Optical Photos Research Articles

Deep learning-based structural health monitoring through the infusion of optical photos and vibration data

Deep learning-based structural health monitoring through the infusion of optical photos and vibration data

Wound Healing in a Porcine Model of Retinal Holes.

To investigate retinal wound healing, we created a new porcine model of retinal hole and identified the cells involved in hole closure. Sixteen landrace pigs underwent vitrectomy, and a subretinal bleb was created before cutting a retinal hole using a 23G vitrector. No tamponade was used. Before surgery and one, two, and four weeks after surgery, the eyes were examined by optical coherence tomography and color fundus photos. At the end of follow-up, the eyes were enucleated for histology. Tissue sections of 5 µm were prepared for hematoxylin-eosin staining and immunohistochemical analysis with antibodies to retinal glial and epithelial cells. Retinal holes below 1380 µm in diameter closed spontaneously within four weeks, whereas larger holes remained open. Hole closure was mediated by central movement of the edges of the hole and in most cases the formation of a gliotic plug. Fluorescence microscopy revealed that the plug consisted of cells positive for glial fibrillary acidic protein, indicating the presence of macroglial cell types. Specifically, the plug was positive for S100 calcium-binding protein B, mainly representing astrocytes, while it was negative for anti-glutamine syntethase, representing Müller glia. These findings suggest that astrocytes are the predominating cell type in the plug. Minimal glial reaction was seen in the retinal holes that did not close. We present a new porcine model for investigating large retinal holes. The retinal holes closed by approximation of hole edges, and the remnant retinal defect was closed with an astroglial plug.

Comparison of Glaucoma Diagnosis by Telemedicine, In-Person Ophthalmologist, and Optometrist.

Diagnosis of glaucoma through telemedicine demonstrates moderate agreement with in-person ophthalmologist (MD) and in-person optometrist (OD) diagnosis, providing evidence that telemedicine is a timely, accurate screening method in settings where an in-person visit may not be feasible. To compare diagnostic agreement of glaucoma between in-person MD, in-person OD, and a simulated telemedicine program. A cross-sectional study of patients with normal optic nerve structural and functional imaging and new patients referred for glaucoma evaluation examined in-person by an MD for glaucoma with a dilated examination and structural and functional optic nerve testing (optical coherence tomography, photos, and visual field); examined in person by an OD with a dilated examination and optic nerve testing; and structural and functional optic nerve testing reviewed separately by 2 ophthalmologists [telemedicine ophthalmologist reviewer 1 (TMD1), telemedicine ophthalmologist reviewer 2 (TMD2)] with masking of prior MD and OD diagnoses. Interrater agreement between each diagnostic method (MD, OD, TMD1, and TMD2) of normal versus disease (open angle glaucoma, normal tension glaucoma, other types of glaucoma, other optic nerve disorders, ocular hypertension, and glaucoma suspect) for each eye was calculated (Cohen unweighted kappa). A total of 100 patients with a median age of 66 years (interquartile range: 59-72), male (40%) and white (62%) were analyzed. There was moderate agreement between MD and telemedicine [TMD1 kappa 0.49 (95% CI: 0.37-0.61), TMD2 kappa 0.44 (95% CI: 0.32-0.56)] and between MD and OD diagnosis [0.41 (95% CI: 0.28-0.54)] and fair-moderate agreement between OD and telemedicine [TMD1: 0.46 (95% CI: 0.34-0.58), TMD2: 0.61 (95% CI: 0.50-0.72)]. The simulated telemedicine approach had comparable levels of agreement in glaucoma diagnosis with in-person fellowship-trained ophthalmologists, presenting a crucial complementary role in screening and increasing access to care, particularly in rural or underserved settings.

