1,085 research outputs found
Pseudophakic cystoid macular edema: update 2016
No full textAndrzej Grzybowski,1,2 Bartosz L Sikorski,3 Francisco J Ascaso,4,5 Valentín Huerva6,7 1Department of Ophthalmology, University of Warmia and Mazury, Olsztyn, Poland; 2Department of Ophthalmology, Poznan City Hospital, Poznan, Poland; 3Department of Ophthalmology, Nicolaus Copernicus University, Bydgoszcz, Poland; 4Department of Ophthalmology, Hospital Clínico Universitario “Lozano Blesa”, Zaragoza, Spain; 5Instituto de Investigación Sanitaria Aragón (IIS Aragón), Zaragoza, Spain; 6Department of Ophthalmology, Universitary Hospital Arnau de Vilanova, Lleida, Spain; 7IRB Lleida, Lleida, Spain Abstract: Pseudophakic cystoid macular edema (PCME) is the most common complication of cataract surgery, leading in some cases to a decrease in vision. Although the pathogenesis of PCME is not completely understood, the contribution of postsurgical inflammation is generally accepted. Consequently, anti-inflammatory medicines, including steroids and nonsteroidal anti-inflammatory drugs, have been postulated as having a role in both the prophylaxis and treatment of PCME. However, the lack of a uniformly accepted PCME definition, conflicting data on some risk factors, and the scarcity of studies comparing the role of nonsteroidal anti-inflammatory drugs to steroids in PCME prevention make the problem of PCME one of the puzzles of ophthalmology. This paper presents an updated review on the pathogenesis, risk factors, and use of anti-inflammatory drugs in PCME that reflect current research and practice. Keywords: Pseudophakic cystoid macular edema, cataract surgery, cataract surgery complications, retina, post-operative complication
Hermenegildo Arruga (1886‐1972): an example that the improvement in retinal surgery goes on
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81 fJ/bit energy-to-data ratio of 850 nm vertical-cavity surface-emitting lasers for optical interconnects
No full textThis article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 98, 231106 (2011) and may be found at https://doi.org/10.1063/1.3597799.Extremely energy-efficient oxide-confined high-speed 850 nm vertical-cavity surface-emitting lasers for optical interconnects are presented. Error-free performance at 17 and 25 Gb/s via a 100 m multimode fiber link is demonstrated at record high dissipation-power-efficiencies of up to 69 fJ/bit (<0.1mW/Gbps) and 99 fJ/bit, respectively. These are the most power efficient high-speed directly modulated light sources reported to date. The total energy-to-data ratio is 83 fJ/bit at 25°C and reduces to 81 fJ/bit at 55°C. These results were obtained without adjustment of driving conditions. A high -factor of 12.0GHz/(mA)0.5 and a -factor of 0.41 ns are measured.EC/FP7/224211/EU/VISIT - Vertically Integrated Systems for Information Transfer/VISITDFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, Bauelement
Single-drive high-speed lumped depletion-type modulators toward 10 fJ/bit energy consumption
No full textReduction of modulator energy consumption to 10 fJ/bit is essential for the sustainable development of communication systems. Lumped modulators might be a viable solution if instructed by a complete theory system. Here, we present a complete analytical electro-optic response theory, energy consumption analysis, and eye diagrams on absolute scales for lumped modulators. Consequently the speed limitation is understood and alleviated by single-drive configuration, and comprehensive knowledge into the energy dependence on structural parameters significantly reduces energy consumption. The results show that silicon modulation energy as low as 80.8 and 21.5 fJ/bit can be achieved at 28 Gbd under 50 and 10 Omega impedance drivers, respectively. A 50 Gbd modulation is also shown to be possible. The analytical models can be extended to lumped modulators on other material platforms and offer a promising solution to the current challenges of modulation energy reduction. (C) 2017 Chinese Laser PressNational Natural Science Foundation of China (NSFC) [61120106012]SCI(E)ARTICLE2134-142
Valoración de la efectividad del tratamiento del síndrome de apnea-hipopnea del sueño (SAHS) a través del estudio de la retina mediante tomografía de coherencia óptica (OCT)
