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Sample records for ocular surface area

  1. Ocular surface tumors

    PubMed Central

    Othman, Ihab Saad

    2009-01-01

    Tumors of the conjunctiva and cornea comprise a large and varied spectrum of conditions. These tumors are grouped into two major categories of congenital and acquired lesions. The acquired lesions are further subdivided based on origin of the mass into surface epithelial, mucoepidermoid, melanocytic, vascular, fibrous, neural, histiocytic, myxoid, myogenic, lipomatous, lymphoid, leukemic, metastatic and secondary tumors. Ocular surface tumors include a variety of neoplasms originating from squamous epithelium, melanocytic tumors and lymphocytic resident cells of the conjunctival stroma. In this review, we highlight clinical features of these lesions, important diagnostic and investigative tools and standard care of management. PMID:21234217

  2. Ocular surface reconstruction update.

    PubMed

    Shimmura, Shigeto; Tsubota, Kazuo

    2002-08-01

    Ocular surface reconstruction (OSR) is now a standard procedure in the treatment of severe ocular surface disorders. The past few years have revealed the long-term results of patients who were operated on during the early stages of OSR development, and we now have a more realistic view of the benefits and limits of the procedure. On the other hand, further understanding of the physiologic role played by the amniotic membrane (AM) has opened doors to further refined techniques in treating these patients. This review will introduce some of the major contributions made during the past years in the advancement of OSR. Clinically, we are at a stage of reviewing the pros and cons of the various transplantation techniques. Identification of factors crucial for a successful OSR procedure will further improve surgical results. Basic researchers are on the verge of identifying the so-called limbal stem cells, and further understanding of AM physiology will lead the way to tissue engineering techniques as another alternative in OSR surgery.

  3. Ocular surface temperature.

    PubMed

    Efron, N; Young, G; Brennan, N A

    1989-09-01

    A wide-field color-coded infra-red imaging device was applied to the measurement of i) the temperature profile across the ocular surface and ii) the temporal stability of central corneal temperature, on 21 subjects. The thermographs showed a pattern of ellipsoidal isotherms (major axis horizontal) approximately concentric about a temperature apex (coldest point) which was slightly inferior to the geometric center of the cornea (GCC). The GCC had a mean temperature (+/- SD) of 34.3 +/- 0.7 degrees C (range 32.8 to 35.4 degrees C). Temperature increased towards the periphery of the cornea with the limbus being 0.45 degrees C warmer than the GCC (p less than 0.0001). Following a blink, the GCC cooled at a mean (+/- SD) rate of 0.033 +/- 0.024 degrees C/s (p less than 0.0001) over the first 15s. Subjects whose corneas cooled more slowly following a blink demonstrated a greater capacity to avoid blinking for a prolonged period (p less than 0.05). This improved method of measuring ocular surface temperature has important applications in modeling corneal physiology and pathology.

  4. Ocular surface sealants and adhesives.

    PubMed

    Bhatia, Subir Singh

    2006-07-01

    Tissue adhesives, both synthetic and biologic, have a long history of use in ophthalmology. Cyanoacrylate-based glues have traditionally been the most widely used glues for various purposes. They have been specially useful for treating corneal perforations and have had significantly improved long-term outcomes. More recently, fibrin-based glues have gained a major role as a suture substitute for attaching biologic tissues and as surface sealants. The literature supports expanded use of fibrin glue in this fashion. Other new agents, such as polyethyelene glycols, have been underutilized and hold promise, especially as surface protectants. Numerous other glues are being developed and show promise as ocular surface sealants and protective membranes. Advances in knowledge about tissue adhesives are leading to more effective and efficient ophthalmic care.

  5. The ocular surface: from physiology to the ocular allergic diseases.

    PubMed

    Galicia-Carreón, Jorge; Santacruz, Concepción; Hong, Enrique; Jiménez-Martínez, María C

    2013-01-01

    Allergic conjunctivitis (AC) is an inflammation of the conjunctiva secondary to an immune response to exogenous antigens, usually called allergens. In fact, AC is a syndrome that involves the entire ocular surface, including conjunctiva, lids, cornea, and tear film. The signs and symptoms of AC have a meaningful effect on comfort and patient health, and could be influenced by environment, genetics and immune regulation mechanisms, all of which work together in a complex immunological homeostasis. Dysregulation in such immune responses could turn into a variety of ocular allergic diseases (OAD). This review describes some of the current understanding of cellular and molecular pathways involved in different OAD.

  6. Immunomodulation on the ocular surface: a review

    PubMed Central

    Szaflik, Jerzy; Szaflik, Jacek P.; Ambroziak, Maciej; Witkiewicz, Jan; Skopiński, Piotr

    2016-01-01

    The increasing understanding of immune mechanisms changed our perception of the ocular surface, which is now considered a compartment of the common mucosal immune system. It offered the possibility to alter the physiological immune response on the ocular surface and effectively combat inflammation, which impairs stability of the tear film and causes tear hyperosmolarity, causing symptoms of dry eye disease. The paper provides an overview of ocular surface anatomy and physiology, explains the underlying mechanisms of dry eye disease and discusses novel and promising treatment modalities, such as cyclosporine A, biological therapies using autologous serum and various growth factors as well as experimental treatment methods which are currently being investigated. PMID:27536206

  7. Platelet rich plasma in ocular surface.

    PubMed

    Riestra, A C; Alonso-Herreros, J M; Merayo-Lloves, J

    2016-10-01

    The use of platelet-rich preparations has experienced a significant increase in recent years due to its role in tissue-repair and regeneration. The aim of this study is to examine the available evidence regarding the application of plasma rich in growth factors, and its variations, on the ocular surface. A review is also presented on the effects of platelet-derived growth factors, the implications of the preparation methods, and the existing literature on the safety and efficacy of these therapies in ocular surface diseases. Despite the widespread use of platelet preparations there is no consensus on the most appropriate preparation method, and growth factors concentration vary with different systems. These preparations have been used in the treatment of ocular surface diseases, such as dry eye or persistent epithelial defects, among others, with good safety and efficacy profiles, but further studies are needed to compare to the currently available alternatives.

  8. Cultured corneal epithelia for ocular surface disease.

    PubMed Central

    Schwab, I R

    1999-01-01

    PURPOSE: To evaluate the potential efficacy for autologous and allogeneic expanded corneal epithelial cell transplants derived from harvested limbal corneal epithelial stem cells cultured in vitro for the management of ocular surface disease. METHODS: Human Subjects. Of the 19 human subjects included, 18 (20 procedures) underwent in vitro cultured corneal epithelial cell transplants using various carriers for the epithelial cells to determine the most efficacious approach. Sixteen patients (18 procedures on 17 eyes) received autologous transplants, and 2 patients (1 procedure each) received allogeneic sibling grafts. The presumed corneal epithelial stem cells from 1 patient did not grow in vitro. The carriers for the expanded corneal epithelial cells included corneal stroma, type 1 collagen (Vitrogen), soft contact lenses, collagen shields, and amniotic membrane for the autologous grafts and only amniotic membrane for the allogeneic sibling grafts. Histologic confirmation was reviewed on selected donor grafts. Amniotic membrane as carrier. Further studies were made to determine whether amniotic membrane might be the best carrier for the expanding corneal epithelial cells. Seventeen different combinations of tryspinization, sonication, scraping, and washing were studied to find the simplest, most effective method for removing the amniotic epithelium while still preserving the histologic appearance of the basement membrane of the amnion. Presumed corneal epithelial stem cells were harvested and expanded in vitro and applied to the amniotic membrane to create a composite graft. Thus, the composite graft consisted of the amniotic membrane from which the original epithelium had been removed without significant histologic damage to the basement membrane, and the expanded corneal epithelial stem cells, which had been applied to and had successfully adhered to the denuded amniotic membrane. Animal model. Twelve rabbits had the ocular surface of 1 eye damaged in a standard

  9. [Ocular surface investigations in dry eye].

    PubMed

    Labbé, A; Brignole-Baudouin, F; Baudouin, C

    2007-01-01

    Dry eye is a complex clinicopathological entity involving tear film, lacrimal glands, eyelids, and a wide spectrum of ocular surface cells, including epithelial, inflammatory, immune, and goblet cells. From the tightly regulated lacrimal film functions and structure, a large variety of investigations have been developed, including tear meniscus measurements, fluorophotometry, meibometry, interference pattern analysis, evaporation rate, tear osmolarity, and thermography. Dry eye conditions also interfere with the ocular surface, causing corneal irregularities that may be explored using the techniques of videokeratography and in vivo confocal microscopy, or optical impairment, as confirmed by aberrometry. At the level of ocular surface cells, impression cytology remains a standard for assessing cell alterations. It has greatly benefited from new confocal microscopy, molecular biology, and flow cytometry techniques. Biological assessment of tear proteins or other mediators is also useful. Major limits should be acknowledged, however, such as technical issues in tear film collection, especially in dry eyes, and the lack of standardization of most measurements. Tear osmolarity, electrophoresis, and dosage of normal tear proteins, such as lysozyme or lactoferrin, remain the most useful tests. Finally, some extraocular explorations such as accessory gland biopsy or serum antinuclear antibody dosage may be useful for assessing the diagnosis of Sjögren's syndrome.

  10. Silk film biomaterials for ocular surface repair

    NASA Astrophysics Data System (ADS)

    Lawrence, Brian David

    Current biomaterial approaches for repairing the cornea's ocular surface upon injury are partially effective due to inherent material limitations. As a result there is a need to expand the biomaterial options available for use in the eye, which in turn will help to expand new clinical innovations and technology development. The studies illustrated here are a collection of work to further characterize silk film biomaterials for use on the ocular surface. Silk films were produced from regenerated fibroin protein solution derived from the Bombyx mori silkworm cocoon. Methods of silk film processing and production were developed to produce consistent biomaterials for in vitro and in vivo evaluation. A wide range of experiments was undertaken that spanned from in vitro silk film material characterization to in vivo evaluation. It was found that a variety of silk film properties could be controlled through a water-annealing process. Silk films were then generated that could be use in vitro to produce stratified corneal epithelial cell sheets comparable to tissue grown on the clinical standard substrate of amniotic membrane. This understanding was translated to produce a silk film design that enhanced corneal healing in vivo on a rabbit injury model. Further work produced silk films with varying surface topographies that were used as a simplified analog to the corneal basement membrane surface in vitro. These studies demonstrated that silk film surface topography is capable of directing corneal epithelial cell attachment, growth, and migration response. Most notably epithelial tissue development was controllably directed by the presence of the silk surface topography through increasing cell sheet migration efficiency at the individual cellular level. Taken together, the presented findings represent a comprehensive characterization of silk film biomaterials for use in ocular surface reconstruction, and indicate their utility as a potential material choice in the

  11. Ocular Surface as Barrier of Innate Immunity

    PubMed Central

    Bolaños-Jiménez, Rodrigo; Navas, Alejandro; López-Lizárraga, Erika Paulina; de Ribot, Francesc March; Peña, Alexandra; Graue-Hernández, Enrique O; Garfias, Yonathan

    2015-01-01

    Sight is one of the most important senses that human beings possess. The ocular system is a complex structure equipped with mechanisms that prevent or limit damage caused by physical, chemical, infectious and environmental factors. These mechanisms include a series of anatomical, cellular and humoral factors that have been a matter of study. The cornea is not only the most powerful and important lens of the optical system, but also, it has been involved in many other physiological and pathological processes apart from its refractive nature; the morphological and histological properties of the cornea have been thoroughly studied for the last fifty years; drawing attention in its molecular characteristics of immune response. This paper will review the anatomical and physiological aspects of the cornea, conjunctiva and lacrimal apparatus, as well as the innate immunity at the ocular surface. PMID:26161163

  12. An examination of the relationship between ocular surface tear osmolarity compartments and epitheliopathy.

    PubMed

    McMonnies, Charles W

    2015-04-01

    A 2014 PubMed search for tear hyperosmolarity and corneal stain yielded 2960 results. Selections from those providing evidence of variations in osmolarity were used to refine the compartmentalization model of tear osmolarity over the ocular surface. This new model includes the low point of freshly produced isotonic tears in the upper conjunctival sac, with osmolarity increasing successively in the upper meniscus, the upper area of exposed ocular surface, the lower area of over-exposed ocular surface, the lower meniscus, and the lower conjunctival sac. Compartmentalization is used to explain epitheliopathy over the ocular surface as resulting from variable degrees of exposure to hyperosmolarity-induced insult and/or friction-related mechanical damage. Also recognized is the role of localized increases in osmolarity, which appear likely to occur in the black lines and tear breakup areas of the exposed ocular surface. Variables such as the influence of ambient conditions of air humidity, temperature and movement have been considered, as well as rates of complete and incomplete blinks and associated potential for over-exposure of the inferior area of the normally exposed ocular surface. The exacerbating contribution from contact lens wear has been included. Friction-related damage may be the primary basis for lid wiper epitheliopathy, but tear hyperosmolarity could have an important contributory role. Subcompartmental consideration of variation in osmolarity may improve understanding of different presentations of epitheliopathy.

  13. Relationship between ocular surface temperature and peripheral vasoconstriction in healthy subjects: a thermographic study.

    PubMed

    Vannetti, Federica; Matteoli, Sara; Finocchio, Lucia; Lacarbonara, Francesco; Sodi, Andrea; Menchini, Ugo; Corvi, Andrea

    2014-03-01

    An impairment of ocular blood flow regulation is commonly considered one of the main pathogenetic mechanisms involved in the development of several eye diseases, like glaucoma. The aim of this study was to investigate whether an alteration of ocular blood supply induced by peripheral vasoconstriction might be detected by measuring the ocular surface temperature. The ocular surface temperature was evaluated in a group of 38 healthy young subjects (28 males and 10 females; mean age: 25.4 ± 4.1 years) by infrared thermography. For each subject, the experimental procedure consisted of two thermographic acquisitions both lasting 10 s, recorded before and during the immersion of both hands in a mixture of ice and water (1.6 °C ± 0.4 °C). Specifically, the second acquisition began 20 s after the hand immersion. Analysis of variance was used to compare the ocular surface temperature of the two profiles. The analysis of infrared images was carried out every 2 s: at the eye opening (t(0)) until 10 s (t(5)), for both profiles. Data showed that ocular surface temperature increased significantly (p-value < 0.05), especially near the sources of ocular blood supply, that is, temporal and nasal areas (mean increasing temperature at t(0) for P(1) = 0.12 °C ± 0.13 °C). Therefore, these results suggest a response of the ocular hemodynamic to the peripheral vasoconstriction. The ocular surface temperature may represent a cheap, non-invasive and non-time-consuming test to evaluate ocular vaso-regulation.

  14. Clusterin Seals the Ocular Surface Barrier in Mouse Dry Eye.

    PubMed

    Bauskar, Aditi; Mack, Wendy J; Mauris, Jerome; Argüeso, Pablo; Heur, Martin; Nagel, Barbara A; Kolar, Grant R; Gleave, Martin E; Nakamura, Takahiro; Kinoshita, Shigeru; Moradian-Oldak, Janet; Panjwani, Noorjahan; Pflugfelder, Stephen C; Wilson, Mark R; Fini, M Elizabeth; Jeong, Shinwu

    2015-01-01

    Dry eye is a common disorder caused by inadequate hydration of the ocular surface that results in disruption of barrier function. The homeostatic protein clusterin (CLU) is prominent at fluid-tissue interfaces throughout the body. CLU levels are reduced at the ocular surface in human inflammatory disorders that manifest as severe dry eye, as well as in a preclinical mouse model for desiccating stress that mimics dry eye. Using this mouse model, we show here that CLU prevents and ameliorates ocular surface barrier disruption by a remarkable sealing mechanism dependent on attainment of a critical all-or-none concentration. When the CLU level drops below the critical all-or-none threshold, the barrier becomes vulnerable to desiccating stress. CLU binds selectively to the ocular surface subjected to desiccating stress in vivo, and in vitro to the galectin LGALS3, a key barrier component. Positioned in this way, CLU not only physically seals the ocular surface barrier, but it also protects the barrier cells and prevents further damage to barrier structure. These findings define a fundamentally new mechanism for ocular surface protection and suggest CLU as a biotherapeutic for dry eye.

  15. Clusterin Seals the Ocular Surface Barrier in Mouse Dry Eye

    PubMed Central

    Bauskar, Aditi; Mack, Wendy J.; Mauris, Jerome; Argüeso, Pablo; Heur, Martin; Nagel, Barbara A.; Kolar, Grant R.; Gleave, Martin E.; Nakamura, Takahiro; Kinoshita, Shigeru; Moradian-Oldak, Janet; Panjwani, Noorjahan; Pflugfelder, Stephen C.; Wilson, Mark R.; Fini, M. Elizabeth; Jeong, Shinwu

    2015-01-01

    Dry eye is a common disorder caused by inadequate hydration of the ocular surface that results in disruption of barrier function. The homeostatic protein clusterin (CLU) is prominent at fluid-tissue interfaces throughout the body. CLU levels are reduced at the ocular surface in human inflammatory disorders that manifest as severe dry eye, as well as in a preclinical mouse model for desiccating stress that mimics dry eye. Using this mouse model, we show here that CLU prevents and ameliorates ocular surface barrier disruption by a remarkable sealing mechanism dependent on attainment of a critical all-or-none concentration. When the CLU level drops below the critical all-or-none threshold, the barrier becomes vulnerable to desiccating stress. CLU binds selectively to the ocular surface subjected to desiccating stress in vivo, and in vitro to the galectin LGALS3, a key barrier component. Positioned in this way, CLU not only physically seals the ocular surface barrier, but it also protects the barrier cells and prevents further damage to barrier structure. These findings define a fundamentally new mechanism for ocular surface protection and suggest CLU as a biotherapeutic for dry eye. PMID:26402857

  16. The role of nitric oxide in ocular surface cells.

    PubMed Central

    Kim, Jae Chan; Park, Gun Sic; Kim, Jin Kook; Kim, Young Myeong

    2002-01-01

    The role of nitric oxide (NO) in the ocular surface remains unknown. We investigated the conditions leading to an increase of NO generation in tear and the main sources of NO in ocular surface tissue. We evaluated the dual action (cell survival or cell death) of NO depending on its amount. We measured the concentration of nitrite plus nitrate in the tears of ocular surface diseases and examined the main source of nitric oxide synthase (NOS). When cultured human corneal fibroblast were treated with NO producing donor with or without serum, the viabilities of cells was studied. We found that the main sources of NO in ocular surface tissue were corneal epithelium, fibroblast, endothelium, and inflammatory cells. Three forms of NOS (eNOS, bNOS, and iNOS) were expressed in experimentally induced inflammation. In the fibroblast culture system, the NO donor (SNAP, S-nitroso-N-acetyl-D, L-penicillamine) prevented the death of corneal fibroblast cells caused by serum deprivation in a dose dependent manner up to 500 micrometer SNAP, but a higher dose decreased cell viability. This study suggested that NO might act as a double-edged sword in ocular surface diseases depending on the degree of inflammation related with NO concentration. PMID:12068145

  17. Instrument for measuring the misalignments of ocular surfaces

    NASA Astrophysics Data System (ADS)

    Tabernero, Juan; Benito, Antonio; Nourrit, Vincent; Artal, Pablo

    2006-10-01

    A compact and robust instrument for measuring the alignment of ocular surfaces has been designed and used in living eyes. It is based on recording Purkinje images (reflections of light at the ocular surfaces) at nine different angular fixations. A complete analysis on the causes of misalignments of Purkinje images and its relations with those physical variables to be measured (global eye tilt, lens decentration and lens tilt) is presented. A research prototype based on these ideas was built and tested in normal and pseudophakic eyes (after cataract surgery). The new analysis techniques, together with the semicircular extended source and multiple fixation tests that we used, are significant improvements towards a robust approach to measuring the misalignments of the ocular surfaces in vivo. This instrument will be of use in both basic studies of the eye’s optics and clinical ophthalmology.

  18. Ultrasonic in vivo measurement of ocular surface expansion.

    PubMed

    Kowalska, Malgorzata A; Kasprzak, Henryk T; Iskander, D Robert; Danielewska, Monika; Mas, David

    2011-03-01

    Our aim was to ascertain whether the ultrasonic measurement of longitudinal corneal apex displacements carried out in a proper headrest is a credible method of ocular pulse (OP) detection. To distinguish between longitudinal movements of the eye globe treated as a rigid body and ocular surface expansion caused by the variations of the eye-globe volume, two ultrasound distance sensors were applied to noninvasively measure displacements of cornea and sclera. The same sensors were used to examine the influence of the anterio-posterior movements of a fixed head on the registration of corneal apex pulsation. In both experiments, ECG signals were synchronically recorded. Time, spectral, and coherence analyses obtained for four healthy subjects showed that the ocular surface expansion due to pulsatile ocular blood flow (POBF) is the main component of longitudinal corneal displacement. Ocular surface pulsation is always affected by the head movement. However, there exist some unique properties of signals, which help to distinguish between head and eye movements. A rigid headrest and a bite bar are required to stabilize the head during OP measurement. Ultrasonic technique enables noninvasive and accurate in vivo measurement of corneal pulsation, which could be of interest for indirectly estimating intraocular pressure propagation and POBF component.

  19. Ocular surface changes in glaucoma patients related to topical medications.

    PubMed

    Kovačević, Suzana; Čanović, Samir; Pavičić, Ana Didović; Kolega, Marija Škara; Bašić, Jadranka Katušić

    2015-03-01

    Topical glaucoma therapy is a long termed, usually lifelong. Antiglaucomatous drugs have toxic effects on ocular surface, due to preservative toxicitiy or the drug itself. Adding a lubricant eyedrops to antiglaucomatous therapy, especially if considering the preservative used, can have protective effect. The purpose of this study was to evaluate the stabilty of precorneal tear film in glaucoma patient prior and after administration of lubricant eye drops with different tipe of preservatives. The study showed the protective role of ocular surface lubrication especially when using drugs with less harmful preservatives.

  20. [Toxicity research status of benzalkonium chloride on ocular surface].

    PubMed

    Huang, Caihong; Chen, Wensheng; Chen, Yongxiong; Liu, Zuguo

    2014-04-01

    Benzalkonium chloride (BAC) is the most commonly used preservative in ophthalmic preparations.So far large bodies of clinical and experimental studies have shown that use of topical drugs containing BAC can induce a series of ocular surface diseases, such as apoptosis.However, recently, some clinical studies have shown that ocular toxicity in patients treated with eye drops containing BAC has not apparent correlated with BAC.Some scholars consider that the limitations of the research lead people to recognize the BAC toxicity exaggeratedly.Here we summarize numerous clinical and experimental studies of BAC in the past few years, and focus on reviewing recent researches of the toxic effect of BAC on ocular surface.

  1. Ocular surface bacterial colonisation in sedated intensive care unit patients.

    PubMed

    Mela, E K; Drimtzias, E G; Christofidou, M K; Filos, K S; Anastassiou, E D; Gartaganis, S P

    2010-01-01

    We investigated the time-dependent ocular surface bacterial colonisation of sedated patients hospitalised in an intensive care unit and aimed to evaluate whether proper topical antibiotic prophylaxis could prohibit corneal infection. The study lasted 12 months and included 134 patients undergoing sedation and mechanical respiratory support for various medical reasons. Patients hospitalised for less than seven days and those with pre-existing ocular surface pathology were excluded. All patients were examined on admission by inspecting the cornea for erosions. Followup examinations were performed each subsequent day. Cultures were also obtained from the conjunctival sac of both eyes on admission and every seventh day until the end of sedation. Standard laboratory techniques were used for isolation, identification and antibiotic susceptibility testing of bacteria. Antibiotic treatment for prophylaxis was administered accordingly. Analysis was carried out for 70 patients. Duration of sedation ranged from seven to 122 days. Fifty-four (77%) patients were colonised by at least one bacterial species other than normal flora within seven to 42 days. Multiple bacteria were isolated from 28 patients undergoing prolonged sedation. Prevalent isolates were Pseudomonas aeruginosa, Acinetobacter spp. and Staphylococcus epidermidis. Infectious keratitis was prohibited in all cases. Ocular surface of long-term sedated patients was found to be colonised by various bacterial species and their isolation was closely associated with the time period of hospitalisation. The results of this study suggest that the early identification of ocular surface bacteria colonisation and the administration of topical antibiotics for prophylaxis can prohibit corneal infection in these patients.

  2. Defensins and Other Antimicrobial Peptides at the Ocular Surface

    PubMed Central

    McDermott, Alison M.

    2006-01-01

    Although constantly exposed to the environment and “foreign bodies” such as contact lenses and unwashed fingertips, the ocular surface succumbs to infection relatively infrequently. This is, in large part, due to a very active and robust innate immune response mounted at the ocular surface. Studies over the past 20 years have revealed that small peptides with antimicrobial activity are a major component of the human innate immune response system. The ocular surface is no exception, with peptides of the defensin and cathelicidin families being detected in the tear film and secreted by corneal and conjunctival epithelial cells. There is also much evidence to suggest that the role of some antimicrobial peptides is not restricted to direct killing of pathogens, but, rather, that they function in various aspects of the immune response, including recruitment of immune cells, and through actions on dendritic cells provide a link to adaptive immunity. A role in wound healing is also supported. In this article, the properties, mechanisms of actions and functional roles of antimicrobial peptides are reviewed, with particular emphasis on the potential multifunctional roles of defensins and LL-37 (the only known human cathelicidin) at the ocular surface. PMID:17216098

  3. Infrared thermography on ocular surface temperature: A review

    NASA Astrophysics Data System (ADS)

    Tan, Jen-Hong; Ng, E. Y. K.; Rajendra Acharya, U.; Chee, C.

    2009-07-01

    Body temperature is a good indicator of human health. Thermal imaging system (thermography) is a non-invasive imaging procedure used to record the thermal patterns using Infrared (IR) camera. It provides visual and qualitative documentation of temperature changes in the vascular tissues, and is beginning to play an important role in the field of ophthalmology. This paper deals with the working principle, use and advantages of IR thermography in the field of ophthalmology. Different algorithms to acquire the ocular surface temperature (OST), that can be used for the diagnosis of ocular diseases are discussed.

  4. Ocular surface temperature in age-related macular degeneration.

    PubMed

    Sodi, Andrea; Matteoli, Sara; Giacomelli, Giovanni; Finocchio, Lucia; Corvi, Andrea; Menchini, Ugo

    2014-01-01

    Background. The aim of this study is to investigate the ocular thermographic profiles in age-related macular degeneration (AMD) eyes and age-matched controls to detect possible hemodynamic abnormalities, which could be involved in the pathogenesis of the disease. Methods. 32 eyes with early AMD, 37 eyes with atrophic AMD, 30 eyes affected by untreated neovascular AMD, and 43 eyes with fibrotic AMD were included. The control group consisted of 44 healthy eyes. Exclusion criteria were represented by any other ocular diseases other than AMD, tear film abnormalities, systemic cardiovascular abnormalities, diabetes mellitus, and a body temperature higher than 37.5°C. A total of 186 eyes without pupil dilation were investigated by infrared thermography (FLIR A320). The ocular surface temperature (OST) of three ocular points was calculated by means of an image processing technique from the infrared images. Two-sample t-test and one-way analysis of variance (ANOVA) test were used for statistical analyses. Results. ANOVA analyses showed no significant differences among AMD groups (P value >0.272). OST in AMD patients was significantly lower than in controls (P > 0.05). Conclusions. Considering the possible relationship between ocular blood flow and OST, these findings might support the central role of ischemia in the pathogenesis of AMD.

  5. Science and Art of Cell-Based Ocular Surface Regeneration.

    PubMed

    Singh, Vivek; Shukla, Sachin; Ramachandran, Charanya; Mishra, Dilip Kumar; Katikireddy, Kishore R; Lal, Ikeda; Chauhan, Sunil K; Sangwan, Virender S

    2015-01-01

    The potential cause of blindness worldwide includes diseases of the cornea, ocular surface (limbal stem cell deficiency, allergic conjunctivitis, dry eye diseases), and retinal diseases. The presence of stem cells (limbal stem cells) in the basal region of the limbus makes it an important tool for the ocular regeneration and also in maintaining the transparency of eye by replacing the corneal epithelium continuously. Various surgical modalities have been developed like cultured limbal epithelial transplantation, cultured oral mucosal epithelial transplantation, simple limbal epithelial transplantation, etc., utilizing the cell-based regenerative properties to treat limbal disorder. Cell-based therapies for ocular repair and regeneration comprise a major hope by therapies involving the mesenchymal stem cells, embryonic stem cells, and limbal stem cells for the restoration of vision in individuals whose ocular tissue has been irreversibly damaged by disease or trauma. This review explores critical needs in human disease mainly the ocular problem where cell-based therapeutics is exceptionally well suited and also the use of animal models, various artificial scaffolds, as well as advancement in clinical technique to challenge the current demand to overcome corneal blindness.

  6. Ocular Surface Temperature in Age-Related Macular Degeneration

    PubMed Central

    Sodi, Andrea; Giacomelli, Giovanni; Corvi, Andrea; Menchini, Ugo

    2014-01-01

    Background. The aim of this study is to investigate the ocular thermographic profiles in age-related macular degeneration (AMD) eyes and age-matched controls to detect possible hemodynamic abnormalities, which could be involved in the pathogenesis of the disease. Methods. 32 eyes with early AMD, 37 eyes with atrophic AMD, 30 eyes affected by untreated neovascular AMD, and 43 eyes with fibrotic AMD were included. The control group consisted of 44 healthy eyes. Exclusion criteria were represented by any other ocular diseases other than AMD, tear film abnormalities, systemic cardiovascular abnormalities, diabetes mellitus, and a body temperature higher than 37.5°C. A total of 186 eyes without pupil dilation were investigated by infrared thermography (FLIR A320). The ocular surface temperature (OST) of three ocular points was calculated by means of an image processing technique from the infrared images. Two-sample t-test and one-way analysis of variance (ANOVA) test were used for statistical analyses. Results. ANOVA analyses showed no significant differences among AMD groups (P value >0.272). OST in AMD patients was significantly lower than in controls (P > 0.05). Conclusions. Considering the possible relationship between ocular blood flow and OST, these findings might support the central role of ischemia in the pathogenesis of AMD. PMID:25436140

  7. The Impact of Visual Guided Order Picking on Ocular Comfort, Ocular Surface and Tear Function

    PubMed Central

    Klein-Theyer, Angelika; Horwath-Winter, Jutta; Rabensteiner, Dieter Franz; Schwantzer, Gerold; Wultsch, Georg; Aminfar, Haleh; Heidinger, Andrea; Boldin, Ingrid

    2016-01-01

    Purpose We investigated the effects of a visual picking system on ocular comfort, the ocular surface and tear function compared to those of a voice guided picking solution. Design Prospective, observational, cohort study. Method Setting: Institutional. Study Population: A total of 25 young asymptomatic volunteers performed commissioning over 10 hours on two consecutive days. Main Outcome Measures: The operators were guided in the picking process by two different picking solutions, either visually or by voice while their subjective symptoms and ocular surface and tear function parameters were recorded. Results The visual analogue scale (VAS) values, according to subjective dry eye symptoms, in the visual condition were significantly higher at the end of the commissioning than the baseline measurements. In the voice condition, the VAS values remained stable during the commissioning. The tear break-up time (BUT) values declined significantly in the visual condition (pre-task: 16.6 sec and post-task: 9.6 sec) in the right eyes, that were exposed to the displays, the left eyes in the visual condition showed only a minor decline, whereas the BUT values in the voice condition remained constant (right eyes) or even increased (left eyes) over the time. No significant differences in the tear meniscus height values before and after the commissioning were observed in either condition. Conclusion In our study, the use of visually guided picking solutions was correlated with post-task subjective symptoms and tear film instability. PMID:27314855

  8. Peptide therapeutics for treating ocular surface infections.

    PubMed

    Brandt, Curtis R

    2014-11-01

    Microbial pathogens-bacteria, viruses, fungi, and parasites-are significant causes of blindness, particularly in developing countries. For bacterial and some viral infections a number of antimicrobial drugs are available for therapy but there are fewer available for use in treating fungal and parasitic keratitis. There are also problems with current antimicrobials, such as limited efficacy and the presence of drug-resistant microbes. Thus, there is a need to develop additional drugs. Nature has given us an example of 1 potential source of new antimicrobials: antimicrobial peptides and proteins that are either present in bodily fluids and tissues constitutively or are induced upon infection. Given the nature of peptides, topical applications are the most likely use to be successful and this is ideal for treating keratitis. Such peptides would also be active against drug-resistant pathogens and might act synergistically if used in combination therapy. Hundreds of peptides with antimicrobial properties have been isolated or synthesized but only a handful have been tested against ocular pathogens and even fewer have been tested in animal models. This review summarizes the currently available information on the use of peptides to treat keratitis, outlines some of the problems that have been identified, and discusses future studies that will be needed. Most of the peptides that have been tested have shown activity at concentrations that do not warrant further development, but 1 or 2 have promising activity raising the possibility that peptides can be developed to treat keratitis.

  9. Peptide Therapeutics for Treating Ocular Surface Infections

    PubMed Central

    2014-01-01

    Abstract Microbial pathogens—bacteria, viruses, fungi, and parasites—are significant causes of blindness, particularly in developing countries. For bacterial and some viral infections a number of antimicrobial drugs are available for therapy but there are fewer available for use in treating fungal and parasitic keratitis. There are also problems with current antimicrobials, such as limited efficacy and the presence of drug-resistant microbes. Thus, there is a need to develop additional drugs. Nature has given us an example of 1 potential source of new antimicrobials: antimicrobial peptides and proteins that are either present in bodily fluids and tissues constitutively or are induced upon infection. Given the nature of peptides, topical applications are the most likely use to be successful and this is ideal for treating keratitis. Such peptides would also be active against drug-resistant pathogens and might act synergistically if used in combination therapy. Hundreds of peptides with antimicrobial properties have been isolated or synthesized but only a handful have been tested against ocular pathogens and even fewer have been tested in animal models. This review summarizes the currently available information on the use of peptides to treat keratitis, outlines some of the problems that have been identified, and discusses future studies that will be needed. Most of the peptides that have been tested have shown activity at concentrations that do not warrant further development, but 1 or 2 have promising activity raising the possibility that peptides can be developed to treat keratitis. PMID:25250986

  10. Observation of Influence of Cataract Surgery on the Ocular Surface

    PubMed Central

    Park, Yuli; Hwang, Hyung Bin; Kim, Hyun Seung

    2016-01-01

    Introduction To evaluate meibomian gland function, changes of lacrimal tears and ocular surface parameters and tear inflammatory mediators following cataract surgery. Methods 48 eyes of 34 patients who underwent uncomplicated phacoemulsification were involved and divided into 2 groups with those who had preexisting dry-eye before cataract surgery and those who did not. Ocular symptom score, Schirmer I test, tear film break-up time (TBUT), corneal sensitivity threshold, corneal staining, inflammatory cytokine activities, lid margin abnormalities, meibum expressibility, meibum quality and meibomian gland imaging were evaluated preoperatively, at 1 day, 1 and 2 months postoperatively. Results Ocular symptom scores were worse at 1 and 2 months postoperatively but, TBUT, corneal staining score and corneal sensitivity threshold showed gradual improvements at 1 month and 2 months postoperatively (p<0.05, respectively). Interestingly there were statistically significant improvements in TBUT, corneal staining score and corneal sensitivity threshold at 1 month postoperatively when topical eye drops were used compared to the period without topical therapy which is the months 2 postoperatively. There were statistically significant decreases in IL-1β, IL-6, IL-8, MCP-1, TNF-α and IFN-γ concentrations at 1 and 2 months postoperatively. Lid margin abnormalities, meibum quality and expressibility scores increased significantly (p < 0.05, respectively) at postoperative period. Compared with the no dry eye group, dry eye group revealed significantly higher ocular symptom scores, lower TBUT, higher lid margin abnormalities, meibum quality and expressibility scores after cataract surgery. There were significant correlations between IL-6 and parameters of dry eye, and between MGD parameters and ocular symptom scores. Conclusions Our study revealed that meibomian gland function is influenced after cataract surgery accompanying structural changes and these were correlated with

  11. Ocular surface reconstruction by cultivated epithelial sheet transplantation.

    PubMed

    Satake, Yoshiyuki; Yamaguchi, Takefumi; Hirayama, Masatoshi; Higa, Kazunari; Shimazaki-Den, Seika; Dogru, Murat; Kawakita, Tetsuya; Kawashima, Motoko; Shimmura, Shigeto; Tsubota, Kazuo; Shimazaki, Jun

    2014-11-01

    Recent advances in ocular surface reconstruction for patients with severe ocular surface diseases have significantly improved the prognosis of patients with vision-impairing corneal abnormalities. The history of cultivated epithelial sheet transplantation is short, and debate on the current approaches for these procedures is continuing. Limbal stem cell transplantation, including conjunctivolimbal autograft and keratolimbal allograft, has brought opportunities for vision improvement. In addition, the use of cultivated limbal epithelial transplantation from both allogeneic and autologous sources has provided further options for immediate postoperative epithelialization of the corneal surface. Finally, cultivated oral mucosal epithelial transplantation, which allows autologous transplantation for patients with bilateral limbal stem cell deficiency, has provided the best overall midterm and long-term results. Its biggest advantages are the absence of rejection reactions and the reduction of postoperative complications associated with steroid therapy. However, a solitary surgical approach is not sufficient for obtaining a good clinical outcome. To maximize the possibility of success using these procedures, it is important to preoperatively enhance aggressive treatment of the ocular surface, especially with factors that facilitate moisture retention. In this review article, we also discuss our clinical experience in relation to these surgical procedures.

  12. Predatory bacteria are nontoxic to the rabbit ocular surface

    PubMed Central

    Romanowski, Eric G.; Stella, Nicholas A.; Brothers, Kimberly M.; Yates, Kathleen A.; Funderburgh, Martha L.; Funderburgh, James L.; Gupta, Shilpi; Dharani, Sonal; Kadouri, Daniel E.; Shanks, Robert M. Q.

    2016-01-01

    Given the increasing emergence of antimicrobial resistant microbes and the near absent development of new antibiotic classes, innovative new therapeutic approaches to address this global problem are necessary. The use of predatory bacteria, bacteria that prey upon other bacteria, is gaining interest as an “out of the box” therapeutic treatment for multidrug resistant pathogenic bacterial infections. Before a new antimicrobial agent is used to treat infections, it must be tested for safety. The goal of this study was to test the tolerability of bacteria on the ocular surface using in vitro and in vivo models. Predatory bacteria Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus were found to be non-toxic to human corneal stromal keratocytes in vitro; however, they did induce production of the proinflammatory chemokine IL-8 but not IL-1β. Predatory bacteria did not induce inflammation on the ocular surface of rabbit eyes, with and without corneal epithelial abrasions. Unlike a standard of care antibiotic vancomycin, predatory bacteria did not inhibit corneal epithelial wound healing or increase clinical inflammatory signs in vivo. Together these data support the safety of predatory bacteria on the ocular surface, but future studies are warranted regarding the use predatory bacteria in deeper tissues of the eye. PMID:27527833

  13. Multimodal imaging of ocular surface of dry eye subjects

    NASA Astrophysics Data System (ADS)

    Zhang, Aizhong; Salahura, Gheorghe; Kottaiyan, Ranjini; Yoon, Geunyoung; Aquavella, James V.; Zavislan, James M.

    2016-03-01

    To study the relationship between the corneal lipid layer and the ocular surface temperature (OST), we conducted a clinical trial for 20 subjects. Subjects were clinically screened prior to the trial. Of the 20 subjects, 15 have Meibomian gland dysfunction (MGD), and 5 have aqueous-deficient dry eye (ADDE). A custom, circularly polarized illumination video tearscope measured the lipid layer thickness of the ocular tear film. A long-wave infrared video camera recorded the dynamic thermal properties of the ocular team film. The results of these two methods were analyzed and compared. Using principal component analysis (PCA) of the lipid layer distribution, we find that the 20 subjects could be categorized into five statistically significant groups, independent of their original clinical classification: thin (6 subjects), medium (5 subjects), medium and homogenous (3 subjects), thick (4 subjects), and very thick (2 subjects) lipids, respectively. We also conducted PCA of the OST data, and recategorized the subjects into two thermal groups by k-means clustering: one includes all ADDE subjects and some MGD subjects; the other includes the remaining MGD subjects. By comparing these two methods, we find that dry eye subjects with thin (<= 40 nm) lipids have significantly lower OST, and a larger OST drop range, potentially due to more evaporation. However, as long as the lipid layer is not thin (> 40 nm), there is no strong correlation between the lipid layer thickness and heterogeneity and the OST patterns.

  14. Current progress and challenges in ocular surface reconstruction using cultivated epithelial sheet transplantation.

    PubMed

    Inatomi, T; Nakamura, T; Koizumi, N; Sotozono, C; Kinoshita, S

    2008-07-01

    The cultivated epithelial transplantation is a new surgical modality for treating a variety of severe ocular surface disorders. This type of tissue-engineered epithelial sheet provides a rapid epithelial coverage on the corneal surface that reduces inflammation and postoperative complications. Although cultivated corneal epithelial transplantation is an effective surgical strategy, autologous transplantation is limited to unilateral cases. Autologous cultivated oral mucosal epithelial transplantation (COMET) enables surgeons to reconstruct the ocular surface using autologous, non-ocular surface cells, and has opened a new pathway for treating severe, bilateral ocular surface disorders.

  15. Invasive Ocular Surface Squamous Neoplasia Masquerading as Nodular Scleritis.

    PubMed

    Sharma, Medha; Sundar, Dheepak; Vanathi, Murugesan; Meel, Rachna; Kashyap, Seema; Chawla, Rohan; Tandon, Radhika

    The authors report a rare case of ocular surface squamous neoplasia with intraocular involvement that had an initial masquerade presentation of recurrent anterior nodular scleritis. A 35-year-old male patient presented with right eye recurrent anterior nodular scleritis for which a lamellar patch graft was done. Two months later, the patient presented with recurrence of symptoms. Histopathology review revealed the presence of well-differentiated squamous cell malignancy. A high index of suspicion for malignancy is required in such cases when they do not respond to conventional therapy.

  16. Effects of smoking on tear film and ocular surface.

    PubMed

    Yoon, Kyung-Chul; Song, Byoung-Yong; Seo, Man-Seong

    2005-03-01

    This study was performed to evaluate the changes of tear film and ocular surface caused by smoking. Symptom scoring, tear film break-up time (BUT), basal tear secretion test, corneal sensitivity test, keratoepitheliopathy scoring, and conjunctival impression cytology were performed in 29 smokers (58 eyes) and 26 non-smokers (52 eyes). Tear film BUT, basal tear secretion, corneal sensitivity, and squamous metaplasia were 7.71+/-2.66 sec, 6.29+/-2.85 mm, 53.69+/-5.69 mm, and 2.45+/-1.26 in smokers and 9.62+/-3.14 sec, 10.04+/-3.87 mm, 56.46+/-4.79 mm, and 1.12+/-0.83 in non-smokers, respectively (p<0.05). Symptom score, keratoepitheliopathy score, and goblet cell density were not significantly different between the two groups. Tear film BUT was shorter, basal tear secretion and corneal sensitivity were lower, and squamous metaplasia was higher in heavy smokers than in light smokers. In conclusion, smoking deteriorates the tear film and ocular surface with decreased quantity and quality of tear film, decreased corneal sensitivity, and squamous metaplasia, and this deterioration is related to the amount of smoking.

  17. The role of nanotechnology in control of human diseases: perspectives in ocular surface diseases.

    PubMed

    Rai, Mahendra; Ingle, Avinash P; Gaikwad, Swapnil; Padovani, Felipe Hering; Alves, Monica

    2016-10-01

    Nanotechnology is the creation and use of materials and devices on the same scale as molecules and intracellular structures, typically less than 100 nm in size. It is an emerging science and has made its way into pharmaceuticals to significantly improve the delivery and efficacy of drugs in a number of therapeutic areas, due to development of various nanoparticle-based products. In recent years, there has been increasing evidence that nanotechnology can help to overcome many of the ocular diseases and hence researchers are keenly interested in this science. Nanomedicines offer promise as viable alternatives to conventional drops, gels or ointments to improve drug delivery to the eye. Because of their small size, they are well tolerated, thus preventing washout, increase bioavailability and also help in specific drug delivery. This review describes the application of nanotechnology in the control of human diseases with special emphasis on various eye and ocular surfaces diseases.

  18. Cultured human ocular surface epithelium on therapeutic contact lenses

    PubMed Central

    Girolamo, Nick Di; Chui, Jeanie; Wakefield, Denis; Coroneo, Minas T

    2007-01-01

    Background This study was initiated after observation of some intriguing epithelial growth properties of contact lenses used as a bandage for patients after pterygium surgery. Aim To determine the efficacy of culturing human ocular surface epithelial cells on therapeutic contact lenses in autologous serum with a view of using this system to transfer epithelial cells to patients with persistent corneal or limbal defects. Methods Excess graft tissue resected from patients undergoing pterygium surgery (n = 3) consisting of limbal epithelium was placed on siloxane–hydrogel contact lenses (lotrafilcon A and balafilcon A). Limbal explants were cultured in media with 10% autologous serum. Morphology, proliferative capacity and cytokeratin profile were determined by phase contrast, light and electron microscopy, and immunohistochemical analysis. Results Lotrafilcon A contact lenses sustained proliferation and migration from limbal tissue. Cells became confluent after 10–14 days and consisted of 2–3 layers with a corneal phenotype (CK3+/CK12+/CK19−) and a propensity to proliferate (p63+). Electron microscopy showed microvilli on the apical surface with adhesive projections, indicating that these cells were stable and likely to survive for a long term. Growth was not observed from limbal explants cultured on balafilcon A contact lenses. Conclusion A method for culturing human ocular surface epithelium on contact lenses that may facilitate expansion and transfer of autologous limbal epithelial cells while avoiding the risks associated with transplanting allogeneic tissue has been developed. This technique may be potentially useful for the treatment of patients with limbal stem cell deficiency. PMID:16987897

  19. Anterior Segment Imaging in Ocular Surface Squamous Neoplasia

    PubMed Central

    Vora, Gargi K.

    2016-01-01

    Recent advances in anterior segment imaging have transformed the way ocular surface squamous neoplasia (OSSN) is diagnosed and monitored. Ultrasound biomicroscopy (UBM) has been reported to be useful primarily in the assessment of intraocular invasion and metastasis. In vivo confocal microscopy (IVCM) shows enlarged and irregular nuclei with hyperreflective cells in OSSN lesions and this has been found to correlate with histopathology findings. Anterior segment optical coherence tomography (AS-OCT) demonstrates thickened hyperreflective epithelium with an abrupt transition between abnormal and normal epithelium in OSSN lesions and this has also been shown to mimic histopathology findings. Although there are limitations to each of these imaging modalities, they can be useful adjunctive tools in the diagnosis of OSSN and could greatly assist the clinician in the management of OSSN patients. Nevertheless, anterior segment imaging has not replaced histopathology's role as the gold standard in confirming diagnosis. PMID:27800176

  20. Topical ciclosporin in the treatment of ocular surface disorders

    PubMed Central

    Tatlipinar, S; Akpek, E K

    2005-01-01

    Mounting evidence suggests that inflammation is the key factor in the pathogenesis of various ocular surface diseases, with a complex interplay of genetic, environmental, and psychosocial factors. Management of these conditions is often challenging. Topical corticosteroids, with their associated side effects, are the mainstay of current treatments for patients with vision threatening disease. Ciclosporin A is an immunomodulator that specifically inhibits T lymphocyte proliferation. Recently, a topical ciclosporin preparation was approved by the US Food and Drug Administration and became available for use in ophthalmology. Given the increasing use of ciclosporin eye drops, the goal of this article is to provide the reader with an overview of the well established uses of ciclosporin and to help refine the questions that should be addressed by future investigations. PMID:16170133

  1. Effects of Sex Hormones on Ocular Surface Epithelia: Lessons Learned From Polycystic Ovary Syndrome.

    PubMed

    Mantelli, Flavio; Moretti, Costanzo; Macchi, Ilaria; Massaro-Giordano, Giacomina; Cozzupoli, Grazia Maria; Lambiase, Alessandro; Bonini, Stefano

    2016-05-01

    Polycystic ovary syndrome (PCOS) is the most common endocrine abnormality in women of reproductive age. Although its clinical consequences have been known for a long time to extend beyond the reproductive system, with type-2 diabetes and obesity being the most common, the involvement of the ocular surface in PCOS has been described only more recently. The ocular surface is a morphofunctional unit comprising eyelid margin, tear film, cornea, and conjunctiva. Increasing evidence indicates that these structures are under a sex hormone control and relevant diseases such as ocular allergy and dry eye are often caused by alterations in circulating or local steroid hormones levels. Novel treatments targeting sex hormone receptors on ocular surface epithelial cells are also being developed. In this review we aim to describe the current knowledge on the effects of sex hormones at the ocular surface, with a special focus on the effects of androgen imbalance in PCOS.

  2. Treatment of ocular surface squamous neoplasia with Mitomycin C.

    PubMed

    Gupta, A; Muecke, J

    2010-05-01

    AIM To report the outcome of treatment of non-invasive ocular surface squamous neoplasia (or conjunctival-corneal intra-epithelial neoplasia (CCIN)) where topical mitomycin C (MMC) has been used in the treatment regimen. DESIGN Prospective, non-comparative interventional case series. PARTICIPANTS 91 primary or recurrent CCIN lesions from 90 patients treated in a single ocular oncology centre over a 10.5-year period. INTERVENTION 73 cases of localised, non-invasive CCIN and eight cases of recurrent CCIN received a treatment regimen of surgical excision+/-cryotherapy, followed by two to three 1-week cycles of adjuvant topical MMC (0.04% four times a day). 10 cases of diffuse CCIN received two to three 1-week cycles of topical MMC (0.04% four times a day) as sole primary treatment. Main outcome measure Successful treatment was defined as no clinical recurrence of CCIN. RESULTS Mean follow-up of 56.8 months (range 5.8 to 119.8) and median 57.3 months, revealed no recurrences (0%) in the localised primary group, and one persistent case and two recurrences (30%) in the diffuse primary group. There was one recurrence (12.5%) in the recurrent group, but this was in the only eye with a diffuse type of recurrence. CONCLUSIONS MMC treatment following surgical excision appears to decrease the recurrence rate of localised CCIN and should be considered as adjuvant therapy in primary treatment. MMC should also be considered as adjuvant therapy in the treatment of localised recurrent disease. MMC may be used as sole therapy in more diffuse disease, but close ongoing follow-up is recommended in view of the significant risk of persistent or recurrent disease.

  3. Ocular surface reconstruction with a tissue-engineered nasal mucosal epithelial cell sheet for the treatment of severe ocular surface diseases.

    PubMed

    Kobayashi, Masakazu; Nakamura, Takahiro; Yasuda, Makoto; Hata, Yuiko; Okura, Shoki; Iwamoto, Miyu; Nagata, Maho; Fullwood, Nigel J; Koizumi, Noriko; Hisa, Yasuo; Kinoshita, Shigeru

    2015-01-01

    Severe ocular surface diseases (OSDs) with severe dry eye can be devastating and are currently some of the most challenging eye disorders to treat. To investigate the feasibility of using an autologous tissue-engineered cultivated nasal mucosal epithelial cell sheet (CNMES) for ocular surface reconstruction, we developed a novel technique for the culture of nasal mucosal epithelial cells expanded ex vivo from biopsy-derived human nasal mucosal tissues. After the protocol, the CNMESs had 4-5 layers of stratified, well-differentiated cells, and we successfully generated cultured epithelial sheets, including numerous goblet cells. Immunohistochemistry confirmed the presence of keratins 3, 4, and 13; mucins 1, 16, and 5AC; cell junction and basement membrane assembly proteins; and stem/progenitor cell marker p75 in the CNMESs. We then transplanted the CNMESs onto the ocular surfaces of rabbits and confirmed the survival of this tissue, including the goblet cells, up to 2 weeks. The present report describes an attempt to overcome the problems of treating severe OSDs with the most severe dry eye by treating them using tissue-engineered CNMESs to supply functional goblet cells and to stabilize and reconstruct the ocular surface. The present study is a first step toward assessing the use of tissue-engineered goblet-cell transplantation of nonocular surface origin for ocular surface reconstruction.

  4. Fluids of the ocular surface: concepts, functions and physics.

    PubMed

    Cher, Ivan

    2012-08-01

    General adoption of the ocular surface (OS) concept has advanced the therapy of the external eye. Fresh physical findings have prompted new concepts; examples taken from each section of the text are: (i) ever-present lipid sealant bridges the palpebral fissure capping the three-dimensional 'OS' sac. The muco-aqueous pool (MAP) is thus enclosed, secluded from atmosphere, evaporation mitigated. Hence, the OS is conceptually, a compartment. The term 'dacruon' (otherwise 'tear film') has been coined for the combined fluids of the OS, viz. lipid film and MAP. (ii) Investigative techniques of physics yield data on (say) surface tension and viscosity, and on functions such as anchorage of dacruon base to the varied mucosae of the OS, lubrication, renovation of intermarginal fluid layers as the eye opens after each blink, and refinement of optics and vision by the fluids attached to the cornea. (iii) Physical events in the opening eye produce the unique 'black line' phenomenon in which capillary force induces subsurface flows into thirsty menisci, bringing about parameniscal dark grooves, pupil-ward of each meniscus. Attenuation of fluorescein in the shallowed fluid gaps behind each groove makes the dye appear unilluminated ('black lines') relative to adjacent full-thickness MAP fluid glowing under cobalt-blue illumination. Isolated from cornea by grooves and gaps, the meniscal fluid cannot pass freely over the cornea. It therefore streams through the menisci to nasolacrimal outflow.

  5. An impression cytology based study of ocular surface in an urban population.

    PubMed

    Mukhopadhyay, Somnath; Dutta, Jayanta; Mitra, Jayati; Prakash, Ratnesh; Datta, Himadri

    2013-04-01

    To assess the health of ocular surface in a defined urban population, conjunctival goblet cell density and degree of surface squamous metaplasia were utilized as study tools. Two thousand names of those aged between 20 and 79 years from the 2006 electoral register in ward number 63 of Kolkata Corporation area were initially selected. Normal healthy human volunteers without any history of ocular surface disorder were recruited and divided into five age-groups. Impression cytology samples were obtained from interpalpebral part of bulbar conjunctiva from all the participants fixated and stained by a single observer. A stratified, clustered, disproportionate, random sampling method was used. The software used in the statistical analysis was EPI Info. The tests applied were t test and ANOVA. A variation in the number of goblet cells according to gender (women having less cells) and age (20-30 years group having the highest number of cells) was found. Those working outdoors were found to have fewer goblet cells compared to those who stay indoors. The majority of the people had grade 1 cytological appearance in both males and females. There was no statistically significant difference in Nelson's grading with age. People using coal and kerosene to cook were found to have a smaller goblet cell density than those who cooked on LPG or those who did not cook at all. Besides age and sex, environmental factors like the method of cooking and occupational variables (like outdoor activity, prolonged period of computer use, etc.) modify the health of the ocular surface. The results of this study will help put these findings into perspective as public health problems.

  6. Ocular Surface Squamous Neoplasia Associated with Atopic Keratoconjunctivitis

    PubMed Central

    Shah, Ankit; Espana, Edgar M.; Singh, Arun D.