Effect of interlaminar basalt fiber veil reinforcement on mode I fracture toughness of basalt fiber composites

AbstractComposite structures are vulnerable to delamination under out‐of‐plane loading due to the absence of reinforcing fibers in the thickness direction. This paper introduced the interlaminar basalt fiber veil technique to improve the interlaminar fracture toughness of basalt fiber‐reinforced thermoplastic composite laminates. The reinforcement effect of the basalt fiber veil on GIC of composite laminates was investigated by a double cantilever beam (DCB) test. The toughening effect, damage morphology, and the basalt fiber veil toughening mechanism were analyzed by mechanical response, optical photos, and scanning electron microscopy (SEM). It was found that the basalt fiber veil could significantly inhibit the propagation of interlaminar cracks. Compared to the unreinforced specimen, the maximum load of basalt fiber veil‐reinforced laminate was increased by 73%, the average platform load was increased by 72.7% and the GIC was increased by 157%.Highlights Improvement of GIC of basalt fiber‐reinforced thermoplastic laminates by basalt fiber veil. The toughening mechanism for the basalt fiber veil. The GIC of the fiber veil‐reinforced laminate was 157% higher than the unreinforced laminate.

CENTRAL RETINAL ARTERY OCCLUSION AS PRESENTATION OF BARTONELLA ENDOCARDITIS.

To describe a rare ocular presentation of a systemic illness and the important lifesaving diagnosis made by a complete eye examination. The patient was evaluated with a comprehensive ophthalmic examination and followed closely in the outpatient setting with optical coherence tomography, fluorescein angiography, and color fundus photos. A 66-year-old man presented with acute vision loss of the left eye. A complete eye examination revealed that he had a central retinal artery occlusion. Systemic workup revealed that he had a mitral valve vegetation and blood cultures grew Bartonella henselae. His kidney biopsy showed membranoproliferative glomerulonephritis, which is often seen with septic emboli. Furthermore, the patient lacked any ocular inflammatory signs. This constellation of findings was diagnostic for a thromboembolic etiology causing his central retinal artery occlusion. At follow-up, the optical coherence tomography demonstrated inner retinal hyperreflectivity and the fluorescein angiogram showed segmented flow and no neovascularization. On follow-up, the patient had a stable examination with light perception vision and completed antibiotic therapy for bartonella endocarditis. The detection of a fatal systemic illness was made promptly with a thorough ocular examination. We highlight the importance of a multidisciplinary approach in making a lifesaving diagnosis.

Optically tunable dielectric response of TiO2:MAPbI3 nanocomposite thin films

We report on the optically tunable dielectric response of TiO2:MAPbI3 nanocomposite thin films via the electron injection from the CH3NH3PbI3 (MAPbI3) crystals to the TiO2 nanoparticles. The equivalent circuit analysis shows that the dielectric responses can be classified into the inner regions of dielectric media and the TiO2/MAPbI3 interfaces. Optical photos, atomic-force microscopic images, photoluminescence spectra, Raman scattering spectra, and X-ray diffraction patterns show that the TiO2:MAPbI3 thin film contains two different regions. The brighter and darker regions consist of isolated MAPbI3 rods and TiO2:MAPbI3 nanocomposites, respectively. It is noted that the real part of dielectric constant of the TiO2:MAPbI3 (3:1) composite thin film largely increases from 397 to 557 at the frequency of 40 kHz with one sun illumination, which opens a way to create optically tunable devices such as active antennas and active filters.

Regulation mechanism of porous structures on flashover performances: combined effect of hindering collision ionization and corona stabilization

The microscopic morphology is recognized as one of the key factors affecting the surface flashover strength, but the effect of nanoscale morphology is rarely investigated. In this paper, a novel strategy, namely, porous structural material was presented to improve the flashover strength, and porous nylon membranes with pore diameter from 100 nm to 5000 nm were used to explore the influence of nano-scale porous morphology on the flashover strength. The regulation mechanism of porous structures on flashover performances were explored through the analysis of potential scanning, partial discharge measurement, corona and flashover optical photos. The results indicated that the flashover strength under both AC and DC voltages could be significantly improved by the porous morphology, with a maximum increment of higher than 100%. It is believed that the improved flashover strength is attributed to the combined effect of hindering collision ionization and corona stabilization of porous structures. The present research provides a new insight for improving the surface insulation performance.

