Diagnosis and treatment of filamentary keratitis in a patient with Demodex infestation--an overlooked risk factor: a case report.

BACKGROUND: Filamentary keratitis is an ocular condition that is tricky to handle for the difficulty to find the underlying cause. Here we report a case of filamentary keratitis associated with Demodex infestation which highlights the importance of Demodex mites as an easily-overlooked risk factor. CASE PRESENTATION: A 63-year-old woman had recurrent symptoms of foreign body sensation and sometimes painful feelings in her left eye soon after her surgical correction of ptosis in this eye. She was then diagnosed as conjunctivitis and given antibiotic eye drops. After one week, the patient complained of aggravation of symptoms with small corneal filaments in the left eye under slit-lamp examination. Despite the removal of filaments and addition of topical corticosteroids and bandage contact lenses, the patient's condition persisted with enlarged filaments and severe ocular discomfort. 3 days later, eyelashes with cylindrical dandruff were noticed and Demodex infestation was confirmed by microscopic examination of these eyelashes at our clinic this time. She was asked to use tea tree oil lid scrub twice daily. After 3 weeks, her filamentary keratitis was resolved with a dramatic improvement in symptoms and signs. And no recurrence of filamentary keratitis was noticed during the one-year follow-up. CONCLUSIONS: In this case, filamentary keratitis was resolved only with treatment of Demodex infestation while conventional treatment failed. Considering the fact that Demodex infestation is a common but easily overlooked condition, it may be suggestive to take Demodex infestation into account as a risk factor of filamentary keratitis, especially in refractory cases.

Evaluation of the Properties of Eddy Current Sensors Based on Their Equivalent Parameters.

This paper presents a practical way of using the method of evaluating the metrological properties of eddy current sensors. The idea of the proposed approach consists of employing a mathematical model of an ideal filamentary coil to determine equivalent parameters of the sensor and sensitivity coefficients of tested physical quantities. These parameters were determined on the basis of the measured value of the real sensor's impedance. The measurements were carried out with an air-core sensor and an I-core sensor while they were positioned at different distances from the surface of tested copper and bronze plates. An analysis of the influence of the coil's position in relation to the I core on the equivalent parameters was also carried out, and the interpretation of the results obtained for various sensor configurations was presented in a graphical form. When equivalent parameters and sensitivity coefficients of examined physical quantities are known, it is possible to compare even very different sensors with the employment of one measure. The proposed approach makes it possible to make a significant simplification of the mechanisms of calibration of conductometers and defectoscopes, computer simulation of eddy current tests, creating the scale of a measuring device, and designing sensors.

First-principles simulation of neutral and charged oxygen vacancies in m-ZrO2: an origin of filamentary type resistive switching.

Metal oxide ZrO2has been widely explored for resistive switching application due to excellent properties like high ON/OFF ratio, superior data retention, and low operating voltage. However, the conduction mechanism at the atomistic level is still under debate. Therefore, we have performed comprehensive insights into the role of neutral and charged oxygen vacancies in conduction filament (CF) formation and rupture, which are demonstrated using the atomistic simulation based on density functional theory (DFT). Formation energy demonstrated that the fourfold coordinated oxygen vacancy is more stable. In addition, the electronic properties of the defect included supercell confirm the improvement in electrical conductivity due to the presence of additional energy states near Fermi energy. The CF formation and rupture using threefold and fourfold oxygen vacancies are demonstrated through cohesive energy, electron localization function, and band structure. Cohesive energy analysis confirms the cohesive nature of neutral oxygen vacancies while the isolated behavior for +2 charged oxygen vacancies in the CF. In addition, nudged elastic band calculation is also performed to analyze the oxygen vacancy diffusion energy under different paths. Moreover, we have computed the diffusion coefficient and drift velocity of oxygen vacancies to understand the CF. This DFT study described detailed insight into filamentary type resistive switching observed in the experimentally fabricated device. Therefore, this fundamental study provides the platform to explore the switching mechanism of other oxide materials used for memristor device application.

