

Applanation tonometry is the method of measuring intraocular pressure (IOP) with instruments the corneal surface. The Goldmann applanation tonometer (GAT) is regarded as the “gold standard’’ of measuring IOP. An irregular and opaque corneal surface compromises IOP measurement by Goldmann applanation tonometry. In such cases accurate measurement without corneal contact would be applicable. The transpalpebral tonometer is new method and measures IOP without corneal contact through the eyelid....

Liquid-crystal intraocular adaptive lens with wireless control

NARCIS (Netherlands)

Simonov, A.N.; Vdovine, G.V.; Loktev, M.

2007-01-01

We present a prototype of an adaptive intraocular lens based on a modal liquid-crystal spatial phase modulator with wireless control. The modal corrector consists of a nematic liquid-crystal layer sandwiched between two glass substrates with transparent low- and high-ohmic electrodes, respectively.

Clinical analysis of modified trabeculectomy in glaucoma surgery with high elevated intraocular pressure

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Cang-Xia Zhang

2013-10-01

Full Text Available AIM: To make a retrospective analysis of the clinical data of modified trabeculectomy in treating glaucoma surgery with high elevated intraocular pressure retrospectively and evaluate the effect of modified trabeculectomy.METHODS:One hundred acute angle-closure glaucoma patients(100 eyeswith persistent high intraocular pressure were divided into treatment group(45 eyesand control group(55 eyes. Patients in treatment group was treated with by trabeculectomy, while those in control group received modified trabeculectomy. The modified measures include stellate ganglion block preoperative, topical anesthesia and local anesthesia with 20g/L lidocaine cotton-piece, to make scleral flap with sclerotome, to release aqueous humor outflow slowly after paracentesis of anterior chamber, and using mydriatic and cycloplegic during and after surgery.RESULTS: The incidence of operation complicationin control group was lower than that in treatment group. The differences were statistically significant(Pt=9.1535, Pt=39.8010, Pt=11.3219, PCONCLUSION: The modified trabeculectomy applied in the treatment of glaucoma with persistent high intraocular pressure can not only save the visual function of connection part to a certain extent, but also reduce the incidence of serious complications. It can obtain better intraocular pressure, shorten the average hospitalization days, decrease the expenses and increase patients satisfaction.

Formation of Methyl Acrylate from CO 2 and Ethylene via Methylation of Nickelalactones

KAUST Repository

Bruckmeier, Christian

2010-05-24

The nickel-induced coupling of ethylene and CO2 represents a promising pathway toward acrylates. To overcome the high bond dissociation energies of the M-O moieties, we worked out an in situ methylation of nickelalactones to realize the β-hydride elimination and the liberation of the acrylate species. © 2010 American Chemical Society.

The hydrophobic effect: Molecular dynamics simulations of water confined between extended hydrophobic and hydrophilic surfaces

DEFF Research Database (Denmark)

Jensen, Morten Østergaard; Mouritsen, Ole G.; Peters, Günther H.J.

2004-01-01

Structural and dynamic properties of water confined between two parallel, extended, either hydrophobic or hydrophilic crystalline surfaces of n-alkane C36H74 or n-alcohol C35H71OH, are studied by molecular dynamics simulations. Electron density profiles, directly compared with corresponding......-correlation functions reveal that water molecules have characteristic diffusive behavior and orientational ordering due to the lack of hydrogen bonding interactions with the surface. These observations suggest that the altered dynamical properties of water in contact with extended hydrophobic surfaces together...... at both surfaces. The ordering is characteristically different between the surfaces and of longer range at the hydrophilic surface. Furthermore, the dynamic properties of water are different at the two surfaces and different from the bulk behavior. In particular, at the hydrophobic surface, time...

Acrylated Palm Oil Resins for Radiation (UV) Curing of Over Print Varnish (OPV)

International Nuclear Information System (INIS)

Norshamsul Arif; Mohd Hilmi Mahmood; Khairul Zaman Mohd Dahlan; Rosley Che Ismail; Flora Sim; Sharilla Muhammad Faizal

2010-01-01

The purpose of this project was to determine the effects of Acrylated Epoxidized Palm Oil (EPOLA) on a radiation (UV) curing Over Print Varnish (OPV) application. The initial target was to produce an environmentally friendly resin (non-VOC) and reduce the dependence on petroleum (hydrocarbon) based products which are more toxic. Toxicity was determined via Acute Oral Toxicity (LD50), OECD 401 and Acute Toxicity (Dermal), OECD 402 technique whilst the reactivity, chemical resistance and other physical properties were obtained from actual printing application test. The developed EPOLA resin was combined with acrylated monomers, photo initiator(s) and additives in typical OPV formulation before being chemically converted into protective glossy printed film under Ultra Violet (UV-C) light. The gloss, flexibility and adhesion effects are significantly greater than conventional OPV epoxy based coupled with further extremely low irritancy to skin. The contributions of this project are twofold. First, the toxicity of developed acrylated Palm Oil resin is certainly lower than conventional epoxy acrylates resin. Secondly, the benefits towards radiation curing OPV applications were significantly demonstrated. (author)

Acrylic acid surface-modified contact lens for the culture of limbal stem cells.

Science.gov (United States)

Zhang, Hong; Brown, Karl David; Lowe, Sue Peng; Liu, Guei-Sheung; Steele, David; Abberton, Keren; Daniell, Mark

2014-06-01

Surface treatment to a biomaterial surface has been shown to modify and help cell growth. Our aim was to determine the best surface-modified system for the treatment of limbal stem cell deficiency (LSCD), which would facilitate expansion of autologous limbal epithelial cells, while maintaining cultivated epithelial cells in a less differentiated state. Commercially available contact lenses (CLs) were variously surface modified by plasma polymerization with ratios of acrylic acid to octadiene tested at 100% acrylic acid, 50:50% acrylic acid:octadiene, and 100% octadiene to produce high-, mid-, and no-acid. X-ray photoelectron spectroscopy was used to analyze the chemical composition of the plasma polymer deposited layer. Limbal explants cultured on high acid-modified CLs outgrew more cells. Immunofluorescence and RT2-PCR array results indicated that a higher acrylic acid content can also help maintain progenitor cells during ex vivo expansion of epithelial cells. This study provides the first evidence for the ability of high acid-modified CLs to preserve the stemness and to be used as substrates for the culture of limbal cells in the treatment of LSCD.

The effects of barium sufate and iodide compound on the characteristics of dental acrylic resins

International Nuclear Information System (INIS)

Lee, Yong Keun; Lee, Keon Il; Jung, Sung Woo

1996-01-01

Aspiratin or swallowing foreign bodies is a common occurrence. If they are wholly or partly radiopaque, their localization in and progress through the gastrointestinal tract can be more effective. Of the dental origin foreign materials swallowed, the most common things are fragments of anterior maxillary partial denture. But the radiopacity of denture base resins is not sufficient to determine the location of the objects. The purpose of this study was to develop a radiopaque dental acrylic resin, which has clinically detectable radiopacity with minimal change of mechanical properties and color. the radiopacity, color change (CIE E) and microhardness of acrylic resins were determined after mixing barium sulfate or iolide compound. Thermocycling course was conducted to deter mine the change of characteristic of resins after using for a long time I the mouth. Five or ten percent of barium sulfa te to total weight of cured material was mixed with heat curing dental acrylic resin or chemically curing orthodontic re sin. In the case of iodide compound, the mixing ratio was two or three percent. After mixing the high radiopaque material s, resin was cured to 20X20X2 mm plate, polished with 600 sand paper and finally polished with Microcloth (Buehler). T he specimens were thermocycled in 5 and 55 degree distilled water for 2,000 times, and the measurement of radiopacity, color and Vickers hardness was repeated every 500 times thermocycling. The radiopacity of specimens on the X-ray films was measured with densitometer (X-rite). The color change was determined with differential colorimeter (Model TC-6FX, Tokyo Denshoku), and the Vickers hardness number was measured with microhardness tester (Mitsuzawa). The following results were obtained : 1. All the three variables, the kinds of acrylic resins, the mixing or the kinds radiopaque materials and thermocycling , had combined effect on the radiopacity of the dental acrylic resins (p<0.01). 2. The two variables, the mixing or

The effects of barium sufate and iodide compound on the characteristics of dental acrylic resins

Energy Technology Data Exchange (ETDEWEB)

Lee, Yong Keun; Lee, Keon Il; Jung, Sung Woo [Dept. of Oral Radiology, College of Dentistry, Wonkwang University, Iksan(Korea, Republic of)

1996-08-15

Aspiratin or swallowing foreign bodies is a common occurrence. If they are wholly or partly radiopaque, their localization in and progress through the gastrointestinal tract can be more effective. Of the dental origin foreign materials swallowed, the most common things are fragments of anterior maxillary partial denture. But the radiopacity of denture base resins is not sufficient to determine the location of the objects. The purpose of this study was to develop a radiopaque dental acrylic resin, which has clinically detectable radiopacity with minimal change of mechanical properties and color. the radiopacity, color change (CIE E) and microhardness of acrylic resins were determined after mixing barium sulfate or iolide compound. Thermocycling course was conducted to deter mine the change of characteristic of resins after using for a long time I the mouth. Five or ten percent of barium sulfa te to total weight of cured material was mixed with heat curing dental acrylic resin or chemically curing orthodontic re sin. In the case of iodide compound, the mixing ratio was two or three percent. After mixing the high radiopaque material s, resin was cured to 20X20X2 mm plate, polished with 600 sand paper and finally polished with Microcloth (Buehler). T he specimens were thermocycled in 5 and 55 degree distilled water for 2,000 times, and the measurement of radiopacity, color and Vickers hardness was repeated every 500 times thermocycling. The radiopacity of specimens on the X-ray films was measured with densitometer (X-rite). The color change was determined with differential colorimeter (Model TC-6FX, Tokyo Denshoku), and the Vickers hardness number was measured with microhardness tester (Mitsuzawa). The following results were obtained : 1. All the three variables, the kinds of acrylic resins, the mixing or the kinds radiopaque materials and thermocycling , had combined effect on the radiopacity of the dental acrylic resins (p<0.01). 2. The two variables, the mixing or

Synthesis and characterization of amylose grafted poly(acrylic acid) and its application in ammonia adsorption.

Science.gov (United States)

Chen, Qing; Yu, Haojie; Wang, Li; Abdin, Zain-Ul; Yang, Xinpeng; Wang, Junhua; Zhou, Weidong; Zhang, Hongtao; Chen, Xiao

2016-11-20

Amylose grafted poly(acrylic acid) (Am-g-PAA) was synthesized by graft copolymerization of amylose with acrylic acid. The structure of Am-g-PAA was confirmed by (1)H NMR and FT-IR spectra. The morphology, crystallinity and thermal properties of amylose and Am-g-PAA were investigated by SEM, XRD and TGA, respectively. The highest degree of substitution (DS) of carboxyl group was 1.96 which was obtained after reacted for 1h at 60°C. Acrylic acid to anhydroglucose mole ratio for DS was 19.81. It was found that a large number of carboxyl groups were grafted on the backbone of amylose. It was also found that ammonia adsorption capacity of amylose increased by grafting poly(acrylic acid) on the backbone of amylose. Copyright © 2016 Elsevier Ltd. All rights reserved.

Changes in corneal endothelium cell characteristics after cataract surgery with and without use of viscoelastic substances during intraocular lens implantation

Directory of Open Access Journals (Sweden)

Schulze SD

2015-11-01

Full Text Available Stephan D Schulze,1 Thomas Bertelmann,1 Irena Manojlovic,2 Stefan Bodanowitz,2 Sebastian Irle,3 Walter Sekundo11Department of Ophthalmology, Philipps University of Marburg, Marburg, 2Private Practice and Ambulatory Surgical Center, Bremen, 3Freelance Statistician, Friedberg, GermanyPurpose: To evaluate whether the use of balanced salt solution (BSS or an ophthalmic viscoelastic device (OVD during hydrophilic acrylic intraocular lens (IOL implantation variously impacts corneal endothelial cell characteristics in eyes undergoing uneventful phacoemulsifications.Methods: Prospective nonrandomized observational clinical trial. Patients were assigned either to the BSS plus® or to the OVD Z-Celcoat™ group depending on the substance used during IOL implantation. Corneal endothelium cell characteristics were obtained before, 1 week, and 6 weeks after surgery. Intraoperative parameters (eg, surgery time, phacoemulsification energy were recorded.Results: Ninety-seven eyes were assigned to the BSS plus and 86 eyes to the Z-Celcoat group. Preoperative corneal endothelium cell density (ECD and endothelium cell size were 2,506±310 cells/mm2/2,433±261 cells/mm2 and 406±47 µm2/416±50 µm2 (P=0.107/P=0.09. After 1 and 6 weeks, ECD decreased and endothelium cell size increased significantly in both groups (each P<0.001 without significant differences between both groups (each P>0.05. Irrigation–aspiration suction time (30.3±16.6 versus 36.3±14.5 seconds and overall surgical time (7.2±1.2 versus 8.0±1.4 minutes were significantly longer in the OVD Z-Celcoat group (each P<0.001. No complications or serious side effects occurred.Conclusion: Implantation of a hydrophilic acrylic IOL under BSS infusion seems to be a useful and faster alternative in experienced hands without generating higher ECD loss rates.Keywords: phacoemulsification, ophthalmic viscoelastic device, endothelial cell density, IOL

Surface Hydrophobicity Causes SO2 Tolerance in Lichens

Science.gov (United States)

Hauck, Markus; Jürgens, Sascha-René; Brinkmann, Martin; Herminghaus, Stephan

2008-01-01

Background and Aims The superhydrophobicity of the thallus surface in one of the most SO2-tolerant lichen species, Lecanora conizaeoides, suggests that surface hydrophobicity could be a general feature of lichen symbioses controlling their tolerance to SO2. The study described here tests this hypothesis. Methods Water droplets of the size of a raindrop were placed on the surface of air-dry thalli in 50 lichen species of known SO2 tolerance and contact angles were measured to quantify hydrophobicity. Key Results The wettability of lichen thalli ranges from strongly hydrophobic to strongly hydrophilic. SO2 tolerance of the studied lichen species increased with increasing hydrophobicity of the thallus surface. Extraction of extracellular lichen secondary metabolites with acetone reduced, but did not abolish the hydrophobicity of lichen thalli. Conclusions Surface hydrophobicity is the main factor controlling SO2 tolerance in lichens. It presumably originally evolved as an adaptation to wet habitats preventing the depression of net photosynthesis due to supersaturation of the thallus with water. Hydrophilicity of lichen thalli is an adaptation to dry or humid, but not directly rain-exposed habitats. The crucial role of surface hydrophobicity in SO2 also explains why many markedly SO2-tolerant species are additionally tolerant to other (chemically unrelated) toxic substances including heavy metals. PMID:18077467

Changes in intraocular pressure and horizontal pupil diameter ...