Anisotropic Fracture of Sandstone with Biotreated Cracks

Biotreatment has the potential to be used in restoration and conservation of stone-cultural relics, but less research has been focused on the anisotropic strength of rock with biotreated cracks. In this study, a series of Brazilian splitting tests (BSTs) was conducted on the intact disc sandstone specimens to generate mimicking natural cracks. A specifically designed biocementing system was then adopted to form effective biocementation between the two halves of the specimen, as indicated by microimages. The sandstone specimens with a biotreated crack were then subjected to BSTs at different loading angles. The apparent tensile strength (ATS) of the biotreated specimen can reach and even exceed that of the intact specimen, with low anisotropy. Furthermore, four failure modes are identified based on optical photos. The aforementioned findings reveal that the biotreatment is a remarkable method for repairing cracks of stone-cultural relics.

Environmentally friendly g-C3N4/carbon quantum dots nanocomposites as fluorescent and anti-spoofing inks

The major goal of this research is to examine fluorescence (FL) features and application of graphitic carbon nitride/carbon quantum dots (GCN/CQD) nanocomposites as invisible and anti-spoofing inks. GCN/CQD nanocomposites were used for an environmentally friendly synthesis method. To achieve this, starch and urea were, respectively, applied as a natural source of carbon and a nitrogen resource. The mixtures of starch and urea with a weight ratio of 1:5 and 1:10 were synthesized using a two-step pyrolysis and microwave-assisted method. FL behavior of the GCN/CQD aqueous colloids indicated that a change in the urea concentration could result in FL emission in the various areas of visible light. FL emission spectra of the synthesized sample with low amount urea and in the sample including extra urea were, respectively, observed at blue and green regions. Anti-spoofing function of these nanocomposites as inks were confirmed via optical spectroscopy testing and digital photos taken from UV cabinet. The photos and patterns taken from the ink made of GCN/CQD nanocomposites are nearly invisible under daylight but clear and observable open to UV, as a result one could conclude that these are potentially usable in anti-spoofing function of the secure inks.

A novel type of serum‑free medium for culturing human airway epithelium cells.

The present study aimed to evaluate the ability of a novel serum-free medium (SFM) to culture human airway epithelium cells (hAECs). hAECs were cultured in the novel SFM as the experimental group in the PneumaCult-Ex medium and Dulbecco's modified eagle medium (DMEM) and fetal bovine serum (FBS) as the control groups. Cell morphology, proliferative capacity, differentiation capacity and expression levels of basal cell markers were assessed accordingly in both culture systems. Optical microscope photos of hAECs were collected for cell morphology assessment. Cell Counting Kit-8 assay was conducted to assess the proliferation ability, and an air-liquid interface (ALI) assay was conducted to assess the differentiation capacity. Markers for proliferating basal and differentiated cells were relatively identified by immunohistochemical and immunofluorescent analysis. The results show that whether grown in the novel SFM or Ex medium, hAECs exhibited similar morphology at every passage, whereas cells could hardly form colonies in the DMEM + FBS group. Cells typically exhibited cobblestone shape, while a proportion of them in the novel SFM at late passage exhibited a larger shape. White vesicles appeared in the cytoplasm of some control cells at the later stage of culture. Basal cell markers (P63+KRT5+KI67+CC10-) for proliferating ability were found in the hAECs cultured by the novel SFM and Ex medium. hAECs at passage 3 cultured in the novel SFM and Ex medium both had the capacity to differentiate into ciliated cells (acetylated tubulin+), goblet cells (MUC5AC+) and club cells (CC10+) in the ALI culture assay. In conclusion, the novel SFM was capable of culturing hAECs. The hAECs cultured by the novel SFM could proliferate and differentiate in vitro. The novel SFM does not change the morphological characteristics or biomarkers of hAECs. The novel SFM has the potential for the amplification of hAECs for scientific research and clinical application.

