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Background: Hydrophilic intraocular lens opacification is a rare complication due to calcification. With current new surgical techniques, including lamellar endothelial keratoplasty and vitrectomies, this irreversible complication is becoming more common. In this case study, we present clinical and laboratory features of a case of Carlevale hydrophilic acrylic IOL calcification., Case Presentation: Observational case report of a single incident case. An 83-year-old man was referred to our ophthalmic department complaining of right eye vision blurring for six months. Slit-lamp biomicroscopy revealed IOL opacification. Deposits of calcium phosphate were found both on the IOL's surface and inside it, according to thorough investigation using optical, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectrometry., Conclusions: To the best of our knowledge, this is the first case to describe the laboratory evidence of Carlevale hydrophilic IOL calcification, suggesting possible explanation mechanisms based on underlying pathology and surgical technique. It reminds us that these findings suggest that physicians should be aware of possible hydrophilic IOL calcification., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Dexamethasone intravitreal implant (Ozurdex ® ; Allergan, Inc., CA, USA) has been proved to be effective in a variety of clinical settings including cases of pseudophakic cystoid macular edema. Uncommonly, this implant can migrate from the vitreous cavity and into the anterior chamber, especially in vitrectomized eyes with lens capsule defects. We report herein a rare case of anterior chamber migration and illustrate the passageway of the dexamethasone intravitreal implant through a new type of scleral fixated lens, the Carlevale IOL (Soleko-Italy). A 78-year-old woman was left aphakic following a complicated right eye hypermature cataract surgery with posterior capsule rupture and zonular dehiscence. Shortly thereafter, she underwent a planned combined pars plana vitrectomy with the placement of a Carlevale sutureless scleral fixated intraocular lens for the treatment of her aphakia. Due to a subsequent persistent cystoid macular edema that was unresponsive to topical treatment and sub-tenon corticosteroids, an intravitreal dexamethasone implant was injected. Eleven days after implantation, the patient presented with a floating implant in the anterior chamber and corneal edema. Following an immediate surgical removal, corneal edema resolved and visual acuity improved. One year later, results remain stable without macular edema recurrence. Anterior chamber migration of the Ozurdex implant is a potential complication in vitrectomized eyes, even when new types which are larger and specially designed for scleral fixation intraocular lenses are utilized. Corneal complications can be reversible following an immediate removal of the implant., Competing Interests: The authors have no financial disclosures (P.S., P.G., S.T., E.C., E.M., and E.K.)., (© 2023 The Author(s). Published by S. Karger AG, Basel.)

Purpose: The purpose of the study is to evaluate the comparability of corneal power measurements, anterior chamber depth (ACD), and white-to-white (WTW) distance between a high-resolution Scheimpflug-based tomography (Pentacam HR; Oculus GmbH, Wetzlar, Germany) and a swept-source optical biometry, IOL Master 700; Carl Zeiss Meditec AG, Jena, Germany) in patients having undergone a myopic refractive surgery., Methods: This prospective, interinstrument reliability analysis included 31 individuals with a previous myopic laser refractive correction. Standard keratometry and total keratometry (TK) of the flattest and steepest axis of the IOL Master 700 were compared with standard keratometry (simulated keratometry [SimK]), true net power (TNP), equivalent keratometer readings (EKR), and total corneal refractive power of the Pentacam. The Bland-Altman analysis evaluated the agreement between the measurements of both devices. A paired t -test was performed to compare the mean values of the variables obtained by the two devices., Results: Mean age of the participants was 31.87 ± 13.17 years. Ten patients (32.3%) had undergone laser in situ keratomileusis surgery, and 21 (67.7%) had undergone photorefractive keratectomy surgery. The two devices generated statistically significant differences in almost all the comparisons between their corneal keratometry values, ACD, and WTW. The two devices agreed in some of the flat axis values and more specifically on SimK1 and K1, EKR K1 along 1 mm-zone and K1, as well as on the comparison between the EKR keratometry values along 1, 2, and 3 mm-zone with their corresponding TKs., Conclusion: IOL Master 700 and Pentacam HR do not show good concordance and cannot be used interchangeably when measuring keratometry values in postrefractive eyes, rendering the IOL power calculation in postrefractive eyes really challenging., Competing Interests: There are no conflicts of interest., (Copyright: © 2022 Saudi Journal of Ophthalmology.)

