Thermoplasmonic Effect of Surface-Enhanced Infrared Absorption in Vertical Nanoantenna Arrays

Thermoplasmonics is a method for increasing temperature remotely using focused visible or infrared laser beams interacting with plasmonic nanopartides. Here, local heating induced by mid-infrared quantum cascade laser illumination of vertical gold-coated nanoanterma arrays embedded into polymer layers is investigated by infrared nanospectroscopy and electromagnetic/thermal simulations. Nanoscale thermal hotspot images are obtained by a phototherrnal scanning probe microscopy technique with laser illumination wavelength tuned at the different plasmonic resonances of the arrays. Spectral analysis indicates that both Joule heating by the metal antennas and surface-enhanced-infrared absorption (SEIRA) by the polymer molecules located in the apical hotspots of the antennas are responsible for thermoplasmonic resonances, that is, for strong local temperature increase. At odds with more conventional planar nanoantennas, the vertical antenna structure enables thermal decoupling of the hotspot at the antenna apex from the heat sink constituted by the solid substrate. The temperature increase was evaluated by quantitative comparision of data obtained with the photothermal expansion technique to the results of electromagnetic/thermal simulations. In the case of strong SEIRA by the C=O bond of poly-methylmethacrylate at 1730 cm(-1), for focused mid-infrared laser power of about 20 mW, the evaluated order of magnitude of the nanoscale temperature increase is of 10 K. This result indicates that temperature increases of order of hundreds of K may he attainable with full mid-infrared laser power tuned at specific molecule vibrational fingerprints

Corneal confocal microscopy in dry eye treated with corticosteroids

Purpose To evaluate, by in vivo laser scanning confocal microscopy (LSCM), the corneal findings in moderate-to-severe dry eye patients before and after treatment with topical corticosteroid and to associate the confocal findings to the clinical response. Methods Fifty eyes of 50 patients with moderate-to-severe dry eye were included in this open-label, masked study. Exclusion criteria were any systemic or ocular condition (other than dry eye) and any systemic or topical treatment (except artificial tears), ongoing or performed in the previous 3 months, with known effect on the ocular surface. All patients were treated with loteprednol etabonate ophthalmic suspension 0.5% qid for 4 weeks. Baseline and follow-up (day 30 \ub1 2) visits included Ocular Surface Disease Index (OSDI) questionnaire, full eye examination, and central cornea LSCM. We compared data obtained before and after treatment and looked for associations between baseline data and steroid-induced changes. Based on the previously validated OSDI Minimal Clinically Important Difference, we reanalyzed the baseline findings comparing those patients clinically improved after steroids to patients not clinically improved after steroids. Results Ocular Surface Disease Index score and LSCM dendritic cell density (DCD) significantly decreased after treatment. Baseline DCD correlated with both OSDI and DCD steroid-related changes (r = -0.44, p 2, p < 0.01; independent samples t test). Conclusions Laser scanning confocal microscopy examination of DCD allows detection of treatment-related inflammation changes and shows previously unknown associations between confocal finding and symptoms improvement after treatment. These promising preliminary data suggest the need for future studies testing the predictive value of DCD for a clinical response to topical corticosteroids

Drusen-like Deposits in Young Adults Diagnosed with Systemic Lupus Erythematosus

PURPOSE: To determine the prevalence of drusen-like deposits (DLDs) and choroidal changes in patients with Systemic Lupus Erythematosus (SLE), with or without glomerulonephritis. To correlate ocular findings with systemic features. DESIGN: Case-control study METHODS: Sixty patients with SLE (18-55 years; 30 with and 30 without SLE-related glomerulonephritis) and 60 age and gender matched healthy controls were enrolled. All patients underwent non-invasive, multimodal imaging that included fundus photography, near-infrared reflectance, blue autofluorescence, blue reflectance, and spectral-domain optical coherence tomography (SD-OCT). Images were analyzed for the prevalence of DLDs. Distribution, size, and number of DLDs were measured. Correlations between ocular findings and systemic features were analyzed. Subfoveal choroidal thickness (SCT) was measured using the SD-OCT. RESULTS: Drusen-like deposits were detected in 40% of SLE subjects and 3.33% of controls (P3 quadrants (P<0.001, P=0.03, P=0.009, respectively). Subfoveal choroidal thickness was greater in patients with SLE (P=0.002). CONCLUSIONS: Drusen-like deposits in patients with SLE were independent of renal disease and were best detected with SD-OCT. Lupus-related glomerulonephritis was associated with more fundus abnormalities and a screening SD-OCT should be considered in all patients with SLE. Drusen like deposits in the absence of glomerulonephritis may support the recent proposal that complement alteration is the primary cause for these lesions