Fracture of Interparticle MICP Bonds under Compression

Microbiologically induced calcium carbonate precipitation (MICP), as a promising reinforcement technique, has been investigated extensively through element and model tests. However, tests on the particle-scale behaviors of MICP bonds are rarely conducted yet, which constrains the development of constitutive and numerical models of MICP-treated sands. In this paper, a set of devices is designed to form MICP bonds between spherical quartz beads (SQBs) and spherical calcareous beads (SCBs) and investigate the microscopic compression behavior of the interparticle MICP bonds in comparison with portland cement (PC) bonds. The experimental results reveal that the PC bonds are the strongest, whereas the MICP bonds between SQB are the weakest. A higher cementation degree leads to higher strength and smaller dispersion among parallel specimens, while a larger interparticle distance causes smaller strength and greater dispersion. Identified with force–displacement curves and optical photos, the PC-treated SQB specimens are dominated by brittle failure, the MICP-treated SQB specimens can present ductile or brittle failure, and possible grain crushing is observed in the MICP-treated SCB specimens. Scanning electron microscopy (SEM) images suggest better interfacial bonding for the MICP-treated SCB specimens than for the MICP-treated SQB specimens. Gravity-related inhomogeneity is observed in the MICP bonds, whereas a homogeneous dense microstructure is observed in the PC bonds.

Effect of plasma irradiation on the electrical characteristics of the PMMA-PS/Al2O3 nanocomposites

A nanocomposite consisting of (PMMA/PS) polymeric blend was prepared with the nanomaterials (Al2O3) by the casting method. The structural and dielectric characteristic were studied. The optical microscope photos demonstrated high homogeneousness and fine dispersal of Al2O3 NPs inside the blend polymer films, as well as the formation of charge transfer complex. The FTIR indicate to a physical interference between the polymer matrix and nanoparticles. SEM images showed agglomeration of small and close packed group of elliptical particles on the surface of the polymeric matrix as a result of adding different number of Al2O3 NPs. The insulator constant and the insulator loss of the (PMMA-PS/Al2O3) nanocomposites reduce with the rise in frequency, while the A.C electrical conductivity increases with increase of the frequency. The insulator constant, insulator loss and A.C electrical conductivity of (PMMA-PS/Al2O3) nanocomposites rises with raising of Al2O3 nanoparticles concentrations. The dielectric constant, dielectric loss and A.C electrical conductivity after irradiation have high values compared before irradiation which attributed to the plasma interact with the molecular of these nanocomposites. As a results of their improved electrical conductivity after irradiation, polymeric nanocomposites have been proposed for use in electronic devices, sensors, and batteries.

Active and passive mixed millimeter wave imaging target recognition method based on multi‐feature fusion

Due to millimeter-wave (MMW) has a strong ability to penetrate clothing, MMW holographic imaging technology can conduct a non-contact inspection of the human body's surface. Therefore, it is of great significance to study the security inspection equipment and target recognition technology based on millimeter wave imaging. In this paper, an active and passive hybrid millimeter wave imaging target recognition method based on multi-feature fusion is proposed, which improves the ability of the imaging system to identify different dangerous targets. First, active and passive millimeter wave imaging techniques are discussed, the reconstruction algorithm of active millimeter wave holographic imaging is derived in detail, and the measured optical photos and data of active and passive imaging are obtained. Secondly, the image preprocessing technology applied to active and passive millimeter wave imaging is studied, which can effectively highlight the target, eliminate background interference, and clearly describe the target contour. Then the methods of image feature extraction, data feature extraction and multi-feature fusion are studied. On this basis, a multi-feature fusion method based on weighted series fusion is proposed to obtain the fusion feature vector form of active and passive MMW imaging. Finally, this paper proposed the target recognition method applied to millimeter wave imaging, and concludes that the fusion feature vector is better than the original feature vector, which provides an idea for the fusion of active and passive millimeter wave imaging at the feature level. It also provides a theoretical basis for the application of security equipment.