    2017-01-01

    Purpose To describe 2 cases of invasive squamous cell carcinoma that originated in the setting of severe atopic keratoconjunctivitis (AKC). Methods Case one involved a 73-year-old male with atopic eczema and severe AKC who developed a limbal lesion suspicious for ocular surface squamous neoplasia (OSSN). Slit-lamp examination was significant for a new sessile lesion in the temporal limbal region of the left eye. The lesion was treated with excisional biopsy and cryotherapy. Topical therapy with mitomycin C, topical interferon alpha 2b, and topical 5-fluorouracil provided only partial control. Exenteration was eventually needed. Case two involved a 53-year-old male with history of severe AKC and eczema. Computed tomography imaging showed an infiltrative mass of the right orbit. Incisional biopsies confirmed conjunctival squamous cell carcinoma of both sides (invasive in the right eye, in situ in the left eye). Exenteration was needed for control of invasive carcinoma in the right eye. Results Squamous cell carcinoma was treated without success in spite of surgical excision and aggressive treatment with multiple topical agents and multiple applications of cryotherapy. Orbital exenteration was needed in both cases. Conclusion Chronic inflammation associated with AKC may be a risk factor for the development of bilateral, diffuse, invasive, and recurrent OSSN that may require exenteration. PMID:28275599

  7. Applications of Anterior Segment Optical Coherence Tomography in Cornea and Ocular Surface Diseases

    PubMed Central

    Han, Sang Beom; Liu, Yu-Chi; Noriega, Karim Mohamed

    2016-01-01

    Optical coherence tomography (OCT) is a noncontact technology that produces high-resolution cross-sectional images of ocular tissues. Anterior segment OCT (AS-OCT) enables the precise visualization of anterior segment structure; thus, it can be used in various corneal and ocular surface disorders. In this review, the authors will discuss the application of AS-OCT for diagnosis and management of various corneal and ocular surface disorders. Use of AS-OCT for anterior segment surgery and postoperative management will also be discussed. In addition, application of the device for research using human data and animal models will be introduced. PMID:27721988

  8. Mitomycin C as an adjunct in the treatment of localised ocular surface squamous neoplasia

    PubMed Central

    Chen, C; Louis, D; Dodd, T; Muecke, J

    2004-01-01

    Aim: To report the outcome of topical mitomycin C (MMC) used as adjunctive treatment following primary excision of ocular surface squamous neoplasia (OSSN). Method: Prospective, non-comparative interventional case series of 27 primary OSSN lesions from 26 patients treated in a single ocular oncology centre over a 4 year period. Result: 27 cases of OSSN received a treatment regimen of surgical excision, followed by topical MMC. Mean follow up of 27 (SD 12) months (range 12–50, median 25 months) revealed zero recurrences. Conclusion: MMC treatment following surgical excision decreases the recurrence rate of primary ocular surface neoplasia and should be considered as adjunctive therapy in primary treatment. PMID:14693762

  9. Difference in ocular surface temperature by infrared thermography in phakic and pseudophakic patients

    PubMed Central

    Sniegowski, Matthew; Erlanger, Michael; Velez-Montoya, Raul; Olson, Jeffrey L

    2015-01-01

    Purpose To assess the change in ocular surface temperature between healthy phakic and pseudophakic patients. Methods We included patients with no history of ocular disease other than cataract. Patients were divided into three groups: clear lens, cataract, and pseudophakic. All patients had two ocular surface digital thermal scans. An average of five surface points was used as the mean ocular surface temperature. Results were analyzed with a one-way analysis of variance and a Tukey’s least significance difference test. The patients were further divided into phakic and pseudophakic groups. Correlation coefficients between several variables were done in order to assess dependencies. Results Fifty-six eyes (28 cataracts, 12 clear lenses, 16 pseudophakic) were enrolled. The mean ocular surface temperature in the cataract group was 34.14°C±1.51°C; clear lens: 34.43°C±2.27°C; and pseudophakic: 34.97°C±1.57°C. There were no statistical differences among the study groups (P=0.3). There was a nonsignificant negative correlation trend between age and surface temperature in the phakic group. The trend inverted in the pseudophakic group but without statistical significance. Conclusion Although cataract extraction and intraocular lens implantation seem to induce a mild increase in ocular surface temperature, the effect is not clear and not significant. PMID:25834383

  10. Evaluation of Ocular Surface Disease in Asian Patients with Primary Angle Closure

    PubMed Central

    Ling, Tan Ee; Othman, Khairuddin; Yan, Ong Poh; Rashid, Rasdi Abdul; Tet, Cheong Min; Yaakob, Azhany; Tajudin, Liza-Sharmini Ahmad

    2017-01-01

    Objective: To evaluate the incidence of ocular surface disease (OSD) and to determine the effects of topical pressure-lowering drugs on ocular surface disease in primary angle closure patients. Methods: This was a cross-sectional comparative study comparing primary angle closure glaucoma (PACG) patients (Group A) with primary angle closure and primary angle closure suspect (Group B). Group A was treated with topical pressure-lowering drugs; Group B was not. Data on ocular diagnosis and details of treatment were obtained from medical records. Ocular surface disease incidence was assessed using the Ocular Surface Disease Index (OSDI) questionnaire and from clinical signs using Schirmer’s test, tear break-up time and corneal fluorescein stain. Predictive Analytic Software 20 and STATA analysis software were used for statistical analyses. Results: Group A demonstrated a higher rate of OSD (OSDI 52.3%, Schirmer’s test 70.5%, tear break-up time (TBUT) 75%, corneal staining 77.3%) compared to Group B (OSDI 39.0%, Schirmer’s test 73.2%, TBUT 58.5% and cornea staining 14.6%) except for Schirmer’s test. There was a significant difference in mean score of OSDI (p=0.004), TBUT (p=0.008) and cornea staining (p<0.001) between two groups. Primary angle closure glaucoma treated with more than two medications and for more than three years had worse ocular surface disease parameters but without statistical significant difference. Conclusion: Ocular surface disease is common in PACG patients treated with topical pressure-lowering drugs. Topical pressure-lowering drugs caused significant OSD symptoms and signs except for tear production in PACG patients. Thorough evaluation of ocular surface disease is important to ensure appropriate treatment and intervention in PACG patients.

  11. Interfacial Interaction between Transmembrane Ocular Mucins and Adhesive Polymers and Dendrimers Analyzed by Surface Plasmon Resonance

    PubMed Central

    Noiray, M.; Briand, E.; Woodward, A. M.; Argüeso, P.; Molina Martínez, I. T.; Herrero-Vanrell, R.; Ponchel, G.

    2013-01-01

    Purpose Development of the first in vitro method based on biosensor chip technology designed for probing the interfacial interaction phenomena between transmembrane ocular mucins and adhesive polymers and dendrimers intended for ophthalmic administration. Methods The surface plasmon resonance (SPR) technique was used. A transmembrane ocular mucin surface was prepared on the chip surface and characterized by QCM-D (Quartz Crystal Microbalance with Dissipation) and XPS (X-ray photoelectron spectroscopy). The mucoadhesive molecules tested were: hyaluronic acid (HA), carboxymethyl cellulose (CMC), hydroxypropylmethyl cellulose (HPMC), chitosan (Ch) and polyamidoamine dendrimers (PAMAM). Results While Ch originated interfacial interaction with ocular transmembrane mucins, for HA, CMC and HPMC, chain interdiffusion seemed to be mandatory for bioadherence at the concentrations used in ophthalmic clinical practise. Interestingly, PAMAM dendrimers developed permanent interfacial interactions with transmembrane ocular mucins whatever their surface chemical groups, showing a relevant importance of co-operative effect of these multivalent systems. Polymers developed interfacial interactions with ocular membrane-associated mucins in the following order: Ch(1 %) > G4PAMAM-NH2(2 %) = G4PAMAM-OH(2 %) > G3.5PAMAM-COOH(2 %)≫ CMC(0.5 %) = HA(0.2 %) = HPMC(0.3 %). Conclusions The method proposed is useful to discern between the mucin-polymer chemical interactions at molecular scale. Results reinforce the usefulness of chitosan and den-drimers as polymers able to increase the retention time of drugs on the ocular surface and hence their bioavailability. PMID:22565639

  12. OCT-based profiler for automating ocular surface prosthetic fitting (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Mujat, Mircea; Patel, Ankit H.; Maguluri, Gopi N.; Iftimia, Nicusor V.; Patel, Chirag; Agranat, Josh; Tomashevskaya, Olga; Bonte, Eugene; Ferguson, R. Daniel

    2016-03-01

    The use of a Prosthetic Replacement of the Ocular Surface Environment (PROSE) device is a revolutionary treatment for military patients that have lost their eyelids due to 3rd degree facial burns and for civilians who suffer from a host of corneal diseases. However, custom manual fitting is often a protracted painful, inexact process that requires multiple fitting sessions. Training for new practitioners is a long process. Automated methods to measure the complete corneal and scleral topology would provide a valuable tool for both clinicians and PROSE device manufacturers and would help streamline the fitting process. PSI has developed an ocular anterior-segment profiler based on Optical Coherence Tomography (OCT), which provides a 3D measure of the surface of the sclera and cornea. This device will provide topography data that will be used to expedite and improve the fabrication process for PROSE devices. OCT has been used to image portions of the cornea and sclera and to measure surface topology for smaller contact lenses [1-3]. However, current state-of-the-art anterior eye OCT systems can only scan about 16 mm of the eye's anterior surface, which is not sufficient for covering the sclera around the cornea. In addition, there is no systematic method for scanning and aligning/stitching the full scleral/corneal surface and commercial segmentation software is not optimized for the PROSE application. Although preliminary, our results demonstrate the capability of PSI's approach to generate accurate surface plots over relatively large areas of the eye, which is not currently possible with any other existing platform. Testing the technology on human volunteers is currently underway at Boston Foundation for Sight.

  13. Clinical Presentation of Ocular Surface Squamous Neoplasia in Kenya

    PubMed Central

    Gichuhi, Stephen; Macharia, Ephantus; Kabiru, Joy; Zindamoyen, Alain M’bongo; Rono, Hilary; Ollando, Ernest; Wanyonyi, Leonard; Wachira, Joseph; Munene, Rhoda; Onyuma, Timothy; Sagoo, Mandeep S.; Weiss, Helen A.; Burton, Matthew J.

    2017-01-01

    Importance There is a trend towards treating conjunctival lesions suspected to be ocular surface squamous neoplasia (OSSN) based on the clinical impression. Objectives To describe the presentation of OSSN and identify clinical features which distinguish it from benign lesions and subsequently evaluate their recognisability. Design, Setting and Participants Prospective multi-centre study in Kenya from July 2012 through July 2014 of 496 adults presenting with conjunctival lesions. Exposures Comprehensive history, slit lamp examination and photography before excision biopsy. Frequency of clinical features in OSSN and benign lesions recorded. One histopathologist examined all specimens. Six additional masked ophthalmologists independently examined photographs from 100 participants and assessed clinical features. Main Outcomes and Measures Proportions and means were compared using Chi-square, Fisher’s exact test or t-test as appropriate. Inter-observer agreement was estimated using Kappa statistic. Examiners’ assessments were compared to a reference. Results Among 496 participants, OSSN was the most common (38%) histological diagnosis, followed by pterygium (36%) and actinic keratosis (19%). OSSN cases were slightly older and tended to have lower levels of education than benign ones. Females predominated (67% of OSSN vs 64% of benign lesions; P = .65). HIV-infection was common among OSSN cases (74%). The commonest location was the nasal limbus (61% OSSN vs 78% benign lesions; P < .001). Signs more frequent in OSSN included; feeder vessels, odds ratio [OR], 5.8 [95%CI, 3.2-10.5]; moderate inflammation, OR, 3.5 [95%CI,1.8-6.8]; corneal involvement, OR, 2.7 [95%CI,1.8-4.0]; leukoplakia, OR, 2.6 [95%CI,1.7-3.9]; papilliform surface, OR, 2.1 [95%CI,1.3-3.5]; pigmentation, OR, 1.5 [95%CI, 1.0-2.2]; temporal location, OR, 2.0 [95%cI, 1.2-3.2]; circumlimbal location, (7.0% vs 0.3%; P<.001); severe inflammation (6.0% vs 0.3%; P <.001) and larger mean [SD] diameter (6.8 [3

  14. Diagnosing Ocular Surface Squamous Neoplasia in East Africa

    PubMed Central

    Nguena, Marie B.; van den Tweel, Jan G.; Makupa, William; Hu, Victor H.; Weiss, Helen A.; Gichuhi, Stephen; Burton, Matthew J.

    2014-01-01

    Objective To examine the reliability of clinical examination and in vivo confocal microscopy (IVCM) in distinguishing ocular surface squamous neoplasia (OSSN) from benign conjunctival lesions. Design Case-control study. Participants Sixty individuals with conjunctival lesions (OSSN and benign) and 60 age-matched controls with normal conjunctiva presenting to Kilimanjaro Christian Medical Centre, Moshi, Tanzania. Methods Participants were examined and photographed, and IVCM was performed. Patients with conjunctival lesions were offered excisional biopsy with histopathology and a human immunodeficiency virus (HIV) test. The IVCM images were read masked to the clinical appearance and pathology results. Images were graded for several specific features and given an overall categorization (normal, benign, or malignant). A group of 8 ophthalmologists were shown photographs of conjunctival lesions and asked to independently classify as OSSN or benign. Main Outcome Measures Comparison of the histopathology diagnosis with the clinical and IVCM diagnosis. Results Fifty-two cases underwent excisional biopsy with histopathology; 34 were on the OSSN spectrum, 17 were benign, and 1 was lymphoma. The cases and controls had comparable demographic profiles. Human immunodeficiency syndrome infection was more common in OSSN compared with benign cases (58.8% vs. 5.6%; odds ratio, 24.3, 95% confidence interval [CI], 2.8–204; P = 0.003). Clinically, OSSN lesions more frequently exhibited feeder vessels and tended to have more leukoplakia and a gelatinous appearance. Overall, the ophthalmologists showed moderate agreement with the histology result (average kappa = 0.51; 95% CI, 0.36–0.64). The masked grading of IVCM images reliably distinguished normal conjunctiva. However, IVCM was unable to reliably distinguish between benign lesions and OSSN because of an overlap in their appearance (kappa = 0.44; 95% CI, 0.32–0.57). No single feature was significantly more frequent in OSSN

  15. Contribution of the cornea and internal surfaces to the change of ocular aberrations with age

    NASA Astrophysics Data System (ADS)

    Artal, Pablo; Berrio, Esther; Guirao, Antonio; Piers, Patricia

    2002-01-01

    We studied the age dependence of the relative contributions of the aberrations of the cornea and the internal ocular surfaces to the total aberrations of the eye. We measured the wave-front aberration of the eye with a Hartmann-Shack sensor and the aberrations of the anterior corneal surface from the elevation data provided by a corneal topography system. The aberrations of the internal surfaces were obtained by direct subtraction of the ocular and corneal wave-front data. Measurements were obtained for normal healthy subjects with ages ranging from 20 to 70 years. The magnitude of the RMS wave-front aberration (excluding defocus and astigmatism) of the eye increases more than threefold within the age range considered. However, the aberrations of the anterior corneal surface increase only slightly with age. In most of the younger subjects, total ocular aberrations are lower than corneal aberrations, while in the older subjects the reverse condition occurs. Astigmatism, coma, and spherical aberration of the cornea are larger than in the complete eye in younger subjects, whereas the contrary is true for the older subjects. The internal ocular surfaces compensate, at least in part, for the aberrations associated with the cornea in most younger subjects, but this compensation is not present in the older subjects. These results suggest that the degradation of the ocular optics with age can be explained largely by the loss of the balance between the aberrations of the corneal and the internal surfaces.

  16. Ocular surface discomfort and Demodex: effect of tea tree oil eyelid scrub in Demodex blepharitis.

    PubMed

    Koo, Hyun; Kim, Tae Hyung; Kim, Kyoung Woo; Wee, Sung Wook; Chun, Yeoun Sook; Kim, Jae Chan

    2012-12-01

    The purpose of this study was to evaluate the relation between ocular discomfort and ocular Demodex infestation, and therapeutic effects of tea tree oil (TTO) in Demodex blepharitis patients. Three hundred and thirty-five patients with ocular discomfort were evaluated for ocular Demodex infestation and subjective symptoms with ocular surface discomfort index (OSDI) score. Among them, Demodex-infested patients were randomized to receive either eyelid scrubbing with TTO (TTO group,106 patients) or without TTO (Control group, 54 patients) for 1 month. Demodex were found in 84% of patients with ocular discomfort. The number of Demodex was significantly correlated with age (P = 0.04) and OSDI score (P = 0.024). After eyelid scrub treatment, Demodex count was reduced from 4.0 ± 2.5 to 3.2 ± 2.3 in the TTO group (P = 0.004) and from 4.3 ± 2.7 to 4.2 ± 2.5 in the control group (P = 0.27). Also, OSDI score was reduced from 34.5 ± 10.7 to 24.1 ± 11.9 in the TTO group (P = 0.001) and from 35.3 ± 11.6 to 27.5 ± 12.8 in the control group (P = 0.04). In conclusion, Demodex number showed a significant positive correlation with age and subjective ocular discomfort. The tea tree oil eyelid scrub treatment is effective for eliminating ocular Demodex and improving subjective ocular symptoms.

  17. Ocular Surface Discomfort and Demodex: Effect of Tea Tree Oil Eyelid Scrub in Demodex Blepharitis

    PubMed Central

    Koo, Hyun; Kim, Tae Hyung; Kim, Kyoung Woo; Wee, Sung Wook; Chun, Yeoun Sook

    2012-01-01

    The purpose of this study was to evaluate the relation between ocular discomfort and ocular Demodex infestation, and therapeutic effects of tea tree oil (TTO) in Demodex blepharitis patients. Three hundred and thirty-five patients with ocular discomfort were evaluated for ocular Demodex infestation and subjective symptoms with ocular surface discomfort index (OSDI) score. Among them, Demodex-infested patients were randomized to receive either eyelid scrubbing with TTO (TTO group,106 patients) or without TTO (Control group, 54 patients) for 1 month. Demodex were found in 84% of patients with ocular discomfort. The number of Demodex was significantly correlated with age (P = 0.04) and OSDI score (P = 0.024). After eyelid scrub treatment, Demodex count was reduced from 4.0 ± 2.5 to 3.2 ± 2.3 in the TTO group (P = 0.004) and from 4.3 ± 2.7 to 4.2 ± 2.5 in the control group (P = 0.27). Also, OSDI score was reduced from 34.5 ± 10.7 to 24.1 ± 11.9 in the TTO group (P = 0.001) and from 35.3 ± 11.6 to 27.5 ± 12.8 in the control group (P = 0.04). In conclusion, Demodex number showed a significant positive correlation with age and subjective ocular discomfort. The tea tree oil eyelid scrub treatment is effective for eliminating ocular Demodex and improving subjective ocular symptoms. PMID:23255861

  18. Desiccating stress-induced disruption of ocular surface immune tolerance drives dry eye disease.

    PubMed

    Guzmán, M; Keitelman, I; Sabbione, F; Trevani, A S; Giordano, M N; Galletti, J G

    2016-05-01

    Dry eye is an allegedly autoimmune disorder for which the initiating mechanisms and the targeted antigens in the ocular surface are not known, yet there is extensive evidence that a localized T helper type 1 (Th1)/Th17 effector T cell response is responsible for its pathogenesis. In this work, we explore the reconciling hypothesis that desiccating stress, which is usually considered an exacerbating factor, could actually be sufficient to skew the ocular surface's mucosal response to any antigen and therefore drive the disease. Using a mouse model of dry eye, we found that desiccating stress causes a nuclear factor kappa B (NF-κB)- and time-dependent disruption of the ocular surface's immune tolerance to exogenous ovalbumin. This pathogenic event is mediated by increased Th1 and Th17 T cells and reduced regulatory T cells in the draining lymph nodes. Conversely, topical NF-κB inhibitors reduced corneal epithelial damage and interleukin (IL)-1β and IL-6 levels in the ocular surface of mice under desiccating stress. The observed effect was mediated by an augmented regulatory T cell response, a finding that highlights the role of mucosal tolerance disruption in dry eye pathogenesis. Remarkably, the NF-κB pathway is also involved in mucosal tolerance disruption in other ocular surface disorders. Together, these results suggest that targeting of mucosal NF-κB activation could have therapeutic potential in dry eye.

  19. Ocular surface mucins and local inflammation--studies in genetically modified mouse lines.

    PubMed

    Shirai, Kumi; Saika, Shizuya

    2015-12-17

    Mucins locate to the apical surfaces of all wet-surfaced epithelia including ocular surface. The functions of the mucins include anti-adhesive, lubrication, water retention, allergens and pathogen barrier function. Ocular surface pathologies, i.e. dry eye syndrome or allergic conjunctivitis, are reportedly associated with alteration of expression pattern of mucin components. Recent investigations indicated anti-bacterial adhesion or anti-inflammatory effects of members of mucins in non-ocular tissues, i.e., gastrointestinal tracts or airway tissues, by using genetically modified mouse lines that lacks an expression of a mucin member. However, examination of ocular phenotypes of each of mucin gene-ablated mouse lines has not yet fully performed. Muc16-deficient mouse is associated with spontaneous subclinical inflammation in conjunctiva. The article reviews the roles of mucin members in modulation of local inflammation in mucous membrane tissues and phenotype of mouse lines with the loss of a mucin gene. Analysis of ocular surface of mucin-gene related mutant mouse lines are to be further performed.

  20. An Update on Ocular Surface Epithelial Stem Cells: Cornea and Conjunctiva.

    PubMed

    Ramos, Tiago; Scott, Deborah; Ahmad, Sajjad

    2015-01-01

    The human ocular surface (front surface of the eye) is formed by two different types of epithelia: the corneal epithelium centrally and the conjunctival epithelium that surrounds this. These two epithelia are maintained by different stem cell populations (limbal stem cells for the corneal epithelium and the conjunctival epithelial stem cells). In this review, we provide an update on our understanding of these epithelia and their stem cells systems, including embryology, new markers, and controversy around the location of these stem cells. We also provide an update on the translation of this understanding into clinical applications for the treatment of debilitating ocular surface diseases.

  1. High surface area calcite

    NASA Astrophysics Data System (ADS)

    Schultz, L. N.; Andersson, M. P.; Dalby, K. N.; Müter, D.; Okhrimenko, D. V.; Fordsmand, H.; Stipp, S. L. S.

    2013-05-01

    Calcite (CaCO3) is important in many fields—in nature, because it is a component of aquifers, oil reservoirs and prospective CO2 storage sites, and in industry, where it is used in products as diverse as paper, toothpaste, paint, plastic and aspirin. It is difficult to obtain high purity calcite with a high surface area but such material is necessary for industrial applications and for fundamental calcite research. Commercial powder is nearly always contaminated with growth inhibitors such as sugars, citrate or pectin and most laboratory synthesis methods deliver large precipitates, often containing vaterite or aragonite. To address this problem, we (i) adapted the method of carbonating a Ca(OH)2 slurry with CO2 gas to develop the first simple, cheap, safe and reproducible procedure using common laboratory equipment, to obtain calcite that reproducibly had a surface area of 14-17 m2/g and (ii) conducted a thorough characterization of the product. Scanning electron microscopy (SEM) revealed nanometer scale, rhombohedral crystals. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR) confirmed highly crystalline, pure calcite that more closely resembles the dimensions of the biogenic calcite produced by algae in coccoliths than other methods for synthesizing calcite. We suggest that this calcite is useful when purity and high surface area are important.

  2. Evaluation of topographical variation in ocular surface temperature by functional infrared thermography

    NASA Astrophysics Data System (ADS)

    Tan, Jen Hong; Ng, E. Y. K.; Acharya, U. Rajendra

    2011-11-01

    The objective of this work is to evaluate topographical variation in the ocular surface temperature (OST) among the young, elderly and the subjects wearing contact lens using thermographic methodology. We recorded thermographic sequence lasting of 25 s for each eye. The ocular region in each of the thermal images in the sequence was identified and warped into a standard form. Then, the warped sequence was divided into a number of sub-sequences. A differential image which is an image matrix was obtained from each of these sub-sequences, by subtracting thermal images within the sub-sequence. And the histogram of the differential image was modelled by Gaussian mixture model to discriminate eyelashes from the ocular surface for every thermal image in the sub-sequence. Later, thermal data of eyelashes were eliminated in every thermal image and statistical analysis was performed on the sequences. Finally, topographical profile of each subject group was approximated by equations and illustrated using various temperature profiles. The ocular surface of the young subject was observed to be the warmest, and tear film was determined to play a major role in the topographical and temporal variations in OST. Significant topographical variation was observed among subject groups. Based on our compiled average OST profile (AOSTP), the maximum predictability of the bioheat simulation on ocular model can reach up to 90%.

  3. Extended scan depth optical coherence tomography for evaluating ocular surface shape

    PubMed Central

    Shen, Meixiao; Cui, Lele; Li, Ming; Zhu, Dexi; Wang, Michael R.; Wang, Jianhua

    2011-01-01

    Spectral domain optical coherence tomography (SD-OCT) with extended scan depth makes it possible for quantitative measurement of the entire ocular surface shape. We proposed a novel method for ocular surface shape measurement using a custom-built anterior segment SD-OCT, which will serve on the contact lens fitting. A crosshair alignment system was applied to reduce the misalignment and tilting of the eye. An algorithm was developed to automatically segment the ocular surface. We also described the correction of the image distortion from the segmented dataset induced by the nontelecentric scanning system and tested the accuracy and repeatability. The results showed high accuracy of SD-OCT in measuring a bicurved test surface with a maximum height error of 17.4 μm. The repeatability of in vivo measurement was also good. The standard deviations of the height measurement within a 14-mm wide range were all less than 35 μm. This work demonstrates the feasibility of using extended depth SD-OCT to perform noninvasive evaluation of the ocular surface shape. PMID:21639575

  4. Extended scan depth optical coherence tomography for evaluating ocular surface shape

    NASA Astrophysics Data System (ADS)

    Shen, Meixiao; Cui, Lele; Li, Ming; Zhu, Dexi; Wang, Michael R.; Wang, Jianhua

    2011-05-01

    Spectral domain optical coherence tomography (SD-OCT) with extended scan depth makes it possible for quantitative measurement of the entire ocular surface shape. We proposed a novel method for ocular surface shape measurement using a custom-built anterior segment SD-OCT, which will serve on the contact lens fitting. A crosshair alignment system was applied to reduce the misalignment and tilting of the eye. An algorithm was developed to automatically segment the ocular surface. We also described the correction of the image distortion from the segmented dataset induced by the nontelecentric scanning system and tested the accuracy and repeatability. The results showed high accuracy of SD-OCT in measuring a bicurved test surface with a maximum height error of 17.4 μm. The repeatability of in vivo measurement was also good. The standard deviations of the height measurement within a 14-mm wide range were all less than 35 μm. This work demonstrates the feasibility of using extended depth SD-OCT to perform noninvasive evaluation of the ocular surface shape.

  5. [Ocular allergies].

    PubMed

    Messmer, E M

    2005-05-01

    Recent developments indicate that ocular allergy is more than an IgE-mediated allergic conjunctivitis. Ocular allergy is a disease affecting the entire ocular surface including conjunctiva, lids, cornea, lacrimal gland and tear film. Besides an IgE-mediated reaction, a complex chronic inflammation is involved in the pathogenesis of many ocular allergies. According to their pathogenesis and clinical picture, ocular allergies are classified into mild forms, such as seasonal and perennial allergic conjunctivitis as well as giant papillary conjunctivitis, and chronic, potentially blinding forms such as atopic keratoconjunctivitis and vernal keratoconjunctivitis. New therapeutics act on the entire inflammatory process or try to modulate the allergic reaction early and specifically. The association with non-ocular allergic symptoms requires an interdisciplinary approach.

  6. Complications of mitomycin C therapy in 100 eyes with ocular surface neoplasia

    PubMed Central

    Khong, J J; Muecke, J

    2006-01-01

    Aim To determine the complications associated with mitomycin C (MMC) in the treatment of ocular surface neoplasia. Methods A retrospective and consecutive study of 100 eyes in 91 patients with ocular surface neoplasia treated with MMC in a single centre between November 1998 and January 2005. Outcome measures included complications of MMC and the treatment required for these complications. Results One to three 7 day cycles of topical MMC 0.04% four times a day were given to 59 eyes with localised corneal‐conjunctival intraepithelial neoplasia (CIN), 19 eyes with diffuse CIN, six eyes with recurrent CIN, one eye with ocular surface squamous cell carcinoma, three eyes with primary acquired melanosis (PAM) with atypia, nine eyes with conjunctival malignant melanoma (MM), two eyes with sebaceous carcinoma with pagetoid spread, and one eye with recurrent atypical fibroxanthoma. Nine patients had bilateral CIN. 31 (34%) cases developed an allergic reaction to MMC and 14 (14%) eyes had epiphora secondary to punctal stenosis at a mean follow up period of 26.5 months. Conclusion In the largest study looking at complications of topical MMC in the treatment of ocular surface neoplasia, allergic reaction and punctal stenosis are relatively common. Serious complications were not observed suggesting the safe use of MMC in mid‐term follow up. PMID:16672325

  7. Xeroderma pigmentosum with bilateral ocular surface squamous neoplasia and review of the literature.

    PubMed

    Kalamkar, Charudutt; Radke, Nishant; Mukherjee, Amrita; Radke, Snehal

    2016-05-10

    Xeroderma pigmentosum is a rare genetic disorder associated with various ocular malignancies. Here we report a single paediatric case of xeroderma pigmentosum with bilateral ocular surface squamous neoplasia (OSSN) presenting with diffuse lesion in one eye and a large mass in the other eye. Diffuse OSSN in one eye was treated with topical chemotherapy using mitomycin-C (0.04%) and the large OSSN in the other eye was treated with a combination of surgery and topical chemotherapy. Long-term follow-up and a multimodality treatment approach are necessary to identify and manage recurrences of OSSN in XP.

  8. Structural asymmetry of cortical visual areas is related to ocular dominance.

    PubMed

    Jensen, Bettina H; Hougaard, Anders; Amin, Faisal M; Larsson, Henrik B W; Ashina, Messoud

    2015-12-02

    The grey matter of the human brain is asymmetrically distributed between the cerebral hemispheres. This asymmetry includes visual areas, but its relevance to visual function is not understood. Voxel-based morphometry is a well-established technique for localization and quantification of cerebral grey matter on the basis of MR images. This method has been used previously for interhemispheric comparison, but without examining the functional implications of the identified anatomical asymmetries of the visual system. The aim of the present study was to relate anatomical interhemispheric asymmetries to asymmetries of visual function. We examined grey matter asymmetries of visual areas in a large population (n=56) of ophthalmologically and neurologically healthy individuals. We used state-of-the-art 3 T MRI and voxel-based morphometry to relate the visual parameters, (a) ocular dominance, (b) interocular difference in visual acuity and (c) visual attention (i.e. deviation on a line-bisection task), to interhemispheric differences in grey matter volume. As most visual input from one eye is processed in the contralateral hemisphere, ocular features may also depend on cerebral lateralization. Several lateralized visual areas were identified, both right>left and left>right. When correlating the asymmetries to the functional parameters, we found a significant correlation to ocular dominance (P<0.05), whereas visual acuity and visual attention showed no such relationship. The lateral occipital complex was identified to be significantly larger in the left hemisphere for right-eyed participants and vice versa. These results suggest a cerebral basis for ocular dominance.

  9. Ocular Surface Symptoms in Veterans Returning From Operation Iraqi Freedom and Operation Enduring Freedom

    PubMed Central

    Modi, Yasha S.; Qurban, Qirat; Zlotcavitch, Leonid; Echeverri, Roberto J.; Feuer, William; Florez, Hermes; Galor, Anat

    2014-01-01

    Purpose. To correlate situational exposures and psychiatric disease with self-reported ocular surface symptoms in a younger veteran population involved in Operation Iraqi Freedom and Operation Enduring Freedom (OIF/OEF). Methods. Cross-sectional study of all veterans evaluated in the OIF/OEF clinic between December 2012 and April 2013 who completed the dry eye questionnaire and screening evaluations for environmental exposures, posttraumatic stress disorder (PTSD), and depression. The main outcome measures were the influence of environmental exposure and psychiatric disease on ocular surface symptoms. Results. Of 115 participants, the average age was 33 years. While overseas, exposure to incinerated waste (odds ratio [OR] 2.67, 95% confidence interval [CI] 1.23–5.81, P = 0.02) and PTSD (OR 2.68, 95% CI 1.23–5.85, P = 0.02) were associated with self-reported ocular surface symptoms. On return to the United States, older age (OR per decade 2.66, 95% CI 1.65–4.31, P = 0.04) was associated with persistent symptoms and incinerated waste was associated with resolution of symptoms (OR 0.25, 95% CI 0.07–0.90, P = 0.04). When evaluating symptom severity, 26% of the responders complained of severe ocular surface symptoms, with PTSD (OR 3.10, 95% CI 1.22–7.88, P = 0.02) and depression (OR 4.28, 95% CI 1.71–10.68, P = 0.002) being significant risk factors for their presence. Conclusions. PTSD was significantly associated with ocular surface symptoms both abroad and on return to the United States, whereas air pollution in the form of incinerated waste, was correlated with reversible symptoms. PMID:24408975

  10. Impression Cytology in a Series of Clinically Diagnosed Ocular Surface Melanocytic Lesions

    PubMed Central

    Kanavi, Mozhgan Rezaei; Hosseini, Seyed Bagher; Aliakbar-Navahi, Roshanak; Aghaei, Hossein

    2017-01-01

    Purpose: To report impression cytology (IC) results of clinically diagnosed ocular surface melanocytic lesions. Methods: Ten patients with a clinical diagnosis of an ocular surface melanocytic lesion underwent IC using cellulose acetate strips and Periodic acid Schiff-Papanicolaou staining. Excisional biopsy of lesions was performed in case of observing atypical cells on IC or at the patient's request, and excised specimens were subjected to histopathological analysis. Agreement between clinical diagnoses and IC results and between IC results and histopathology were evaluated. Results: Clinical diagnoses were nevi in 6, primary acquired melanosis (PAM) with atypia/melanoma in 2, and atypical nevus versus pigmented conjunctival intraepithelial neoplasia (CIN) in 2 cases. IC results were suggestive of a benign nevus in 7, PAM with atypia/melanoma in 2 and CIN versus an atypical epithelioid type melanocytic lesion in 1 case. IC results were consistent with the clinical diagnoses in 9 cases (Cohen's kappa index of 0.83) and excluded CIN in 1. Histopathology in 6 cases disclosed benign melanonevus in 3, malignant melanoma in the context of PAM with atypia in 2, and CIN in 1 case. Histologic results were well correlated with the IC features (Cohen's kappa index of 0.74). Conclusion: By demonstrating typical cytomorphological features of ocular superficial layers IC diagnosed the true nature of melanocytic ocular surface lesions in the majority of cases. Although IC does not substitute histopathology, given the high correlation between IC results and histopathology, it can be of great assistance in diagnosis and management of ocular surface melanocytic lesions. PMID:28299002

  11. Tear Film Mucins: Front Line Defenders of the Ocular Surface; Comparison with Airway and Gastrointestinal Tract Mucins

    PubMed Central

    Hodges, Robin R.; Dartt, Darlene A.

    2014-01-01

    The ocular surface including the cornea and conjunctiva and its overlying tear film are the first tissues of the eye to interact with the external environment. The tear film is complex containing multiple layers secreted by different glands and tissues. Each layer contains specific molecules and proteins that not only maintain the health of the cells on the ocular surface by providing nourishment and removal of waste products but also protect these cells from environment. A major protective mechanism that the corneal and conjunctival cells have developed is secretion of the innermost layer of the tear film, the mucous layer. Both the cornea and conjunctiva express membrane spanning mucins, whereas the conjunctiva also produces soluble mucins. The mucins present in the tear film serve to maintain the hydration of the ocular surface and to provide lubrication and anti-adhesive properties between the cells of the ocular surface and conjunctiva during the blink. A third function is to contribute to the epithelial barrier to prevent pathogens from binding to the ocular surface. This review will focus on the different types of mucins produced by the corneal and conjunctival epithelia. Also included in this review will be a presentation of the structure of mucins, regulation of mucin production, role of mucins in ocular surface diseases, and the differences in mucin production by the ocular surface, airways and gastrointestinal tract. PMID:23954166

  12. Fibrin glue inhibits migration of ocular surface epithelial cells.

    PubMed

    Yeung, A M; Faraj, L A; McIntosh, O D; Dhillon, V K; Dua, H S

    2016-10-01

    PurposeFibrin glue has been used successfully in numerous ophthalmic surgical procedures. Recently, fibrin glue has been used in limbal stem cell transplantation to reduce both operative time and to negate the need for sutures. The aim of this study was to determine the effects of fibrin glue on epithelial cell migration in vitro.MethodsCorneoscleral rims were split to retain the epithelial layer, Bowman's layer, and anterior stroma. Rims were cut into eight equal-sized pieces and were placed directly on culture plates or affixed with fibrin glue. Rims were maintained in culture for 25 days and epithelial cell growth was monitored. Cells were photographed to measure area or growth and immunofluorescence staining of explants for fibrin was performed.ResultsExplants that were glued demonstrated significantly delayed epithelial cell growth and migration as compared with explants without glue. By day 16, all fibrin glue had dissolved and coincided with onset of cell growth from glued explants. Cell growth commenced between days 3 and 4 for control explants without glue and around days 14-16 for explants with fibrin glue.ConclusionsFibrin glue delays epithelial cell migration by acting as a physical barrier and can potentially interfere with explant-derived limbal epithelial cell migration on to the corneal surface. We propose that glue should be used to attach the conjunctival frill of the limbal explant but care should be taken to ensure that the glue does not wrap around the explant if used to secure the explant as well. Strategic use of glue, to attach the recessed conjunctiva, can be advantageous in delaying conjunctival cell migration and reducing the need for sequential sector conjunctival epitheliectomy.

  13. Coal dust contiguity-induced changes in the concentration of TNF- and NF- B p65 on the ocular surface

    SciTech Connect

    Sun, Z.Y.; Hong, J.; Liu, Z.Y.; Jin, X.D.; Gu, C.H.

    2009-07-01

    To observe the influence of coal dust on ocular surface of coal miners and rabbits with coal dust contiguity on expression TNF- and NF- Bp65 and dry eye occurrence. Expression TNF- and NF- Bp65 in ocular surface were determined. Results showed tear production, BUT and lysozyme decreased for coal miners and rabbits with coal dust contiguity. Coal dust exposure was linked to development of xerophthalmia, and induced a higher expression of NF- B p65 and TNF- perhaps as a mechanism to resist coal dust ocular surface injury.

  14. Ocular surface disorders and tear function changes in nodulo-cystic acne.

    PubMed

    Ozdemir, Murat; Ozdemir, Gokhan; Sasmaz, Sezai; Arican, Ozer

    2005-03-01

    The aim of this study was to investigate the ocular surface disorders and tear function changes in patients with nodulo-cystic acne. Eighty-seven patients with nodulo-cystic acne vulgaris and 50 healthy subjects were included in the study. All subjects underwent full ocular examinations. Subjective ocular complaints were recorded. Corneal staining with fluorescein, tear film break-up time (BUT), and Schirmer test were applied. Abnormal tear film BUT and abnormal Schirmer scores were significantly more common in the acne group than in the control group. The tear film BUT was abnormal in 18 (20.7%) cases in the patient group and in 2 (4%) subjects in the control group (p=0.007). The mean Schirmer score was abnormal in 7 (8%) and decreased in 18 (20.7%) acne patients, and it was decreased in only 3 (6%) control subjects (p=0.005). Corneal punctuate epithelial erosions were detected in 3 (3.4%) acne patients, but not any of the control subjects. However, the difference between the groups was not statistically significant (p=0.184). Subjective ocular complaints were present in 28 cases (32.2%) in the patient group. Five (10%) subjects in the control group had such complaints (p=0.003). Tear function tests are also significantly altered in patients with nodulo-cystic acne. Our data suggest that severe acne patients should be referred to an ophthalmologist.

  15. The chemokine receptor CCR7 expressed by dendritic cells: a key player in corneal and ocular surface inflammation.

    PubMed

    Saban, Daniel R

    2014-04-01

    Dendritic cells (DCs) are highly potent stimulators of the immune system, and their contribution as such to the pathogenesis of corneal and ocular surface inflammatory disease has been well established. These vigorous antigen-presenting cells are reliant upon their effective migration from peripheral tissues (e.g., those of the ocular surface) to the lymphoid organs, where immune responses are triggered and can then cause disease. The chemokine receptor CCR7 expressed on DCs has emerged as the master mediator of this highly complex migratory process, and thus it is important in causing corneal and ocular surface inflammation. Furthermore, CCR7 has received considerable attention as a potential therapeutic target, as topically instilled antagonists of this receptor are quite effective therapeutically in a mouse model of ocular allergy. These findings and more are reviewed in the current article. In addition, the understanding regarding CCR7 function in mice and humans, and the biology of DCs that populate the ocular surface are also detailed herein. The involvement of DCs and their expression of CCR7 in corneal and ocular surface diseases such as in ocular allergy, dry eye disease, immune rejection and more, are also reviewed here.

  16. Requirement of Smad4 from Ocular Surface Ectoderm for Retinal Development

    PubMed Central

    Li, Jing; Wang, Shusheng; Anderson, Chastain; Zhao, Fangkun; Qin, Yu; Wu, Di; Wu, Xinwei; Liu, Jia; He, Xuefei; Zhao, Jiangyue; Zhang, Jinsong

    2016-01-01

    Microphthalmia is characterized by abnormally small eyes and usually retinal dysplasia, accounting for up to 11% of the blindness in children. Right now there is no effective treatment for the disease, and the underlying mechanisms, especially how retinal dysplasia develops from microphthalmia and whether it depends on the signals from lens ectoderm are still unclear. Mutations in genes of the TGF-β superfamily have been noted in patients with microphthalmia. Using conditional knockout mice, here we address the question that whether ocular surface ectoderm-derived Smad4 modulates retinal development. We found that loss of Smad4 specifically on surface lens ectoderm leads to microphthalmia and dysplasia of retina. Retinal dysplasia in the knockout mice is caused by the delayed or failed differentiation and apoptosis of retinal cells. Microarray analyses revealed that members of Hedgehog and Wnt signaling pathways are affected in the knockout retinas, suggesting that ocular surface ectoderm-derived Smad4 can regulate Hedgehog and Wnt signaling in the retina. Our studies suggest that defective of ocular surface ectoderm may affect retinal development. PMID:27494603

  17. Free amino acids: an innovative treatment for ocular surface disease.

    PubMed

    Rusciano, Dario; Roszkowska, Anna Maria; Gagliano, Caterina; Pezzino, Salvatore

    2016-09-15

    Amino acids are the basic constituents of living organisms, and have both a structural and an active dynamic role in tissue and cell physiology. Human tears contain 23 amino acids, the relative proportion of which may change with the different physiological states of the eye surface. In this review, we present a collection of data from the published literature that indicate an active role of amino acids in the maintenance of eye surface homeostasis. Moreover, another series of published clinical data indicate that supplementation of amino acids, either as food supplements or as a topical treatment in enriched eye drops, is beneficial to the eye surface, and may improve its healing in cases of eye surface disease due to different causes.

  18. A MODEL FOR THE TEAR FILM AND OCULAR SURFACE TEMPERATURE FOR PARTIAL BLINKS

    PubMed Central

    Deng, Quan; Braun, R. J.; Driscoll, T. A.; King-Smith, P. E.

    2015-01-01

    In this paper, we investigate the dynamics of tear film and the associated temperature variation for partial blinks. We investigate the mechanism of fluid supply during partial blink cycles, and compare the film thickness with observation in vivo. We find that varying the thickness of the fluid layer beneath the moving upper lid improves the agreement for the in vivo measurement of tear film thickness after a half blink. By examining the flux of the fluid, we provide an explanation of this assumption. We also investigate the temperature dynamics both at the ocular surface and inside the simulated anterior chamber. Our simulation results suggest that the ocular surface temperature readjusts rapidly to normal temperature distribution after partial blinks. PMID:25635242

  19. Corneal Expression of SLURP-1 by Age, Sex, Genetic Strain, and Ocular Surface Health

    PubMed Central

    Swamynathan, Sudha; Delp, Emili E.; Harvey, Stephen A. K.; Loughner, Chelsea L.; Raju, Leela; Swamynathan, Shivalingappa K.

    2015-01-01

    Purpose Although secreted Ly6/urokinase-type plasminogen activator receptor–related protein-1 (Slurp1) transcript is highly abundant in the mouse cornea, corresponding protein expression remains uncharacterized. Also, SLURP1 was undetected in previous tear proteomics studies, resulting in ambiguity about its baseline levels. Here, we examine mouse corneal Slurp1 expression in different sexes, age groups, strains, and health conditions, and quantify SLURP1 in human tears from healthy or inflamed ocular surfaces. Methods Expression of Slurp1 in embryonic day-13 (E13), E16, postnatal day-1 (PN1), PN10, PN20, and PN70 Balb/C, FVBN, C57Bl/6, and DBA/2J mouse corneas, Klf4Δ/ΔCE corneas with corneal epithelial–specific ablation of Klf4, migrating cells in wild-type corneal epithelial wound edge, and in corneas exposed to pathogen-associated molecular patterns (PAMPs) poly(I:C), zymosan-A, or Pam3Csk4 was examined by QPCR, immunoblots, and immunofluorescent staining. Human SLURP1 levels were quantified by ELISA in tears from 34 men and women aged 18 to 80 years. Results Expression of Slurp1, comparable in different strains and sexes, was low in E13, E16, PN1, and PN10 mouse corneas, and increased rapidly after eyelid opening in a Klf4-dependent manner. We found Slurp1 was downregulated in corneas exposed to PAMPs, and in migrating cells at the wound edge. Human SLURP1 expression, comparable in different sexes and age groups, was significantly decreased in tears from inflamed ocular surfaces (0.34%) than those from healthy individuals (0.77%). Conclusions These data describe the influence of age, sex, genetic background, and ocular surface health on mouse corneal expression of Slurp1, establish the baseline for human tear SLURP1 expression, and identify SLURP1 as a useful diagnostic and/or therapeutic target for inflammatory ocular surface disorders. PMID:26670825

  20. [A new approach for better comprehension of diseases of the ocular surface].

    PubMed

    Baudouin, C

    2007-03-01

    The mechanistic view of dry eye disease aims at completing the classic etiological approach that classifies the disease as parallel ocular surface disorders leading to lacrimal film impairment and dry eye. This approach proposes two levels of ocular surface impairment (with standard etiologies, previously validated in the NEI/Industry workshop), which may not be independent diseases but rather risk factors and/or ways to enter a self-stimulated biological process involving the ocular surface. All external disorders proposed in this model, although unlikely to be fully exhaustive, are classical mechanisms considered to be causes of tear film impairment and ocular surface damage, by tear instability and evaporation, tear hyposecretion, or both. These mechanisms, sometimes alone--when severe or becoming chronic or repeatedly present on the ocular surface and when two or more are present--may cause the patient to enter the self-stimulated loop. Tear film instability/imbalance can be considered as the key point of dry eye disease. It will cause local or diffuse hyperosmolarity of the tear film and therefore of superficial epithelial cells of the cornea and/or conjunctiva, stimulating epithelial cells and resident inflammatory cells. Cell damage in the cornea and conjunctiva, by means of apoptosis and direct mechanical and/or osmotic stress, will stimulate the reflex neurosensory arc, in turn stimulating lacrimal gland and neurogenic inflammation, with inflammatory cytokine release, MMP activation, and inflammatory involvement of the conjunctival epithelium. Goblet cell loss is thus directly related to chronic inflammation and surface cell apoptosis subsequent to cell hyperosmolarity and chronic damage, resulting in further tear film instability/imbalance. On the other hand, bacterial changes and an imbalance resulting from specific diseases or from tear film abnormalities may trigger release of endotoxins, lipopolysaccharides, and/or lipase activation, causing eyelid

  1. The Effects of Topical Antiglaucoma Drugs as Monotherapy on the Ocular Surface: A Prospective Study

    PubMed Central

    Aydin Kurna, Sevda; Acikgoz, Semih; Ozbay, Nurver; Sengor, Tomris; Olcaysu, Osman Okan

    2014-01-01

    Purpose. The aim was to compare the effects of antiglaucoma eye drops on the tear functions and ocular surface. Method. Eighty-five eyes of 43 patients with glaucoma were included into this randomized prospective study. Timolol without preservative (1), timolol with benzododecinium bromide (2), latanoprost (3), bimatoprost (4), travoprost with benzalkonium chloride (5), and brimonidine with purite (6) were given to 6 groups. Schirmer I, tear film breakup time (TBUT), staining scores, and impression cytology samples were evaluated before and during 12-month-follow-up period. Results. At the end of 12 months, there was no detected change in Schirmer I and TBUT tests indicating dry eye. Corneal staining scores were higher in groups 1 and 2, while conjunctival staining scores were higher in group 6. Goblet cell count decreased in groups 1 and 5 in superior and inferior, group 2 in superior, and groups 3 and 6 in inferior conjunctiva. Squamous metaplasia grades showed a significant increase in groups 1 and 2 at 3rd, 6th, and 12th month controls (P < 0.05). Conclusion. We observed nonserious impact on tear functions and ocular surface with antiglaucoma monotherapy. Beta blockers induced more damage on the ocular surface suggesting the role of the dosing and active substances beside preservatives. PMID:25009742

  2. In Vivo Confocal Microscopy of the Ocular Surface: From Bench to Bedside

    PubMed Central

    Villani, Edoardo; Baudouin, Christophe; Efron, Nathan; Hamrah, Pedram; Kojima, Takashi; Patel, Sanjay V.; Pflugfelder, Stephen C.; Zhivov, Andrey; Dogru, Murat

    2014-01-01

    In vivo confocal microscopy (IVCM) is an emerging technology that provides minimally invasive, high resolution, steady-state assessment of the ocular surface at the cellular level. Several challenges still remain but, at present, IVCM may be considered a promising technique for clinical diagnosis and management. This mini-review summarizes some key findings in IVCM of the ocular surface, focusing on recent and promising attempts to move “from bench to bedside”. IVCM allows prompt diagnosis, disease course follow-up, and management of potentially blinding atypical forms of infectious processes, such as acanthamoeba and fungal keratitis. This technology has improved our knowledge of corneal alterations and some of the processes that affect the visual outcome after lamellar keratoplasty and excimer keratorefractive surgery. In dry eye disease, IVCM has provided new information on the whole-ocular surface morphofunctional unit. It has also improved understanding of pathophysiologic mechanisms and helped in the assessment of prognosis and treatment. IVCM is particularly useful in the study of corneal nerves, enabling description of the morphology, density, and disease- or surgically induced alterations of nerves, particularly the subbasal nerve plexus. In glaucoma, IVCM constitutes an important aid to evaluate filtering blebs, to better understand the conjunctival wound healing process, and to assess corneal changes induced by topical antiglaucoma medications and their preservatives. IVCM has significantly enhanced our understanding of the ocular response to contact lens wear. It has provided new perspectives at a cellular level on a wide range of contact lens complications, revealing findings that were not previously possible to image in the living human eye. The final section of this mini-review provides a focus on advances in confocal microscopy imaging. These include 2D wide-field mapping, 3D reconstruction of the cornea and automated image analysis. PMID

  3. HMGB1 in the pathogenesis of ultraviolet-induced ocular surface inflammation

    PubMed Central

    Han, S J; Min, H J; Yoon, S C; Ko, E A; Park, S J; Yoon, J-H; Shin, J-S; Seo, K Y

    2015-01-01

    High-mobility group box 1 (HMGB1) functions as a transcription-enhancing nuclear protein as well as a crucial cytokine that regulates inflammation. This study demonstrated that secretion of HMGB1 due to ultraviolet (UV) radiation inducing ocular surface inflammation-mediated reactive oxygen species (ROS) production. After treating conjunctival epithelial cells with UV radiation, HMGB1 was translocated from the nucleus to the cytoplasm and then eventually to the extracellular space. HMGB1 played a crucial role in UV-induced conjunctival neutrophil infiltration, which subsided when mice were pretreated with the HMGB1 inhibitors soluble receptor for advanced glycation endproducts (sRAGEs) and HMGB1 A box protein. In case of using ROS quencher, there was decrease in UV-induced HMGB1 secretion in conjunctival epithelial cells and mice. Considering that UV-induced chronic inflammation causes ocular surface change as pterygium, we have confirmed high HMGB1 translocation and ROS expression in human pterygium. Our findings therefore revealed a previously unknown mechanism of UV-induced ocular inflammation related to ROS and HMGB1 suggesting a new medical therapeutic target. PMID:26313914

  4. Correlation between Tear Osmolarity and Other Ocular Surface Parameters in Primary Sjögren's Syndrome

    PubMed Central

    Kim, Mirinae; Kim, Hyun Seung

    2017-01-01

    Purpose To investigate the relationships between tear osmolarity and other ocular surface parameters and to determine the diagnostic value of tear osmolarity in primary Sjögren's syndrome (SS) using tear film break-up time, Schirmer I test, and cornea/conjunctiva staining. Methods We included 310 eyes of 155 patients diagnosed with dry eye disease (39 primary SS and 116 non-Sjögren dry eye disease) at Seoul St. Mary's Hospital from August 2010 to January 2015. All subjects completed the Ocular Surface Disease Index (OSDI) questionnaire and underwent ocular examinations including tear osmolarity (TearLab Osmolarity System), Schirmer I test, slit lamp examination for tear film break-up time, and corneal and conjunctival fluorescein staining. We used the mean value of both eyes for all parameters. Fluorescein staining was assessed using the Sjögren's International Collaborative Clinical Alliance ocular staining score (OSS). Results In primary SS patients (n = 39), the mean subject age was 52.5 ± 11.9 years, and 94.9% of the subjects were women. Mean tear osmolarity in SS was 311.1 ± 16.4 mOsm/L, with 16 (41.0%) subjects having values ≥316 mOsm/L. In SS, there was a positive correlation between mean tear osmolarity and OSDI score (ρ = 0.405, p = 0.011) and OSS (ρ = 0.592, p < 0.001). There was a negative correlation between mean tear osmolarity and the Schirmer I test (ρ = −0.625, p < 0.001). There was no significant correlation between mean tear osmolarity and tear film break-up time in SS (ρ = 0.110, p = 0.505). Conclusions Tear osmolarity measurements using the TearLab Osmolarity System can reflect both symptom severity (OSDI) and objective signs (Schirmer test and OSS) in SS. PMID:28243020

  5. The evolution of ocular onchocerciasis in the Volta River Basin Area over a period of five years of vector control.

    PubMed

    Dadzie, K Y; Rolland, A; Thylefors, B

    1984-03-01

    The results of an ophthalmological evaluation conducted in seven West African savannah villages before and after 5 years of vector control, were analysed to determine the effect of an interrupted or greatly reduced transmission of Onchocerca volvulus on the evolution of ocular onchocerciasis. Cross-sectional data showed a significant reduction of the prevalence of ocular onchocerciasis in five of the villages, and the rates of irreversible ocular lesions and blindness were generally lower after 5 years of vector control. A longitudinal study of a defined population showed that the ocular status of most patients with ocular onchocerciasis remained stable or improved over the 5 year period, particularly in lightly infected cases. The evolution of ocular onchocerciasis showed a deterioration in a minor proportion, restricted to cases of already existing severe lesions, resulting in blindness. A comparison of ophthalmic data from adjacent areas without vector control, indicates that a five year period of vector control may reduce the risk of developing eye lesions or blindness due to onchocerciasis by 50%.

  6. Expression of MUC5AC in ocular surface epithelial cells using cationized gelatin nanoparticles.

    PubMed

    Konat Zorzi, Giovanni; Contreras-Ruiz, Laura; Párraga, Jenny Evelin; López-García, Antonio; Romero Bello, Rafael; Diebold, Yolanda; Seijo, Begoña; Sánchez, Alejandro

    2011-10-03

    Decreased production of the mucin MUC5AC in the eye is related to several pathological conditions, including dry eye syndrome. A specific strategy for increasing the ocular levels of MUC5AC is not yet available. Using a plasmid specially designed to encode human MUC5AC, we evaluated the ability of hybrid cationized gelatin nanoparticles (NPs) containing polyanions (chondroitin sulfate or dextran sulfate) to transfect ocular epithelial cells. NPs were developed using the ionic gelation technique and characterized by a small size (<200 nm), positive zeta potential (+20/+30 mV), and high plasmid association efficiency (>95%). MUC5AC mRNA and protein were detected in conjunctival cells after in vitro transfection of the NPs. The in vivo administration of the NPs resulted in significantly higher MUC5AC expression in the conjunctiva compared to untreated control and naked plasmid. These results provide a proof-of-concept that these NPs are effective vehicles for gene therapy and candidates for restoring the MUC5AC concentration in the ocular surface.

