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https://www.readbyqxmd.com/read/28214102/vitreomacular-adhesion-and-the-risk-of-neovascular-age-related-macular-degeneration
#1
Emilia Maggio, Antonio Polito, Massimo Guerriero, Guido Prigione, Barbara Parolini, Grazia Pertile
PURPOSE: To assess the prevalence of vitreomacular adhesion (VMA) in consecutive naïve eyes diagnosed with exudative age-related macular degeneration (AMD) in comparison with eyes with nonexudative AMD and age-matched controls, and to evaluate prospectively the incidence of vitreomacular interface changes over time and their influence on choroidal neovascularization (CNV) development. DESIGN: Retrospective cross-sectional analysis and longitudinal cohort study conducted at Sacrocuore Hospital, Negrar, Verona, Italy...
February 14, 2017: Ophthalmology
https://www.readbyqxmd.com/read/28213258/p-aminothiophenol-coated-cdse-zns-quantum-dots-as-a-turn-on-fluorescent-probe-for-ph-detection-in-aqueous-media
#2
Dong Li, Hu Xu, Dan Li, Yuhong Wang
Since controlling hydrogen ion concentration (i.e. pH) is fairly important in various fields, developing a facile pH detection method is highly desired. Owing to the superior optical properties, semiconductor quantum dots (QDs) have been developed as a promising alternative for organic fluorophores in fluorescence analysis. In this study, a hydrophilic p-aminothiophenol (pATP) capped CdSe/ZnS QDs (denoted as pATP-QDs) as a selective "turn-on" fluorescence probe for pH in aqueous media is reported. The pATP-QDs probe easily obtained via ligand exchange are characterized by various analytic techniques including ultraviolet-visible, fourier transform infrared, fluorescence, time-resolved fluorescence spectroscopies, and transmission electron microscope etc...
May 1, 2017: Talanta
https://www.readbyqxmd.com/read/28212983/acircularity-index-and-axis-ratio-of-the-foveal-avascular-zone-in-diabetic-eyes-and-healthy-controls-measured-by-optical-coherence-tomography-angiography
#3
Brian D Krawitz, Shelley Mo, Lawrence S Geyman, Steven A Agemy, Nicole K Scripsema, Patricia M Garcia, Toco Y P Chui, Richard B Rosen
Given the complexity of the current system used to stage diabetic retinopathy (DR) and the risks and limitations associated with intravenous fluorescein angiography (IVFA), noninvasive quantification of DR severity is desirable. We examined the utility of acircularity index and axis ratio of the foveal avascular zone (FAZ), metrics that can noninvasively quantify the severity of diabetic retinopathy without the need for axial length to correct for individual retinal magnification. A retrospective review was performed of type 2 diabetics and age-matched controls imaged with optical coherence tomography angiography (OCTA)...
February 14, 2017: Vision Research
https://www.readbyqxmd.com/read/28211740/ultrafast-structure-switching-through-nonlinear-phononics
#4
D M Juraschek, M Fechner, N A Spaldin
We describe a mechanism by which nonlinear phononics allows ultrafast coherent and directional control of transient structural distortions. With ErFeO_{3} as a model system, we use density functional theory to calculate the structural properties as input into an anharmonic phonon model that describes the response of the system to a pulsed optical excitation. We find that the trilinear coupling of two orthogonal infrared-active phonons to a Raman-active phonon causes a transient distortion of the lattice. In contrast to the quadratic-linear coupling that has been previously explored, the direction of the distortion is determined by the polarization of the exciting light, introducing a novel mechanism for nonlinear phononic switching...
February 3, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28211526/stable-optical-trapping-and-sensitive-characterization-of-nanostructures-using-standing-wave-raman-tweezers
#5
Mu-Ying Wu, Dong-Xiong Ling, Lin Ling, William Li, Yong-Qing Li
Optical manipulation and label-free characterization of nanoscale structures open up new possibilities for assembly and control of nanodevices and biomolecules. Optical tweezers integrated with Raman spectroscopy allows analyzing a single trapped particle, but is generally less effective for individual nanoparticles. The main challenge is the weak gradient force on nanoparticles that is insufficient to overcome the destabilizing effect of scattering force and Brownian motion. Here, we present standing-wave Raman tweezers for stable trapping and sensitive characterization of single isolated nanostructures with a low laser power by combining a standing-wave optical trap with confocal Raman spectroscopy...
