Effect of Ion Mass on Dynamic Correlations in Ionic Liquids

Ionic liquids (ILs) are a class of liquid salts with distinct properties such as high ionic conductivity, low volatility, and a broad electrochemical window, making them appealing for use in energy storage applications. The ion-ion correlations are some of the key factors that play a critical role in the ionic conductivity of ILs. In this work, we present the study of the impact of ion mass on ion-ion correlations in ILs, applying a combination of broadband dielectric spectroscopy measurements and molecular dynamics simulations. We examined three ILs with the same cation but different anions to consider three different cases of cation-anion masses: M+ > M-, M+ ≈ M-, and M+ < M-. We applied the momentum conservation approach to estimate the contribution of distinct ion-ion correlations from experimental data and obtained good agreement with direct calculations of distinct ion-ion correlations from molecular dynamics simulations. Our findings reveal that relative ion mass has a strong effect on the distinct ion-ion correlations, leading to swapping of the relative amplitude of distinct cation-cation and anion-anion correlations.

Prickle and Ror modulate Dishevelled-Vangl interaction to regulate non-canonical Wnt signaling during convergent extension

Convergent extension (CE) is a fundamental morphogenetic process where oriented cell behaviors lead to polarized extension of diverse tissues. In vertebrates, regulation of CE requires both non-canonical Wnt, its co-receptor Ror, and "core members" of the planar cell polarity (PCP) pathway. PCP was originally identified as a mechanism to coordinate the cellular polarity in the plane of static epithelium, where core proteins Frizzled (Fz)/ Dishevelled (Dvl) and Van Gogh-like (Vangl)/ Prickel (Pk) partition to opposing cell cortex. But how core PCP proteins interact with each other to mediate non-canonical Wnt/ Ror signaling during CE is not clear. We found previously that during CE, Vangl cell-autonomously recruits Dvl to the plasma membrane but simultaneously keeps Dvl inactive. In this study, we show that non-canonical Wnt induces Dvl to transition from Vangl to Fz. PK inhibits the transition, and functionally synergize with Vangl to suppress Dvl during CE. Conversely, Ror is required for the transition, and functionally antagonizes Vangl. Biochemically, Vangl interacts directly with both Ror and Dvl. Ror and Dvl do not bind directly, but can be cofractionated with Vangl. We propose that Pk assists Vangl to function as an unconventional adaptor that brings Dvl and Ror into a complex to serves two functions: 1) simultaneously preventing both Dvl and Ror from ectopically activating non-canonical Wnt signaling; and 2) relaying Dvl to Fz for signaling activation upon non-canonical Wnt induced dimerization of Fz and Ror.

Search for a Grotthuss mechanism through the observation of proton transfer

The transport of protons is critical in a variety of bio- and electro-chemical processes and technologies. The Grotthuss mechanism is considered to be the most efficient proton transport mechanism, generally implying a transfer of protons between 'chains' of host molecules via elementary reactions within the hydrogen bonds. Although Grotthuss proposed this concept more than 200 years ago, only indirect experimental evidence of the mechanism has been observed. Here we report the first experimental observation of proton transfer between the molecules in pure and 85% aqueous phosphoric acid. Employing dielectric spectroscopy, quasielastic neutron, and light scattering, and ab initio molecular dynamic simulations we determined that protons move by surprisingly short jumps of only ~0.5-0.7 Å, much smaller than the typical ion jump length in ionic liquids. Our analysis confirms the existence of correlations in these proton jumps. However, these correlations actually reduce the conductivity, in contrast to a desirable enhancement, as is usually assumed by a Grotthuss mechanism. Furthermore, our analysis suggests that the expected Grotthuss-like enhancement of conductivity cannot be realized in bulk liquids where ionic correlations always decrease conductivity.

CHANGE OF SURGICALLY INDUCED CORNEAL ASTIGMATISM AND POSITION OF ARTIFICIAL INTRAOCULAR LENS OVER TIME

AIMS

To analyze changes in surgically induced corneal astigmatism and articial intraocular lens (IOL) stability over time following cataract surgery. To compare the interchangeability of measurements between an automatic keratorefractometer (AKRM) and a biometer.

MATERIAL AND METHODS

In this prospective observational study, the above-mentioned parameters were collected from 25 eyes (25 subjects) on the first day, first week, first and third month after uncomplicated cataract surgery. We used IOL-induced astigmatism (difference between refractometry and keratometry) as an indirect indicator of IOL stability change. We used the Blant-Altman method to analyze consistency between devices.

RESULTS

At the above time points, surgically induced astigmatism (SIA) decreased as follows: 0.65 D; 0.62 D; 0.60 D and 0.41 D (in the first day, week, month and third month respectively). Astigmatism induced by changes of the position of the IOL varied as follows: 0.88 D; 0.59 D; 0.44 D and 0.49 D. Changes in both parameters were statistically significant (p0.05).

CONCLUSION

Both surgically induced astigmatism and astigmatism induced by IOL decreased over time, in which both changes were statistically significant. The decrease in SIA was most pronounced between the first and third month after surgery. For IOL-induced astigmatism, the greatest decrease was within the first month after surgery. The differences in measurement between the biometer and AKRM were statistically insignificant, but the clinical interchangeability between the given methods is questionable, especially with regard to measurement of the astigmatism angle.