  7. Sutureless Fixation of Amniotic Membrane for Therapy of Ocular Surface Disorders

    PubMed Central

    Kotomin, Ilya; Valtink, Monika; Hofmann, Kai; Frenzel, Annika; Morawietz, Henning; Werner, Carsten; Funk, Richard H. W.; Engelmann, Katrin

    2015-01-01

    Amniotic membrane is applied to the diseased ocular surface to stimulate wound healing and tissue repair, because it releases supportive growth factors and cytokines. These effects fade within about a week after application, necessitating repeated application. Generally, amniotic membrane is fixed with sutures to the ocular surface, but surgical intervention at the inflamed or diseased site can be detrimental. Therefore, we have developed a system for the mounting of amniotic membrane between two rings for application to a diseased ocular surface without surgical intervention (sutureless amniotic membrane transplantation). With this system, AmnioClip, amniotic membrane can be applied like a large contact lens. First prototypes were tested in an experiment on oneself for wearing comfort. The final system was tested on 7 patients in a pilot study. A possible influence of the ring system on the biological effects of amniotic membrane was analyzed by histochemistry and by analyzing the expression of vascular endothelial growth factor-A (VEGF-A), hepatocyte growth factor (HGF), fibroblast growth factor 2 (FGF 2) and pigment epithelium-derived factor (PEDF) from amniotic membranes before and after therapeutic application. The final product, AmnioClip, showed good tolerance and did not impair the biological effects of amniotic membrane. VEGF-A and PEDF mRNA was expressed in amniotic membrane after storage and mounting before transplantation, but was undetectable after a 7-day application period. Consequently, transplantation of amniotic membranes with AmnioClip provides a sutureless and hence improved therapeutic strategy for corneal surface disorders. Trial Registration ClinicalTrials.gov NCT02168790 PMID:25955359

  8. Comparison of the Efficacy of Fluorometholone With and Without Benzalkonium Chloride in Ocular Surface Disease

    PubMed Central

    Kim, Yeoun-Hee; Jung, Jae-Chang; Jung, Soon-Young; Yu, Sung; Lee, Kyoo Won

    2015-01-01

    Purpose: The purpose of this study was to compare the cytotoxicity and antiinflammatory effect of preserved and unpreserved 0.1% fluorometholone (FML). Methods: Drug-induced morphological changes and cytotoxicity were examined in human corneal epithelial cells. Dry eye was induced in mice by treatment with 0.2% benzalkonium chloride (BAC) for the first 2 weeks, and then, the eyes (4 groups; Normal saline, BAC, preserved FML, and unpreserved FML) were treated thrice daily with each formulation for the next 2 weeks. Corneal tissues were embedded in paraffin and stained with hematoxylin and eosin for histopathological examination. Immunofluorescence staining was performed for tumor necrosis factor-α, interleukin-6, and human leukocyte antigen–DR. Terminal deoxynucleotidyl transferase dUTP nick end labeling assay was performed to evaluate drug-induced cytotoxicity. Results: BAC and preserved FML caused cell shrinkage and detachment from the plate in a dose-dependent manner, and cell viability decreased significantly. However, cytotoxicity was reduced on treatment with unpreserved FML. Hematoxylin-eosin staining revealed surface desquamation, irregular surface, loss of cell borders, and stromal shrinkage in the group treated with BAC. On BAC exposure, tumor necrosis factor-α, interleukin-6, and human leukocyte antigen–DR were strongly detected, and cytotoxicity was markedly increased, as evidenced by a positive result in the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Ocular surface damage and inflammation were slightly reduced on treatment with preserved FML. In comparison, unpreserved FML did not induce morphological changes; moreover, decreased cell cytotoxicity and ocular surface inflammation were observed. Conclusions: The cytotoxicity of antiinflammatory eye drops evaluated in this study was induced by the preservative BAC. Accordingly, unpreserved FML is more effective than preserved eye drops in decreasing ocular inflammation. PMID

  9. Toll-like receptor activation modulates antimicrobial peptide expression by ocular surface cells.

    PubMed

    Redfern, Rachel L; Reins, Rose Y; McDermott, Alison M

    2011-03-01

    The ability of the ocular surface to respond to pathogens is in part attributed to toll-like receptors (TLRs) that recognize conserved motifs on various microbes. This study examines TLR expression on various ocular surface cells, if TLR agonists can modulate the expression of antimicrobial peptides (AMPs), human beta defensins (hBD) and cathelicidin (hCAP-18/LL-37) which maybe functionally active against Pseudomonas aeruginosa (PA) and if TLR agonists or AMPs can modulate TLR mRNA expression. TLR1-10 mRNA expression was examined in corneal epithelial, corneal stromal cells and conjunctival epithelial cells by RT-PCR. To confirm protein expression flow cytometry or immunostaining was performed for selected TLRs on some cell cultures. Ocular surface cells were cultured with a range of TLR agonists and then hBD-1, 2, 3, or hCAP-18 mRNA and protein expression was determined by RT-PCR and immunoblotting. In some experiments, cells were cultured with a cocktail of agonists for TLR3, 5 and 6/2 and the antimicrobial activity of the culture media was tested against PA. TLR mRNA expression was also examined in primary human corneal epithelial cells (HCEC) treated with either 3 μg/ml of hBD-2, 5 μg/ml of LL-37 or TLR4, 5 and 9 agonists. Overall, the ocular surface cells expressed mRNA for most of the TLRs but some differences were found. TLR2 was not detected in corneal fibroblasts, TLR4 was not detected in primary cultured or freshly isolated HCEC, TLR5 was not detected in conjunctival epithelial cells (IOBA-NHC) and corneal fibroblasts, TLR7 was not detected in freshly isolated HCEC and TLR10 was not detected in HCEC and IOBA-NHC. TLR8 mRNA was not expressed by any of the samples tested. Immunostaining of cadaver corneas revealed TLR5 and 9 expression throughout the cornea while TLR3 was significantly expressed only in the epithelium. Flow cytometry and immunostaining revealed cultured fibroblasts expressed TLR9 but had no significant TLR3 expression. hBD-2 expression

  10. Molecular and chemical investigations and comparisons of biomaterials for ocular surface regeneration.

    PubMed

    Kim, Yeon-Hee; Jin, Kyung-Hyun; Kim, Jae Hyung; Park, Dong Jin; Choi, Samjin; Park, Hun-Kuk

    2014-03-01

    This study investigated and compared the ultrastructural and chemical properties of representative biomaterials for ocular surface regeneration: a human amniotic membrane (AM) in a basal plate, a human AM in reflected chorion, a preserved AM, and a human corneo-scleral tissue. Assessments of the morphological differences in the extracellular matrices were evaluated by hematoxylin-eosin, Masson's trichrome (for total collagen), and picrosirius-red (for newly synthesized collagen) staining. Assessments of the changes in the molecular structures and chemical compositions of the biomaterials for ocular surface regeneration were evaluated by Raman spectroscopy. A placental AM (52 %) was a dense and thick collagenous structure compared to a reflected AM (23 %). The spectroscopy did not obtain any structural information for a preserved AM. The cornea group (100 %, control) and sclera group (104 %) showed the collagen lamellae and interfibrillar spacing, and a slight inflammatory reaction with more fibrous and granulomatous tissues. There was a formation of newly synthesized collagen in a placental AM, while there were few collagen components in a reflected AM. Human AM tissues showed consistent Raman spectra and the characteristic collagen bands, similar to the corneal and scleral tissues. Therefore, these findings suggest that human placental AM and reflected AM are structurally suitable for scleral and corneal surface regeneration, respectively, while human placental or preserved AM and reflected AM are molecularly and chemically suitable for corneal and scleral surface regeneration, respectively.

  11. A decade of silicone hydrogel development: surface properties, mechanical properties, and ocular compatibility.

    PubMed

    Tighe, Brian J

    2013-01-01

    Since the initial launch of silicone hydrogel lenses, there has been a considerable broadening in the range of available commercial material properties. The very mobile silicon-oxygen bonds convey distinctive surface and mechanical properties on silicone hydrogels, in which advantages of enhanced oxygen permeability, reduced protein deposition, and modest frictional interaction are balanced by increased lipid and elastic response. There are now some 15 silicone hydrogel material variants available to practitioners; arguably, the changes that have taken place have been strongly influenced by feedback based on clinical experience. Water content is one of the most influential properties, and the decade has seen a progressive rise from lotrafilcon-A (24%) to efrofilcon-A (74%). Moduli have decreased over the same period from 1.4 to 0.3 MPa, but not solely as a result of changes in water content. Surface properties do not correlate directly with water content, and ingenious approaches have been used to achieve desirable improvements (e.g., greater lubricity and lower contact angle hysteresis). This is demonstrated by comparing the hysteresis value of the earliest (lotrafilcon-A, >40°) and most recent (delefilcon-A, <10°) coated silicone hydrogels. Although wettability is important, it is not of itself a good predictor of ocular response because this involves a much wider range of physicochemical and biochemical factors. The interference of the lens with ocular dynamics is complex leading separately to tissue-material interactions involving anterior and posterior lens surfaces. The biochemical consequences of these interactions may hold the key to a greater understanding of ocular incompatibility and end of day discomfort.

  12. Preliminary Effects of Oral Uridine on the Ocular Surface in Dry Eye Patients

    PubMed Central

    Chang, Ki Cheol; Oh, Joo Youn; In, Youn Seok; Shin, Ki Cheul; Wee, Won Ryang; Lee, Jin Hak; Park, Myung Gyu

    2009-01-01

    We designed a randomized, double blinded, 3-months controlled prospective clinical study to investigate effects of oral uridine on the ocular surface in dry eye patients. Twenty-seven patients who diagnosed as dry eye with lower than 5 mm of wetting in the Schirmer strip, with corneal epithelial erosion and who completely followed-up till 3 months were enrolled. Corneal-conjunctival fluorescein staining, non-anesthetic Schirmer test, impression cytology, and Ocular Surface Disease Index (OSDI) were evaluated in the experimental and placebo groups at the baseline, 1 and 3 months after start of medication in a double blinded manner. Fluorescein stain score of the cornea was markedly decreased in oral uridine group compared to the placebo group at 3 months after medication (P=0.032, Mann-Whitney U test). The Schirmer wetting score for the oral uridine group was significantly increased (P=0.001, Wilcoxon signed rank test) at 3 months and its difference between two groups was statistically significant (P=0.030, Mann-Whitney U test). OSDI scores were significantly decreased at 1 and 3 months in treatment group. Oral uridine is effective in treatment of dry eyes. PMID:19654956

  13. Effect of benzalkonium chloride-free latanoprost ophthalmic solution on ocular surface in patients with glaucoma

    PubMed Central

    Walimbe, Tejaswini; Chelerkar, Vidya; Bhagat, Purvi; Joshi, Abhijeet; Raut, Atul

    2016-01-01

    Introduction Benzalkonium chloride (BAK), included as a preservative in many topical treatments for glaucoma, induces significant toxicity and alters tear breakup time (TBUT). BAK-containing latanoprost, an ester prodrug of prostaglandin F2α, can cause ocular adverse events (AEs) associated with BAK. The purpose of this study was to evaluate the efficacy and safety of BAK-free latanoprost. Patients and methods A prospective, open-label, single-arm, multicenter, 8-week study in patients with primary open-angle glaucoma or ocular hypertension taking BAK-containing latanoprost for ≥12 months was performed. Patients were switched to BAK-free latanoprost ophthalmic solution 0.005% administered once daily, and eyes were assessed after 28 and 56 days. Primary efficacy and safety variables were TBUT and treatment-emergent AEs, respectively. Results At day 56, 40 eyes were evaluable. Mean TBUT increased significantly from baseline (3.67±1.60 seconds) to 5.03±2.64 and 6.06±3.39 seconds after 28 and 56 days of treatment with BAK-free latanoprost (P<0.0001). Ocular Surface Disease Index© (OSDI©) score also decreased significantly to 12.06±13.40 and 7.06±10.75 at 28 and 56 days, respectively, versus baseline (18.09±18.61, P<0.0001). In addition, inferior corneal staining score decreased significantly to 0.53 from baseline (0.85, P=0.0033). A reduction in conjunctival hyperemia and intraocular pressure was observed at both time points. No treatment-related serious AEs were evident and 12 (26.08%) treatment-emergent AEs occurred in seven patients, with eye pain and irritation being the most frequent. No clinically significant changes in vital signs or slit lamp examinations were observed. Conclusion Results indicate that switching from BAK-containing latanoprost to BAK-free latanoprost resulted in significant improvements in TBUT, OSDI© score, and inferior corneal staining score, and measurable reductions in conjunctival hyperemia score. Furthermore, BAK

  14. Model-based conifer crown surface reconstruction from multi-ocular high-resolution aerial imagery

    NASA Astrophysics Data System (ADS)

    Sheng, Yongwei

    2000-12-01

    Tree crown parameters such as width, height, shape and crown closure are desirable in forestry and ecological studies, but they are time-consuming and labor intensive to measure in the field. The stereoscopic capability of high-resolution aerial imagery provides a way to crown surface reconstruction. Existing photogrammetric algorithms designed to map terrain surfaces, however, cannot adequately extract crown surfaces, especially for steep conifer crowns. Considering crown surface reconstruction in a broader context of tree characterization from aerial images, we develop a rigorous perspective tree image formation model to bridge image-based tree extraction and crown surface reconstruction, and an integrated model-based approach to conifer crown surface reconstruction. Based on the fact that most conifer crowns are in a solid geometric form, conifer crowns are modeled as a generalized hemi-ellipsoid. Both the automatic and semi-automatic approaches are investigated to optimal tree model development from multi-ocular images. The semi-automatic 3D tree interpreter developed in this thesis is able to efficiently extract reliable tree parameters and tree models in complicated tree stands. This thesis starts with a sophisticated stereo matching algorithm, and incorporates tree models to guide stereo matching. The following critical problems are addressed in the model-based surface reconstruction process: (1) the problem of surface model composition from tree models, (2) the occlusion problem in disparity prediction from tree models, (3) the problem of integrating the predicted disparities into image matching, (4) the tree model edge effect reduction on the disparity map, (5) the occlusion problem in orthophoto production, and (6) the foreshortening problem in image matching, which is very serious for conifer crown surfaces. Solutions to the above problems are necessary for successful crown surface reconstruction. The model-based approach was applied to recover the

  15. [Use of stem cells cultured ex vivo for ocular surface reconstruction].

    PubMed

    Ricardo, José Reinaldo da Silva; Gomes, José Alvaro Pereira

    2010-01-01

    Lesions on the ocular surface can destroy the stem cells from the limbus and cause limbal stem cell deficiency. The limbal stem cell deficiency is marked by conjunctivalization, which can be defined as the invasion of conjunctival epithelium over the cornea. This process is accompanied by varying degrees of corneal changes such as neovascularization, inflammation, recurrent erosions, persistent epithelial defects, destruction of basement membrane of epithelium and stromal healing. Often, these changes are associated with poor visual acuity, photophobia and ocular discomfort. The best treatment for this disease is not known and varies in unilateral or bilateral cases. Among the treatments available, transplantation of limbal autograft or allograft is one of the most used. To improve the outcome of allotransplantation, some researchers use the transplantation of corneal epithelium cultured in the laboratory by ex vivo expansion of limbal stem cells, but due to limited availability of autologous tissue from the limbus and the risk of complications associated with immunosuppression in allogeneic tissue transplantation, researches of others options of stem cell cultured ex vivo have been described in experimental and clinical stage. This review describes the new types of stem cells cultured ex vivo, their current results and future potential.

  16. Co-existing squamous cell carcinoma and hemangioma on the ocular surface of a cat.

    PubMed

    Perlmann, Eduardo; da Silva, Enry Garcia; Guedes, Pedro Mancini; Barros, Paulo Sergio de Moraes

    2010-01-01

    A 14-year-old spayed female domestic short-haired cat was presented for evaluation of a mass in the right eye. Ophthalmic examination revealed a blind right eye and presence of two distinct masses: a pink and a red-to-brown mass, the latter occupying most of the cornea and part of the conjunctiva. Exenteration was performed under general anesthesia, and the ocular tissues were processed routinely for histopathology. Upon microscopic examination, a malignant epithelial neoplasm and a benign vascular neoplasm were present in the cornea. The conjunctiva and the third eyelid were also affected. Upon immunohistochemistry, the epithelial tumor was positive for cytokeratin and negative for vimentin and the endothelial tumor was negative for cytokeratin and positive for vimentin. A diagnosis of squamous cell carcinoma (SCC) and hemangioma was made. The SCC was affecting the cornea, bulbar conjunctiva (lateral and inferior) and the base of the third eyelid, whereas the hemangioma was affecting the cornea and medial limbus. To the authors' knowledge, this is the first report of concomitant SCC and hemangioma affecting the ocular surface in a cat.

  17. Ocular toxocariasis.

    PubMed

    Arevalo, J Fernando; Espinoza, Juan V; Arevalo, Fernando A

    2013-01-01

    Ocular toxocariasis is an uncommon worldwide parasitic infection that affects mostly children and is found in both rural and metropolitan areas. In many parts of the world, parasitic infections of the eye are a major cause of blindness. The diagnosis of toxocariasis is essentially clinical, based on the lesion morphology and supportive laboratory data such as serum enzyme-linked immunosorbent assay (ELISA) titers and ELISA Toxocara titers on aqueous humor; other diagnostic methods are imaging studies including optical coherence tomography, fluorescein angiography, computed tomography, and ocular ultrasound. Treatment is directed at complications arising from intraocular inflammation and vitreous membrane traction. Early vitrectomy may be of value both diagnostically and therapeutically.

  18. Quercetin and the ocular surface: What we know and where we are going.

    PubMed

    McKay, Tina B; Karamichos, Dimitrios

    2017-03-01

    Flavonoids are a class of plant and fungus secondary metabolites that serve functional roles in protecting against UV-induced oxidative stress, mediating auxin signaling, and promoting microbial defense. Flavonoids are extremely abundant in nature where their potent antioxidant capacity and very low toxicity makes them highly attractive as potential therapeutic agents. In terms of clinical applications, neither the Food and Drug Administration (FDA) nor the European Food Safety Authority (EFSA) has approved any health claims or drugs related to the use of flavonoids for therapeutic purposes. Quercetin is a common flavonol that has been shown to have potent antioxidant, anti-inflammatory, and anti-fibrotic activities both in vitro and in vivo in various tissues. Recently, the application of quercetin as a therapeutic has been gaining attention in the ocular surface scientific community in the study of dry eye, keratoconus, inflammation, and neovascularization of the cornea. This review will discuss the latest findings and the use of quercetin for the treatment of dystrophies of the ocular surface. Impact statement The eye represents a small portion of the human body, accounting for one decimal fraction of the anterior body surface. The cornea is an avascular, transparent tissue that acts as a primary barrier against mechanical and infectious damaging agents, protecting the internal structures of the eye. Corneal survival and function are affected by a number of factors including but not limited to injury, trauma, infection, genetics, and environment. Corneal injury, or trauma, often leads to loss of corneal transparency and even blindness. The concept of "curing" corneal opacity has been discussed in published form for over 200 years. Currently, full corneal transplant is the only treatment option. There is a strong interest in developing natural therapeutic products that come with minimum side effects. A novel antioxidant flavonoid, quercetin, has been gaining

  19. Bilateral recurrent ocular surface squamous cell cancer associated with epidermodysplasia verruciformis

    PubMed Central

    Arora, Tarun; Sharma, Sourabh; Sharma, Namrata; Titiyal, Jeewan S

    2015-01-01

    A 17-year-old boy, presented with a 2-year history of bilateral, recurrent ocular surface mass. Dermatological evaluation revealed the presence of multiple hypopigmented macules over his body. Skin biopsy showed features typical of epidermodysplasia verruciformis. Topical mitomycin C (0.02%) was administered in both eyes for 6 weeks (three 1-week cycles over 6 weeks). While the mass in the left eye regressed, the mass in the right eye was excised under guidance of intraoperative frozen section. Triple-freeze thaw cryotherapy of the surrounding conjunctiva along with placement of amniotic membrane graft was performed. Postoperative mitomycin C (0.02%) was administered for another 6 weeks (three 1-week cycles over 6 weeks) in both eyes. At 4 years of follow-up, no recurrence has been noted. PMID:25636630

  20. Bilateral recurrent ocular surface squamous cell cancer associated with epidermodysplasia verruciformis.

    PubMed

    Arora, Tarun; Sharma, Sourabh; Sharma, Namrata; Titiyal, Jeewan S

    2015-01-30

    A 17-year-old boy, presented with a 2-year history of bilateral, recurrent ocular surface mass. Dermatological evaluation revealed the presence of multiple hypopigmented macules over his body. Skin biopsy showed features typical of epidermodysplasia verruciformis. Topical mitomycin C (0.02%) was administered in both eyes for 6 weeks (three 1-week cycles over 6 weeks). While the mass in the left eye regressed, the mass in the right eye was excised under guidance of intraoperative frozen section. Triple-freeze thaw cryotherapy of the surrounding conjunctiva along with placement of amniotic membrane graft was performed. Postoperative mitomycin C (0.02%) was administered for another 6 weeks (three 1-week cycles over 6 weeks) in both eyes. At 4 years of follow-up, no recurrence has been noted.

  1. A systematic review on the impact of diabetes mellitus on the ocular surface.

    PubMed

    Shih, K Co; Lam, K S-L; Tong, L

    2017-03-20

    Diabetes mellitus is associated with extensive morbidity and mortality in any human community. It is well understood that the burden of diabetes is attributed to chronic progressive damage in major end-organs, but it is underappreciated that the most superficial and transparent organ affected by diabetes is the cornea. Different corneal components (epithelium, nerves, immune cells and endothelium) underpin specific systemic complications of diabetes. Just as diabetic retinopathy is a marker of more generalized microvascular disease, corneal nerve changes can predict peripheral and autonomic neuropathy, providing a window of opportunity for early treatment. In addition, alterations of immune cells in corneas suggest an inflammatory component in diabetic complications. Furthermore, impaired corneal epithelial wound healing may also imply more widespread disease. The non-invasiveness and improvement in imaging technology facilitates the emergence of new screening tools. Systemic control of diabetes can improve ocular surface health, possibly aided by anti-inflammatory and vasoprotective agents.

  2. Effects of Exposure to Ozone on the Ocular Surface in an Experimental Model of Allergic Conjunctivitis

    PubMed Central

    Lee, Hun; Kim, Eung Kweon; Kim, Hee Young; Kim, Tae-im

    2017-01-01

    Based on previous findings that ozone can induce an inflammatory response in the ocular surface of an animal model and in cultured human conjunctival epithelial cells, we investigated whether exposure to ozone exacerbates symptoms of allergic conjunctivitis. We evaluated the effects of exposure to ozone on conjunctival chemosis, conjunctival injection, corneal and conjunctival fluorescein staining scores, production of inflammatory cytokines in tears, and aqueous tear production in a mouse model of allergic conjunctivitis. To validate our in vivo results, we used interleukin (IL)-1α-pretreated conjunctival epithelial cells as an in vitro substitute for the mouse model. We evaluated whether exposure to ozone increased the inflammatory response and altered oxidative status and mitochondrial function in IL-1α-pretreated conjunctival epithelial cells. In the in vivo study, ozone induced increases in conjunctival chemosis, conjunctival injection, corneal and conjunctival fluorescein staining scores, and production of inflammatory cytokines, accompanied by a decrease in tear volume. In the in vitro study, exposure to ozone led to additional increases in IL-6 and tumor necrosis factor-α mRNA levels, which were already induced by treatment with IL-1α. Ozone did not induce any changes in cell viability. Pretreatment with IL-1α increased the expression of manganese superoxide dismutase, and exposure to ozone led to additional increments in the expression of this antioxidant enzyme. Ozone did not induce any changes in mitochondrial activity or expression of mitochondrial enzymes and proteins related to mitochondrial function, with the exception of phosphor-mammalian target of rapamycin. Treatment with butylated hydroxyanisole, a free radical scavenger, attenuated the ozone-induced increases in IL-6 expression in IL-1α-pretreated conjunctival epithelial cells. Therefore, we conclude that exposure to ozone exacerbates the detrimental effects on the integrity of the ocular

  3. Prevalence and Severity of Ocular Surface Neoplasia in African Nations and Need for Early Interventions

    PubMed Central

    Reynolds, Jacob W.; Pfeiffer, Margaret L.; Ozgur, Omar; Esmaeli, Bita

    2016-01-01

    Ocular surface squamous neoplasia (OSSN) is a common ocular surface tumor with an increased incidence in African countries (3.4 and 3.0 cases/year/100,000). Despite its potential for vision loss and death, OSSN remains largely neglected by both eye and HIV care programs in Africa. The purpose of this review is to identify the barriers to timely diagnosis and early interventions for OSSN in Africa. PubMed searches were conducted targeting previous use of topical chemotherapy (interferon alpha 2b, Mitomycin-C, 5-Fluorouracil) and Human papillomavirus (HPV) vaccination in Africa. We found that OSSN is a significant vision and life-threatening health problem in Africa leading to significant loss of vision, as well as facial disfigurement and social stigma. We did not find any reports on the use of topical interferon, Mitomycin-C or HPV vaccination for OSSN in Africa. One report on the use of topical 5-FU for OSSN in Africa was found. Common barriers to early detection and management of OSSN in Africa include lack of sufficient laboratory infrastructure, lack of trained healthcare personnel, lack of compliance with follow-up visits, cost of topical chemotherapies, and cultural preferences for traditional medicines. In conclusion, OSSN is a significant vision and life-threatening health problem in Africa. There is not much literature on prevention or treatment options for early stages of OSSN in Africa. The use of topical chemotherapy as early interventions and judicious use of smart phone Apps to help with remote diagnosis of early OSSN should be further explored. PMID:27994810

  4. Age-related changes and diseases of the ocular surface and cornea.

    PubMed

    Gipson, Ilene K

    2013-12-13

    Aging of the ocular surface and corneal tissues, major components of the visual system, causes major eye disease and results in substantial cost in medical and social terms. These diseases include the highly prevalent dry eye disease that affects the ocular surface and its glands, leading to tear film alterations, discomfort, and decreased vision. Studies show that 14.4% of the population in the United States older than 50 years have dry eye disease and demonstrate that it is particularly prevalent among women. Annual medical costs per patient with dry eye in the United States are estimated at $783 per year, with an overall medical cost adjusted to prevalence of $3.84 billion per year. Societal costs, which include loss of productivity, are estimated per patient at $11,302 per year, with overall costs adjusted to prevalence of $55.4 billion per year. Because there are few effective treatments for the disease, more research on its etiology and mechanisms is warranted and needed. Increased public education about risk factors for the disease is also required. Another major age-related eye disease of the cornea that leads to vision impairment and potentially blindness if left untreated is Fuchs' endothelial corneal dystrophy. This disease leads to loss of the endothelial cells on the internal side of the cornea that are responsible for keeping the cornea in the proper hydration state to ensure its transparency to light. The mechanism of cell loss is unknown, and the only treatment available to date is surgical transplantation of the cornea or inner part of the cornea. These medically costly procedures require donor corneas, eye banking, and medical follow-up, with accrued costs. Fuchs' endothelial corneal dystrophy is a major cause of corneal transplantation in the United States; therefore, research support is needed to determine the mechanism of this age-related disease, to develop medical, nonsurgical methods for treatment.

  5. Influence of Light Emitting Diode-Derived Blue Light Overexposure on Mouse Ocular Surface

    PubMed Central

    Lee, Hyo Seok; Cui, Lian; Li, Ying; Choi, Ji Suk; Choi, Joo-Hee; Li, Zhengri; Kim, Ga Eon; Choi, Won

    2016-01-01

    Purpose To investigate the influence of overexposure to light emitting diode (LED)-derived light with various wavelengths on mouse ocular surface. Methods LEDs with various wavelengths were used to irradiate C57BL/6 mice at an energy dose of 50 J/cm2, twice a day, for 10 consecutive days. The red, green, and blue groups represented wavelengths of 630 nm, 525 nm, and 410 nm, respectively. The untouched group (UT) was not exposed to LED light and served as the untreated control. Tear volume, tear film break-up time (TBUT), and corneal fluorescein staining scores were measured on days 1, 3, 5, 7, and 10. Levels of interferon (IFN)-γ, interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α were measured in the cornea and conjunctiva using a multiplex immunobead assay at day 10. Levels of malondialdehyde (MDA) were measured with an enzyme-linked immunosorbent assay. Flow cytometry, 2’7’-dichlorofluorescein diacetate (DCF-DA) assay, histologic analysis, immunohistochemistry with 4-hydroxynonenal, and terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL) staining were also performed. Results TBUT of the blue group showed significant decreases at days 7 and 10, compared with the UT and red groups. Corneal fluorescein staining scores significantly increased in the blue group when compared with UT, red, and green groups at days 5, 7, and 10. A significant increase in the corneal levels of IL-1β and IL-6 was observed in the blue group, compared with the other groups. The blue group showed significantly increased reactive oxygen species production in the DCF-DA assay and increased inflammatory T cells in the flow cytometry. A significantly increased TUNEL positive cells was identified in the blue group. Conclusions Overexposure to blue light with short wavelengths can induce oxidative damage and apoptosis to the cornea, which may manifest as increased ocular surface inflammation and resultant dry eye. PMID:27517861

  6. Evaluation of Ocular Surface Health in Patients with Obstructive Sleep Apnea Syndrome

    PubMed Central

    Karaca, Emine Esra; Akçam, Hanife Tuba; Uzun, Feyzahan; Özdek, Şengül; Ulukavak Çiftçi, Tansu

    2016-01-01

    Objectives: To evaluate ocular surface health in obstructive sleep apnea syndrome (OSAS) and to investigate the tendency of these patients toward dry eyes. Materials and Methods: Fifty patients who underwent polysomnography and were diagnosed with OSAS and 50 normal control subjects were compared with respect to ocular surface disease index (OSDI), Schirmer I test and tear film break-up time (TBUT) values. Results: Patients were grouped as mild (n=15, 30%), moderate (n=15, 30%) and severe (n=20, 40%) according to apnea-hypopnea index values. The right eyes of patients were included in both groups. OSDI values were as follows: control group, 18.7±8.5; mild OSAS group, 40.2±2.8; moderate OSAS group, 48.5±2.2 and severe OSAS group, 62.7±2.3 (p<0.001). TBUT values were as follows: control group, 12.3±4.9; mild OSAS group, 8.2±4.7; moderate OSAS group, 5.8±2.1 and severe OSAS group, 4.2±3.7 (p<0.001). Schirmer values were as follows: control group, 18±6.1 mm; mild OSAS group, 12.9±6.7 mm; moderate OSAS group, 8.5±5.2 mm and severe OSAS group, 7.9±4.7 mm (p<0.001). Conclusion: Patients with OSAS seem to have a tendency toward dry eyes. Clinicians should be aware of dry eye development in these patients. PMID:27800271

  7. Therapeutic Effects of Sodium Hyaluronate on Ocular Surface Damage Induced by Benzalkonium Chloride Preserved Anti-glaucoma Medications

    PubMed Central

    Liu, Xing; Yu, Fen-Fen; Zhong, Yi-Min; Guo, Xin-Xing; Mao, Zhen

    2015-01-01

    Background: Long-term use of benzalkonium chloride (BAC)-preserved drugs is often associated with ocular surface toxicity. Ocular surface symptoms had a substantial impact on the glaucoma patients’ quality of life and compliance. This study aimed to investigate the effects of sodium hyaluronate (SH) on ocular surface toxicity induced by BAC-preserved anti-glaucoma medications treatment. Methods: Fifty-eight patients (101 eyes), who received topical BAC-preserved anti-glaucoma medications treatment and met the severe dry eye criteria, were included in the analysis. All patients were maintained the original topical anti-glaucoma treatment. In the SH-treated group (56 eyes), unpreserved 0.3% SH eye drops were administered with 3 times daily for 90 days. In the control group (55 eyes), phosphate-buffered saline were administered with 3 times daily for 90 days. Ocular Surface Disease Index (OSDI) questionnaire, break-up time (BUT) test, corneal fluorescein staining, corneal and conjunctival rose Bengal staining, Schirmer test, and conjunctiva impression cytology were performed sequentially on days 0 and 91. Results: Compared with the control group, SH-treated group showed decrease in OSDI scores (Kruskal-Wallis test: H = 38.668, P < 0.001), fluorescein and rose Bengal scores (Wilcoxon signed-ranks test: z = −3.843, P < 0.001, and z = −3.508, P < 0.001, respectively), increase in tear film BUT (t-test: t = −10.994, P < 0.001) and aqueous tear production (t-test: t = −10.328, P < 0.001) on day 91. The goblet cell density was increased (t-test: t = −9.981, P < 0.001), and the morphology of the conjunctival epithelium were also improved after SH treatment. Conclusions: SH significantly improved both symptoms and signs of ocular surface damage in patients with BAC-preserved anti-glaucoma medications treatment. SH could be proposed as a new attempt to reduce ocular surface toxicity, and alleviate symptoms of ocular surface damage in BAC-preserved anti

  8. Mucoadhesive Chitosan–Dextran Sulfate Nanoparticles for Sustained Drug Delivery to the Ocular Surface

    PubMed Central

    Chaiyasan, Wanachat; Srinivas, Sangly P.

    2013-01-01

    Abstract Purpose To characterize nanoparticles produced by self-assembly of oppositely charged polymers, cationic chitosan (CS), and anionic dextran sulfate (DS), for drug delivery to the ocular surface. The goal is to overcome the short residence time of topical drugs through their sustained release from mucoadhesive nanoparticles. Methods Chitosan–dextran sulfate nanoparticles (CDNs) were produced by mixing CS and DS; polyethylene glycol-400 was used as a surface stabilizing agent. Fourier transform infrared spectroscopy (FTIR) spectra of CS, DS, and CDNs were determined in the wavenumber range of 4,000–700 cm−1 to assess the ionic interactions in the formation of CDNs. The physicochemical properties, entrapment efficacy, and dissolution profile of CDNs were investigated using Rhodamine B (RhB) and Nile Red (NR) as drug analogs. The mucoadhesiveness of the CDNs was assessed by imaging the retention of the fluorescein isothiocyanate-labeled CDNs on the cornea ex vivo, which was subjected to shear stress by a steady stream of saline solution. Results CDNs were obtained by the polyelectrolyte complexation technique. The FTIR spectra of CDNs showed spectral shifts in the amine and sulfate regions, confirming an involvement of electrostatic interactions between cationic CS and anionic DS. The CDNs were spherical in shape and segregated. They possessed a particle size of ∼400 nm with a polydispersity index of 0.3 and exhibited a zeta potential of ∼40 mV. A high entrapment efficacy of up to 80% was observed with both RhB and NR. In the dissolution experiments, NR was released from CDNs within 60 min, but RhB was not released. This indicates that the release of drugs could depend on their molecular interactions with the particle. Exposure of CDNs to lysozyme, which is found in tears, had no effect on the mean particle size or the surface charge. Instillation of NR, RhB, and FITC in the presence of saline irrigation resulted in their rapid disappearance

  9. Ocular Surface and Tear Film Changes in Older Women Working with Computers.

    PubMed

    Ribelles, Alfredo; Galbis-Estrada, Carmen; Parras, Maria A; Vivar-Llopis, Bárbara; Marco-Ramírez, Carla; Diaz-Llopis, Manuel

    2015-01-01

    The aim of this work is to investigate changes in the ocular surface (OS) and tear film (TF) by means of questionnaire-based subjective symptoms, TF break-up time, Schirmer test, and TF analysis in women working with computers and to analyze the effects of the oral supplementation with antioxidants/omega 3 fatty acids (A/ω3) in the OS outcomes. Women aged 40-65 years (n = 148) were recruited at the Administrative Offices of Valencia (Spain) and distributed into two age groups, 40-52 years (AGE1; n = 87) and 53-65 years (AGE2; n = 61), and then subdivided according to being (or not) computer users (CUG; NCUG) during the workday. Homogeneous subgroups were randomly assigned (or not) to the daily intake of three pills of A/ω3 for three months. At baseline and at the end of follow-up, personalized interviews and ocular examination were done. Reflex tear samples were collected from the inferior meniscus and processed for a multiplexed particle-based flow cytometry assay to measure proinflammatory molecules. Statistics were performed using the SPSS 15.0 program. The OS pathology was clinically evident in the AGE1-CUG (33%) versus the AGE2-CUG (64%) of women. Significantly higher interleukins-1β and -6 tear levels were found in the AGE1 versus the AGE2 women employees (P = 0.006 and P = 0.001, resp.), as well as in the CUG versus the NCUG (P = 0.001 and P = 0.000, resp.). Supplementation with A/ω3 positively influenced the OS pathology as manifested by the amelioration of the clinical signs/symptoms related to computer uses. Strategies involving a safe environment and oral micronutrient supplements may be managed within eye-care standards in older women.

  10. Ocular Surface and Tear Film Changes in Older Women Working with Computers

    PubMed Central

    Ribelles, Alfredo; Galbis-Estrada, Carmen; Parras, Maria A.; Vivar-Llopis, Bárbara; Marco-Ramírez, Carla; Diaz-Llopis, Manuel

    2015-01-01

    The aim of this work is to investigate changes in the ocular surface (OS) and tear film (TF) by means of questionnaire-based subjective symptoms, TF break-up time, Schirmer test, and TF analysis in women working with computers and to analyze the effects of the oral supplementation with antioxidants/omega 3 fatty acids (A/ω3) in the OS outcomes. Women aged 40–65 years (n = 148) were recruited at the Administrative Offices of Valencia (Spain) and distributed into two age groups, 40–52 years (AGE1; n = 87) and 53–65 years (AGE2; n = 61), and then subdivided according to being (or not) computer users (CUG; NCUG) during the workday. Homogeneous subgroups were randomly assigned (or not) to the daily intake of three pills of A/ω3 for three months. At baseline and at the end of follow-up, personalized interviews and ocular examination were done. Reflex tear samples were collected from the inferior meniscus and processed for a multiplexed particle-based flow cytometry assay to measure proinflammatory molecules. Statistics were performed using the SPSS 15.0 program. The OS pathology was clinically evident in the AGE1-CUG (33%) versus the AGE2-CUG (64%) of women. Significantly higher interleukins-1β and -6 tear levels were found in the AGE1 versus the AGE2 women employees (P = 0.006 and P = 0.001, resp.), as well as in the CUG versus the NCUG (P = 0.001 and P = 0.000, resp.). Supplementation with A/ω3 positively influenced the OS pathology as manifested by the amelioration of the clinical signs/symptoms related to computer uses. Strategies involving a safe environment and oral micronutrient supplements may be managed within eye-care standards in older women. PMID:26557673

  11. Touch-free measurement of body temperature using close-up thermography of the ocular surface.

    PubMed

    Vogel, Benjamin; Wagner, Heike; Gmoser, Johanna; Wörner, Anja; Löschberger, Anna; Peters, Laura; Frey, Anna; Hofmann, Ulrich; Frantz, Stefan

    2016-01-01

    In experimental animal research body temperature (BT) is measured for the objective determination of an animals' physiological condition. Invasive, probe-based measurements are stressful and can influence experimental outcome. Alternatively BT can be determined touch-free from the emitted heat of the organism at a single spot using infrared thermometers [1]. To get visual confirmation and find more appropriate surfaces for measurement a hand-held thermal imager was equipped with a self-made, cheap, 3D-printable close-up lens system that reproducibly creates eight-time magnified thermal images and improves sensitivity. This setup was used to establish ocular surface temperature (OST), representing the temperature of the brain-heart axis, as a touch-free alternative for measurement of BT in mice, rats, rabbits and humans.OST measurement after isoflurane exposure and myocardial infarction (MI) experiments in mice revealed high physiological relevance and sensitivity, the possibility to discriminate between MI and sham operations in one hour and even long-term outcome-predictive capabilities of OST after MI. Summarized here we present: •Self-made close-up lens for thermal imaging cameras for eight-time magnification•Establishment of OST for touch-free determination of BT in rodents and humans•Short- and long-term predictive capabilities of OST in experimental MI in mice.

  12. Effects of artificial tears on rabbit ocular surface healing after exposure to benzalkonium chloride.

    PubMed

    Zhang, Yuqiu; Cao, Hong; Lin, Tong; Gong, Lan

    2016-10-01

    The aim of the study was to observe the effect of different artificial tears on healing the drug-induced keratopathy. To this aim, 64 rabbits received topical administration of 0.01% benzalkonium chloride to establish models and were divided into four groups. The control group received ocular saline solution (Saline), while the others were treated with Refresh Plus® (RF), Hycosan® (H) and Systane® Ultra (SU). Surface abnormalities were examined daily using slit-lamp. Fluorescein staining, histopathological and transmission electron microscopic (TEM) examination were performed at day 0, 2 weeks, and 1 and 2 months. A significant difference was observed between RF and SU, but not between H and SU at 2 weeks. TEM examination revealed new microvilli close to the cavity surface, and the number of microvilli in SU was greater than in H at 2 weeks and 1 month. Based on the results, the effect in the SU group was the most significant. Eye drops with nontoxic preservative such as SU are an alternative to treat drug-induced keratopathy.

  13. Transport and interaction of cosmetic product material within the ocular surface: beauty and the beastly symptoms of toxic tears.

    PubMed

    Malik, Adeela; Claoué, Charles

    2012-12-01

    Eye cosmetics such as mascara, eye shadow and eyeliner are used extensively to highlight the eyes, and are normally applied external to the ocular surface. Adverse reactions of cosmetics within the ocular surface include mild discomfort, eyelid dermatitis, pre-corneal tear film instability, and keratitis. These are attributed mainly to the preservative (benzalkonium chloride (BAC)) constituent of cosmetic product material (CPM). Transport of CPM from an external environment to any location on the ocular surface, essentially precedes the adverse interactions occurring at the location, and the control of these transport modes is therefore of clinical relevance. The inter-transport of CPM across the TF occurs due to both diffusion and drift processes. Diffusion of neutral species is driven by concentration gradients, and the drift of cationic BAC is influenced by the inherent electric field; determined by the distribution of the various ions secreted into the aqueous layer, and the negative glycocalyx charge at the mucin layer. In the presence of mucin deficiency, the corneal epithelium is exposed to invasion by both incident BAC and lipophilic species. The transport of cationic BAC across the TF may be controlled by regulating the secretion of various electrolytes at the lacrimal gland. This is of clinical significance in reducing corneal epithelial adverse effects. However, the risks of adverse effects at the corneal surface due to invasion by the lipophilic species remain. Patients with mucin deficiency, and especially those on eye ointment/drops medication, should be discouraged from using cosmetics in a way likely to contaminate the TF.

  14. Static and Dynamic Measurement of Ocular Surface Temperature in Dry Eyes.

    PubMed

    Tan, Li Li; Sanjay, Srinivasan; Morgan, Philip B

    2016-01-01

    Purpose. To study ocular surface temperature (OST) in dry eyes by static and dynamic measures. Methods. OST was recorded on 62 dry eyes and 63 age- and sex-matched controls. Static measures were study of absolute OST at t = 0, 5, and 10 s after eye opening. Dynamic measures were study of mean change and net change in OST over 10 s of sustained eye opening. Ten OST indices studied were temperatures of the geometric center of the cornea (GCC), extreme temporal (T1) and nasal conjunctiva (T4), midtemporal (CT) and nasal conjunctiva (CN), temporal (LT) and nasal (LN) limbus, and mean (MOST), maximum (Max T), and minimum (Min T) temperatures of the region of interest. Results. For static measures, dry eyes recorded significantly lower GCC, MOST, Min T, Max T, T4, CT, LT, LN, and CN. For dynamic measures, dry eyes had significantly steeper regression line of mean change (corresponding to greater net change) for Max T 5 s onward and T4 at 3 s onward. Conclusions. Both static and dynamic measures of the OST were valuable and can be used as clinical tool to assess dry eye.

  15. Thermal analysis of dry eye subjects and the thermal impulse perturbation model of ocular surface.

    PubMed

    Zhang, Aizhong; Maki, Kara L; Salahura, Gheorghe; Kottaiyan, Ranjini; Yoon, Geunyoung; Hindman, Holly B; Aquavella, James V; Zavislan, James M

    2015-03-01

    In this study, we explore the usage of ocular surface temperature (OST) decay patterns to distinguished between dry eye patients with aqueous deficient dry eye (ADDE) and meibomian gland dysfunction (MGD). The OST profiles of 20 dry eye subjects were measured by a long-wave infrared thermal camera in a standardized environment (24 °C, and relative humidity (RH) 40%). The subjects were instructed to blink every 5 s after 20 ∼ 25 min acclimation. Exponential decay curves were fit to the average temperature within a region of the central cornea. We find the MGD subjects have both a higher initial temperature (p < 0.022) and a higher asymptotic temperature (p < 0.007) than the ADDE subjects. We hypothesize the temperature difference among the subpopulations is due to tear volume and heat transfer mechanisms. To study the validity of our claim, we develop a mathematical model, referred to as the thermal impulse perturbation (TIP) model. We conclude that long-wave-infrared thermal imaging is a plausible tool in assisting with the classification of dry eye patient.

  16. Static and Dynamic Measurement of Ocular Surface Temperature in Dry Eyes

    PubMed Central

    Sanjay, Srinivasan; Morgan, Philip B.

    2016-01-01

    Purpose. To study ocular surface temperature (OST) in dry eyes by static and dynamic measures. Methods. OST was recorded on 62 dry eyes and 63 age- and sex-matched controls. Static measures were study of absolute OST at t = 0, 5, and 10 s after eye opening. Dynamic measures were study of mean change and net change in OST over 10 s of sustained eye opening. Ten OST indices studied were temperatures of the geometric center of the cornea (GCC), extreme temporal (T1) and nasal conjunctiva (T4), midtemporal (CT) and nasal conjunctiva (CN), temporal (LT) and nasal (LN) limbus, and mean (MOST), maximum (Max T), and minimum (Min T) temperatures of the region of interest. Results. For static measures, dry eyes recorded significantly lower GCC, MOST, Min T, Max T, T4, CT, LT, LN, and CN. For dynamic measures, dry eyes had significantly steeper regression line of mean change (corresponding to greater net change) for Max T 5 s onward and T4 at 3 s onward. Conclusions. Both static and dynamic measures of the OST were valuable and can be used as clinical tool to assess dry eye. PMID:27433352

  17. Borneol Is a TRPM8 Agonist that Increases Ocular Surface Wetness

    PubMed Central

    Chen, Gui-Lan; Lei, Ming; Zhou, Lu-Ping; Zou, Fangdong

    2016-01-01

    Borneol is a compound widely used in ophthalmic preparations in China. Little is known about its exact role in treating eye diseases. Here we report that transient receptor potential melastatin 8 (TRPM8) channel is a pharmacological target of borneol and mediates its therapeutic effect in the eyes. Ca2+ measurement and electrophysiological recordings revealed that borneol activated TRPM8 channel in a temperature- and dose-dependent manner, which was similar to but less effective than the action of menthol, an established TRPM8 agonist. Borneol significantly increased tear production in guinea pigs without evoking nociceptive responses at 25°C, but failed to induce tear secretion at 35°C. In contrast, menthol evoked tearing response at both 25 and 35°C. TRPM8 channel blockers N-(3-Aminopropyl)-2-[(3-methylphenyl)methoxy]-N-(2-thienylmethyl)benzamide hydrochloride (AMTB) and N-(4-tert-butylphenyl)-4-(3-chloropyridin-2-yl)piperazine-1-carboxamide (BCTC) abolished borneol- and menthol-induced tear secretion. Borneol at micromolar concentrations did not affect the viability of human corneal epithelial cells. We conclude that borneol can activate the cold-sensing TRPM8 channel and modestly increase ocular surface wetness, which suggests it is an active compound in ophthalmic preparations and particularly useful in treating dry eye syndrome. PMID:27448228

  18. Coupling fluid and solute dynamics within the ocular surface tear film: a modelling study of black line osmolarity.

    PubMed

    Zubkov, V S; Breward, C J W; Gaffney, E A

    2012-09-01

    We present a mathematical model describing the spatial distribution of tear film osmolarity across the ocular surface of a human eye during one blink cycle, incorporating detailed fluid and solute dynamics. Based on the lubrication approximation, our model comprises three coupled equations tracking the depth of the aqueous layer of the tear film, the concentration of the polar lipid, and the concentration of physiological salts contained in the aqueous layer. Diffusive boundary layers in the salt concentration occur at the thinnest regions of the tear film, the black lines. Thus, despite large Peclet numbers, diffusion ameliorates osmolarity around the black lines, but nonetheless is insufficient to eliminate the build-up of solute in these regions. More generally, a heterogeneous distribution of solute concentration is predicted across the ocular surface, indicating that measurements of lower meniscus osmolarity are not globally representative, especially in the presence of dry eye. Vertical saccadic eyelid motion can reduce osmolarity at the lower black line, raising the prospect that select eyeball motions more generally can assist in alleviating tear film hyperosmolarity. Finally, our results indicate that measured evaporative rates will induce excessive hyperosmolarity at the black lines, even for the healthy eye. This suggests that further evaporative retardation at the black lines, for instance due to the cellular glycocalyx at the ocular surface or increasing concentrations of mucus, will be important for controlling hyperosmolarity as the black line thins.

  19. An engineered human conjunctival-like tissue to study ocular surface inflammatory diseases.

    PubMed

    García-Posadas, Laura; Soriano-Romaní, Laura; López-García, Antonio; Diebold, Yolanda

    2017-01-01

    The aim of this study was to develop a three-dimensional model of the human conjunctiva that can be used to perform physiology and pathophysiology experiments. Fibrin-based matrices (derived from human plasma or plasma cryoprecipitate) were used as scaffolds, and primary cells were obtained from conjunctival tissue. Conjunctival constructs were analyzed by immunofluorescent staining and scanning electron microscopy and cell proliferation was measured with alamarBlue® assay. After characterizing the constructs, four different experimental conditions were analyzed in cryoprecipitate matrices: controls, air-lifted cultures (to increase cell stratification), partially desiccated cultures (to mimic dry eye disease), and IL-13-treated cultures (to mimic allergy). Constructs were stained with hematoxylin/eosin to observe changes in morphology. High molecular weight glycoconjugates were identified by HPA staining. MUC5AC and IL-6 secretion was evaluated by ELISA. The fibrin-based matrices supported conjunctival cell growth. Epithelial cells grew on the surface of the scaffolds and underwent stratification that increased over time. These cells had microvilli, which suggests cell polarization and functionality. Fibroblasts were integrated in the scaffold and showed elongated shape. Compared to controls, air-lifted construct had increased epithelial stratification and upregulated MUC5AC secretion. Increased MUC5AC secretion also occurred in partially desiccated and IL-13-treated cultures. The inflammatory status of cells was evaluated by IL-6 levels which were increased in air-lifted and partially desiccated cultures, but not in IL-13-treated ones. In conclusion, we have developed a new three-dimensional model of human conjunctiva that can be used to study ocular surface inflammatory diseases.

  20. An engineered human conjunctival-like tissue to study ocular surface inflammatory diseases

    PubMed Central

    García-Posadas, Laura; Soriano-Romaní, Laura; López-García, Antonio; Diebold, Yolanda

    2017-01-01

    The aim of this study was to develop a three-dimensional model of the human conjunctiva that can be used to perform physiology and pathophysiology experiments. Fibrin-based matrices (derived from human plasma or plasma cryoprecipitate) were used as scaffolds, and primary cells were obtained from conjunctival tissue. Conjunctival constructs were analyzed by immunofluorescent staining and scanning electron microscopy and cell proliferation was measured with alamarBlue® assay. After characterizing the constructs, four different experimental conditions were analyzed in cryoprecipitate matrices: controls, air-lifted cultures (to increase cell stratification), partially desiccated cultures (to mimic dry eye disease), and IL-13-treated cultures (to mimic allergy). Constructs were stained with hematoxylin/eosin to observe changes in morphology. High molecular weight glycoconjugates were identified by HPA staining. MUC5AC and IL-6 secretion was evaluated by ELISA. The fibrin-based matrices supported conjunctival cell growth. Epithelial cells grew on the surface of the scaffolds and underwent stratification that increased over time. These cells had microvilli, which suggests cell polarization and functionality. Fibroblasts were integrated in the scaffold and showed elongated shape. Compared to controls, air-lifted construct had increased epithelial stratification and upregulated MUC5AC secretion. Increased MUC5AC secretion also occurred in partially desiccated and IL-13-treated cultures. The inflammatory status of cells was evaluated by IL-6 levels which were increased in air-lifted and partially desiccated cultures, but not in IL-13-treated ones. In conclusion, we have developed a new three-dimensional model of human conjunctiva that can be used to study ocular surface inflammatory diseases. PMID:28248962

  1. Ocular disease and driving.

    PubMed

    Wood, Joanne M; Black, Alex A

    2016-09-01

    As the driving population ages, the number of drivers with visual impairment resulting from ocular disease will increase given the age-related prevalence of ocular disease. The increase in visual impairment in the driving population has a number of implications for driving outcomes. This review summarises current research regarding the impact of common ocular diseases on driving ability and safety, with particular focus on cataract, glaucoma, age-related macular degeneration, hemianopia and diabetic retinopathy. The evidence considered includes self-reported driving outcomes, driving performance (on-road and simulator-based) and various motor vehicle crash indices. Collectively, this review demonstrates that driving ability and safety are negatively affected by ocular disease; however, further research is needed in this area. Older drivers with ocular disease need to be aware of the negative consequences of their ocular condition and in the case where treatment options are available, encouraged to seek these earlier for optimum driving safety and quality of life benefits.

  2. HLA-DR EXPRESSION AS A BIOMARKER OF INFLAMMATION FOR MULTICENTER CLINICAL TRIALS OF OCULAR SURFACE DISEASE

    PubMed Central

    Epstein, Seth P.; Gadaria-Rathod, Neha; Wei, Yi; Maguire, Maureen G.; Asbell, Penny A.

    2014-01-01

    There are currently no validated minimally invasive objective metrics for the classification and evaluation of ocular surface diseases and/or for evaluating treatment efficacy. We thus sought to establish a standardized methodology for determining the relative amount of the inflammatory biomarker HLA-DR on the ocular surface and to evaluate the precision, reliability and repeatability of its use for large multicenter clinical trials and translational research studies of ocular surface disease. Multiple studies were conducted to establish a Standard Operating Procedure (SOP) for utilizing HLA-DR expression as a minimally invasive, objective, ocular surface inflammatory biomarker. The established SOPs provide specific guidelines for HLA-DR collection and analysis, in order to incorporate it reliably into multicenter clinical trials and/or translational research. Duplicate cell samples from impression cytology (IC) samples of both normal and dry eye individuals were collected and split to assess repeatability (between the splits and between the duplicate samples). To determine storage capability, one duplicate was stained immediately and the other after 30 days cold storage. To demonstrate the feasibility of the use of the SOP for a multicenter clinical trial, clinicians out-of-state were trained to collect IC samples, and the samples shipped to our Biomarker Laboratory, logged, processed and analyzed. Demonstration of the ability to incorporate of IC into a randomized double masked clinical trial of dry eye disease (DED) was performed. In all cases, processing and analyses were performed by a masked independent observer. The validity/viability of the SOPs was established by demonstrating that: 1) sufficient numbers of cells can be collected via IC; 2) the precision/repeatability of the relative biomarker expression quantified in samples; 3) personnel at distant sites can be taught to collect, store and ship samples successfully; 4) samples can be stored for up to 30

  3. Comparison of Early Changes in Ocular Surface and Inflammatory Mediators between Femtosecond Lenticule Extraction and Small-Incision Lenticule Extraction

    PubMed Central

    Zhang, Chi; Ding, Hui; He, Miao; Liu, Lina; Liu, Liangping; Li, Gang; Niu, Bing; Zhong, Xingwu

    2016-01-01

    Purpose To evaluate the short-term changes in ocular surface measures and tear inflammatory mediators after femtosecond lenticule extraction (FLEx) and small-incision lenticule extraction (SMILE) procedures. Methods Eighteen subjects (18 eyes) underwent FLEx and 23 subjects (23 eyes) underwent SMILE in this single-center and prospective study. Central corneal sensitivity, Schirmer I test (SIT), noninvasive tear breakup time (NI-TBUT), tear meniscus height, corneal fluorescein (FL) staining, and ocular surface disease index (OSDI) were assessed in all patients. Concentrations of interleukin-1α (IL-1α), tumor necrosis factor-α (TNF-α), nerve growth factor (NGF), interferon-γ (IFN-γ), transforming growth factor-β1 (TGF-β1) and matrix metalloproteinase-9 (MMP-9) in collected tears were measured by multiplex antibody microarray. Results Central corneal sensitivity was reduced in both groups, but the scores in the SMILE group were higher than those in the FLEx group at all time points postoperatively (P<0.01). Lower FL scores and longer NI-BUT were observed in the SMILE group 1 week after surgery (P<0.05). OSDI scores in both groups increased rapidly at 1 day and 1 week postoperatively, then returned to their preoperative levels within 1 month (P<0.05). There were no significant differences in SIT or tear meniscus height between the two groups. Lower and faster recovery of tear NGF, TGF-β1 and IL-1α concentration were found in the SMILE group compared to the FLEx group postoperatively. No significant difference was found in tear TNF-α, IFN-γ and MMP-9 for either group before or after surgery. Tear NGF, TGF-β1 and IL-1α show a correlation with ocular surface changes after FLEx or SMILE surgery. Conclusion SMILE has superiority over FLEx in early ocular surface changes and NGF, TGF-β1 and IL-1α may contribute to the process of ocular surface recovery. Trial Registration ClinicalTrials.gov NCT02540785 PMID:26937680

  4. Association of human papilloma virus with pterygia and ocular-surface squamous neoplasia

    PubMed Central

    Di Girolamo, N

    2012-01-01

    There are more microorganisms that colonize the human body than resident cells; some are commensal whereas others are pathogenic. Pathogenic microorganisms are sensed by the innate or adaptive immune system, an immune response is initiated, and the infection is often cleared. Some microorganisms have developed strategies to evade immune defenses, ensuring their long-term survival with potentially devastating consequences for the host. Approximately 18% of all cancers can be attributed to infective agents; the most common being Helicobacter pylori, Human papilloma virus (HPV) and Hepatitis B and C virus in causing stomach, cervical and liver carcinoma, respectively. This review focuses on whether HPV infection is necessary for initiating pterygia, a common benign condition and ocular-surface squamous neoplasia (OSSN), a rare disease with metastatic potential. The search engine PubMed was used to identify articles from the literature related to HPV and pterygium or conjunctival neoplasia. From 34 investigations that studied HPV in pterygia and OSSN, a prevalence rate of 18.6% (136/731) and 33.8% (144/426), respectively, was recorded. The variation in HPV prevalence (0–100%) for both disease groups may have arisen from study-design faults and the techniques used to identify the virus. Overall, the data suggest that HPV is not necessary for initiating either condition but may be a co-factor in susceptible hosts. Currently, over 60 million people worldwide have been immunized with HPV vaccines, but any effect on pterygium and OSSN development may not be known for some time as these lesions can evolve over decades or occur in older individuals. PMID:22134594

  5. Thermography in ocular inflammation

    PubMed Central

    Kawali, Ankush A

    2013-01-01

    Background and Objectives: The purpose of this study was to evaluate ocular inflammatory and non-inflammatory conditions using commercially available thermal camera. Materials and Methods: A non-contact thermographic camera (FLIR P 620) was used to take thermal pictures of seven cases of ocular inflammation, two cases of non-inflammatory ocular pathology, and one healthy subject with mild refractive error only. Ocular inflammatory cases included five cases of scleritis, one case of postoperative anterior uveitis, and a case of meibomian gland dysfunction with keratitis (MGD-keratitis). Non-inflammatory conditions included a case of conjunctival benign reactive lymphoid hyperplasia (BRLH) and a case of central serous chorio-retinopathy. Thermal and non-thermal photographs were taken, and using analyzing software, the ocular surface temperature was calculated. Results: Patient with fresh episode of scleritis revealed high temperature. Eyes with MGD-keratitis depicted lower temperature in clinically more affected eye. Conjunctival BRLH showed a cold lesion on thermography at the site of involvement, in contrast to cases of scleritis with similar clinical presentation. Conclusion: Ocular thermal imaging is an underutilized diagnostic tool which can be used to distinguish inflammatory ocular conditions from non-inflammatory conditions. It can also be utilized in the evaluation of tear film in dry eye syndrome. Its applications should be further explored in uveitis and other ocular disorders. Dedicated “ocular thermographic” camera is today's need of the hour. PMID:24347863

  6. Ocular Rosacea

    MedlinePlus

    ... Staff Ocular rosacea is inflammation that causes redness, burning and itching of the eyes. It often develops ... symptoms of ocular rosacea may include: Dry eyes Burning or stinging in the eyes Itchy eyes Grittiness ...