Comparison of the effect of removing bandage contact lens on the days 3 and 5 following photorefractive keratectomy.

AIM: To compare the outcomes of removing bandage contact lens (BCL) on days 3 and 5 after photorefractive keratectomy (PRK). METHODS: One hundred patients who underwent PRK (a total of 200 eyes) were enrolled in the present study. The subjects were assigned to two groups. Group 1 consisted of the right eyes of subjects and bandage contact lenses removal were on the 3rd day; Group 2 consisted of the fellow eyes of same subjects and removed bandage contact lenses on the 5th day after PRK. Then, data obtained from both groups were compared. To evaluate complications, the subjects underwent a slit-lamp examination in all visits. RESULTS: Filamentary keratitis was observed in one eye in both groups. The frequency of haze was higher in group 1; however, it was not significant between the two groups. Using mixed model analysis, significant differences were observed in the rate of complications as well as pain and eye discomfort scores between the groups (P < 0.05). No major complication was reported. CONCLUSION: Majority of post-PRK corneal epithelial defect is healed on day 3. However, keeping BCL for 5 days postoperatively instead of the three days produces a slightly lower rate of total complication.

Non-infectious and non-hereditary diseases of the corneal epithelium.

The corneal epithelium serves as a physical barrier and a refractive element. Therefore, diseases of the corneal epithelium can increase the risk for infection and causes vision loss. The corneal epithelium can be affected by a multitude of conditions, such as infections, hereditary diseases, depositions, trauma, autoimmune conditions, factitious disorders, and iatrogenic causes. Non-infectious and non-hereditary corneal epithelial diseases represent a collection of conditions with diverse etiologies and clinical presentations but similar patient symptoms. The differing therapeutic interventions for each condition make clinical distinction important. The clinical characteristics, disease course, pathophysiology and current treatments for non-infectious, non-hereditary corneal epithelial diseases are reviewed.

Coherent array of branched filamentary scales along the wing margin of a small moth.

In butterflies and moths, the wing margins are fringed with specialized scales that are typically longer than common scales. In the hindwings of some small moths, the posterior margins are fringed with particularly long filamentary scales. Despite the small size of these moth wings, these scales are much longer than those of large moths and butterflies. In the current study, photography of the tethered flight of a small moth, Phthorimaea operculella, revealed a wide array composed of a large number of long filamentary scales. This array did not become disheveled in flight, maintaining a coherent sheet-like structure during wingbeat. Examination of the morphology of individual scales revealed that each filamentary scale consists of a proximal stalk and distal branches. Moreover, not only long scales but also shorter scales of various lengths were found to coexist in each small section of the wing margin. Scale branches were ubiquitously and densely distributed within the scale array to form a mesh-like architecture similar to a nonwoven fabric. We propose that possible mechanical interactions among branched filamentary scales, mediated by these branches, may contribute to maintaining a coherent sheet-like structure of the scale array during wingbeat.

A 250 mV Cu/SiO2/W Memristor with Half-Integer Quantum Conductance States.

Memristive devices, whose conductance depends on previous programming history, are of significant interest for building nonvolatile memory and brain-inspired computing systems. Here, we report half-integer quantized conductance transitions G = (n/2) (2e(2)/h) for n = 1, 2, 3, etc., in Cu/SiO2/W memristive devices observed below 300 mV at room temperature. This is attributed to the nanoscale filamentary nature of Cu conductance pathways formed inside SiO2. Retention measurements also show spontaneous filament decay with quantized conductance levels. Numerical simulations shed light into the dynamics underlying the data retention loss mechanisms and provide new insights into the nanoscale physics of memristive devices and trade-offs involved in engineering them for computational applications.

Filamentary keratitis: A review.