Use of Corneal Topography in Pediatric Ophthalmology

AIM

To introduce the topic of pediatric keratoconus, highlighting the importance of routine corneal topography and tomography in children and adolescents from predisposed groups. To attempt to ensure the early detection of keratoconus and its subclinical form, enabling early treatment, which brings better expected postoperative results.  Material and methods: Using the corneal tomograph Pentacam AXL we examined children and adolescents with astigmatism equal or greater than  2 diopters (in at least one eye) and patients with at least one risk factor such as eye rubbing in the case of allergic pathologies, positive family history of keratoconus or certain forms of retinal dystrophy. In total, we included 231 eyes (116 patients), of which 54 were girls and 62 were boys.

RESULTS

The Belin-Ambrósio deviation index parameter was evaluated, in which we classified a total of 41 eyes as subclinical keratoconus and 12 eyes as clinical keratoconus. Next, the corneal maps were evaluated individually, in which we included a total of 15 eyes as subclinical keratoconus and 6 eyes as clinical keratoconus. In our group, compared to the control group, subclinical and clinical keratoconus occurred most often in the group of patients with astigmatism and in the group of so-called "eye rubbers". After individual evaluation, keratoconus occurred more frequently in boys than in girls in our cohort.

CONCLUSION

Most patients with keratoconus are diagnosed when there is a deterioration of visual acuity and changes on the anterior surface of  the cornea. Corneal topography and tomography allows us to monitor the initial changes on the posterior surface of the cornea, and helps us to detect the subclinical form of keratoconus and the possibility of its early treatment. Therefore, it is important to determine which groups are at risk and groups in which corneal topography and tomography should be performed routinely.

Exploration of phase diagram, structural and dynamic behavior of [HMG][FSI] mixtures with NaFSI across an extended composition range

Hexamethylguanidinium bis(fluorosulfonyl)imide ([HMG][FSI]) has recently been shown to be a promising solid state organic ionic plastic crystal with potential application in advanced alkali metal batteries. This study provides a detailed exploration of the structural and dynamic behavior of [HMG][FSI] mixtures with the sodium salt NaFSI across the whole composition range from 0 to 100 mol%. All mixtures are solids at room temperature. A combination of differential scanning calorimetry (DSC), synchrotron X-ray diffraction (SXRD) and multinuclear solid state NMR spectroscopy is employed to identify a partial phase diagram. The 25 mol% NaFSI/75 mol% [HMG][FSI] composition presents as the eutectic composition with the eutectic transition temperature at 44 °C. Both DSC and SXRD strongly support the formation of a new compound near 50 mol% NaFSI. Interestingly, the 53 mol% NaFSI [HMG][FSI] composition was consistently found to display features of a pure compound whereas the 50 mol% materials always showed a second phase. Many of the compositions examined showed unusual metastable behaviour. Moreover, the ion dynamics as determined by NMR, indicate that the Na⁺ and FSI^- anions are signifcantly more mobile than the HMG cation in the liquid state (including the metastable state) for these materials.

Controlling the Ion Transport Number in Solvent-in-Salt Solutions

Solvent-in-salt (SIS) systems present promising materials for the next generation of energy storage applications. The ion dynamics is significantly different in these systems from that of ionic liquids and diluted salt solutions. In this study, we analyze the ion dynamics of two salts, Li-TFSI and Li-FSI, in highly concentrated aqueous and acetonitrile solutions. We performed high-frequency dielectric measurements covering the range of up to 50 GHz and molecular dynamics simulations. The analysis of the conductivity spectra provides the characteristic crossover time between individual charge rearrangements and the normal charge diffusion regime resulting in DC conductivity. Analysis revealed that the onset of normal charge diffusion occurs at the scale of ∼1.5-3.5 Å, comparable to the average distance between the ions. Based on the idea of momentum conservation, distinct ion correlations were estimated experimentally and computationally. The analysis revealed that cation-anion correlations can be suppressed by changing the solvent concentration in SIS systems, leading to an increase of the light ion (Li⁺ in our case) transport number. This discovery suggests a way for improving the light cation transport number in SIS systems by tuning the solvent concentration.

AB0614 Late-onset neutropenia after rituximab treatment in patients with ANCA-associated systemic vasculitis: a retrospective analysis of a register-based patient cohort

Background

Anti-B-cell therapy with rituximab (RTX) plays an important role in the induction and maintenance therapy of ANCA- associated vasculitis (AAV). Late-onset neutropenia (LON) has been reported following RTX therapy.

Objectives

Based on a retrospective analysis of the register of AAV patients (pts) treated with RTX, to study the incidence and outcomes of LON.

Methods

140 AAV pts (median age 52 (20-83) years, 57% women) were treated with RTX between 2009 to 2021: 63 with granulomatosis with polyangiitis (GPA), 45 microscopic polyangiitis (MPA), 24 eosinophilic granulomatosis with polyangiitis (EGPA), and 8 unclassified AAV. The median total dose of RTX was 3.5 (0.5-45) g. As a rule, single 500-mg infusions were used with an interval of 4-6 months for retreatment courses. The duration of follow-up exceeded 6 months after the first dose of RTX. Regular pts monitoring every 3 months included estimation absolute neutrophil count (ANC). LON was defined as unexplained neutropenia occurring 3 weeks after the last RTX infusion.