African Journals Online (AJOL)

The objective of this study was to determine the effects of topical 0.5% tropicamide, 1% atropine sulphate and 10% phenylephrine hydrochloride ophthalmic solutions on intraocular pressure (IOP) and horizontal pupil diameter (HPD) in the dog during the first hour after treatment. Forty clinically and ophthalmologically ...

Visual outcome with the Oculentis Mplus intraocular lens

Directory of Open Access Journals (Sweden)

Si-Yuan Liu

2017-11-01

Full Text Available AIM: To evaluate the visual outcome of Oculentis Mplus intraocular lens(IOL.METHODS: Totally 20 eyes in 20 patients received phacoemulsification and Oculentis Mplus intraocular lens implantation were as test group, and 20 eyes(Aspira-aA IOLwere as control group. The following postoperative examinations were performed after operation for 3mo: uncorrected visual acuity of distance and near, refractive results, UBM examination, the rate of wearing spectacles and the complications. RESULTS: At 3mo after surgery, distance visual acuity of test group with Oculentis Mplus IOL were 0.10±0.03,the difference with control group was not significant(t=1.74, P>0.05. Eyes in test group had an uncorrected near acuity 0.11±0.04, the difference with control group was significant(t=15.53, PCONCLUSION: The implantation of Oculentis Mplus IOL not only has a good distance uncorrected visual acuity, but also with better near visual acuity. The surgery is safe, reliable and no special complication induced.

An ultralow power wireless intraocular pressure monitoring system

International Nuclear Information System (INIS)

Liu Demeng; Mei Niansong; Zhang Zhaofeng

2014-01-01

This paper describes an ultralow power wireless intraocular pressure (IOP) monitoring system that is dedicated to sensing and transferring intraocular pressure of glaucoma patients. Our system is comprised of a capacitive pressure sensor, an application-specific integrated circuit, which is designed on the SMIC 180 nm process, and a dipole antenna. The system is wirelessly powered and demonstrates a power consumption of 7.56 μW at 1.24 V during continuous monitoring, a significant reduction in active power dissipation compared to existing work. The input RF sensitivity is −13 dBm. A significant reduction in input RF sensitivity results from the reduction of mismatch time of the ASK modulation caused by FM0 encoding. The system exhibits an average error of ± 1.5 mmHg in measured pressure. Finally, a complete IOP system is demonstrated in the real biological environment, showing a successful reading of the pressure of an eye. (semiconductor integrated circuits)

Heat-resistant hydrophobic-oleophobic coatings

OpenAIRE

Uyanik, Mehmet; Arpac, Ertugrul; Schmidt, Helmut K.; Akarsu, Murat; Sayilkan, Funda; Sayilkan, Hikmet

2006-01-01

Thermally and chemically durable hydrophobic oleophobic coatings, containing different ceramic particles such as SiO2, SiC, Al 2O3, which can be alternative instead of Teflon, have been developed and applied on the aluminum substrates by spin-coating method. Polyimides, which are high-thermal resistant heteroaromatic polymers, were synthesized, and fluor oligomers were added to these polymers to obtain hydrophobic-oleophobic properties. After coating, Al surface was subjected to Taber-abrasio...

INTRAOCULAR AND SERUM LEVELS OF VASCULAR ENDOTHELIAL GROWTH FACTOR IN ACUTE RETINAL NECROSIS AND OCULAR TOXOPLASMOSIS

NARCIS (Netherlands)

Wiertz, Karin; De Visser, Lenneke; Rijkers, Ger; De Groot-Mijnes, Jolanda; Los, Leonie; Rothova, Aniki

2010-01-01

Purpose: To determine the intraocular and serum vascular endothelial growth factor (VEGF) levels in patients with acute retinal necrosis (ARN) and compare those with VEGF levels found in patients with ocular toxoplasmosis (OT). Methods: Paired intraocular fluid and serum samples of 17 patients with

Effects of water on starch-g-polystyrene and starch-g-poly(methyl acrylate) extrudates

International Nuclear Information System (INIS)

Henderson, A.M.; Rudin, A.

1982-01-01

Polystyrene and poly(methyl acrylate) were grafted onto wheat starch by gamma radiation and chemical initiation, respectively. The respective percent add-on values were 46 and 45; 68% of the polystyrene formed was grafted to starch, and corresponding proportion of poly(methyl acrylate) was 41%. The molecular weight distributions of the homopolymer and graft portions were characterized, and extrusion conditions were established for production of ribbon samples of starch-g-PS and starch-g-PMA. Both copolymer types were considerably weakened by soaking in water, and this effect was more immediate and drastic for starch-g-poly(methyl acrylate). Both graft copolymers regained their original tensile strengths on drying, but the poly(methyl acrylate) specimens did not recover their original unswollen dimensions and retained high breaking elongations characteristic of soaked specimens. Tensile and dynamic mechanical properties of extruded and molded samples of both graft polymers are reported, and plasticizing effects of water are summarized

Fish skin bacteria: Colonial and cellular hydrophobicity.

Science.gov (United States)

Sar, N; Rosenberg, E

1987-05-01

Bacteria were desorbed from the skin of healthy, fast-swimming fish by several procedures, including brief exposure to sonic oscillation and treatment with nontoxic surface active agents. The surface properties of these bacteria were studied by measuring their adhesion to hexadecane, as well as by a newly developed, simple method for studying the hydrophobicity of bacterial lawns. This method, referred to as the "Direction of Spreading" (DOS) method, consists of recording the direction to which a water drop spreads when introduced at the border between bacterial lawns and other surfaces. Of the 13 fish skin isolates examined, two strains were as hydrophobic as polystyrene by the DOS method. Suspended cells of one of these strains adhered strongly to hexadecane (84%), whereas cells of the other strain adhered poorly (13%). Another strain which was almost as hydrophobic as polystyrene by the DOS method did not adhere to hexadecane at all. Similarly, lawns of three other strains were more hydrophobic than glass by the DOS method, but cell suspensions prepared from these colonies showed little or no adhesion to hexadecane. The high colonial but relatively low cellular hydrophobicity could be due to a hydrophobic slime that is removed during the suspension and washing procedures. The possibility that specific bacteria assist in fish locomotion by changing the surface properties of the fish skin and by producing drag-reducing polymers is discussed.

Intraocular Pressure in Pregnant and Non-Pregnant Nigerian Women

African Journals Online (AJOL)

Erah

. ... ocular diseases and these were used as the exclusion ... between groups with student's t-test. ... SD = standard deviation, SEM = standard error of mean, N= .... 38(4):229-34. 26. Qureshi IA. Intraocular pressure and pregnancy. Clin. Med.

Systems genetics identifies a role for Cacna2d1 regulation in elevated intraocular pressure and glaucoma susceptibility

OpenAIRE

Chintalapudi, Sumana R.; Maria, Doaa; Di Wang, Xiang; Bailey, Jessica N. Cooke; Hysi, Pirro G.; Wiggs, Janey L.; Williams, Robert W.; Jablonski, Monica M.

2017-01-01

textabstractGlaucoma is a multi-factorial blinding disease in which genetic factors play an important role. Elevated intraocular pressure is a highly heritable risk factor for primary open angle glaucoma and currently the only target for glaucoma therapy. Our study helps to better understand underlying genetic and molecular mechanisms that regulate intraocular pressure, and identifies a new candidate gene, Cacna2d1, that modulates intraocular pressure and a promising therapeutic, pregabalin, ...

Cambios de la presión intraocular en pacientes con hipertensión arterial

Directory of Open Access Journals (Sweden)

G. Tenorio-Guajardo

2014-07-01

Conclusiones: En este estudio se encontró correlación entre presión intraocular y la presión arterial diastólica, pero no se encontró correlación entre la sistólica. Es recomendable vigilar la presión intraocular en pacientes hipertensos, especialmente en aquellos con hipertensión diastólica persistente y con antecedentes familiares de glaucoma.

Photodynamic therapy of intraocular cancers

International Nuclear Information System (INIS)

Gravier, N.; Duvournau, Y.; Querec, M.A.; Pechereau, A.; Patrice, T.

1992-01-01

The most common intraocular tumors are choroidal malignant melanomas (70%) and retinoblastomas (13%). Each time that visual acuity is preserved, various conservative treatments are considered relative to the potential risk of metastatic disease during enucleation. In addition to standard techniques, photodynamic therapy is a potentially attractive new approach limited in its effects to the area of the treated tumor. The purpose of this preclinical study is to determine a reference dose-effect for single laser doses and to study effects of fractionation of the laser dose. (author). 9 refs., 1 tab

Computational study of chain transfer to monomer reactions in high-temperature polymerization of alkyl acrylates.

Science.gov (United States)

Moghadam, Nazanin; Liu, Shi; Srinivasan, Sriraj; Grady, Michael C; Soroush, Masoud; Rappe, Andrew M

2013-03-28

This article presents a computational study of chain transfer to monomer (CTM) reactions in self-initiated high-temperature homopolymerization of alkyl acrylates (methyl, ethyl, and n-butyl acrylate). Several mechanisms of CTM are studied. The effects of the length of live polymer chains and the type of monoradical that initiated the live polymer chains on the energy barriers and rate constants of the involved reaction steps are investigated theoretically. All calculations are carried out using density functional theory. Three types of hybrid functionals (B3LYP, X3LYP, and M06-2X) and four basis sets (6-31G(d), 6-31G(d,p), 6-311G(d), and 6-311G(d,p)) are applied to predict the molecular geometries of the reactants, products and transition sates, and energy barriers. Transition state theory is used to estimate rate constants. The results indicate that abstraction of a hydrogen atom (by live polymer chains) from the methyl group in methyl acrylate, the methylene group in ethyl acrylate, and methylene groups in n-butyl acrylate are the most likely mechanisms of CTM. Also, the rate constants of CTM reactions calculated using M06-2X are in good agreement with those estimated from polymer sample measurements using macroscopic mechanistic models. The rate constant values do not change significantly with the length of live polymer chains. Abstraction of a hydrogen atom by a tertiary radical has a higher energy barrier than abstraction by a secondary radical, which agrees with experimental findings. The calculated and experimental NMR spectra of dead polymer chains produced by CTM reactions are comparable. This theoretical/computational study reveals that CTM occurs most likely via hydrogen abstraction by live polymer chains from the methyl group of methyl acrylate and methylene group(s) of ethyl (n-butyl) acrylate.

[Hyperopic Laser-in-situ-Keratomileusis after trifocal intraocular lens implantation : Aberration-free femto-Laser-in-situ-Keratomileusis treatment after implantation of a diffractive, multifocal, toric intraocular lens-case analysis].

Science.gov (United States)

Hemkeppler, E; Böhm, M; Kohnen, T

2018-05-29

A 52-year-old highly myopic female patient was implanted with a multifocal, diffractive, toric intraocular lens because of the wish to be independent of eyeglasses. Despite high-quality, extensive preoperative examinations, a hyperopic refractive error remained postoperatively, which led to the patient's dissatisfaction. This error was treated with Laser-in-situ-Keratomileusis (LASIK). After corneal LASIK treatment and implantation of a diffractive toric multifocal intraocular lens the patient showed a good postoperative visual result without optical phenomena.

Hydrophobicity-induced drying transition in alkanethiol self ...