Filamentary keratitis (FK) is a clinical sign of underlying ocular and systemic conditions. FK can cause significant irritation, tearing, and photophobia in the eye. It is a refractory debilitating condition caused by dry eye that affects the day-to-day activities of patients. The etiopathogenesis of FK is not well known; there are numerous predisposing causes. The condition starts as a sub-epithelial or Bowman's membrane dysfunction and leads to the shedding of epithelial cells that take a strand-like form and attach to the cornea. These strands are surrounded by mucin and continue to elongate to become filaments. The filament formation is further aided by the shearing action caused by eyelid movements. Several management approaches, such as addressing the underlying causes of filamentary keratitis, administering copious lubricants, topical corticosteroids, mucolytic agents, bandage contact lenses, punctal plugs, and mechanical removal of filaments are available. The prognosis is fair, and most cases resolve with occasional recurrences. Traditionally FK has been treated with lubricants, mechanical removal, and bandage contact lenses. The newer treatments are topical immunomodulators especially that treat filamentary keratitis associated with aqueous deficient dry eye. The review describes the treatment as well as pathogenesis.

Wearable filamentary continuous sensor for interstitial glucose detection in diabetes management.

The development of novel diabetes monitoring sensors is important for the diabetes management of millions of diabetic patients. This work reports a flexible filamentary continuous glucose monitoring (CGM) sensor. A multilayer CGM sensor has been constructed on titanium filament with low cost and ease of use. The sensor, made of flexible material, offers better adaptability and comfort than traditional rigid filament CGM sensors, allowing continuous monitoring of subcutaneous blood glucose levels to provide patients with treatment strategies. The performance and reliability of the sensor were verified through rat experiments. The trend of the increase and decrease of the detected current was generally consistent with the actual blood glucose, and the detected values were located in regions A and B of the Clarke error grid. The results show that the sensor has the advantages of high sensitivity, high accuracy and fast response speed, which is suitable for monitoring the blood glucose level for a long time and has a broad application prospect in diabetes monitoring, exercise monitoring, health management and clinical application.

Resistive Memory-Switching Behavior in Solution-Processed Trans, trans-1,4-bis-(2-(2-naphthyl)-2-(butoxycarbonyl)-vinyl) Benzene-PVA-Composite-Based Aryl Acrylate on ITO-Coated PET.

Resistive switching memories are among the emerging next-generation technologies that are possible candidates for in-memory and neuromorphic computing. In this report, resistive memory-switching behavior in solution-processed trans, trans-1,4-bis-(2-(2-naphthyl)-2-(butoxycarbonyl)-vinyl) benzene-PVA-composite-based aryl acrylate on an ITO-coated PET device was studied. A sandwich configuration was selected, with silver (Ag) serving as a top contact and trans, trans-1,4-bis-(2-(2-naphthyl)-2-(butoxycarbonyl)-vinyl) benzene-PVA-composite-based aryl acrylate and ITO-PET serving as a bottom contact. The current-voltage (I-V) characteristics showed hysteresis behavior and non-zero crossing owing to voltages sweeping from positive to negative and vice versa. The results showed non-zero crossing in the devices' current-voltage (I-V) characteristics due to the nanobattery effect or resistance, capacitive, and inductive effects. The device also displayed a negative differential resistance (NDR) effect. Non-volatile storage was feasible with non-zero crossing due to the exhibition of resistive switching behavior. The sweeping range was -10 V to +10 V. These devices had two distinct states: 'ON' and 'OFF'. The ON/OFF ratios of the devices were 14 and 100 under stable operating conditions. The open-circuit voltages (Voc) and short-circuit currents (Isc) corresponding to memristor operation were explained. The DC endurance was stable. Ohmic conduction and direct tunneling mechanisms with traps explained the charge transport model governing the resistive switching behavior. This work gives insight into data storage in terms of a new conception of electronic devices based on facile and low-temperature processed material composites for emerging computational devices.

The Role of Polymers in Halide Perovskite Resistive Switching Devices.