Results

LON I-IV grade was noted in 16 (11.4%) AAV pts: 6 GPA, 4 MPA, 4 EGPA, and 2 unclassified AAV. In 7 out of 16 cases (43.7%) LON developed after the first course of RTX. Neutropenia grade I was observed in 3 pts (ANC 1.68-2.0x109/l, 2-15.5 months after the last RTX infusion), grade II - in 4 patients (1.1-1.5x109/l, 3-9 months after RTX). Neutropenia grade I-II resolved independently, without adverse reactions. LON grade IV was noted in 9 pts (0.06-0.3x109/l, 1.1-11 months after RTX), 3 of them received leukopoiesis-stimulating drugs with normalization of ANC. In one EGPA pt febrile LON grade IV developed twice (in 2017, 11 months after RTX; in 2019, 4 months after RTX and complicated by uterine bleeding). Fatal outcome occurred in 5 out of 16 cases (31.2%): 1 MPA, 3 GPA, and 1 EGPA. In 3 fatal cases LON was complicated by pneumonia (in 2 with septic shock), in one with acute myocardial infarction and another one with progression of chronic renal failure. According to our registry, the total mortality among 140 AAV pts receiving RTX was 11.4%, while 5 of 16 fatal cases (31.2%) had LON grade IV. Three of the 5 death were noted in 2013-2014, which attributed to the use of cyclophosphamide >2 gm before RTX, as well as insufficient awareness of the risk of LON, which contributed to the delay in control of a full blood count, untimely diagnosis of LON and late treatment. At the beginning, the original drug Mabthera was used, while after 2014 biosimilar Acellbia was mainly used.

The disadvantages of this study: the lack of information about the ANC in 4 cases with COVID-19 and fatal outcome.

Conclusion

LON after RTX therapy can develop in 11.4% of AAV pts, which exceeds the data for rheumatoid arthritis (1,3-3%) [1,2]. Our register data are lower than the rate of LON in AAV, presented by D. Tesfa et al. (23%) [1], which could be affected by the use of low-dose RTX for retreatment courses. LON accounts for a significant part in the structure of deaths of AAV pts (31.2%). It needs to careful monitoring of ANC in pts receiving RTX and awareness of both pts and physicians about the risk of LON.

References

[1]Tesfa D, Ajeganova S, Hägglund H, et al. Late-onset neutropenia following rituximab therapy in rheumatic diseases: association with B lymphocyte depletion and infections. Arthritis Rheum. 2011;63(8):2209-14.

[2]Salmon J.H., Cacoub P., Combe B., et al. Late-onset neutropenia after treatment with rituximab for rheumatoid arthritis and other autoimmune diseases: data from the Autoimmunity and Rituximab registry. RMD Open.2015; 1.

Disclosure of Interests

None declared

SARS-COV-2 PANDEMIC FROM THE OPHTHALMOLOGIST`S PERSPECTIVE. A REVIEW

In December 2019, a novel coronavirus (CoV) epidemic, caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) emerged from China. Coronaviruses belong to enveloped ssRNA viruses and are classified into four genera: Alpha coronavirus, Beta coronavirus, Gamma coronavirus and Delta coronavirus. It is assumed that SARS-CoV-2 is spread primarily during a personal contact via bigger respiratory droplets. These droplets with viruses can be directly inhaled by other people or can lend on the surfaces with the possibility of further spreading. The ocular surface has been suggested as one of possible infection entries. Human eye has its own renin-angiotensin system with present ACE2 receptors, which bind the virus through spike protein. The most common symptoms of the SARS-CoV-2 infection are fever, cough and dyspnoea. Several clinical entities, such as conjunctivitis, anterior uveitis, retinitis, and optic neuritis have been associated with this infection. The most common ophthalmologic symptom associated with COVID-19 disease is conjunctivitis. Some studies indicate that eye symptoms are commonly present in patients with severe COVID-19 pneumonia and that it is possible to detect viral RNA from the conjunctival sac of these patients. In ophthalmologic praxis, we manage not only the therapy of the eye structures` inflammation in relation with this infection, but also the overall management of the visits and the supervision of the patients who are at risk and positive for coronavirus. Ophthalmologists could potentially have a higher risk of SARS-CoV-2 infection due to personal communication with the patients, frequent exposure to tears and eye secrets and the use of devices. We would like to provide an ophthalmologist`s perspective on this topic.

ENDOTHELIAL CELL LOSS AFTER PARS PLANA VITRECTOMY

AIMS

To analyse the changes in endothelial cell density (ECD) after pars plana vitrectomy (PPV) and to identify the factors implicated.

PATIENTS AND METHODS

This was a prospective, consecutive, and non-randomised, case-control study. All 23-gauge vitrectomies were performed by a single surgeon at a tertiary centre. ECD was measured at baseline before surgery and on postoperative Days 30, 90, and 180. The fellow eye was used as the control eye. The primary outcome was a change in ECD after PPV.

RESULTS

Seventeen patients were included in this study. The mean age of the patients was 65 years. The mean ECD count at baseline was 2340 cells/mm2. The median ECD loss in the vitrectomised eye was 3.6 %, 4.0 %, and 4.7 % at Days 30, 90, and 180, respectively, compared to +1.94 %, +0.75 %, +1.01 %, respectively, in the control eye. The relative risk of ECD loss after PPV was 2.48 (C.I. 1.05-5.85, p = 0.0247). The pseudophakic eyes lost more ECD than the phakic eyes, but this was not statistically significant. There were no significant differences in diagnosis, age, surgical time, or tamponade used after surgery.

CONCLUSIONS

Routine pars plana vitrectomy had an impact on the corneal endothelial cells until Day 180 post-op. The phakic status was slightly protective against ECD loss after PPV, although it was not statistically significant. The pathophysiology of corneal cell damage after routine PPV remains unclear. Further studies are required to confirm these findings.