  7. Differential Expression of Stem Cell Markers in Ocular Surface Squamous Neoplasia

    PubMed Central

    Mishra, Dilip Kumar; Veena, Uppala; Kaliki, Swathi; Kethiri, Abhinav Reddy; Sangwan, Virender S.; Ali, Mohammed Hasnat; Naik, Milind N.; Singh, Vivek

    2016-01-01

    Ocular Surface Squamous Neoplasm (OSSN) is the neoplasia arising from the conjunctiva, cornea and limbus. OSSN ranges from mild, moderate, severe dysplasia, carcinoma in situ (CIS) to squamous cell carcinoma (SCC). Recent findings on cancer stem cells theory indicate that population of stem-like cell as in neoplasia determines its heterogeneity and complexity leading to varying tumor development of metastatic behavior and recurrence. Cancer stem cell markers are not much explored in the cases of OSSN. In the present study, we aim to evaluate the expression of stem cells using stem cell markers mainly p63, ABCG2, c-KIT (CD117) and CD44 in OSSN tissue, which could have prognostic significance. The present study tries for the first time to explore expression of these stem markers in the cases of OSSN. These cases are subdivided into two groups. One group comprises of carcinoma in situ (n = 6) and the second group comprises of invasive carcinoma (n = 6). The mean age at presentation was 52 years; with 53 years for CIS group and 52 years for SCC group. From each group section from the paraffin block were taken for the IHC staining of p63, c-Kit, ABCG2 and CD44. Our experiments show high expression of P63 and CD44 in the cases of CIN and SCC. Both CIS and SCC displayed positive staining with p63, with more than 80% cells staining positive. However minimal expression of c-kit in both CIN and SCC. But surprisingly we got high expression of ABCG2 in cases of carcinoma in situ as compared to that of invasive squamous cell carcinoma. More than 50% of cells showed CD44 positivity in both CIS and SCC groups. Our results show for the first time that these four stem cells especially the limbal epithelium stem cells play a vital role in the genesis of OSSN but we need to explore more cases before establishing its clinical and biological significance. PMID:27584160

  8. Surgical versus medical treatment of ocular surface squamous neoplasia: A cost comparison

    PubMed Central

    Moon, Christina S.; Nanji, Afshan A.; Galor, Anat; McCollister, Kathryn E.; Karp, Carol L.

    2016-01-01

    Purpose The objective of this study was to compare the cost associated with surgical versus interferon (IFNα2b) treatment for ocular surface squamous neoplasia (OSSN). Design A matched, case-control study. Participants Ninety-eight patients with OSSN; 49 of whom were treated surgically and 49 of whom were treated medically. Methods Patients with OSSN treated with IFNα2b were matched to surgery patients based on age and date of treatment initiation. Financial cost to the patient was calculated using two different methods (hospital billing and Medicare allowable charges) and compared between the two groups. These fees included physician fees (clinic, pathology, anesthesia, and surgery), facility fees (clinic, pathology, and operating room), and medication costs. Time invested by patients was calculated in terms of number of visits to the hospital and compared between the two groups. Parking costs, transportation, caregiver wages, and lost wages were not considered in our analysis. Main outcome measures Number of clinic visits and cost of therapy as represented by both hospital charges and Medicare allowable charges. Results When considering cost in terms of time, the medical group had an average of 2 more actual and imputed number of visits over 1 year compared to the surgical group. Cost as represented by hospital charges was higher in the surgical group (mean $17,598, SD $7,624) when compared to the IFNα2b group (mean $4,986, SD $2,040). However, cost between the two groups was comparable when calculated based on Medicare allowable charges (surgical group: mean $3,528, SD $1,610; medical group: mean $2,831, SD $1,082; P = 1.00). The highest cost category in the surgical group was the excisional biopsy (Hospital billing $17,598; Medicare allowable $3,528) while the highest cost in the medical group was interferon ($1,172 for drops, average 8.0 bottles; $370 for injections, average 5.4 injections). Conclusion Our data in this group of patients previously

  9. Presence or absence of ocular surface inflammation directs clinical and therapeutic management of dry eye

    PubMed Central

    Sambursky, Robert

    2016-01-01

    Background The presence of clinically significant inflammation has been confirmed in the tears of 40%–65% of patients with symptoms of dry eye. Ocular surface inflammation may lead to tear film instability, epithelial cell irregularities, and permeability, resulting in chronic symptomatic pain and fluctuating vision as well as negative surgical outcomes. Patients and methods A retrospective single center medical chart review of 100 patients was conducted. All patients were tested with the InflammaDry test to determine if patients exhibited elevated levels of matrix metalloproteinase 9 (MMP-9). InflammaDry-positive patients were started on a combination of cyclosporine 0.05% twice daily, 2,000–4,000 mg oral omega-3 fatty acids, and frequent artificial tear replacement. InflammaDry-negative patients were started on 2,000–4,000 mg of oral omega-3 fatty acids and frequent artificial tear replacement. Each patient was retested at ~90 days. A symptom questionnaire was performed at the initial visit and at 90 days. Results 60% of the patients with dry eye symptoms tested positive for elevated MMP-9 at the initial visit. 78% of all patients returned for follow-up at ~90 days including 80% (48/60) of the previously InflammaDry-positive patients and 75% (30/40) of the previously InflammaDry-negative patients. A follow-up symptom questionnaire reported at least 75% symptomatic improvement in 65% (31/48) of the originally InflammaDry-positive patients and in 70% (21/30) of the initially InflammaDry-negative patients. Symptomatic improvement of at least 50% was reported in 85% (41/48) of previously InflammaDry-positive patients and 86% (26/30) of previously InflammaDry-negative patients. Following treatment, 54% (26/48) of previously InflammaDry-positive patients converted to a negative InflammaDry result. Conclusion Identifying which symptomatic dry eye patients have underlying inflammation may predict patient responses to treatment and influence clinical management

  10. Dynamic ocular surface and lacrimal gland changes induced in experimental murine dry eye.

    PubMed

    Xiao, Bing; Wang, Yu; Reinach, Peter S; Ren, Yueping; Li, Jinyang; Hua, Shanshan; Lu, Huihui; Chen, Wei

    2015-01-01

    Dry eye disease can be a consequence of lacrimal gland insufficiency in Sjögren's Syndrome or increased tear film evaporation despite normal lacrimal gland function. To determine if there is a correlation between severity effects in these models and underlying pathophysiological responses, we compared the time dependent changes in each of these parameters that occur during a 6 week period. Dry eye was induced in 6-week-old female C57BL/6 mice by exposing them to an Intelligently Controlled Environmental System (ICES). Sixty mice were housed in ICES for 1, 2, 4 and 6 weeks respectively. Twelve were raised in normal environment and received subcutaneous injections of scopolamine hydrobromide (SCOP) 3 times daily for 5 days. Another sixty mice were housed in a normal environment and received no treatment. Corneal fluorescein staining along with corneal MMP-9 and caspase-3 level measurements were performed in parallel with the TUNEL assay. Interleukin-17(IL-17), IL-23, IL-6, IL-1, TNF-α, IFN-γ and TGF-β2 levels were estimated by real-time PCR measurements of conjunctival and lacrimal gland samples (LGs). Immunohistochemistry of excised LGs along with flow cytometry in cervical lymph nodes evaluated immune cell infiltration. Light and transmission electron microscopy studies evaluated LGs cytoarchitectural changes. ICES induced corneal epithelial destruction and apoptosis peaked at 2 weeks and kept stable in the following 4 weeks. In the ICES group, lacrimal gland proinflammatory cytokine level increases were much lower than those in the SCOP group. In accord with the lower proinflammatory cytokine levels, in the ICES group, lacrimal gland cytosolic vesicular density and size exceeded that in the SCOP group. ICES and SCOP induced murine dry eye effects became progressively more severe over a two week period. Subsequently, the disease process stabilized for the next four weeks. ICES induced local effects in the ocular surface, but failed to elicit lacrimal gland

  11. Toluidine Blue 0.05% Vital Staining for Diagnosis of Ocular Surface Squamous Neoplasia in Kenya

    PubMed Central

    Gichuhi, Stephen; Macharia, Ephantus; Kabiru, Joy; M’bongo Zindamoyen, Alain; Rono, Hilary; Ollando, Ernest; Wanyonyi, Leonard; Wachira, Joseph; Munene, Rhoda; Onyuma, Timothy; Jaoko, Walter G.; Sagoo, Mandeep S.; Weiss, Helen A.; Burton, Matthew J.

    2017-01-01

    Importance Clinical features are unreliable for distinguishing Ocular Surface Squamous Neoplasia (OSSN) from benign conjunctival lesions. Objective To evaluate the adverse effects, accuracy and inter-observer variation of Toluidine Blue 0.05% vital staining in distinguishing OSSN, confirmed by histopathology, from other conjunctival lesions. Design, Setting and Participants Cross-sectional study in Kenya from July 2012 through July 2014 of 418 adults with suspicious conjunctival lesions. Pregnant and breastfeeding women were excluded. Exposures Comprehensive ophthalmic slit-lamp examination was conducted. Vital staining with Toluidine Blue 0.05% aqueous solution was performed before surgery. Initial safety testing was conducted on large tumours scheduled for exenteration looking for corneal toxicity on histology before testing smaller tumours. We asked about pain or discomfort after staining and evaluated the cornea at the slit lamp for epithelial defects. Lesions were photographed before and after staining. Diagnosis was confirmed by histopathology. Six examiners assessed photographs from a sub-set of 100 consecutive participants for staining and made a diagnosis of OSSN vs Non-OSSN. Main Outcomes and Measures Staining was compared with histopathology to estimate sensitivity, specificity and predictive values. Adverse effects were enumerated. Inter-observer agreement was estimated using the kappa statistic (k). Results 143/419 (34%) participants had OSSN by histopathology. The median (interquartile range) age of the 419 was 37 (32-45) years and 278 (66%) were female. 322/419 participants had positive staining while 2/419 were equivocal. There was no histological evidence of corneal toxicity. Mild discomfort was reported by 88 (21%) and mild superficial punctate keratopathy seen in 7 (1.7%).For detecting OSSN, Toluidine blue had a sensitivity of 92% (95%CI, 87%-96%), specificity 31% (95%CI, 25%-36%), positive predictive value 41% (95%CI, 35%-46%), and negative

  12. Antimicrobial susceptibility and minimal inhibitory concentration of Pseudomonas aeruginosa isolated from septic ocular surface disease in different animal species

    PubMed Central

    Leigue, L.; Montiani-Ferreira, F.; Moore, B.A.

    2016-01-01

    The purpose of this study was to evaluate the antibiotic susceptibility profile of Pseudomonas aeruginosa isolated from different animal species with septic ocular surface disease. Sixteen strains of P. aeruginosa were isolated from different species of animals (dog, cat, horse, penguin and brown bear) with ocular surface diseases such as conjunctivitis, keratocojnuctivits sicca and ulcerative keratitis. These isolates were tested against 11 different antimicrobials agents using the Kirby-Bauer disk-diffusion method. Minimum inhibitory concentrations (MICs) were determined using E-tests for two antibiotics (tobramycin and ciprofloxacin) commonly used in veterinary ophthalmology practice. Imipenem was the most effective antibiotic, with 100% of the strains being susceptible, followed by amikacin (87.5%), gentamicin, norfloxacin, gatifloxacin and polymyxin (both with 81.5%of susceptibility). MIC90 of ciprofloxacin was 2 µg/ml and the values found ranged from 0.094 µg/ml to 32 µg/ml. For tobramycin, MIC90 was 32 µg/ml and ranged from 0.25 µg/ml to 256 µg/ml. The most effective in vitro antibiotic tested against P. aeruginosa in this study was imipenem, followed by amikacin. The 3 mg/ml eye drops commercially available ciprofloxacin presentations were in vitro effective against all strains tested in this study if applied up to 4 hours after instillation. Whereas for tobramycin the 3 mg/ml eye drops commercial presentations were not in vitro effective against some strains isolated in this study. Thus for ocular infections with P. aeruginosa when using tobramycin the ideal recommendation would be to either use eye drops with higher concentrations or decrease the frequency intervals from four to a minimum of every two hours. PMID:27928519

  13. Intracellular trafficking of hyaluronic acid-chitosan oligomer-based nanoparticles in cultured human ocular surface cells

    PubMed Central

    Contreras-Ruiz, Laura; de la Fuente, María; Párraga, Jenny E.; López-García, Antonio; Fernández, Itziar; Seijo, Begoña; Sánchez, Alejandro; Calonge, Margarita

    2011-01-01

    Purpose Nanoparticles are a promising alternative for ocular drug delivery, and our group has proposed that they are especially suited for ocular mucosal disorders. The goal of the present study was to determine which internalization pathway is used by cornea-derived and conjunctiva-derived cell lines to take up hyaluronic acid (HA)-chitosan oligomer (CSO)-based nanoparticles (HA-CSO NPs). We also determined if plasmids loaded onto the NPs reached the cell nucleus. Methods HA-CSO NPs were made of fluoresceinamine labeled HA and CSO by ionotropic gelation and were conjugated with a model plasmid DNA for secreted alkaline phosphatase. Human epithelial cell lines derived from the conjunctiva and the cornea were exposed to HA-CSO NPs for 1 h and the uptake was investigated in living cells by fluorescence microscopy. The influence of temperature and metabolic inhibition, the effect of blocking hyaluronan receptors, and the inhibition of main endocytic pathways were studied by fluorometry. Additionally, the metabolic pathways implicated in the degradation of HA-CSO NPs were evaluated by lysosome identification. Results There was intracellular localization of plasmid-loaded HACSO NPs in both corneal and conjunctival cells. The intracellular presence of NPs diminished with time. HA-CSO NP uptake was significantly reduced by inhibition of active transport at 4 °C and by sodium azide. Uptake was also inhibited by blocking hyaluronan receptors with anti-CD44 Hermes-1 antibody, by excess HA, and by filipin, an inhibitor of caveolin-dependent endocytosis. HA-CSO NPs had no effect on cell viability. The transfection efficiency of the model plasmid was significantly higher in NP treated cells than in controls. Conclusions HA-CSO NPs were internalized by two different ocular surface cell lines by an active transport mechanism. The uptake was mediated by hyaluronan receptors through a caveolin-dependent endocytic pathway, yielding remarkable transfection efficiency. Most of HA

  14. The surface area of soil organic matter

    USGS Publications Warehouse

    Chiou, C.T.; Lee, J.-F.; Boyd, S.A.

    1990-01-01

    The previously reported surface area for soil organic matter (SOM) of 560-800 m2/g as determined by the ethylene glycol (EG) retention method was reexamined by the standard BET method based on nitrogen adsorption at liquid nitrogen temperature. Test samples consisted of two high organic content soils, a freeze-dried soil humic acid, and an oven-dried soil humic acid. The measured BET areas for these samples were less than 1 m2/g, except for the freeze-dried humic acid. The results suggest that surface adsorption of nonionic organic compounds by SOM is practically insignificant in comparison to uptake by partition. The discrepancy between the surface areas of SOM obtained by BET and EG methods was explained in terms of the 'free surface area' and the 'apparent surface area' associated with these measurements.The previously reported surface area for soil organic matter (SOM) of 560-800 m2/g as determined by the ethylene glycol (EG) retention method was reexamined by the standard BET method based on nitrogen adsorption at liquid nitrogen temperature. Test samples consisted of two high organic content soils, a freeze-dried soil humic acid, and an oven-dried soil humic acid. The measured BET areas for these samples were less than 1 m2/g, except for the freeze-dried humic acid. The results suggest that surface adsorption of nonionic organic compounds by SOM is practically insignificant in comparison to uptake by partition. The discrepancy between the surface areas of SOM obtained by BET and EG methods was explained in terms of the 'free surface area' and the 'apparent surface area' associated with these measurements.

  15. Coal dust contiguity-induced changes in the concentration of TNF-alpha and NF-kappa B p65 on the ocular surface.

    PubMed

    Sun, Zhaoyi; Hong, Jing; Liu, Zaiying; Jin, Xiudong; Gu, Changhong

    2009-01-01

    To observe the influence of coal dust on ocular surface of coal miners and rabbits with coal dust contiguity on expression TNF-alpha and NF-kappa Bp65 and dry eye occurrence. Tear production, BUT and lysozyme decreased for coal miners and rabbits with coal dust contiguity. Expression TNF-alpha and NF-kappa Bp65 in ocular surface were determined. Results showed tear production, BUT and lysozyme decreased for coal miners and rabbits with coal dust contiguity. Coal dust exposure was linked to development of xerophthalmia, and induced a higher expression of NF-kappa B p65 and TNF-alpha perhaps as a mechanism to resist coal dust ocular surface injury.

  16. Reducing bacterial contamination inside fluid catch bag in 25-gauge vitrectomy by use of 0.25 % povidone-iodine ocular surface irrigation.

    PubMed

    Shimada, Hiroyuki; Nakashizuka, Hiroyuki; Hattori, Takayuki; Kitagawa, Yorihisa; Manabe, Ayumu; Otani, Kuon; Yuzawa, Mitsuko

    2013-02-01

    To examine the bacterial detection rate in infusion fluid collected inside the fluid catch bag during 25-gauge (25G) vitrectomy when the ocular surface was irrigated with infusion fluid or 0.25 % povidone-iodine. Two groups using different fluids for ocular surface irrigation during 25G vitrectomy were studied. Fifty-five consecutive eyes received ocular surface irrigation with infusion fluid (IF group) and 52 consecutive eyes with 0.25 % povidone-iodine (PI group). Samples of ocular surface fluid were collected at the beginning of surgery and samples of infusion fluid inside the fluid catch bag were collected at the end of surgery for bacteriological cultures. At the beginning of surgery, the bacterial detection rates in ocular surface fluid samples were 5.8 % (3 of 52 eyes) in the IF group and 7.7 % (4 of 52 eyes) in the PI group, with no significant difference (P = 0.6955). At the end of surgery, the bacterial detection rates in infusion fluid collected inside the fluid catch bag were 23.1 % (12 of 52 eyes) in the IF group and 3.8 % (2 of 52 eyes) in the PI group, with a significant difference (P = 0.0041). No endophthalmitis occurred in either group. These results demonstrate the risk of bacterial contamination when surgical instruments fall accidentally into the fluid catch bag during conventional 25G vitrectomy. Irrigating the ocular surface with 0.25 % povidone-iodine instead of infusion fluid significantly reduces the bacterial contamination rate in the fluid catch bag.

  17. Evaluation of ocular surface temperature and retrobulbar haemodynamics by infrared thermography and colour Doppler imaging in patients with glaucoma

    PubMed Central

    Galassi, Fernando; Giambene, Barbara; Corvi, Andrea; Falaschi, Giacomo

    2007-01-01

    Background Ocular surface temperature (OST) could berelated to retrobulbar haemodynamics in patients with glaucoma. Aims To compare OST measurements in patients with glaucoma and healthy controls, and to investigate the correlation between OST, intraocular pressure (IOP) and retrobulbar haemodynamics in patients with glaucoma. Methods 32 patients with primary open‐angle glaucoma (POAG) and 40 controls were included in the study. The parameters considered both in patients with POAG and in controls were IOP and OST values measured by infrared ocular thermography. Colour Doppler imaging was used to determine haemodynamic parameters in ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (SPCAs) in patients with POAG. Results OST values were significantly lower in patients with POAG than in controls (p<0.001). OST was negatively related with resistivity index of OA (p<0.001), CRA (p = 0.001) and SPCAs (p<0.001), and positively related with end‐diastolic velocity of OA (p = 0.02) and SPCAs (p = 0.05). Conclusion This study suggested that OST could be a marker of impaired retrobulbar haemodynamics in patients with glaucoma. PMID:17314146

  18. Surface area coefficients for airship envelopes

    NASA Technical Reports Server (NTRS)

    Diehl, W S

    1922-01-01

    In naval architecture, it is customary to determine the wetted surface of a ship by means of some formula which involves the principal dimensions of the design and suitable constants. These formulas of naval architecture may be extended and applied to the calculation of the surface area of airship envelopes by the use of new values of the constants determined for this purpose. Surface area coefficients were calculated from the actual dimensions, surfaces, and volumes of 52 streamline bodies, which form a series covering the entire range of shapes used in the present aeronautical practice.

  19. The IMPACT study: a prospective evaluation of the effects of cyclosporine ophthalmic emulsion 0.05% on ocular surface staining and visual performance in patients with dry eye

    PubMed Central

    Stonecipher, Karl G; Torkildsen, Gail L; Ousler, George W; Morris, Scot; Villanueva, Linda; Hollander, David A

    2016-01-01

    Objective The aim of this study was to evaluate the effects of cyclosporine ophthalmic emulsion 0.05% on ocular surface staining and visual performance in patients with dry eye. Methods This was a single-center, 6-month, open-label, Phase IV study. Patients with bilateral dry eye disease and a symptom score of ≥2 on the Ocular Discomfort and 4-Symptom Questionnaire, an Ocular Surface Disease Index score of >12, at least one eye with Schirmer’s score <10 mm/5 minutes, and central corneal staining graded as ≥2 on the Ora Calibra™ Corneal and Conjunctival Staining Scale were enrolled. Cyclosporine ophthalmic emulsion 0.05% (Restasis®) was instilled twice daily in each eye. The primary efficacy endpoints were ocular surface staining and visual function at 6 months. Secondary outcome measures included Schirmer’s test, tear film breakup time, symptoms, and adverse events. Results A total of 40 patients with the mean age of 59.4 years (range, 40–78 years) were enrolled; 35 (87.5%) were female and 37 (92.5%) completed the study. At 6 months, inferior corneal, central corneal, total corneal, and total ocular surface fluorescein staining were significantly improved from baseline in both eyes (P<0.001). Patient responses on the Ocular Surface Disease Index showed significant improvement in blurred vision and visual function related to reading, driving at night, working with a computer or bank machine, and watching television (P≤0.041). At 6 months, 35.1% of patients achieved ≥5 mm improvement and 18.9% achieved ≥10 mm improvement in the average eye Schirmer score. Mean tear film breakup time improved by >50% in both eyes (P>0.001). Patients reported significant improvement in ocular discomfort and dry eye symptoms (P<0.001). No patients discontinued treatment because of stinging or any other ocular adverse event. Conclusion Dry eye patients with difficulties with day-to-day visual function demonstrated improvement in both signs and symptoms of dry eye and

  20. Reduction of quaternary ammonium-induced ocular surface toxicity by emulsions: an in vivo study in rabbits

    PubMed Central

    Liang, H.; Brignole-Baudouin, F.; Rabinovich-Guilatt, L.; Mao, Z.; Riancho, L.; Faure, M.O.; Warnet, J.M.; Lambert, G.

    2008-01-01

    Purpose To evaluate and compare the toxicological profiles of two quaternary ammonium compounds (QAC), benzalkonium chloride (BAK), and cetalkonium chloride (CKC), in standard solution or cationic emulsion formulations in rabbit eyes using newly developed in vivo and ex vivo experimental approaches. Methods Seventy eyes of 35 adult male New Zealand albino rabbits were used in this study. They were randomly divided into five groups: 50 µl of phosphate-buffered saline (PBS), PBS containing 0.02% BAK or 0.002% CKC (BAK Sol and CKC Sol, respectively), and emulsion containing 0.02% BAK or 0.002% CKC (BAK Em and CKC Em, respectively) were applied to rabbit eyes 15 times at 5-min intervals. The ocular surface changes induced by these eye drops were investigated using slit-lamp examination, flow cytometry (FCM), impression cytology (IC) on conjunctiva, and corneal in vivo confocal microscopy (IVCM). Standard immunohistology in cryosections was also examined for cluster of differentiation (CD) 45+ infiltrating and terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL)+ apoptotic cells. Results Clinical observations and IVCM showed that the highest toxicity was induced by BAK Sol, characterized by damaged corneal epithelium and a high level of inflammatory infiltration. BAK Em and CKC Sol presented moderate effects, and CKC Em showed the lowest toxicity with results similar to those of PBS. Conjunctival imprints analyzed by FCM showed a higher expression of RLA-DR and TNFR1 markers in BAK Sol-instilled eyes than in all other groups, especially at 4 h. Immunohistology was correlated with in vivo and ex vivo findings and confirmed this toxicity profile. A high level of infiltration of CD45+ inflammatory cells and TUNEL+ apoptotic cells was observed in limbus and conjunctiva, especially in QAC solution-receiving eyes compared to QAC emulsion-instilled eyes. Conclusions The acute administration of 15 instillations at 5 min intervals was a rapid and

  1. Surface moisture estimation in urban areas

    NASA Astrophysics Data System (ADS)

    Jiang, Yitong

    Surface moisture is an important parameter because it modifies urban microclimate and surface layer meteorology. The primary objectives of this paper are: 1) to analyze the impact of surface roughness from buildings on surface moisture in urban areas; and 2) to quantify the impact of surface roughness resulting from urban trees on surface moisture. To achieve the objectives, two hypotheses were tested: 1) the distribution of surface moisture is associated with the structural complexity of buildings in urban areas; and 2) The distribution and change of surface moisture is associated with the distribution and vigor of urban trees. The study area is Indianapolis, Indiana, USA. In the part of the morphology of urban trees, Warren Township was selected due to the limitation of tree inventory data. To test the hypotheses, the research design was made to extract the aerodynamic parameters, such as frontal areas, roughness length and displacement height of buildings and trees from Terrestrial and Airborne LiDAR data, then to input the aerodynamic parameters into the urban surface energy balance model. The methodology was developed for comparing the impact of aerodynamic parameters from LiDAR data with the parameters that were derived empirically from land use and land cover data. The analytical procedures are discussed below: 1) to capture the spatial and temporal variation of surface moisture, daily and hourly Land Surface Temperature (LST) were downscaled from 4 km to 1 km, and 960 m to 30 m, respectively, by regression between LST and various components that impact LST; 2) to estimate surface moisture, namely soil moisture and evapotranspiration (ET), land surfaces were classified into soil, vegetation, and impervious surfaces, using Linear Spectral Mixture Analysis (LSMA); 3) aerodynamic parameters of buildings and trees were extracted from Airborne and Terrestrial LiDAR data; 4) the Temperature-Vegetation-Index (TVX) method, and the Two-Source-Energy-Balance (TSEB

  2. In Vivo and Impression Cytology Study on the Effect of Compatible Solutes Eye Drops on the Ocular Surface Epithelial Cell Quality in Dry Eye Patients

    PubMed Central

    Lanzini, Manuela; Curcio, Claudia; Colabelli-Gisoldi, Rossella Annamaria; Mastropasqua, Alessandra; Calienno, Roberta; Agnifili, Luca; Nubile, Mario; Mastropasqua, Leonardo

    2015-01-01

    The aim of this study is to investigate in vivo and ex vivo ocular surface alterations induced by dry eye disease and modification after osmoprotective therapy. Forty-eight eyes of 24 patients suffering from dry eye have been recruited. All patients received Optive (compatible solutes) eye drops in one randomly selected eye and Hylogel (sodium hyaluronate 0,2%) in the other. Follow-up included a baseline visit and further examination 30-, 60-, and 90-day intervals (which comprises clinical evaluation, in vivo confocal microscopy—IVCM—of the ocular surface, and conjunctival impression cytology). No significant difference in Schirmer I Test, TBUT, and vital staining results was observed during the follow-up period in both groups. IVCM showed in all patients an improvement of ocular surface epithelial morphology and signs of inflammation (oedema and keratocyte activation). However, these modifications were more evident in patients treated with Optive therapy. A significant reduction of the expression of MMP9 and IL6 in Optive group was observed during the follow-up period in comparison to Hylogel treatment. Our results show that in dry eye disease therapy based on osmoprotective eye drops determines a reduction of inflammatory activation of ocular surface, with consequent improvement of the quality of corneal and conjunctival epithelium. PMID:26221061

  3. Ocular injuries in automobile crashes.

    PubMed

    Huelke, D F; O'Day, J; Barhydt, W H

    1982-01-01

    Tempered windshields commonly used in Europe have been shown to be related to the relatively high incidence of ocular injuries. Although windshields of the High Penetration Resistant (HPR) type in cars in North America are not at all significantly involved in ocular injuries, still about 50 % of the injuries of the eye area are caused by glass. The HPR windshield probably is the main reason for the relatively low occurrence of ocular injuries in United States crashes compared to these injuries reported from countries with tempered windshields. No ocular injuries were observed among belted occupants in this study. It appears that the increased use of lap-shoulder belts would decrease the likelihood of occupant contact with the windshield, mirrors, roof support, steering wheel, and instrument panel- about two thirds of the occupant contacts related to ocular injury- and thus reduce the incidence of ocular injuries leading to decreased vision.

  4. Ocular Sarcoidosis

    PubMed Central

    Pasadhika, Sirichai; Rosenbaum, James T

    2015-01-01

    Sarcoidosis is one of the leading causes of inflammatory eye disease. Ocular sarcoidosis can involve any part of the eye and its adnexal tissues, and may cause uveitis, episcleritis/scleritis, eyelid abnormalities, conjunctival granuloma, optic neuropathy, lacrimal gland enlargement and orbital inflammation. Glaucoma and cataract can be complications from inflammation itself or adverse effects from therapy. Ophthalmic manifestations can be isolated, or associated with other organ involvement. Patients with ocular sarcoidosis can present with a wide range of clinical presentations and severity. Multi-disciplinary approaches are required to achieve the best treatment outcomes for both ocular and systemic manifestations. PMID:26593141

  5. [Steroid induced ocular hypertension and glaucoma].

    PubMed

    Călugăru, D; Călugăru, M

    2009-01-01

    Steroid induced ocular hypertension and glaucoma represent iatrogenic changes of pharmacogenic nature. They are mainly due to exogenous steroids following ocular periocular, intravitreal and systemic administration. Elevated ocular pressure is brought about by structural trabecular changes as well as obstruction of the outflow ways of the aqueous humor localized within the trabecular juxtacanalicular area. Although mostly raised ocular pressure spontaneously descends to basal values after ceasing the steroid therapy, progressive optic nerve damages and glaucomatous visual field defects may occur. Therapy of steroid induced ocular hypertension and glaucoma is similar to that of ocular hypertension and primary open-angle glaucoma.

  6. Volumes and surface areas of pendular rings

    USGS Publications Warehouse

    Rose, W.

    1958-01-01

    A packing of spheres is taken as a suitable model of porous media. The packing may be regular and the sphere size may be uniform, but in general, both should be random. Approximations are developed to give the volumes and surface areas of pendular rings that exist at points of sphere contact. From these, the total free volume and interfacial specific surface area are derived as expressive of the textural character of the packing. It was found that the log-log plot of volumes and surface areas of pendular rings vary linearly with the angle made by the line joining the sphere centers and the line from the center of the largest sphere to the closest edge of the pendular ring. The relationship, moreover, was found not to be very sensitive to variation in the size ratio of the spheres in contact. It also was found that the addition of pendular ring material to various sphere packings results in an unexpected decrease in the surface area of the boundaries that confine the resulting pore space. ?? 1958 The American Institute of Physics.

  7. Osmosis and Surface Area to Volume Ratio.

    ERIC Educational Resources Information Center

    Barrett, D. R. B.

    1984-01-01

    Describes an experiment designed to help students understand the concepts of osmosis and surface area to volume ratio (SA:VOL). The task for students is to compare water uptake in different sizes of potato cubes and relate differences to their SA:VOL ratios. (JN)

  8. Human body surface area: a theoretical approach.

    PubMed

    Wang, Jianfeng; Hihara, Eiji

    2004-04-01

    Knowledge of the human body surface area has important applications in medical practice, garment design, and other engineering sizing. Therefore, it is not surprising that several expressions correlating body surface area with direct measurements of body mass and length have been reported in the literature. In the present study, based on the assumption that the exterior shape of the human body is the result of convex and concave deformations from a basic cylinder, we derive a theoretical equation minimizing body surface area (BSA) at a fixed volume (V): BSA=(9pi VL)(0.5), where L is the reference length of the body. Assuming a body density value of 1,000 kg.m(-3), the equation becomes BSA=(BM.BH/35.37)(0.5), where BSA is in square meters, BM is the body mass in kilograms, and BH is the body height in meters. BSA values calculated by means of this equation fall within +/-7% of the values obtained by means of the equations available in the literature, in the range of BSA from children to adults. It is also suggested that the above equation, which is obtained by minimizing the outer body surface at a fixed volume, implies a fundamental relation set by the geometrical constraints governing the growth and the development of the human body.

  9. An efficient automated algorithm to detect ocular surface temperature on sequence of thermograms using snake and target tracing function.

    PubMed

    Tan, Jen Hong; Ng, E Y K; Acharya U, Rajendra

    2011-10-01

    Functional infrared (IR) imaging is widely adopted in medical field nowadays, with more emphasis on breast cancer and ocular abnormalities. In this article, an algorithm is presented to accurately locate the eye and cornea in ocular thermographic sequences, which were recorded utilizing functional infrared imaging. The localization is achieved by snake algorithm coupled with a newly proposed target tracing function. The target tracing function enables automated localization, allows the absence of any manual assistance before the algorithm runs. Genetic algorithm is used to perform the search for global minimum on the function to produce desired localization. On all the cases we have studied, in average the region encircled by the algorithm covers 92% of the true ocular region. As for the non-ocular region covered, it only accounts for less than 5% of the encircled region.

  10. Ocular involvement of brucellosis.

    PubMed

    Bazzazi, Nooshin; Yavarikia, Alireza; Keramat, Fariba

    2013-01-01

    A 29-year-old male diagnosed with brucellosis a week earlier was referred to the ophthalmology clinic with visual complaints. On examination, visual acuity was 20/25, he had conjunctival injection on slit lamp examination. There was also bilateral optic disk swelling plus retinal hyperemia (optic disc hyperemia and vascular tortuosity) and intraretinal hemorrhage on funduscopy. The patient was admitted and treated with cotrimoxazole, rifampin, doxycycline and prednisolone for 2 months. Ocular manifestations subsided gradually within 6 months after treatment. Brucellosis can affect the eye and lead to serious ocular complications. Early diagnosis and prompt treatment should be considered in endemic areas.

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

    PubMed

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

    2010-06-01

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

  12. Clinical Usefulness of Monitoring Expression Levels of CCL24 (Eotaxin-2) mRNA on the Ocular Surface in Patients with Vernal Keratoconjunctivitis and Atopic Keratoconjunctivitis

    PubMed Central

    2016-01-01

    Purpose. This study aimed to evaluate the clinical efficacy of using expression levels of CCL24 (eotaxin-2) mRNA on the ocular surface as a biomarker in patients with vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC). Methods. Eighteen patients with VKC or AKC (VKC/AKC group) and 12 control subjects (control group) were enrolled in this study. The VKC/AKC clinical score was determined by objective findings in patients by using the 5-5-5 exacerbation grading scale. All subjects underwent modified impression cytology and specimens were obtained from the upper tarsal conjunctiva. Expression levels of CCL24 (eotaxin-2) mRNA on the ocular surface were determined using real-time reverse transcription polymerase chain reaction. Results. The VKC group was divided into two subgroups, depending on the clinical score: the active stage subgroup with 100 points or more of clinical scores and the stable stage subgroup with 100 points or less. CCL24 (eotaxin-2) mRNA expression levels in the active VKC/AKC stage subgroup were significantly higher than those in the stable VKC/AKC subgroup and the control group. Clinical scores correlated significantly with CCL24 (eotaxin-2) mRNA expression levels in the VKC group. Conclusions. CCL24 (eotaxin-2) mRNA expression levels on the ocular surface are a useful biomarker for clinical severity of VKC/AKC. PMID:27721987

  13. α-Melanocyte-stimulating hormone ameliorates ocular surface dysfunctions and lesions in a scopolamine-induced dry eye model via PKA-CREB and MEK-Erk pathways.

    PubMed

    Ru, Yusha; Huang, Yue; Liu, Huijuan; Du, Juan; Meng, Zhu; Dou, Zexia; Liu, Xun; Wei, Rui Hua; Zhang, Yan; Zhao, Shaozhen

    2015-12-21

    Dry eye is a highly prevalent, chronic, and multifactorial disease that compromises quality of life and generates socioeconomic burdens. The pathogenic factors of dry eye disease (DED) include tear secretion abnormalities, tear film instability, and ocular surface inflammation. An effective intervention targeting the pathogenic factors is needed to control this disease. Here we applied α-Melanocyte-stimulating hormone (α-MSH) twice a day to the ocular surface of a scopolamine-induced dry eye rat model. The results showed that α-MSH at different doses ameliorated tear secretion, tear film stability, and corneal integrity, and corrected overexpression of proinflammatory factors, TNF-α, IL-1β, and IFN-γ, in ocular surface of the dry eye rats. Moreover, α-MSH, at 10(-4) μg/μl, maintained corneal morphology, inhibited apoptosis, and restored the number and size of conjunctival goblet cells in the dry eye rats. Mechanistically, α-MSH activated both PKA-CREB and MEK-Erk pathways in the dry eye corneas and conjunctivas; pharmacological blockade of either pathway abolished α-MSH's protective effects, suggesting that both pathways are necessary for α-MSH's protection under dry eye condition. The peliotropic protective functions and explicit signaling mechanism of α-MSH warrant translation of the α-MSH-containing eye drop into a novel and effective intervention to DED.

  14. Comparative proteomics reveals human pluripotent stem cell-derived limbal epithelial stem cells are similar to native ocular surface epithelial cells

    PubMed Central

    Mikhailova, Alexandra; Jylhä, Antti; Rieck, Jochen; Nättinen, Janika; Ilmarinen, Tanja; Veréb, Zoltán; Aapola, Ulla; Beuerman, Roger; Petrovski, Goran; Uusitalo, Hannu; Skottman, Heli

    2015-01-01

    Limbal epithelial stem cells (LESCs) are tissue-specific stem cells responsible for renewing the corneal epithelium. Acute trauma or chronic disease affecting LESCs may disrupt corneal epithelial renewal, causing vision threatening and painful ocular surface disorders, collectively referred to as LESC deficiency (LESCD). These disorders cannot be treated with traditional corneal transplantation and therefore alternative cell sources for successful cell-based therapy are needed. LESCs derived from human pluripotent stem cells (hPSCs) are a prospective source for ocular surface reconstruction, yet critical evaluation of these cells is crucial before considering clinical applications. In order to quantitatively evaluate hPSC-derived LESCs, we compared protein expression in native human corneal cells to that in hPSC-derived LESCs using isobaric tag for relative and absolute quantitation (iTRAQ) technology. We identified 860 unique proteins present in all samples, including proteins involved in cell cycling, proliferation, differentiation and apoptosis, various LESC niche components, and limbal and corneal epithelial markers. Protein expression profiles were nearly identical in LESCs derived from two different hPSC lines, indicating that the differentiation protocol is reproducible, yielding homogeneous cell populations. Their protein expression profile suggests that hPSC-derived LESCs are similar to the human ocular surface epithelial cells, and possess LESC-like characteristics. PMID:26423138

  15. Ocular Pathology.

    PubMed

    Bauer, Bianca S

    2015-08-01

    Although not comprehensive of all ocular conditions in the equine species, this article concentrates on various ophthalmic conditions observed in the horse where laboratory diagnostics are recommended. The importance of laboratory diagnostic testing cannot be underestimated with equine ophthalmic disease. In many cases, laboratory diagnostics can aid in obtaining an early diagnosis and determining appropriate therapy, which in turn, can provide a better prognosis. In unfortunate cases where ocular disease results in a blind, painful eye necessitating enucleation, light microscopic evaluation is imperative to determine or confirm the cause of the blindness and provide a prognosis for the contralateral eye.

  16. Cultivated Oral Mucosa Epithelium in Ocular Surface Reconstruction in Aniridia Patients

    PubMed Central

    Dobrowolski, Dariusz; Orzechowska-Wylegala, Boguslawa; Wowra, Bogumil; Wroblewska-Czajka, Ewa; Grolik, Maria; Szczubialka, Krzysztof; Nowakowska, Maria; Puzzolo, Domenico; Wylegala, Edward A.; Micali, Antonio; Aragona, Pasquale

    2015-01-01

    Purpose. Efficacy of cultivated oral mucosa epithelial transplantation (COMET) procedure in corneal epithelium restoration of aniridia patients. Methods. Study subjects were aniridia patients (13 patients; 17 eyes) with irregular, vascular conjunctival pannus involving visual axis who underwent autologous transplantation of cultivated epithelium. For the procedure oral mucosa epithelial cells were obtained from buccal mucosa with further enzymatic treatment. Suspension of single cells was seeded on previously prepared denuded amniotic membrane. Cultures were carried on culture dishes inserts in the presence of the inactivated with Mitomycin C monolayer of 3T3 fibroblasts. Cultures were carried for seven days. Stratified oral mucosa epithelium with its amniotic membrane carrier was transplanted on the surgically denuded corneal surface of aniridia patients with total or subtotal limbal stem cell deficiency. Outcome Measures. Corneal surface, epithelial regularity, and visual acuity improvement were evaluated. Results. At the end of the observation period, 76.4% of the eyes had regular transparent epithelium and 23.5% had developed epithelial defects or central corneal haze; in 88.2% of cases visual acuity had increased. VA range was from HM 0.05 before the surgery to HM up to 0.1 after surgery. Conclusion. Application of cultivated oral mucosa epithelium restores regular epithelium on the corneal surface with moderate improvement in quality of vision. PMID:26451366

  17. Ocular phototherapy.

    PubMed

    Singh, A D

    2013-02-01

    Phototherapy can be translated to mean 'light or radiant energy-induced treatment.' Lasers have become the exclusive source of light or radiant energy for all applications of phototherapy. Depending on the wavelength, intensity, and duration of exposure, tissues can either absorb the energy (photocoagulation, thermotherapy, and photodynamic therapy (PDT)) or undergo ionization (photodisruption). For phototherapy to be effective, the energy has to be absorbed by tissues or more specifically by naturally occurring pigment (xanthophyll, haemoglobin, and melanin) within them. In tissues or tumours that lack natural pigment, dyes (verteporphin, Visudyne) with narrow absorption spectrum can be injected intravenously that act as focal absorbent of laser energy after they have preferentially localized within the tumour. Ocular phototherapy has broad applications in treatment of ocular tumours. Laser photocoagulation, thermotherapy, and PDT can be delivered with low rates of complications and with ease in the outpatient setting. Review of the current literature suggests excellent results when these treatments are applied for benign tumours, particularly for vascular tumours such as circumscribed choroidal haemangioma. For primary malignant tumours, such as choroidal melanoma, thermotherapy, and PDT do not offer local tumour control rates that are equivalent or higher than those achieved with plaque or proton radiation therapy. However, for secondary malignant tumours (choroidal metastases), thermotherapy and PDT can be applied as a palliative treatment. Greater experience is necessary to fully comprehend risks, comparative benefits, and complication of ocular phototherapy of ocular tumours.

  18. Corneal sensitivity, ocular surface health and tear film stability after punctal plug therapy of aqueous deficient dry eye

    PubMed Central

    Said, Azza Mohamed Ahmed; Farag, Mona Elsayed; Abdulla, Tarek Mohamed; Ziko, Othman Ali Othman; Osman, Wesam Mohamed

    2016-01-01

    AIM To evaluate the effect of punctal occlusion using thermosensitive (smart plug) versus silicone plug for management of aqueous deficient dry eye on corneal sensitivity, ocular surface health and tear film stability. METHODS A comparative prospective interventional case study included 45 patients with bilateral severe form of aqueous deficient dry eye. In each patient, the smart plug was inserted in the lower punctum of the right eye which was considered as study group 1 and silicone plug was inserted in the lower punctum of the left eye of the same patient which was considered as study group 2. All patients were subjected to careful history taking and questionnaire for subjective assessment of severity of symptoms. Corneal sensitivity, corneal fluorescein, rose bengal staining, Schirmer's I test, tear film break up time and conjunctival impression cytology were performed pre and 1, 3 and 6mo post plug insertion. RESULTS A statistically significant improvement in subjective and objective manifestations occurred following treatment with both types of plugs (P<0.01). The thermosensitive plug caused significant overall improvement, decrease in frequency of application of tear substitutes and improvement of conjunctival impression cytology parameters in the inserted side (P<0.01). Canaliculitis was reported in two eyes (4.4%) following punctal occlusion using thermosensitive plug (study group 1). Spontaneous plug loss occurred in 21 eyes (46.6%) in the silicone plug group (study group 2). CONCLUSION Improvement of subjective and objective manifestations of aqueous deficient dry eye occurs following punctal plug occlusion. Thermosensitive plug has good patient's compliance with fewer complications and lower rates of loss compared to the silicone plug. PMID:27990362

  19. Characterization of surface runoff in urban areas.

    PubMed

    Choe, J S; Bang, K W; Lee, J H

    2002-01-01

    Water quality measurements of surface runoff have been carried out in selected residential and industrial zones in urban areas, in which yearly mean precipitation is 1,225 mm. The concentrations of constituents in the surface runoff were measured at sampling sites categorized by land use type in the residential zone, and by industry type in the industrial zone. The water quality constituents of BOD5, COD, SS, NO3-N, TKN, PO4-P, TP, n-Hexane extracts, Cr, Cu, Pb and Fe were analyzed. The event mean concentrations (EMCs) of COD, SS, TKN and TP in the residential zone were 313 mg/L, 279 mg/L, 8.45 mg/L, 1.98 mg/L, and those in the industrial zone were 80 mg/L, 106 mg/L, 5.07 mg/L, and 1.93 mg/L, respectively. Cumulative load curves were created to analyze the first-flushing effect of each pollutant related to the pollutant, the rainfall event, and the land use type. No general relationship between the cumulative load and runoff has been established. The degree of first-flushing effect by constituents was in the following order; TKN>COD>SS>HEM>TP>PO4-P. The correlations between SS and other constituents were analyzed to evaluate the efficiency of the physical treatment process to control the surface runoff in urban areas. Based on the correlation of constituents with SS, high treatment efficiency of SS, heavy metals, organic matter, and TP was expected. The unit pollutant loading rates of COD, SS, TKN, TP, Cr and Pb in the residential zone were 2,392, 2,130, 64.6, 15.1, 0.31, and 1.83 kg/ha/yr, and those in the industrial zone were 612, 812, 38.7, 14.8, 0.51 and 0.82 kg/ha/yr, respectively.

  20. Ocular complications of diabetes mellitus

    PubMed Central

    Sayin, Nihat; Kara, Necip; Pekel, Gökhan

    2015-01-01

    Diabetes mellitus (DM) is a important health problem that induces ernestful complications and it causes significant morbidity owing to specific microvascular complications such as, retinopathy, nephropathy and neuropathy, and macrovascular complications such as, ischaemic heart disease, and peripheral vasculopathy. It can affect children, young people and adults and is becoming more common. Ocular complications associated with DM are progressive and rapidly becoming the world’s most significant cause of morbidity and are preventable with early detection and timely treatment. This review provides an overview of five main ocular complications associated with DM, diabetic retinopathy and papillopathy, cataract, glaucoma, and ocular surface diseases. PMID:25685281

  1. Implantation of refractive multifocal intraocular lens with a surface-embedded near section for cataract eyes complicated with a coexisting ocular pathology

    PubMed Central

    Ouchi, M; Kinoshita, S

    2015-01-01

    Purpose To evaluate the postoperative outcomes of cataract eyes complicated with coexisting ocular pathologies that underwent implantation of a refractive multifocal intraocular lens (MIOL) with a surface-embedded near section. Methods LENTIS MPlus (Oculentis GmbH) refractive MIOLs were implanted in 15 eyes with ocular pathologies other than cataract (ie, six high-myopia eyes with an axial length longer than 28 mm, two fundus albipunctatus eyes, two branch retinal-vein occlusion eyes, four glaucoma eyes (one with high myopia), and two keratoconus eyes). Uncorrected or corrected distance and near visual acuity (VA) (UDVA, UNVA, CDVA, and CNVA), contrast sensitivity, and defocus curve were measured at 1 day and 6 months postoperatively, and each patient completed a 6-month postoperative questionnaire regarding vision quality and eyeglass use. Results Thirteen eyes (87%) registered 0 or better in CDVA and 12 eyes (73%) registered better than 0 in CNVA. Contrast sensitivity in the eyes of all patients was comparable to that of normal healthy subjects. No patient required eyeglasses for distance vision, but three patients (20%) required them for near vision. No patient reported poor or very poor vision quality. Conclusion With careful case selection, sectorial refractive MIOL implantation is effective for treating cataract eyes complicated with ocular pathologies. PMID:25744442

  2. Ocular metastases

    PubMed Central

    Cohen, V M L

    2013-01-01

    The eye is a rare site for disseminated malignancy because of the absence of a lymphatic system. Metastases to the ocular structures occur by haematogenous spread and therefore the parts of the eye with the best vascular supply are most likely to be affected. Many patients with Stage 4 carcinomatosis (distal metastatic spread) already have a history of a previous primary cancer. However, this is not always the case for lung cancer as this can metastasise early to the uveal tract and therefore the ophthalmologist may be the first to discover the presence of terminal metastatic disease. Broadly speaking, treatment options are focused on improving the patients' quality of life if visual acuity is threatened. Long-term side effects of treatment need to be considered as systemic cancer treatments and therefore patient life expectancy is improving. In this manuscript, presented at the Cambridge symposium 2012, the diagnosis and challenges involved in the management of ocular metastases are presented. PMID:23222564

  3. Damage areas on selected LDEF aluminum surfaces

    NASA Technical Reports Server (NTRS)

    Coombs, Cassandra R.; Atkinson, Dale R.; Allbrooks, Martha K.; Watts, Alan J.; Hennessy, Corey J.; Wagner, John D.

    1993-01-01

    With the U.S. about to embark on a new space age, the effects of the space environment on a spacecraft during its mission lifetime become more relevant. Included among these potential effects are degradation and erosion due to micrometeoroid and debris impacts, atomic oxygen and ultraviolet light exposure as well as material alteration from thermal cycling, and electron and proton exposure. This paper focuses on the effects caused by micrometeoroid and debris impacts on several LDEF aluminum plates from four different bay locations: C-12, C-10, C-01, and E-09. Each plate was coated with either a white, black, or gray thermal paint. Since the plates were located at different orientations on the satellite, their responses to the hypervelocity impacts varied. Crater morphologies range from a series of craters, spall zones, domes, spaces, and rings to simple craters with little or no spall zones. In addition, each of these crater morphologies is associated with varying damage areas, which appear to be related to their respective bay locations and thus exposure angles. More than 5% of the exposed surface area examined was damaged by impact cratering and its coincident effects (i.e., spallation, delamination and blow-off). Thus, results from this analysis may be significant for mission and spacecraft planners and designers.

  4. Current concepts of ocular adnexal surgery

    PubMed Central

    Borrelli, Maria; Geerling, Gerd

    2013-01-01

    Ophthalmic Plastic and Reconstructive Surgery is a specialized area of ophthalmology that deals with the management of deformities and abnormalities of the eyelids, lacrimal system and the orbit. An ophthalmoplastic surgeon is able to identify and correct abnormalities of the ocular adnexae such as ectropion, lid retraction, conjunctival scarring with severe entropion, that can cause secondary ocular surface disorders; manage patients with watering eye, and when needed intervene with a dacryocystorhinostomy by external or endonasal approach and moreover minimize disfigurement following enucleation or evisceration and prevent further corneal damage, alleviate complains of tearing and grittiness, but also cosmetic complaints in patients with Graves’ orbitopathy. Aim of this manuscript was to review current established and recently evolving surgical procedures. PMID:26504698

  5. ­­Presence and distribution of 14-3-3 proteins in human ocular surface tissues

    PubMed Central

    Shankardas, Jwalitha; Senchyna, Michelle

    2008-01-01

    Purpose 14–3-3 is a highly conserved, ubiquitously expressed family of proteins. At least seven mammalian isoforms (β, ε, γ, η, θ, σ, and ζ) are known. These proteins associate with over 200 different target molecules and activate several downstream signaling cascades involved in the regulation of metabolism, cell cycle, apoptosis, protein trafficking, transcription, stress responses, and malignant transformations. We are interested in the role of these proteins in the mechanisms regulating homeostasis and the pathologies of the human ocular surface. Therefore, our purpose is to determine the expression of the 14–3-3 proteins in the human cornea, the conjunctiva, and the primary cells comprising these tissues. Methods Using immunofluorescence, we determined the expression of 14–3-3 β, ε, γ, η, θ, σ, and ζ in paraffin sections of the human cornea and conjunctiva. Using indirect immunofluorescence and western blot analysis, we also determined the expression of these isoforms in primary corneal epithelial cells, keratocytes, endothelial cells, and primary conjunctival epithelial cells. The expressions of these isoforms in primary epithelial and endothelial cells were compared with the same expressions in several corneal cell lines. Western blot analysis was used to determine the presence of 14–3-3 isoforms in the culture medium from corneal epithelial cells, cell lines, and the tear fluid. Results All the 14–3-3 isoforms were expressed in the corneal and conjunctival epithelia as well as primary epithelial cells and cell lines. Expression of 14–3-3 σ was confined to epithelial cells and was secreted into the culture medium of primary cells and cell lines. We also report for the first time that two of the secreted isoforms, 14–3-3 γ and ζ, are also present in the human tear fluid. Conclusions We have determined that all the mammalian 14–3-3 isoforms are expressed in the human cornea, conjunctiva, and the component cells and that the 14

  6. [Ocular biometry using Orbscan].

    PubMed

    Touzeau, O; Allouch, C; Borderie, V; Laroche, L

    2005-06-01

    Orbscan is a recent optical device that combines the Placido disk of the videokeratoscope and a scanning slit. The scanning slit measures the elevation of both the corneal surface (anterior and posterior) and the anterior iris-lens surface. Biometric measures of the anterior segment such as corneal thickness, anterior chamber depth, corneal diameter, and iridocorneal angle are obtained using spatial coordinates of various ocular surfaces. Orbscan is not only a corneal topograph but a versatile device capable of measuring the biometry of the anterior segment of the eye.

  7. Body surface area formulae: an alarming ambiguity

    PubMed Central

    Redlarski, Grzegorz; Palkowski, Aleksander; Krawczuk, Marek

    2016-01-01

    Body surface area (BSA) plays a key role in several medical fields, including cancer chemotherapy, transplantology, burn treatment and toxicology. BSA is often a major factor in the determination of the course of treatment and drug dosage. A series of formulae to simplify the process have been developed. Because easy-to-identify, yet general, body coefficient results of those formulae vary considerably, the question arises as to whether the choice of a particular formula is valid and safe for patients. Here we show that discrepancies between most of the known BSA formulae can reach 0.5 m2 for the standard adult physique. Although many previous studies have demonstrated that certain BSA formulae provide an almost exact fit with the patients examined, all of these studies have been performed on a limited and isolated group of people. Our analysis presents a broader perspective, considering 25 BSA formulae. The analysis revealed that the choice of a particular formula is a difficult task. Differences among calculations made by the formulae are so great that, in certain cases, they may considerably affect patients’ mortality, especially for people with an abnormal physique or for children. PMID:27323883

  8. Body surface area formulae: an alarming ambiguity.

    PubMed

    Redlarski, Grzegorz; Palkowski, Aleksander; Krawczuk, Marek

    2016-06-21

    Body surface area (BSA) plays a key role in several medical fields, including cancer chemotherapy, transplantology, burn treatment and toxicology. BSA is often a major factor in the determination of the course of treatment and drug dosage. A series of formulae to simplify the process have been developed. Because easy-to-identify, yet general, body coefficient results of those formulae vary considerably, the question arises as to whether the choice of a particular formula is valid and safe for patients. Here we show that discrepancies between most of the known BSA formulae can reach 0.5 m(2) for the standard adult physique. Although many previous studies have demonstrated that certain BSA formulae provide an almost exact fit with the patients examined, all of these studies have been performed on a limited and isolated group of people. Our analysis presents a broader perspective, considering 25 BSA formulae. The analysis revealed that the choice of a particular formula is a difficult task. Differences among calculations made by the formulae are so great that, in certain cases, they may considerably affect patients' mortality, especially for people with an abnormal physique or for children.