Currently, halide perovskites (HPs) are gaining traction in multiple applications, such as photovoltaics and resistive switching (RS) devices. In RS devices, the high electrical conductivity, tunable bandgap, good stability, and low-cost synthesis and processing make HPs promising as active layers. Additionally, the use of polymers in improving the RS properties of lead (Pb) and Pb-free HP devices was described in several recent reports. Thus, this review explored the in-depth role of polymers in optimizing HP RS devices. In this review, the effect of polymers on the ON/OFF ratio, retention, and endurance properties was successfully investigated. The polymers were discovered to be commonly utilized as passivation layers, charge transfer enhancement, and composite materials. Hence, further HP RS improvement integrated with polymers revealed promising approaches to delivering efficient memory devices. Based on the review, detailed insights into the significance of polymers in producing high-performance RS device technology were effectively understood.

Ion microsource integrated with scanning electron microscope for sample preparation.

The authors developed the Ar+ ion microsource, which can generate a filamentary ion beam of a few tens of µm at its half-power diameter with a target current up to 50 µA at - 4 kV extracting voltage. This comprises a ceramic discharge capillary of 1 mm in inner diameter and 10 mm long with a very small copper anode and a cathode outlet aperture of 0.5 mm in diameter at its ends. The arrangement has been examined in three alternative designs equipped with cathodes of different shapes and materials and two extraction voltage supply schemes, i.e., with the negatively biased sample and the earthed cathode or the earthed sample and the cathode at a floating positive potential (recommended solution). Numerous other factors were considered that can affect the standard SEM operation, such as excessive working gas leakage and jamming with discharge interferences, e.g., streamers. The microsource makes a compact structure that can be positioned above the sample inside a standard SEM without any changes to its original structure and collisions with standard modes of the SEM operation. Such a tool enables the removal of target microvolumes in chosen places, so it can be used for some technological purposes, such as making small apertures. However, its main goal is to uncover the bulk internal structure of the specimen, imaging it in a 3D form. Therefore, the microsource is placed on the movable arm and coupled with the semiconductor four-quadrant backscattered electron (BSE) detector, which enables 3D imaging of the uncovered structure with the multidetector method. This implies taking in one scan a set of images from four or five directions, using both material- and topography-sensitive channels of information (BSE and secondary electron SE), which facilitates their interpretation.

Recent Advances in Cerium Oxide-Based Memristors for Neuromorphic Computing.

This review article attempts to provide a comprehensive review of the recent progress in cerium oxide (CeO2)-based resistive random-access memories (RRAMs). CeO2 is considered the most promising candidate because of its multiple oxidation states (Ce3+ and Ce4+), remarkable resistive-switching (RS) uniformity in DC mode, gradual resistance transition, cycling endurance, long data-retention period, and utilization of the RS mechanism as a dielectric layer, thereby exhibiting potential for neuromorphic computing. In this context, a detailed study of the filamentary mechanisms and their types is required. Accordingly, extensive studies on unipolar, bipolar, and threshold memristive behaviors are reviewed in this work. Furthermore, electrode-based (both symmetric and asymmetric) engineering is focused for the memristor's structures such as single-layer, bilayer (as an oxygen barrier layer), and doped switching-layer-based memristors have been proved to be unique CeO2-based synaptic devices. Hence, neuromorphic applications comprising spike-based learning processes, potentiation and depression characteristics, potentiation motion and synaptic weight decay process, short-term plasticity, and long-term plasticity are intensively studied. More recently, because learning based on Pavlov's dog experiment has been adopted as an advanced synoptic study, it is one of the primary topics of this review. Finally, CeO2-based memristors are considered promising compared to previously reported memristors for advanced synaptic study in the future, particularly by utilizing high-dielectric-constant oxide memristors.

A review of filamentary keratitis.

Filamentary keratitis (FK) is characterized by the presence of filaments on the corneal surface that are often associated with symptoms of foreign body sensation, irritation, and eye pain. FK is associated with a variety of ocular and systemic conditions, most notably dry eye disease. These filaments are composed primarily of epithelium, mucus, and cellular debris; however, their pathogenesis remains an area of debate. Aggravating factors for FK include desiccation, inflammatory mediators, as well as eyelid mechanical forces. Management consists of addressing associated conditions, especially dry eye disease, and providing medical and procedural treatments to alleviate symptoms and restore the ocular surface. Mainstay treatments include filament removal, increased lubrication with artificial tears and punctal occlusion, hypertonic saline, antiinflammatory and mucolytic medications, and autologous serum eye drops, as well as bandage contact lenses. A stepwise approach is required to manage patients with acute or chronic FK. Prolonged therapy is often necessary to prevent recurrence of this bothersome condition.