Rivaroxaban for the prevention of venous thromboembolism after radiofrequency ablation of saphenous veins concomitant with miniphlebectomy, sclerotherapy, or no treatment of varicose tributaries

OBJECTIVE

To assess the efficacy and safety of once-daily 10 mg rivaroxaban for venous thromboembolism prophylaxis after ClosureFast radiofrequency ablation (RFA) of saphenous veins.

METHOD

The medical records of patients, who had a Caprini score of ≥3, underwent RFA, received prophylactic rivaroxaban for five days, and completed follow up at one month were reviewed for efficacy (a combination of endovenous heat-induced thrombosis [EHIT] grade of 2-4, any symptomatic or asymptomatic deep vein thrombosis [DVT], and symptomatic pulmonary embolism [PE]) and safety (a combination of major and clinically relevant non-major [CRNM] bleeding) outcomes.

RESULTS

The results of RFA for 248 great saphenous and 24 small saphenous veins with the concomitant miniphlebectomy (63.8%) and sclerotherapy (16.5%) were analyzed. The primary efficacy outcome occurred in 5 of 218 (2.3%; 95%CI, 1.0-5.3%) patients: three EHITs and two symptomatic DVTs. The CRNM bleeding was reported in two patients (0.9%; 95% CI, 0.2-3.3%). No difference was observed in comparison with 79 similar patients who received 40 mg of subcutaneous enoxaparin during the same time period.

CONCLUSION

Once-daily 10 mg rivaroxaban is suitable for VTE prophylaxis after RFA of saphenous veins.

Modulation of Cation Diffusion by Reversible Supramolecular Assemblies in Ionic Liquid-Based Nanocomposites

Ionic liquid (IL) properties, such as high ionic conductivity under ambient conditions combined with nontoxicity and nonflammability, make them important materials for future technologies. Despite high ion conductivity desired for battery applications, cation transport numbers in ILs are not sufficient enough to attain high power density batteries. Thus, developing novel approaches directed toward improvement of cation transport properties is required for the application of ILs in energy-storing devices. In this effort, we used various experimental techniques to demonstrate that the strategy of mixing ILs with ultrasmall (1.8 nm) nanoparticles (NPs) resulted in melt-processable composites with improved transport numbers for cations at room temperature. This significant enhancement in the transport number was attributed to the specific chemistry of NPs exhibiting a weaker cation and stronger anion coordination at ambient temperature. At high temperature, significantly weakened NP-anion associations promoted a liquid-like behavior of composites, highlighting the melt-processability of these composites. These results show that designing a reversible dynamic noncovalent NP-anion association controlled by the temperature may constitute an effective strategy to control ion diffusion. Our studies provide fundamental insights into mechanisms driving the charge transport and offer practical guidance for the design of melt-processable composites with an improved cation transport number under ambient conditions.

PUPILLOTONIA AND ADIE SYNDROME

The aim of the work is to approach the examination of the pupil with a focus on anisocoria, its characteristics and approach to the diagnosis of pupillotonia and Adie&#39;s syndrome and its clinical evaluation. Pupil function is important not only in neurophthalmological examination but also in general ophthalmological examination. First of all, we need to know how the reflex arc works in order to be able to exclude or confirm whether the parasympathetic or sympathetic is affected. It is also necessary to know the exact characteristics of the pupil, such as size, shape, placement, function and reaction to light and at close range. Only on this basis can we distinguish pathological features. We do not often encounter this diagnosis, but it is necessary to keep it in mind, especially in the field of neurophthalmology but also in general ophthalmology. We also present three cases of pupilotonia and Adie&#39;s syndrome, which we diagnosed at the Department of Ophthalmology, Faculty of Medicine, Comenius University, after the patient himself came by emergency admission or was sent directly to ophthalmology clinic. In the discussion, we present various other diagnoses, where the reflex arc may not be affected, but the pathological pupil is caused by intraocular tumors, general systemic diseases and, last but not least, local therapy or alkaloids.

P5545Predictors of 10-year mortality and re-intervention in patients with multivessel coronary disease, reduced systolic left ventricular function, after complete revascularization by PCI or CABG

Introduction

In patients with multivessel coronary disease, the decision on revascularization should be made through a heart team. Whether there is an optimal method and what are the predictors of mortality and repeated interventions is the subject of numerous studies.

Purpose

To determine what are the predictors of 10-year mortality and repeated interventions in patients with multivessel coronary disease and reduced systolic left ventricular function in which complete revascularization is done through percutaneous coronary intervention (PCI) and surgical aortocoronary bypass (CABG).

Methods

The survey included 178 patients who underwent elective revascularization of multivessel coronary disease in one center during 2008 through PCI or bypass, according to the heart team's decision. All subjects had a reduced left ventricular systolic function, ejection fraction less than 50%. The study excluded patients with acute coronary syndrome. The basic demographic and clinical characteristics of the subjects and risk factors were analyzed.