  9. Clinical and Immunological Responses in Ocular Demodecosis

    PubMed Central

    Kim, Jae Hoon; Chun, Yeoun Sook

    2011-01-01

    The purpose of this study was to investigate clinical and immunological responses to Demodex on the ocular surface. Thirteen eyes in 10 patients with Demodex blepharitis and chronic ocular surface disorders were included in this study and treated by lid scrubbing with tea tree oil for the eradication of Demodex. We evaluated ocular surface manifestations and Demodex counts, and analyzed IL-1β, IL-5, IL-7, IL-12, IL-13, IL-17, granulocyte colony-stimulating factor, and macrophage inflammatory protein-1β in tear samples before and after the treatment. All patients exhibited ocular surface manifestations including corneal nodular opacity, peripheral corneal vascularization, refractory corneal erosion and infiltration, or chronic conjunctival inflammatory signs before treatment. After treatment, Demodex was nearly eradicated, tear concentrations of IL-1β and IL-17 were significantly reduced and substantial clinical improvement was observed in all patients. In conclusion, we believe that Demodex plays an aggravating role in inflammatory ocular surface disorders. PMID:21935281

  10. Clinical and immunological responses in ocular demodecosis.

    PubMed

    Kim, Jae Hoon; Chun, Yeoun Sook; Kim, Jae Chan

    2011-09-01

    The purpose of this study was to investigate clinical and immunological responses to Demodex on the ocular surface. Thirteen eyes in 10 patients with Demodex blepharitis and chronic ocular surface disorders were included in this study and treated by lid scrubbing with tea tree oil for the eradication of Demodex. We evaluated ocular surface manifestations and Demodex counts, and analyzed IL-1β, IL-5, IL-7, IL-12, IL-13, IL-17, granulocyte colony-stimulating factor, and macrophage inflammatory protein-1β in tear samples before and after the treatment. All patients exhibited ocular surface manifestations including corneal nodular opacity, peripheral corneal vascularization, refractory corneal erosion and infiltration, or chronic conjunctival inflammatory signs before treatment. After treatment, Demodex was nearly eradicated, tear concentrations of IL-1β and IL-17 were significantly reduced and substantial clinical improvement was observed in all patients. In conclusion, we believe that Demodex plays an aggravating role in inflammatory ocular surface disorders.

  11. Detection of Acanthamoeba on the ocular surface in a Spanish population using the Schirmer strip test: pathogenic potential, molecular classification and evaluation of the sensitivity to chlorhexidine and voriconazole of the isolated Acanthamoeba strains.

    PubMed

    Rocha-Cabrera, Pedro; Reyes-Batlle, María; Martín-Navarro, Carmen María; Dorta-Gorrín, Alexis; López-Arencibia, Atteneri; Sifaoui, Ines; Martínez-Carretero, Enrique; Piñero, José E; Martín-Barrera, Fernando; Valladares, Basilio; Lorenzo-Morales, Jacob

    2015-08-01

    Pathogenic strains of Acanthamoeba are causative agents of a sight-threatening infection of the cornea known as Acanthamoeba keratitis, which is often associated with the misuse of contact lenses. However, there is still a question remaining to be answered, which is whether these micro-organisms are present on the ocular surface of healthy individuals. Therefore, the aim of this study was to determine the presence of Acanthamoeba on the ocular surface in healthy patients and also in those with other ocular surface infections. Sterile Schirmer test strips were used to collect samples from a group of patients who attended an ophthalmology consultation at the Hospital del Norte, Icod de los Vinos, Tenerife, Canary Islands. Most of the patients (46 individuals, 79.31  %) presented ocular surface pathologies such as blepharitis or conjunctivitis; the rest did not present any pathology. None of the patients included in the study wore contact lenses. The collected samples were cultured in 2  % non-nutrient agar plates and positive plates were then cultured in axenic conditions for further analyses. Molecular analysis classified all isolated strains as belonging to Acanthamoeba genotype tbl4, and osmotolerance and thermotolerance assays revealed that all strains were potentially pathogenic. Furthermore, all strains were assayed for sensitivity against voriconazole and chlorhexidine. Assays showed that both drugs were active against the tested strains. In conclusion, the Schirmer strip test is proposed as an effective tool for the detection of Acanthamoeba on the ocular surface.

  12. A Comparison of the Effects of Benzalkonium Chloride on Ocular Surfaces between C57BL/6 and BALB/c Mice.

    PubMed

    Yang, Qian; Zhang, Yafang; Liu, Xiuping; Wang, Nan; Song, Zhenyu; Wu, Kaili

    2017-02-26

    Models of benzalkonium chloride (BAC)-induced ocular disruption have been created and are widely used in various animals. This study aimed to compare the effects of BAC on the ocular surfaces of C57BL/6 and BALB/c mice. C57BL/6 and BALB/c mice were treated separately with BAC eye-drops at different concentrations. Eyes were evaluated by scoring epithelial disruption, corneal opacity and neovascularization in vivo, and by histological assays with hematoxylin/eosin (H/E) and periodic acid-Schiff stainings and by determining the expression of inflammatory factors in vitro on Days 7 and 14. The in vivo corneal epithelial disruption, corneal edema/opacity and neovascularization, which were in accordance with the results of the H/E staining and peaked at Day 7, were observed in a dose-dependent manner in the BAC-treated mice, with more severe signs in the C57BL/6 mice than the BALB/c mice. The loss of conjunctival goblet cells in the conjunctivas and the increasing expression of monocyte chemoattractant protein 1 (MCP-1), growth-regulated protein alpha (GROa) and macrophage inflammatory protein-1 alpha (MIP-1a) in the corneas were found in a dose-dependent manner in both strains of mice. Topical application of BAC can dramatically disrupt the ocular surfaces of C57BL/6 and BALB/c mice, and the disruptions were much more severe in the C57BL/6 mice that received high doses of BAC.

  13. A Comparison of the Effects of Benzalkonium Chloride on Ocular Surfaces between C57BL/6 and BALB/c Mice

    PubMed Central

    Yang, Qian; Zhang, Yafang; Liu, Xiuping; Wang, Nan; Song, Zhenyu; Wu, Kaili

    2017-01-01

    Models of benzalkonium chloride (BAC)-induced ocular disruption have been created and are widely used in various animals. This study aimed to compare the effects of BAC on the ocular surfaces of C57BL/6 and BALB/c mice. C57BL/6 and BALB/c mice were treated separately with BAC eye-drops at different concentrations. Eyes were evaluated by scoring epithelial disruption, corneal opacity and neovascularization in vivo, and by histological assays with hematoxylin/eosin (H/E) and periodic acid-Schiff stainings and by determining the expression of inflammatory factors in vitro on Days 7 and 14. The in vivo corneal epithelial disruption, corneal edema/opacity and neovascularization, which were in accordance with the results of the H/E staining and peaked at Day 7, were observed in a dose-dependent manner in the BAC-treated mice, with more severe signs in the C57BL/6 mice than the BALB/c mice. The loss of conjunctival goblet cells in the conjunctivas and the increasing expression of monocyte chemoattractant protein 1 (MCP-1), growth-regulated protein alpha (GROa) and macrophage inflammatory protein-1 alpha (MIP-1a) in the corneas were found in a dose-dependent manner in both strains of mice. Topical application of BAC can dramatically disrupt the ocular surfaces of C57BL/6 and BALB/c mice, and the disruptions were much more severe in the C57BL/6 mice that received high doses of BAC. PMID:28245636

  14. Meibography and meibomian gland measurements in ocular graft-versus-host disease.

    PubMed

    Engel, L A; Wittig, S; Bock, F; Sauerbier, L; Scheid, C; Holtick, U; Chemnitz, J-M; Hallek, M; Cursiefen, C; Steven, P

    2015-07-01

    Meibomian gland loss in ocular GvHD was described as a mechanism contributing to dry eye and severe damage to the ocular surface. Infrared images of upper eyelid meibomian glands from 86 ocular GvHD patients, from 10 patients after allogeneic stem cell transplantation (aSCT) without ocular GvHD, from 32 patients prior to aSCT and from 30 healthy controls were analyzed retrospectively and evaluated using two grading schemes. The upper meibomian gland area (uMGA) was calculated and set in relation to the total tarsal area of the lid. Results demonstrate that meibomian gland loss is significantly increased in patients with ocular GvHD as well as in patients prior to aSCT in comparison with controls (P between 0.05 and <0.001). Patients after aSCT without ocular GvHD had no significant difference in uMGA in comparison with controls. This study suggests that meibomian gland loss in GvHD patients is likely to be a multifactorial process that also occurs prior to aSCT, possibly due to underlying diseases and/or secondary to chemotherapy or irradiation. In addition, the question has to be addressed whether meibomian gland loss could serve as a predictor for the development of ocular GvHD. Overall, infrared meibography should be included in routine examination of patients undergoing aSCT and during follow-up.

  15. Ocular dispersion

    NASA Astrophysics Data System (ADS)

    Hammer, Daniel X.; Noojin, Gary D.; Thomas, Robert J.; Stolarski, David J.; Rockwell, Benjamin A.; Welch, Ashley J.

    1999-06-01

    Spectrally resolved white-light interferometry (SRWLI) was used to measure the wavelength dependence of refractive index (i.e., dispersion) for various ocular components. The accuracy of the technique was assessed by measurement of fused silica and water, the refractive indices of which have been measured at several different wavelengths. The dispersion of bovine and rabbit aqueous and vitreous humor was measured from 400 to 1100 nm. Also, the dispersion was measured from 400 to 700 nm for aqueous and vitreous humor extracted from goat and rhesus monkey eyes. For the humors, the dispersion did not deviate significantly from water. In an additional experiment, the dispersion of aqueous and vitreous humor that had aged up to a month was compared to freshly harvested material. No difference was found between the fresh and aged media. An unsuccessful attempt was also made to use the technique for dispersion measurement of bovine cornea and lens. Future refinement may allow measurement of the dispersion of cornea and lens across the entire visible and near-infrared wavelength band. The principles of white- light interferometry including image analysis, measurement accuracy, and limitations of the technique, are discussed. In addition, alternate techniques and previous measurements of ocular dispersion are reviewed.

  16. Ocular leprosy in Hawaii: the past.

    PubMed

    Brown, D H

    1975-08-01

    Leprosy in Hawaii dates back to about 1840. The first recorded ocular leprosy is from the 1880s. Robert Louis Stevenson and Jack London both wrote descriptions of the ocular signs of leprosy. Pinkerton in 1927 and Van Poole in 1934 reported large series of patients with ocular leprosy. In 1973 there were about 2,168 cases of leprosy in the 50 states. Most ophthalmologists practice in areas where there are leprosy patients.

  17. Surface atmospheric extremes (Launch and transportation areas)

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The effects of extreme values of surface and low altitude atmospheric parameters on space vehicle design, tests, and operations are discussed. Atmospheric extremes from the surface to 150 meters for geographic locations of interest to NASA are given. Thermal parameters (temperature and solar radiation), humidity, pressure, and atmospheric electricity (lighting and static) are presented. Weather charts and tables are included.

  18. 30 CFR 56.17001 - Illumination of surface working areas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Illumination of surface working areas. 56.17001... § 56.17001 Illumination of surface working areas. Illumination sufficient to provide safe working conditions shall be provided in and on all surface structures, paths, walkways, stairways, switch...

  19. 30 CFR 57.17001 - Illumination of surface working areas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Illumination of surface working areas. 57.17001... Illumination § 57.17001 Illumination of surface working areas. Illumination sufficient to provide safe working conditions shall be provided in and on all surface structures, paths, walkways, stairways, switch...

  20. 30 CFR 57.17001 - Illumination of surface working areas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Illumination of surface working areas. 57.17001... Illumination § 57.17001 Illumination of surface working areas. Illumination sufficient to provide safe working conditions shall be provided in and on all surface structures, paths, walkways, stairways, switch...

  1. 30 CFR 56.17001 - Illumination of surface working areas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Illumination of surface working areas. 56.17001... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Illumination § 56.17001 Illumination of surface working areas. Illumination sufficient to provide safe...

  2. Surface area and travel time relationships in aquifer treatment systems.

    PubMed

    Fox, Peter; Makam, Roshan

    2009-11-01

    Soil aquifer treatment (SAT) and bank filtration use natural attenuation processes to purify water for subsequent use. Soil aquifer treatment may constitute both unsaturated and saturated flow conditions, while bank filtration systems are primarily saturated flow. This analysis focuses on the saturated zone, where the majority of residence time occurs, in both SAT and bank filtration systems. Sustainable removal mechanisms during subsurface flow are primarily surface-mediated and therefore depend on surface area. By analyzing saturated subsurface flow hydraulics in granular media, a relationship between surface area and travel time was developed. For saturated subsurface flow, the ratio of surface area-to-travel time varied by approximately a factor of 3, for common aquifer materials subject to identical hydraulic gradients. Because travel time criteria often are used to regulate SAT and bank filtration systems, these criteria also may determine the surface area and associated surface-mediated reactions for water purification. The ratio of surface area-to-travel time increases with increasing hydraulic gradient, implying that surface area is relatively constant for specific travel times, even if the hydraulic gradient changes; however, the increasing hydraulic gradient will increase the distance from the recharge zone to the recovery well. Therefore, travel time assessments based on maximum possible hydraulic gradients increase surface area and could provide a conservative limit for surface-mediated reactions. This analysis demonstrates that travel time criteria for SAT and bank filtration systems indirectly provide a minimum surface area that may support sustainable removal mechanisms.

  3. Surface atmospheric extremes (launch and transportation areas)

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Criteria are provided on atmospheric extremes from the surface to 150 meters for geographical locations of interest to NASA. Thermal parameters (temperature and solar radiation), humidity, precipitation, pressure, and atmospheric electricity (lightning and static) are presented. Available data are also provided for the entire continental United States for use in future space programs.

  4. Long-term outcome of amniotic membrane transplantation combined with mitomycin C for conjunctival reconstruction after ocular surface squamous neoplasia excision.

    PubMed

    Hanada, Kazuomi; Nishikawa, Noriko; Miyokawa, Naoyuki; Yoshida, Akitoshi

    2017-02-01

    The aim of the study is to evaluate the long-term clinical results of amniotic membrane transplantation (AMT) combined with mitomycin C (MMC) for reconstruction of conjunctival defects created during the excision of ocular surface squamous neoplasia (OSSN). Eight consecutive eyes of seven patients (five males and two females; mean age, 64 ± 19 years) treated by one surgeon (KH) were included in this study. AMT was performed after excision of a mass region, along with 0.04 % MMC treatment for the exposed sclera. The tumor size, histopathological retrieval, AM graft size after tumor excision, recurrence, and postoperative complications were recorded. During a mean postoperative follow-up period of 60.9 ± 14.6 months (range 36-78 months), the ocular surfaces completely re-epithelialized in all cases. The median size of the tumor was 44.4 ± 21.2 mm(2) (range 13-67 mm(2)). The histopathological diagnoses were five cases of squamous cell carcinoma in situ (SCC in situ) and three cases of dysplasia. The median size of the AM graft after tumor excision was 100.8 ± 32.7 mm(2) (range 49-151 mm(2)). A case of recurrent SCC in situ with a preoperative history of using MMC eye drops developed further corneal limbal deficiency and was treated with therapeutic soft contact lenses. A case of dysplasia with a history of large pterygial excision developed symblepharon postoperatively was treated with AMT 6 months after tumor excision. The tumors recurred in two eyes with SCC in situ and were successfully treated with continuous AMT and MMC. No severe complications, such as infections, corneal or scleral thinning, or ulceration developed in all cases. The combination of AMT and MMC is effective for safe reconstruction over the long-term after the excision of OSSN with postoperative careful observation and treatment. In recurrent tumor excision cases, AMT is a suitable technique for repeated ocular surface reconstruction.

  5. Optical coherence tomography to evaluate the interaction of different edge designs of four different silicone hydrogel lenses with the ocular surface

    PubMed Central

    Turhan, Semra Akkaya; Toker, Ebru

    2015-01-01

    Purpose To evaluate the lens edge interaction with the ocular surface with different edge designs using optical coherence tomography and to examine the effect of lens power on the lens edge interactions. Methods Four types of silicone hydrogel lenses with different edge designs (round-, semi-round-, chisel-, and knife-edged) at six different powers (+5.0, +3.0, +1.0, −1.0, −3.0, and −5.0 diopters) were fitted to both eyes of 20 healthy volunteers. Optical coherence tomography images were taken at the corneal center and at the limbus within 15–30 minutes after insertion. The images were evaluated with respect to two parameters: conjunctival indentation exerted by the lens edge; and the tear film gaps between the posterior surface of the lens and the ocular surface. The amount of conjunctival indentation was measured with the distortion angle of the conjunctiva at the lens edge. Results The degree of conjunctival indentation was highest with the chisel-edged design followed by the semi-round design (P<0.0001). Knife- and round-edged lenses exerted similar levels of conjunctival indentation that was significantly lower compared to chisel-edged lens (P<0.001). For each one of the tested lens edge designs, no significant difference was observed in the conjunctival indentation with respect to lens power. The chisel-edged lens produced the highest amount of conjunctival indentation for each one of the six lens powers (P<0.0001). Post-lens tear film gaps at the limbus were observed at most in the round-edge design (P=0.001). Conclusion The fitting properties of contact lenses may be influenced by their edge design but not by their lens power. PMID:26045658

  6. Why Do We Need the Derivative for the Surface Area?

    ERIC Educational Resources Information Center

    Hristova, Yulia; Zeytuncu, Yunus E.

    2016-01-01

    Surface area and volume computations are the most common applications of integration in calculus books. When computing the surface area of a solid of revolution, students are usually told to use the frustum method instead of the disc method; however, a rigorous explanation is rarely provided. In this note, we provide one by using geometric…

  7. Comparative assessment of the cytotoxicity of six anti-inflammatory eyedrops in four cultured ocular surface cell lines, as determined by cell viability scores

    PubMed Central

    Ayaki, Masahiko; Iwasawa, Atsuo; Niwano, Yoshimi

    2012-01-01

    Purpose Anti-inflammatory eyedrops are often used in the treatment of corneal epithelial disorders. In the present study, we evaluated the cytotoxicity of six anti-inflammatory eyedrops in four ocular surface cell lines. Methods The cytotoxicity of six commercially available anti-inflammatory ophthalmic solutions (ie, diclofenac, bromfenac, pranoprofen, betamethasone, and fluoromethorone) was assessed in three corneal cell lines and one conjunctival cell line. Cell viability was determined by the 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide and neutral red assays after exposing the cells to 10, 30, and 60 minutes of onefold, twofold, and tenfold dilutions of the drugs. Cytotoxicity was compared using the cell viability score (CVS), an integrated cytotoxic parameter that takes various factors into account, such as dilution by tear fluid or concentration by evaporation, drug exposure time, and ocular surface cell type. Results Based on the CVS scores, the order of the anti-inflammatory eyedrops tested from least to most cytotoxic, with the active ingredient %CVS50, and %CVS40/80 for each solution given in parentheses, was as follows: Rinderon® (betamethasone, 100%, 100%) >0.02% Flumethoron® (fluoromethorone, 68%, 22%) = 0.1% Flumethoron® (fluoromethorone, 76%, 22%) >Bronuck® (0.1% bromfenac, 53%, −8%) = Diclod® (0.1% diclofenac, 44%, −15%) = Niflan® (pranoprofen, 50%, −19%). Rinderon® exhibited the least toxicity of all the anti-inflammatory eyedrops tested. Eyedrops containing non-steroidal anti-inflammatory drugs exhibited greater cytotoxicity than those containing steroids with benzalkonium at comparable concentrations. Concentration was the most significant factor affecting cell viability. Conclusion The cytotoxicity of the anti-inflammatory eyedrops evaluated in the present study depended on both the pharmaceutical components and preservatives. The CVS is a concise indicator of drug cytotoxicity. PMID:23185116

  8. Influence on ocular surface after cataract surgery and effect of topical diquafosol on postoperative dry eye: a multicenter prospective randomized study

    PubMed Central

    Miyake, Kensaku; Yokoi, Norihiko

    2017-01-01

    Purpose To investigate influences of 3% diquafosol sodium ophthalmic solution (DQS) on ocular surface after cataract surgery and effects on postoperative dry eye. Design This study had two consecutive prospective study phases. The former was an observational study from before cataract surgery to 4 weeks after surgery and the latter was a randomized open-label study from 4 to 8 weeks after surgery. Methods Subjects were 433 eyes of 433 patients undergoing cataract surgery with intraocular lens implantation. Dry eye examination of tear breakup time (BUT), corneal and conjunctival fluorescein staining scores, total subjective symptom score (12 symptoms), and Schirmer I test were conducted before surgery and 4 weeks after surgery. Patient demographics and these examination results were used to analyze risk factors to predict postoperative dry eye. In a randomized study, 154 eyes diagnosed with dry eye postoperatively were applied either DQS or artificial tears (AT) six times daily for 4 weeks. The data of the examinations were compared. Results At 4 weeks after surgery, BUT was shortened significantly (P=0.036), fluorescein staining score increased significantly (P=0.012), but total subjective symptom score was significantly improved (P<0.001). The majority of postoperative dry eye was shortened BUT type (53.1%). The dry eye prevalence after surgery decreased (55.7%) compared with before surgery (69.7%). Females and the patient with dry eye symptoms before surgery had significant risk factors for postoperative dry eye. In a randomized study, BUT was significantly prolonged in the DQS group (P=0.015), but not in the AT group. Fluorescein staining score was significantly improved in both groups (P<0.001). Total subjective symptom score was significantly decreased in the AT group (P<0.001), but not in the DQS group. Conclusion Our study suggests that cataract surgery has harmful effects on tear film stability and ocular surface, and DQS has a capability to improve them

  9. Attention to surfaces modulates motion processing in extrastriate area MT.

    PubMed

    Wannig, Aurel; Rodríguez, Valia; Freiwald, Winrich A

    2007-05-24

    In the visual system, early atomized representations are grouped into higher-level entities through processes of perceptual organization. Here we present neurophysiological evidence that a representation of a simple object, a surface defined by color and motion, can be the unit of attentional selection at an early stage of visual processing. Monkeys were cued by the color of a fixation spot to attend to one of two transparent random-dot surfaces, one red and one green, which occupied the same region of space. Motion of the attended surface drove neurons in the middle temporal (MT) visual area more strongly than physically identical motion of the non-attended surface, even though both occurred within the spotlight of attention. Surface-based effects of attention persisted even without differential surface coloring, but attentional modulation was stronger with color. These results show that attention can select surface representations to modulate visual processing as early as cortical area MT.

  10. MOISTURE AND SURFACE AREA MEASUREMENTS OF PLUTONIUM-BEARING OXIDES

    SciTech Connect

    Crowder, M.; Duffey, J.; Livingston, R.; Scogin, J.; Kessinger, G.; Almond, P.

    2009-09-28

    To ensure safe storage, plutonium-bearing oxides are stabilized at 950 C for at least two hours in an oxidizing atmosphere. Stabilization conditions are expected to decompose organic impurities, convert metals to oxides, and result in moisture content below 0.5 wt%. During stabilization, the specific surface area is reduced, which minimizes readsorption of water onto the oxide surface. Plutonium oxides stabilized according to these criteria were sampled and analyzed to determine moisture content and surface area. In addition, samples were leached in water to identify water-soluble chloride impurity content. Results of these analyses for seven samples showed that the stabilization process produced low moisture materials (< 0.2 wt %) with low surface area ({le} 1 m{sup 2}/g). For relatively pure materials, the amount of water per unit surface area corresponded to 1.5 to 3.5 molecular layers of water. For materials with chloride content > 360 ppm, the calculated amount of water per unit surface area increased with chloride content, indicating hydration of hygroscopic salts present in the impure PuO{sub 2}-containing materials. The low moisture, low surface area materials in this study did not generate detectable hydrogen during storage of four or more years.

  11. Ion Channels in the Eye: Involvement in Ocular Pathologies.

    PubMed

    Giblin, Jonathan P; Comes, Nuria; Strauss, Olaf; Gasull, Xavier

    2016-01-01

    The eye is the sensory organ of vision. There, the retina transforms photons into electrical signals that are sent to higher brain areas to produce visual sensations. In the light path to the retina, different types of cells and tissues are involved in maintaining the transparency of avascular structures like the cornea or lens, while others, like the retinal pigment epithelium, have a critical role in the maintenance of photoreceptor function by regenerating the visual pigment. Here, we have reviewed the roles of different ion channels expressed in ocular tissues (cornea, conjunctiva and neurons innervating the ocular surface, lens, retina, retinal pigment epithelium, and the inflow and outflow systems of the aqueous humor) that are involved in ocular disease pathophysiologies and those whose deletion or pharmacological modulation leads to specific diseases of the eye. These include pathologies such as retinitis pigmentosa, macular degeneration, achromatopsia, glaucoma, cataracts, dry eye, or keratoconjunctivitis among others. Several disease-associated ion channels are potential targets for pharmacological intervention or other therapeutic approaches, thus highlighting the importance of these channels in ocular physiology and pathophysiology.

  12. Determination of Reactive Surface Area of Melt Glass

    SciTech Connect

    Bourcier,W.L.; Roberts, S.; Smith, D.K.; Hulsey, S.; Newton,L.; Sawvel, A.; Bruton, C.; Papelis, C.; Um, W.; Russell, C. E.; Chapman,J.

    2000-10-01

    A comprehensive investigation of natural and manmade silicate glasses, and nuclear melt glass was undertaken in order to derive an estimate of glass reactive surface area. Reactive surface area is needed to model release rates of radionuclides from nuclear melt glass in the subsurface. Because of the limited availability of nuclear melt glasses, natural volcanic glass samples were collected which had similar textures and compositions as those of melt glass. A flow-through reactor was used to measure the reactive surface area of the analog glasses in the presence of simplified NTS site ground waters. A measure of the physical surface area of these glasses was obtained using the BET gas-adsorption method. The studies on analog glasses were supplemented by measurement of the surface areas of pieces of actual melt glass using the BET method. The variability of the results reflect the sample preparation and measurement techniques used, as well as textural heterogeneity inherent to these samples. Based on measurements of analog and actual samples, it is recommended that the hydraulic source term calculations employ a range of 0.001 to 0.01 m{sup 2}/g for the reactive surface area of nuclear melt glass.

  13. Unique developmental trajectories of cortical thickness and surface area.

    PubMed

    Wierenga, Lara M; Langen, Marieke; Oranje, Bob; Durston, Sarah

    2014-02-15

    There is evidence that the timing of developmental changes in cortical volume and thickness varies across the brain, although the processes behind these differences are not well understood. In contrast to volume and thickness, the regional developmental trajectories of cortical surface area have not yet been described. The present study used a combined cross-sectional and longitudinal design with 201 MRI-scans (acquired at 1.5-T) from 135 typically developing children and adolescents. Scans were processed using FreeSurfer software and the Desikan-Killiany atlas. Developmental trajectories were estimated using mixed model regression analysis. Within most regions, cortical thickness showed linear decreases with age, whereas both cortical volume and surface area showed curvilinear trajectories. On average, maximum surface area occurred later in development than maximum volume. Global gender differences were more pronounced in cortical volume and surface area than in average thickness. Our findings suggest that developmental trajectories of surface area and thickness differ across the brain, both in their pattern and their timing, and that they also differ from the developmental trajectory of global cortical volume. Taken together, these findings indicate that the development of surface area and thickness is driven by different processes, at least in part.

  14. Location of Tessellations in Ocular Fundus and Their Associations with Optic Disc Tilt, Optic Disc Area, and Axial Length in Young Healthy Eyes

    PubMed Central

    Terasaki, Hiroto; Yamashita, Takehiro; Yoshihara, Naoya; Kii, Yuya; Tanaka, Minoru; Nakao, Kumiko; Sakamoto, Taiji

    2016-01-01

    Tessellated fundus is found as common and early-phase characteristic of myopic eyes and their locations are varied among patients. However, the relationship between their locations and morphological parameters of the eyes is still unknown. The purpose is this study is to determine the locations of the tessellations in the ocular fundus of young healthy eyes, and to determine relationships between their locations and morphological parameters of the eyes. This is a prospective observational cross sectional study of 126 eyes of 126 healthy volunteers (mean age 26.0±4.1 years). The eyes were classified into eight groups based on the location of the tessellations; no tessellation, temporal, infra-temporal, inferior, nasal, peripapillary, whole retina, and unclassified tessellations. The degree of optic disc tilt was quantified using a sine curve fitting program on the optical coherence tomographic circle scan images. The correlations between each tessellation location and the axial length, area of the optic disc plus conus (AOC), and optic disc tilt were determined. Forty-four eyes were place in the no tessellation group, 12 eyes in the temporal, 21 eyes in the infra-temporal, 9 eyes in the inferior, 8 eyes in the nasal, 15 eyes in the peripapillary, 11 eyes in the whole, and 6 eyes in the unclassified groups. The differences in the axial lengths between the no tessellation group and the infra-temporal groups were significant. A significant difference was found in the AOC between the no tessellation and the inferior, infra-temporal, and peripapilalry groups. A significant difference was found in the optic disc tilt between the no tessellation and infra-temporal groups (P<0.05). The tessellations are located at specific sites in the fundus of young healthy eyes with the infra-temporal location most frequent. It was correlated with some parameters associated with myopia. PMID:27275584

  15. The Easiest Children to Reach Are Most Likely to Be Infected with Ocular Chlamydia trachomatis in Trachoma Endemic Areas of Niger

    PubMed Central

    Amza, Abdou; Kadri, Boubacar; Nassirou, Baido; Yu, Sun N.; Stoller, Nicole E.; Bhosai, Satasuk J.; Zhou, Zhaoxia; McCulloch, Charles E.; West, Sheila K.; Bailey, Robin L.; Keenan, Jeremy D.; Lietman, Thomas M.; Gaynor, Bruce D.

    2013-01-01

    Background Control programs for trachoma use mass antibiotic distributions to treat ocular Chlamydia trachomatis in an effort to eliminate this disease worldwide. To determine whether children infected with ocular Chlamydia are more likely to present later for examination than those who are uninfected, we compare the order of presentation for examination of children 0–5 years, and the presence of ocular Chlamydia by PCR in 4 villages in Niger where trachoma is endemic. Methods We conducted a cluster-randomized, controlled trial where 48 randomly selected villages in Niger are divided into 4 study arms of different mass treatment strategies. In a substudy of the main trial, we randomly selected 1 village from each of the 4 study arms (4 total villages) and we evaluated the odds of ocular Chlamydia versus the rank order of presentation for examination and laboratory assessment before treatment was offered. Findings We found the odds of harboring ocular Chlamydia dropped by more than 70% from the first child examined to the last child examined (OR 0.27, 95% CI 0.13–0.59, P = 0.001) in the 4 randomly selected villages. We found the odds of active trachoma dropped by 80% from the first child examined to the last child examined (OR 0.20, 95% CI 0.10–0.4, P<0.0001) in the 48 villages in the main trial. Interpretation This study demonstrates that even if the WHO recommended 80% treatment coverage is not reached in certain settings, children 0–5 years with the greatest probability of ocular Chlamydia have higher odds of receiving attention because they are the first to present. These results suggest there may be diminishing returns when using scarce resources to track down the last few children in a mass treatment program. Trial Registration ClinicalTrials.gov NCT00792922 PMID:23326612

  16. Quantifying object and material surface areas in residences

    SciTech Connect

    Hodgson, Alfred T.; Ming, Katherine Y.; Singer, Brett C.

    2005-01-05

    The dynamic behavior of volatile organic compounds (VOCs) in indoor environments depends, in part, on sorptive interactions between VOCs in the gas phase and material surfaces. Since information on the types and quantities of interior material surfaces is not generally available, this pilot-scale study was conducted in occupied residences to develop and demonstrate a method for quantifying surface areas of objects and materials in rooms. Access to 33 rooms in nine residences consisting of bathrooms, bedroom/offices and common areas was solicited from among research group members living in the East San Francisco Bay Area. A systematic approach was implemented for measuring rooms and objects from 300 cm{sup 2} and larger. The ventilated air volumes of the rooms were estimated and surface area-to-volume ratios were calculated for objects and materials, each segregated into 20 or more categories. Total surface area-to-volume ratios also were determined for each room. The bathrooms had the highest total surface area-to-volume ratios. Bedrooms generally had higher ratios than common areas consisting of kitchens, living/dining rooms and transitional rooms. Total surface area-to-volume ratios for the 12 bedrooms ranged between 2.3 and 4.7 m{sup 2} m{sup -3}. The importance of individual objects and materials with respect to sorption will depend upon the sorption coefficients for the various VOC/materials combinations. When combined, the highly permeable material categories, which may contribute to significant interactions, had a median ratio of about 0.5 m{sup 2} m{sup -3} for all three types of rooms.

  17. Minimal adhesion surface area in tangentially loaded digital contacts.

    PubMed

    Terekhov, Alexander V; Hayward, Vincent

    2011-09-02

    The stick-to-slip transition of a fingertip in contact with a planar surface does not occur instantaneously. As the tangential load increases, portions of the skin adhere while others slip, giving rise to an evolution of the contact state, termed partial slip. We develop a quasi-static model that predicts that if the coefficient of kinetic friction is larger than the coefficient of static friction, then the stuck surface area diminishes as the tangential load increases until reaching a 'minimal adhesion surface area' where it vanishes abruptly. This phenomenon was observed in recently measured finger-slip image data (André et al., 2011) that were processed by an optic flow detection algorithm. We examined the results of 10 trials. Four of them exhibited the minimal adhesion surface area phenomenon, four of them did not, and two were inconclusive.

  18. Segmentation-free ocular detection and recognition

    NASA Astrophysics Data System (ADS)

    Rodriguez, Andres; Panza, Jeffrey; Vijaya Kumar, B. V. K.

    2011-06-01

    Iris recognition is a well-known technique to identify persons. However this technique requires high resolution images in order to automatically segment the iris. In some scenarios obtaining the required resolution may be difficult. In this paper, we investigate the recognition of ocular regions using correlation filters without segmenting the iris region. This method uses the whole eye region and surrounding areas, i.e., the ocular region, for identification. In our experiments we use the recently developed Quadratic Correlation Filter and show that at low resolutions segmentation-free ocular recognition can succeed while iris segmentation fails.

  19. Ultraviolet light and ocular diseases.

    PubMed

    Yam, Jason C S; Kwok, Alvin K H

    2014-04-01

    The objective of this study is to review the association between ultraviolet (UV) light and ocular diseases. The data are sourced from the literature search of Medline up to Nov 2012, and the extracted data from original articles, review papers, and book chapters were reviewed. There is a strong evidence that ultraviolet radiation (UVR) exposure is associated with the formation of eyelid malignancies [basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)], photokeratitis, climatic droplet keratopathy (CDK), pterygium, and cortical cataract. However, the evidence of the association between UV exposure and development of pinguecula, nuclear and posterior subcapsular cataract, ocular surface squamous neoplasia (OSSN), and ocular melanoma remained limited. There is insufficient evidence to determine whether age-related macular degeneration (AMD) is related to UV exposure. It is now suggested that AMD is probably related to visible radiation especially blue light, rather than UV exposure. From the results, it was concluded that eyelid malignancies (BCC and SCC), photokeratitis, CDK, pterygium, and cortical cataract are strongly associated with UVR exposure. Evidence of the association between UV exposure and development of pinguecula, nuclear and posterior subcapsular cataract, OSSN, and ocular melanoma remained limited. There is insufficient evidence to determine whether AMD is related to UV exposure. Simple behaviural changes, appropriate clothing, wearing hats, and UV blocking spectacles, sunglasses or contact lens are effective measures for UV protection.

  20. A framework for predicting surface areas in microporous coordination polymers.

    PubMed

    Schnobrich, Jennifer K; Koh, Kyoungmoo; Sura, Kush N; Matzger, Adam J

    2010-04-20

    A predictive tool termed the linker to metal cluster (LiMe) ratio is introduced as a method for understanding surface area in microporous coordination polymers (MCPs). Calibrated with geometric accessible surface area computations, the LiMe ratio uses molecular weight of building block components to indicate the maximum attainable surface area for a given linker and metal cluster combination. MOF-5 and HKUST-1 are used as prototypical structures to analyze MCPs with octahedral M(4)O(CO(2)R)(6) and paddlewheel M(2)(CO(2)R)(4) metal clusters. Insight into the effects of linker size, geometry, number of coordinating groups, and framework interpenetration is revealed through the LiMe ratio analysis of various MCPs. Experimental surface area deviation provides indication that a material may suffer from incomplete guest removal, structural collapse, or interpenetration. Because minimal data input are required, the LiMe ratio surface area analysis is suggested as a quick method for experimental verification as well as a guide for the design of new materials.

  1. Ocular histoplasmosis syndrome.

    PubMed

    Diaz, Rocio I; Sigler, Eric J; Rafieetary, Mohammad R; Calzada, Jorge I

    2015-01-01

    Ocular histoplasmosis syndrome (OHS) is a chorioretinal disorder with a distinct fundus appearance that is commonly found in regions endemic for Histoplasma capsulatum. Choroidal neovascularization (CNV) secondary to OHS is considered one of the principal causes of central vision loss among young adults in endemic areas. Although there is no consensus regarding its pathogenesis, evidence points to Histoplasma capsulatum as the most probable etiology. Once considered an intractable hemorrhagic maculopathy, CNVs are now treatable. Extrafoveal CNVs are successfully treated with laser photocoagulation. Subfoveal and juxtafoveal CNVs are managed with anti-vascular endothelial growth factor therapy, photodynamic therapy, or a combination of both. Modern imaging technologies such as spectral-domain optical coherence tomography have improved our diagnostic abilities, making it easier to monitor disease activity and CNV regression. We review the epidemiology, pathogenesis, clinical manifestations, differential diagnosis, and current treatment of this disease.

  2. Intracorneal and Intraocular Invasion of Ocular Surface Squamous Neoplasia after Intraocular Surgery: Report of Two Cases and Review of the Literature

    PubMed Central

    Murillo, Juan C.; Galor, Anat; Wu, Michael C.; Kye, Natasha K.; Wong, James; Ahmed, Ibrahim O.; Joag, Madhura; Shalabi, Nabeel; Lahners, William; Dubovy, Sander; Karp, Carol L.

    2017-01-01

    Purpose The aim of this paper was to describe 2 cases of ocular surface squamous neoplasia (OSSN) of the conjunctiva with intracorneal and intraocular extension following intraocular surgery. Methods We conducted a clinical pathological retrospective case series. Results Case 1 underwent cataract surgery in the setting of an unnoticed adjacent OSSN. An excisional biopsy with cryotherapy and intraoperative mitomycin C was subsequently performed, confirming OSSN. The patient had two recurrences treated topically with resolution. While the conjunctiva remained clear, a corneal haze emanating from the cataract incision site was noted. Penetrating keratoplasty (PK) for this haze revealed midstromal infiltrative carcinoma. Case 2 had a history of herpes simplex keratitis that ultimately required corneal grafts. Fifteen years later, he developed an OSSN treated with excisional biopsy and had clear margins. Eight months later, he presented with a recurrence of his OSSN and was treated briefly with topical interferon for 4 weeks; however, he developed an infectious keratitis with a corneal perforation requiring another PK. Four months after PK, low-grade inflammation was noted. Cytology of the anterior chamber aspirate revealed neoplastic squamous cells. Another PK was then performed. Pathology confirmed extensive intraocular neoplasia. Limited exenteration was performed. Conclusion Patients with a history of OSSN may be at increased risk of neoplastic intraocular extension following intraocular surgery. PMID:28275607

  3. Observed Asteroid Surface Area in the Thermal Infrared

    NASA Astrophysics Data System (ADS)

    Nugent, C. R.; Mainzer, A.; Masiero, J.; Wright, E. L.; Bauer, J.; Grav, T.; Kramer, E.; Sonnett, S.

    2017-02-01

    The rapid accumulation of thermal infrared observations and shape models of asteroids has led to increased interest in thermophysical modeling. Most of these infrared observations are unresolved. We consider what fraction of an asteroid’s surface area contributes the bulk of the emitted thermal flux for two model asteroids of different shapes over a range of thermal parameters. The resulting observed surface in the infrared is generally more fragmented than the area observed in visible wavelengths, indicating high sensitivity to shape. For objects with low values of the thermal parameter, small fractions of the surface contribute the majority of thermally emitted flux. Calculating observed areas could enable the production of spatially resolved thermal inertia maps from non-resolved observations of asteroids.

  4. High surface area electrode for high efficient microbial electrosynthesis

    NASA Astrophysics Data System (ADS)

    Nie, Huarong; Cui, Mengmeng; Lu, Haiyun; Zhang, Tian; Russell, Thomas; Lovley, Derek

    2012-02-01

    Microbial electrosynthesis, a process in which microorganisms directly accept electrons from an electrode to convert carbon dioxide and water into multi carbon organic compounds, affords a novel route for the generation of valuable products from electricity or even wastewater. The surface area of the electrode is critical for high production. A biocompatible, highly conductive, three-dimensional cathode was fabricated from a carbon nanotube textile composite to support the microorganism to produce acetate from carbon dioxide. The high surface area and macroscale porous structure of the intertwined CNT coated textile ?bers provides easy microbe access. The production of acetate using this cathode is 5 fold larger than that using a planar graphite electrode with the same volume. Nickel-nanowire-modified carbon electrodes, fabricated by microwave welding, increased the surface area greatly, were able to absorb more bacteria and showed a 1.5 fold increase in performance

  5. Evolution of the surface area of a snow layer

    SciTech Connect

    Hanot, L.; Domine, F.

    1999-12-01

    Atmospheric trace gases can partition between the atmosphere and the snow surface. Because snow has a large surface-to-volume ratio, an important interaction potential between ice and atmospheric trace gases exists. Quantifying this partitioning requires the knowledge of the surface area (SA) of snow. Eleven samples were taken from a 50 cm thick snow fall at Col de Porte, near Grenoble (French Alps) between January 20 and February 4, 1998. Fresh snow and 3, 8, and 15-day-old snow were sampled at three different depths. Surface hoar, formed after the fall, was also sampled. Air and surface snow temperature, snow density, and snow fall rate were measured. Snow temperature always remained below freezing. Snow SA was measured using methane adsorption at 77.15 K. Values ranged from 2.25 m{sup 2}/g for fresh snow to 0.25 m{sup 2}/g for surface hoar and surface snow after 15 days. These values are much too high to be explained by the macroscopic aspect of snow crystals, and microstructures such as small rime droplets must have been present. Large decrease in SA with time were observed. The first meter of snowpack had a total surface area of about 50,000 m{sup 2} per m{sup 2} of ground. Reduction in SA will lead to the emission of adsorbed species by the snowpack, with possible considerable increase in atmospheric concentrations.

  6. Electrochemical capacitors utilizing low surface area carbon fiber

    SciTech Connect

    Lipka, S.M.

    1997-12-01

    The performance of electrochemical capacitors containing different commercial carbon fibers is reviewed. High specific capacitances (ca. 300 F/g) are obtained with low surface area carbon fiber (<1 m2/g) using a proprietary activation process. Capacitance is primarily achieved through pseudocapacitance resulting from surface functional groups. The performance of these devices is dependent on the type of carbon fiber, its carbon content, aspect ratio and microstructure. These devices can achieve high cycle life (ca. 100k) without significant loss in capacitance.

  7. Effective surface areas of coals measured by dye adsorption

    SciTech Connect

    Spitzer, D.P.

    1988-01-01

    The primary interest has been to examine adsorption behavior especially at short contact times, ten minutes to an hour, to determine whether such measurements might give useful data on effective surface areas - i.e., the surface that would be accessible to reagents within times comparable to those typical of most coal processing. Accordingly, most of the emphasis is on the effect of time on adsorption, rather than on traditional adsorption isotherms. Although most literature on cationic dye adsorption (mostly on carbons) uses methylene blue, it happened that the authors originally used safranin O instead because this dye was reported to be useful in distinguishing oxidized coals from fresh coals. Many of their experiments were repeated using methylene blue (in water), with very similar results. It was noted early that swelling of coals in water was common, especially for more oxidized or lower rank coals, and adsorption experiments were also done in another solvent, namely methanol. This produced quite striking differences for some coals. Coal surfaces that are readily accessible to adsorption by safranin are found to correlate well with N/sub 2/ surface areas, with adsorption of 1.0 mg safranin per gram of coal corresponding to essentially a surface area of 1.0 m/sup 2//g. Highly oxidized coals were found to swell considerably in water, with correspondingly increased adsorption. Areas of such coals can be estimated by adsorption of safranin from methanol solutions.

  8. High surface area carbon and process for its production

    DOEpatents

    Romanos, Jimmy; Burress, Jacob; Pfeifer, Peter; Rash, Tyler; Shah, Parag; Suppes, Galen

    2016-12-13

    Activated carbon materials and methods of producing and using activated carbon materials are provided. In particular, biomass-derived activated carbon materials and processes of producing the activated carbon materials with prespecified surface areas and pore size distributions are provided. Activated carbon materials with preselected high specific surface areas, porosities, sub-nm (<1 nm) pore volumes, and supra-nm (1-5 nm) pore volumes may be achieved by controlling the degree of carbon consumption and metallic potassium intercalation into the carbon lattice during the activation process.

  9. Large area, surface discharge pumped, vacuum ultraviolet light source

    DOEpatents

    Sze, Robert C.; Quigley, Gerard P.

    1996-01-01

    Large area, surface discharge pumped, vacuum ultraviolet (VUV) light source. A contamination-free VUV light source having a 225 cm.sup.2 emission area in the 240-340 nm region of the electromagnetic spectrum with an average output power in this band of about 2 J/cm.sup.2 at a wall-plug efficiency of approximately 5% is described. Only ceramics and metal parts are employed in this surface discharge source. Because of the contamination-free, high photon energy and flux, and short pulse characteristics of the source, it is suitable for semiconductor and flat panel display material processing.

  10. Large area, surface discharge pumped, vacuum ultraviolet light source

    DOEpatents

    Sze, R.C.; Quigley, G.P.

    1996-12-17

    Large area, surface discharge pumped, vacuum ultraviolet (VUV) light source is disclosed. A contamination-free VUV light source having a 225 cm{sup 2} emission area in the 240-340 nm region of the electromagnetic spectrum with an average output power in this band of about 2 J/cm{sup 2} at a wall-plug efficiency of approximately 5% is described. Only ceramics and metal parts are employed in this surface discharge source. Because of the contamination-free, high photon energy and flux, and short pulse characteristics of the source, it is suitable for semiconductor and flat panel display material processing. 3 figs.

  11. Determining Surface Roughness in Urban Areas Using Lidar Data

    NASA Technical Reports Server (NTRS)

    Holland, Donald

    2009-01-01

    An automated procedure has been developed to derive relevant factors, which can increase the ability to produce objective, repeatable methods for determining aerodynamic surface roughness. Aerodynamic surface roughness is used for many applications, like atmospheric dispersive models and wind-damage models. For this technique, existing lidar data was used that was originally collected for terrain analysis, and demonstrated that surface roughness values can be automatically derived, and then subsequently utilized in disaster-management and homeland security models. The developed lidar-processing algorithm effectively distinguishes buildings from trees and characterizes their size, density, orientation, and spacing (see figure); all of these variables are parameters that are required to calculate the estimated surface roughness for a specified area. By using this algorithm, aerodynamic surface roughness values in urban areas can then be extracted automatically. The user can also adjust the algorithm for local conditions and lidar characteristics, like summer/winter vegetation and dense/sparse lidar point spacing. Additionally, the user can also survey variations in surface roughness that occurs due to wind direction; for example, during a hurricane, when wind direction can change dramatically, this variable can be extremely significant. In its current state, the algorithm calculates an estimated surface roughness for a square kilometer area; techniques using the lidar data to calculate the surface roughness for a point, whereby only roughness elements that are upstream from the point of interest are used and the wind direction is a vital concern, are being investigated. This technological advancement will improve the reliability and accuracy of models that use and incorporate surface roughness.

  12. A Novel Method for Preparing Surface-Modified Fluocinolone Acetonide Loaded PLGA Nanoparticles for Ocular Use: In Vitro and In Vivo Evaluations.

    PubMed

    Salama, Alaa H; Mahmoud, Azza A; Kamel, Rabab

    2016-10-01

    Our objective was to prepare nanoparticulate system using a simple yet attractive innovated method as an ophthalmic delivery system for fluocinolone acetonide to improve its ocular bioavailability. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles were prepared by adopting thin film hydration method using PLGA/poloxamer 407 in weight ratios of 1:5 and 1:10. PLGA was used in 75/25 and 50/50 copolymer molar ratio of DL-lactide/glycolide. Results revealed that using PLGA with lower glycolic acid monomer ratio exhibited high particle size (PS), zeta potential (ZP) and drug encapsulation efficiency (EE) values with slow drug release pattern. Also, doubling the drug concentration during nanoparticles preparation ameliorated its EE to reach almost 100%. Furthermore, studies for separating the un-entrapped drug in nanoparticles using centrifugation method at 20,000 rpm for 30 min showed that the separated clear supernatant contained nanoparticles encapsulating an important drug amount. Therefore, separation of un-entrapped drug was carried out by filtrating the preparation using 20-25 μm pore size filter paper to avoid drug loss. Aiming to increase the PLGA nanoparticles mucoadhesion ability, surface modification of selected formulation was done using different amount of stearylamine and chitosan HCl. Nanoparticles coated with 0.1% w/v chitosan HCl attained most suitable results of PS, ZP and EE values as well as high drug release properties. Transmission electron microphotographs illustrated the deposition of chitosan molecules on the nanoparticles surfaces. Pharmacokinetic studies on Albino rabbit's eyes using HPLC indicated that the prepared novel chitosan-coated PLGA nanoparticles subjected to separation by filtration showed rapid and extended drug delivery to the eye.

  13. Estimating 3-dimensional colony surface area of field corals

    EPA Science Inventory

    Colony surface area is a critical descriptor for biological and physical attributes of reef-building (scleractinian, stony) corals. The three-dimensional (3D) size and structure of corals are directly related to many ecosystem values and functions. Most methods to estimate colony...

  14. Increasing biochar surface area: effects of various milling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar produced from corn stover is a renewable, plentiful source of carbon that is a potential substitute for carbon black as rubber composite filler and also as binder/filter media for water or beverage purification applications. However, to be successful in these applications, the surface area o...

  15. Increasing biochar surface area: Optimization of ball milling parameters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar produced from corn stover is a renewable, plentiful source of carbon that is a potential substitute for carbon black as rubber composite filler and also as binder/filter media for water or beverage purification applications. However, to be successful in these applications, the surface area o...

  16. Interface Surface Area Tracking for the Conservative Level Set Method

    NASA Astrophysics Data System (ADS)

    Firehammer, Stephanie; Desjardins, Olivier

    2015-11-01

    One key question in liquid-gas flows is how to model the interface between phases in a way that is mass, momentum, and energy conserving. The accurate conservative level set (ACLS) method of Desjardins et al. provides a tool for tracking a liquid-gas interface with minimal mass conservation issues; however, it does not explicitly compute the interface surface area and thus nothing can be said a priori about the balance between kinetic energy and surface energy. This work examines an equation for the transport of interface surface area density, which can be written in terms of the gradient of the volume fraction. Furthermore this presentation will outline a numerical method for jointly transporting a conservative level set and surface area density. Finally, we will explore oppportunities for energy conservation via the accurate exchange of energy between the flow field and the interface through surface tension, with test cases to show the results of our extended ACLS method. Funding from the National Science Foundation is gratefully acknowledged.

  17. Effect of milling temperatures on surface area, surface energy and cohesion of pharmaceutical powders.

    PubMed

    Shah, Umang V; Wang, Zihua; Olusanmi, Dolapo; Narang, Ajit S; Hussain, Munir A; Tobyn, Michael J; Heng, Jerry Y Y

    2015-11-10

    Particle bulk and surface properties are influenced by the powder processing routes. This study demonstrates the effect of milling temperatures on the particle surface properties, particularly surface energy and surface area, and ultimately on powder cohesion. An active pharmaceutical ingredient (API) of industrial relevance (brivanib alaninate, BA) was used to demonstrate the effect of two different, but most commonly used milling temperatures (cryogenic vs. ambient). The surface energy of powders milled at both cryogenic and room temperatures increased with increasing milling cycles. The increase in surface energy could be related to the generation of surface amorphous regions. Cohesion for both cryogenic and room temperature milled powders was measured and found to increase with increasing milling cycles. For cryogenic milling, BA had a surface area ∼ 5× higher than the one obtained at room temperature. This was due to the brittle nature of this compound at cryogenic temperature. By decoupling average contributions of surface area and surface energy on cohesion by salinization post-milling, the average contribution of surface energy on cohesion for powders milled at room temperature was 83% and 55% at cryogenic temperature.

  18. Potential applications of ocular thermography.

    PubMed

    Morgan, P B; Soh, M P; Efron, N; Tullo, A B

    1993-07-01

    Thermography is an investigative technique which allows rapid color-coded display of the temperature across a wide surface by means of infrared detection. We describe an ocular thermographic study of a normal population and present case studies describing the application of this technique for patients with ocular disease. We found that 95% of the normal population have an interocular temperature difference (temperature of center of right cornea minus temperature of center of left cornea) of 0.60 degrees or less. There appears to be a greater difference in temperature between the limbus and the center of the cornea in patients with dry eyes. This technique has potential for evaluating tear film disorders and inflammatory conditions, for monitoring the progress of such conditions, and for evaluating the efficacy of various treatments.

  19. Plasma rich in growth factors (PRGF) eye drops stimulates scarless regeneration compared to autologous serum in the ocular surface stromal fibroblasts.

    PubMed

    Anitua, E; de la Fuente, M; Muruzabal, F; Riestra, A; Merayo-Lloves, J; Orive, G

    2015-06-01

    Autologous serum (AS) eye drops was the first blood-derived product used for the treatment of corneal pathologies but nowadays PRGF arises as a novel interesting alternative to this type of diseases. The purpose of this study was to evaluate and compare the biological outcomes of autologous serum eye drops or Plasma rich in growth factors (PRGF) eye drops on corneal stromal keratocytes (HK) and conjunctival fibroblasts (HConF). To address this, blood from healthy donors was collected and processed to obtain autologous serum (AS) eye drops and plasma rich in growth factors (PRGF) eye drops. Blood-derivates were aliquoted and stored at -80°C until use. PDGF-AB, VEGF, EGF, FGFb and TGF-β1 were quantified. The potential of PRGF and AS in promoting wound healing was evaluated by means of proliferation and migration assays in HK and HConF. Fibroblast cells were induced to myofibroblast differentiation after treatment with 2.5ng/mL of TGF-β1. The capability of PRGF and AS to prevent and inhibit TGF-β1-induced differentiation was evaluated. Results showed significant higher levels of all growth factors analyzed in PRGF eye drops compared to AS. Moreover, PRGF eye drops enhanced significantly the biological outcomes of both HK and HConF, and reduced TGF-β1-induced myofibroblast differentiation in contrast to autologous serum eye drops (AS). In summary, these results suggest that PRGF exerts enhanced biological outcomes than AS. PRGF may improve the treatment of ocular surface wound healing minimizing the scar formation compared to AS. Results obtained herein suggest that PRGF protects and reverses the myofibroblast phenotype while promotes cell proliferation and migration.

  20. Excess surface area in bioelectrochemical systems causes ion transport limitations

    PubMed Central

    Harrington, Timothy D.; Babauta, Jerome T.; Davenport, Emily K.; Renslow, Ryan S.; Beyenal, Haluk

    2014-01-01

    We investigated ion transport limitations on 3D graphite felt electrodes by growing Geobacter sulfurreducens biofilms with advection to eliminate external mass transfer limitations. We characterized ion transport limitations by: 1) showing that serially increasing NaCl concentration up to 200 mM increased current linearly up to a total of +273% vs. 0 mM NaCl under advective conditions, 2) growing the biofilm with a starting concentration of 200 mM NaCl, which led to a maximum current increase of 400% vs. current generation without NaCl, and 3) showing that un-colonized surface area remained even after steady-state current was reached. After accounting for iR effects, we confirmed that the excess surface area existed despite a non-zero overpotential at the electrode surface. The fact that the biofilm was constrained from colonizing and producing further current under these conditions confirmed the biofilms under study here were ion transport-limited. Our work demonstrates that the use of high surface area electrodes may not increase current density when the system design allows ion transport limitations to become dominant. PMID:25421463

  1. Surface area and conductivity of polyaniline synthesized under UV irradiation

    NASA Astrophysics Data System (ADS)

    Budi, S.; Fitri, E.; Paristiowati, M.; Cahyana, U.; Pusparini, E.; Nasbey, H.; Imaddudin, A.

    2017-02-01

    This paper reports our study on the synthesis of high electrical conductivity and surface area polyaniline using oxidative polymerization under UV light irradiation. The formation of emeraldine structures of polyaniline was revealed by major absorption bands of FTIR (Fourier transform infrared spectroscopy) spectra attributed to C-N stretching, C=C stretching in the benzenoid ring, C=C stretching in the quinoid ring and QNH+B stretching. XRD (X-ray diffractometer) measurements confirmed typical diffraction patterns with a crystallinity of 13% and 16% for polyaniline prepared under non-stirred and stirred reaction, respectively. SEM (Scanning electron microscope) studies showed more uniform morphology of polyaniline was obtained with stirring reaction process compare to those prepared without stirring. Surface analysis using SAA (surface area analyzer) showed that pure polyaniline with the relatively high surface area of ca.28 m2/g was successfully prepared in this work. Based on four point probe measurement, the prepared polyaniline possesses high conductivity which is important in electrode application.