3D nanoporous antennas as a platform for high sensitivity IR plasmonic sensing

Nanoporous gold can be exploited as plasmonic material for enhanced spectroscopy both in the visible and in the near-infrared spectral regions. In particular, the peculiar morphology of such a substrate leads to a higher field confinement with respect to conventional plasmonic materials. This property can be exploited to achieve extremely high sensitivity to the changes in environmental conditions, making it an interesting tool for the development of sensors and biosensors. Here, we compared the sensitivity of a plasmonic resonator made of nanoporous gold with a similar structure made of homogeneous gold. To assess the enhanced sensitivity the same stoichiometric quantity of dielectric material was deposited via Atomic Layer Deposition onto the two considered structures. Experimental results proved the higher sensitivity was achievable using nanoporous gold. In particular. such 3D nanoporous structures can be proposed as a promising sensing platform in the near-infrared with a sensitivity over 4.000 nm/RIU. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreemen

Evaluation of a novel eyelid-warming device in meibomian gland dysfunction unresponsive to traditional warm compress treatment : an in vivo confocal study

The purpose of the study was to evaluate the efficacy and safety of wet chamber warming goggles (Blephasteam(\uae)) in patients with meibomian gland dysfunction (MGD) unresponsive to warm compress treatment. We consecutively enrolled 50 adult patients with low-delivery, non-cicatricial, MGD, and we instructed them to apply warm compresses twice a day for 10\ua0min for 3\ua0weeks and to use Blephasteam(\uae) (Laboratoires Thea, Clermont-Ferrand, France) twice a day for 10\ua0min for the following 3\ua0weeks. We considered "not-responders" to warm compress treatment the patients who showed no clinically significant Ocular Surface Disease Index (OSDI) improvement after the first 3\ua0weeks. Clinical and in vivo confocal outcome measures were assessed in the worst eye (lower BUT) at baseline, after 3\ua0weeks, and after 6\ua0weeks. Eighteen/50 patients were not-responders to warm compress treatment. These patients, after 3\ua0weeks of treatment with Blephasteam(\uae), showed significant improvement of OSDI score (36.4\ua0\ub1\ua015.8 vs 20.2\ua0\ub1\ua012.4; P\ua0<\ua00.05, paired samples t test), increased BUT (3.4\ua0\ub1\ua01.6 vs 7.6\ua0\ub1\ua02.7; P\ua0<\ua00.05), and decreased acinar diameter and area (98.4\ua0\ub1\ua018.6 vs 64.5\ua0\ub1\ua014.4 and 8,037\ua0\ub1\ua01,411 vs 5,532\ua0\ub1\ua01,172, respectively; P\ua0<\ua00.05). Neither warm compresses nor Blephasteam(\uae) determined adverse responses. In conclusion, eyelid warming is the mainstay of the clinical treatment of MGD and its poor results may be often due to lack of compliance and standardization. Blephasteam(\uae) wet chamber warming goggles are a promising alternative to classical warm compress treatment, potentially able to improve the effectiveness of the "warming approach.