February 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28211261/early-microvascular-retinal-changes-in-optical-coherence-tomography-angiography-in-patients-with-type-1-diabetes-mellitus
#6
Joseph M Simonett, Fabio Scarinci, Fabiana Picconi, Paola Giorno, Daniele De Geronimo, Antonio Di Renzo, Monica Varano, Simona Frontoni, Mariacristina Parravano
PURPOSE: Diabetic retinopathy (DR) can lead to significant vision loss and blindness and has a particularly high prevalence in patients with type 1 diabetes (DM1). In this study, we investigate quantitative differences in optical coherence tomography angiography (OCTA) data between DM1 patients with no or mild signs of retinopathy and non-diabetic subjects. METHODS: Optical coherence tomography angiography (OCTA) imaging was performed on DM1 patients with no or mild nonproliferative diabetic retinopathy and healthy, age-matched controls...
February 16, 2017: Acta Ophthalmologica
https://www.readbyqxmd.com/read/28210908/updates-in-outcomes-of-stereotactic-radiation-therapy-in-acromegaly
#7
REVIEW
Monica Livia Gheorghiu
Purpose Treatment of acromegaly has undergone important progress in the last 20 years mainly due to the development of new medical options and advances in surgical techniques. Pituitary surgery is usually first-line therapy, and medical treatment is indicated for persistent disease, while radiation (RT) is often used as third-line therapy. The benefits of RT (tumor volume control and decreased hormonal secretion) are hampered by the long latency of the effect and the high risk of adverse effects. Stereotactic RT methods have been developed with the aim to provide more precise targeting of the tumor with better control of the radiation dose received by the adjacent brain structures...
February 16, 2017: Pituitary
https://www.readbyqxmd.com/read/28209502/detailed-phenotyping-and-characterization-of-choroidal-morphological-and-vascular-features-in-young-men-with-high-myopia-using-spectral-domain-optical-coherence-tomography
#8
Preeti Gupta, Sri Gowtham Thakku, Seang-Mei Saw, Mellisa Tan, Edmund Lim, Marcus Tan, Chui Ming Gemmy Cheung, Tien-Yin Wong, Ching-Yu Cheng
PURPOSE: To describe detailed morphological and vascular features of the choroid in eyes with high myopia. DESIGN: Cross-sectional study. METHODS: 515 eyes of young men (mean age 21.59±1.15) years) with high myopia (defined as -6.0 D or worse, mean spherical equivalent -8.66±2.00 D) and 88 controls with emmetropia in both eyes underwent choroidal imaging using spectral domain optical coherence tomography with enhanced depth imaging (EDI-OCT)...
February 13, 2017: American Journal of Ophthalmology
https://www.readbyqxmd.com/read/28208393/nonvariational-mechanism-of-front-propagation-theory-and-experiments
#9
A J Alvarez-Socorro, M G Clerc, G González-Cortés, M Wilson
Multistable systems exhibit a rich front dynamics between equilibria. In one-dimensional scalar gradient systems, the spread of the fronts is proportional to the energy difference between equilibria. Fronts spreading proportionally to the energetic difference between equilibria is a characteristic of one-dimensional scalar gradient systems. Based on a simple nonvariational bistable model, we show analytically and numerically that the direction and speed of front propagation is led by nonvariational dynamics...
January 2017: Physical Review. E
https://www.readbyqxmd.com/read/28208328/self-similar-asymptotic-optical-beams-in-semiconductor-waveguides-doped-with-quantum-dots
#10
Jun-Rong He, Lin Yi, Hua-Mei Li
The self-similar propagation of asymptotic optical beams in semiconductor waveguides doped with quantum dots is reported. The possibility of controlling the shape of output asymptotic optical beams is demonstrated. The analytical results are confirmed by numerical simulations. We give a possible experimental protocol to generate the obtained asymptotic parabolic beams in realistic waveguides. As a generalization to the present work, the self-similar propagation of asymptotic optical beams is proposed in a power-law nonlinear medium...
January 2017: Physical Review. E
https://www.readbyqxmd.com/read/28208185/evaluation-of-progressive-visual-dysfunction-and-retinal-degeneration-in-patients-with-parkinson-s-disease
#11
Maria Satue, Maria J Rodrigo, Javier Obis, Elisa Vilades, Hector Gracia, Sofia Otin, Maria I Fuertes, Raquel Alarcia, Jose A Crespo, Vicente Polo, Jose M Larrosa, Luis E Pablo, Elena Garcia-Martin
Purpose: To quantify changes in visual function parameters and in the retinal nerve fiber layer and macular thickness over a 5-year period in patients with Parkinson's disease (PD). Methods: Thirty patients with PD and 30 healthy subjects underwent a complete ophthalmic evaluation, including assessment of visual acuity, contrast sensitivity vision, color vision, and retinal evaluation with spectral-domain optical coherence tomography (SD-OCT). All subjects were reevaluated after 5 years to quantify changes in visual function parameters, the retinal nerve fiber layer, and macular thickness...