Indian Academy of Sciences (India)

Raman Research Institute, C.V. Raman Avenue, Bangalore 560 080, India ... Hydrophobicity; hydrophobic gap; self-assembled monolayer; length scale dependent .... From our work, we find that when the alkanethiol SAM is prepared from a.

Visual performance after the implantation of a new trifocal intraocular lens

Directory of Open Access Journals (Sweden)

Vryghem JC

2013-10-01

Full Text Available Jérôme C Vryghem,1,2 Steven Heireman1,21Brussels Eye Doctors, Brussels, Belgium; 2Clinique Saint-Jean, Brussels, BelgiumPurpose: To evaluate the subjective and objective visual results after the implantation of a new trifocal diffractive intraocular lens.Methods: A new trifocal diffractive intraocular lens was designed combining two superimposed diffractive profiles: one with +1.75 diopters (D addition for intermediate vision and the other with +3.50 D addition for near vision. Fifty eyes of 25 patients that were operated on by one surgeon are included in this study. The uncorrected and best distance-corrected monocular and binocular, near, intermediate, and distance visual acuities, contrast sensitivity, and defocus curves were measured 6 months postoperatively. In addition to the standard clinical follow-up, a questionnaire evaluating individual satisfaction and quality of life was submitted to the patients.Results: The mean age of patients at the time of surgery was 70 ± 10 years. The mean uncorrected and corrected monocular distance visual acuity (VA were LogMAR 0.06 ± 0.10 and LogMAR 0.00 ± 0.08, respectively. The outcomes for the binocular uncorrected distance visual acuity were almost the same (LogMAR −0.04 ± 0.09. LogMAR −010 ± 0.15 and 0.02 ± 0.06 were measured for the binocular uncorrected intermediate and near VA, respectively. The distance-corrected visual acuity was maintained in mesopic conditions. The contrast sensitivity was similar to that obtained after implantation of a bifocal intraocular lens and did not decrease in mesopic conditions. The binocular defocus curve confirms good VA even in the intermediate distance range, with a moderate decrease of less than LogMAR 0.2 at −1.5 D, with respect to the best distance VA at 0 D defocus. Patient satisfaction was high. No discrepancy between the objective and subjective outcomes was evidenced.Conclusion: The introduction of a third focus in diffractive multifocal

Method for producing an isoplanatic aspheric monofocal intraocular lens, and resul ting lens

OpenAIRE

Barbero, Sergio; Marcos, Susana; Dorronsoro, Carlos; Montejo, Javier; Salazar Salegui, Pedro

2010-01-01

[EN] The invention can be used to obtain isoplanatic aspheric mono focal intraocular lenses in a viewing range of up to 25° (preferably up to 10°). The method comprises the following steps: l. mathematical defmition of an aphakic eye model; 2. mathematical definition of an intraocular lens model; 3. mathematical defmition of the implantation of the lens; 4. mathematical defmition of the merit function; 5. definition of the contour conditions; 6. defmition of a measurement for charact...

Self-Compacting Concrete Incorporating Micro-SiO2 and Acrylic Polymer

OpenAIRE

Heidari, Ali; Zabihi, Marzieh

2014-01-01

This study examined the effects of using acrylic polymer and micro-SiO2 in self-compacting concrete (SCC). Using these materials in SCC improves the characteristics of the concrete. Self-compacting samples with 1-2% of a polymer and 10% micro-SiO2 were made. In all cases, compressive strength, water absorption, and self-compacting tests were done. The results show that adding acrylic polymer and micro-SiO2 does not have a significant negative effect on the mechanical properties of self-compa...

Intraocular pressure-lowering effect of oral paracetamol and its in vitro corneal penetration properties

Directory of Open Access Journals (Sweden)

Mohamed N

2013-01-01

Full Text Available Nabiel Mohamed, David MeyerDivision of Ophthalmology, Faculty of Medicine and Health Sciences, University of Stellenbosch, Cape Town, South AfricaBackground: Several studies have confirmed the ability of cannabinoids to reduce intraocular pressure. Experimental data recently demonstrated unequivocally that the analgesic effect of paracetamol is due to its indirect action on cannabinoid receptors. The question then arises as to whether paracetamol can reduce intraocular pressure via its effect on intraocular cannabinoid receptors.Methods: A 2-week, prospective, randomized, controlled, single-center, parallel-group pilot study was carried out to determine the efficacy and safety of paracetamol 1 g orally administered every 6 hours in adult patients with primary or secondary open angle glaucoma as compared with topical levobunolol 0.5% twice a day. Patient well-being was closely monitored throughout the study and focused on hepatic safety in accordance with Drug-Induced Liver Injury Network criteria. The in vitro diffusion kinetics of acetaminophen in a phosphate-buffered solution in rabbit and human corneas was also investigated, with the view to a topical application.Results: Eighteen adult patients were enrolled in the study, with nine in the topical levobunolol group and nine in the oral paracetamol group. In the levobunolol group, the mean reduction in intraocular pressure at day 7 was 7.5 mmHg (P < 0.008 and at day 14 was 9.1 mmHg (P < 0.005, from a mean baseline intraocular pressure of 29.6 mmHg. The corresponding figures for the paracetamol group were 8.8 mmHg (P < 0.0004 at day 7 and 6.5 mmHg (P < 0.004 at day 14, from a mean baseline intraocular pressure of 29.4 mmHg. Both study regimens were well tolerated. No serious treatment-related adverse events were reported in either of the treatment groups. Liver function tests, systolic/diastolic blood pressure, or heart rate remained unchanged in both groups during the 2 weeks of the study. In

Bartonella and intraocular inflammation: a series of cases and review of literature

Directory of Open Access Journals (Sweden)

Kalogeropoulos C

2011-06-01

Full Text Available Chris Kalogeropoulos1, Ioannis Koumpoulis1, Andreas Mentis2, Chrisavgi Pappa1, Paraskevas Zafeiropoulos1, Miltiadis Aspiotis11Department of Ophthalmology, Medical School, University of Ioannina, Greece; 2Laboratory of Medical Microbiology, Hellenic Pasteur Institute, Athens, GreecePurpose: To present various forms of uveitis and/or retinal vasculitis attributed to Bartonella infection and review the impact of this microorganism in patients with uveitis.Methods: Retrospective case series study. Review of clinical records of patients diagnosed with Bartonella henselae and Bartonella quintana intraocular inflammation from 2001 to 2010 in the Ocular Inflammation Department of the University Eye Clinic, Ioannina, Greece. Presentation of epidemiological and clinical data concerning Bartonella infection was provided by the international literature.Results: Eight patients with the diagnosis of Bartonella henselae and two patients with B. quintana intraocular inflammation were identified. Since four patients experienced bilateral involvement, the affected eyes totaled 14. The mean age was 36.6 years (range 12–62. Uveitic clinical entities that we found included intermediate uveitis in seven eyes (50%, vitritis in two eyes (14.2%, neuroretinitis in one eye (7.1%, focal retinochoroiditis in one eye (7.1%, branch retinal vein occlusion (BRVO due to vasculitis in one eye (7.1%, disc edema with peripapillary serous retinal detachment in one eye (7.1%, and iridocyclitis in one eye (7.1%. Most of the patients (70% did not experience systemic symptoms preceding the intraocular inflammation. Antimicrobial treatment was efficient in all cases with the exception of the case with neuroretinitis complicated by anterior ischemic optic neuropathy and tubulointerstitial nephritis.Conclusion: Intraocular involvement caused not only by B. henselae but also by B. quintana is being diagnosed with increasing frequency. A high index of suspicion is needed because the

Preparation and Property of Acrylic Acid Rare Earth Complex and Its Hydrosilylation

Institute of Scientific and Technical Information of China (English)

Zhang Ming; Chen Haiyan; Chen Xiaosong; Dai Shaojun; Inoue Shinich; Okamoto Hiroshi

2004-01-01

Acrylic acid rare earth complex was prepared. Its chemical composition was determined by chemical and elemental analysis, and its structure as well as properties was characterized using IR, Fluorescence and UV spectrum, and its solubility was also investigated. Meanwhile a kind of elastic functional polymer with rare earth units in the side chains was produced. It is confirmed by IR spectrum that the Si-H bonds really react with acrylic acid rare earth.

Synthesis of acrylated palm oil nanoparticles using microemulsion polymerization initiated by gamma ray

International Nuclear Information System (INIS)

Rida Tajau; Wan Md Zin Wan Yunus; Khairul Zaman Mohd Dahlan; Mohd Hilmi Mahmood; Kamaruddin Hashim; Sim, Flora; Sharila Muhd Faizal

2010-01-01

The use of microemulsion in the development of nanoparticle based on acrylated palm oil product is demonstrated. The microemulsion polymerization was initiated by gamma ray for synthesizing crosslinked nanoparticle. Polymerization of acrylated palm oil in three-component ionic microemulsions was prepared with sodium dodecyl sulphate (SDS) and water. The resulted nanoparticle, before and after initiated by gamma ray, were evaluated in terms of particle diameter, surface charge and molecular structure. Type and concentration of surfactants, monomer concentration, radiation dose and time of storage strongly affected the size, charge and size stability of the particles. For the development of new microscopic polymer acrylated palm oil can be synthesized into nano sized particle and it has potential to be developed in medical devices and controlled-drug-release-applications. (author)

Durability and Mechanical Performance of PMMA/Stone Sludge Nanocomposites for Acrylic Solid Surface Applications

Directory of Open Access Journals (Sweden)

Samah EL-Bashir

2017-11-01

Full Text Available Acrylic solid surface sheets were prepared by mixing different kinds of stone sludge fillers (SSF in Poly (methyl methacrylate (PMMA nanocomposites. PMMA nanocomposite syrups were made using free radical polymerization of methylmethacrylate (MMA, then two kinds of nanofillers were added, namely, hydrophilic nanosilica and clay Halloysite nanotubules (HNTs. Acrylic solid surface sheets were manufactured by mixing the syrups with SSFs. The morphology of the produced sheets was studied using optical, and Scanning Electron Microscopy (SEM that revealed the uniform distribution of stone sludge in the polymeric matrix. The study of the physical properties showed promising mechanical performance and durability of PMMA/SSF nanocomposites for acrylic solid surface applications.

The role of sodium-poly(acrylates) with different weight-average molar mass in phosphate-free laundry detergent builder systems

OpenAIRE

Milojević, Vladimir S.; Ilić-Stojanović, Snežana; Nikolić, Ljubiša; Nikolić, Vesna; Stamenković, Jakov; Stojiljković, Dragan

2013-01-01

In this study, the synthesis of sodium-poly(acrylate) was performed by polymerization of acrylic acid in the water solution with three different contents of potassium-persulphate as an initiator. The obtained polymers were characterized by using HPLC and GPC analyses in order to define the purity and average molar mass of poly(acrylic acid). In order to investigate the influence of sodium-poly(acrylate) as a part of carbonate/zeolite detergent builder system, secondary washing characteristics...

Contact-killing of adhering streptococci by a quaternary ammonium compound incorporated in an acrylic resin

NARCIS (Netherlands)

Mei, Li; Ren, Yijin; Loontjens, Ton J. A.; van der Mei, Henny C.; Busscher, Henk J.

2012-01-01

Purpose: Acrylates for bonding of joint prostheses and stainless-steel brackets in orthopedics and orthodontics are prone to bacterial adhesion and biofilm formation, respectively, leading to serious infectious complications. Here we describe the preparation of a contact-killing acrylic resin by

Evaluation of Different Power of Near Addition in Two Different Multifocal Intraocular Lenses

Directory of Open Access Journals (Sweden)

Ugur Unsal

2016-01-01

Full Text Available Purpose. To compare near, intermediate, and distance vision and quality of vision, when refractive rotational multifocal intraocular lenses with 3.0 diopters or diffractive multifocal intraocular lenses with 2.5 diopters near addition are implanted. Methods. 41 eyes of 41 patients in whom rotational +3.0 diopters near addition IOLs were implanted and 30 eyes of 30 patients in whom diffractive +2.5 diopters near addition IOLs were implanted after cataract surgery were reviewed. Uncorrected and corrected distance visual acuity, intermediate visual acuity, near visual acuity, and patient satisfaction were evaluated 6 months later. Results. The corrected and uncorrected distance visual acuity were the same between both groups (p=0.50 and p=0.509, resp.. The uncorrected intermediate and corrected intermediate and near vision acuities were better in the +2.5 near vision added intraocular lens implanted group (p=0.049, p=0.005, and p=0.001, resp. and the uncorrected near vision acuity was better in the +3.0 near vision added intraocular lens implanted group (p=0.001. The patient satisfactions of both groups were similar. Conclusion. The +2.5 diopters near addition could be a better choice in younger patients with more distance and intermediate visual requirements (driving, outdoor activities, whereas the + 3.0 diopters should be considered for patients with more near vision correction (reading.

Systems genetics identifies a role for Cacna2d1 regulation in elevated intraocular pressure and glaucoma susceptibility.