Results

Ten-year mortality was 31.4%, without a significant difference between the examined groups (in the PCI group 25 patients (30.5%) in the bypass group 30 (32.3%), p>0.05). In subjects with letal outcome during 10-year follow-up, lower hemoglobin levels in discharge, enlarged cardiac cavities, increased internal diameter of left ventricle in systole (LVIDs) and enlarged left atrium, lower systolic left ventricular function, higher EUROscore and higher NYHA class in discharge. The enlarged left ventricular diameter in systole (OR 2.28 (1.27–4.11), p=0.006) and the NYHA class (OR 2.49 (1.22–5.08), p=0.012) are independent predictors ten-year mortality. In the group of patients undergoing surgical revascularization, independent predictors of 10-year mortality are higher levels of uric acid (OR 1,006 (1,000–1,011), P=0,047) and lower serum hemoglobin at discharge (OR 0,959 (0,919–0,999), P=0.046), while in PCI group LVIDs (OR 2.89 (1.351–6.196), p=0.006). During the 10-year follow-up, repeated PCI was performed in 12 (14.5%) patients in the PCI group and in 3 (3.2%) patients in the CABG group, p=0.012. No surgical revascularization was performed during follow up. Diabetes mellitus is an independent predictor of reintervention in the PCI group (OR 4.12 (1.153–14.703), p=0.029).

Conclusion

Mortality predictors during ten years of follow-up in subjects following a revascularization of multivessel coronary disease, and with reduced left ventricular systolic function, are increased systolic left ventricular diameter and higher NYHA class in discharge. Reintervention is more commonly performed after PCI and the presence of diabetes mellitus is an independent predictor.

Impact of velocity gradient in Poiseuille flow on the statistics of coherent radiation scattered by flowing Brownian particles in optical coherence tomography

A closed-form expression is obtained for the temporal correlation function of the scattered radiation detected in optical coherence tomography (OCT), taking into account the flow velocity gradient across the OCT detection volume in the suspension of flowing Brownian particles. The analytical approach we use includes both the laser beam and wavefront curvature radii changing over the depth. Also, we compare our results with a previously obtained theoretical model, partially an empirical approach. Our findings suggest the importance of the flow velocity gradient for accurate measurements of flow velocity vector, particle diffusivity, shear-induced diffusion, and potentially other OCT applications.

EFFECT OF MULTIPLE VARIABLES ON THE REFRACTIVE ERROR AFTER CATARACT SURGERY

PURPOSE

To analyze refractive results after cataract surgery in relation to used type of monofocal intraocular lens, calculation formula, to age, gender and laterality.

SETTINGS

Department of Ophthalmology, Comenius University and University hospital in Bratislava, Slovakia Methods: We analyzed 173 eyes (118 patients) after uneventful cataract surgery. We calculated prediction error (PE) and mean absolute error (MAE) of postoperative refraction.

RESULTS AND CONCLUSION

We found no statistically significant differences in PE and MAE in relation to types of used IOL, calculation formulas, gender, age or laterality. Key words: Optical biometry, monofocal IOL, IOL calculation, refractive error.

Structural correlations tailor conductive properties in polymerized ionic liquids

In this paper, it was demonstrated that the mobile ion (anion) size and pendant group chemistry affect the packing of the polymer chains and influence conductivity in imidazolium based PolyILs.

Sleep and disruptive mood dysregulation disorder: A pilot actigraphy study

OBJECTIVE

To explore the clinical characteristics and motor activity profile during sleep periods of children and adolescents presenting with disruptive mood dysregulation disorder (DMDD).

METHOD

Twenty-one youths (mean age±standard deviation, 11.7±3 years) wore a wrist actigraph for 9 consecutive days (including both school days and non-school days), to measure sleep parameters: sleep latency, sleep efficiency and the number and duration of periods of wakefulness after sleep onset (WASO). We divided the night-time actigraphy recording sessions into three sections and compared the first and last thirds of the night.

RESULTS

All the study participants had a psychiatric comorbidity (primarily attention deficit hyperactivity disorder, depressive disorder or anxiety disorder). On non-school days, bedrest onset and activity onset were shifted later by about 1h. There was no significant difference between school days and non-school days with regard to the total sleep time. Sleep efficiency was significantly greater on non-school days. Sleep was fragmented on both school days and non-school days. The mean number of episodes of WASO was 24.9 for school days and 30.9 for non-school days. Relative to the first third of the night, we observed a significantly greater number of episodes of WASO during the last third of the night, a period associated with a larger proportion of rapid eye movement (REM) sleep.

DISCUSSION

Sleep appeared to be fragmented in the study population of youths with DMDD. The greater frequency of WASO in the last third of the night points to a possible impairment of the motor inhibition normally associated with REM sleep.

K-distribution three-dimensional mapping of biological tissues in optical coherence tomography

Probability density function (PDF) analysis with K-distribution model of optical coherence tomography (OCT) intensity signals has previously yielded a good representation of the average number of scatterers in a coherence volume for microspheres-in-water systems, and has shown initial promise for biological tissue characterization. In this work, we extend these previous findings, based on single point M-mode or two-dimenstional slice analysis, to full three-dimensional (3D) imaging maps of the shape parameter α of the K-distribution PDF. After selecting a suitably sized 3D evaluation window, and verifying methodology in phantoms, the resultant parametric α images obtained in different animal tissues (rat liver and brain) show new contrasting ability not seen in conventional OCT intensity images.

The low-temperature dynamic crossover in the dielectric relaxation of ice Ih

Based on the idea of defect migration as the principal mechanism in the dielectric relaxation of ice I_h, the concept of low-temperature dynamic crossover was proposed. It is known that at high temperatures, the diffusion of Bjerrum and ionic defects is high and their movement may be considered to be independent. Simple switching between these two mechanisms leads to a dynamic crossover at ∼235 K. By introducing coupling between the Bjerrum and ionic defects, it is possible to describe the smooth bend in the relaxation time at low temperatures in ice I_h. However, because the mobility of Bjerrum orientation defects slows down at low temperatures, they may create blockages for proton hopping. The trapping of ionic defects by L-D defects for a long period of time leads to an increase in the relaxation time and causes a low-temperature crossover. This model was validated by experimental dielectric measurements using various temperature protocols.

