3,505 research outputs found
Transmission of light through periodic arrays of square holes : from a metallic wire mesh to an array of tiny holes
A complete landscape is presented of the electromagnetic coupling between square holes forming a two-dimensional periodic array in a metallic film. By combining both experimental and theoretical results along with a first-principles Fano model, we study the crossover between the physics of metallic wire meshes (when holes occupy most of the unit cell) and the phenomenon of extraordinary optical transmission, which appears when the size of the holes is very small in comparison with the period of the array
Diodos emisores de luz para irradiación de plantas
Los recientes desarrollos conseguidos en el área de la iluminación con diodos emisores de luz (LEDs, cuando son inorgánicos, y OLEDs, cuando son orgánicos) resultan de gran interés en horticultura, al permitir manipular el espectro radiante que va a incidir sobre las plantas, con el objetivo de aumentar su producción o de generar determinados efectos fisiológicos, sobre todo en invernaderos. Puesto que los vegetales crecen mejor cuando son iluminados (irradiados) en las regiones roja y azul del espectro, resulta aconsejable sustituir los sistemas de iluminación fotosintética actuales, fundamentalmente mediante lámparas de descarga en gases (vapor de sodio a alta presión y, en menor medida, halogenuros metálicos), por LEDs comerciales que emiten separadamente en esas regiones o por OLEDs susceptibles de emisión conjunta. Además, estos dispositivos son más eficientes que las lámparas incandescentes (consumen mucha menor energía eléctrica y poseen una vida media de uso mucho más larga), no generan exceso de calor (y por tanto no dañan a plantas térmicamente sensibles), e incluso, en el caso de los LEDs rojos, repelen insectos, por lo que contribuyen a la disminución en el uso de agrotóxicos. En el presente artículo, se revisan las últimas contribuciones en Fitofotónica relacionadas con los diodos emisores de luz, se aporta la experiencia existente sobre la aplicación de LEDs a invernaderos y se divulga el estado de las investigaciones que algunos grupos de investigación estamos realizando sobre OLEDs emisores bien en el rojo o bien en las regiones del rojo y el azul
Myo/Nog Cells Give Rise to Myofibroblasts During Epiretinal Membrane Formation in a Mouse Model of Proliferative Vitreoretinopathy.
PURPOSE: Myo/Nog cells are the source of myofibroblasts in the lens and synthesize muscle proteins in human epiretinal membranes (ERMs). In the current study, we examined the response of Myo/Nog cells during ERM formation in a mouse model of proliferative vitreoretinopathy (PVR).
METHODS: PVR was induced by intravitreal injections of gas and ARPE-19 cells. PVR grade was scored by fundus imaging, optical coherence tomography, and histology. Double label immunofluorescence localization was performed to quantify Myo/Nog cells, myofibroblasts, and leukocytes.
RESULTS: Myo/Nog cells, identified by co-labeling with antibodies to brain-specific angiogenesis inhibitor 1 (BAI1) and Noggin, increased throughout the eye with induction of PVR and disease progression. They were present on the inner surface of the retina in grades 1/2 PVR and were the largest subpopulation of cells in grades 3 to 6 ERMs. All α-SMA-positive (+) cells and all but one striated myosin+ cell expressed BAI1 in grades 1 to 6 PVR. Folds and areas of retinal detachment were overlain by Myo/Nog cells containing muscle proteins. Low numbers of CD18, CD68, and CD45+ leukocytes were detected throughout the eye. Small subpopulations of BAI1+ cells expressed leukocyte markers. ARPE-19 cells were found in the vitreous but were rare in ERMs. Pigmented cells lacking Myo/Nog and muscle cell markers were present in ERMs and abundant within the retina by grade 5/6.
CONCLUSIONS: Myo/Nog cells differentiate into myofibroblasts that appear to contract and produce retinal folds and detachment. Targeting BAI1 for Myo/Nog cell depletion may be a pharmacological approach to preventing and treating PVR
Identification of active oxalotrophic bacteria by Bromodeoxyuridine DNA labeling in a microcosm soil experiments
The oxalate-carbonate pathway (OCP) leads to a potential carbon sink in
terrestrial environments. This process is linked to the activity of
oxalotrophic bacteria. Although isolation and molecular
characterizations are used to study oxalotrophic bacteria, these
approaches do not give information on the active oxalotrophs present in
soil undergoing the OCP. The aim of this study was to assess the
diversity of active oxalotrophic bacteria in soil microcosms using the
Bromodeoxyuridine (BrdU) DNA labeling technique. Soil was collected near
an oxalogenic tree (Milicia excelsa). Different concentrations of
calcium oxalate (0.5%, 1%, and 4% w/w) were added to the soil
microcosms and compared with an untreated control. After 12days of
incubation, a maximal pH of 7.7 was measured for microcosms with oxalate
(initial pH 6.4). At this time point, a DGGE profile of the frc gene was
performed from BrdU-labeled soil DNA and unlabeled soil DNA.