Background: Cataract surgery in keratoconic patients is challenging because of the corneal distortion, which can lead to inaccurate keratometry readings. This study is a comparison of the accuracy of keratometry readings by two types of devices in a tertiary hospital., Purpose: To evaluate the comparability of corneal power measurements, anterior chamber depth (ACD), and white-to-white (WTW) distance between Scheimpflug-based tomography (Pentacam AXL; OCULUS GmbH, Wetzlar, Germany) and swept-source optical biometry (IOLMaster 700; Carl Zeiss Meditec AG, Jena, Germany) in patients with keratoconus., Methods: This pilot, prospective, interinstrument reliability study included 30 keratoconic eyes of 15 individuals who had not undergone any kind of corneal surgery. Standard K and total refractive power (TK ® ) of the flattest and steepest axes of the IOLMaster 700 were compared with the standard keratometry (SimK), true net power (TNP), equivalent keratometer readings (EKR), and total corneal refractive power (TCRP) of the Pentacam. The Bland-Altman analysis was used to evaluate the agreement between the measurements of both devices. The paired-samples t -test and the Wilcoxon signed-rank test were performed to compare the mean values of the variables obtained with the devices., Results: The K1 value of the IOLMaster 700 was significantly higher from EKR K1 along the 3-mm (mean difference: 0.79 diopters, p  = 0.01), 4-mm (mean difference: 1.01 D, p  = 0.01), and 4.5-mm zones (mean difference: 1.20 D, p  = 0.01) and TNP K1 along the 3-mm (mean difference: 0.88 D, p < 0.001) and 4-mm zones (mean difference: 0.97 D, p < 0.001). The TK1 value was significantly higher from EKR K1 along the 2-mm (mean difference: 0.42 D, p  = 0.04), 3-mm (mean difference: 0.83 D, p  = 0.003), 4-mm (mean difference: 1.05 D, p  = 0.004), and 4.5-mm zones (mean difference: 1.24 D, p  = 0.005) and TNP K1 along the 3-mm (mean difference: 0.92 D, p < 0.001) and 4-mm zones (mean difference: 1.01 D, p < 0.001). The K2 value of the IOLMaster 700 was significantly higher from TK2 (mean difference: 0.11 D, p  = 0.04) and all the corresponding variables of the Pentacam device. The TK2 value was significantly higher from all the corresponding variables of the Pentacam device. The Pentacam also yielded significantly lower values for the WTW distance (mean difference: 0.31 mm, p < 0.001) and no significant difference in terms of ACD values ( p  = 0.9)., Conclusion: The IOLMaster measured significantly greater keratometry readings in the steep axis for all the variables studied. The keratometry and WTW measurements of the investigated devices cannot be used interchangeably in keratoconus., Competing Interests: Conflict of interest statement: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s), 2022.)