The cornea in classic type ehlers-danlos syndrome : macro- and microstructural changes

PURPOSE. To analyze in vivo corneal morphology and ultrastructural features in patients with classic Ehlers-Danlos syndrome (EDS). METHODS. Fifty patients with classic EDS and 50 age- and sex-matched control subjects were studied. A clinical evaluation was made with the Ocular Surface Disease Index (OSDI) questionnaire and a complete ophthalmic examination, including assessment of the bestcorrected visual acuity and refraction, slit-lamp biomicroscopy, tear break-up time, intraocular pressure, Schirmer test without topical anesthesia, and corneal diameter. Scheimpflug camera topography and in vivo confocal microscopy (IVCM) were used to investigate corneal morphology and corneal ultrastructural features respectively. RESULTS. Classic EDS patients, compared to controls, had thinner and steeper corneas (P < 0.001 and P < 0.05, respectively; independent samples t-test). IVCM showed thinner stromas, lower keratocyte densities (P < 0.001), increased applanation-related stromal folds (P < 0.001; Mann-Whitney U test), and increased endothelial hyperreflective dots (P < 0.05) in these patients. The study group also had increased symptoms (OSDI score: P < 0.01, independent samples t-test) and signs (tear break-up time and Schirmer test: P < 0.001 and P < 0.05, respectively) of tear film dysfunction. CONCLUSIONS. Patients with classic EDS had macro- and microstructural changes of the cornea, which is a target tissue of the disease. These findings should be considered to optimize clinical management of these patients and to evaluate the opportunity of adding ocular findings to the classic EDS diagnostic criteria

Nanoporous gold metamaterials for high sensitivity plasmonic sensing

Surface plasmon resonance sensors are a well-established class of sensors that includes a very large variety of materials and detection schemes. However, the development of portable devices is still challenging due to the intrinsic complexity of the optical excitation/detection schemes. This work shows that nanoporous gold (NPG) films can overcome the said limitations by providing an excellent sensitivity without the need for sophisticated fabrication approaches and/or optical setups. The sensing mechanism is related to the co-localization of optical energy and analytes in the pores fostering an enhanced light-matter coupling. As a result, when molecules are adsorbed in the pores, the NPG film shows a significant spectral shift of the effective plasma frequency and an abrupt change of the reflectivity. By monitoring the reflectivity in the spectral region close to the plasma frequency (namely the plasma edge), it is possible to detect the analyte. Through a series of experiments, the authors demonstrated a sensitivity exceeding 15 000 nm per RIU in the near infrared range comparable with the state of the art of plasmonic metamaterials

Coreactant electrochemiluminescence at nanoporous gold electrodes

The electrochemiluminescence (ECL) performances were comparatively investigated at flat and nanoporous gold (NPG) electrodes of different thicknesses (120 and 200 nm) and roughness factors (fr). The phenomena were studied using either tripropylamine (TPrA) or peroxydisulfate (S2O82-) as sacrificial coreactant and Ruthenium (II)- tris(2,2'-bipyridine) as emitting species. The experiments performed using TPrA showed, at first glance, a linear dependence of the ECL emission with respect to the effective surface area of the NPG electrodes. However, ECL signals were not stable in the measuring conditions, presumably due to amine absorption on the metal surface, leading to electrode corrosion and modification of the surface morphology. The experiments made using peroxydisulfate as coreactant provided conversely a stable ECL response, about proportional to the effective electrode surface area, in the considered range of thicknesses. (C) 2018 Elsevier Ltd. All rights reserved

Analisi delle sopravvivenze di pazienti affetti da NSCLC pN2 &#8220;occulto&#8221;, confront tra single e multi-station

La scelta tra le diverse opzioni di trattamento del NSCLC non pu\uf2 prescindere da un\u2019accurata stadiazione di malattia, in particolare riguardo all\u2019interessamento linfonodale ilo-mediastinico.Nonostante i progressi tecnologici nel campo dell\u2019imaging (TC, PET) e delle tecniche diagnostiche mini-invasive (EBUS, EUS) che consentono di discriminare tra stadi iniziali e avanzati di malattia, talvolta l\u2019analisi istopatologica post-operatoria dei linfonodi asportati rivela un coinvolgimento N2 in pazienti precedentemente stadiati cN0 o cN1 (pN2 \u201cocculti\u201d). In questo gruppo di pazienti il coinvolgimento di un\u2019unica stazione linfonodale (pN2 single-station) sembrerebbe correlare con una migliore sopravvivenza. Outcome primario di questo studio \ue8 il confronto delle sopravvivenze tra pN2 occulti single-station e multi-station. End point secondario \ue8 l\u2019individuazione di fattori predittivi di coinvolgimento linfonodale