Retinal arterial tortuosity in Ehlers–Danlos syndromes

PurposeTo report a novel finding of retinal arterial tortuosity (RAT) associated with Ehlers–Danlos syndromes (EDS).MethodsWe queried the STAnford Research Repository (STARR) database to identify patients diagnosed with EDS. We included patients with a confirmed diagnosis of any subtype of EDS who had any form of readable retinal imaging including colour fundus photos, autofluorescence, red-free photos, red-free optical coherence tomography photos and fluorescein angiography. Patients who had no retinal imaging and those with no confirmed EDS diagnosis were excluded. Retinal images were reviewed for RAT and were graded into no, possible and definite RAT. Eyes with definite RAT were further graded into mild, moderate and severe. Eyes with definite RAT were again subclassified according to the type of involved vessels into first-order arteriolar, macular and arteriovenous.ResultsA total of 307 patients were identified using the STARR tool and 142 patients were included. Mean age was 40.9 ± 18.1 years and 87% were female. Underlying EDS subtypes were hypermobile EDS (69.7%), classical EDS (2.8%), vascular EDS (2.1%), myopathic EDS (0.7%) and not specified (24.6%). We graded 37.3% of patients with definite RAT, 10.6% with possible RAT and 52.1% with no RAT. In patients with definite RAT, we graded 39.2% of eyes with mild RAT, 40.2% with moderate RAT and 20.6% with severe RAT. In all, 84.9% showed involvement of first-order retinal arterioles, 35.8% showed involvement of macular arterioles and 1.9% showed arteriovenous involvement.ConclusionsVariable degrees of RAT are associated with EDS.

Monitoring fotogrametryczny z wykorzystaniem bezzałogowego statku powietrznego na przykładzie osuwiska zlokalizowanego na zboczach poeksploatacyjnego zbiornika wodnego w KWB Adamów

The article presents the results of monitoring of landslides related to opencast mining. The landslides formed on the slopes of an artificial water reservoir in the Adamów open-cast lignite mine. The photogrammetric method was used for monitoring. The study of landslide activity was performed on the basis of six photogrammetric surveys made with the DJI Phantom 4 Advanced UAV. Changes in the landslide extent and vertical displacements were determined in five measurement periods. For four periods, differential digital terrain models were made and the volume of displaced earth masses was calculated. The future extent of the landslide was determined on the basis of cracks visible in high-resolution optical photos. The research has shown that UAVs equipped with an optical camera are very useful in monitoring the stability of slopes of post-mining water reservoirs. The applied method provided detailed data on the size of displacements without compromising on safety of people involved in field surveys.

Colorimetric analysis through electrospun WO3/PAN membrane for indication of oxygen in food packaging using a smartphone

Colorimetric oxygen indicator for food packaging is highly demanding owing to their increasing need for food freshness inspection, production efficiency, and the package's integrity. It is satisfying to develop colorimetric oxygen indicators based on cost-effective, robust, and fast-responding chromic systems. Here, we synthesize WO3/polyacrylonitrile nanofiber membranes (WO3/PAN NFM) through electrospinning. The photo-reduced NFM shows a dark blue color and can be easily oxidized to light yellow color by the oxygen in the air, which can be worked as the colorimetric oxygen indicator. Most of the WO3 nanoparticles are distributed on the surface of the fiber, and the porosity of the NFMs also enables them to absorb oxygen molecules faster and easier. Furthermore, a smartphone was used in the visual detection by identifying the RGB value of the optical photos of NFMs. The application of smartphones has greatly shortened the detection time and reduced detection cost, providing a new strategy for detecting food quality anytime and anywhere.

Double torpedo maculopathy in an adolescent patient

Torpedo maculopathy is a rare, typically singular, asymptomatic, unilateral torpedo-shaped lesion located in the temporal macula. The pathophysiology of these lesions is currently unknown but is thought to occur during embryogenesis. Even rarer are cases of torpedo maculopathy with two lesions in the affected eye, with only one prior case identified in the literature. The authors present a case of double torpedo maculopathy with accompanying optical coherence tomography, fundus photos, and fundus auto-fluorescence imaging over a 1.5-year follow-up period. Although our case further establishes the non-progressive nature of this phenotype, the exact pathophysiology warrants further investigation.