Science.gov (United States)

Chintalapudi, Sumana R; Maria, Doaa; Di Wang, Xiang; Bailey, Jessica N Cooke; Hysi, Pirro G; Wiggs, Janey L; Williams, Robert W; Jablonski, Monica M

2017-11-24

Glaucoma is a multi-factorial blinding disease in which genetic factors play an important role. Elevated intraocular pressure is a highly heritable risk factor for primary open angle glaucoma and currently the only target for glaucoma therapy. Our study helps to better understand underlying genetic and molecular mechanisms that regulate intraocular pressure, and identifies a new candidate gene, Cacna2d1, that modulates intraocular pressure and a promising therapeutic, pregabalin, which binds to CACNA2D1 protein and lowers intraocular pressure significantly. Because our study utilizes a genetically diverse population of mice with known sequence variants, we are able to determine that the intraocular pressure-lowering effect of pregabalin is dependent on the Cacna2d1 haplotype. Using human genome-wide association study (GWAS) data, evidence for association of a CACNA2D1 single-nucleotide polymorphism and primary open angle glaucoma is found. Importantly, these results demonstrate that our systems genetics approach represents an efficient method to identify genetic variation that can guide the selection of therapeutic targets.

Test of a large size acrylic scintillation counter

International Nuclear Information System (INIS)

Bertino, M.; De Zorzi, G.; Zanello, D.

1984-01-01

We have tested the behaviour of an acrylic scintillator measuring the attenuation length and the time resolution of a 7.8 m long counter. On a small sample the photon yield relative to the NE 110 plastic has been measured. (orig.)

A study of patient satisfaction after cataract surgery with implantation of different types of intraocular lenses

Directory of Open Access Journals (Sweden)

Wei Ching-Kuo

2012-10-01

Full Text Available Abstract Background The implementation of capitated payment has driven medical institutions through developing balance billing for medical services. By exploring the patients’ decision-making factors on different self-pay items, a reference for the pricing and sales strategy for the related products can be formed. The major purposes of this study were to analyze the determinants of preoperative selection and postoperative satisfaction with implantation of different types of intraocular lenses in cataract surgery. Methods This cross-sectional study consisted of 127 patients that were 50 years of age and older, and who had phacoemulsification with intraocular lens implantation in both eyes. Data were collected by using a structured questionnaire. The following parameters were measured: access to medical care, attitude towards receiving medical products at one’s own expense, overall patient satisfaction and postoperative visual clarity. Results The results showed that the patient’s gender, educational level and economic status influenced the type of intraocular lens chosen. Patients in the insurance group cared about access to medical care, and patients in the balance billing group cared about product differentiation. ANOVA results showed no statistically significant differences in the overall satisfaction of the patients among the groups with different types of intraocular lenses. Patients that received cataract surgery with implantation of multifocal intraocular lenses had better vision when trying to view smaller objects and when looking at objects under strong light. Conclusions Manufacturers should increase the number of differences between their products, and health care providers can then recommend the appropriate intraocular lens in accordance with the needs or demands of their patients, and also by keeping in mind the financial constraints of their patients.

A study of patient satisfaction after cataract surgery with implantation of different types of intraocular lenses.

Science.gov (United States)

Wei, Ching-Kuo; Wang, Shun-Mu; Lin, Jen-Chieh

2012-10-29

The implementation of capitated payment has driven medical institutions through developing balance billing for medical services. By exploring the patients' decision-making factors on different self-pay items, a reference for the pricing and sales strategy for the related products can be formed. The major purposes of this study were to analyze the determinants of preoperative selection and postoperative satisfaction with implantation of different types of intraocular lenses in cataract surgery. This cross-sectional study consisted of 127 patients that were 50 years of age and older, and who had phacoemulsification with intraocular lens implantation in both eyes. Data were collected by using a structured questionnaire. The following parameters were measured: access to medical care, attitude towards receiving medical products at one's own expense, overall patient satisfaction and postoperative visual clarity. The results showed that the patient's gender, educational level and economic status influenced the type of intraocular lens chosen. Patients in the insurance group cared about access to medical care, and patients in the balance billing group cared about product differentiation. ANOVA results showed no statistically significant differences in the overall satisfaction of the patients among the groups with different types of intraocular lenses. Patients that received cataract surgery with implantation of multifocal intraocular lenses had better vision when trying to view smaller objects and when looking at objects under strong light. Manufacturers should increase the number of differences between their products, and health care providers can then recommend the appropriate intraocular lens in accordance with the needs or demands of their patients, and also by keeping in mind the financial constraints of their patients.

Lente intra-ocular opaca em diplopia intratável: relato de caso Opaque intraocular lens in intractable diplopia: case report

Directory of Open Access Journals (Sweden)

Fernanda Teixeira Krieger

2006-08-01

Full Text Available Diplopia intratável tem sido descrita em várias situações. Métodos convencionais como prismas e correção cirúrgica do estrabismo falham em neutralizá-la. O objetivo do trabalho é documentar o caso de uma paciente com estrabismo de longa data, cuja diplopia deteriorou-se ao longo dos anos, e não foi possível resolução com cirurgia, prisma, e oclusão com óculos e lente de contato com pupila opaca. A paciente foi então submetida à facoemulsificação com implante de lente intra-ocular opaca que atingiu o objetivo desejado.Intractable diplopia has been described in many situations but poor results are the rule with standard treatment modalities. The authors report a case of a woman with long-standing strabismus and diplopia who failed to improve following surgery, prism, and occlusive spectacles or contact lenses. Then, she was submitted to phacoemulsification and opaque intraocular lens implantation, which successfully neutralized diplopia.

Soil hydrophobicity: comparative study of usual determination methods

Directory of Open Access Journals (Sweden)

Eduardo Saldanha Vogelmann

2015-02-01

Full Text Available Hydrophobic or water repellent soils slowly absorb water because of the low wett ability of the soil particles which are coated with hydrophobic organic substances. These pose significant effects on plant growth, water infiltration and retention, surface runoff and erosion. The objective of this study was to compare the performance of tension micro-infiltrometer(TMI and the water drop penetration time (WDPT methods in the determination of the hydrophobicity index of eighteen soils from southern Brazil. Soil samples were collected from the 0-5cm soil layer to determine particle size distribution, organic matter content, hydrophobicity index of soil aggregates and droplet penetration time of disaggregated and sieved soil samples. For the TMI method the soil samples were subjected to minor changes due to the use of macroaggregates to preserve the distribution of solid constituents in the soil. Due to the homogeneity of the soil samples the WDPT method gave smaller coefficients of variation unlike the TMI method where the soil structure is preserved. However, both methods had low coefficients of variation, and are thus effective for determining the soil hydrophobicity, especially when the log hydrophobicity index or log WDPT is >1.

Hydrophobic treatment of concrete as protection against chloride penetration

NARCIS (Netherlands)

Vries, J. de; Polder, R.B.; Borsje, H.

1996-01-01

Hydrophobic treatment makes a concrete surface absorb less water and less chloride. Hydrophobic treatment was studied as a protection agninst chloride penetration from deicing salts. Test methods were designed. Nine hydrophobic products were tested, of which three complied to the requirements on

Radiation crosslinking of poly(butyl acrylate) during polymerization and grafted copolymerization with Cr(III) crosslinked collagen

International Nuclear Information System (INIS)

Pietrucha, K.; Kroh, J.

1984-01-01

Enhanced crosslinking of synthetic polymer simultaneous with grafting and homopolymerization processes have been observed in irradiated leather tanned with Cr(III) and embedded with aqueous emulsions of butyl acrylate. Extent of poly(butyl acrylate) crosslinking during copolymerization was found to be approximately one order higher than in the case of radiation polymerization of butyl acrylate in emulsion. New method for isolation of grafted copolymer based on degradation of collagen has been developed. The extent of crosslinking was calculated from the swelling data. (author)

Allergic contact dermatitis caused by nail acrylates in Europe. An EECDRG study

DEFF Research Database (Denmark)

Gonçalo, Margarida; Pinho, André; Agner, Tove

2018-01-01

BACKGROUND: Allergic contact dermatitis (ACD) caused by nail acrylates, also including methacrylates and cyanoacrylates here, is being increasingly reported. METHODS: A retrospective study in 11 European Environmental Contact Dermatitis Research Group (EECDRG) clinics collected information on cases......-hydroxypropyl methacrylate (88.6%), ethylene glycol dimethacrylate (69.2%), and ethyl cyanoacrylate (9.9%). CONCLUSIONS: Nail cosmetics were responsible for the majority of ACD cases caused by acrylates, affecting nail beauticians and consumers, and therefore calling for stricter regulation and preventive...

In vivo chromatic aberration in eyes implanted with intraocular lenses.

Science.gov (United States)

Pérez-Merino, Pablo; Dorronsoro, Carlos; Llorente, Lourdes; Durán, Sonia; Jiménez-Alfaro, Ignacio; Marcos, Susana

2013-04-12

To measure in vivo and objectively the monochromatic aberrations at different wavelengths, and the chromatic difference of focus between green and infrared wavelengths in eyes implanted with two models of intraocular lenses (IOL). EIGHTEEN EYES PARTICIPATED IN THIS STUDY: nine implanted with Tecnis ZB99 1-Piece acrylic IOL and nine implanted with AcrySof SN60WF IOL. A custom-developed laser ray tracing (LRT) aberrometer was used to measure the optical aberrations, at 532 nm and 785 nm wavelengths. The monochromatic wave aberrations were described using a fifth-order Zernike polynomial expansion. The chromatic difference of focus was estimated as the difference between the equivalent spherical errors corresponding to each wavelength. Wave aberration measurements were highly reproducible. Except for the defocus term, no significant differences in high order aberrations (HOA) were found between wavelengths. The average chromatic difference of focus was 0.46 ± 0.15 diopters (D) in the Tecnis group, and 0.75 ± 0.12 D in the AcrySof group, and the difference was statistically significant (P Chromatic difference of focus in the AcrySof group was not statistically significantly different from the Longitudinal chromatic aberration (LCA) previously reported in a phakic population (0.78 ± 0.16 D). The impact of LCA on retinal image quality (measured in terms of Strehl ratio) was drastically reduced when considering HOA and astigmatism in comparison with a diffraction-limited eye, yielding the differences in retinal image quality between Tecnis and AcrySof IOLs not significant. LRT aberrometry at different wavelengths is a reproducible technique to evaluate the chromatic difference of focus objectively in eyes implanted with IOLs. Replacement of the crystalline lens by the IOL did not increase chromatic difference of focus above that of phakic eyes in any of the groups. The AcrySof group showed chromatic difference of focus values very similar to physiological values in

Experimental differentiation of intraocular masses using ultrahigh-field magnetic resonance imaging--a case series.

Directory of Open Access Journals (Sweden)

Karen Falke

Full Text Available PURPOSE: The case reports presented here were compiled to demonstrate the potential for improved diagnosis and monitoring of disease progress of intraocular lesions using ultrahigh-field magnetic resonance microscopy (MRM at 7.1 Tesla. METHODS: High-resolution ex vivo ocular magnetic resonance (MR images were acquired on an ultrahigh-field MR system (7.1 Tesla, ClinScan, Bruker BioScan, Germany using a 2-channel coil with 4 coil elements and T2-weighted turbo spin echo (TSE sequences of human eyes enucleated because of different intraocular lesions. Imaging parameters were: 40×40 mm field of view, 512×512 matrix, and 700 µm slice thickness. The results were correlated with in vivo ultrasound and histology of the enucleated eyes. RESULTS: Imaging was performed in enucleated eyes with choroidal melanoma, malignant melanoma of iris and ciliary body with scleral perforation, ciliary body melanoma, intraocular metastasis of esophageal cancer, subretinal bleeding in the presence of perforated corneal ulcer, hemorrhagic choroidal detachment, and premature retinopathy with phthisis and ossification of bulbar structures. MR imaging allowed differentiation between solid and cystic tumor components. In case of hemorrhage, fluid-fluid levels were identified. Melanin and calcifications caused significant hypointensity. Microstructural features of eye lesions identified by MRM were confirmed by histology. CONCLUSION: This study demonstrates the potential of MRM for the visualization and differential diagnosis of intraocular lesions. At present, the narrow bore of the magnet still limits the use of this technology in humans in vivo. Further advances in ultrahigh-field MR imaging will permit visualization of tumor extent and evaluation of nonclassified intraocular structures in the near future.

Quantitative Assessment of the Impact of Blood Pulsation on Intraocular Pressure Measurement Results in Healthy Subjects

Directory of Open Access Journals (Sweden)

Robert Koprowski

2017-01-01

Full Text Available Background. Blood pulsation affects the results obtained using various medical devices in many different ways. Method. The paper proves the effect of blood pulsation on intraocular pressure measurements. Six measurements for each of the 10 healthy subjects were performed in various phases of blood pulsation. A total of 8400 corneal deformation images were recorded. The results of intraocular pressure measurements were related to the results of heartbeat phases measured with a pulse oximeter placed on the index finger of the subject’s left hand. Results. The correlation between the heartbeat phase measured with a pulse oximeter and intraocular pressure is 0.69±0.26 (p<0.05. The phase shift calculated for the maximum correlation is equal to 60±40° (p<0.05. When the moment of measuring intraocular pressure with an air-puff tonometer is not synchronized, the changes in IOP for the analysed group of subjects can vary in the range of ±2.31 mmHg (p<0.3. Conclusions. Blood pulsation has a statistically significant effect on the results of intraocular pressure measurement. For this reason, in modern ophthalmic devices, the measurement should be synchronized with the heartbeat phases. The paper proposes an additional method for synchronizing the time of pressure measurement with the blood pulsation phase.