Therapeutic Effect of Intense Pulsed Light in Patients with Sjögren's Syndrome Related Dry Eye.

This prospective randomized study evaluated the efficacy and safety of intense pulsed light (IPL) and meibomian gland expression (MGX) as polytherapy for Sjögren's Syndrome-related dry eye (SS-DE). The study enrolled 55 participants with SS-DE, 27 for the treatment group and 28 for the control group. The treatment group underwent three IPL-MGX treatments, three weeks apart. A randomly-selected eye from each patient was assessed at baseline and on weeks 9, 12, and 15 for Snellen best-corrected visual acuity (BCVA), intraocular pressure, Ocular Surface Disease Index (OSDI) score, conjunctival congestion, tear meniscus height, non-invasive tear breakup time (NBUT), Schirmer's I test (SIT), corneal fluorescein staining (CFS), meibomian gland (MG) dropout, eyelid margin abnormality, MGX and meibum quality. OSDI, NBUT, CFS, MGX, and meibum quality were significantly improved in both groups, particularly in the treatment group. The eyelid margin abnormality improved significantly in the treatment but not in the control group on weeks 12 and 15. Snellen BCVA, conjunctival congestion, and SIT improved significantly in the treatment group, but the two groups were statistically similar. Our results indicated that three IPL-MGX sessions could significantly improve the subjective and objective characteristics of SS-DE, representing a promising treatment strategy.

Electroforming-Free Bipolar Resistive Switching Memory Based on Magnesium Fluoride.

Electroforming-free resistive switching random access memory (RRAM) devices employing magnesium fluoride (MgFx) as the resistive switching layer are reported. The electroforming-free MgFx based RRAM devices exhibit bipolar SET/RESET operational characteristics with an on/off ratio higher than 102 and good data retention of >104 s. The resistive switching mechanism in the Ti/MgFx/Pt devices combines two processes as well as trap-controlled space charge limited conduction (SCLC), which is governed by pre-existing defects of fluoride vacancies in the bulk MgFx layer. In addition, filamentary switching mode at the interface between the MgFx and Ti layers is assisted by O-H group-related defects on the surface of the active layer.

Nanoscale Superconducting States in the Fe-Based Filamentary Superconductor of Pr-Doped CaFe2As2.

The low-temperature scanning tunneling microscope and spectroscopy (STM/STS) are used to visualize superconducting states in the cleaved single crystal of 9% praseodymium-doped CaFe2As2 (Pr-Ca122) with Tc ≈ 30 K. The spectroscopy shows strong spatial variations in the density of states (DOS), and the superconducting map constructed from spectroscopy discloses a localized superconducting phase, as small as a single unit cell. The comparison of the spectra taken at 4.2 K and 22 K (below vs. close to the bulk superconducting transition temperature) from the exact same area confirms the superconducting behavior. Nanoscale superconducting states have been found near Pr dopants, which can be identified using dI/dV conductance maps at +300 mV. There is no correlation of the local superconductivity to the surface reconstruction domain and surface defects, which reflects its intrinsic bulk behavior. We, therefore, suggest that the local strain of Pr dopants is competing with defects induced local magnetic moments; this competition is responsible for the local superconducting states observed in this Fe-based filamentary superconductor.

Insights into Multilevel Resistive Switching in Monolayer MoS2.