Combination of Intravitreal Corticosteroid with Anti-vegf in Macular Edema Secondary to Retinal Vein Occlusion

PURPOSE

functional and anatomical results after combination of intravitreal dexamethasone implant with anti-VEGF bevacizumab in macular edema secondary to retinal vein occlusion.

METHODS

Retrospective analysis of 50 patients, average age 72 years, 15 men and 35 women. Inclusion criteria for treatment were retinal vein occlusion, best corrected visual acuity (BCVA) more than 20/200 and macular edema more than 250 μm. Algorithm of treatment was dexamethason, anti-VEGF (bevacizumab), dexamethason. Application of anti-VEGF bevacizumab was in interval between two applications of dexamethasone, for the first time in every patient. If there were nonperfusion areas on fluoresceine angiography (FA), or ischemia on slit lamp, repeatedly. Patients observed for 12 months at least. This cohort included patients with branch retinal vein occlusion together with central retinal vein occlusion. This is an evaluation of nonperfusion areas based on FA, BCVA, macular edema on optical coherence tomography (OCT) and number of reapplication of anti-VEGF bevacizumab. Observed adverse effects are elevation of intraocular pressure and number of patients who underwent cataract surgery.

RESULTS

The gain of 8 letters in 1st month after 1st application of dexamethasone, central retinal thickness (CRT) reduced from 512 μm to 318 μm in average. 33 patients get 1, 3 patients get 2 and 14 patients 3 injections of bevacizumab. On the day of 2nd application of dexamethasone, in 7th month in average, the CRT increased on 465 μm, and 1th month after, the gain from the baseline was 10 letters and CRT reduced on 380 μm. All the patients were phackic at the baseline, 18 (36 %) patients underwent cataract surgery with intraocular lens implantation. Transient elevation of intraocular pressure in 15 (30 %) eyes, treated by local therapy.

CONCLUSION

Combination of intravitreal dexamethasone implant with anti-VEGF bevacizumab is functionally and anatomically effective. Key words: retinal vein occlusion, macular edema, dexamethasone, bevacizumab.

p21 does, but p53 does not predict pathological response to preoperative chemoradiotherapy in locally advanced rectal cancer

PURPOSE

Preoperative chemoradiotherapy (CRT) is the standard treatment option in locally advanced rectal cancer. The tumor response is assessed through tumor and nodal downstaging and the tumor regression grade. Currently, there is no method to predict a tumor response to CRT. We aimed to evaluate whether p21 and p53 expressions could be a reliable predictors of pathological response to CRT.

METHODS

Fifty patients with locally advanced rectal cancer were treated with preoperative radiotherapy combined with mitomycin C and capecitabine. p21 and p53 immumohistochemical staining was performed on pretreatment biopsies and the results were compared with tumor regression according to grading systems by Dworak (TRG grades) and by Wheeler (RCRG grades).

RESULTS

Testing RCRG grades in relation to p21 expression showed statistically significant difference (p=0.021). RCRG 3 (poor response) was more frequent in the group of patients with low p21. According to Dworak, grade 4 (complete regression) was more frequent in the group of patients with positive p21 expression (p=0.032). Significant difference in p21 expression in grade 4 group compared with all other grade groups was also found (p=0.007). Patients with immune expression of p21 had significantly higher percentage of complete regression in comparison to the patients with low expression of p21. We haven't found any correlation between p53 expression and histopathological (HP) as well as regression grades.

CONCLUSION

According to both grading systems, our results suggest that p53 expression does not, but p21 expression does predict pathological response to preoperative CRT.

Confined water dynamics in a hydrated photosynthetic pigment-protein complex

Water is of fundamental importance for life. It plays a critical role in all biological systems. In phycocyanin, a pigment-protein complex, the hydration level influences its absorption spectrum. However, there is currently a gap in the understanding of how protein interfaces affect water's structure and properties. This work presents combined dielectric and calorimetric measurements of hydrated phycocyanin with different levels of hydration in a broad temperature interval. Based on the dielectric and calorimetric tests, it was shown that two types of water exist in the phycocyanin hydration shell. One is confined water localized inside the phycocyanin ring and the second is the water that is embedded in the protein structure and participates in the protein solvation. The water confined in the phycocyanin ring melts at the temperature 195 ± 3 K and plays a role in the solvation at higher temperatures. Moreover, the dynamics of all types of water was found to be effected by the presence of the ionic buffer.

Accurate viscosity measurements of flowing aqueous glucose solutions with suspended scatterers using a dynamic light scattering approach with optical coherence tomography

The viscosity of turbid colloidal glucose solutions has been accurately determined from spectral domain optical coherence tomography (OCT) M-mode measurements and our recently developed OCT dynamic light scattering model. Results for various glucose concentrations, flow speeds, and flow angles are reported. The relative "combined standard uncertainty" uc(η) on the viscosity measurements was ±1% for the no-flow case and ±5% for the flow cases, a significant improvement in measurement robustness over previously published reports. The available literature data for the viscosity of pure water and our measurements differ by 1% (stagnant case) and 1.5% (flow cases), demonstrating good accuracy; similar agreement is seen across the measured glucose concentration range when compared to interpolated literature values. The developed technique may contribute toward eventual noninvasive glucose measurements in medicine.