Cerebral migration of intraocular silicone oil: an MRI study

DEFF Research Database (Denmark)

Kiilgaard, Jens Folke; Milea, Dan; Løgager, Vibeke

2011-01-01

for retinal detachment. Methods: Nineteen patients included in this study were referred for silicone oil removal after uncomplicated retinal detachment surgery using internal silicone oil tamponade. Patients with a previous history of intraocular silicone oil, glaucoma or optic pit were excluded. After...

Extraction Equilibrium of Acrylic Acid by Aqueous Two-Phase Systems Using Hydrophilic Ionic Liquids

International Nuclear Information System (INIS)

Lee, Yong Hwa; Lee, Woo Youn; Kim, Ki-Sub; Hong, Yeon Ki

2014-01-01

As an effective method for extraction of acrylic acid, aqueous two-phase systems based on morpholinium ionic liquids were used in this study. Effects of the alkyl chain length of cation in morpholinium ionic liquids on phase diagram and extraction efficiencies were investigated. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of morpholinium ionic liquids to aqueous K 2 HPO 4 solutions. It can be found that the ability of morpholinium ionic liquids for phase separation followed the order [HMMor][Br]>[OMMor][Br]>[BMMor][Br]>[EMMor][Br]. There was little difference between binodal curves of imidazolium ionic liquids and those of morpholinium ionic liquids. 50-90% of the extraction efficiency was observed for acrylic acid by aqueous two phase extraction of acrylic acid with morpholinium ionic liquids. It can be concluded that morpholinium ionic liquids/K 2 HPO 4 were effective for aqueous two phases extraction of acrylic acid comparing to imidazolium ionic liquids/K 2 HPO 4 systems because of their lower cost

Comparison of intraocular pressure measurement between rebound, non-contact and Goldmann applanation tonometry in treated glaucoma patients.

Science.gov (United States)

Vincent, Stephen J; Vincent, Roslyn A; Shields, David; Lee, Graham A

2012-01-01

To compare the intraocular pressure readings obtained with the iCare rebound tonometer and the 7CR non-contact tonometer with those measured by Goldmann applanation tonometry in treated glaucoma patients. A prospective, cross-sectional study was conducted in a private tertiary glaucoma clinic. One hundred nine (54 males : 55 females) patients including only eyes under medical treatment for glaucoma. Measurement by Goldmann applanation tonometry, iCare rebound tonometry and 7CR non-contact tonometry. Intraocular pressure. There were strong correlations between the intraocular pressure measurements obtained with Goldmann and both the rebound and non-contact tonometers (Spearman r-values ≥ 0.79, P tonometer. For the rebound tonometer, the mean intraocular pressure was slightly higher compared with the Goldmann applanation tonometer in the right eyes (P = 0.02), and similar in the left eyes (P = 0.93); however, these differences did not reach statistical significance. The Goldmann correlated measurements from the non-contact tonometer were lower than the average Goldmann reading for both right (P 0.01) eyes. The corneal compensated measurements from the non-contact tonometer were significantly higher compared with the other tonometers (P ≤ 0.001). The iCare rebound tonometer and the 7CR non-contact tonometer measure intraocular pressure in fundamentally different ways to the Goldmann applanation tonometer. The resulting intraocular pressure values vary between the instruments and will need to be considered when comparing clinical versus home acquired measurements. © 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists.

A study of Brachytherapy for Intraocular Tumor

International Nuclear Information System (INIS)

Ji, Kwang Soo; Yoo, Dae Hyun; Lee, Sung Goo; Kim, Jae Hu; Ji, Young Hun

1996-01-01

The eye enucleation or external-beam radiation therapy that has been commonly used for the treatment of intraocular tumor have demerits of visual loss and in deficiency of effective tumor dose. Recently, brachytherapy using the plaques containing radioisotope-now treatment method that decrease the demerits of the above mentioned treatment methods and increase the treatment effect-is introduced and performed in the countries, Our purpose of this research is to design suitable shape of plaque for the ophthalmic brachytherapy, and to measure absorbed doses of Ir-192 ophthalmic plaque and thereby calculate the exact radiation dose of tumor and it's adjacent normal tissue. In order to brachytherapy for intraocular tumor, 1. to determine the eye model and selected suitable radioisotope 2. to design the suitable shape of plaque 3. to measure transmission factor and dose distribution for custom made plaques 4. to compare with the these data and results of computer dose calculation models. The result were as followed. 1. Eye model was determined as a 25 mm diameter sphere, Ir-192 was considered the most appropriate as radioisotope for brachytherapy, because of the size, half, energy and availability. 2. Considering the biological response with human tissue and protection of exposed dose, we made the plaques with gold, of which size were 15 mm, 17 mm and 20 mm in diameter, and 1.5 mm in thickness. 3. Transmission factor of plaques are all 0.71 with TLD and film dosimetry at the surface of plaques and 0.45, 0.49 at 1.5 mm distance of surface, respectively. 4. As compared the measured data for the plaque with Ir-192 seeds to results of computer dose calculation model by Gary Luxton et al. and CAP-PLAN (Radiation Treatment Planning System), absorbed doses are within ±10% and distance deviations are within 0.4 mm Maximum error is -11.3% and 0.8 mm, respectively. As a result of it, we can treat the intraocular tumor more effectively by using custom made gold plaque and Ir-192

[Contemporary possibilities of intraocular pressure measurement].

Science.gov (United States)

Hornová, J; Baxant, A

2013-10-01

Authors introduced current possibilities of measuring intraocular pressure (IOP). A list of available methods of monitoring IOP is published; contact measurement method IOP directly on the cornea, but also over upper lid, methodology of minimal contact and non-contact measurement. Following contact methods are described; former measurements of IOP by impression Schiotz tonometer and the current methodology applanation. So far as the gold standard measurement Goldmann applanation tonometer (GAT) is considered, another methodology with applanation measurements are compared: Pascal dynamic contoured tonometer (DCT ), BioResonator - resonant applanation tonometer (ART ), digital applanation tonometer Tonopen and last hit: continuous measurement of IOP by Sensimed Triggerfish. Orientation and rapid assessment is palpation pressure control over the lid and measuring by tonometer Diaton. Rebound tonometer (RBT) iCare belongs to measurements with minimal contact, no need anesthetic drops and fluorescein, therefore a self - home version of IOP measurements (Icare ONE) is developed. Non-contact measurement of IOP by different pneumotonometers is popular for screening assessment of IOP. Reichert Ocular Response Analyzer (ORA) is a non-contact applanation IOP measurement and reveals additional properties of the cornea. In the discussion of a range methodology is evaluated, the experience of other authors and their own experience is compared. For monitoring of patients is necessary to select the most suitable methodology, measure repeatedly and accurately to allow long-term monitoring of intraocular pressure.

Apparatus and method for non-contact, acoustic resonance determination of intraocular pressure

Science.gov (United States)

Sinha, D.N.; Wray, W.O.

1994-12-27

The apparatus and method for measuring intraocular pressure changes in an eye under investigation by detection of vibrational resonances therein. An ultrasonic transducer operating at its resonant frequency is amplitude modulated and swept over a range of audio frequencies in which human eyes will resonate. The output therefrom is focused onto the eye under investigation, and the resonant vibrations of the eye observed using a fiber-optic reflection vibration sensor. Since the resonant frequency of the eye is dependent on the pressure therein, changes in intraocular pressure may readily be determined after a baseline pressure is established. 3 figures.

Design of textured surfaces for super-hydrophobicity

Indian Academy of Sciences (India)

Prithvi Raj Jelia

2017-11-11

Nov 11, 2017 ... as silicon wafer [1, 10, 11]. Yoon et al [12] used a modified ... The explanation for the increase in the contact angle or hydrophobicity on the ... water droplets on super-hydrophobic surfaces that exhibit large contact angles are ...

Preparation of hydrophobic Pt-catalysts for decontamination of nuclear effluents

International Nuclear Information System (INIS)

Ionita, Gh.; Popescu, I.; Retegan, T.; Stefanescu, I.

2005-01-01

Based on the long experience of the authors, in the preparation, testing and evaluation of the performances of hydrophobic catalysts, and based on the reviewed references, this paper presents up-to-date R and D activities on the preparation methods and applications of the hydrophobic catalysts, in deuterium and tritium separation. The objectives of the paper are: (1) to provide a database for selection of the most appropriate catalyst and catalytic packing for above mentioned processes, (2) to evaluate the potentiality of hydrophobic Pt-catalysts in the deuterium and tritium separation (3) to asses and to find a new procedure for preparation a new improved hydrophobic catalyst. The merits of the hydrophobic catalysts are shown in comparison to hydrophilic catalysts. As results of the review some general conclusions about the applications of hydrophobic catalysts in environmental field are as follow: (1) the hydrophobic Pt-catalysts packed in the trickle bed reactors showed a high catalytic activity and long stability; (2) the utilization of the hydrophobic Pt-catalysts for tritium removal from liquid and gaseous effluent in nuclear field was entirely confirmed on industrial scale; (3) the extension of the utilization of the hydrophobic Pt-catalysts in other new processes, which take place in presence of liquid water or high humidity are subjected to testing. (author)

Preparation of hydrophobic Pt-catalysts for decontamination of nuclear effluents

International Nuclear Information System (INIS)

Ionita, Gh.; Popescu, I.; Retegan, T.; Stefanescu, I.

2004-01-01

Based on the long experience of the authors, in the preparation, testing and evaluation of the performances of hydrophobic catalysts, and based on the reviewed references, this paper presents up-to-date R and D activities on the preparation methods and applications of the hydrophobic catalysts, in deuterium and tritium separation. The objectives of the paper are: - to provide a database for selection of the most appropriate catalyst and catalytic packing for above mentioned processes; - to evaluate the potentiality of hydrophobic Pt-catalysts in the deuterium and tritium separation; - to assess and to find a new procedure for preparation a new improved hydrophobic catalyst. The merits of the hydrophobic catalysts are shown in comparison to hydrophilic catalysts. As results of the review some general conclusions about the applications of hydrophobic catalysts in environmental field are as follows: - the hydrophobic Pt-catalysts packed in the trickle bed reactors showed a high catalytic activity and long stability; - the utilization of the hydrophobic Pt-catalysts for tritium removal from liquid and gaseous effluent in nuclear field was entirely confirmed on industrial scale; - the extension of the utilization of the hydrophobic Pt-catalysts in other new processes, which take place in presence of liquid water or high humidity are subject to testing. (authors)

The protection of different Italian marbles with two partially flourinated acrylic copolymers

Science.gov (United States)

Poli, T.; Toniolo, L.; Chiantore, O.

Committing stone protection to polymeric materials started in the sixties but the study and knowledge of the complex and multiple interactions between stone and polymers has only been carried out recently. It's important to note that, together with the factors related to the polymeric system itself, intrinsic properties of the stone substrate, like composition, porosity, and crystalline characteristics, play a relevant role. In this paper the issues related to protection of three different Italian marbles have been investigated: Candoglia marble, employed in the building of the Milan Cathedral, Carrara marble, widely used in sculpture and historical architecture, and S. Giuliano marble, used in the building of the Pisa Cathedral and its famous leaning tower. Specimens coming from blocks of the three quarried stones have been characterized, treated with two new partially fluorinated acrylic copolymers, 2,2,2-trifluoroethyl methacrylate/methyl acrylate (TFEMA/MA), and trifluoromethyl-2,2,2-trifluorethyl methacrylate/methyl acrylate (HFIMA/MA), and tested according to UNI-Normal Italian protocol. All the measurements including capillary water absorption, static contact angles, colour variation, water vapour permeability, and SEM morphological analysis have been carried out before and after the polymeric treatment. The aim of this work is to evaluate the protective efficacy of these two new partially fluorinated acrylic copolymers on the three different marbles, and to correlate the different behaviours with the polymers' properties and with the stone substrates characteristics.

Preparation and characterization of poly(acrylic acid)-hydroxyethyl cellulose graft copolymer.

Science.gov (United States)

Abdel-Halim, E S

2012-10-01

Poly(acrylic acid) hydroxyethyl cellulose [poly(AA)-HEC] graft copolymer was prepared by polymerizing acrylic acid (AA) with hydroxyethyl cellulose (HEC) using potassium bromate/thiourea dioxide (KBrO(3)/TUD) as redox initiation system. The polymerization reaction was carried out under a variety of conditions including concentrations of AA, KBrO(3) and TUD, material to liquor ratio and polymerization temperature. The polymerization reaction was monitored by withdrawing samples from the reaction medium and measuring the total conversion. The rheological properties of the poly(AA)-HEC graft copolymer were investigated. The total conversion and rheological properties of the graft copolymer depended on the ratio of KBrO(3) to TUD and on acrylic acid concentration as well as temperature and material to liquor ratio. Optimum conditions of the graft copolymer preparation were 30 mmol KBrO(3) and 30 mmol TUD/100g HEC, 100% AA (based on weight of HEC), duration 2h at temperature 50 °C using a material to liquor ratio of 1:10. Copyright © 2012. Published by Elsevier Ltd.