Imaginary-time time-dependent density functional theory (it-TDDFT) has been proposed as an alternative method for obtaining the ground state within density functional theory (DFT) which avoids some of the difficulties with convergence encountered by the self-consistent-field (SCF) iterative method. It-TDDFT was previously applied to clusters of atoms where it was demonstrated to converge in select cases where SCF had difficulty with convergence. In the present work we implement it-TDDFT propagation for periodic systems by modifying the Quantum ESPRESSO (QE) package, which uses a plane-wave basis with multiple k points, and has the options of non-collinear and DFT + U calculations using ultra-soft or norm-conserving pseudo potentials. We demonstrate that our implementation of it-TDDFT propagation with multiple k points is correct for DFT + U non-collinear calculations and for DFT + U calculations with ultra-soft pseudo potentials. Our implementation of it-TDDFT propagation converges to the exact SCF energy (up to the decimal guaranteed by double precision) in all but one case where it converged to a slightly lower value than SCF, suggesting a useful alternative for systems where SCF has difficulty reaching the Kohn-Sham (KS) ground state. In addition, we demonstrate that more rapid convergence can be achieved if we use adaptive-size imaginary-time-steps for different kinetic-energy plane-waves., (© 2020 IOP Publishing Ltd.)

We study the topological states which appear at the interface between a topological insulator (TI) and a conventional insulator (CI) using effective Hamiltonians which accurately describe the band structure of the Bi 2 Se 3 family. Due to the hybridization between the TI and the CI states, the band-gap that appears in the interface Dirac cone decreases and ultimately vanishes by tuning the interface-hopping amplitude or by selecting a CI of appropriate band effective mass. More importantly, we find that a topologically trivial TI slab can be made non-trivial and vice-versa by tuning of such an interface-hopping amplitude or by tuning the CI band effective-mass; namely, a topological phase transition can be induced in such heterostructures indicated by the presence or absence of gapless linear edge modes. We discuss the relevance and realization of our results and conclusions in future experiments.

A mechanism for multiple carrier generation through impact ionization (IA) proposed earlier for bulk systems of strongly correlated insulators is generalized to the case of conventional insulators that contain localized bands a few eV above and below the highest occupied band. Specifically, we study the case of hybridization of localized orbitals with more dispersive bands near the Fermi level, where the generated multiple carriers, which ultimately decay to the edges of the dispersive bands by means of IA processes, acquire lighter mass and this could allow their more efficient separation before recombination. We argue that this may be applicable to the case of halide perovskites and it could be one of the reasons for their observed photovoltaic efficiency. We discuss the criteria one should use to uncover the appropriate material in order to harvest the optimum effect of IA for the spectrum of the solar photon energy distribution.

Reliable and robust convergence to the electronic ground state within density functional theory (DFT) Kohn-Sham (KS) calculations remains a thorny issue in many systems of interest. In such cases, charge sloshing can delay or completely hinder the convergence. Here, we use an approach based on transforming the time-dependent DFT equations to imaginary time, followed by imaginary-time evolution, as a reliable alternative to the self-consistent field (SCF) procedure for determining the KS ground state. We discuss the theoretical and technical aspects of this approach and show that the KS ground state should be expected to be the long-imaginary-time output of the evolution, independent of the exchange-correlation functional or the level of theory used to simulate the system. By maintaining self-consistency between the single-particle wave functions (orbitals) and the electronic density throughout the determination of the stationary state, our method avoids the typical difficulties encountered in SCF. To demonstrate dependability of our approach, we apply it to selected systems which struggle to converge with SCF schemes. In addition, through the van Leeuwen theorem, we affirm the physical meaningfulness of imaginary-time TDDFT, justifying its use in certain topics of statistical mechanics such as in computing imaginary-time path integrals.