The advent of two-dimensional materials has opened a plethora of opportunities in accessing ultrascaled device dimensions for future logic and memory applications. In this work, we demonstrate that a single layer of large-area chemical vapor deposition-grown molybdenum disulfide (MoS2) sandwiched between two metal electrodes can be tuned to show multilevel nonvolatile resistive memory states with resistance values separated by 5 orders of magnitude. The switching process is unipolar and thermochemically driven requiring significant Joule heating in the reset process. Temperature-dependent electrical measurements coupled with semiclassical charge transport models suggest that the transport in these devices varies significantly in the initial (pristine) state, high resistance state, and low resistance state. In the initial state, the transport is a one-step direct tunneling (at low voltage biases) and Fowler Nordeim tunneling (at higher bias) with an effective barrier height of 0.33 eV, which closely matches the Schottky barrier at the MoS2/Au interface. In the high resistive state, trap-assisted tunneling provides a reasonable fit to experimental data for a trap height of 0.82 eV. Density functional theory calculations suggest the possibility of single- and double-sulfur vacancies as the microscopic origins of these trap sites. The temperature-dependent behavior of the set and reset process are explained by invoking the probability of defect (sulfur vacancy) creation and mobility of sulfur ions. Finally, conductive atomic force microscopy measurements confirm that the multifilamentary resistive memory effects are inherent to a single-crystalline MoS2 triangle and not necessarily dependent on grain boundaries. The insights suggested in this work are envisioned to open up possibilities for ultrascaled, multistate, resistive memories for next-generation digital memory and neuromorphic applications.

Oral guaifenesin for treatment of filamentary keratitis: A pilot study.

PURPOSE: Pilot study to evaluate the safety and efficacy of oral guaifenesin in reducing the signs and symptoms of filamentary keratitis. METHODS: Prospective, uncontrolled open-label pilot study. Twelve patients with non-Sjögren dry eye disease (DED) and secondary filamentary keratitis received treatment with oral guaifenesin 600 mg twice a day (total dose of 1.2 g/day) for 4 weeks. Adverse events, change in the number of corneal filaments, corneal fluorescein staining (CFS; NEI grading system), and symptoms (Ocular Surface Disease Index) were assessed. RESULTS: Before starting oral guaifenesin, all patients were on topical medical therapy for their condition. At baseline, the mean number of filaments was 5.8 ±â€¯2.9, CFS score 7.3 ±â€¯3.2, and OSDI score 55.6 ±â€¯25. After 4 weeks of treatment, the number of filaments was 2.1 ±â€¯2.2 (p = 0.04 vs. baseline), CFS score 6.5 ±â€¯3.1 (p = 0.5), and OSDI score 46.1 ±â€¯30.9 (p = 0.2). One patient discontinued the medication due to gastrointestinal side effects. CONCLUSIONS: Oral guaifenesin was safe and generally well tolerated, and demonstrated modest efficacy in reducing the severity of filamentary keratitis. These results should be considered preliminary; however, placebo-controlled investigations would be justified to evaluate the therapeutic efficacy of oral guaifenesin as a mucolytic in treatment of filamentary keratitis.

Ocular-muscle surgery for filamentary keratitis that developed in double elevator palsy.

PURPOSE: To report a case of filamentary keratitis occurring in the cornea hidden under the eyelids by squint surgery. METHODS: A 69-year-old female patient with a history of amblyopia was referred for intractable filamentary keratitis in the left eye. The strabismus angle was 35Δ hypertrophic, and ocular motility was within the normal range. Slit-lamp examination of her left eye revealed filamentary keratitis in more than one-third of the upper cornea behind the upper eyelid. Her right eye was diagnosed as supranuclear double elevator palsy. We performed strabismus surgery on her right eye, including inferior rectus muscle recession (5 mm) in combination with superior rectus muscle resection (5 mm) under local anesthesia. Following surgery, the left eye squint angle was improved. The filamentary keratitis of the left eye disappeared, and there was no recurrence over the following 5 years. CONCLUSION: The squint surgery of paralyzed right eye decreased the strabismus angle, subsequently resulting in the disappearance of the filamentary keratitis in the left eye via the resolution of the relative blepharoptosis. Although the squint operation performed was not for the purpose of improving binocular function, we want to conclude that it can treat the filamentary keratitis behind the eyelid.