February 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28206829/validity-of-low-contrast-letter-acuity-as-a-visual-performance-outcome-measure-for-multiple-sclerosis
#12
Laura J Balcer, Jenelle Raynowska, Rachel Nolan, Steven L Galetta, Raju Kapoor, Ralph Benedict, Glenn Phillips, Nicholas LaRocca, Lynn Hudson, Richard Rudick
Low-contrast letter acuity (LCLA) has emerged as the leading outcome measure to assess visual disability in multiple sclerosis (MS) research. As visual dysfunction is one of the most common manifestations of MS, sensitive visual outcome measures are important in examining the effect of treatment. Low-contrast acuity captures visual loss not seen in high-contrast visual acuity (HCVA) measurements. These issues are addressed by the MS Outcome Assessments Consortium (MSOAC), including representatives from advocacy organizations, Food and Drug Administration (FDA), European Medicines Agency (EMA), National Institute of Neurological Disorders and Stroke (NINDS), academic institutions, and industry partners along with persons living with MS...
February 1, 2017: Multiple Sclerosis: Clinical and Laboratory Research
https://www.readbyqxmd.com/read/28205643/optical-switching-using-transition-from-dipolar-to-charge-transfer-plasmon-modes-in-ge2sb2te5-bridged-metallodielectric-dimers
#13
Arash Ahmadivand, Burak Gerislioglu, Raju Sinha, Mustafa Karabiyik, Nezih Pala
Capacitive coupling and direct shuttling of charges in nanoscale plasmonic components across a dielectric spacer and through a conductive junction lead to excitation of significantly different dipolar and charge transfer plasmon (CTP) resonances, respectively. Here, we demonstrate the excitation of dipolar and CTP resonant modes in metallic nanodimers bridged by phase-change material (PCM) sections, material and electrical characteristics of which can be controlled by external stimuli. Ultrafast switching (in the range of a few nanoseconds) between amorphous and crystalline phases of the PCM section (here Ge2Sb2Te5 (GST)) allows for designing a tunable plasmonic switch for optical communication applications with significant modulation depth (up to 88%)...
February 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28205530/retinal-structure-and-function-in-eyes-with-optic-nerve-hypoplasia
#14
Satoshi Katagiri, Sachiko Nishina, Tadashi Yokoi, Masashi Mikami, Yuri Nakayama, Michiko Tanaka, Noriyuki Azuma
We investigated retinal structure and function in eyes with optic nerve hypoplasia (ONH). Twenty-nine eyes of 18 patients with ONH and 21 eyes of 21 control patients were analyzed. Spectral-domain optical coherence tomography (SD-OCT), full-field electroretinography (FF-ERG), and focal macular ERG (FM-ERG) were performed. SD-OCT analysis of the macular region showed significant ganglion cells complex (GCC) thinning nasally and temporally (P < 0.05), but the thickness from the inner nuclear layer (INL) to the retinal pigment epithelium (RPE) became thinner only nasally (P < 0...
February 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28205510/controlling-second-harmonic-generation-at-the-nanoscale-with-monolithic-algaas-on-alox-antennas
#15
L Carletti, D Rocco, A Locatelli, C De Angelis, V F Gili, M Ravaro, I Favero, G Leo, M Finazzi, L Ghirardini, M Celebrano, G Marino, A V Zayats
We review recent achievements in the field of nanoscale nonlinear AlGaAs photonics based on all-dielectric optical antennas. After discussing the motivation and main technological challenges for the development of an AlGaAs monolithic platform for χ ((2)) nonlinear nanophotonics, we present numerical and experimental investigations of the second-order nonlinear response and physical reasons for high efficiency of second-order nonlinear interactions in the AlGaAs nano-antennas. In particular, we emphasize the role of the dipolar resonances at the fundamental frequency and the multipolar resonances at the second harmonic wavelength...