: Several researchers have assessed the utility of Impulse Oscillometry System (IOS) in diagnosing and evaluating the severity of respiratory diseases in childhood, but none has investigated the impact of the fluctuations of IOS parameters in an individualized manner. In this two-year prospective study, we aimed to longitudinally evaluate changes in airflow limitation and bronchodilator responsiveness in steroid-naïve four- to six-year-old children during a virus-induced wheezing episode, with IOS pulmonary resistance parameters set at 5 (R5) and 20 (R20) Hz. Moreover, feasibility and reproducibility, in addition to the diagnostic properties of these parameters were examined. Lung function was assessed every six weeks (baseline), within the first 48 hours following an acute wheezing episode (Day 0), after 10, and after 30 days. Forty-three out of 93 recruited children (4.5 ± 0.4 years old) experienced a wheezing episode during the study period. All children were able to perform the IOS effort in an acceptable and highly reproducible manner. R5 and R20 fluctuated independently of atopy, age, height, and weight. On Day 0, R5 values were significantly lower than the respective baseline values and returned to individual baseline levels within 10 days. Post-bronchodilation R5 values were similar to the baseline ones, reflecting a reversible airway obstruction on Day 0. Response to bronchodilation (ΔR5) was significantly more pronounced on Day 0. ΔR5 values lower than -20.5% had a sensitivity of 70% and a specificity of 76% and could accurately identify up to 75% of the examined preschoolers. This study provides evidence in favor of the objective utility of IOS as an easy, highly reproducible, and sensitive technique to assess clinically significant fluctuations and bronchodilation responses suggestive of airflow limitation. Reference values although necessary are suboptimal, utilizing the personal best values as personal reference is useful and reliable., Competing Interests: The authors declare no conflict of interest.

Background: Data on the prevalence and clinical course of food protein-induced enterocolitis syndrome (FPIES) vary between populations and according to the culprit food., Objective: To evaluate the incidence, clinical characteristics, and remission patterns of FPIES among children in a Greek pediatric allergy referral center., Methods: We retrospectively studied children with acute FPIES. Data on age, sex, type of reaction, the implicated food, and oral food challenge (OFC) outcomes at baseline and upon reevaluation were analyzed., Results: Between October 2010 and March 2017, 72 (38 males) out of 15,114 subjects who had been referred to our department due to any reported allergic symptoms were diagnosed with acute FPIES. The most commonly implicated foods were cow's milk (CM) (45.8%), fish (34.7%), rice (9.7%), egg (6.9%), and chicken (2.8%). The mean age at diagnosis was 7.1/19.3/9.1/18.7/8.7 months for those with CM/fish/rice/egg/chicken FPIES, respectively. Sixty-nine OFCs were performed, of which 8 were diagnostic and 61 for tolerance evaluation. The type of culprit food was significantly associated with the outcome of the tolerance OFCs. OFCs to fish resulted positive at a significantly higher rate (12/22; 54.5%) than OFCs to CM (4/29; 13.7%), rice (1/5; 20%), egg (0/3; 0%), and chicken (0/2; 0%) (p = 0.01). The time period between diagnosis and tolerance acquisition was prolonged in the fish FPIES cases (74.8 months; 95% CI: 57.9-91.6) compared to that with other foods such as CM (20.7 months; 95% CI: 17.3-24.1), rice (31.8 months; 95% CI: 21.9-41.7), and egg (24.3 months; 95% CI: 10.7-37.9), as shown in a Kaplan-Meier analysis (log-rank, p < 0.001). When the fish FPIES children were assessed for tolerance, OFCs were significantly more often positive than in CM FPIES children (52 vs. 18.1%; p = 0.03), despite the fact that the children were challenged at an older age (fish: 70.4 months, 95% CI: 58.3-82.5, vs. CM: 26.57 months, 95% CI: 21.1-32, p < 0.001)., Conclusions: Acute FPIES had a low incidence in our population. CM and fish were the two most frequent elicitors. Significantly delayed presentation and prolonged remission was noted for FPIES caused by fish., (© 2019 S. Karger AG, Basel.)