Microstructural aspects in steel fiber reinforced acrylic emulsion polymer modified concrete

Science.gov (United States)

Hazimmah, Dayang; Ayob, Afizah; Sie Yee, Lau; Chee Cung, Wong

2018-03-01

Scanning electron microscope observations of polymer-free and polymer-modified cements have shown that the polymer particles are partitioned between the inside of hydrates and the surface of anhydrous cement grains. For optimum dosage of acrylic emulsion polymer with 2.5%, the C-S-H gel in this structure is finer and more acicular. Some polymer adheres or deposit on the surface of the C-S-H gel. The presence of acrylic emulsion polymer confines the ionic diffusion so that the Ca(OH)2 crystallized locally to form fine crystals. The void in the structures seems to be smaller but no polymer films appears to be bridging the walls of pores although many polymer bonds or C-S-H spread into the pore spaces. In addition to porosity reduction, acrylic emulsion polymer modified the hydration products in the steel fiber -matrix ITZ. The hydration product C-S-H appeared as a needle like shape. The needle-shaped C-S-H increases and gradually formed the gel, with needles growing into the pore space. The phenomenon is more obvious as curing age increased.

Radiation crosslinking of poly(butyl acrylate) during polymerization and grafted copolymerization with Cr(III) crosslinked collagen

International Nuclear Information System (INIS)

Pietrucha, K.; Kroh, J.

1986-01-01

Enhanced crosslinking of synthetic polymer simultaneously with grafting and homopolymerization processes has been observed in irradiated leather tanned with Cr(III) and embedded with aqueous emulsions of butyl acrylate. The extent of poly(butyl acrylate) crosslinking during copolymerization was found to be approximately one order higher than in the case of radiation polymerization of butyl acrylate in emulsion. A new method for isolation of grafted copolymer based on degradation of collagen has been developed. The extent of crosslinking was calculated from the swelling data. (author)

Characterisation of UV-cured acrylate networks by means of hydrolysis followed by aqueous size-exclusion combined with reversed-phase chromatography

NARCIS (Netherlands)

Peters, R.; Litvinov, V. M.; Steeman, P.; Dias, A. A.; Mengerink, Y.; van Benthem, R.; de Koster, C. G.; van der Wal, S. J.; Schoenmakers, P.

2007-01-01

UV-cured networks prepared from mixtures of di-functional (polyethylene-glycol di-acrylate) and mono-functional (2-ethylhexyl acrylate) acrylates were analysed after hydrolysis, by aqueous size-exclusion chromatography coupled to on-line reversed-phase liquid-chromatography. The mean network density

A STUDY OF CASE SERIES OF INTRAOCULAR FOREIGN BODIES IN A TERTIARY CARE CENTER IN SOUTH INDIA

Directory of Open Access Journals (Sweden)

Shilpa Y. D

2017-09-01

Full Text Available BACKGROUND Intraocular foreign bodies can cause vision threatening complication in cases of penetrating ocular injuries. Ocular injuries can occur anywhere at work place, at home, due to road traffic accidents, etc. Accidental eye injuries are common in males in work place. Awareness about using protective eye wear is required at work places where injuries are common. The aim of the study is to study the demographic profile, visual and anatomical outcome in patients presenting with posterior segment Intraocular Foreign Bodies (IOFB undergoing vitrectomy. MATERIALS AND METHODS Retrospective analysis was done on patients who underwent pars plana vitrectomy for posterior segment IOFB from March 2014 to April 2017. Complete ocular examination, B scan ultrasonography and x-ray orbit were done in all cases and retained posterior segment intraocular foreign body confirmed. Intraoperative difficulties, anatomical and visual outcome and postoperative complications were studied. RESULTS Cases with posterior segment intraocular foreign body and endophthalmitis had poor visual and anatomical outcome. Patients who underwent complete vitrectomy with 240 encirclage band with or without tamponade had better visual outcome. CONCLUSION Imaging in the injured eye is important to identify the presence of intraocular foreign body. Planning of the surgical procedure depending on the ocular condition plays a vital role in visual outcome.

Structuring unbreakable hydrophobic barriers in paper

Science.gov (United States)

Nargang, Tobias M.; Kotz, Frederik; Rapp, Bastian E.

2018-02-01

Hydrophobic barriers are one of the key elements of microfluidic paper based analytical devices (μPADs).μPADs are simple and cost efficient and they can be carried out without the need of high standard laboratories. To carry out such a test a method is needed to create stable hydrophobic barriers. Commonly used methods like printing wax or polystyrene have the major drawback that these barriers are stiff and break if bended which means they will no longer be able to retain a liquid sample. Here we present silanes to structure hydrophobic barriers via polycondensation and show a silanization method which combines the advantages of flexible silane/siloxane layers with the short processing times of UV-light based structuring. The barriers are created by using methoxy silanes which are mixed with a photo acid generator (PAG) as photoinitiator. Also a photosensitizer was given to the mixture to increase the effectiveness of the PAG. After the PAG is activated by UV-light the silane is hydrolyzed and coupled to the cellulose via polycondensation. The created hydrophobic barriers are highly stable and do not break if being bended.

Foldable micro coils for a transponder system measuring intraocular pressure

Energy Technology Data Exchange (ETDEWEB)

Ullerich, S.; Schnakenberg, U. [Technische Hochschule Aachen (Germany). Inst. of Materials in Electrical Engineering 1; Mokwa, W. [Technische Hochschule Aachen (Germany). Inst. of Materials in Electrical Engineering 1]|[Fraunhofer Inst. of Microelectronic Circuits and Systems, Duisburg (Germany); Boegel, G. vom [Fraunhofer Inst. of Microelectronic Circuits and Systems, Duisburg (Germany)

2001-07-01

A foldable transponder system consisting of a chip and a micro coil for measuring intraocular pressure continuously is presented. The system will be integrated in the haptic of a soft artificial intraocular lens. Calculations of planar micro coils with 6 mm and 10.3 mm in diameter show the limits for planar coils with an outer diameter of 6 mm. For the realisation of the transponder system a 20 {mu}m thick coil with an outer diameter of 10.3 mm, an inner diameter of 7.7 mm, 16 turns and a gap of 20 {mu}m between the windings was selected. Measurements show a good agreement between calculated and measured values. Wireless pressure measurements were carried out showing a linear behaviour of the output signal with respect to the applied pressure. (orig.)

Bacterial contamination of intraocular lens surgery.

OpenAIRE

Vafidis, G C; Marsh, R J; Stacey, A R

1984-01-01

One hundred sterile intraocular lenses were placed on the external eye of 50 patients during cataract surgery. Half of the specimens were cultured for bacteria, the other half were examined under the light microscope after fixing and staining. A bacterial contamination rate of 26% was recorded. This is significantly higher than that found in conjunctival swabs (6%) or irrigation specimens (8%) taken at the same time, and higher than that recorded in a group of control lenses (15.2%) exposed t...

Atom transfer radical polymerization of n-butyl acrylate catalyzed by atom transfer radical polymerization of n-butyl acrylate catalyzed by

NARCIS (Netherlands)

Zhang, H.; Linde, van der R.

2002-01-01

The homogeneous atom transfer radical polymerization (ATRP) of n-butyl acrylate with CuBr/N-(n-hexyl)-2-pyridylmethanimine as a catalyst and ethyl 2-bromoisobutyrate as an initiator was investigated. The kinetic plots of ln([M]0/[M]) versus the reaction time for the ATRP systems in different

Continuous emulsion copolymerisation of styrene and methyl acrylate

NARCIS (Netherlands)

Boomen, van den F.H.A.M.; Meuldijk, J.; Thoenes, D.

1996-01-01

For emulsion polymerisation the reactor type has a strong influence on the final product properties, for example the particle size (distribution) and the polymer composition. A batch copolymerisation of styrene and methyl acrylate shows strong composition drift. The course of the batch reaction has

Pathways to dewetting in hydrophobic confinement.

Science.gov (United States)

Remsing, Richard C; Xi, Erte; Vembanur, Srivathsan; Sharma, Sumit; Debenedetti, Pablo G; Garde, Shekhar; Patel, Amish J

2015-07-07

Liquid water can become metastable with respect to its vapor in hydrophobic confinement. The resulting dewetting transitions are often impeded by large kinetic barriers. According to macroscopic theory, such barriers arise from the free energy required to nucleate a critical vapor tube that spans the region between two hydrophobic surfaces--tubes with smaller radii collapse, whereas larger ones grow to dry the entire confined region. Using extensive molecular simulations of water between two nanoscopic hydrophobic surfaces, in conjunction with advanced sampling techniques, here we show that for intersurface separations that thermodynamically favor dewetting, the barrier to dewetting does not correspond to the formation of a (classical) critical vapor tube. Instead, it corresponds to an abrupt transition from an isolated cavity adjacent to one of the confining surfaces to a gap-spanning vapor tube that is already larger than the critical vapor tube anticipated by macroscopic theory. Correspondingly, the barrier to dewetting is also smaller than the classical expectation. We show that the peculiar nature of water density fluctuations adjacent to extended hydrophobic surfaces--namely, the enhanced likelihood of observing low-density fluctuations relative to Gaussian statistics--facilitates this nonclassical behavior. By stabilizing isolated cavities relative to vapor tubes, enhanced water density fluctuations thus stabilize novel pathways, which circumvent the classical barriers and offer diminished resistance to dewetting. Our results thus suggest a key role for fluctuations in speeding up the kinetics of numerous phenomena ranging from Cassie-Wenzel transitions on superhydrophobic surfaces, to hydrophobically driven biomolecular folding and assembly.

Clinical and optical intraocular performance of rotationally asymmetric multifocal IOL plate-haptic design versus C-loop haptic design.

Science.gov (United States)

Alió, Jorge L; Plaza-Puche, Ana B; Javaloy, Jaime; Ayala, María José; Vega-Estrada, Alfredo

2013-04-01

To compare the visual and intraocular optical quality outcomes with different designs of the refractive rotationally asymmetric multifocal intraocular lens (MFIOL) (Lentis Mplus; Oculentis GmbH, Berlin, Germany) with or without capsular tension ring (CTR) implantation. One hundred thirty-five consecutive eyes of 78 patients with cataract (ages 36 to 82 years) were divided into three groups: 43 eyes implanted with the C-Loop haptic design without CTR (C-Loop haptic only group); 47 eyes implanted with the C-Loop haptic design with CTR (C-Loop haptic with CTR group); and 45 eyes implanted with the plate-haptic design (plate-haptic group). Visual acuity, contrast sensitivity, defocus curve, and ocular and intraocular optical quality were evaluated at 3 months postoperatively. Significant differences in the postoperative sphere were found (P = .01), with a more myopic postoperative refraction for the C-Loop haptic only group. No significant differences were detected in photopic and scotopic contrast sensitivity among groups (P ⩾ .05). Significantly better visual acuities were present in the C-Loop haptic with CTR group for the defocus levels of -2.0, -1.5, -1.0, and -0.50 D (P ⩽.03). Statistically significant differences among groups were found in total intraocular root mean square (RMS), high-order intraocular RMS, and intraocular coma-like RMS aberrations (P ⩽.04), with lower values from the plate-haptic group. The plate-haptic design and the C-Loop haptic design with CTR implantation both allow good visual rehabilitation. However, better refractive predictability and intraocular optical quality was obtained with the plate-haptic design without CTR implantation. The plate-haptic design seems to be a better design to support rotational asymmetric MFIOL optics. Copyright 2013, SLACK Incorporated.