No full textEl síndrome de apnea-hipopnea del sueño (SAHS) es uno de los trastornos respiratorios del sueño más frecuentes en la población general, a pesar de estar infradiagnosticado. Sus graves secuelas y el elevado gasto sanitario que conlleva, hacen que sean necesarios buenos métodos de diagnóstico para un tratamiento precoz. La tomografía de coherencia óptica (OCT), prueba sencilla, incruenta, barata y accesible, es una de las técnicas que se han propuesto para el diagnóstico del SAHS. Múltiples publicaciones coinciden en que la OCT es capaz de demostrar afectación de la retina en estos pacientes. Nuestro estudio da un paso más y plantea la OCT como técnica de seguimiento tras el tratamiento del SAHS. En una muestra de 96 ojos de 52 pacientes, divididos según nivel de gravedad de SAHS y en función del tipo de tratamiento recibido (CPAP, cirugía o un tratamiento combinado), se ha hecho un seguimiento a 6 meses, comparando los parámetros maculares, de la capa de fibras nerviosas de la retina (CFNR) a nivel peripapilar y datos morfométricos de la cabeza del nervio óptico, medidos con OCT antes y después del tratamiento. Los SAHS leve-moderados, que presentaban a priori mayores espesores maculares y de la CFNR, presentaron una disminución estadísticamente significativa de estos parámetros tras el tratamiento, mientras que los SAHS graves, cuyos espesores estaban reducidos, presentaron un aumento estadísticamente significativo del grosor foveal y del espesor medio de la CFNR peripapilar. Dichos resultados son compatibles con la teoría de una posible inflamación retiniana en los SAHS leve-moderados y de un proceso de adelgazamiento o atrofia en los SAHS graves, que parece revertir tras el tratamiento, a pesar de que futuros estudios con muestras más amplias son necesarios para contrastar dichos resultados. Bibliografía: 1. Durán-cantolla J, Puertas-Cuesta FJ, Pin-Arboledas G, Santa María-Cano J y el Grupo Español de Sueño (GES). Documento de consenso nacional sobre el síndrome de apneas-hipopneas del sueño. Arch Bronconeumol 2005;41:1-110. 2. Montserrat JM, Hernández L, Nacher M, Barbé F. Nuevos aspectos patogénicos en el síndrome de apneas e hipopneas durante el sueño (SAHS). Arch Bronconeumol 2004;40:27-34. 3. Vicente E, Marin JM, Vicente P, Guallar M, Forner M. Consecuencias médicas del síndrome de apnea-hipopnea durante el sueño (SAHS). En: Plaza G, Baptista PM, O´Connor C. Trastornos respiratorios del sueño: actualización en diagnóstico y tratamiento quirúrgico. Barcelona:Indica;2015.p.103-22. 4. Sher EA, Schechtman KB, Piccirillo JF. The efficacy of surgical modifications of the upper airway in adults with obstructive sleep apnea syndrome. Sleep 1996;19:156-77. 5. Vicente E, Marín JM, Carrizo S, Naya MJ. Tongue-base suspension in conjunction with uvulopalatopharyngoplasty for treatment of severe obstructive sleep apnea: long-term follow-up results. Laryngoscope 2006;116:1223-7. 6. Marin JM, Carrizo SJ, Vicente E, Agusti AG. Long-term cardiovascular outcomes in men with obstructive sleep apnoea-hypopnoea with or without treatment with continuous positive airway pressure: an observational study. Lancet 2005;365:1046–53. 7. Lin PW, Friedman M, Lin HC, Chang HW, Pulver TM, Chin CH. Decreased retinal nerve fiber layer thickness in patients with obstructive sleep apnea/hypopnea syndrome. Graefes Arch Clin Exp Ophthalmol 2011;249:585-93. 8. Casas P, Ascaso FJ, Vicente E, Tejero-Garcés G, Adiego MI, Cristóbal JA. Retinal and optic nerve evaluation by optical coherence tomography in adults with obstructive sleep apnea-hypopnea syndrome (OSAHS). Graefes Arch Clin Exp Ophthalmol 2013;251:1625-1634. 9. Sagiv O, Fishelson-Arev T, Buckman G, Mathalone N, Wolfson J, Segev E, Peled R, Lavi I, Geyer O. Retinal nerve fiber layer thickness measurements by optical coherence tomography in patients with sleep apnea syndrome. Clin Experiment Ophthalmol 2014;42:132-8. 10. Zengin MO, Tuncer I, Karahan E. Retinal nerve fiber layer thickness changes in obstructive sleep apnea syndrome: one year follow-up results. Int J Ophthalmol 2014;7:704-8. 11. Kiekens S, De Groot V, Coeckelbergh T, Tassignon MJ, Van de Heyning P, De Backer W, Verbraecken J. Continuous positive airway pressure therapy is associated with an increase in intraocular pressure in obstructive sleep apnea. Invest Ophthalmol Vis Sci 2008;49:934-40. 12. Ascaso FJ, Rodriguez-Jiménez R, Cabezón L, López-Antón R, Santabárbara J, De la Cámara C, Modrego PJ, Quintanilla MA, Bagney A, Guitierrez L, Cruz N, Cristóbal JA, Lobo A. Retinal nerve fiber layer and macular thickness in patients with schizophrenia: influence of recent illness episodes. Psychiatry Res 2015;229:230-6
Author Arna Bontemps reads to children at the East Winston Branch Library, 1956.