Thermal dissociation of ions limits the degree of the gas-phase H/D exchange at the atmospheric pressure

We present the application of the extended desolvating capillaries for increasing the degree of the gas-phase hydrogen/deuterium exchange reaction at atmospheric pressure. The use of the extended capillaries results in the increase of the time that ions spend in the high pressure region, what leads to the significant improvement of the efficiency of the reaction. For the small protein ubiquitin, it was observed that for the same temperature, the number of exchanges increases with the decrease of the charge state so that the lowest charge state can exchange twice the number of hydrogen than the highest one. With the increase of the temperature, the difference decreases, and eventually, the number of exchanges equalizes for all charge states. The value of this temperature and the corresponding number of exchanges depend on the geometric parameters of the capillary. Further increase of the temperature leads to the thermal dissociation of the protein ion. The observed b/y fragments are identical to those produced by collision-induced dissociation performed in the ion trap. Copyright © 2017 John Wiley & Sons, Ltd.

Statistical properties of dynamic speckles from flowing Brownian scatterers in the vicinity of the image plane in optical coherence tomography

A closed-form analytical expression is obtained for the spatio-temporal correlation function of the scattered radiation detected in fiber-based optical coherence tomography (OCT), assuming a clean optical system arrangement in the OCT sample arm. It is shown that the transverse flow component causes purely translational speckle motion with the predicted speckle velocity 2x higher than the velocity of the flowing particles as would be observed in the image plane under incoherent illumination. It is also shown that both speckle velocity and speckle radius do not depend on the position of the scattering volume relative to the focal plane, hence the derived correlation function is independent of the position of the scattering volume relative to the focal plane. Although the analytical results are obtained for a clean optical system arrangement, they can be used with high accuracy in most practical implementations of fiber based OCT. Validation experiments in control scattering phantoms with varying liquid viscosities show excellent agreement with the developed theoretical model, under both no-flow and flow conditions. Accurate viscosity determinations enabled by this methodology may have applications to non-invasive glucose measurements in medicine.

Prevalence of refractive errors in the Slovak population calculated using the Gullstrand schematic eye model

PURPOSE

A substantial part of the population suffers from some kind of refractive errors. It is envisaged that their prevalence may change with the development of society. The aim of this study is to determine the prevalence of refractive errors using calculations based on the Gullstrand schematic eye model.

METHODS

We used the Gullstrand schematic eye model to calculate refraction retrospectively. Refraction was presented as the need for glasses correction at a vertex distance of 12 mm. The necessary data was obtained using the optical biometer Lenstar LS900. Data which could not be obtained due to the limitations of the device was substituted by theoretical data from the Gullstrand schematic eye model. Only analyses from the right eyes were presented. The data was interpreted using descriptive statistics, Pearson correlation and t-test. The statistical tests were conducted at a level of significance of 5%.

RESULTS

Our sample included 1663 patients (665 male, 998 female) within the age range of 19 to 96 years. Average age was 70.8 ± 9.53 years. Average refraction of the eye was 2.73 ± 2.13D (males 2.49 ± 2.34, females 2.90 ± 2.76). The mean absolute error from emmetropia was 3.01 ± 1.58 (males 2.83 ± 2.95, females 3.25 ± 3.35). 89.06% of the sample was hyperopic, 6.61% was myopic and 4.33% emmetropic. We did not find any correlation between refraction and age.

CONCLUSION

Females were more hyperopic than males. We did not find any statistically significant hypermetopic shift of refraction with age. According to our estimation, the calculations of refractive errors using the Gullstrand schematic eye model showed a significant hypermetropic shift of more than +2D. Our results could be used in future for comparing the prevalence of refractive errors using same methods we used.Key words: refractive errors, refraction, Gullstrand schematic eye model, population, emmetropia.

Analysis of scattering statistics and governing distribution functions in optical coherence tomography

The probability density function (PDF) of light scattering intensity can be used to characterize the scattering medium. We have recently shown that in optical coherence tomography (OCT), a PDF formalism can be sensitive to the number of scatterers in the probed scattering volume and can be represented by the K-distribution, a functional descriptor for non-Gaussian scattering statistics. Expanding on this initial finding, here we examine polystyrene microsphere phantoms with different sphere sizes and concentrations, and also human skin and fingernail in vivo. It is demonstrated that the K-distribution offers an accurate representation for the measured OCT PDFs. The behavior of the shape parameter of K-distribution that best fits the OCT scattering results is investigated in detail, and the applicability of this methodology for biological tissue characterization is demonstrated and discussed.

Probability density function formalism for optical coherence tomography signal analysis: a controlled phantom study

The distribution of backscattered intensities as described by the probability density function (PDF) of tissue-scattered light contains information that may be useful for tissue assessment and diagnosis, including characterization of its pathology. In this Letter, we examine the PDF description of the light scattering statistics in a well characterized tissue-like particulate medium using optical coherence tomography (OCT). It is shown that for low scatterer density, the governing statistics depart considerably from a Gaussian description and follow the K distribution for both OCT amplitude and intensity. The PDF formalism is shown to be independent of the scatterer flow conditions; this is expected from theory, and suggests robustness and motion independence of the OCT amplitude (and OCT intensity) PDF metrics in the context of potential biomedical applications.