Effectively remove printing ink from plastic surface over quaternary ammonium-modified waste cooking oil

ABSTRACT The printing ink on the plastic surface will greatly reduce the quality of recycled plastic products. In this work, quaternary ammonium-modified waste cooking oil (WCOEQ) was fabricated using waste cooking oil, epichlorohydrin, and trimethylamine aqueous solution as raw materials, through ring-opening esterification and quaternary amination reaction. The synthesis conditions of WCOEQ were optimised, and the structure and properties of WCOEQ were characterised by Fourier transform infrared spectroscopy, zeta potential, and 1H NMR. Furthermore, WCOEQ had excellent emulsifying performance, low kraft point, low critical micelle concentration value, good foaming, and stability, which could effectively reduce the surface tension of water, showing application potential in the field of plastic deinking. Importantly, compared with the waste cooking oil without deinking effect, the WCOEQ had an excellent deinking performance on the ink on the plastic surface, and the deinking efficiency could be improved by increasing the concentration of the deinking agent, the deinking temperature, and prolonging the pre-soaking and stirring time. The results of atomic force microscope, energy-dispersive spectroscopy, optical photos, and Leica microscope showed that the roughness changed significantly and the ink molecules were gradually peeling off. This work highlighted the potential of quaternary ammonium-modified waste cooking oil for excellent removal of printing inks on the plastic surface.

Material Preparation and Geotechnical Properties of Transparent Cemented Soil for Physical Modeling

The preparation of transparent materials suitable for simulating different rock and soil masses is the foundation for image-based physical modeling tests in studying deformation and failure mechanisms in geotechnical media. A transparent cemented soil (TCS) with similar geotechnical properties of natural soil and soft rock was prepared using fused quartz as the skeleton, hydrophobic fumed silica powder as the cement and mixed mineral oil of 15# white oil and n-dodecane as the pore fluid. Eleven groups of TCS samples with different shear strengths were synthesized by adjusting the content or mass ratio of the cement and particle size or gradation of the skeleton. Contrasting tests of unconsolidated-undrained triaxial compression were carried out and the mechanical characteristics of TCS were analyzed, showing that the stress-strain relationship, shear strength and failure mode of TCS are similar to those of natural soil. The mechanical parameters of TCS undergo complex variation with the factors, and the mesoscopic mechanism of the changes therein was revealed with the help of optical microscope photos. The similarity ratio of TCS to soft rock was derived according to geometries and stress conditions of laboratory model tests, demonstrating the feasibility of using TCS as similar materials to soft rock. Moreover, empirical formulas for the change of shear strength parameters with the factors were fitted to facilitate the preparation of TCS with target shear strength in the future. The findings can provide a basis for preparing transparent similar materials to natural soil and soft rock in physical modeling tests.

Bright Structural Color and High Hydrophobic Properties of Photonic Crystal Films on the Ceramic Glaze Layer via Vertical Deposition Self‐Assembly Method

AbstractIn this work, structural color films on ceramic substrate were prepared through vertical deposition self‐assembly. The morphology, optical property and hydrophobicity of the films were characterized by field‐emission scanning electron microscopy (FE‐SEM), optical photos and contact angle meter. The results show that the SiO2 colloidal crystals with ordered arrangement are successfully immersed into the ceramic glaze after sintered, and the structural color films prepared on the ceramic glaze layer show a periodically ordered structure. Compared with the structural color films on alumina substrate, further researches on the structural color films on ceramic substrate were carried out, and the hydrophobic property and stability of the structural color films on ceramic substrate are better, which is attributed to the combination of SiO2 photonic crystal and ceramic glaze. Moreover, the structural color films on the ceramic glaze layer show excellent hydrophobic performance when the sintering temperature was 600 °C.