Background: Atopic dermatitis (AD) and chronic spontaneous urticaria (CSU) represent two of the most common chronic inflammatory pruritic skin diseases. Any relationship between atopic skin disorders and CSU is controversial, mostly due to the paucity of relevant epidemiologic and pathogenetic data. Objective: To evaluate whether a history of AD in early childhood represents a risk factor for the subsequent occurrence of CSU in a pediatric population. Methods: Retrospective data of new cases of patients who visited the outpatient allergy unit of a tertiary pediatric hospital in Athens, Greece, between June 2014 and August 2016, were analyzed. Diagnoses of CSU and AD were based on diagnostic criteria proposed by the European Academy of Allergy and Clinical Immunology and the Hanifin and Rajka criteria, respectively. The data analyzed included CSU and AD diagnoses and the association with gender and season of birth as well as a personal and family history of allergy-related diseases (e.g., asthma, allergic rhinitis, AD, and food and drug allergies). Results: Records from 2261 children were included in the analysis (1365 boys; mean ± standard deviation [SD] age, 8.7 ± 5.8 years). Fifty-one children (31 boys; mean ± SD age, 9.1 ± 4.6 years) were diagnosed with CSU, whereas AD was reported in 761 children (466 boys; mean ± SD age, 5.2 ± 3.8 years). Multivariate data analysis showed that the children with a history of an early diagnosis of AD were at increased risk for later CSU occurrence (odds ratio 2.923 [95% confidence interval, 1.647-5.189], p < 0.001). No significant associations were observed with respect to other demographic and atopy-associated characteristics of the patients. Conclusion: Results of our study indicated that AD may constitute an important risk factor to the subsequent occurrence of CSU. This notion warrants further study with well-designed prospective cohorts.

In ReS2, a layer-independent direct band gap of 1.5 eV implies a potential for its use in optoelectronic applications. ReS2 crystallizes in the 1T'-structure, which leads to anisotropic physical properties and whose concomitant electronic structure might host a nontrivial topology. Here, we report an overall evaluation of the anisotropic Raman response and the transport properties of few-layered ReS2 field-effect transistors. We find that ReS2 exfoliated on SiO2 behaves as an n-type semiconductor with an intrinsic carrier mobility surpassing μ(i) ∼ 30 cm(2)/(V s) at T = 300 K, which increases up to ∼350 cm(2)/(V s) at 2 K. Semiconducting behavior is observed at low electron densities n, but at high values of n the resistivity decreases by a factor of >7 upon cooling to 2 K and displays a metallic T(2)-dependence. This suggests that the band structure of 1T'-ReS2 is quite susceptible to an electric field applied perpendicularly to the layers. The electric-field induced metallic state observed in transition metal dichalcogenides was recently claimed to result from a percolation type of transition. Instead, through a scaling analysis of the conductivity as a function of T and n, we find that the metallic state of ReS2 results from a second-order metal-to-insulator transition driven by electronic correlations. This gate-induced metallic state offers an alternative to phase engineering for producing ohmic contacts and metallic interconnects in devices based on transition metal dichalcogenides.

The diagrammatic Monte Carlo (DiagMC) method is a numerical technique which samples the entire diagrammatic series of the Green's function in quantum many-body systems. In this work, we incorporate the flat histogram principle in the diagrammatic Monte Carlo method, and we term the improved version the "flat histogram diagrammatic Monte Carlo" method. We demonstrate the superiority of this method over the standard DiagMC in extracting the long-imaginary-time behavior of the Green's function, without incorporating any a priori knowledge about this function, by applying the technique to the polaron problem.