  2. A fast pairwise evaluation of molecular surface area.

    PubMed

    Vasilyev, Vladislav; Purisima, Enrico O

    2002-05-01

    A fast and general analytical approach was developed for the calculation of the approximate van der Waals and solvent-accessible surface areas. The method is based on three basic ideas: the use of the Lorentz transformation formula, a rigid-geometry approximation, and a single fitting parameter that can be refitted on the fly during a simulation. The Lorentz transformation equation is used for the summation of the areas of an atom buried by its neighboring contacting atoms, and implies that a sum of the buried pairwise areas cannot be larger than the surface area of the isolated spherical atom itself. In a rigid-geometry approximation we numerically calculate and keep constant the surface of each atom buried by the atoms involved in 1-2 and 1-3 interactions. Only the contributions from the nonbonded atoms (1-4 and higher interactions) are considered in terms of the pairwise approximation. The accuracy and speed of the method is competitive with other pairwise algorithms. A major strength of the method is the ease of parametrization.

  3. Tropical cyclone rainfall area controlled by relative sea surface temperature

    PubMed Central

    Lin, Yanluan; Zhao, Ming; Zhang, Minghua

    2015-01-01

    Tropical cyclone rainfall rates have been projected to increase in a warmer climate. The area coverage of tropical cyclones influences their impact on human lives, yet little is known about how tropical cyclone rainfall area will change in the future. Here, using satellite data and global atmospheric model simulations, we show that tropical cyclone rainfall area is controlled primarily by its environmental sea surface temperature (SST) relative to the tropical mean SST (that is, the relative SST), while rainfall rate increases with increasing absolute SST. Our result is consistent with previous numerical simulations that indicated tight relationships between tropical cyclone size and mid-tropospheric relative humidity. Global statistics of tropical cyclone rainfall area are not expected to change markedly under a warmer climate provided that SST change is relatively uniform, implying that increases in total rainfall will be confined to similar size domains with higher rainfall rates. PMID:25761457

  4. Laser exposure analysis for a near-infrared ocular interferometer

    NASA Astrophysics Data System (ADS)

    Primeau, Brian C.; Goldstein, Goldie L.; Greivenkamp, John E.

    2012-06-01

    Ocular interferometry has potential value in a variety of ocular measurement applications, including measuring ocular thicknesses, topography of ocular surfaces or the wavefront of the eye. Of particular interest is using interferometry for characterizing corneal shape and irregular corneal features, making this technology attractive due to its inherent accuracy and spatial resolution. A particular challenge of designing an ocular interferometer is determining safe laser exposure levels to the eye, including both the retina and anterior segment. Described here are the laser exposure standards relevant in the interferometer design and the corresponding calculations and results. The results of this work can be used to aid in the design of similar laser-based systems for ocular evaluation.

  5. Ocular shell structures in some Cretaceous trachyleberid Ostracoda

    USGS Publications Warehouse

    Kontrovitz, M.; Puckett, T.M.

    1998-01-01

    This is the first study of internal ocular shell structures of Cretaceous ostracodes. Internal molds from eight species of four genera from Santonian, Campanian, and Maastrichtian strata revealed a stalked ocular sinus constricted along its length and distally inflated. The latter part has anterior and posterior lobes and a subcentral concavity. These Cretaceous trachyleberids have ocular shell structures similar to Cenozoic taxa and it is presumed they functioned similarly. However, each taxon has a diagnostic ocular sinus and an inner surface of the eye tubercle that distinguishes each from all other forms examined.

  6. High Surface Area Nanoporous Polymers for Reversible HydrogenStorage

    SciTech Connect

    Germain, Jonathan; Hradil, Jiri; Frechet, Jean M.J.; Svec,Frantisek

    2006-06-29

    Hydrogen adsorption using a series of nanoporous synthetic polymers has been studied. Promising results were obtained during the screening of commercially available porous polymer beads; of the polymers considered, hypercrosslinked Hypersol-Macronet MN200 resin exhibited the highest adsorption capacity for hydrogen. This initial success triggered the development of our own high surface area hypercrosslinked materials. Subjecting gel-type and macroporous vinylbenzyl chloride-based precursors swollen in dichloroethane to a Friedel-Crafts reaction catalyzed by iron trichloride afforded beads with surface areas of 1 930 and 1 300 m{sup 2}/g, respectively, as calculated using the BET equation. The former polymer reversibly stores up to 1.5 wt % H{sub 2} at a pressure of 0.12 MPa and a temperature of 77.3 K. The initial heat of adsorption of hydrogen molecules onto this polymer is 6.6 kJ/mol.

  7. High Surface Area Inorganic Membrane for Water Removal

    SciTech Connect

    2008-12-01

    This factsheet describes a research project whose objective is to demonstrate the fabrication and performance advantages of minichannel planar membrane modules made of porous metallic supports of surface area packing density one order of magnitude higher than the conventional membrane tube. The new, transformational, ceramic/metallic, hybrid membrane technology will be used for water/ethanol separations and reduce energy consumption by >20% over distillation and adsorption.

  8. Excess Surface Area in Bioelectrochemical Systems Causes ion Transport Limitations

    SciTech Connect

    Harrington, Timothy D.; Babauta, Jerome T.; Davenport, Emily K.; Renslow, Ryan S.; Beyenal, Haluk

    2015-05-01

    We investigated ion transport limitations on 3D graphite felt electrodes by growing Geobacter sulfurreducens biofilms with advection to eliminate external mass transfer limitations. We characterized ion transport limitations by: (i) showing that serially increasing NaCl concentration up to 200mM increased current linearly up to a total of þ273% vs. 0mM NaCl under advective conditions; (ii) growing the biofilm with a starting concentration of 200mM NaCl, which led to a maximum current increase of 400% vs. current generation without NaCl, and (iii) showing that un-colonized surface area remained even after steadystate current was reached. After accounting for iR effects, we confirmed that the excess surface area existed despite a non-zero overpotential. The fact that the biofilm was constrained from colonizing and producing further current under these conditions confirmed the biofilms under study here were ion transport-limited. Our work demonstrates that the use of high surface area electrodes may not increase current density when the system design allows ion transport limitations to become dominant.

  9. Solvothermal synthesis of ceria nanoparticles with large surface areas

    SciTech Connect

    Hosokawa, S.; Shimamura, K.; Inoue, M.

    2011-11-15

    Highlights: {yields} Thermal decomposition of Ce(C{sub 7}H{sub 15}COO){sub 3}.xH{sub 2}O synthesized by solvothermal method. {yields} CeO{sub 2} having an extremely large surface area of 180 m{sup 2}/g. {yields} High catalytic activity of Ru catalyst supported on the CeO{sub 2} having high surface area. -- Abstract: Ceria nanoparticles were obtained by the calcination of precursors synthesised via the solvothermal reaction of cerium acetate. The CeO{sub 2} samples obtained by the thermal decomposition of Ce(C{sub 7}H{sub 15}COO){sub 3}.xH{sub 2}O synthesised by solvothermal reaction in 1,4-butanediol in the presence of octanoic acid had an extremely large surface area of 180 m{sup 2}/g. The Ru catalyst supported on this CeO{sub 2} sample showed a high catalytic activity for benzyl alcohol oxidation.

  10. Excess surface area in bioelectrochemical systems causes ion transport limitations.

    PubMed

    Harrington, Timothy D; Babauta, Jerome T; Davenport, Emily K; Renslow, Ryan S; Beyenal, Haluk

    2015-05-01

    We investigated ion transport limitations on 3D graphite felt electrodes by growing Geobacter sulfurreducens biofilms with advection to eliminate external mass transfer limitations. We characterized ion transport limitations by: (i) showing that serially increasing NaCl concentration up to 200 mM increased current linearly up to a total of +273% vs. 0 mM NaCl under advective conditions; (ii) growing the biofilm with a starting concentration of 200 mM NaCl, which led to a maximum current increase of 400% vs. current generation without NaCl, and (iii) showing that un-colonized surface area remained even after steady-state current was reached. After accounting for iR effects, we confirmed that the excess surface area existed despite a non-zero overpotential. The fact that the biofilm was constrained from colonizing and producing further current under these conditions confirmed the biofilms under study here were ion transport-limited. Our work demonstrates that the use of high surface area electrodes may not increase current density when the system design allows ion transport limitations to become dominant.

  11. Facile synthesis of high surface area molybdenum nitride and carbide

    SciTech Connect

    Roy, Aaron; Serov, Alexey; Artyushkova, Kateryna; Brosha, Eric L.; Atanassov, Plamen; Ward, Tim L.

    2015-08-15

    The synthesis of high surface area γ-Mo{sub 2}N and α-Mo{sub 2}C is reported (116 and 120 m{sup 2}/g) without the temperature programmed reduction of MoO{sub 3}. γ-Mo{sub 2}N was prepared in an NH{sub 3}-free synthesis using forming gas (7 at% H{sub 2}, N{sub 2}-balance) as the reactive atmosphere. Three precursors were studied ((NH{sub 4}){sub 6}Mo{sub 7}O{sub 24}·4H{sub 2}O, (NH{sub 4}){sub 2} Mg(MoO{sub 4}){sub 2}, and MgMoO{sub 4}) along with the sacrificial support method (SSM) as a means of reducing the particle size of Mo{sub 2}N and Mo{sub 2}C. In situ X-ray diffraction (XRD) studies were carried out to identify reaction intermediates, the temperature at which various intermediates form, and the average domain size of the Mo{sub 2}N products. Materials were synthesized in bulk and further characterized by XRD, HRTEM, XPS, and BET. - Highlights: • Facile synthesis of γ-Mo2N and α-Mo2C with surface area exceeding 100 m{sup 2}/g. • Sacrificial support method was used to achieve these high surface areas. • Materials can serve as catalysts or supports in (electro)chemical processes.

  12. Determination of Glacier Surface Area Using Spaceborne SAR Imagery

    NASA Astrophysics Data System (ADS)

    Fang, L.; Maksymiuk, O.; Schmitt, M.; Stilla, U.

    2013-04-01

    Glaciers are very important climate indicators. Although visible remote sensing techniques can be used to extract glacier variations effectively and accurately, the necessary data are depending on good weather conditions. In this paper, a method for determination of glacier surface area using multi-temporal and multi-angle high resolution TerraSAR-X data sets is presented. We reduce the "data holes" in the SAR scenes affected by radar shadowing and specular backscattering of smooth ice surfaces by combining the two complementary different imaging geometries (from ascending and descending satellite tracks). Then, a set of suitable features is derived from the intensity image, the texture information generated based on the gray level co-occurrence matrix (GLCM), glacier velocity estimated by speckle tracking, and the interferometric coherence map. Furthermore, the features are selected by 10-foldcross- validation based on the feature relevance importance on classification accuracy using a Random Forests (RF) classifier. With these most relevant features, the glacier surface is discriminated from the background by RF classification in order to calculate the corresponding surface area.

  13. Recombinant interferon alpha 2b for ocular surface squamous neoplasia: An efficient and cost-effective treatment modality in Asian Indian patients

    PubMed Central

    Kaliki, Swathi; Singh, Swati; Iram, Sadiya; Tripuraneni, Dharani

    2016-01-01

    Purpose: The purpose was to study the efficacy of interferon alpha 2b (INF α2b) in the treatment of ocular surface squamous neoplasia (OSSN) and analyze its cost-effectiveness in India. Study Design: This was a retrospective study of thirty patients with OSSN treated with topical INF α2b (1 MIU/cc) ± perilesional INF α2b (5 MIU/cc). Results: The tumor involved cornea (n = 9, 30%), conjunctivo-limbal-corneal surface (n = 19, 63%), or bulbar conjunctiva (n = 2, 7%). The mean basal dimension of the tumor was 16 mm. The tumors belonged to Tis (n = 6, 20%) or T3 (n = 24, 80%) based on the American Joint Committee Classification, 7th edition. In the six patients with Tis, three cycles of topical INF α2b were used for immunoprevention. In the remaining 24 patients, INF α2b was advised for immunoreduction, but served as immunotherapy with 100% tumor regression in 22 (92%) cases, and resulted in 95% immunoreduction in 2 (6%) cases. Complete tumor regression by immunotherapy (n = 22) was achieved with a mean number of three topical INF α2b cycles and two perilesional injections. All these 22 patients received three additional topical INF α2b cycles after complete tumor regression. For immunoreduction (n = 2), both patients received six cycles of topical INF α2b which was three perilesional INF α2b injections. The mean total treatment cost per patient with INF α2b was INR 9164 ($US 137). Based on maximum basal diameter of tumor at presentation, the mean total treatment cost per patient with INF α2b was INR 4866 ($US 73) for eyes with microscopic evidence of tumor residue (n = 6), INR 9607 ($US 143) for tumors ≤10 mm (n = 13), and INR 10,985 ($US 164) for tumors >10 mm (n = 11), with two patients needing additional surgical excision for complete tumor control. Conclusion: INF α2b can be used for immunoreduction, immunotherapy, or immunoprevention of OSSN. INF α2b is a cost-effective treatment modality for OSSN at an average total treatment cost of INR 9164 ($US

  14. Estimation of surface runoff and water-covered area during filling of surface microrelief depressions

    NASA Astrophysics Data System (ADS)

    Hansen, B.

    2000-05-01

    During the filling of surface microrelief depressions the precipitation excess (precipitation minus infiltration and interception) is divided between surface storage and runoff, i.e. runoff starts before the surface depressions are filled. Information on the division of precipitation excess is needed for modelling surface runoff during the filling of surface depressions. Furthermore, information on the surface of the area covered with water is needed for calculating infiltration of water stored in soil surface depressions. Thirty-two soil surface microreliefs were determined in Danish erosion study plots. The slope was c. 10% for all plots. Data were treated initially by removing the slope, after which 20 artificial slopes (1-20%) were introduced producing 640 new data sets. Runoff during filling of the microrelief storage was calculated for each of the 640 data sets using a model developed for calculating surface storage and runoff from grid elevation measurements. Runoff started immediately after the first addition of water for all data sets. On a field scale, however, runoff has to travel some distance as overland flow and storage in smaller and larger depressions below the runoff initiation point must be taken into consideration. The runoff increases by intermittent steps. Whenever a depression starts to overflow to the border of the plot, the runoff jumps accordingly. In spite of the jumps, the distribution between surface storage and runoff was closely related to the quotient between precipitation excess and depression storage capacity. Surface area covered with water was exponentially related to the amount of water stored in surface depressions. Models for calculating surface storage and runoff from grid elevation measurements are cumbersome and require time-consuming measurements of the soil surface microrelief. Therefore, estimation from roughness indices requiring fewer measurements is desirable. New improved equations for such estimations are suggested.

  15. Cornea and ocular surface treatment.

    PubMed

    De Miguel, Maria P; Alio, Jorge L; Arnalich-Montiel, Francisco; Fuentes-Julian, Sherezade; de Benito-Llopis, Laura; Amparo, Francisco; Bataille, Laurent

    2010-06-01

    In addition to being a protective shield, the cornea represents two thirds of the eye's refractive power. Corneal pathology can affect one or all of the corneal layers, producing corneal opacity. Although full corneal thickness keratoplasty has been the standard procedure, the ideal strategy would be to replace only the damaged layer. Current difficulties in corneal transplantation, mainly immune rejection and shortage of organ supply, place more emphasis on the development of artificial corneas. Bioengineered corneas range from prosthetic devices that solely address the replacement of the corneal function, to tissue-engineered hydrogels that allow regeneration of the tissue. Recently, major advances in the biology of corneal stem cells have been achieved. However, the therapeutic use of these stem cell types has the disadvantage of needing an intact stem cell compartment, which is usually damaged. In addition, long ex vivo culture is needed to generate enough cell numbers for transplantation. In the near future, combination of advanced biomaterials with cells from abundant outer sources will allow advances in the field. For the former, magnetically aligned collagen is one of the most promising ones. For the latter, different cell types will be optimal: 1) for epithelial replacement: oral mucosal epithelium, ear epidermis, or bone marrow- mesenchymal stem cells, 2) for stromal regeneration: adipose-derived stem cells and 3) for endothelial replacement, the possibility of in vitro directed differentiation of adipose-derived stem cells towards endothelial cells provides an exciting new approach.

  16. High surface area aerogels for energy storage and efficiency

    NASA Astrophysics Data System (ADS)

    Maloney, Ryan Patrick

    ADAI are demonstrated in a third-generation prototypical thermoelectric generator for automotive waste heat recovery. The second chapter then details two different aerogel-based materials for electrochemical energy storage. It begins with lithium titanate aerogel, which takes advantage of the high surface area of the aerogel morphology to display a batt-cap behavior. This should allow the lithium titanate aerogel to perform at higher rates than would normally be expected for the bulk oxide material. Additionally, the flexibility of the sol-gel process is demonstrated through the incorporation of electrically conductive high-surface area exfoliated graphite nanoplatelets in the oxide. The last section describes the characterization of a LiMn2O 4 spinel coated carbon nanofoam in a non-aqueous electrolyte. The short diffusion path, high surface area and intimately wired architecture of the nanofoam allows the oxide to retain its capacity at significantly higher rates when compared with literature values for the bulk oxide. Additionally, the nanometric length scale improves cycle life, and the high surface area dramatically increases the insertion capacity by providing a higher concentration of surface defects. Taken together, it is clear that aerogels are an extremely attractive class of material for applications pertaining to energy and efficiency, and further research in this area will provide valuable solutions for pressing societal needs. (Abstract shortened by UMI.).

  17. [Three-dimension reconstruction of ocular fundus image].

    PubMed

    Chen, Ji; Peng, Chenglin

    2008-02-01

    The mathematical model for 3D reconstruction of ocular fundus images is constructed according to both the reduced eye model and the simplified model of fundus camera optical system. The relationship between the images of emmetropic and ametropic eye and the true shape of ocular fundus retina is analyzed, and then the mapping relationship from 2D ocular fundus plan image to 3D surface image is obtained. As a result, the real example of 3D reconstruction for ocular fundus images is given. The max visual field of ocular fundus image for three-dimensional reconstruction is decided by the max visual field angle of fundus camera, which limits a size of the visual field of 3D reconstruction image and a range of z axis. According to the formulas of 3D mapping, the 2D data of ocular fundus image is mapped to 3D data and then veins mapping is carried out; thereafter, the 3D surface image of ocular fundus can be drawn immediately. This method makes use of the existing 2D imaging equipments to provide 3D surface image of patient's ocular fundus, and can provide ophthalmologist with beneficial reference and help to their clinical diagnosis and treatment.

  18. Microemulsion: New Insights into the Ocular Drug Delivery

    PubMed Central

    Hegde, Rahul Rama; Verma, Anurag; Ghosh, Amitava

    2013-01-01

    Delivery of drugs into eyes using conventional drug delivery systems, such as solutions, is a considerable challenge to the treatment of ocular diseases. Drug loss from the ocular surface by lachrymal fluid secretion, lachrymal fluid-eye barriers, and blood-ocular barriers are main obstacles. A number of ophthalmic drug delivery carriers have been made to improve the bioavailability and to prolong the residence time of drugs applied topically onto the eye. The potential use of microemulsions as an ocular drug delivery carrier offers several favorable pharmaceutical and biopharmaceutical properties such as their excellent thermodynamic stability, phase transition to liquid-crystal state, very low surface tension, and small droplet size, which may result in improved ocular drug retention, extended duration of action, high ocular absorption, and permeation of loaded drugs. Further, both lipophilic and hydrophilic characteristics are present in microemulsions, so that the loaded drugs can diffuse passively as well get significantly partitioned in the variable lipophilic-hydrophilic corneal barrier. This review will provide an insight into previous studies on microemulsions for ocular delivery of drugs using various nonionic surfactants, cosurfactants, and associated irritation potential on the ocular surface. The reported in vivo experiments have shown a delayed effect of drug incorporated in microemulsion and an increase in the corneal permeation of the drug. PMID:23936681

  19. Surface area-dependent second harmonic generation from silver nanorods.

    PubMed

    Ngo, Hoang Minh; Luong, Thanh Tuyen; Ledoux-Rak, Isabelle

    2016-08-17

    The nonlinear optical (NLO) properties of metallic nanoparticles strongly depend on their size and shape. Metallic gold nanorods have already been widely investigated, but other noble metals could also be used for nanorod fabrication towards applications in photonics. Here we report on the synthesis and NLO characterization of silver nanorods (AgNRs) with controllable localized surface plasmon resonance. We have implemented an original, one-step and seedless synthesis method, based on a spontaneous particle growth technique in the presence of polyvinylpyrrolidone (PVP) as a capping agent. Colloidal solutions of AgNRs with various aspect ratios (5.0; 6.3; 7.5; 8.2 and 9.7) have been obtained and characterized using Harmonic light scattering (HLS) at 1064 nm, in order to investigate their quadratic NLO properties. From HLS experiments, we demonstrate that hyperpolarizability (β) values of AgNRs display a strong dependence on their surface area.

  20. Fabrication of large area nanostructures with surface modified silica spheres

    NASA Astrophysics Data System (ADS)

    Kang, Kwang-Sun

    2014-03-01

    Surface modification of silica spheres with 3-(trimethoxysilyl)propylmethacrylate (TMSPM) has been performed at ambient condition. However, the FTIR spectra and field emission scanning electron microscope (FESEM) images show no evidence of the surface modification. The reaction temperatures were varied from 60 to 80 °C with various reaction periods. Small absorption shoulder of the CO stretching vibration was at 1700 cm-1, and slightly increased with the increase of the reaction time at 60 °C. The clear absorption peak appeared at 1698 cm-1 for the spheres reacted for 80 min at 70 °C and shifted toward 1720 cm-1 with the increase the reaction time. Strong absorption peak showed at 1698 cm-1 and shifted toward 1725 cm-1 with the increase of the reaction time at 80 °C. The spheres were dispersed to methanol and added photoinitiator (Irgacure-184). The solution was poured to a patterned glass substrate and exposed to the 254 nm UV-light during a self-assembly process. A large area and crack-free silica sphere film was formed. To increase the mechanical stability, a cellulose acetate solution was spin-coated to the film. The film was lift-off from the glass substrate to analyze the surface nanostructures. The surface nanostructures were maintained, and the film is stable enough to use as a mold to duplicate the nanopattern and flexible.

  1. Ocular manifestations of xeroderma pigmentosum: long term follow-up highlights the role of DNA repair in protection from sun damage

    PubMed Central

    Brooks, Brian P; Thompson, Amy H; Bishop, Rachel J; Clayton, Janine A; Chan, Chi-Chao; Tsilou, Ekaterini T; Zein, Wadih M; Tamura, Deborah; Khan, Sikandar G.; Ueda, Takahiro; Boyle, Jennifer; Oh, Kyu-Seon; Imoto, Kyoko; Inui, Hiroki; Moriwaki, Shin-Ichi; Emmert, Steffen; Iliff, Nicholas T.; Bradford, Porcia; DiGiovanna, John J.; Kraemer, Kenneth H

    2013-01-01

    Objective Xeroderma pigmentosum (XP) is a rare autosomal recessive disease caused by mutations in DNA repair genes. Clinical manifestations of XP include mild to extreme sensitivity to ultraviolet radiation resulting in inflammation and neoplasia in sun-exposed areas of the skin, mucous membranes, and ocular surfaces. This report describes the ocular manifestations of XP in patients systematically evaluated in the Clinical Center at the National Institutes of Health. Design Retrospective Observational Case Series Participants Eighty-seven participants, aged 1.3 to 63.4 years, referred to the National Eye Institute for examination from 1964 to 2011. Eighty-three had XP, 3 had XP/Cockayne Syndrome complex, and 1 had XP/trichothiodystrophy complex. Methods Complete, age- and developmental stage-appropriate ophthalmic examination. Main Outcome Measures Visual acuity; eyelid, ocular surface and lens pathology; tear film and tear production measures; and cytological analysis of conjunctival surface swabs. Results Of the 87 patients, 91% had at least one ocular abnormality. The most common abnormalities were conjunctivitis (51%), corneal neovascularization (44%), dry eye (38%), corneal scarring (26%), ectropion (25%), blepharitis (23%), conjunctival melanosis (20%), and cataracts (14%). Thirteen percent of patients had some degree of visual axis impingement and 5% had no light perception in one or both eyes. Ocular surface cancer or a history of ocular surface cancer was present in 10% of patients. Patients with an acute sunburning skin phenotype were less likely to develop conjunctival melanosis and ectropion but more likely to develop neoplastic ocular surface lesions than non-burning patients. Some patients also showed signs of limbal stem cell deficiency. Conclusions Our longitudinal study reports the ocular status of the largest group of XP patients systematically examined at one facility over an extended period of time. Structural eyelid abnormalities, neoplasms of

  2. Thermodynamic surface system of static black holes and area law

    NASA Astrophysics Data System (ADS)

    Chen, Ming; Huang, Yong-Chang

    2016-11-01

    We propose a new picture of black holes through a special holographic screen. This holographic screen contains all the degrees of freedom of a black hole. We find that this holographic screen is similar to the ordinary thermodynamic surface system. Meanwhile, through the “white-wall box” and the formula of sound velocity, we find some similarities between gravitons and photons. We further assume that such a holographic screen is a kind of Bose-Einstein condensate of gravitons. Through this assumption and those similarities, we finally get the area law of static black holes. Supported by National Natural Science Foundation of China (11275017, 11173028)

  3. Hydroetching of high surface area ceramics using moist supercritical fluids

    DOEpatents

    Fryxell, Glen; Zemanian, Thomas S.

    2004-11-02

    Aerogels having a high density of hydroxyl groups and a more uniform pore size with fewer bottlenecks are described. The aerogel is exposed to a mixture of a supercritical fluid and water, whereupon the aerogel forms a high density of hydroxyl groups. The process also relaxes the aerogel into a more open uniform internal structure, in a process referred to as hydroetching. The hydroetching process removes bottlenecks from the aerogels, and forms the hydrogels into more standard pore sizes while preserving their high surface area.

  4. High surface area graphene-supported metal chalcogenide assembly

    DOEpatents

    Worsley, Marcus A.; Kuntz, Joshua; Orme, Christine A.

    2016-04-19

    A composition comprising at least one graphene-supported assembly, which comprises a three-dimensional network of graphene sheets crosslinked by covalent carbon bonds, and at least one metal chalcogenide compound disposed on said graphene sheets, wherein the chalcogen of said metal chalcogenide compound is selected from S, Se and Te. Also disclosed are methods for making and using the graphene-supported assembly, including graphene-supported MoS.sub.2. Monoliths with high surface area and conductivity can be achieved. Lower operating temperatures in some applications can be achieved. Pore size and volume can be tuned.

  5. Metal-organic framework materials with ultrahigh surface areas

    DOEpatents

    Farha, Omar K.; Hupp, Joseph T.; Wilmer, Christopher E.; Eryazici, Ibrahim; Snurr, Randall Q.; Gomez-Gualdron, Diego A.; Borah, Bhaskarjyoti

    2015-12-22

    A metal organic framework (MOF) material including a Brunauer-Emmett-Teller (BET) surface area greater than 7,010 m.sup.2/g. Also a metal organic framework (MOF) material including hexa-carboxylated linkers including alkyne bond. Also a metal organic framework (MOF) material including three types of cuboctahedron cages fused to provide continuous channels. Also a method of making a metal organic framework (MOF) material including saponifying hexaester precursors having alkyne bonds to form a plurality of hexa-carboxylated linkers including alkyne bonds and performing a solvothermal reaction with the plurality of hexa-carboxylated linkers and one or more metal containing compounds to form the MOF material.

  6. Urban areas impact on surface water quality during rainfall events

    NASA Astrophysics Data System (ADS)

    Ferreira, C. S. S.; Soares, D.; Ferreira, A. J. D.; Costa, M. L.; Steenhuis, T. S.; Coelho, C. O. A.; Walsh, R. P. D.

    2012-04-01

    Increasing population and welfare puts water management under stress, especially in what concerns water quality. Surface water properties are strongly linked with hydrological processes and are affected by stream flow variability. Changes in some chemical substances concentrations can be ascribed to different water sources. Runoff generated in urban areas is considered the main responsible for water quality degradation inside catchments. This poster presents the methodology and first results of a study that is being developed to assess the impact of urbanization on surface water quality, during rainfall events. It focuses on the Ribeira dos Covões catchment (620 ha) located in central Portugal. Due to its proximity to the Coimbra city in central region, the urban areas sprawled during the last decades. In 2008, urban areas represented 32% of the area. Recently a highway was constructed crossing the catchment and a technological industrial park is being build-up in the headwaters. Several water samples were collected at four different locations: the catchment outlet and in three sub-catchments with distinct urbanization patterns - Espírito Santo that represents a highly urbanized area (45%) located over sandstone, Porto do Bordalo with 30% of urbanized area located over limestone, and IParque, mainly forest and just downstream the disturbed technological industrial park construction area. The samples were collected at different times during rainfall events to monitor the variability along the hydrograph. Six monitoring campaigns were performed: two in April 2011, at the end of the winter period, and the others between October and November 2011, after the dry summer. The number of samples collected per monitoring campaign is variable according with rainfall pattern. Parameters such as pH, conductivity, turbidity and total suspended sediments were immediately analyzed. The samples were then preserved, after filtered (0.45µm), and later analyzed for dissolved

  7. Nitridation under ammonia of high surface area vanadium aerogels

    SciTech Connect

    Merdrignac-Conanec, Odile . E-mail: odile.merdrignac@univ-rennes1.fr; El Badraoui, Khadija; L'Haridon, Paul

    2005-01-15

    Vanadium pentoxide gels have been obtained from decavanadic acid prepared by ion exchange on a resin from ammonium metavanadate solution. The progressive removal of water by solvent exchange in supercritical conditions led to the formation of high surface area V{sub 2}O{sub 5}, 1.6H{sub 2}O aerogels. Heat treatment under ammonia has been performed on these aerogels in the 450-900 deg. C temperature range. The oxide precursors and oxynitrides have been characterized by XRD, SEM, TGA, BET. Nitridation leads to divided oxynitride powders in which the fibrous structure of the aerogel is maintained. The use of both very low heating rates and high surface area aerogel precursors allows a higher rate and a lower threshold of nitridation than those reported in previous works. By adjusting the nitridation temperature, it has been possible to prepare oxynitrides with various nitrogen enrichment and vanadium valency states. Whatever the V(O,N) composition, the oxidation of the oxynitrides in air starts between 250 and 300 deg. C. This determines their potential use as chemical gas sensors at a maximum working temperature of 250 deg. C.

  8. High surface area, low weight composite nickel fiber electrodes

    NASA Technical Reports Server (NTRS)

    Johnson, Bradley A.; Ferro, Richard E.; Swain, Greg M.; Tatarchuk, Bruce J.

    1993-01-01

    The energy density and power density of light weight aerospace batteries utilizing the nickel oxide electrode are often limited by the microstructures of both the collector and the resulting active deposit in/on the collector. Heretofore, these two microstructures were intimately linked to one another by the materials used to prepare the collector grid as well as the methods and conditions used to deposit the active material. Significant weight and performance advantages were demonstrated by Britton and Reid at NASA-LeRC using FIBREX nickel mats of ca. 28-32 microns diameter. Work in our laboratory investigated the potential performance advantages offered by nickel fiber composite electrodes containing a mixture of fibers as small as 2 microns diameter (Available from Memtec America Corporation). These electrode collectors possess in excess of an order of magnitude more surface area per gram of collector than FIBREX nickel. The increase in surface area of the collector roughly translates into an order of magnitude thinner layer of active material. Performance data and advantages of these thin layer structures are presented. Attributes and limitations of their electrode microstructure to independently control void volume, pore structure of the Ni(OH)2 deposition, and resulting electrical properties are discussed.

  9. Nanosilver on nanostructured silica: Antibacterial activity and Ag surface area

    PubMed Central

    Sotiriou, Georgios A.; Teleki, Alexandra; Camenzind, Adrian; Krumeich, Frank; Meyer, Andreas; Panke, Sven; Pratsinis, Sotiris E.

    2013-01-01

    Nanosilver is one of the first nanomaterials to be closely monitored by regulatory agencies worldwide motivating research to better understand the relationship between Ag characteristics and antibacterial activity. Nanosilver immobilized on nanostructured silica facilitates such investigations as the SiO2 support hinders the growth of nanosilver during its synthesis and, most importantly, its flocculation in bacterial suspensions. Here, such composite Ag/silica nanoparticles were made by flame spray pyrolysis of appropriate solutions of Ag-acetate or Ag-nitrate and hexamethyldisiloxane or tetraethylorthosilicate in ethanol, propanol, diethylene glucolmonobutyl ether, acetonitrile or ethylhexanoic acid. The effect of solution composition on nanosilver characteristics and antibacterial activity against the Gram negative Escherichia coli was investigated by monitoring their recombinantly synthesized green fluorescent protein. Suspensions with identical Ag mass concentration exhibited drastically different antibacterial activity pointing out that the nanosilver surface area concentration rather than its mass or molar or number concentration determine best its antibacterial activity. Nanosilver made from Ag-acetate showed a unimodal size distribution, while that made from inexpensive Ag-nitrate exhibited a bimodal one. Regardless of precursor composition or nanosilver size distribution, the antibacterial activity of nanosilver was correlated best with its surface area concentration in solution. PMID:23730198

  10. High surface area graphene foams by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Drieschner, Simon; Weber, Michael; Wohlketzetter, Jörg; Vieten, Josua; Makrygiannis, Evangelos; Blaschke, Benno M.; Morandi, Vittorio; Colombo, Luigi; Bonaccorso, Francesco; Garrido, Jose A.

    2016-12-01

    Three-dimensional (3D) graphene-based structures combine the unique physical properties of graphene with the opportunity to get high electrochemically available surface area per unit of geometric surface area. Several preparation techniques have been reported to fabricate 3D graphene-based macroscopic structures for energy storage applications such as supercapacitors. Although reaserch has been focused so far on achieving either high specific capacitance or high volumetric capacitance, much less attention has been dedicated to obtain high specific and high volumetric capacitance simultaneously. Here, we present a facile technique to fabricate graphene foams (GF) of high crystal quality with tunable pore size grown by chemical vapor deposition. We exploited porous sacrificial templates prepared by sintering nickel and copper metal powders. Tuning the particle size of the metal powders and the growth temperature allow fine control of the resulting pore size of the 3D graphene-based structures smaller than 1 μm. The as-produced 3D graphene structures provide a high volumetric electric double layer capacitance (165 mF cm-3). High specific capacitance (100 Fg-1) is obtained by lowering the number of layers down to single layer graphene. Furthermore, the small pore size increases the stability of these GFs in contrast to the ones that have been grown so far on commercial metal foams. Electrodes based on the as-prepared GFs can be a boost for the development of supercapacitors, where both low volume and mass are required.

  11. Nanosilver on nanostructured silica: Antibacterial activity and Ag surface area.

    PubMed

    Sotiriou, Georgios A; Teleki, Alexandra; Camenzind, Adrian; Krumeich, Frank; Meyer, Andreas; Panke, Sven; Pratsinis, Sotiris E

    2011-06-01

    Nanosilver is one of the first nanomaterials to be closely monitored by regulatory agencies worldwide motivating research to better understand the relationship between Ag characteristics and antibacterial activity. Nanosilver immobilized on nanostructured silica facilitates such investigations as the SiO2 support hinders the growth of nanosilver during its synthesis and, most importantly, its flocculation in bacterial suspensions. Here, such composite Ag/silica nanoparticles were made by flame spray pyrolysis of appropriate solutions of Ag-acetate or Ag-nitrate and hexamethyldisiloxane or tetraethylorthosilicate in ethanol, propanol, diethylene glucolmonobutyl ether, acetonitrile or ethylhexanoic acid. The effect of solution composition on nanosilver characteristics and antibacterial activity against the Gram negative Escherichia coli was investigated by monitoring their recombinantly synthesized green fluorescent protein. Suspensions with identical Ag mass concentration exhibited drastically different antibacterial activity pointing out that the nanosilver surface area concentration rather than its mass or molar or number concentration determine best its antibacterial activity. Nanosilver made from Ag-acetate showed a unimodal size distribution, while that made from inexpensive Ag-nitrate exhibited a bimodal one. Regardless of precursor composition or nanosilver size distribution, the antibacterial activity of nanosilver was correlated best with its surface area concentration in solution.

  12. Investigation of Sea Surface Temperature (SST) anomalies over Cyprus area

    NASA Astrophysics Data System (ADS)

    Georgiou, Andreas; Akçit, Nuhcan

    2016-08-01

    The temperature of the sea surface has been identified as an important parameter of the natural environment, governing processes that occur in the upper ocean. This paper focuses on the analysis of the Sea Surface Temperature (SST) anomalies at the greater area of Cyprus. For that, SST data derived from MODerate-resolution Imaging Spectroradiometer (MODIS) instrument on board both Aqua and Terra sun synchronous satellites were used. A four year period was chosen as a first approach to address and describe this phenomenon. Geographical Information Systems (GIS) has been used as an integrated platform of analysis and presentation in addition of the support of MATLAB®. The methodology consists of five steps: (i) Collection of MODIS SST imagery, (ii) Development of the digital geo-database; (iii) Model and run the methodology in GIS as a script; (iv) Calculation of SST anomalies; and (v) Visualization of the results. The SST anomaly values have presented a symmetric distribution over the study area with an increase trend through the years of analysis. The calculated monthly and annual average SST anomalies (ASST) make more obvious this trend, with negative and positive SST changes to be distributed over the study area. In terms of seasons, the same increase trend presented during spring, summer, autumn and winter with 2013 to be the year with maximum ASST observed values. Innovative aspects comprise of straightforward integration and modeling of available tools, providing a versatile platform of analysis and semi-automation of the operation. In addition, the fine resolution maps that extracted from the analysis with a wide spatial coverage, allows the detail representation of SST and ASST respectively in the region.

  13. Surface States and Effective Surface Area on Photoluminescent P-Type Porous Silicon

    NASA Technical Reports Server (NTRS)

    Weisz, S. Z.; Porras, A. Ramirez; Resto, O.; Goldstein, Y.; Many, A.; Savir, E.

    1997-01-01

    The present study is motivated by the possibility of utilizing porous silicon for spectral sensors. Pulse measurements on the porous-Si/electrolyte system are employed to determine the surface effective area and the surface-state density at various stages of the anodization process used to produce the porous material. Such measurements were combined with studies of the photoluminescence spectra. These spectra were found to shift progressively to the blue as a function of anodization time. The luminescence intensity increases initially with anodization time, reaches a maximum and then decreases with further anodization. The surface state density, on the other hand, increases with anodization time from an initial value of about 2 x 10(exp 12)/sq cm surface to about 1013 sq cm for the anodized surface. This value is attained already after -2 min anodization and upon further anodization remains fairly constant. In parallel, the effective surface area increases by a factor of 10-30. This behavior is markedly different from the one observed previously for n-type porous Si.

  14. Vascular basophilia in ocular and orbital tumors.

    PubMed

    Stowe, G C; Zakov, Z N; Albert, D M; Smith, T R; Sang, D N; Craft, J L

    1979-10-01

    The occurrence of vascular basophilia in ocular tumors has been a selective histologic feature of retinoblastomas. We recently observed a metastatic oat-cell carcinoma to the choroid which also demonstrated such a vascular hematoxyphilia. Histologic review of a variety of ocular and orbital metastatic carcinomas failed to yield a similar basophilic pattern. Examination of 100 consecutive retinoblastomas for vascular basophilia revealed an incidence of 6.0%. Similar material was not seen in any of 125 melanomas, including 10 with areas of necrosis. Histochemical studies showed the basophilic material to be DNA, and electron microscopy revealed the nuclear debris of pyknotic tumor cells to be continuous with identical material surrounding the adjacent blood vessels. The pathogenesis of vascular deposition of DNA in these two ocular tumors remains unclear. This finding most likely represents a form of tumor activity requiring comparatively healthy blood vessels to adequately precipitate liberated nucleic acids being filtered from the necrotic and degenerating tumor tissue.

  15. What Is an Ocular Migraine?

    MedlinePlus

    ... When to seek help What is an ocular migraine? Is it a sign of something serious? Answers ... the other which might have more–serious complications. Migraine aura involving your vision In some cases, ocular ...

  16. Ocular complications of boxing

    PubMed Central

    Bianco, M; Vaiano, A; Colella, F; Coccimiglio, F; Moscetti, M; Palmieri, V; Focosi, F; Zeppilli, P; Vinger, P

    2005-01-01

    Objectives: To investigate the prevalence of ocular injuries in a large population of boxers over a period of 16 years, in particular, the most severe lesions that may be vision threatening. Methods: Clinical records of the medical archive of the Italian Boxing Federation were analysed. A total of 1032 boxers were examined from February 1982 to October 1998. A complete ophthalmological history was available for 956, who formed the study population (a total of 10 697 examinations). The following data were collected: age when started boxing; duration of competitive boxing career (from the date of the first bout); weight category; a thorough ocular history. The following investigations were carried out: measurement of visual acuity and visual fields, anterior segment inspection, applanation tonometry, gonioscopy, and examination of ocular fundus. Eighty age matched healthy subjects, who had never boxed, formed the control group. Results: Of the 956 boxers examined, 428 were amateur (44.8%) and 528 professional (55.2%). The median age at first examination was 23.1 (4.3) years (range 15–36). The prevalence of conjunctival, corneal, lenticular, vitreal, ocular papilla, and retinal alterations in the study population was 40.9% compared with 3.1% in the control group (p⩽0.0001). The prevalence of serious ocular findings (angle, lens, macula, and peripheral retina alterations) was 5.6% in boxers and 3.1% in controls (NS). Conclusions: Boxing does not result in a higher prevalence of severe ocular lesions than in the general population. However, the prevalence of milder lesions (in particular with regard to the conjunctiva and cornea) is noteworthy, justifying the need for adequate ophthalmological surveillance. PMID:15665199

  17. Sodium hydroxide catalyzed monodispersed high surface area silica nanoparticles

    PubMed Central

    Bhakta, Snehasis; Dixit, Chandra K; Bist, Itti; Jalil, Karim Abdel; Suib, Steven L; Rusling, James F

    2016-01-01

    Understanding of the synthesis kinetics and our ability to modulate medium conditions allowed us to generate nanoparticles via an ultra-fast process. The synthesis medium is kept quite simple with tetraethyl orthosilicate (TEOS) as precursor and 50% ethanol and sodium hydroxide catalyst. Synthesis is performed under gentle conditions at 20 °C for 20 min Long synthesis time and catalyst-associated drawbacks are most crucial in silica nanoparticle synthesis. We have addressed both these bottlenecks by replacing the conventional Stober catalyst, ammonium hydroxide, with sodium hydroxide. We have reduced the overall synthesis time from 20 to 1/3 h, ~60-fold decrease, and obtained highly monodispersed nanoparticles with 5-fold higher surface area than Stober particles. We have demonstrated that the developed NPs with ~3-fold higher silane can be used as efficient probes for biosensor applications. PMID:27606068

  18. High surface area ThO/sub 2/ catalyst

    DOEpatents

    Colmenares, C.A.; Somorjai, G.A.; Maj, J.J.

    1983-06-21

    A ThO/sub 2/ catalyst having a high surface area of about 80 to 125m/sup 2//g is synthesized. The compound is synthesized by simultaneously mixing an aqueous solution of ThNO/sub 3/(NO/sub 3/)/sub 4/.4H/sub 2/O with an aqueous solution of Na/sub 2/CO/sub 3/.H/sub 2/O, to produce a solution and solid ThOCO/sub 3/. The solid ThOCO/sub 3/ is separated from the solution, and then calcined at a temperature of about 225 to 300/sup 0/C for about 40 to 55 hours to produce ThO/sub 2/. The ThO/sub 2/ catalyst produced includes Na present as a substitutional cation in an amount equal to about 5 to 10 at. %.

  19. Sodium hydroxide catalyzed monodispersed high surface area silica nanoparticles

    NASA Astrophysics Data System (ADS)

    Bhakta, Snehasis; Dixit, Chandra K.; Bist, Itti; Abdel Jalil, Karim; Suib, Steven L.; Rusling, James F.

    2016-07-01

    Understanding of the synthesis kinetics and our ability to modulate medium conditions allowed us to generate nanoparticles via an ultra-fast process. The synthesis medium is kept quite simple with tetraethyl orthosilicate (TEOS) as precursor and 50% ethanol and sodium hydroxide catalyst. Synthesis is performed under gentle conditions at 20 °C for 20 min Long synthesis time and catalyst-associated drawbacks are most crucial in silica nanoparticle synthesis. We have addressed both these bottlenecks by replacing the conventional Stober catalyst, ammonium hydroxide, with sodium hydroxide. We have reduced the overall synthesis time from 20 to 1/3 h, ∼60-fold decrease, and obtained highly monodispersed nanoparticles with 5-fold higher surface area than Stober particles. We have demonstrated that the developed NPs with ∼3-fold higher silane can be used as efficient probes for biosensor applications.

  20. Method for producing high surface area chromia materials for catalysis

    DOEpatents

    Gash, Alexander E.; Satcher, Joe; Tillotson, Thomas; Hrubesh, Lawrence; Simpson, Randall

    2007-05-01

    Nanostructured chromium(III)-oxide-based materials using sol-gel processing and a synthetic route for producing such materials are disclosed herein. Monolithic aerogels and xerogels having surface areas between 150 m.sup.2/g and 520 m.sup.2/g have been produced. The synthetic method employs the use of stable and inexpensive hydrated-chromium(III) inorganic salts and common solvents such as water, ethanol, methanol, 1-propanol, t-butanol, 2-ethoxy ethanol, and ethylene glycol, DMSO, and dimethyl formamide. The synthesis involves the dissolution of the metal salt in a solvent followed by an addition of a proton scavenger, such as an epoxide, which induces gel formation in a timely manner. Both critical point (supercritical extraction) and atmospheric (low temperature evaporation) drying may be employed to produce monolithic aerogels and xerogels, respectively.

  1. Enhancing pilot situational awareness of the airport surface movement area

    NASA Technical Reports Server (NTRS)

    Jones, D. R.; Young, S. D.

    1994-01-01

    Two studies are being conducted to address airport surface movement area safety and capacity issues by providing enhanced situational awareness information to pilots. One study focuses on obtaining pilot opinion of the Runway Status Light System (RSLS). This system has been designed to reduce the likelihood of runway incursions by informing pilots when a runway is occupied. The second study is a flight demonstration of an rate integrated system consisting of an electronic moving map in the cockpit and display of the aircraft identification to the controller. Taxi route and hold warning information will be sent to the aircraft data link for display on the electronic moving map. This paper describes the plans for the two studies.

  2. Correction of ocular dystopia.

    PubMed

    Janecka, I P

    1996-04-01

    The purpose of this study was to examine results with elective surgical correction of enophthalmos. The study was a retrospective assessment in a university-based referral practice. A consecutive sample of 10 patients who developed ocular dystopia following orbital trauma was examined. The main outcome measures were a subjective evaluation by patients and objective measurements of patients' eye position. The intervention was three-dimensional orbital reconstruction with titanium plates. It is concluded that satisfactory correction of enophthalmos and ocular dystopia can be achieved with elective surgery using titanium plates. In addition, intraoperative measurements of eye position in three planes increases the precision of surgery.

  3. Ocular rosacea: a dermatologic perspective.

    PubMed

    Webster, Guy; Schaller, Martin

    2013-12-01

    As many as 50% of patients given the diagnosis of cutaneous rosacea also have ocular rosacea. Conservative figures indicate that approximately 10 million patients are affected by ocular rosacea in the United States alone. Despite this prevalence, ocular symptoms of rosacea are often improperly diagnosed, particularly when they occur in the absence of skin involvement.

  4. Observations of Nuclear Explosive Melt Glass Textures and Surface Areas

    SciTech Connect

    Kersting, A B; Smith, D K

    2006-01-17

    This memo report summarizes our current knowledge of the appearance of melt glass formed and subsequently deposited in the subsurface after an underground nuclear test. We have collected archived pictures and melt glass samples from a variety of underground nuclear tests that were conducted at the Nevada Test Site (NTS) during the U.S. nuclear testing program. The purpose of our work is to better determine the actual variation in texture and surface area of the melt glass material. This study is motivated by our need to better determine the rate at which the radionuclides incorporated in the melt glass are released into the subsurface under saturated and partially saturated conditions. The rate at which radionuclides are released from the glass is controlled by the dissolution rate of the glass. Glass dissolution, in turn, is a strong function of surface area, glass composition, water temperature and water chemistry (Bourcier, 1994). This work feeds into an ongoing experimental effort to measure the change in surface area of analog glasses as a function of dissolution rate. The conclusions drawn from this study help bound the variation in the textures of analog glass samples needed for the experimental studies. The experimental work is a collaboration between Desert Research Institute (DRI) and Earth and Environmental Sciences-Lawrence Livermore National Laboratory (EES-LLNL). On March 4, 1999 we hosted a meeting at LLNL to present and discuss our findings. The names of the attendees appear at the end of this memo. This memo report further serves to outline and summarize the conclusions drawn from our meeting. The United States detonated over 800 underground nuclear tests at the NTS between 1951 and 1992. In an effort to evaluate the performance of the nuclear tests, drill-back operations were carried out to retrieve samples of rock in the vicinity of the nuclear test. Drill-back samples were sent to Los Alamos National Laboratory (LANL) and Lawrence Livermore

  5. The impact of built-up surfaces on land surface temperatures in Italian urban areas.

    PubMed

    Morabito, Marco; Crisci, Alfonso; Messeri, Alessandro; Orlandini, Simone; Raschi, Antonio; Maracchi, Giampiero; Munafò, Michele

    2016-05-01

    Urban areas are characterized by the very high degree of soil sealing and continuous built-up areas: Italy is one of the European countries with the highest artificial land cover rate, which causes a substantial spatial variation in the land surface temperature (LST), modifying the urban microclimate and contributing to the urban heat island effect. Nevertheless, quantitative data regarding the contribution of different densities of built-up surfaces in determining urban spatial LST changes is currently lacking in Italy. This study, which aimed to provide clear and quantitative city-specific information on annual and seasonal spatial LST modifications resulting from increased urban built-up coverage, was conducted generally throughout the whole year, and specifically in two different periods (cool/cold and warm/hot periods). Four cities (Milan, Rome, Bologna and Florence) were included in the study. The LST layer and the built-up-surface indicator were obtained via use of MODIS remote sensing data products (1km) and a very high-resolution map (5m) of built-up surfaces recently developed by the Italian National Institute for Environmental Protection and Research. The relationships between the dependent (mean daily, daytime and nighttime LST values) and independent (built-up surfaces) variables were investigated through linear regression analyses, and comprehensive built-up-surface-related LST maps were also developed. Statistically significant linear relationships (p<0.001) between built-up surfaces and spatial LST variations were observed in all the cities studied, with a higher impact during the warm/hot period than in the cool/cold ones. Daytime and nighttime LST slope patterns depend on the city size and relative urban morphology. If implemented in the existing city plan, the urban maps of built-up-surface-related LST developed in this study might be able to support more sustainable urban land management practices by identifying the critical areas (Hot

  6. Lung deposited surface area size distributions of particulate matter in different urban areas

    NASA Astrophysics Data System (ADS)

    Kuuluvainen, Heino; Rönkkö, Topi; Järvinen, Anssi; Saari, Sampo; Karjalainen, Panu; Lähde, Tero; Pirjola, Liisa; Niemi, Jarkko V.; Hillamo, Risto; Keskinen, Jorma

    2016-07-01

    Lung deposited surface area (LDSA) concentration is considered as a relevant metric for the negative health effects of aerosol particles. We report for the first time the size distributions of the LDSA measured in urban air. The measurements were carried out in the metropolitan area of Helsinki, including mobile laboratory and stationary measurements in different outdoor environments, such as traffic sites, a park area, the city center and residential areas. The main instrument in this study was an electrical low pressure impactor (ELPI), which was calibrated in the field to measure the LDSA concentration. The calibration factor was determined to be 60 μm2/(cm3 pA). In the experiments, the LDSA size distributions were found to form two modes at the traffic sites and in the city center. Both of these traffic related particle modes, the nucleation mode and the soot mode, had a clear contribution to the total LDSA concentration. The average total concentrations varied from 12 to 94 μm2/cm3, measured in the park area and at the traffic site next to a major road, respectively. The LDSA concentration was found to correlate with the mass of fine particles (PM2.5), but the relation of these two metrics varied between different environments, emphasizing the influence of traffic on the LDSA. The results of this study provide valuable information on the total concentrations and size distributions of the LDSA for epidemiological studies. The size distributions are especially important in estimating the contribution of outdoor concentrations on the concentrations inside buildings and vehicles through size-dependent penetration factors.

  7. Effects of excluded surface area and adsorbate clustering on surface adsorption of proteins. II. Kinetic models.

    PubMed Central

    Minton, A P

    2001-01-01

    Models for equilibrium surface adsorption of proteins have been recently proposed (Minton, A. P., 2000. Biophys. Chem. 86:239-247) in which negative cooperativity due to area exclusion by adsorbate molecules is compensated to a variable extent by the formation of a heterogeneous population of monolayer surface clusters of adsorbed protein molecules. In the present work this concept is extended to treat the kinetics of protein adsorption. It is postulated that clusters may grow via two distinct kinetic pathways. The first pathway is the diffusion of adsorbed monomer to the edge of a preexisting cluster and subsequent accretion. The second pathway consists of direct deposition of a monomer in solution onto the upper (solution-facing) surface of a preexisting cluster ("piggyback" deposition) and subsequent incorporation into the cluster. Results of calculations of the time course of adsorption, carried out for two different limiting models of cluster structure and energetics, show that in the absence of piggyback deposition, enhancement of the tendency of adsorbate to cluster can reduce, but not eliminate, the negative kinetic cooperativity due to surface area exclusion by adsorbate. Apparently noncooperative (Langmuir-like) and positively cooperative adsorption progress curves, qualitatively similar to those reported in several published experimental studies, require a significant fraction of total adsorption flux through the piggyback deposition pathway. According to the model developed here and in the above-mentioned reference, the formation of surface clusters should be a common concomitant of non-site-specific surface adsorption of proteins, and may provide an important mechanism for assembly of organized "protein machines" in vivo. PMID:11259279

  8. [Ocular Manifestations in Sarcoidosis].

    PubMed

    Walscheid, K; Tappeiner, C; Heiligenhaus, A

    2016-05-01

    Sarcoidosis is an inflammatory multi-organ disease of unknown pathogenesis, characterised by non-necrotising granulomata. Sarcoidosis predominantly manifests in the lung, but any other organ may be affected. Ocular involvement is present in about 25 to 50 % of patients. The most common ocular manifestation is uveitis, especially of the anterior eye segment. If ocular sarcoidosis is suspected, interdisciplinary assessment of the patient is mandatory, including laboratory tests, chest X-ray, assessment by a specialist in internal medicine and, ideally, histological evidence of granuloma formation in a tissue specimen. Other (infectious) causes of granulomatous inflammation need to be excluded, especially tuberculosis or syphilis. For the ophthalmological assessment, detection of granulomatous lesions is of particular importance, especially by visualising chorioretinal granuloma by fluorescein and indocyanin green angiography. Cystoid macular oedema and glaucoma are the most frequent complications limiting visual acuity. Corticosteroids, which can be administered either locally or systemically, are the mainstay of therapy. Depending on the clinical course and the development of ocular complications, systemic steroid-sparing immunosuppressive medication may be indicated.

  9. Ocular Screening System

    NASA Technical Reports Server (NTRS)

    1985-01-01

    An ocular screening system designed for safe, convenient screening of large groups was developed at Marshall Space Flight Center, leading to the formation of Medical Sciences Corporation. The system identifies visual defects accurately and inexpensively, and includes a photorefractor telephoto lens and an electronic flash. Medical Sciences Corporation is using the device to test at schools, industrial plants, etc.

  10. Does mineral surface area affect chemical weathering rates?

    NASA Astrophysics Data System (ADS)

    Salome Eiriksdottir, Eydis; Reynir Gislason, Sigurdur; Oelkers, Eric H.

    2010-05-01

    Iceland is a basaltic volcanic island representative of the high relief, volcanic and tectonic active islands that contribute over 45% of river suspended material to the oceans worldwide (Milliman and Syvitski, 1992). These islands have enormous mechanical and chemical weathering rates due to the combined effects of high relief, high runoff, the presence of glaciers and easily weathered volcanic rocks, and a lack of sedimentary traps. In total, Iceland delivers 0.7% of the worldwide river suspended matter flux to the ocean, which is approximately one fourth that of Africa (Tómasson, 1990). River suspended matter from volcanic islands is highly reactive in seawater and might play an important role in the global carbon cycle (Gislason et al., 2006). Thus it is important to define and understand the mechanical and chemical weathering rates of these islands. Experimental dissolution experiments performed in the laboratory suggest that chemical weathering rates should be proportional to rock-water interfacial surface area. This hypothesis is tested in the present study through a study of the chemical composition of suspended material collected from rivers located in Northeast Iceland. These rivers were selected for this study because their catchments essentially monolithic, consisting of uniform compositioned and aged basalts. Gaillardet (1999) described weathering intensities of the worlds river systems to be from 1 (low weathering intensity) to 25 (high weathering intensity). These indexes were calculated to be from 1.8 to 3.2 in rivers in NE-Iceland (Eiriksdottir et al., 2008). The surface area of sediments is inversely proportional to particle size; smaller particles have larger specific surface areas. As a result, smaller particles should weather faster. This trend is confirmed by the measured compositions of analyzed suspended material. The concentration of insoluble elements (Zr, Fe, Cu, Ni, Y) is found to increase in the suspended material, whereas the

  11. Ocular nerve growth factor administration counteracts the impairment of neural precursor cell viability and differentiation in the brain subventricular area of rats with streptozotocin-induced diabetes.