February 16, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28201961/development-and-characterization-pulsatile-microspheres-of-nifedipine-for-hypertension
#16
Rahul Taneja, Ghanshyam Das Gupta
AIM AND BACKGROUND: To develop pulsatile microspheres of Nifedipine blend of polymers Carbopol 971P and Eudragit RS100 for antihypertensive to release the drug at a particular lag time. METHODS: Pulsatile nifedipine microspheres were prepared using blend of Carbopol 971P and Eudragit RS100 at different ratio in a mixture of solvents. Formulations were prepared and optimized on the basis of particle size, percentage yield and drug entrapment efficiency. Optimized formulations were further analyzed at different resolutions per minute (rpm) by optical microscopy, scanning electron microscopy (SEM), in-vitro dissolution studies and kinetics model...
February 12, 2017: Recent Patents on Drug Delivery & Formulation
https://www.readbyqxmd.com/read/28199885/evaluation-of-polyesteramide-pea-and-polyester-plga-microspheres-as-intravitreal-drug-delivery-systems-in-albino-rats
#17
Tobias Peters, Seong-Woo Kim, Vinicius Castro, Krunoslav Stingl, Torsten Strasser, Sylvia Bolz, Ulrich Schraermeyer, George Mihov, MengMeng Zong, Vanessa Andres-Guerrero, Rocio Herrero Vanrell, Aylvin A Dias, Neil R Cameron, Eberhart Zrenner
PURPOSE: To study the suitability of injectable microspheres based on poly(ester amide) (PEA) or poly lactic-co-glycolic acid (PLGA) as potential vehicles for intravitreal drug delivery in rat eyes. Dexamethasone-loaded PEA microspheres (PEA + DEX) were also evaluated. METHODS: Forty male Sprague Dawley rats were divided into four groups that received different intravitreally injected microspheres: PEA group (n = 12); PLGA group (n = 12); PEA + DEX group (n = 8); and control group (no injection, n = 8)...
February 7, 2017: Biomaterials
https://www.readbyqxmd.com/read/28199027/investigating-the-level-of-salivary-endothelin-1-in-premalignant-and-malignant-lesions
#18
Tahereh Nosratzehi, Sirous Risbaf Fakour, Ebrahim Alijani, Maryam Salehi
PURPOSE: This study aimed to investigate the level of salivary endothelin-1 in premalignant and malignant lesions. MATERIALS AND METHODS: In this study, 75 cases were investigated of which 25 cases were healthy, 25 cases had oral lichen planus (OLP), and 25 cases had oral squamous cell carcinoma (OSCC). In order to collect the saliva samples, the unstimulated spitting was used. The samples were collected between 9 and 12 a.m. They were sent to the lab shortly after being collected and salivary endothelin-1 was recorded for each sample according to the instruction of factory by using enzyme-linked immunosorbent assay and optical density at a wavelength of 450 nm...
February 15, 2017: Special Care in Dentistry
https://www.readbyqxmd.com/read/28198882/integrated-photonic-power-divider-with-arbitrary-power-ratios
#19
Ke Xu, Lu Liu, Xiang Wen, Wenzhao Sun, Nan Zhang, Ningbo Yi, Shang Sun, Shumin Xiao, Qinghai Song
Integrated optical power splitters are one of the fundamental building blocks in photonic integrated circuits. Conventional multimode interferometer-based power splitters are widely used as they have reasonable footprints and are easy to fabricate. However, it is challenging to realize arbitrary split ratios, especially for multi-outputs. In this Letter, an ultra-compact power splitter with a QR code-like nanostructure is designed by a nonlinear fast search method. The highly functional structure is composed of a number of freely designed square pixels with the size of 120×120  nm which could be either dielectric or air...
February 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28198839/parametric-amplification-of-100-fs-mid-infrared-pulses-in-zngep-sub-2-sub-driven-by-a-ho-yag-chirped-pulse-amplifier
#20
Tsuneto Kanai, Pavel Malevich, Sarayoo Sasidharan Kangaparambil, Kakuta Ishida, Makoto Mizui, Kaoru Yamanouchi, Heinar Hoogland, Ronald Holzwarth, Audrius Pugzlys, Andrius Baltuska
We report on the parametric generation of 100 fs sub-6-cycle 40 μJ pulses with the center wavelength at 5.2 μm using a 1 ps 2.1 μm pump laser and a dispersion management scheme based on bulk material. Our optically synchronized amplifier chain consists of a Ho:YAG chirped-pulse amplifier and white-light-seeded optical parametric amplifiers providing simultaneous passive carrier-envelope phase locking of three ultrashort longwave pulses at the pump, signal, and idler wavelengths corresponding, respectively, to 2...
February 15, 2017: Optics Letters
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