Cast Partial Denture versus Acrylic Partial Denture for Replacement of Missing Teeth in Partially Edentulous Patients

Directory of Open Access Journals (Sweden)

Pramita Suwal

2017-03-01

Full Text Available Aim: To compare the effects of cast partial denture with conventional all acrylic denture in respect to retention, stability, masticatory efficiency, comfort and periodontal health of abutments. Methods: 50 adult partially edentulous patient seeking for replacement of missing teeth having Kennedy class I and II arches with or without modification areas were selected for the study. Group-A was treated with cast partial denture and Group-B with acrylic partial denture. Data collected during follow-up visit of 3 months, 6 months, and 1 year by evaluating retention, stability, masticatory efficiency, comfort, periodontal health of abutment. Results: Chi-square test was applied to find out differences between the groups at 95% confidence interval where p = 0.05. One year comparison shows that cast partial denture maintained retention and stability better than acrylic partial denture (p< 0.05. The masticatory efficiency was significantly compromising from 3rd month to 1 year in all acrylic partial denture groups (p< 0.05. The comfort of patient with cast partial denture was maintained better during the observation period (p< 0.05. Periodontal health of abutment was gradually deteriorated in all acrylic denture group (p

Radiation-curing of acrylate composites including carbon fibres: A customized surface modification for improving mechanical performances

International Nuclear Information System (INIS)

Martin, Arnaud; Pietras-Ozga, Dorota; Ponsaud, Philippe; Kowandy, Christelle; Barczak, Mariusz; Defoort, Brigitte; Coqueret, Xavier

2014-01-01

The lower transverse mechanical properties of radiation-cured acrylate-based composites reinforced with carbon-fibre with respect to the thermosettable analogues was investigated from the viewpoint of chemical interactions at the interface between the matrix and the carbon material. XPS analysis of representative commercial carbon fibres revealed the presence of a significant amount of chemical functions potentially exerting an adverse effect on the initiation and propagation of the free radical polymerization initiated under high energy radiation. The EB-induced polymerization of n-butyl acrylate as a simple model monomer was conducted in the presence of various aromatic additives exhibiting a strong inhibiting effect, whereas thiols efficiently sensitize the initiation mechanism and undergo transfer reactions. A method based on the surface modification of sized fibres by thiomalic acid is proposed for overcoming the localized inhibition phenomenon and for improving the mechanical properties of the resulting acrylate-based composites. - Highlights: • Surface functions of C-fibres are analyzed for their effect on radical reaction. • Irradiation of nBu-acrylate in presence of aromatic additives reveals inhibition. • Thiol groups sensitize the radiation-initiated polymerization of nBu-acrylate. • Modification of C-fibres with thiomalic acid enhances composite properties

Comparative study of intraocular pressure (IP in Bangladeshi individuals by contact and non contact technique

Directory of Open Access Journals (Sweden)

Sayed Abdul Wadud

2016-07-01

Full Text Available Background: Intraocular pressure (IOP is one of the most important parameters in the diagnosis and treatment of glaucoma. Glaucoma has been established as the second leading cause of blindness. The treatment of glaucoma focuses mainly on lowering intraocular pressure (IOP. The target IOP is often set to a level 20% to 30% of IOP reduction, and consequent large IOP reduction beyond 30% or even 40% in cases of advanced glaucoma The different methods of tonometery are: Goldman Applanation tonometery, Noncontact (air-puff tonometery, Perkins tonometery, Tonopen tonometery, Transpalpebral tonometery.Objective: To determine the frequency of accuracy of intraocular pressure (IOP measured by non-contact (air puff tonometer compared with Goldmann applanation tonometer.Methods: This was a non-interventional, cross sectional study conducted at a tertiary care centre of Dhaka, Bangladesh. consecutive subjects attending the BSMMU eye OPD were included in the study. IOP was measured by non-contact (air puff tonometer and a slit lamp mounted GAT in all the subjects. The study samples were selected by convenience sampling who presented for check-up in the Eye Department of community ophthalmology, Bangabandhu Sheikh Mujib Medical University, Dhaka. Bangladesh. Results:A total of 120 eyes in 60 patients were studied. The mean age of the patients was 41.60 year. study population consisted of 24 (40 % men and 36 (60 % women. The mean intraocular pressure was 13.52 &13.72 mmHg for GAT, and 16.64 & 17.44 mmHg for Air puff respectively. The range of measurements by GAT was from 10 to 23 mmHg and by Air puff was 12 to 28mmHg. The difference between IOP measured by two instruments were statistically significant (p=0.000.Conclusion: Airpuff tonometer is quick, a non-contact method to measure intraocular pressure and is useful for screening purposes and postoperative case but the measurements should be confirmed with Goldmann applanation tonometer for accurate labelling

Preparation of inorganic hydrophobic catalysts

International Nuclear Information System (INIS)

Yang, Yong; Wang, Heyi; Du, Yang

2009-04-01

In order to catalyse the oxidation of tritium gas, two inorganic hydrophobic catalysts are prepared. Under room temperature, the catalysed oxidation ratio of 0.3%-1% (V/V) hydrogen gas in air is higher than 95%. Pt-II inorganic hydrophobic catalysts has obviously better catalysing ability than Pt-PTFE and lower ability than Pt-SDB in H 2 -HTO isotopic exchange, because the pressure resistence of Pt-II is much higher than Pt-SDB, it can be used to the CECE cell of heavy water detritium system. (authors)

Radioluminescence of polyester resin modified with acrylic acid and its salts

Science.gov (United States)

Szalińska, H.; Wypych, M.; Pietrzak, M.; Szadkowska-Nicze, M.

Polimal-109 polyester resin and its compounds containing acrylic acid and its salts such as: sodium, potassium, magnesium, calcium, barium, iron, cobalt, copper and manganese acrylates were studied by the radioluminescence method, including isothermal luminescence (ITL) at a radiation temperature of 77 K, thermoluminescence (RTL) and spectral distributions of isothermal luminescence. Measurements of optical absorption at 77 K before and after irradiation of the investigated samples were also carried out. The results obtained have shown that metal ions play a significant part in the processes taking place in the polyester matrix under the influence of γ 60Co radiation.

Radioluminescence of polyester resin modified with acrylic acid and its salts

International Nuclear Information System (INIS)

Szalinska, H.; Wypych, M.; Pietrzak, M.; Szadkowska-Nicze, M.

1987-01-01

Polimal-109 polyester resin and its compounds containing acrylic acid and its salts such as: sodium, potassium, magnesium, calcium, barium, iron, cobalt, copper and manganese acrylates were studied by the radioluminescence method, including isothermal luminescence (ITL) at a radiation temperature of 77 K, thermoluminescence (RTL) and spectral distributions of isothermal luminescence. Measurements of optical absorption at 77K before and after irradiation of the investigated samples were also carried out. The results obtained have shown that metal ions play a significant part in the processes taking place in the polyester matrix under the influence of γ 60 Co radiation. (author)

Self-Compacting Concrete Incorporating Micro-SiO2 and Acrylic Polymer

Directory of Open Access Journals (Sweden)

Ali Heidari

2014-01-01

Full Text Available This study examined the effects of using acrylic polymer and micro-SiO2 in self-compacting concrete (SCC. Using these materials in SCC improves the characteristics of the concrete. Self-compacting samples with 1-2% of a polymer and 10% micro-SiO2 were made. In all cases, compressive strength, water absorption, and self-compacting tests were done. The results show that adding acrylic polymer and micro-SiO2 does not have a significant negative effect on the mechanical properties of self-compacting concrete. In addition using these materials leads to improving them.

Stronger multilayer acrylic dielectric elastomer actuators with silicone gel coatings

Science.gov (United States)

Lau, Gih-Keong; La, Thanh-Giang; Sheng-Wei Foong, Ervin; Shrestha, Milan

2016-12-01

Multilayer dielectric elastomer actuators (DEA) perform worst off than single-layer DEAs due to higher susceptibility to electro-thermal breakdown. This paper presents a hot-spot model to predict the electro-thermal breakdown field of DEAs and its dependence on thermal insulation. To inhibit the electrothermal breakdown, silicone gel coating was applied as barrier coating to multilayer acrylic DEA. The gel coating helps suppress the electro-thermally induced puncturing of DEA membrane at the hot spot. As a result, the gel-coated DEAs, in either a single layer or a multilayer stack, can produce 30% more isometric stress change as compared to those none-coated. These gel-coated acrylic DEAs show great potential to make stronger artificial muscles.

Hydrophobic mismatch in gramicidin A'/lecithin systems

International Nuclear Information System (INIS)

Watnick, P.I.; Chan, S.I.; Dea, P.

1990-01-01

Gramicidin A' (GA') has been added to three lipid systems of varying hydrophobic thickness: dimyristoyllecithin (DML), dipalmitoyllecithin (DPL), and distearoyllecithin (DSL). The similarity in length between the hydrophobic portion of GA' and the hydrocarbon chains of the lipid bilayers has been studied by using 31 P and 2 H NMR. Hydrophobic mismatch has been found to be most severe in the DML bilayer system and minimal in the case of DSL. In addition, the effects of hydrophobic mismatch on the cooperative properties of the bilayer have been obtained from 2 H NMR relaxation measurements. The results indicate that incorporation of the peptide into the bilayer disrupts the cooperative director fluctuations characteristic of pure multilamellar lipid dispersions. Finally, the GA'/lecithin ratio at which the well-known transformation from bilayer to reverse hexagonal (H II ) phase occurs is shown to depend on the acyl chain length of the phospholipid. A rationale is proposed for this chain length dependence

Intraocular surgery in a large diabetes patient population

DEFF Research Database (Denmark)

Ostri, Christoffer

2014-01-01

The prevalence of diabetes is on the increase in developed countries. Accordingly, the prevention and treatment of vision-threatening diabetic eye complications is assuming greater importance. The overall aim of this thesis is to analyse risk factors for intraocular surgery in a large diabetes po...... surgery, which can be used for preventive purposes, surgical decision-making and patient counselling....

Investigation into nanocellulosics versus acacia reinforced acrylic films

Science.gov (United States)

Yunqiao Pu; Jianguo Zhang; Thomas Elder; Yulin Deng; Paul Gatenholm; Arthur J. Ragauskas

2007-01-01

Three closely related cellulosic acrylic latex films were prepared employing acacia pulp fibers, cellulose whiskers and nonocellulose balls and their respective strength properties were determined. Cellulose whisker reinforced composites had enhanced strength properties compared to the acacia pulp and nanoball composites. AFM analysis indicated that the cellulose...

Decarboxylation-based traceless linking with aroyl acrylic acids

DEFF Research Database (Denmark)

Nielsen, John

1998-01-01

beta-Keto carboxylic acids are known to decarboxylate readily. In our pursuit to synthesize beta-indolinyl propiophenones, we have exploited this chemistry as a mean of establishing a traceless handle. 2-Aroyl acrylic acids have been esterified to a trityl resin, after which Michael-type addition...

Radiation Induced Grafting of Acrylate onto Waste Rubber: The Effect of Monomer Type

Directory of Open Access Journals (Sweden)

Shirajuddin Siti Salwa M.

2017-01-01

Full Text Available The effect of three different acrylate group monomers, namely n-butyl acrylate, methacrylic acid and tripropylene glycol diacrylate of radiation induced grafting onto waste rubber was studied. The electron beam accelerator operated at voltage of 2MeV was used to irradiate the waste rubber at 10 kGy and 100 kGy absorbed radiation dose, respectively. The formation of grafting was observed from the increase in the grafting yield and confirmed by Transformed Infra-Red Spectroscopy results. According to the result obtained, only tripropylene glycol diacrylate was selected to graft onto waste rubber. The carbonyl bond from acrylate groups was seen at 1726 cm-1 band which confirmed the presence of TPGDA in the polymer matrix. This indicates the successful preparation of the TPGDA-grafted waste rubber via radiation induced grafting techniques.

Improvement of Tenofovir vaginal release from hydrophilic matrices through drug granulation with hydrophobic polymers.

Science.gov (United States)

Notario-Pérez, Fernando; Martín-Illana, Araceli; Cazorla-Luna, Raúl; Ruiz-Caro, Roberto; Peña, Juan; Veiga, María-Dolores

2018-05-30

Sustained-release vaginal microbicides hold out great hope for the prevention of sexual transmission of HIV from men to women. Tenofovir (TFV) -an antiretroviral drug- sustained-release vaginal compacts combining two release control systems (by drug-loading granules with hydrophobic polymers and incorporating them in a hydrophilic matrix) are proposed in this work as a possible microbicide. The polymers used for the drug granules are Eudragit® RS (ERS), an acrylic derivative, and Zein, a maize protein. The hydrophilic matrix is composed of a mixture of hydroxypropylmethyl cellulose (HPMC) and chitosan (CH). The thermal, microscopic, spectrophotometric and X-ray diffraction analysis showed that the drug was not altered during the granulation process. Studies of TFV release, swelling and ex vivo mucoadhesion were subsequently performed on simulated vaginal fluid. The formulation whereby TFV is granulated using twice its weight in ERS, and then including these granules in a matrix in which the CH predominates over HPMC, allows the sustained release of TFV for 144 h, mucoadhesion to the vaginal mucosa for 150 h and a moderate swelling, making it the most suitable formulation of all those studied. These compacts would therefore offer women protection against the sexual acquisition of HIV. Copyright © 2018 Elsevier B.V. All rights reserved.

Antireflection coatings for intraocular lenses of sapphire and fianite

Energy Technology Data Exchange (ETDEWEB)

Babin, A.A.; Konoplev, Yu.N.; Mamaev, Yu.A. [Inst. of Applied Physics, Nizhnii Novgorod (Russian Federation)] [and others

1995-10-01

Broadband antireflection coatings for intraocular lenses of sapphire and fianite are calculated and implemented practically. Their residual reflectance in the liquid with a refracting index of 1.336 is below 0.2% from each face virtually over the entire visible region. 7 refs., 2 figs., 2 tabs.