    PubMed

    Tirassa, Paola; Maccarone, Mattia; Carito, Valentina; De Nicolò, Sara; Fiore, Marco

    2015-05-01

    The ocular administration of nerve growth factor (NGF) as eye drops (oNGF) has been shown to exert protective effects in forebrain-injured animal models, including adult diabetes induced by a single injection of streptozotocin (STZ) (60 mg/kg body weight). This type 1 diabetes model was used in this study to investigate whether oNGF might extend its actions on neuronal precursors localised in the subventricular zone (SVZ). NGF or saline was administrated as eye drops twice daily for 2 weeks in rats with STZ-induced diabetes and healthy control rats. The expression of mature and precursor NGF and the NGF receptors, tropomyosin-related kinase A and neurotrophin receptor p75, and the levels of DNA fragmentation were analysed by ELISA and western blotting. Incorporation of bromodeoxyuridine was used to trace newly formed cells. Nestin, polysialylated neuronal cell adhesion molecule (PSA-NCAM), doublecortin (DCX) and glial fibrillary acidic protein antibodies were used to identify the SVZ cells by confocal microscopy. It was found that oNGF counteracts the STZ-induced cell death and the alteration of mature/pro-NGF expression in the SVZ. It also affects the survival and differentiation of SVZ progenitors. In particular, oNGF counteracts the reduction in the number of cells expressing PSA-NCAM/DCX (neuroblast type A cells) and the related reductions in the number and distribution of nestin/DCX-positive cells (C-type cells), or glia-committed cells (type B cells), observed in the SVZ of diabetic rats. These findings show that oNGF treatment counteracts the effect of type 1 diabetes on neuronal precursors in the SVZ, and further support the neuroprotective and reparative role of oNGF in the brain.

  12. Application of a collagen-based membrane and chondroitin sulfate-based hydrogel adhesive for the potential repair of severe ocular surface injuries.

    PubMed

    Chae, Jemin J; Mulreany, Daniel G; Guo, Qiongyu; Lu, Qiaozhi; Choi, Joseph S; Strehin, Iossif; Espinoza, Freddy A; Schein, Oliver; Trexler, Morgana M; Bower, Kraig S; Elisseeff, Jennifer H

    2014-06-01

    This study was performed to evaluate the potential of a chondroitin sulfate-polyethylene glycol (CS-PEG) adhesive and collagen-based membrane (collagen vitrigel, CV) combination as a method to treat penetrating ocular injuries on the battlefield and to improve this method with two technologies: an antibiotic releasing CS-PEG adhesive and a corneal shaped CV. Burst testing using porcine cadaveric eyes, high-performance liquid chromatography, the Kirby-Bauer bacterial inhibition test, and CV implantations on the live and cadaveric rabbit eyes were performed. The ocular burst test showed CS-PEG adhesive could successfully repair 5-mm to 6-mm length wounds in the corneal and corneoscleral regions but would require CS-PEG + CV to treat larger wounds similar to those seen on the battlefield. In addition, high performance liquid chromatography and the Kirby-Bauer bacterial inhibition test presented evidence suggesting the vancomycin incorporated CS-PEG could inhibit Staphylococcus infection for 9 days. Furthermore, the curved CV showed an advantage by matching the corneal contour without any wrinkle formation. Although this pilot study showed a limited range of possible applications, we demonstrated that the combination of CS-PEG adhesive + CV is a promising method and the 2 technologies improve their applicability to the special demands of the battlefield.

  13. Controlled Ocular Drug Delivery with Nanomicelles

    PubMed Central

    Vaishya, Ravi D.; Khurana, Varun; Patel, Sulabh; Mitra, Ashim K.

    2014-01-01

    Many vision threatening ocular diseases such as age-related macular degeneration (AMD), diabetic retinopathy, glaucoma, and proliferative vitreoretinopathy may result in blindness. Ocular drug delivery specifically to the intraocular tissues remains a challenging task due to the presence of various physiological barriers. Nonetheless, recent advancements in the field of nanomicelle based novel drug delivery system could fulfil these unmet needs. Nanomicelles consists of amphiphilic molecules that self-assemble in aqueous media to form organized supramolecular structures. Micelles can be prepared in various sizes (10 to 1000nm) and shapes depending on the molecular weights of the core and corona forming blocks. Nanomicelles have been an attractive carriers for their potential to solubilize hydrophobic molecules in aqueous solution. In addition, small size in nanometer range and highly modifiable surface properties have been reported to be advantageous in ocular drug delivery. In the present review various factors influencing rationale design of nanomicelles formulation and disposition are discussed along with case studies. Despite the progress in the field, influence of various properties of nanomicelles such as size, shape, surface charge, rigidity of structure on ocular disposition need to be studied in further details to develop an efficient nanocarrier system. PMID:24888969

  14. Bicontinuous ceramics with high surface area from block copolymer templates.

    PubMed

    Hsueh, Han-Yu; Ho, Rong-Ming

    2012-06-05

    Mesoporous polymers with gyroid nanochannels can be fabricated from the self-assembly of degradable block copolymer, polystyrene-b-poly(L-lactide) (PS-PLLA), followed by hydrolysis of PLLA block. Well-defined polymer/ceramic nanohybrid materials with inorganic gyroid nanostructures in a PS matrix can be obtained by using the mesoporous PS as a template for sol-gel reaction. Titanium tetraisopropoxide (TTIP) is used as a precursor to give a model system for the fabrication of metal oxide nanostructures from reactive transition metal alkoxides. By controlling the rates of capillary-driven pore filling and sol-gel reaction, the templated synthesis can be well-developed. Also, by taking advantage of calcination, bicontinuous TiO(2) with controlled crystalline phase (i.e., anatase phase) can be fabricated after removal of the PS template and crystallization of TiO(2) by calcination leading to high photocatalytic efficiency. This new approach provides an easy way to fabricate high-surface-area and high-porosity ceramics with self-supporting structure and controlled crystalline phase for practical applications. As a result, a platform technology to fabricate precisely controlled polymer/ceramic nanohybrids and mesoporous ceramic materials can be established.

  15. 30 CFR 905.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... WITHIN EACH STATE CALIFORNIA § 905.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Areas designated unsuitable for surface...

  16. 30 CFR 937.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... WITHIN EACH STATE OREGON § 937.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining and... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Areas designated unsuitable for surface...

  17. 30 CFR 941.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... WITHIN EACH STATE SOUTH DAKOTA § 941.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Areas designated unsuitable for surface...

  18. 30 CFR 921.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... WITHIN EACH STATE MASSACHUSETTS § 921.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Areas designated unsuitable for surface...

  19. 30 CFR 921.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... WITHIN EACH STATE MASSACHUSETTS § 921.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Areas designated unsuitable for surface...

  20. 30 CFR 912.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... WITHIN EACH STATE IDAHO § 912.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining and... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Areas designated unsuitable for surface...

  1. 30 CFR 921.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WITHIN EACH STATE MASSACHUSETTS § 921.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface...

  2. 30 CFR 903.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WITHIN EACH STATE ARIZONA § 903.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, applies to surface coal mining... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface...

  3. 30 CFR 947.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... WITHIN EACH STATE WASHINGTON § 947.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Areas designated unsuitable for surface...

  4. 30 CFR 921.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... WITHIN EACH STATE MASSACHUSETTS § 921.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Areas designated unsuitable for surface...

  5. 30 CFR 947.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... WITHIN EACH STATE WASHINGTON § 947.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Areas designated unsuitable for surface...

  6. 30 CFR 942.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... WITHIN EACH STATE TENNESSEE § 942.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Areas designated unsuitable for surface...

  7. 30 CFR 941.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... WITHIN EACH STATE SOUTH DAKOTA § 941.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Areas designated unsuitable for surface...

  8. 30 CFR 910.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... WITHIN EACH STATE GEORGIA § 910.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Areas designated unsuitable for surface...

  9. 30 CFR 942.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... WITHIN EACH STATE TENNESSEE § 942.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Areas designated unsuitable for surface...

  10. 30 CFR 903.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... WITHIN EACH STATE ARIZONA § 903.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, applies to surface coal mining... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Areas designated unsuitable for surface...

  11. 30 CFR 922.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... WITHIN EACH STATE MICHIGAN § 922.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Areas designated unsuitable for surface...

  12. 30 CFR 910.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... WITHIN EACH STATE GEORGIA § 910.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Areas designated unsuitable for surface...

  13. 30 CFR 905.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... WITHIN EACH STATE CALIFORNIA § 905.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Areas designated unsuitable for surface...

  14. 30 CFR 937.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WITHIN EACH STATE OREGON § 937.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining and... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface...

  15. 30 CFR 912.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WITHIN EACH STATE IDAHO § 912.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining and... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface...

  16. 30 CFR 942.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... WITHIN EACH STATE TENNESSEE § 942.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Areas designated unsuitable for surface...

  17. 30 CFR 947.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WITHIN EACH STATE WASHINGTON § 947.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface...

  18. 30 CFR 921.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... WITHIN EACH STATE MASSACHUSETTS § 921.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Areas designated unsuitable for surface...

  19. 30 CFR 939.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WITHIN EACH STATE RHODE ISLAND § 939.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface...

  20. 30 CFR 903.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... WITHIN EACH STATE ARIZONA § 903.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, applies to surface coal mining... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Areas designated unsuitable for surface...

  1. 30 CFR 942.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... WITHIN EACH STATE TENNESSEE § 942.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Areas designated unsuitable for surface...

  2. 30 CFR 922.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WITHIN EACH STATE MICHIGAN § 922.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface...

  3. 30 CFR 941.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WITHIN EACH STATE SOUTH DAKOTA § 941.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface...

  4. 30 CFR 912.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... WITHIN EACH STATE IDAHO § 912.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining and... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Areas designated unsuitable for surface...

  5. 30 CFR 939.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... WITHIN EACH STATE RHODE ISLAND § 939.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Areas designated unsuitable for surface...

  6. 30 CFR 905.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... WITHIN EACH STATE CALIFORNIA § 905.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Areas designated unsuitable for surface...

  7. 30 CFR 922.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... WITHIN EACH STATE MICHIGAN § 922.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Areas designated unsuitable for surface...

  8. 30 CFR 939.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... WITHIN EACH STATE RHODE ISLAND § 939.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Areas designated unsuitable for surface...

  9. 30 CFR 941.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... WITHIN EACH STATE SOUTH DAKOTA § 941.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Areas designated unsuitable for surface...

  10. 30 CFR 912.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... WITHIN EACH STATE IDAHO § 912.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining and... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Areas designated unsuitable for surface...

  11. 30 CFR 941.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... WITHIN EACH STATE SOUTH DAKOTA § 941.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Areas designated unsuitable for surface...

  12. 30 CFR 937.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... WITHIN EACH STATE OREGON § 937.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining and... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Areas designated unsuitable for surface...

  13. 30 CFR 942.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WITHIN EACH STATE TENNESSEE § 942.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface...

  14. 30 CFR 939.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... WITHIN EACH STATE RHODE ISLAND § 939.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Areas designated unsuitable for surface...

  15. 30 CFR 937.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... WITHIN EACH STATE OREGON § 937.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining and... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Areas designated unsuitable for surface...

  16. 30 CFR 910.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... WITHIN EACH STATE GEORGIA § 910.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Areas designated unsuitable for surface...

  17. 30 CFR 910.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... WITHIN EACH STATE GEORGIA § 910.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Areas designated unsuitable for surface...

  18. 30 CFR 910.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WITHIN EACH STATE GEORGIA § 910.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface...

  19. 30 CFR 937.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... WITHIN EACH STATE OREGON § 937.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining and... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Areas designated unsuitable for surface...

  20. 30 CFR 905.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... WITHIN EACH STATE CALIFORNIA § 905.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Areas designated unsuitable for surface...

  1. 30 CFR 947.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... WITHIN EACH STATE WASHINGTON § 947.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Areas designated unsuitable for surface...

  2. 30 CFR 903.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... WITHIN EACH STATE ARIZONA § 903.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, applies to surface coal mining... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Areas designated unsuitable for surface...

  3. 30 CFR 912.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... WITHIN EACH STATE IDAHO § 912.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining and... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Areas designated unsuitable for surface...

  4. 30 CFR 903.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... WITHIN EACH STATE ARIZONA § 903.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, applies to surface coal mining... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Areas designated unsuitable for surface...

  5. 30 CFR 922.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... WITHIN EACH STATE MICHIGAN § 922.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Areas designated unsuitable for surface...

  6. 30 CFR 947.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... WITHIN EACH STATE WASHINGTON § 947.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Areas designated unsuitable for surface...

  7. 30 CFR 922.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... WITHIN EACH STATE MICHIGAN § 922.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Areas designated unsuitable for surface...

  8. 30 CFR 905.761 - Areas designated unsuitable for surface coal mining by act of Congress.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WITHIN EACH STATE CALIFORNIA § 905.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface...

  9. 30 CFR 939.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... WITHIN EACH STATE RHODE ISLAND § 939.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Areas designated unsuitable for surface...

  10. 30 CFR 903.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for surface coal mining operations. 903.762 Section 903.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE ARIZONA § 903.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  11. 30 CFR 937.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for surface coal mining operations. 937.762 Section 937.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE OREGON § 937.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  12. 30 CFR 922.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for surface coal mining operations. 922.762 Section 922.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE MICHIGAN § 922.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  13. 30 CFR 922.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for surface coal mining operations. 922.762 Section 922.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE MICHIGAN § 922.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  14. 30 CFR 912.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for surface coal mining operations. 912.762 Section 912.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE IDAHO § 912.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  15. 30 CFR 937.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for surface coal mining operations. 937.762 Section 937.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE OREGON § 937.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  16. 30 CFR 922.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for surface coal mining operations. 922.762 Section 922.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE MICHIGAN § 922.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  17. 30 CFR 910.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for surface coal mining operations. 910.762 Section 910.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE GEORGIA § 910.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  18. 30 CFR 912.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for surface coal mining operations. 912.762 Section 912.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE IDAHO § 912.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  19. 30 CFR 910.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for surface coal mining operations. 910.762 Section 910.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE GEORGIA § 910.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  20. 30 CFR 922.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for surface coal mining operations. 922.762 Section 922.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE MICHIGAN § 922.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  1. 30 CFR 912.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for surface coal mining operations. 912.762 Section 912.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE IDAHO § 912.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  2. 30 CFR 910.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for surface coal mining operations. 910.762 Section 910.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE GEORGIA § 910.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  3. 30 CFR 903.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for surface coal mining operations. 903.762 Section 903.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE ARIZONA § 903.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  4. 30 CFR 903.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for surface coal mining operations. 903.762 Section 903.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE ARIZONA § 903.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  5. 30 CFR 922.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for surface coal mining operations. 922.762 Section 922.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE MICHIGAN § 922.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  6. 30 CFR 937.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for surface coal mining operations. 937.762 Section 937.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE OREGON § 937.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  7. 30 CFR 910.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for surface coal mining operations. 910.762 Section 910.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE GEORGIA § 910.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  8. 30 CFR 912.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for surface coal mining operations. 912.762 Section 912.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE IDAHO § 912.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  9. 30 CFR 937.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for surface coal mining operations. 937.762 Section 937.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE OREGON § 937.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  10. 30 CFR 903.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for surface coal mining operations. 903.762 Section 903.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE ARIZONA § 903.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  11. 30 CFR 937.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for surface coal mining operations. 937.762 Section 937.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE OREGON § 937.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  12. 30 CFR 912.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for surface coal mining operations. 912.762 Section 912.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE IDAHO § 912.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  13. 30 CFR 903.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for surface coal mining operations. 903.762 Section 903.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE ARIZONA § 903.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  14. 30 CFR 910.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for surface coal mining operations. 910.762 Section 910.762 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE GEORGIA § 910.762 Criteria for designating areas as unsuitable for surface coal mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal...

  15. 30 CFR 910.764 - Process for designating areas unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... surface coal mining operations. 910.764 Section 910.764 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE GEORGIA § 910.764 Process for designating areas unsuitable for surface coal mining operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface...

  16. 30 CFR 903.764 - Process for designating areas unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... surface coal mining operations. 903.764 Section 903.764 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE ARIZONA § 903.764 Process for designating areas unsuitable for surface coal mining operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface...

  17. 30 CFR 905.764 - Process for designating areas unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... surface coal mining operations. 905.764 Section 905.764 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE CALIFORNIA § 905.764 Process for designating areas unsuitable for surface coal mining operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface...

  18. 30 CFR 912.764 - Process for designating areas unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... surface coal mining operations. 912.764 Section 912.764 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE IDAHO § 912.764 Process for designating areas unsuitable for surface coal mining operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface...

  19. Determination of surface-accessible acidic hydroxyls and surface area of lignin by cationic dye adsorption.

    PubMed

    Sipponen, Mika Henrikki; Pihlajaniemi, Ville; Littunen, Kuisma; Pastinen, Ossi; Laakso, Simo

    2014-10-01

    A new colorimetric method for determining the surface-accessible acidic lignin hydroxyl groups in lignocellulose solid fractions was developed. The method is based on selective adsorption of Azure B, a basic dye, onto acidic hydroxyl groups of lignin. Selectivity of adsorption of Azure B on lignin was demonstrated using lignin and cellulose materials as adsorbents. Adsorption isotherms of Azure B on wheat straw (WS), sugarcane bagasse (SGB), oat husk, and isolated lignin materials were determined. The maximum adsorption capacities predicted by the Langmuir isotherms were used to calculate the amounts of surface-accessible acidic hydroxyl groups. WS contained 1.7-times more acidic hydroxyls (0.21 mmol/g) and higher surface area of lignin (84 m(2)/g) than SGB or oat husk materials. Equations for determining the amount of surface-accessible acidic hydroxyls in solid fractions of the three plant materials by a single point measurement were developed. A method for high-throughput characterization of lignocellulosic materials is now available.

  20. Mercury Underpotential Deposition to Determine Iridium and Iridium Oxide Electrochemical Surface Areas

    SciTech Connect

    Alia, Shaun M.; Hurst, Katherine E.; Kocha, Shyam S.; Pivovar, Bryan S.

    2016-06-02

    Determining the surface areas of electrocatalysts is critical for separating the key properties of area-specific activity and electrochemical surface area from mass activity. Hydrogen underpotential deposition and carbon monoxide oxidation are typically used to evaluate iridium (Ir) surface areas, but are ineffective on oxides and can be sensitive to surface oxides formed on Ir metals. Mercury underpotential deposition is presented in this study as an alternative, able to produce reasonable surface areas on Ir and Ir oxide nanoparticles, and able to produce similar surface areas prior to and following characterization in oxygen evolution. Reliable electrochemical surface areas allow for comparative studies of different catalyst types and the characterization of advanced oxygen evolution catalysts. Lastly, they also enable the study of catalyst degradation in durability testing, both areas of increasing importance within electrolysis and electrocatalysis.

  1. Mercury Underpotential Deposition to Determine Iridium and Iridium Oxide Electrochemical Surface Areas

    DOE PAGES

    Alia, Shaun M.; Hurst, Katherine E.; Kocha, Shyam S.; ...

    2016-06-02

    Determining the surface areas of electrocatalysts is critical for separating the key properties of area-specific activity and electrochemical surface area from mass activity. Hydrogen underpotential deposition and carbon monoxide oxidation are typically used to evaluate iridium (Ir) surface areas, but are ineffective on oxides and can be sensitive to surface oxides formed on Ir metals. Mercury underpotential deposition is presented in this study as an alternative, able to produce reasonable surface areas on Ir and Ir oxide nanoparticles, and able to produce similar surface areas prior to and following characterization in oxygen evolution. Reliable electrochemical surface areas allow for comparativemore » studies of different catalyst types and the characterization of advanced oxygen evolution catalysts. Lastly, they also enable the study of catalyst degradation in durability testing, both areas of increasing importance within electrolysis and electrocatalysis.« less

  2. Cell viability score (CVS) as a good indicator of critical concentration of benzalkonium chloride for toxicity in cultured ocular surface cell lines.

    PubMed

    Iwasawa, Atsuo; Ayaki, Masahiko; Niwano, Yoshimi

    2013-07-01

    Cytotoxicity of benzalkonium chloride (BAK) is a major factor affecting drug cytotoxicity. This study aimed to determine the critical concentration of BAK for cultured ocular cells, using SIRC (rabbit corneal epithelium), BCE C/D-1b (bovine corneal epithelial cells), RC-1 (rabbit corneal epithelium), and Chang (human conjunctival cells). Cell viability was determined following the exposure of cells to 11 concentrations of BAK for 10, 30, or 60 min using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and neutral red assays, and the cell viability score (CVS) was used to evaluate comprehensively the toxicity of BAK. The CVS system consists of two values. The CVS50 was determined by the number of measurements for viability ≥50% of control. The CVS40/80 was calculated as follows: CVS40/80=(number of measurements for viability values >80%)-(number of measurements for viability values <40%). Both %CVS50 and %CVS40/80 decreased with concentrations of BAK. When BAK concentrations were 0.01% or higher, %CVS50 and %CVS40/80 became 0 and less than -90, respectively. Meanwhile, when BAK concentrations were 0.001% or lower, %CVS50 became 100. In the case of %CVS40/80, when the BAK concentrations were 0.002% or lower, the values reached 75 or more, and when 0.0005% or lower, the %CVS40/80 value reached 100. Accordingly, BAK induced very low cytotoxicity in the cultured ocular cell lines at concentrations of 0.002% or lower. The concentration-dependency confirmed that the CVS score is useful for expressing drug cytotoxicity in a simple and comprehensive manner.

  3. Summertime evolution of snow specific surface area close to the surface on the Antarctic Plateau

    NASA Astrophysics Data System (ADS)

    Libois, Q.; Picard, G.; Arnaud, L.; Dumont, M.; Lafaysse, M.; Morin, S.; Lefebvre, E.

    2015-08-01

    On the Antarctic Plateau, snow specific surface area (SSA) close to the surface shows complex variations at daily to seasonal scales which affect the surface albedo and in turn the surface energy budget of the ice sheet. While snow metamorphism, precipitation and strong wind events are known to drive SSA variations, usually in opposite ways, their relative contributions remain unclear. Here, a comprehensive set of SSA observations at Dome C is analysed with respect to meteorological conditions to assess the respective roles of these factors. The results show an average two-to-three-fold SSA decrease from October to February in the topmost 10 cm, in response to the increase of air temperature and absorption of solar radiation in the snowpack during spring and summer. Surface SSA is also characterised by significant daily to weekly variations, due to the deposition of small crystals with SSA up to 100 m2 kg-1 onto the surface during snowfall and blowing snow events. To complement these field observations, the detailed snowpack model Crocus is used to simulate SSA, with the intent to further investigate the previously found correlation between inter-annual variability of summer SSA decrease and summer precipitation amount. To this end, Crocus parameterizations have been adapted to Dome C conditions, and the model was forced by ERA-Interim reanalysis. It successfully matches the observations at daily to seasonal time scales, except for few cases when snowfalls are not captured by the reanalysis. On the contrary, the inter-annual variability of summer SSA decrease is poorly simulated when compared to 14 years of microwave satellite data sensititve to the near surface SSA. A simulation with disabled summer precipitation confirms the weak influence in the model of the precipitation on metamorphism, with only 6 % enhancement. However we found that disabling strong wind events in the model is sufficient to reconciliate the simulations with the observations. This suggests

  4. Summertime evolution of snow specific surface area close to the surface on the Antarctic Plateau

    NASA Astrophysics Data System (ADS)

    Libois, Q.; Picard, G.; Arnaud, L.; Dumont, M.; Lafaysse, M.; Morin, S.; Lefebvre, E.

    2015-12-01

    On the Antarctic Plateau, snow specific surface area (SSA) close to the surface shows complex variations at daily to seasonal scales which affect the surface albedo and in turn the surface energy budget of the ice sheet. While snow metamorphism, precipitation and strong wind events are known to drive SSA variations, usually in opposite ways, their relative contributions remain unclear. Here, a comprehensive set of SSA observations at Dome C is analysed with respect to meteorological conditions to assess the respective roles of these factors. The results show an average 2-to-3-fold SSA decrease from October to February in the topmost 10 cm in response to the increase of air temperature and absorption of solar radiation in the snowpack during spring and summer. Surface SSA is also characterized by significant daily to weekly variations due to the deposition of small crystals with SSA up to 100 m2 kg-1 onto the surface during snowfall and blowing snow events. To complement these field observations, the detailed snowpack model Crocus is used to simulate SSA, with the intent to further investigate the previously found correlation between interannual variability of summer SSA decrease and summer precipitation amount. To this end, some Crocus parameterizations have been adapted to Dome C conditions, and the model was forced by ERA-Interim reanalysis. It successfully matches the observations at daily to seasonal timescales, except for the few cases when snowfalls are not captured by the reanalysis. On the contrary, the interannual variability of summer SSA decrease is poorly simulated when compared to 14 years of microwave satellite data sensitive to the near-surface SSA. A simulation with disabled summer precipitation confirms the weak influence in the model of the precipitation on metamorphism, with only 6 % enhancement. However, we found that disabling strong wind events in the model is sufficient to reconciliate the simulations with the observations. This suggests that

  5. Study of normal ocular thermogram using textural parameters

    NASA Astrophysics Data System (ADS)

    Tan, Jen-Hong; Ng, E. Y. K.; Rajendra Acharya, U.; Chee, C.

    2010-03-01

    Ocular surface temperature (OST) has been studied with numerous approach and Infrared (IR) thermography has proved to be the best way to capture temperature distribution over some surfaces. It is applied to a number of biomedical applications including studies in the field of ophthalmology. However, the analysis of an ocular thermogram is largely in nascent stage, and is usually achieved by first-order texture analysis. This current study conducted second-order texture analysis on ocular thermal images, mainly by cross co-occurrence matrix together with first-order texture analysis, moments and difference histogram. It was found that, for subjects aged above 35 years old their interocular difference in median, textural contrast, moment 2 and moment 3 (in absolute value) were significantly higher than younger peers. Several significant linear correlations among investigated features were observed. The features extracted from cross co-occurrence matrix may play an important role in the diagnosis of ocular diseases.

  6. Oseltamivir inhibits influenza virus replication and transmission following ocular-only aerosol inoculation of ferrets.

    PubMed

    Belser, Jessica A; Maines, Taronna R; Creager, Hannah M; Katz, Jacqueline M; Tumpey, Terrence M

    2015-10-01

    Ocular exposure to influenza virus represents an alternate route of virus entry capable of establishing a respiratory infection in mammals, but the effectiveness of currently available antiviral treatments to limit virus replication within ocular tissue or inhibit virus spread from ocular sites to the respiratory tract is poorly understood. Using an inoculation method that delivers an aerosol inoculum exclusively to the ocular surface, we demonstrate that oral oseltamivir administration following ocular-only aerosol inoculation with multiple avian and human influenza viruses protected ferrets from a fatal and systemic infection, reduced clinical signs and symptoms of illness, and decreased virus transmissibility to susceptible contacts when a respiratory infection was initiated. The presence of oseltamivir further inhibited influenza virus replication in primary human corneal epithelial cells. These findings provide critical experimental evidence supporting the use of neuraminidase inhibitors during outbreaks of influenza virus resulting in ocular disease or following ocular exposure.

  7. Ocular delivery of macromolecules

    PubMed Central

    Kim, Yoo-Chun; Chiang, Bryce; Wu, Xianggen; Prausnitz, Mark R.

    2014-01-01

    Biopharmaceuticals are making increasing impact on medicine, including treatment of indications in the eye. Macromolecular drugs are typically given by physician-administered invasive delivery methods, because non--invasive ocular delivery methods, such as eye drops, and systemic delivery, have low bioavailability and/or poor ocular targeting. There is a need to improve delivery of biopharmaceuticals to enable less-invasive delivery routes, less-frequent dosing through controlled-release drug delivery and improved drug targeting within the eye to increase efficacy and reduce side effects. This review discusses the barriers to drug delivery via various ophthalmic routes of administration in the context of macromolecule delivery and discusses efforts to develop controlled-release systems for delivery of biopharmaceuticals to the eye. The growing number of macromolecular therapies in the eye needs improved drug delivery methods that increase drug efficacy, safety and patient compliance. PMID:24998941

  8. Ocular sparganosis from Assam

    PubMed Central

    Nath, Reema; Gogoi, Rajendra Nath

    2015-01-01

    Sparganosis is caused by plerocercoid larvae of the Pseudophyllidea tapeworms of the genus Spirometra. Though prevalent in East Asian and south east Asian countries like China, Japan, Korea, Taiwan, Vietnam, Thailand; yet very few cases are reported from India. We report a case of migrating sub-conjunctival ocular sparganosis mimicking scleritis which later on developed into orbital cellulitis from Dibrugarh, Assam, North-eastern part of India. This case is reported for its rarity. PMID:25709957

  9. Human ocular anatomy.

    PubMed

    Kels, Barry D; Grzybowski, Andrzej; Grant-Kels, Jane M

    2015-01-01

    We review the normal anatomy of the human globe, eyelids, and lacrimal system. This contribution explores both the form and function of numerous anatomic features of the human ocular system, which are vital to a comprehensive understanding of the pathophysiology of many oculocutaneous diseases. The review concludes with a reference glossary of selective ophthalmologic terms that are relevant to a thorough understanding of many oculocutaneous disease processes.

  10. Measurement of surface cleanliness by area-of-spread

    SciTech Connect

    Harding, W.B.

    1992-02-01

    The technique of determining the amount of spreading of a small (0.5 to 5 mm{sup 3}) drop of water on a surface as a measure of the cleanliness of the surface is described. Calculation of the wetting angle of the drop from the diameter and volume of the drop is explained. Values of wetting angles for several clean and several deliberately contaminated surfaces are presented. Illustrative photomicrographs are included.

  11. Characterization of ocular gland morphology and tear composition of pinnipeds

    PubMed Central

    Davis, Robin Kelleher; Doane, Marshall G.; Knop, Erich; Knop, Nadja; Dubielzig, Richard R.; Colitz, Carmen M. H.; Argüeso, Pablo; Sullivan, David A.

    2012-01-01

    Objective The importance of tear film integrity to ocular health in terrestrial mammals is well established, however, in marine mammals, the role of the tear film in protection of the ocular surface is not known. In an effort to better understand the function of tears in maintaining health of the marine mammal eye surface, we examined ocular glands of the California sea lion, and began to characterize the biochemical nature of the tear film of pinnipeds. Procedures Glands dissected from California sea lion eyelids and adnexa were examined for gross morphology, sectioned for microscopic analysis, and stained with haematoxylin and eosin. The tear film was examined using interferometry. Tears were collected from humans and pinnipeds for analysis of protein and carbohydrate content. Results The sea lion has sebaceous glands in the lid, but these glands are different in size and orientation compared to typical meibomian glands of terrestrial mammals. Two other accessory ocular glands located dorsotemporally and medially appeared to be identical in morphology, with tubulo-acinar morphology. An outer lipid layer on the ocular surface of the sea lion was not detected using interferometry, consistent with the absence of typical meibomian glands. Similar to human tears, the tears of pinnipeds contain several proteins but the ratio of carbohydrate to protein was greater than that in human tears. Conclusions Our findings indicate that the ocular gland architecture and biochemical nature of the tear film of pinnipeds have evolved to adapt to the challenges of an aquatic environment. PMID:23067374

  12. Fabrication technology to increase surface area of ionomer membrane material and its application towards high surface area electric double-layer capacitors

    NASA Astrophysics Data System (ADS)

    Chang, Alberto A.; Patel, Jasbir N.; Cordoba, Cristina; Kaminska, Bozena; Kavanagh, Karen

    2014-03-01

    An application friendly technique to increase the surface area of the ionomer membrane such as Aquivion™ has been developed. By utilizing existing micro-fabrication technologies, square pillars were fabricated onto glass and silicon substrates. In combination with a low cost heat press, the glass and silicon stamps were used to successfully hot emboss micro-features onto the ionomer membrane. Consequently, the surface area of the Aquivion™ membrane was drastically increased enabling potential improvement of sensing and energy storage technologies. Preliminary results show successful fabrication of devices with systematic higher surface area and an improved capacitance.

  13. Orchestrating epigenetic roles targeting ocular tumors

    PubMed Central

    Wen, Xuyang; Lu, Linna; He, Zhang; Fan, Xianqun

    2016-01-01

    Epigenetics is currently one of the most promising areas of study in the field of biomedical research. Scientists have dedicated their efforts to studying epigenetic mechanisms in cancer for centuries. Additionally, the field has expanded from simply studying DNA methylation to other areas, such as histone modification, non-coding RNA, histone variation, nucleosome location, and chromosome remodeling. In ocular tumors, a large amount of epigenetic exploration has expanded from single genes to the genome-wide level. Most importantly, because epigenetic changes are reversible, several epigenetic drugs have been developed for the treatment of cancer. Herein, we review the current understanding of epigenetic mechanisms in ocular tumors, including but not limited to retinoblastoma and uveal melanoma. Furthermore, the development of new pharmacological strategies is summarized. PMID:27013893

  14. Properties that influence the specific surface areas of carbon nanotubes and nanofibers.

    PubMed

    Birch, M Eileen; Ruda-Eberenz, Toni A; Chai, Ming; Andrews, Ronnee; Hatfield, Randal L

    2013-11-01

    Commercially available carbon nanotubes and nanofibers were analyzed to examine possible relationships between their Brunauer-Emmett-Teller specific surface areas (SSAs) and their physical and chemical properties. Properties found to influence surface area were number of walls/diameter, impurities, and surface functionalization with hydroxyl and carboxyl groups. Characterization by electron microscopy, energy-dispersive X-ray spectrometry, thermogravimetric analysis, and elemental analysis indicates that SSA can provide insight on carbon nanomaterials properties, which can differ vastly depending on synthesis parameters and post-production treatments. In this study, how different properties may influence surface area is discussed. The materials examined have a wide range of surface areas. The measured surface areas differed from product specifications, to varying degrees, and between similar products. Findings emphasize the multiple factors that influence surface area and mark its utility in carbon nanomaterial characterization, a prerequisite to understanding their potential applications and toxicities. Implications for occupational monitoring are discussed.

  15. Properties that Influence the Specific Surface Areas of Carbon Nanotubes and Nanofibers

    PubMed Central

    BIRCH, M. EILEEN; RUDA-EBERENZ, TONI A.; CHAI, MING; ANDREWS, RONNEE; HATFIELD, RANDAL L.

    2015-01-01

    Commercially available carbon nanotubes and nanofibers were analyzed to examine possible relationships between their Brunauer–Emmett–Teller specific surface areas (SSAs) and their physical and chemical properties. Properties found to influence surface area were number of walls/diameter, impurities, and surface functionalization with hydroxyl and carboxyl groups. Characterization by electron microscopy, energy-dispersive X-ray spectrometry, thermogravimetric analysis, and elemental analysis indicates that SSA can provide insight on carbon nanomaterials properties, which can differ vastly depending on synthesis parameters and post-production treatments. In this study, how different properties may influence surface area is discussed. The materials examined have a wide range of surface areas. The measured surface areas differed from product specifications, to varying degrees, and between similar products. Findings emphasize the multiple factors that influence surface area and mark its utility in carbon nanomaterial characterization, a prerequisite to understanding their potential applications and toxicities. Implications for occupational monitoring are discussed. PMID:24029925

  16. 30 CFR 761.11 - Areas where surface coal mining operations are prohibited or limited.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Areas where surface coal mining operations are....11 Areas where surface coal mining operations are prohibited or limited. You may not conduct surface coal mining operations on the following lands unless you either have valid existing rights,...

  17. 30 CFR 761.11 - Areas where surface coal mining operations are prohibited or limited.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Areas where surface coal mining operations are....11 Areas where surface coal mining operations are prohibited or limited. You may not conduct surface coal mining operations on the following lands unless you either have valid existing rights,...

  18. 30 CFR 717.15 - Disposal of excess rock and earth materials on surface areas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Disposal of excess rock and earth materials on surface areas. 717.15 Section 717.15 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS § 717.15 Disposal of excess rock and earth materials on surface areas. Excess rock and...

  19. 30 CFR 717.15 - Disposal of excess rock and earth materials on surface areas.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Disposal of excess rock and earth materials on surface areas. 717.15 Section 717.15 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS § 717.15 Disposal of excess rock and earth materials on surface areas. Excess rock and...

  20. 30 CFR 717.15 - Disposal of excess rock and earth materials on surface areas.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Disposal of excess rock and earth materials on surface areas. 717.15 Section 717.15 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS § 717.15 Disposal of excess rock and earth materials on surface areas. Excess rock and...

  1. 30 CFR 717.15 - Disposal of excess rock and earth materials on surface areas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Disposal of excess rock and earth materials on surface areas. 717.15 Section 717.15 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS § 717.15 Disposal of excess rock and earth materials on surface areas. Excess rock and...

  2. 30 CFR 717.15 - Disposal of excess rock and earth materials on surface areas.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Disposal of excess rock and earth materials on surface areas. 717.15 Section 717.15 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS § 717.15 Disposal of excess rock and earth materials on surface areas. Excess rock and...

  3. 30 CFR 761.11 - Areas where surface coal mining operations are prohibited or limited.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Areas where surface coal mining operations are....11 Areas where surface coal mining operations are prohibited or limited. You may not conduct surface coal mining operations on the following lands unless you either have valid existing rights,...

  4. 30 CFR 761.11 - Areas where surface coal mining operations are prohibited or limited.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Areas where surface coal mining operations are....11 Areas where surface coal mining operations are prohibited or limited. You may not conduct surface coal mining operations on the following lands unless you either have valid existing rights,...

  5. 30 CFR 761.11 - Areas where surface coal mining operations are prohibited or limited.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas where surface coal mining operations are prohibited or limited. 761.11 Section 761.11 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR AREAS UNSUITABLE FOR MINING AREAS DESIGNATED BY ACT OF CONGRESS §...

  6. Formulation and evaluation of Cyclosporin A emulgel for ocular delivery.

    PubMed

    Shen, Yan; Ling, Xiang; Jiang, Weiwei; Du, Shuang; Lu, Yang; Tu, Jiasheng

    2015-01-01

    Emulgels have been extensively covered as a promising drug delivery system for the administration of lipophilic drugs. This work was conducted to develop an emulgel formulation for Cyclosporin A (CsA) employing polycarbophil as the gelling agent for ocular delivery. The prepared emulgels were evaluated for their physical appearance, rheological behavior, drug release, stability, precorneal clearance and irritation. Results showed that CsA emulgel formulations prepared with polycarbophil exhibited acceptable physical properties and drug release, which remained consistent after storage for 3 months. A prolonged retention time was also observed on the ocular surface with improved ocular bioavailability and no irritation. Therefore, the polycarbophil-based emulgel could be exploited as a potential hydrophobic drug carrier for topical ocular drug delivery.

  7. Nontuberculous Mycobacterial Ocular Infections: A Systematic Review of the Literature

    PubMed Central

    Kheir, Wajiha J.; Sheheitli, Huda; Abdul Fattah, Maamoun; Hamam, Rola N.

    2015-01-01

    Nontuberculous or atypical mycobacterial ocular infections have been increasing in prevalence over the past few decades. They are known to cause periocular, adnexal, ocular surface and intraocular infections and are often recalcitrant to medical therapy. These infections can potentially cause detrimental outcomes, in part due to a delay in diagnosis. We review 174 case reports and series on nontuberculous mycobacterial (NTM) ocular infections and discuss etiology, microbiology, risk factors, diagnosis, clinical presentation, and treatment of these infections. History of interventions, trauma, foreign bodies, implants, contact lenses, and steroids are linked to NTM ocular infections. Steroid use may prolong the duration of the infection and cause poorer visual outcomes. Early diagnosis and initiation of treatment with multiple antibiotics are necessary to achieve the best visual outcome. PMID:26106601

  8. Ocular medications in children.

    PubMed

    Wallace, D K; Steinkuller, P G

    1998-11-01

    Many ocular medications are used by pediatricians or ophthalmologists caring for pediatric patients. Topical antibiotics are commonly prescribed for bacterial conjunctivitis, nasolacrimal duct obstructions, and ophthalmia neonatorum. Many new antiallergy eye drops are now available for the treatment of seasonal (hay fever) conjunctivitis. Dilating eye drops and antiglaucoma medications are generally used or prescribed by ophthalmologists, but pediatricians must be aware of their potentially serious systemic side effects. Before initiating treatment, physicians should evaluate the risks and benefits of ophthalmic medications, establish minimum dosages necessary to achieve a therapeutic benefit, and monitor children for local and systemic side effects.

  9. 30 CFR 921.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for surface coal mining operations. 921.762 Section 921.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mine operations....

  10. 30 CFR 933.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for surface coal mining operations. 933.762 Section 933.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designation Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  11. 30 CFR 941.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for surface coal mining operations. 941.762 Section 941.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mine operations....

  12. 30 CFR 933.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for surface coal mining operations. 933.762 Section 933.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designation Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  13. 30 CFR 933.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for surface coal mining operations. 933.762 Section 933.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designation Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  14. 30 CFR 941.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for surface coal mining operations. 941.762 Section 941.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mine operations....

  15. 30 CFR 939.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for surface coal mining operations. 939.762 Section 939.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  16. 30 CFR 905.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for surface coal mining operations. 905.762 Section 905.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining operations....

  17. 30 CFR 921.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for surface coal mining operations. 921.762 Section 921.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mine operations....

  18. 30 CFR 942.764 - Process for designating areas unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... surface coal mining operations. 942.764 Section 942.764 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE TENNESSEE § 942.764 Process for designating areas unsuitable for surface coal mining... Mining Operations, shall apply to surface coal mining and reclamation operations. (b) The Secretary...

  19. 30 CFR 942.764 - Process for designating areas unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... surface coal mining operations. 942.764 Section 942.764 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE TENNESSEE § 942.764 Process for designating areas unsuitable for surface coal mining... Mining Operations, shall apply to surface coal mining and reclamation operations. (b) The Secretary...

  20. 30 CFR 939.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for surface coal mining operations. 939.762 Section 939.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  1. 30 CFR 942.764 - Process for designating areas unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... surface coal mining operations. 942.764 Section 942.764 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE TENNESSEE § 942.764 Process for designating areas unsuitable for surface coal mining... Mining Operations, shall apply to surface coal mining and reclamation operations. (b) The Secretary...

  2. 30 CFR 941.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for surface coal mining operations. 941.762 Section 941.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mine operations....

  3. 30 CFR 947.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for surface coal mining operations. 947.762 Section 947.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  4. 30 CFR 933.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for surface coal mining operations. 933.762 Section 933.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designation Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  5. 30 CFR 933.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for surface coal mining operations. 933.762 Section 933.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designation Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  6. 30 CFR 905.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for surface coal mining operations. 905.762 Section 905.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining operations....

  7. 30 CFR 905.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for surface coal mining operations. 905.762 Section 905.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining operations....

  8. 30 CFR 947.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for surface coal mining operations. 947.762 Section 947.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  9. 30 CFR 939.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for surface coal mining operations. 939.762 Section 939.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  10. 30 CFR 921.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for surface coal mining operations. 921.762 Section 921.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mine operations....

  11. 30 CFR 942.764 - Process for designating areas unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... surface coal mining operations. 942.764 Section 942.764 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE TENNESSEE § 942.764 Process for designating areas unsuitable for surface coal mining... Mining Operations, shall apply to surface coal mining and reclamation operations. (b) The Secretary...

  12. 30 CFR 939.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for surface coal mining operations. 939.762 Section 939.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  13. 30 CFR 947.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for surface coal mining operations. 947.762 Section 947.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  14. 30 CFR 947.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for surface coal mining operations. 947.762 Section 947.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  15. 30 CFR 941.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for surface coal mining operations. 941.762 Section 941.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mine operations....

  16. 30 CFR 942.764 - Process for designating areas unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... surface coal mining operations. 942.764 Section 942.764 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE TENNESSEE § 942.764 Process for designating areas unsuitable for surface coal mining... Mining Operations, shall apply to surface coal mining and reclamation operations. (b) The Secretary...

  17. 30 CFR 921.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for surface coal mining operations. 921.762 Section 921.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mine operations....

  18. 30 CFR 939.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for surface coal mining operations. 939.762 Section 939.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  19. 30 CFR 941.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for surface coal mining operations. 941.762 Section 941.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mine operations....

  20. 30 CFR 921.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for surface coal mining operations. 921.762 Section 921.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mine operations....

  1. 30 CFR 905.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for surface coal mining operations. 905.762 Section 905.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining operations....

  2. 30 CFR 905.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for surface coal mining operations. 905.762 Section 905.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining operations....

  3. 30 CFR 947.762 - Criteria for designating areas as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for surface coal mining operations. 947.762 Section 947.762 Mineral Resources OFFICE OF SURFACE MINING... mining operations. Part 762 of this chapter, Criteria for Designating Areas Unsuitable for Surface Coal Mining Operations, shall apply to surface coal mining and reclamation operations....

  4. Large-area fabrication of superhydrophobic surfaces for practical applications: an overview

    PubMed Central

    Xue, Chao-Hua; Jia, Shun-Tian; Zhang, Jing; Ma, Jian-Zhong

    2010-01-01

    This review summarizes the key topics in the field of large-area fabrication of superhydrophobic surfaces, concentrating on substrates that have been used in commercial applications. Practical approaches to superhydrophobic surface construction and hydrophobization are discussed. Applications of superhydrophobic surfaces are described and future trends in superhydrophobic surfaces are predicted. PMID:27877336

  5. 30 CFR 905.764 - Process for designating areas unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... surface coal mining operations. 905.764 Section 905.764 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE CALIFORNIA § 905.764 Process for designating areas unsuitable for surface coal...

  6. 30 CFR 910.764 - Process for designating areas unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... surface coal mining operations. 910.764 Section 910.764 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE GEORGIA § 910.764 Process for designating areas unsuitable for surface coal...

  7. 30 CFR 912.764 - Process for designating areas unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... surface coal mining operations. 912.764 Section 912.764 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE IDAHO § 912.764 Process for designating areas unsuitable for surface coal...

  8. 30 CFR 903.764 - Process for designating areas unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... surface coal mining operations. 903.764 Section 903.764 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS WITHIN EACH STATE ARIZONA § 903.764 Process for designating areas unsuitable for surface coal...

  9. Large-area fabrication of superhydrophobic surfaces for practical applications: an overview.

    PubMed

    Xue, Chao-Hua; Jia, Shun-Tian; Zhang, Jing; Ma, Jian-Zhong

    2010-06-01

    This review summarizes the key topics in the field of large-area fabrication of superhydrophobic surfaces, concentrating on substrates that have been used in commercial applications. Practical approaches to superhydrophobic surface construction and hydrophobization are discussed. Applications of superhydrophobic surfaces are described and future trends in superhydrophobic surfaces are predicted.

  10. MRI in ocular drug delivery

    PubMed Central

    Li, S. Kevin; Lizak, Martin J.; Jeong, Eun-Kee

    2008-01-01

    Conventional pharmacokinetic methods for studying ocular drug delivery are invasive and cannot be conveniently applied to humans. The advancement of MRI technology has provided new opportunities in ocular drug-delivery research. MRI provides a means to non-invasively and continuously monitor ocular drug-delivery systems with a contrast agent or compound labeled with a contrast agent. It is a useful technique in pharmacokinetic studies, evaluation of drug-delivery methods, and drug-delivery device testing. Although the current status of the technology presents some major challenges to pharmaceutical research using MRI, it has a lot of potential. In the past decade, MRI has been used to examine ocular drug delivery via the subconjunctival route, intravitreal injection, intrascleral injection to the suprachoroidal space, episcleral and intravitreal implants, periocular injections, and ocular iontophoresis. In this review, the advantages and limitations of MRI in the study of ocular drug delivery are discussed. Different MR contrast agents and MRI techniques for ocular drug-delivery research are compared. Ocular drug-delivery studies using MRI are reviewed. PMID:18186077

  11. A Novel Cell-Associated Protection Assay Demonstrates the Ability of Certain Antibiotics To Protect Ocular Surface Cell Lines from Subsequent Clinical Staphylococcus aureus Challenge▿†

    PubMed Central

    Wingard, J. B.; Romanowski, E. G.; Kowalski, R. P.; Mah, F. S.; Ling, Y.; Bilonick, R. A.; Shanks, R. M. Q.

    2011-01-01

    In vivo effectiveness of topical antibiotics may depend on their ability to associate with epithelial cells to provide continued protection, but this contribution is not measured by standard antibiotic susceptibility tests. We report a new in vitro method that measures the ability of test antibiotics azithromycin (AZM), erythromycin (ERY), tetracycline (TET), and bacitracin (BAC) to associate with mammalian cells and to protect these cells from destruction by bacteria. Mammalian cell lines were grown to confluence using antibiotic-free medium and then incubated in medium containing a single antibiotic (0 to 512 μg/ml). After incubation, the cells were challenged with Staphylococcus aureus ocular isolates, without antibiotics added to the culture medium. Epithelial cell layer integrity was assessed by gentian violet staining, and the minimum cell layer protective concentration (MCPC) of an antibiotic sufficient to protect the mammalian cells from S. aureus was determined. Staining was also quantified and analyzed. Bacterial viability was determined by culture turbidity and growth on agar plates. Preincubation of Chang and human corneal limbal epithelial cells with AZM, ERY, and TET at ≥64 μg/ml provided protection against AZM-susceptible S. aureus strains, with increasing protection at higher concentrations. TET toxicity was demonstrated at >64 μg/ml, whereas AZM displayed toxicity to one cell line at 512 μg/ml. BAC failed to show consistent protection at any dose, despite bacterial susceptibility to BAC as determined by traditional antibiotic susceptibility testing. A range of antibiotic effectiveness was displayed in this cell association assay, providing data that may be considered in addition to traditional testing when determining therapeutic dosing regimens. PMID:21628536

  12. Nonhuman Primate Ocular Biometry

    PubMed Central

    Augusteyn, Robert C.; Maceo Heilman, Bianca; Ho, Arthur; Parel, Jean-Marie

    2016-01-01

    Purpose To examine ocular growth in nonhuman primates (NHPs) from measurements on ex vivo eyes. Methods We obtained NHP eyes from animals that had been killed as part of other studies or because of health-related issues. Digital calipers were used to measure the horizontal, vertical, and anteroposterior globe diameters as well as corneal horizontal and vertical diameters of excised globes from 98 hamadryas baboons, 551 cynomolgus monkeys, and 112 rhesus monkeys, at ages ranging from 23 to 360 months. Isolated lens sagittal thickness and equatorial diameter were measured by shadowphotogrammetry. Wet and fixed dry weights were obtained for lenses. Results Nonhuman primate globe growth continues throughout life, slowing toward an asymptotic maximum. The final globe size scales with negative allometry to adult body size. Corneal growth ceases at around 20 months. Lens diameter increases but thickness decreases with increasing age. Nonhuman primate lens wet and dry weight accumulation is monophasic, continuing throughout life toward asymptotic maxima. The dry/wet weight ratio reaches a maximum of 0.33. Conclusions Nonhuman primate ocular globe and lens growth differ in several respects from those in humans. Although age-related losses of lens power and accommodative amplitude are similar, lens growth and properties are different indicating care should be taken in extrapolating NHP observations to the study of human accommodation. PMID:26780314

  13. On the influence of substrate morphology and surface area on phytofauna

    USGS Publications Warehouse

    Becerra-Munoz, S.; Schramm, H.L.

    2007-01-01

    The independent effects and interactions between substrate morphology and substrate surface area on invertebrate density or biomass colonizing artificial plant beds were assessed in a clear-water and a turbid playa lake in Castro County, Texas, USA. Total invertebrate density and biomass were consistently greater on filiform substrates than on laminar substrates with equivalent substrate surface areas. The relationship among treatments (substrates with different morphologies and surface areas) and response (invertebrate density or biomass) was assessed with equally spaced surface areas. Few statistically significant interactions between substrate morphology and surface area were detected, indicating that these factors were mostly independent from each other in their effect on colonizing invertebrates. Although infrequently, when substrate morphology and surface area were not independent, the effects of equally spaced changes in substrate surface area on the rate of change of phytofauna density or biomass per unit of substrate surface area were dependent upon substrate morphology. The absence of three-way interactions indicated that effects of substrate morphology and substrate area on phytofauna density or biomass were independent of environmental conditions outside and inside exclosures. ?? 2006 Springer Science+Business Media B.V.

  14. Novel Nanomicellar Formulation Approaches for Anterior and Posterior Segment Ocular Drug Delivery

    PubMed Central

    Cholkar, Kishore; Patel, Ashaben; Vadlapudi, Aswani Dutt; Mitra, Ashim K

    2014-01-01

    One of the most challenging areas of pharmaceutical research is ocular drug delivery. The unique anatomy and physiology of the eye impedes drug permeation to deeper ocular tissues. Nanosized carrier systems such as nanoparticles, liposomes, suspensions, dendrimers, and nanomicelles are being explored for ocular drug delivery. In this review, we have focused on application of emerging nanomicellar carrier systems in ocular drug delivery. Nanomicelles are nanosized vesicular carriers formed from amphiphilic monomer units. Surfactant and polymeric micellar nanocarriers provide an amenable means to improve drug solubilization, develop clear aqueous formulations and deliver drugs to anterior and posterior ocular tissues. Nanomicelles due to their amphiphilic nature encapsulate hydrophobic drugs and aid in drug delivery. Various methods are employed to develop nanosized micellar formulations depending upon the physicochemical properties of the drug. Nanomicellar carriers appear to be promising vehicles with potential applications in ocular drug delivery. In this review, we attempted to discuss about the progress in ocular drug delivery research using nanomicelles as carriers from the published literature and issued patents. Also, with regards to ocular static and dynamic barriers which prevent drug permeation, a brief discussion about nanomicelles, types of nanomicelles, their methods of preparation and micellar strategy to overcome ocular barriers, delivering therapeutic levels of drugs to anterior and posterior ocular tissues are discussed. PMID:25400717

  15. Pleistocene surface water temperatures in the Benguela upwelling area

    NASA Astrophysics Data System (ADS)

    Os'kina, N. S.; Dmitrenko, O. B.

    2011-08-01

    Analysis of carbonate microfossils (planktonic foraminifers and nannoplankton) in the DSDP Hole 362 Quaternary section made it possible to specify its zonal subdivision (almost all zones of Gartner's high-resolution nannofossil scale are recognized), establish depositional environments, and restore past surface water temperatures. The latter appeared to be several degrees lower than their present-day values, which is evident from the anomalously high share of the subpolar species Neogloboquadrina pachyderma sin. that constitutes 97% of the fossil assemblage in Lower Pleistocene sediments. It is shown that the Benguela upwelling existed throughout the entire Pleistocene, being less intense in the Late Pleistocene and Holocene.

  16. Limbal Fibroblasts Maintain Normal Phenotype in 3D RAFT Tissue Equivalents Suggesting Potential for Safe Clinical Use in Treatment of Ocular Surface Failure.

    PubMed

    Massie, Isobel; Dale, Sarah B; Daniels, Julie T

    2015-06-01

    Limbal epithelial stem cell deficiency can cause blindness, but transplantation of these cells on a carrier such as human amniotic membrane can restore vision. Unfortunately, clinical graft manufacture using amnion can be inconsistent. Therefore, we have developed an alternative substrate, Real Architecture for 3D Tissue (RAFT), which supports human limbal epithelial cells (hLE) expansion. Epithelial organization is improved when human limbal fibroblasts (hLF) are incorporated into RAFT tissue equivalent (TE). However, hLF have the potential to transdifferentiate into a pro-scarring cell type, which would be incompatible with therapeutic transplantation. The aim of this work was to assess the scarring phenotype of hLF in RAFT TEs in hLE+ and hLE- RAFT TEs and in nonairlifted and airlifted RAFT TEs. Diseased fibroblasts (dFib) isolated from the fibrotic conjunctivae of ocular mucous membrane pemphigoid (Oc-MMP) patients were used as a pro-scarring positive control against which hLF were compared using surrogate scarring parameters: matrix metalloproteinase (MMP) activity, de novo collagen synthesis, α-smooth muscle actin (α-SMA) expression, and transforming growth factor-β (TGF-β) secretion. Normal hLF and dFib maintained different phenotypes in RAFT TE. MMP-2 and -9 activity, de novo collagen synthesis, and α-SMA expression were all increased in dFib cf. normal hLF RAFT TEs, although TGF-β1 secretion did not differ between normal hLF and dFib RAFT TEs. Normal hLF do not progress toward a scarring-like phenotype during culture in RAFT TEs and, therefore, may be safe to include in therapeutic RAFT TE, where they can support hLE, although in vivo work is required to confirm this. dFib RAFT TEs (used in this study as a positive control) may be useful toward the development of an ex vivo disease model of Oc-MMP.