Actinobacteria (Streptomyces- and Kribbella-like sequences),
Gammaproteobacteria and Betaproteobacteria were found as the main active
oxalotrophic bacterial groups. This study highlights the relevance of
Actinobacteria as members of the active bacterial community and the
identification of novel uncultured oxalotrophic groups (i.e. Kribbella)
active in soils
Influence of chronic ocular hypertension on emmetropia: Refractive, structural and functional study in two rat models
Chronic ocular hypertension (OHT) influences on refraction in youth and causes glaucoma in adulthood. However, the origin of the responsible mechanism is unclear. This study analyzes the effect of mild-moderate chronic OHT on refraction and neuroretina (structure and function) in young-adult Long-Evans rats using optical coherence tomography and electroretinography over 24 weeks. Data from 260 eyes were retrospectively analyzed in two cohorts: an ocular normotension (ONT) cohort (20 mmHg), in which OHT was induced either by sclerosing the episcleral veins (ES group) or by injecting microspheres into the anterior chamber. A trend toward emmetropia was found in both cohorts over time, though it was more pronounced in the OHT cohort (p < 0.001), especially in the ES group (p = 0.001) and males. IOP and refraction were negatively correlated at week 24 (p = 0.010). The OHT cohort showed early thickening in outer retinal sectors (p < 0.050) and the retinal nerve fiber layer, which later thinned. Electroretinography demonstrated early supranormal amplitudes and faster latencies that later declined. Chronic OHT accelerates emmetropia in Long–Evans rat eyes towards slowly progressive myopia, with an initial increase in structure and function that reversed over time. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Dimorphic Fungal Coinfection as a Cause of Chronic Diarrhea and Pancolitis
Histoplasma capsulatum and Paracoccidioides brasiliensis are dimorphic fungi that cause systemic mycosis mostly in tropical South America and some areas of North America. Gastrointestinal involvement is not uncommon among these fungal diseases, but coinfection has not previously been reported. We report a patient with chronic diarrhea and pancolitis caused by paracoccidioidomycosis and histoplasmosis
Chronic Diarrhea and Pancolitis Caused by Paracoccidioidomycosis: A Case Report
South American blastomycosis is a systemic micosis caused by infection with Paracoccidioides brasiliensis. The most frequently affected sites are the lower lip buccal mucous membrane, palate, tongue, sublingual region, lymph glands, and lungs. However, colonic involvement is not a common expression of Paracoccidioidomycosis. We report a case of chronic diarrhea and pancolitis caused by Paracoccidioidomycosis with fatal outcome
Molecular Characterization of Growth Hormone-producing Tumors in the GC Rat Model of Acromegaly
D.A.C. was supported by the Nicolás Monardes
program of the Andalusian Ministry of Health (C-0015-2014) and by a grant from the Andalusian
Ministry of Science and Innovation (CTS-7478). A.S-M and A.L.C were supported by grants from
the ISCIII-Subdirección General de Evaluación y Fomento de la Investigación co-funded with Fondos
FEDER (PI12/0143 and PI13/02043, respectively) and the Andalusian Regional Government (CTS-444)
and a grant from Pfizer Spain. R.L.C. was supported by a grant from Andalusian Ministry of Health
(PI0302-2012). R.M.L. was supported by grants from Proyecto de Investigación en Salud (FIS) PI13-
00651 (funded by Instituto de Salud Carlos III), CTS-1406, PI-0639-2012, BIO-0139 (funded by Junta
de Andalucía) and by Ayuda Merck Serono 2013. J. P. C. was funded by a grant (BFU2013-43282-R)
from Ministerio de Economía y Competitividad. CIBER is an initiative of Instituto de Salud Carlos III,
Ministerio de Sanidad, Servicios Sociales e Igualdad, Spain. J.F.M.R. is supported by the “Sara Borrell”
program from the Instituto de Salud Carlos III. R.M. Luque and J.P. Castaño have received grants and
lecture fees from Ipsen and Novartis. E. Venegas-Moreno and A. Soto-Moreno received grants and lecture
fees from Ipsen, Novartis and Pfizer. A. Leal-Cerro received grants from Novartis and Pfizer. David
Cano received a grant from Novartis
Novel use of plga microspheres to create an animal model of glaucoma with progressive neuroretinal degeneration
Progressive degeneration of neuroretinal tissue with maintained elevated intraocular pressure (IOP) to simulate chronic glaucoma was produced by intracameral injections of poly (lactic-co-glycolic) acid (PLGA) microspheres (Ms) in rat eyes. The right eye of 39 rats received different sizes of PLGA-Ms (2 µL suspension; 10% w/v): 14 with 38–20 µm Ms (Ms38/20 model) and 25 with 20–10 µm particles (Ms20/10 model). This novel glaucoma animal model was compared to the episcleral vein sclerosis (EPI) model (25 eyes). Injections were performed at baseline, two, four and six weeks. Clinical signs, IOP, retina and optic nerve thicknesses (using in vivo optical coherence tomography; OCT), and histological studies were performed. An IOP increment was observed in all three groups, however, the values obtained from the PLGA-Ms injection resulted lower with a better preservation of the ocular surface. In fact, the injection of Ms20/10 created a gentler, more progressive, and more sustained increase in IOP. This IOP alteration was correlated with a significant decrease in most OCT parameters and in histological ganglion-cell count for the three conditions throughout the eight-week follow-up. In all cases, progressive degeneration of the retina, retinal ganglion cells and optic nerve, simulating chronic glaucoma, was detected by OCT and corroborated by histological study. Results showed an alternative glaucoma model to the well-known episcleral vein model, which was simpler to perform, more reproducible and easier to monitor in vivo
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