Straylight from glistenings in intraocular lenses : In vitro study

NARCIS (Netherlands)

Łabuz, Grzegorz; Reus, Nicolaas J; van den Berg, Thomas J T P

PURPOSE: To assess light scattering from intraocular lenses (IOLs) with different numbers of laboratory-induced glistenings and create a model for predicting glistening effects on straylight. SETTING: Rotterdam Ophthalmic Institute, Rotterdam, the Netherlands. DESIGN: Experimental study. METHODS:

Synthesis of Highly Porous Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) Asymmetric Membranes

KAUST Repository

Xie, Yihui; Moreno Chaparro, Nicolas; Calo, Victor M.; Cheng, Hong; Hong, Pei-Ying; Sougrat, Rachid; Behzad, Ali Reza; Tayouo Djinsu, Russell; Nunes, Suzana Pereira

2016-01-01

For the first time, self-assembly and non-solvent induced phase separation was applied to polysulfone-based linear block copolymers, reaching mechanical stability much higher than other block copolymers membranes used in this method, which were mainly based on polystyrene blocks. Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) (PtBA30k-b-PSU14k-b-PtBA30k) with a low polydispersity of 1.4 was synthesized by combining step-growth condensation and RAFT polymerization. Various advanced electron microscopies revealed that PtBA30k-b-PSU14k-b-PtBA30k assembles into worm-like cylindrical micelles in DMAc and adopts a “flower-like” arrangement with the PSU central block forming the shell. Computational modeling described the mechanism of micelle formation and morphological transition. Asymmetric nanostructured membranes were obtained with a highly porous interconnected skin layer and a sublayer with finger-like macrovoids. Ultrafiltration tests confirmed a water permeance of 555 L m-2 h-1 bar-1 with molecular weight cut-off of 28 kg/mol. PtBA segments on the membrane surface were then hydrolyzed and complexed with metals, leading to cross-linking and enhancement of antibacterial capability.

Synthesis of Highly Porous Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) Asymmetric Membranes

KAUST Repository

Xie, Yihui

2016-03-24

For the first time, self-assembly and non-solvent induced phase separation was applied to polysulfone-based linear block copolymers, reaching mechanical stability much higher than other block copolymers membranes used in this method, which were mainly based on polystyrene blocks. Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) (PtBA30k-b-PSU14k-b-PtBA30k) with a low polydispersity of 1.4 was synthesized by combining step-growth condensation and RAFT polymerization. Various advanced electron microscopies revealed that PtBA30k-b-PSU14k-b-PtBA30k assembles into worm-like cylindrical micelles in DMAc and adopts a “flower-like” arrangement with the PSU central block forming the shell. Computational modeling described the mechanism of micelle formation and morphological transition. Asymmetric nanostructured membranes were obtained with a highly porous interconnected skin layer and a sublayer with finger-like macrovoids. Ultrafiltration tests confirmed a water permeance of 555 L m-2 h-1 bar-1 with molecular weight cut-off of 28 kg/mol. PtBA segments on the membrane surface were then hydrolyzed and complexed with metals, leading to cross-linking and enhancement of antibacterial capability.

Hydrophobic core substitutions in calbindin D9k

DEFF Research Database (Denmark)

Kragelund, B B; Jönsson, M; Bifulco, G

1998-01-01

Hydrophobic core residues have a marked influence on the Ca2+-binding properties of calbindin D9k, even though there are no direct contacts between these residues and the bound Ca2+ ions. Eleven different mutants with substitutions in the hydrophobic core were produced, and their equilibrium Ca2+...... that the hydrophobic core residues promote Ca2+ binding both by contributing to the preformation of the Ca2+ sites in the apo state and by preferentially stabilizing the Ca2+-bound state.......Hydrophobic core residues have a marked influence on the Ca2+-binding properties of calbindin D9k, even though there are no direct contacts between these residues and the bound Ca2+ ions. Eleven different mutants with substitutions in the hydrophobic core were produced, and their equilibrium Ca2...... that the mutation causes only very minimal perturbations in the immediate vicinity of residue 61. Substitutions of alanines or glycines for bulky residues in the center of the core were found to have significant effects on both Ca2+ affinity and dissociation rates. These substitutions caused a reduction in affinity...

Brachytherapy with cobalt plaques in the conservative treatment of intraocular tumors. The Brazilian experience

International Nuclear Information System (INIS)

Pellizzon, Antonio Cassio Assis; Trippe, N.; Novaes, P.E.; Ferrigno, R.; Fogarolli, R.C.; Maia, M.A.C.; Salvajoli, J.V.; Baraldi, H.E.; Chojniak, M.M.; Erwene, C.M.

1996-01-01

Purpose/Objective: To show the retrospective results of intraocular tumors, including uveal melanomas and retinoblastomas treated by exclusive brachytherapy with cobalt plaques. The goal was to keep the vision function with not compromising the chance of cure. Materials and Methods: From December 1989 to December 1993, 76 cases of intraocular tumors, being 56 adult patients with uveal melanomas and 20 children with retinoblastoma, were treated with exclusive intraocular brachytherapy through cobalt plaques. The prescribed dose was 40 Gy, calculated at the apex of the lesion for retinoblastomas and 100 Gy for melanomas. The selection criteria included those introcular lesions with diameter until 15 mm. Results: With the minimum follow up of 24 months, of the 56 patients with uveal melanomas, 41 (73,3%) had their vision preserved with no evidence of disease, while 15 (26,4%) had local failure and were underwent to enucleation. With the medium follow up of 27 months, of the 20 patients with retinoblastoma, 17 (85,5%) had their vision preserved with no evidence of disease, while 3 (15%) had local failure and were underwent to enucleation. All patients are alive with no evidence of systemic disease. Conclusion: When well indicated, the conservative treatment of intraocular tumors with brachytherapy is a good alternative to enucleation and must be done by a multidisciplinary and well trained medical team

Corn silk aqueous extracts and intraocular pressure of systemic and non-systemic hypertensive subjects.

Science.gov (United States)

George, Gladys O; Idu, Faustina K

2015-03-01

Hypotensive properties have been attributed to the stigma/style of Zea mays L (corn silk). Although the effect of corn silk extract on blood pressure has been documented in animal studies, we are not aware of any study on its effect on human blood pressure and intraocular pressure. A randomised study was carried out on the effect of water only, masked doses of corn silk aqueous extract (60, 130, 192.5 and 260 mg/kg body weight) on intraocular pressure and blood pressure of 20 systemic and 20 non-systemic hypertensive subjects. Intraocular pressure and blood pressure were measured at baseline and every hour for eight hours after administering water or a masked dose of corn silk aqueous extract. Each dose was administered at two-week intervals to each subject in the two study groups. The results showed that the last three doses of corn silk aqueous extract gave a statistically significant reduction (p Corn silk aqueous extract has a lowering effect on intraocular pressure in systemic and non-systemic hypertensive subjects. This may have resulted from the fall in blood pressure that is due to potassium-induced natriuresis and diuresis caused by the high potassium content in the high doses of the corn silk extract. © 2015 The Authors. Clinical and Experimental Optometry © 2015 Optometry Australia.

Controllable picoliter pipetting using hydrophobic microfluidic valves

Science.gov (United States)

Zhang, M.; Huang, J.; Qian, X.; Mi, S.; Wang, X.

2017-06-01

A picoliter pipetting technique using the microfluidic method is presented. Utilizing the hydrophobic self-assembled monolayer films patterned in microchannels as pressure-controlled valves, a small volume of liquid can be separated by a designed channel trap and then ejected from the channel end at a higher pressure. The liquid trap section is composed of a T-shaped channel junction and a hydrophobic patch. The liquid volume can be precisely controlled by varying the distance of the hydrophobic patch from the T-junction. By this means, liquid less than 100 pl can be separated and pipetted. The developed device is potentially useful for sample dispensing in biological, medical, and chemical applications.

Socioeconomic and psychological impact of treatment for unilateral intraocular retinoblastoma.

Science.gov (United States)

Soliman, S E; Dimaras, H; Souka, A A; Ashry, M H; Gallie, B L

2015-06-01

To identify the socioeconomic and psychosocial impacts of clinical treatment decisions for advanced unilateral intraocular retinoblastoma. Retrospective observational case series. institutional study at Alexandria Main University Hospital. records of 66 unilateral retinoblastoma cases treated from May 2005 to May 2013 were retrospectively reviewed. Sixty cases were eligible (International Intraocular Retinoblastoma Classification [IIRC] group C, D or E). two treatment groups were compared: enucleation vs. salvage treatment. Salvage treatment eyes were further subdivided based on IIRC group. Six socioeconomic parameters (financial burden, financial impact, psychological, social, medical and tumor impacts) were scored. Parameter scores ranged from 0 to 3, for overall score range 0 (no adverse impact) to 18 (severe adverse impact). derived Socioeconomic scores were correlated with treatment and outcomes. The enucleation group (28 eyes) had a median overall Socioeconomic score of 4/18, significantly lower than the salvage treatment group (32 eyes), median score 11/18 (PSocioeconomic score varied with IIRC group. Attempted eye salvage failed in 25 children, due to uncontrolled tumor (44%) and socioeconomic impact of cumulative therapies (56%). Treatment duration and Socioeconomic score were higher for the 5 children in the salvage treatment group who developed metastatic disease compared to those without metastasis (Psocioeconomic and psychosocial impacts of attempted ocular salvage for unilateral intraocular retinoblastoma are severe, in comparison to primary enucleation. Primary enucleation is a good treatment for unilateral retinoblastoma. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Surface coating of jeungjing wood (Paraserianthes Falcataria (L) NIELSEN) with acrylate resins by using radiation technique

International Nuclear Information System (INIS)

Suhariyono, Gatot

1998-01-01

An experiment on surface coating with acrylate resins has been done by using radiation technique to improve the quality and added value of jeunjing wood (Paraserianthes Falcataria (L) NIELSEN). Doses used in Electron Beam (BE) radiation were 20, 40, and 60 kGy. Epoxy acrylate and ester acrylate resins were used as coating materials after added with tripropylene glycol diacylate (TPGDA) monomer, 2,2-dimethyl-2hidroxy acetophenone (Darocur 1173) photoinitiator and talc as base coat. Top coat consists of este acrylate Setacure AM 548, after added with titanium dioxide OK 412 as additive respectively. Titanium dioxides in the mixture were varied at the concentration level of 0, 2, 4 and 6 % by weight. Conventional coating as comparison was carried out by using varnish as coating material. The results showed that the properties of film on jeunjing wood by EB curing are better than that of conventional one. (authors)

The Advanced Glaucoma Intervention Study (AGIS): 7. The relationship between control of intraocular pressure and visual field deterioration.The AGIS Investigators.

Science.gov (United States)

2000-10-01

To investigate the association between control of intraocular pressure after surgical intervention for glaucoma and visual field deterioration. In the Advanced Glaucoma Intervention Study, eyes were randomly assigned to one of two sequences of glaucoma surgery, one beginning with argon laser trabeculoplasty and the other trabeculectomy. In the present article we examine the relationship between intraocular pressure and progression of visual field damage over 6 or more years of follow-up. In the first analysis, designated Predictive Analysis, we categorize 738 eyes into three groups based on intraocular pressure determinations over the first three 6-month follow-up visits. In the second analysis, designated Associative Analysis, we categorize 586 eyes into four groups based on the percent of 6-month visits over the first 6 follow-up years in which eyes presented with intraocular pressure less than 18 mm Hg. The outcome measure in both analyses is change from baseline in follow-up visual field defect score (range, 0 to 20 units). In the Predictive Analysis, eyes with early average intraocular pressure greater than 17.5 mm Hg had an estimated worsening during subsequent follow-up that was 1 unit of visual field defect score greater than eyes with average intraocular pressure less than 14 mm Hg (P =.002). This amount of worsening was greater at 7 years (1.89 units; P <.001) than at 2 years (0.64 units; P =.071). In the Associative Analysis, eyes with 100% of visits with intraocular pressure less than 18 mm Hg over 6 years had mean changes from baseline in visual field defect score close to zero during follow-up, whereas eyes with less than 50% of visits with intraocular pressure less than 18 mm Hg had an estimated worsening over follow-up of 0.63 units of visual field defect score (P =.083). This amount of worsening was greater at 7 years (1.93 units; P <.001) than at 2 years (0.25 units; P =.572). In both analyses low intraocular pressure is associated with reduced

Effect of Microwave Cured Acrylic Resin on Candidal Growth in Complete denture

International Nuclear Information System (INIS)

Rasmy, A.H.M.

2009-01-01

This study was conducted to evaluate the effect of heat-cured acrylic resin denture base and microwave-cured acrylic resin denture base on Candidal growth. Seven completely edentulous male patients with no history of denture wearing participated in this study. All the selected patients were re-habilitated by mucosa supported complete dentures. The dentures were constructed from conventional heat-cured acrylic resin denture base following monoplane concept of occlusion. Before dismissing the patients and one month after denture insertion, salivary samples were collected according to oral rinse technique. One month resting period was allowed so as Candidal count can reach to normal. Then dentures were re based using microwave-cured acrylic denture base, before denture insertion and one month after denture insertion, salivary sample were collected before and one month following the same oral rinse technique. In the oral rinse technique, the patients were instructed to rinse their mouths with 10 mL of sterile phosphate buffered saline for 60 seconds. The rinse was then expectorated into a universal container and immediately transported to the laboratory for concentration by centrifugation, then cultured on sabouraud's dextrose agar plates which were incubated at 37 degree C for 48 hours. Microscopic examination and germ tube test were carried out for laboratory investigations. In addition, the morphological features of the isolated Candida from the samples tested in this study, were investigated using the scanning electron microscope(SEM)