  17. Response surfaces for climate change impact assessments in urban areas.

    PubMed

    Semadeni-Davies, A

    2003-01-01

    Assessment of the impacts of climate change in real-world water systems, such as urban drainage networks, is a research priority for IPCC (Intergovernmental Panel of Climate Change). The usual approach is to force a hydrological transformation model with a changed climate scenario. To tackle uncertainty, the model should be run with at least high, middle and low change scenarios. This paper shows the value of response surfaces for displaying multiple simulated responses to incremental changes in air temperature and precipitation. The example given is inflow, related to sewer infiltration, at the Lycksele waste water treatment plant. The range of plausible changes in inflow is displayed for a series of runs for eight GCMs (Global Circulation Model; ACACIA; Carter, 2002, pers. comm.). These runs are summarised by climate envelopes, one for each prediction time-slice (2020, 2050, 2080). Together, the climate envelopes and response surfaces allow uncertainty to be easily seen. Winter inflows are currently sensitive to temperature, but if average temperature rises to above zero, inflow will be most sensitive to precipitation. Spring inflows are sensitive to changes in winter snow accumulation and melt. Inflow responses are highly dependent on the greenhouse gas emission scenario and GCM chosen.

  18. 30 CFR 72.620 - Drill dust control at surface mines and surface areas of underground mines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... § 72.620 Drill dust control at surface mines and surface areas of underground mines. Holes shall be collared and drilled wet, or other effective dust control measures shall be used, when drilling non-water-soluble material. Effective dust control measures shall be used when drilling water-soluble material....

  19. 30 CFR 72.620 - Drill dust control at surface mines and surface areas of underground mines.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... § 72.620 Drill dust control at surface mines and surface areas of underground mines. Holes shall be collared and drilled wet, or other effective dust control measures shall be used, when drilling non-water-soluble material. Effective dust control measures shall be used when drilling water-soluble material....

  20. 30 CFR 72.620 - Drill dust control at surface mines and surface areas of underground mines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... § 72.620 Drill dust control at surface mines and surface areas of underground mines. Holes shall be collared and drilled wet, or other effective dust control measures shall be used, when drilling non-water-soluble material. Effective dust control measures shall be used when drilling water-soluble material....

  1. 30 CFR 72.620 - Drill dust control at surface mines and surface areas of underground mines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... § 72.620 Drill dust control at surface mines and surface areas of underground mines. Holes shall be collared and drilled wet, or other effective dust control measures shall be used, when drilling non-water-soluble material. Effective dust control measures shall be used when drilling water-soluble material....

  2. 30 CFR 72.620 - Drill dust control at surface mines and surface areas of underground mines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... § 72.620 Drill dust control at surface mines and surface areas of underground mines. Holes shall be collared and drilled wet, or other effective dust control measures shall be used, when drilling non-water-soluble material. Effective dust control measures shall be used when drilling water-soluble material....

  3. Ocular involvement in pemphigus vulgaris.

    PubMed

    Akhyani, Maryam; Keshtkar-Jafari, Alireza; Chams-Davatchi, Cheyda; Lajevardi, Vahide; Beigi, Sara; Aghazadeh, Nessa; Rayati Damavandi, Maede; Arami, Shabnam

    2014-07-01

    Pemphigus vulgaris (PV) is an autoimmune disorder affecting the skin and mucous membranes. Ocular involvement in PV has been reported but its prevalence and clinical characteristics are not well defined. This prospective cross-sectional study of 103 PV patients was designed to determine the prevalence, clinical types and epidemiological trends of ocular involvement in a population of Iranian patients with PV. Ocular involvement was present in 17 (16.5%) patients. Conjunctivitis was the most prevalent type of ocular involvement (9/17, 52.9%), followed by erosion of the palpebral conjunctiva (7/17, 41.2%). Erosion of the bulbar conjunctiva was noted in only one patient (5.9%). The most commonly reported symptoms were eye irritation (76.5%) and redness (76.5%). No significant relation was found between ocular involvement and disease activity (partial remission or relapse). Mucoid discharge was significantly more common in patients with conjunctival erosions as compared to patients with conjunctivitis (P = 0.038). We conclude that ocular involvement is not rare in PV; 16.5% of PV patients develop ocular disease independent of the disease activity and extension. Conjunctivitis is the most common type of involvement, however, palpebral conjunctival erosion is more frequent than previously realized.

  4. 30 CFR 933.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... WITHIN EACH STATE NORTH CAROLINA § 933.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated Unsuitable for Coal Mining by Act of Congress, with the exception of §§ 761.11(c) and 761.12(f)(1), shall apply to surface coal mining and...

  5. 30 CFR 933.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WITHIN EACH STATE NORTH CAROLINA § 933.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated Unsuitable for Coal Mining by Act of Congress, with the exception of §§ 761.11(c) and 761.12(f)(1), shall apply to surface coal mining and...

  6. 30 CFR 933.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... WITHIN EACH STATE NORTH CAROLINA § 933.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated Unsuitable for Coal Mining by Act of Congress, with the exception of §§ 761.11(c) and 761.12(f)(1), shall apply to surface coal mining and...

  7. 30 CFR 933.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... WITHIN EACH STATE NORTH CAROLINA § 933.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated Unsuitable for Coal Mining by Act of Congress, with the exception of §§ 761.11(c) and 761.12(f)(1), shall apply to surface coal mining and...

  8. 30 CFR 933.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... WITHIN EACH STATE NORTH CAROLINA § 933.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated Unsuitable for Coal Mining by Act of Congress, with the exception of §§ 761.11(c) and 761.12(f)(1), shall apply to surface coal mining and...

  9. Age Differences in Prefrontal Surface Area and Thickness in Middle Aged to Older Adults

    PubMed Central

    Dotson, Vonetta M.; Szymkowicz, Sarah M.; Sozda, Christopher N.; Kirton, Joshua W.; Green, Mackenzie L.; O’Shea, Andrew; McLaren, Molly E.; Anton, Stephen D.; Manini, Todd M.; Woods, Adam J.

    2016-01-01

    Age is associated with reductions in surface area and cortical thickness, particularly in prefrontal regions. There is also evidence of greater thickness in some regions at older ages. Non-linear age effects in some studies suggest that age may continue to impact brain structure in later decades of life, but relatively few studies have examined the impact of age on brain structure within middle-aged to older adults. We investigated age differences in prefrontal surface area and cortical thickness in healthy adults between the ages of 51 and 81 years. Participants received a structural 3-Tesla magnetic resonance imaging scan. Based on a priori hypotheses, primary analyses focused on surface area and cortical thickness in the dorsolateral prefrontal cortex, anterior cingulate cortex, and orbitofrontal cortex. We also performed exploratory vertex-wise analyses of surface area and cortical thickness across the entire cortex. We found that older age was associated with smaller surface area in the dorsolateral prefrontal and orbitofrontal cortices but greater cortical thickness in the dorsolateral prefrontal and anterior cingulate cortices. Vertex-wise analyses revealed smaller surface area in primarily frontal regions at older ages, but no age effects were found for cortical thickness. Results suggest age is associated with reduced surface area but greater cortical thickness in prefrontal regions during later decades of life, and highlight the differential effects age has on regional surface area and cortical thickness. PMID:26834623

  10. Age Differences in Prefrontal Surface Area and Thickness in Middle Aged to Older Adults.

    PubMed

    Dotson, Vonetta M; Szymkowicz, Sarah M; Sozda, Christopher N; Kirton, Joshua W; Green, Mackenzie L; O'Shea, Andrew; McLaren, Molly E; Anton, Stephen D; Manini, Todd M; Woods, Adam J

    2015-01-01

    Age is associated with reductions in surface area and cortical thickness, particularly in prefrontal regions. There is also evidence of greater thickness in some regions at older ages. Non-linear age effects in some studies suggest that age may continue to impact brain structure in later decades of life, but relatively few studies have examined the impact of age on brain structure within middle-aged to older adults. We investigated age differences in prefrontal surface area and cortical thickness in healthy adults between the ages of 51 and 81 years. Participants received a structural 3-Tesla magnetic resonance imaging scan. Based on a priori hypotheses, primary analyses focused on surface area and cortical thickness in the dorsolateral prefrontal cortex, anterior cingulate cortex, and orbitofrontal cortex. We also performed exploratory vertex-wise analyses of surface area and cortical thickness across the entire cortex. We found that older age was associated with smaller surface area in the dorsolateral prefrontal and orbitofrontal cortices but greater cortical thickness in the dorsolateral prefrontal and anterior cingulate cortices. Vertex-wise analyses revealed smaller surface area in primarily frontal regions at older ages, but no age effects were found for cortical thickness. Results suggest age is associated with reduced surface area but greater cortical thickness in prefrontal regions during later decades of life, and highlight the differential effects age has on regional surface area and cortical thickness.

  11. A high-throughput and selective method for the measurement of surface areas of silver nanoparticles.

    PubMed

    Agustin, Yuana Elly; Tsai, Shen-Long

    2015-04-21

    A high-throughput and selective method based on biomolecule affinity coordination was employed for measuring nanoparticle surface area in solutions. In this design, silver binding peptides (AgBPs) are immobilized on bacterial cellulose via fusion with cellulose binding domains to capture silver nanoparticles whereas green fluorescent proteins are fused with AgBPs as reporters for surface area quantification.

  12. Ocular leech infestation

    PubMed Central

    Lee, Yueh-Chang; Chiu, Cheng-Jen

    2015-01-01

    This case report describes a female toddler with manifestations of ocular leech infestation. A 2-year-old girl was brought to our outpatient clinic with a complaint of irritable crying after being taken to a stream in Hualien 1 day previous, where she played in the water. The parents noticed that she rubbed her right eye a lot. Upon examination, the girl had good fix and follow in either eye. Slit-lamp examination showed conjunctival injection with a moving dark black–brown foreign body partly attached in the lower conjunctiva. After applying topical anesthetics, the leech, measuring 1 cm in length, was extracted under a microscope. The patient began using topical antibiotic and corticosteroid agents. By 1 week after extraction, the patient had no obvious symptoms or signs, except for a limited subconjunctival hemorrhage, and no corneal/scleral involvement was observed. PMID:25784786

  13. Corticosteroids for ocular toxoplasmosis

    PubMed Central

    Jasper, Smitha; Vedula, Satyanarayana S; John, Sheeja S; Horo, Saban; Sepah, Yasir J; Nguyen, Quan Dong

    2014-01-01

    Background Ocular infestation with Toxoplasma gondii, a parasite, may result in inflammation in the retina, choroid, and uvea and consequently lead to complications such as glaucoma, cataract, and posterior synechiae. Objectives The objective of this systematic review was to assess the effects of adjunctive use of corticosteroids for ocular toxoplasmosis. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 9), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE, (January 1950 to October 2012), EMBASE (January 1980 to October 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to October 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We searched the reference lists of included studies for any additional studies not identified by the electronic searches. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 11 October 2012. Selection criteria We planned to include randomized and quasi-randomized controlled trials. Eligible trials would have enrolled participants of any age who were immunocompetent and were diagnosed with active ocular toxoplasmosis. Included trials would have compared anti-parasitic therapy plus corticosteroids versus anti-parasitic therapy alone, or different doses or times of initiation of corticosteroids. Data collection and analysis Two authors independently screened titles and abstracts retrieved from the electronic searches. We retrieved full-text articles of studies categorized as ‘unsure’ or ‘include’ after review of the abstracts. Two authors independently reviewed each full-text article. Discrepancies were

  14. Ocular Screening System

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Used to detect eye problems in children through analysis of retinal reflexes, the system incorporates image processing techniques. VISISCREEN's photorefractor is basically a 35 millimeter camera with a telephoto lens and an electronic flash. By making a color photograph, the system can test the human eye for refractive error and obstruction in the cornea or lens. Ocular alignment problems are detected by imaging both eyes simultaneously. Electronic flash sends light into the eyes and the light is reflected from the retina back to the camera lens. Photorefractor analyzes the retinal reflexes generated by the subject's response to the flash and produces an image of the subject's eyes in which the pupils are variously colored. The nature of a defect, where such exists, is identifiable by atrained observer's visual examination.

  15. Sports related ocular injuries.

    PubMed

    Mishra, Avinash; Verma, Ashok K

    2012-07-01

    Every year > 600,000 sports and recreation related eye injuries occur, out of which roughly 13,500 of these result in permanent loss of sight. Up to 90% of these sports related eye injuries are preventable by using adequate eye protection equipment. Protective eyewear is made of polycarbonate, a highly impact-resistant plastic which is now easily available as prescription and non-prescription eyewear and all players should be encouraged to use them. The medical officers by educating their patients regarding the risks of eye injuries in various sports and the confirmed benefits of using protective equipment have the potential to prevent injury to over thousands of eyes every year. The medical fraternity can also play a very important role in educating the coaches, parents, and children and thus put an end to unnecessary blindness and vision loss from sports related ocular injuries, therefore ensuring a lifetime of healthy vision.

  16. Photorefractor ocular screening system

    NASA Technical Reports Server (NTRS)

    Richardson, John R. (Inventor); Kerr, Joseph H. (Inventor)

    1987-01-01

    A method and apparatus for detecting human eye defects, particularly detection of refractive error is presented. Eye reflex is recorded on color film when the eyes are exposed to a flash of light. The photographs are compared with predetermined standards to detect eye defects. The base structure of the ocular screening system is a folding interconnect structure, comprising hinged sections. Attached to one end of the structure is a head positioning station which comprises vertical support, a head positioning bracket having one end attached to the top of the support, and two head positioning lamps to verify precise head positioning. At the opposite end of the interconnect structure is a camera station with camera, electronic flash unit, and blinking fixation lamp, for photographing the eyes of persons being evaluated.

  17. The relation of stream sediment surface area, grain size and composition to trace element chemistry

    USGS Publications Warehouse

    Horowitz, A.J.; Elrick, K.A.

    1987-01-01

    Intensive studies of 17 geographically and hydrologically diverse stream bed sediments provide information on the relation between grain size, surface area, and operationally defined geochemical phases (e.g. Mn oxides, amorphous Fe oxides) to trace element concentrations. Of the size fractions investigated ( 125 ??m), each of the various phases contribute to overall sample surface area. For material having mean grain sizes in the very fine sand range and finer (<125 ??m), the same phases act as surface-area inhibitors by cementing fine grains together to form aggregates. This increases the mean grain size of the sample and reduces the surface area. The presence of these aggregates may explain why the <63 ??m or <125 ??m size fractions are more important to sediment-trace element levels and surface area than other finer fractions. ?? 1987.

  18. Ocular myasthenia gravis: A review

    PubMed Central

    Nair, Akshay Gopinathan; Patil-Chhablani, Preeti; Venkatramani, Devendra V; Gandhi, Rashmin Anilkumar

    2014-01-01

    Myasthenia gravis (MG) is a disease that affects the neuro-muscular junction resulting in classical symptoms of variable muscle weakness and fatigability. It is called the great masquerader owing to its varied clinical presentations. Very often, a patient of MG may present to the ophthalmologist given that a large proportion of patients with systemic myasthenia have ocular involvement either at presentation or during the later course of the disease. The treatment of ocular MG involves both the neurologist and ophthalmologist. Thus, the aim of this review was to highlight the current diagnosis, investigations, and treatment of ocular MG. PMID:25449931

  19. Ocular manifestations of feline herpesvirus.

    PubMed

    Andrew, S E

    2001-03-01

    Feline herpesvirus-1 (FHV-1) infection is ubiquitous in the domestic cat population worldwide. The most common clinical ocular manifestations of infection with FHV-1 are conjunctivitis and keratitis. This paper reviews the pathogenesis of feline herpesvirus-1 and discusses the various clinical ocular manifestations, diagnostic techniques and treatment of FHV-1-induced diseases. Ocular manifestations include: conjunctivitis, keratitis, stromal keratitis, keratoconjunctivitis sicca, ophthalmia neonatorium, symblepharon, corneal sequestrum, eosinophilic keratitis and anterior uveitis. Diagnostic techniques discussed include: virus isolation, fluorescent antibody testing, serum neutralising titers, ELISA and polymerase chain reaction. Various therapies are also discussed.

  20. Nanoparticles in the ocular drug delivery

    PubMed Central

    Zhou, Hong-Yan; Hao, Ji-Long; Wang, Shuang; Zheng, Yu; Zhang, Wen-Song

    2013-01-01

    Ocular drug transport barriers pose a challenge for drug delivery comprising the ocular surface epithelium, the tear film and internal barriers of the blood-aqueous and blood-retina barriers. Ocular drug delivery efficiency depends on the barriers and the clearance from the choroidal, conjunctival vessels and lymphatic. Traditional drug administration reduces the clinical efficacy especially for poor water soluble molecules and for the posterior segment of the eye. Nanoparticles (NPs) have been designed to overcome the barriers, increase the drug penetration at the target site and prolong the drug levels by few internals of drug administrations in lower doses without any toxicity compared to the conventional eye drops. With the aid of high specificity and multifunctionality, DNA NPs can be resulted in higher transfection efficiency for gene therapy. NPs could target at cornea, retina and choroid by surficial applications and intravitreal injection. This review is concerned with recent findings and applications of NPs drug delivery systems for the treatment of different eye diseases. PMID:23826539

  1. An innovative impression technique for fabrication of a custom made ocular prosthesis

    PubMed Central

    Tripuraneni, Sunil Chandra; Vadapalli, Sriharsha Babu; Ravikiran, P; Nirupama, N

    2015-01-01

    Various impression and fitting techniques have been described in the past for restoring ocular defects. The present article describes a new direct impression technique for recording and rehabilitating ocular defects, by custom-made ocular prosthesis. All the techniques described in the history, mainly concentrated in recording the tissue surface of the defect, which made it difficult to contour the palpebral surface resulting in the poor esthetics of the prosthesis. The present impression technique uses heavy bodied polyvinyl siloxane impression material, which facilitates accurate recording of the tissue surface and the palpebral surface of the defect, resulting in the fabrication of functionally and esthetically acceptable prosthesis. PMID:26265651

  2. Long-term studies on the effects of nonvolatile organic compounds on porous media surface areas.

    PubMed

    Khachikian, Crist S; Harmon, Thomas C

    2002-01-01

    This paper investigates the long-term behavior of porous media contaminated by nonvolatile organic compounds (NVOC) in terms of specific interfacial surface area. Specifically, a natural sand, Moffett sand (MS), was contaminated with naphthalene and the surface area was measured repeatedly over time using nitrogen adsorption-desorption techniques. A field-contaminated sand affected by lamp-black material (LB) from former manufactured gas plant operations was also studied. Lampblack is a carbonaceous skeleton containing polycyclic aromatic hydrocarbons (PAHs) and other hydrocarbons. It is hypothesized that soils contaminated by these types of chemicals will exhibit significantly less surface area than their clean counterparts. The surface areas for the contaminated MS samples increased toward their clean-MS values during the 700-h aging period, but achieved the clean values only after pentane extraction or heating at 60 degrees C. Heating at 50 degrees C failed to achieve a similar recovery of the clean-MS surface area value. Nonspecific mass loss tracked the increase in surface area as indirect evidence that naphthalene loss was the cause of the surface area increase. For the LB samples, aging at 100 degrees C produced a slight decrease in surface area and mass while aging at 250 degrees C caused the surface area to increase roughly threefold while the mass decreased by approximately 1%. These results suggest that, under moderate heating and over the time scale of this investigation, there is a redistribution of the complex contaminant mixture on the solid matrix. Greater temperatures remove mass more efficiently and therefore exhibited the surface area increase expected in this experiment.

  3. X-Linked ocular albinism; Nettleship-Falls ocular albinism.

    PubMed

    Booth, Alexandria V; Soldano, Anthony C; Levine, Jonathan; Pomeranz, Miriam

    2008-05-15

    A 39-year-old man with foveal hypoplasia, nystagmus, and decreased visual acuity was found to have multiple, cutaneous, hypopigmented macules. Macromelanosomes were demonstrated in normal skin on histopathologic examination. The patient's constellation of findings along with a strong X-linked inheritance pattern in family members led to the diagnosis of X-linked ocular albinism, which is an uncommon condition that is characterized by congenital nystagmus, iris translucency, hypopigmentation of the ocular fundus, strabismus, foveal hypoplasia, photophobia, and impaired vision.

  4. 30 CFR 921.764 - Process for designating areas unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... surface coal mining operations. 921.764 Section 921.764 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PROGRAMS FOR THE CONDUCT OF SURFACE MINING OPERATIONS... mining operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for...

  5. High surface area silicon materials: fundamentals and new technology.

    PubMed

    Buriak, Jillian M

    2006-01-15

    Crystalline silicon forms the basis of just about all computing technologies on the planet, in the form of microelectronics. An enormous amount of research infrastructure and knowledge has been developed over the past half-century to construct complex functional microelectronic structures in silicon. As a result, it is highly probable that silicon will remain central to computing and related technologies as a platform for integration of, for instance, molecular electronics, sensing elements and micro- and nanoelectromechanical systems. Porous nanocrystalline silicon is a fascinating variant of the same single crystal silicon wafers used to make computer chips. Its synthesis, a straightforward electrochemical, chemical or photochemical etch, is compatible with existing silicon-based fabrication techniques. Porous silicon literally adds an entirely new dimension to the realm of silicon-based technologies as it has a complex, three-dimensional architecture made up of silicon nanoparticles, nanowires, and channel structures. The intrinsic material is photoluminescent at room temperature in the visible region due to quantum confinement effects, and thus provides an optical element to electronic applications. Our group has been developing new organic surface reactions on porous and nanocrystalline silicon to tailor it for a myriad of applications, including molecular electronics and sensing. Integration of organic and biological molecules with porous silicon is critical to harness the properties of this material. The construction and use of complex, hierarchical molecular synthetic strategies on porous silicon will be described.

  6. Surface Area, and Oxidation Effects on Nitridation Kinetics of Silicon Powder Compacts

    NASA Technical Reports Server (NTRS)

    Bhatt, R. T.; Palczer, A. R.

    1998-01-01

    Commercially available silicon powders were wet-attrition-milled from 2 to 48 hr to achieve surface areas (SA's) ranging from 1.3 to 70 sq m/g. The surface area effects on the nitridation kinetics of silicon powder compacts were determined at 1250 or 1350 C for 4 hr. In addition, the influence of nitridation environment, and preoxidation on nitridation kinetics of a silicon powder of high surface area (approximately equals 63 sq m/g) was investigated. As the surface area increased, so did the percentage nitridation after 4 hr in N2 at 1250 or 1350 C. Silicon powders of high surface area (greater than 40 sq m/g) can be nitrided to greater than 70% at 1250 C in 4 hr. The nitridation kinetics of the high-surface-area powder compacts were significantly delayed by preoxidation treatment. Conversely, the nitridation environment had no significant influence on the nitridation kinetics of the same powder. Impurities present in the starting powder, and those accumulated during attrition milling, appeared to react with the silica layer on the surface of silicon particles to form a molten silicate layer, which provided a path for rapid diffusion of nitrogen and enhanced the nitridation kinetics of high surface area silicon powder.

  7. New surgical approach in cases of cataract with ocular Stevens-Johnson syndrome.

    PubMed

    Sharma, Namrata; Aron, Neelima; Venugopal, Renu; Sangwan, Sushil; Titiyal, Jeewan Singh; Agarwal, Tushar

    2016-11-01

    We describe the intraoperative difficulties encountered in cases of ocular Stevens-Johnson syndrome as a result of a poor ocular surface, the presence of symblepharon, and varying degrees of corneal opacity with secondary poor visibility of anterior segment structures. Modifications to the standard phacoemulsification technique enabled safe and successful completion of the surgery in these cases.

  8. Ocular tropism of respiratory viruses.

    PubMed

    Belser, Jessica A; Rota, Paul A; Tumpey, Terrence M

    2013-03-01

    Respiratory viruses (including adenovirus, influenza virus, respiratory syncytial virus, coronavirus, and rhinovirus) cause a broad spectrum of disease in humans, ranging from mild influenza-like symptoms to acute respiratory failure. While species D adenoviruses and subtype H7 influenza viruses are known to possess an ocular tropism, documented human ocular disease has been reported following infection with all principal respiratory viruses. In this review, we describe the anatomical proximity and cellular receptor distribution between ocular and respiratory tissues. All major respiratory viruses and their association with human ocular disease are discussed. Research utilizing in vitro and in vivo models to study the ability of respiratory viruses to use the eye as a portal of entry as well as a primary site of virus replication is highlighted. Identification of shared receptor-binding preferences, host responses, and laboratory modeling protocols among these viruses provides a needed bridge between clinical and laboratory studies of virus tropism.

  9. Development of cortical thickness and surface area in autism spectrum disorder.

    PubMed

    Mensen, Vincent T; Wierenga, Lara M; van Dijk, Sarai; Rijks, Yvonne; Oranje, Bob; Mandl, René C W; Durston, Sarah

    2017-01-01

    Autism spectrum disorder (ASD) is a neurodevelopmental disorder often associated with changes in cortical volume. The constituents of cortical volume - cortical thickness and surface area - have separable developmental trajectories and are related to different neurobiological processes. However, little is known about the developmental trajectories of cortical thickness and surface area in ASD. In this magnetic resonance imaging (MRI) study, we used an accelerated longitudinal design to investigate the cortical development in 90 individuals with ASD and 90 typically developing controls, aged 9 to 20 years. We quantified cortical measures using the FreeSurfer software package, and then used linear mixed model analyses to estimate the developmental trajectories for each cortical measure. Our primary finding was that the development of surface area follows a linear trajectory in ASD that differs from typically developing controls. In typical development, we found a decline in cortical surface area between the ages of 9 and 20 that was absent in ASD. We found this pattern in all regions where developmental trajectories for surface area differed between groups. When we applied a more stringent correction that takes the interdependency of measures into account, this effect on cortical surface area retained significance for left banks of superior temporal sulcus, postcentral area, and right supramarginal area. These areas have previously been implicated in ASD and are involved in the interpretation and processing of audiovisual social stimuli and distinction between self and others. Although some differences in cortical volume and thickness were found, none survived the more stringent correction for multiple testing. This study underscores the importance of distinguishing between cortical surface area and thickness in investigating cortical development, and suggests the development of cortical surface area is of importance to ASD.

  10. [Ocular changes in dialysis patients].

    PubMed

    Popa, M; Nicoară, S

    2000-01-01

    The study analyzes the ocular aspects in patients receiving hemodialysis, in order to define the importance of the ophthalmological exam as prognosis and follow-up parameter. The prospective study includes 84 patients with renal insufficiency who received hemodialysis between 1994-1998. The ocular aspects and their connection with the dialysis and the basic disease are described and analyzed. The most important were the retinal vascular complications: hypertensive retinopathy, anterior optic ischaemic neuropathy, central retinal artery occlusion, diabetic retinopathy.

  11. Novel computer program for fast exact calculation of accessible and molecular surface areas and average surface curvature.

    PubMed

    Tsodikov, Oleg V; Record, M Thomas; Sergeev, Yuri V

    2002-04-30

    New computer programs, SurfRace and FastSurf, perform fast calculations of the solvent accessible and molecular (solvent excluded) surface areas of macromolecules. Program SurfRace also calculates the areas of cavities inaccessible from the outside. We introduce the definition of average curvature of molecular surface and calculate average molecular surface curvatures for each atom in a structure. All surface area and curvature calculations are analytic and therefore yield exact values of these quantities. High calculation speed of this software is achieved primarily by avoiding computationally expensive mathematical procedures wherever possible and by efficient handling of surface data structures. The programs are written initially in the language C for PCs running Windows 2000/98/NT, but their code is portable to other platforms with only minor changes in input-output procedures. The algorithm is robust and does not ignore either multiplicity or degeneracy of atomic overlaps. Fast, memory-efficient and robust execution make this software attractive for applications both in computationally expensive energy minimization algorithms, such as docking or molecular dynamics simulations, and in stand-alone surface area and curvature calculations.

  12. Measuring and comparing brain cortical surface area and other areal quantities

    PubMed Central

    Winkler, Anderson M.; Sabuncu, Mert R.; Yeo, B.T. Thomas; Fischl, Bruce; Greve, Douglas N.; Kochunov, Peter; Nichols, Thomas E.; Blangero, John; Glahn, David C.

    2012-01-01

    Structural analysis of MRI data on the cortical surface usually focuses on cortical thickness. Cortical surface area, when considered, has been measured only over gross regions or approached indirectly via comparisons with a standard brain. Here we demonstrate that direct measurement and comparison of the surface area of the cerebral cortex at a fine scale is possible using mass conservative interpolation methods. We present a framework for analyses of the cortical surface area, as well as for any other measurement distributed across the cortex that is areal by nature. The method consists of the construction of a mesh representation of the ortex, registration to a common coordinate system and, crucially, interpolation using a pycnophylactic method. Statistical analysis of surface area is done with power-transformed data to address lognormality, and inference is done with permutation methods. We introduce the concept of facewise analysis, discuss its interpretation and potential applications. PMID:22446492

  13. A route to high surface area, porosity and inclusion of large molecules in crystals.

    PubMed

    Chae, Hee K; Siberio-Pérez, Diana Y; Kim, Jaheon; Go, YongBok; Eddaoudi, Mohamed; Matzger, Adam J; O'Keeffe, Michael; Yaghi, Omar M

    2004-02-05

    One of the outstanding challenges in the field of porous materials is the design and synthesis of chemical structures with exceptionally high surface areas. Such materials are of critical importance to many applications involving catalysis, separation and gas storage. The claim for the highest surface area of a disordered structure is for carbon, at 2,030 m2 g(-1) (ref. 2). Until recently, the largest surface area of an ordered structure was that of zeolite Y, recorded at 904 m2 g(-1) (ref. 3). But with the introduction of metal-organic framework materials, this has been exceeded, with values up to 3,000 m2 g(-1) (refs 4-7). Despite this, no method of determining the upper limit in surface area for a material has yet been found. Here we present a general strategy that has allowed us to realize a structure having by far the highest surface area reported to date. We report the design, synthesis and properties of crystalline Zn4O(1,3,5-benzenetribenzoate)2, a new metal-organic framework with a surface area estimated at 4,500 m2 g(-1). This framework, which we name MOF-177, combines this exceptional level of surface area with an ordered structure that has extra-large pores capable of binding polycyclic organic guest molecules--attributes not previously combined in one material.

  14. Specific surface area of a crushed welded tuff before and after aqueous dissolution

    USGS Publications Warehouse

    Reddy, M.M.; Claassen, H.C.

    1994-01-01

    Specific surface areas were measured for several reference minerals (anorthoclase, labradorite and augite), welded tuff and stream sediments from Snowshoe Mountain, near Creede, Colorado. Crushed and sieved tuff had an unexpectedly small variation in specific surface area over a range of size fractions. Replicate surface area measurements of the largest and smallest tuff particle size fractions examined (1-0.3 mm and <0.212 mm) were 2.3 ?? 0.2 m2/g for each size fraction. Reference minerals prepared in the same way as the tuff had smaller specific surface areas than that of the tuff of the same size fraction. Higher than expected tuff specific surface areas appear to be due to porous matrix. Tuff, reacted in solutions with pH values from 2 to 6, had little change in specific surface area in comparison with unreacted tuff. Tuff, reacted with solutions having high acid concentrations (0.1 M hydrochloric acid or sulfuric-hydrofluoric acid), exhibited a marked increase in specific surface area compared to unreacted tuff. ?? 1994.

  15. Comparison of methods for measuring surface area of submersed aquatic macrophytes

    USGS Publications Warehouse

    Brown, Charles L.; Manny, Bruce A.

    1985-01-01

    The surface area of submersed macrophytes is often viewed from different perspectives such as substrate for colonization by periphyton, or protective cover for fishes. Consequently, several different methods have been used to measure it. We describe a method for measuring that area with an electronic surface area meter, a device that yields, for large samples of macrophytes, measurements in units of square meters of plant surface area per square meter of bottom. Unpreserved macrophytes, pressed gently between plastic sheets, are passed through the sensing head of the meter, which electronically scans and measures their surface area. The technique is several times faster and more precise than previous methods even for plants with finely dissected leaves.

  16. Surface areas and porosities of ices used to simulate stratospheric clouds

    NASA Technical Reports Server (NTRS)

    Keyser, Leon F.; Leu, Ming-Taun

    1993-01-01

    Surface areas, bulk densities, and porosities of ices formed at 85 or 200 K are measured to study the morphology of the vapor-deposited ices that have been used to simulate ice clouds in the laboratory. Surface areas are measured from the Brunauer, Emmett, and Teller (BET) analysis of absorption isotherms obtained at 72.2 K. Bulk densities and porosities are determined photogrammetrically. Results show that water ice and HNO3-H2O ice films deposited from the vapor at temperatures below 200 K exhibit large BET surface areas and are highly porous. For the ices annealed at temperatures above 200 K, external surface areas calculated from the observed particle sizes agree reasonably well with the BET areas, which indicates that the annealed ices are composed of nonporous particles and that the porosity of these ices is due to interstices among the particles.

  17. Automated detection of ocular focus.

    PubMed

    Hunter, David G; Nusz, Kevin J; Gandhi, Nainesh K; Quraishi, Imran H; Gramatikov, Boris I; Guyton, David L

    2004-01-01

    We characterize objectively the state of focus of the human eye, utilizing a bull's eye photodetector to detect the double-pass blur produced from a point source of light. A point fixation source of light illuminates the eye. Fundus-reflected light is focused by the optical system of the eye onto a bull's eye photodetector [consisting of an annulus (A) and a center (C) of approximately equal active area]. To generate focus curves, C/A is measured with a range of trial lenses in the light path. Three human eyes and a model eye are studied. In the model eye, the focus curve showed a sharp peak with a full width at half maximum (FWHM) of +/-0.25 D. In human eyes, the ratio C/A was >4 at best focus in all cases, with a FWHM of +/-1 D. The optical apparatus detects ocular focus (as opposed to refractive error) in real time. A device that can assess focus rapidly and objectively will make it possible to perform low-cost, mass screening for focusing problems such as may exist in children at risk for amblyopia.

  18. New observations on ocular onchocerciasis

    PubMed Central

    Rodger, F. C.

    1957-01-01

    The records of 2000 blind or partially blind persons in the onchocerciasis areas of West Africa provided the background information for this report. The author has grouped his material in three sections. The first of these deals with diagnostic methods, and contains the results of skin and conjunctival biopsies, as well as a description of onchocercomas and an estimate of the life-span of Onchocerca adults. Next, the pathogenesis of ocular lesions is discussed in the light of evidence obtained from a series of animal experiments designed to test two theories—namely, the existence of an allergic state and damage by toxins. In the last section, which is devoted to clinical observations, the author demonstrates the existence of a relationship between the posterior segmental lesion and vitamin A deficiency, and shows that punctate corneal opacities result more often from certain virus diseases and malaria than from onchocerciasis. A description follows of various degenerations due to a local nutritional disorder combined with vitamin A deficiency in onchocercal limbitis and anterior uveitis. PMID:13472406

  19. Cockpit Ocular Recording System (CORS)

    NASA Technical Reports Server (NTRS)

    Rothenheber, Edward; Stokes, James; Lagrossa, Charles; Arnold, William; Dick, A. O.

    1990-01-01

    The overall goal was the development of a Cockpit Ocular Recording System (CORS). Four tasks were used: (1) the development of the system; (2) the experimentation and improvement of the system; (3) demonstrations of the working system; and (4) system documentation. Overall, the prototype represents a workable and flexibly designed CORS system. For the most part, the hardware use for the prototype system is off-the-shelf. All of the following software was developed specifically: (1) setup software that the user specifies the cockpit configuration and identifies possible areas in which the pilot will look; (2) sensing software which integrates the 60 Hz data from the oculometer and heat orientation sensing unit; (3) processing software which applies a spatiotemporal filter to the lookpoint data to determine fixation/dwell positions; (4) data recording output routines; and (5) playback software which allows the user to retrieve and analyze the data. Several experiments were performed to verify the system accuracy and quantify system deficiencies. These tests resulted in recommendations for any future system that might be constructed.

  20. Ocular toxicity of targeted therapies.

    PubMed

    Renouf, Daniel J; Velazquez-Martin, Juan P; Simpson, Rand; Siu, Lillian L; Bedard, Philippe L

    2012-09-10

    Molecularly targeted agents are commonly used in oncology practice, and many new targeted agents are currently being tested in clinical trials. Although these agents are thought to be more specific and less toxic then traditional cytotoxic chemotherapy, they are associated with a variety of toxicities, including ocular toxicity. Many of the molecules targeted by anticancer agents are also expressed in ocular tissues. We reviewed the literature for described ocular toxicities associated with both approved and investigational molecularly targeted agents. Ocular toxicity has been described with numerous approved targeted agents and also seems to be associated with several classes of agents currently being tested in early-phase clinical trials. We discuss the proposed pathogenesis, monitoring guidelines, and management recommendations. It is important for oncologists to be aware of the potential for ocular toxicity, with prompt recognition of symptoms that require referral to an ophthalmologist. Ongoing collaboration between oncologists and ocular disease specialists is critical as the use of molecularly targeted agents continues to expand and novel targeted drug combinations are developed.

  1. Engineering and characterization of high surface area graphitic carbon nitrides for hydrogen sorption

    NASA Astrophysics Data System (ADS)

    Stalla, David; Seydel, Florian; Gillespie, Andrew; Lam, Thomas; Sweany, Mark; Lee, Mark; Pfeifer, Peter

    Theoretical calculations predict graphitic carbon nitride to produce a binding energy to hydrogen (6.4 kJ/mol) which is greater than that of pure graphene, making it attractive as a storage medium. However, the prohibitively small surface areas characteristic of g-CN materials dramatically limit H2 uptake. We discuss efforts to increase surface areas through physical/chemical exfoliation and templating. N2 sorption directly determines improvements to surface area, EF/TEM maps the thickness of aggregated planes, powder XRD indicates a novel, 2-phase structure, and XPS quantifies in-plane chemistry largely independent of the literature, which fails in a consensus regarding binding energy assignments.

  2. Assessment of heavy metal levels in surface sediments of estuaries and adjacent coastal areas in China

    NASA Astrophysics Data System (ADS)

    Liu, Xianbin; Li, Deliang; Song, Guisheng

    2017-03-01

    This article investigates the variations of contamination levels of heavy metals such as copper, lead, chromium, cadmium, zinc, arsenic, and mercury over time in surface sediments of the Changjiang River Estuary (CRE), Yellow River Estuary (YRE), Pearl River Estuary (PRE), and their adjacent coastal areas in China. The contamination factor (CF), pollution load index (PLI), and geoaccumulation index ( I geo) are used to evaluate the quality of the surface sediments in the study areas. The results showed that the CRE, YRE, and their adjacent coastal areas were at a low risk of contamination in terms of heavy metals, while the PRE and its adjacent coastal area were at a moderate level. By comparison, the concentrations of heavy metals in the surface sediments of the YRE and its adjacent coastal area were relatively lower than those in the CRE, PRE, and their adjacent coastal areas.

  3. Assessment of heavy metal levels in surface sediments of estuaries and adjacent coastal areas in China

    NASA Astrophysics Data System (ADS)

    Liu, Xianbin; Li, Deliang; Song, Guisheng

    2016-05-01

    This article investigates the variations of contamination levels of heavy metals such as copper, lead, chromium, cadmium, zinc, arsenic, and mercury over time in surface sediments of the Changjiang River Estuary (CRE), Yellow River Estuary (YRE), Pearl River Estuary (PRE), and their adjacent coastal areas in China. The contamination factor (CF), pollution load index (PLI), and geoaccumulation index (I geo) are used to evaluate the quality of the surface sediments in the study areas. The results showed that the CRE, YRE, and their adjacent coastal areas were at a low risk of contamination in terms of heavy metals, while the PRE and its adjacent coastal area were at a moderate level. By comparison, the concentrations of heavy metals in the surface sediments of the YRE and its adjacent coastal area were relatively lower than those in the CRE, PRE, and their adjacent coastal areas.

  4. Ocular Adverse Events Associated with Antibody–Drug Conjugates in Human Clinical Trials

    PubMed Central

    Miller, Paul E.; Mannis, Mark J.

    2015-01-01

    Abstract This article reviews ocular adverse events (AEs) reported in association with administration of antibody–drug conjugates (ADCs) in human clinical trials. References reporting ocular toxicity or AEs associated with ADCs were collected using online publication searches. Articles, abstracts, or citations were included if they cited ocular toxicities or vision-impairing AEs with a confirmed or suspected association with ADC administration. Twenty-two references were found citing ocular or vision-impairing AEs in association with ADC administration. All references reported use of ADCs in human clinical trials for treatment of various malignancies. The molecular target and cytotoxic agent varied depending on the ADC used. Ocular AEs affected a diversity of ocular tissues. The most commonly reported AEs involved the ocular surface and included blurred vision, dry eye, and corneal abnormalities (including microcystic corneal disease). Most ocular AEs were not severe (≤ grade 2) or dose limiting. Clinical outcomes were not consistently reported, but when specified, most AEs improved or resolved with cessation of treatment or with ameliorative therapy. A diverse range of ocular AEs are reported in association with administration of ADCs for the treatment of cancer. The toxicologic mechanism(s) and pathogenesis of such events are not well understood, but most are mild in severity and reversible. Drug development and medical professionals should be aware of the clinical features of these events to facilitate early recognition and intervention in the assessment of preclinical development programs and in human clinical trials. PMID:26539624

  5. Human ocular biometry☆

    PubMed Central

    Augusteyn, Robert C.; Nankivil, Derek; Mohamed, Ashik; Maceo, Bianca; Pierre, Faradia; Parel, Jean-Marie

    2012-01-01

    The aim of this study was to examine growth of the human eye globe and cornea from early in gestation to late in adult life. Globe antero-posterior length, horizontal and vertical diameters, corneal horizontal and vertical (white to white) diameters and posterior pole to limbus distances were measured using digital calipers (±0.01 mm) in 541 postmortem eyes. Additional pre- and postnatal data for some of the dimensions were obtained from the literature. All dimensions examined increase rapidly during prenatal development but postnatal growth differs. Growth of globe antero-posterior length, vertical and horizontal diameters as well as corneal vertical and horizontal diameters stops within 1 year after birth. Logistic analysis is consistent with an asymptotic prenatal growth mode and no further growth after its completion around 1 year after birth. Horizontal and vertical globe diameters are the same at all ages but the corneal horizontal diameter is always larger than the vertical diameter. No differences could be detected between males and females in any of the ocular dimensions. Globe and corneal growth take place primarily during the prenatal growth mode and dimensions reach their maxima, shortly after birth. It is suggested that cessation of a growth stimulating signal at birth marks the end of the prenatal growth mode and that the small increases over the next year are due to cells already stimulated. Male and female eyes of the same age have the same globe and cornea dimensions. PMID:22819768

  6. Rabies: ocular pathology.

    PubMed Central

    Haltia, M; Tarkkanen, A; Kivelä, T

    1989-01-01

    Ocular pathology in the first European case of human bat-borne rabies is described. The patient was a 30-year-old bat scientist who seven weeks after bat bite developed neurological symptoms and died 23 days later. Rabies virus antigens were detected in brain smears. After extensive virological studies the virus turned out to be a rabies-related virus, closely resembling the Duvenhage virus isolated from bats in South Africa in 1980. By light microscopy focal chronic inflammatory infiltration of the ciliary body and of the choroid was found. PAS-positive exudate was seen in the subretinal and in the outer plexiform layers of the retina, and retinal veins showed endothelial damage and perivascular inflammation. Many of the retinal ganglion cells were destroyed. The presence of rabies-related viral antigen in the retinal ganglion cells was shown by positive cytoplasmic immunofluorescence, though electron microscopy failed to identify definite viral structures in the retina. By immunohistochemistry glial fibrillary acidic protein was observed in the Müller's cells, which are normally negative for this antigen but express it as a reactive change when the retina is damaged. Synaptophysin, a constituent of presynaptic vesicles of normal retinal neurons, was not detected in the retina. Images PMID:2920157

  7. Managed Aquifer Recharge Systems - Recognition of the Importance of Travel Time Surface Area Relationships (Invited)

    NASA Astrophysics Data System (ADS)

    Fox, P.

    2013-12-01

    In Managed Aquifer Recharge (MAR) systems, sub-surface transport provides an environmental buffer for the removal of many constituents. There are many potential variables that may impact the removal of pathogens, organic carbon, constituents of emerging concern, and nitrogen during sub-surface transport. However, the mechanisms for the removal of these constituents are primarily dependent on surface mediated reactions during sub-surface transport. Microbial reactions with microbes attached to surfaces are associated with the majority of transformations. Microbial transformations are sustainable and have been demonstrated to sustain the removal of organic carbon, various constituents of emerging concern and nitrogen in indirect potable reuse systems. Evaluating all removal mechanisms during sub-surface transport for different classes of contaminants is extremely difficult. When the variables of water quality, redox conditions, aquifer matrix and temperature are all considered, the experimental matrix necessary for evaluation becomes impractical. Many results published in the literature considered to be site specific which limits their practical utility. Nevertheless, strong similarities in the performance of MAR systems with respect to the removal of a broad range of contaminants exist for systems in the United States, Europe and Israel. One hypothesis for the robustness of these systems is that when travel time criteria are applied to their design, the surface area contact during sub-surface transport is similar in most MAR systems. Since removal mechanisms during sub-surface transport are dependent on surface area, systems with similar amounts of surface area can provide similar levels of removal. Makam and Fox (2009) considered the relationship between surface area and travel time in aquifers commonly associated with the environmental buffers of indirect potable reuse systems. For a specific hydraulic gradient and travel time, the surface area in aquifers

  8. Covering all clinically significant areas of the colon surface in virtual colonoscopy

    NASA Astrophysics Data System (ADS)

    Kreeger, Kevin; Dachille, Frank; Wax, Mark R.; Kaufman, Arie E.

    2002-04-01

    We have developed a method that automatically displays, places in sized order and allows viewing of the areas of the colon surface not visualized during initial endoscopic navigational viewing. While complete surface visualization is possible, we demonstrate that all of these missed patches do not have to be reviewed to detect clinically significant colon polyps. CT scans are performed on 147 patients and volunteers after bowel preparation and colon distention with CO2. After automatic segmentation and electronic cleansing of the colon lumen, the medial axis (centerline) is extracted. Volume rendering fly-through along the centerline is performed and visualized surfaces are marked. To simulate optical colonoscopy, the virtual camera is passed in the antegrade direction. For virtual colonoscopy, the camera is passed both antegrade and retrograde, and the combined visible surface voxel count is recorded. After both fly-throughs, the total visualized surface is recorded and all 'patches' of connected surface area not yet seen are identified, measured, sorted by size, and counted. Clinically significant patches, defined as smallest diameter being > 5mm, are sequentially visualized by stepping through the sorted list until reaching the patch diameter of 5 mm.. for each. By enabling endoscopic navigation in both antegrade and retrograde directions, virtual colonoscopy is able to evaluate behind haustral folds and around sharp bends, thereby visualizing significantly more surface area than optical colonoscopy. Furthermore, automatic marking of the visualized surface area and identifying and viewing unseen patches allows examination of all clinically significant surfaces of the colon.

  9. Choroidal detachment and ocular hypotony: CT evaluation

    SciTech Connect

    Mafee, M.F.; Peyman, G.A.

    1984-12-01

    The computed tomographic (CT) findings in 20 patients with hemorrhagic choroidal detachment, serous choroidal detachment and/or ocular hypotony are described. Hemorrhagic choroidal detachment appeared as an area of high attenuation that was usually localized, uniformly hyperdense, and not position-dependent. Serous choroidal detachment appeared as a convex, thick line of increased density within the vitreous cavity. Inflammatory choroidal detachment produces a diffuse intrauveal and suprachoroidal accumulation of high-density, position-dependent fluid, and uveoscleral thickening and enhancement, which in cross section resembles a ring. CT has proved valuable in localizing and differentiating serous or hemorrhagic choroidal detachment and uveoscleral infolding.

  10. Surface Meteorology, Barrow, Alaska, Area A, B, C and D, Ongoing from 2012

    DOE Data Explorer

    Bob Busey; Larry Hinzman; William Cable; Vladimir Romanovsky

    2014-12-04

    Meteorological data are being collected at several points within four intensive study areas in Barrow. These data assist in the calculation of the energy balance at the land surface and are also useful as inputs into modeling activities.

  11. Synthesis and characterization of large specific surface area nanostructured amorphous silica materials.

    PubMed

    Marquez-Linares, Francisco; Roque-Malherbe, Rolando M A

    2006-04-01

    Large specific surface area materials attract wide attention because of their applications in adsorption, catalysis, and nanotechnology. In the present study, we describe the synthesis and characterization of nanostructured amorphous silica materials. These materials were obtained by means of a modification of the Stobe-Fink-Bohn (SFB) method. The morphology and essential features of the synthesized materials have been studied using an automated surface area and pore size analyzer and scanning electron microscopy. The existence of a micro/mesoporous structure in the obtained materials has been established. It was also found that the obtained particle packing materials show large specific surface area up to 1,600 m2/g. (To our best knowledge, there is no any reported amorphous silica material with such a higher specific surface area.) The obtained materials could be useful in the manufacture of adsorbents, catalyst supports, and other nanotechnological applications.

  12. Porous silicon structures with high surface area/specific pore size

    DOEpatents

    Northrup, M. Allen; Yu, Conrad M.; Raley, Norman F.

    1999-01-01

    Fabrication and use of porous silicon structures to increase surface area of heated reaction chambers, electrophoresis devices, and thermopneumatic sensor-actuators, chemical preconcentrates, and filtering or control flow devices. In particular, such high surface area or specific pore size porous silicon structures will be useful in significantly augmenting the adsorption, vaporization, desorption, condensation and flow of liquids and gasses in applications that use such processes on a miniature scale. Examples that will benefit from a high surface area, porous silicon structure include sample preconcentrators that are designed to adsorb and subsequently desorb specific chemical species from a sample background; chemical reaction chambers with enhanced surface reaction rates; and sensor-actuator chamber devices with increased pressure for thermopneumatic actuation of integrated membranes. Examples that benefit from specific pore sized porous silicon are chemical/biological filters and thermally-activated flow devices with active or adjacent surfaces such as electrodes or heaters.

  13. Porous silicon structures with high surface area/specific pore size

    DOEpatents

    Northrup, M.A.; Yu, C.M.; Raley, N.F.

    1999-03-16

    Fabrication and use of porous silicon structures to increase surface area of heated reaction chambers, electrophoresis devices, and thermopneumatic sensor-actuators, chemical preconcentrates, and filtering or control flow devices. In particular, such high surface area or specific pore size porous silicon structures will be useful in significantly augmenting the adsorption, vaporization, desorption, condensation and flow of liquids and gases in applications that use such processes on a miniature scale. Examples that will benefit from a high surface area, porous silicon structure include sample preconcentrators that are designed to adsorb and subsequently desorb specific chemical species from a sample background; chemical reaction chambers with enhanced surface reaction rates; and sensor-actuator chamber devices with increased pressure for thermopneumatic actuation of integrated membranes. Examples that benefit from specific pore sized porous silicon are chemical/biological filters and thermally-activated flow devices with active or adjacent surfaces such as electrodes or heaters. 9 figs.

  14. Geohydrology and susceptibility of major aquifers to surface contamination in Alabama, area 7

    USGS Publications Warehouse

    Mooty, W.S.

    1987-01-01

    The geohydrology and susceptibility of the seven major aquifers to surface contamination in Area 7 - Bibb, Dallas, Hale, Perry, and Wilcox Counties, are described. Aquifers in the northern part of the study area are in Paleozoic limestones and dolomite formations. Deposits in the central part of the study area are predominately of Cretaceous age and contain the Coker, Gordo, and Eutaw aquifers. Although the southern part of the study area has many deposits of Tertiary age, the Ripley Formation of Cretaceous age is the major aquifer. Contamination of any of the major aquifers is improbable because the majority of the recharge area for the primary aquifers is woodland, pasture, or farmland. Downdip from their outcrops, the major aquifers in the study area are protected from land surface contamination by relatively impermeable layers of clay and chalk. The aquifers that are highly susceptible to contamination are the ones in the limestone and dolomite formations in northern Bibb County. Sinkholes exist in the recharge area of these formations and could provide a direct link for contaminates from the land surface to the water table. An area northeast of the Selma well field is also highly susceptible to contamination. The Eutaw Formation in this area is overlain by alluvial deposits that could increase recharge to the aquifer by slowing the runoff rate of surface water. (USGS)

  15. Positive pressure ventilation during anesthesia in dogs: Assessment of surface area derived tidal volume.

    PubMed

    Dyson, Doris H

    2012-01-01

    The purpose of this study was to assess the use of surface area derived tidal volume in anesthetized ventilated dogs (n = 71, random assignment) compared to settings by experienced personnel. There was no significant difference (P = 0.1030) between methods (p(a)CO(2) of 43.1 ± 7 mmHg and 39.8 ± 7 mmHg, respectively). Surface area derived tidal volume can achieve satisfactory ventilation.

  16. Estimation of surface area concentration of workplace incidental nanoparticles based on number and mass concentrations

    NASA Astrophysics Data System (ADS)

    Park, J. Y.; Ramachandran, G.; Raynor, P. C.; Kim, S. W.

    2011-10-01

    Surface area was estimated by three different methods using number and/or mass concentrations obtained from either two or three instruments that are commonly used in the field. The estimated surface area concentrations were compared with reference surface area concentrations (SAREF) calculated from the particle size distributions obtained from a scanning mobility particle sizer and an optical particle counter (OPC). The first estimation method (SAPSD) used particle size distribution measured by a condensation particle counter (CPC) and an OPC. The second method (SAINV1) used an inversion routine based on PM1.0, PM2.5, and number concentrations to reconstruct assumed lognormal size distributions by minimizing the difference between measurements and calculated values. The third method (SAINV2) utilized a simpler inversion method that used PM1.0 and number concentrations to construct a lognormal size distribution with an assumed value of geometric standard deviation. All estimated surface area concentrations were calculated from the reconstructed size distributions. These methods were evaluated using particle measurements obtained in a restaurant, an aluminum die-casting factory, and a diesel engine laboratory. SAPSD was 0.7-1.8 times higher and SAINV1 and SAINV2 were 2.2-8 times higher than SAREF in the restaurant and diesel engine laboratory. In the die casting facility, all estimated surface area concentrations were lower than SAREF. However, the estimated surface area concentration using all three methods had qualitatively similar exposure trends and rankings to those using SAREF within a workplace. This study suggests that surface area concentration estimation based on particle size distribution (SAPSD) is a more accurate and convenient method to estimate surface area concentrations than estimation methods using inversion routines and may be feasible to use for classifying exposure groups and identifying exposure trends.

  17. Relationships among particle number, surface area, and respirable mass concentrations in automotive engine manufacturing.

    PubMed

    Heitbrink, William A; Evans, Douglas E; Ku, Bon Ki; Maynard, Andrew D; Slavin, Thomas J; Peters, Thomas M

    2009-01-01

    This study investigated the relationships between particle number, surface area, and respirable mass concentration measured simultaneously in a foundry and an automotive engine machining and assembly center. Aerosol concentrations were measured throughout each plant with a condensation particle counter for number concentration, a diffusion charger for active surface area concentration, and an optical particle counter for respirable mass concentration. At selected locations, particle size distributions were characterized with the optical particle counter and an electrical low pressure impactor. Statistical analyses showed that active surface area concentration was correlated with ultrafine particle number concentration and weakly correlated with respirable mass concentration. Correlation between number and active surface area concentration was stronger during winter (R2 = 0.6 for both plants) than in the summer (R2 = 0.38 and 0.36 for the foundry and engine plant respectively). The stronger correlation in winter was attributed to use of direct-fire gas fired heaters that produced substantial numbers of ultrafine particles with a modal diameter between 0.007 and 0.023 mu m. These correlations support findings obtained through theoretical analysis. Such analysis predicts that active surface area increasingly underestimates geometric surface area with increasing particle size, particularly for particles larger than 100 nm. Thus, a stronger correlation between particle number concentration and active surface area concentration is expected in the presence of high concentrations of ultrafine particles. In general, active surface area concentration may be a concentration metric that is distinct from particle number concentration and respirable mass concentration. For future health effects or toxicological studies involving nano-materials or ultrafine aerosols, this finding needs to be considered, as exposure metrics may influence data interpretation.

  18. Method of forming macro-structured high surface area transparent conductive oxide electrodes

    DOEpatents

    Forman, Arnold J.; Chen, Zhebo; Jaramillo, Thomas F.

    2016-01-05

    A method of forming a high surface area transparent conducting electrode is provided that includes depositing a transparent conducting thin film on a conductive substrate, where the transparent conducting thin film includes transparent conductive particles and a solution-based transparent conducting adhesive layer which serves to coat and bind together the transparent conducting particles, and heat treating the transparent conducting adhesion layer on the conductive substrate, where an increased surface area transparent conducting electrode is formed.

  19. The Area of a Surface Generated by Revolving a Graph about Any Line

    ERIC Educational Resources Information Center

    Goins, Edray Herber; Washington, Talitha M.

    2013-01-01

    We discuss a general formula for the area of the surface that is generated by a graph [t[subscript 0], t[subscript 1] [right arrow] [the set of real numbers][superscript 2] sending t [maps to] (x(t), y(t)) revolved around a general line L : Ax + By = C. As a corollary, we obtain a formula for the area of the surface formed by revolving y = f(x)…

  20. High-surface-area, dual-function oxygen electrocatalysts for space power applications

    NASA Technical Reports Server (NTRS)

    Ham, David O.; Moniz, Gary; Taylor, E. Jennings

    1987-01-01

    The processes of hydration/dehydration and carbonation/decarbonation are investigated as an approach to provide higher surface area mixed metal oxides that are more active electrochemically. These materials are candidates for use as electrocatalysts and electrocatalyst supports for alkaline electrolyzers and fuel cells. For the case of the perovskite, LaCoO3 , higher surface areas were achieved with no change in structure and a more active oxygen electrocatalyst.