Background: It is disputed whether recurrent episodes of wheeze in preschool-aged children comprise a distinct asthma phenotype., Objective: We sought to prospectively assess airflow limitation and airway inflammation in children 4 to 6 years old with episodic virus-induced wheeze., Methods: Ninety-three children 4 to 6 years old with a history of mild, virus-induced episodes of wheeze who were able to perform acceptable fraction of exhaled nitric oxide (Feno) maneuvers and spirometry (with forced expiratory time ≥0.5 seconds) were followed prospectively. Lung function and Feno values were measured every 6 weeks (baseline) within the first 48 hours of an acute wheezing episode (day 0) and 10 and 30 days later. Symptom scores and peak flow measurement were recorded daily., Results: Forty-three children experienced a wheezing episode. At day 0, Feno values were significantly increased, whereas forced expiratory volume at 0.5 seconds (FEV(0.5)) significantly decreased compared with baseline (16 ppb [interquartile range {IQR}, 13-20 ppb] vs 9 ppb IQR, 7-11 ppb] and 0.84 L [IQR, 0.75-0.99 L] vs 0.99 L [IQR, 0.9-1.07 L], respectively; both P < .001). Airflow limitation at day 0 was reversible after bronchodilation. FEV(0.5) and Feno values were significantly associated with each other and with lower and upper respiratory tract symptoms when assessed longitudinally but not cross-sectionally at all time points independently of atopy. Feno and FEV(0.5) values returned to baseline levels within 10 days., Conclusions: Mild episodes of wheeze in preschoolers are characterized by enhanced airway inflammation, reversible airflow limitation, and asthma-related symptoms. Feno values increase significantly during the first 48 hours and return to personal baseline within 10 days from the initiation of the episode. Longitudinal follow-up suggests that symptoms, inflammation, and lung function correlate well in this phenotype of asthma., (Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)

We have carried out binocular rivalry experiments with a large number of subjects to obtain high quality statistics on probability distribution of dominance duration (PDDD) for two cases where (a) the rival stimulus is continuously presented and (b) the rival stimulus is periodically removed, with stimulus-on and stimulus-off intervals T(on) and T(off) respectively. In the present study we have chosen to study the regime of relatively long stimulus-on time, i.e., T(on)> 1s, where the stimulus presentation duration is significantly longer than the human reaction and recognition time. In the case of periodically removed stimulus, the total probability for percept reversal during each of the successive stimulus-on intervals T(on) can be predicted using the PDDD for continuous viewing. More importantly, this total probability for percept reversal during any stimulus-on interval is independent of the length T(off) of the preceding blank time, which can be quite long. We argue that this suggests that, in the regime of long T(on) and T(off) considered here, the variables representing the perceptual state do not change significantly during long blank intervals. We discuss that these findings impose challenges to theoretical models which aim at describing visual perception., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

On the basis of the general character and operation of the process of perception, a formalism is sought to mathematically describe the subjective or abstract/mental process of perception. It is shown that the formalism of orthodox quantum theory of measurement, where the observer plays a key role, is a broader mathematical foundation which can be adopted to describe the dynamics of the subjective experience. The mathematical formalism describes the psychophysical dynamics of the subjective or cognitive experience as communicated to us by the subject. Subsequently, the formalism is used to describe simple perception processes and, in particular, to describe the probability distribution of dominance duration obtained from the testimony of subjects experiencing binocular rivalry. Using this theory and parameters based on known values of neuronal oscillation frequencies and firing rates, the calculated probability distribution of dominance duration of rival states in binocular rivalry under various conditions is found to be in good agreement with available experimental data. This theory naturally explains an observed marked increase in dominance duration in binocular rivalry upon periodic interruption of stimulus and yields testable predictions for the distribution of perceptual alteration in time.

We describe the case of a 53-year-old man with a severely stenotic bicuspid aortic valve combined with an unruptured aneurysm of the left sinus of Valsalva and an aberrant left coronary artery. The patient was successfully treated with aortic valve replacement and closure of the aneurysm. It is well known that patients with a bicuspid aortic valve have an increased incidence of other congenital anomalies, but the combination presented in our case is very rare.

The two-dimensional electron gas (2DEG) in moderate magnetic fields in ultraclean AlAs-GaAs heterojunctions exhibits transport anomalies suggestive of a compressible anisotropic metallic state. Using scaling arguments and Monte Carlo simulations, we develop an order parameter theory of an electron nematic phase. The observed temperature dependence of the resistivity anisotropy behaves like the orientational order parameter if the transition to the nematic state occurs at a finite temperature T(c) approximately 65 mK, and is slightly rounded by a small background microscopic anisotropy. We propose a light scattering experiment to measure the critical susceptibility.