No full textAuthor Arna Bontemps reads to children at the East Winston Branch Library, 1956
SPIN AND CHARGE FLUCTUATIONS IN ITINERANT-ELECTRON MAGNETISM - A VARIATIONAL FUNCTIONAL-INTEGRAL APPROXIMATION
No full textThe single-site spin-fluctuation theory of metallic magnetism developed by Hubbard and Hasegawa is modified and extended to investigate the effects of spin and charge fluctuations on the magnetic properties at finite temperature. The key point of our scheme is to adopt a continuous decomposition of the interacting part of the Hubbard Hamiltonian in the Stratonovich-Hubbard transformation, resulting in the separation of the charge fluctuations from the spin fluctuations. This separation makes a better description for the contrary nature between the two types of fluctuations. In order to remove the ambiguity, a variational principle is introduced to determine the appropriate form of the decomposition of the Hubbard model. The ground-state properties, the Curie temperature, the magnetization, and the paramagnetic susceptibility, etc., at finite temperature are calculated and compared with the Hasegawa theory. The improvement of the Curie temperature is significant, and better behavior of the temperature dependence of the magnetization is obtained.Physics, Condensed MatterSCI(E)6ARTICLE1712795-128044
Two-Photon AMPK and ATP Imaging Reveals Metabolic Recovery in Mouse Rod Photoreceptor Cells
No full textThe title of publisher's version: Two-photon AMPK and ATP imaging reveals the bias between rods and cones in glycolysis utility.In vertebrates, retinal rod and cone photoreceptor cells rely significantly on glycolysis. Lactate released from photoreceptor cells fuels neighboring retinal pigment epithelium cells and Müller glial cells through oxidative phosphorylation. To understand this highly heterogeneous metabolic environment around photoreceptor cells, single-cell analysis is needed. Here, we visualized cellular AMP-activated protein kinase (AMPK) activity and ATP levels in the retina by two-photon microscopy. Transgenic mice expressing a hyBRET-AMPK biosensor were used for measuring the AMPK activity. GO-ATeam2 transgenic mice were used for measuring the ATP level. Temporal metabolic responses were successfully detected in the live retinal explants upon drug perfusion. A glycolysis inhibitor, 2-deoxy-d-glucose (2-DG), activated AMPK and reduced ATP. These effects were clearly stronger in rods than in cones. Notably, rod AMPK and ATP started to recover at 30 min from the onset of 2-DG perfusion. Consistent with these findings, ex vivo electroretinogram recordings showed a transient slowdown in rod dim flash responses during a 60-min 2-DG perfusion, whereas cone responses were not affected. Based on these results, we propose that cones surrounded by highly glycolytic rods become less dependent on glycolysis, and rods also become less dependent on glycolysis within 60 min upon the glycolysis inhibition
A low noise, low power dynamic amplifier with common mode detect and a low power, low noise comparator for pipelined SAR-ADC
No full textThis thesis presents a high gain, low noise and low power dynamic residue amplifier and a low power, low noise dynamic comparator designed in TSMC 28nm process for a two step Pipelined SAR-ADC. The cascoded integrator dynamic residue amplifier (CIDRA) achieves a gain of 30dB with THD of 47dB (11 mV pp input). The input referred noise across tem- perature and process corner is 55 µV and it operates at a frequency of 500MHz while the energy consumption is 390 fJ. The low power and low noise pseudo-latch preamp dynamic comparator (PLPDC) shows a delay of 250pSec for a differential input of 16 pV and consumes 91 fJ (current is 91 µA for 100 MHz clock) of energy. The input referred offset is 4 mV (?).Microelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc
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