Outpatient laparoscopic sleeve gastrectomy: first 100 cases

STUDY OBJECTIVE

The development of outpatient surgery was one of the major goals of public health policy in 2010. The purpose of this observational prospective study was to evaluate the feasibility of laparoscopic sleeve gastrectomy (SG) in an ambulatory setting.

DESIGN

Study design was a prospective prospective observational, nonrandomized study, registered (ClinicalTrials.gov identifier: NCT01513005), with institutional review board approval and written informed consent.

SETTING

Amiens University Medical Center.

PATIENTS

Patients undergoing SG who were preselected by inclusion ambulatory criteria.

INTERVENTIONS

All patients operated on for obesity by laparoscopic SG, from May 2011 through July 2013.

MEASUREMENTS

We collected outcomes data on 100 patients including incidence of postoperative nausea and vomiting, maximum and average pain scores, and the overall satisfaction rate.

MAIN RESULTS

Of the 100 obese patients, 93% were women. The mean age was 36 years (22-55 years). The mean preoperative body mass index was 42.4 kg/m(2). The mean operating time was 60 minutes (range, 30-95 minutes). The overall satisfaction rate was 93% (n = 93). When leaving the postoperative care unit, 94% of patients felt no or mild pain. Eighty-two percent had no postoperative postoperative nausea and vomiting, and 7 patients needed treatment using ondasetron.

CONCLUSIONS

Laparoscopic SG in an ambulatory setting is feasible with a dedicated anesthesiological approach and an expert surgical team. Appropriate patient selection is important for ensuring safety and quality of care within the outpatient program.

Abstract P2-09-18: Exploration of the diagnostic utility of next generation sequencing with TruSight cancer panel for BRCA negative hereditary breast and ovarian cancer patients

Background. Breast cancer is the most commonly diagnosed malignancy and the most frequent cause of death in women due to cancer. About 5% to 10% of breast cancers are thought to be hereditary. Pathogenic mutations in BRCA1/2 genes across Hereditary Breast and Ovarian Cancer (HBOC) patients estimates are at around 15-20%. Other less common genes have also been associated with an increased risk of developing breast cancer, such as mutations in the TP53, PTEN, RAD51C, CDH1, ATM, CHEK2 or PALB2 tumor suppression genes. NGS based sequencing panels allow fast and simultaneous screening of large number of high- and low-penetrance susceptibility genes in these patients.

Methods. In the current study we included a group of 31 Bulgarian female breast cancer patients, selected following the strict BCLC and NCCN criteria for hereditary cancer. All of them were prescreened by direct sequencing and MLPA analysis, and tested negative for pathogenic mutations in BRCA1 and BRCA2 genes. Next generation target resequencing using a panel of 94 cancer related genes (Illumina TruSight cancer panel) was performed to explore the hereditary component beyond BRCA1/2 genes in these patients. All detected mutations and variants of unknown clinical significance (VUSs) were confirmed by Sanger sequencing method.

Results. Pathogenic and likely pathogenic mutations were found in 14 out of 31 BRCA1/2 negative patients: 1 new frameshift mutation in ATM gene; 6 new likely pathogenic missense mutations in PTCH1, RAD51C, MET, MUTYH, ATM and CHEK2; 7 previously reported pathogenic missense variants in WRN, ERCC4, PALB2, PRF1, RET, SDHB and AIP genes. In addition 27 VUSs (one new splice donor variant in ALK gene and 26 missense variants) were found.

Conclusions. The use of next generation target resequencing with TruSight Cancer panel lead to identification of clinically relevant pathogenic variants in 45% of the investigated patients. This could be the preferred diagnostic method in HBOC patients, carefully selected according the strict BCLC and NCCN criteria.

Citation Format: Dacheva D, Dodova R, Mitkova A, Kamenarova K, Tzveova R, Popov I, Vlahova A, Taushanova – Hadjieva M, Valev S, Dikov T, Timcheva K, Christova S, Mitev V, Kaneva R. Exploration of the diagnostic utility of next generation sequencing with TruSight cancer panel for BRCA negative hereditary breast and ovarian cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-18.

The role of the confined water in the dynamic crossover of hydrated lysozyme powders

This work presents combined dielectric and calorimetric measurements of hydrated lysozyme powders with different levels of hydration in a broad temperature interval.

The mechanism of the dielectric relaxation in water

The water spectra from Raman and Dielectric spectroscopies are combined to present a cohesive description of water dynamics up to the THz region.

Reversal of neuromuscular blockade by sugammadex in laparoscopic bariatric surgery: In support of dose reduction

INTRODUCTION

Sugammadex is the first molecule able to antagonize steroidal muscle relaxants with few adverse effects. Doses are adjusted to body weight and the level of neuromuscular blockade. Sleeve gastrectomy is becoming a very popular form of bariatric surgery. It requires deep muscle relaxation followed by complete and rapid reversal to decrease postoperative and especially post-anaesthetic morbidity. Sugammadex is therefore particularly indicated in this setting. The objective of this study was to evaluate the deep neuromuscular blockade reversal time after administration of various doses of sugammadex (based on real weight or at lower doses). Secondary endpoints were the interval between the sugammadex injection and extubation and transfer from the operating room to the recovery room. We then investigated any complications observed in the recovery room.

MATERIALS AND METHODS

This pilot, prospective, observational, clinical practice evaluation study was conducted in the Amiens University Hospital. Neuromuscular blockade was induced by rocuronium. At the end of the operation, deep neuromuscular blockade was reversed by sugammadex at the dose of 4mg/kg.

RESULTS

Sixty-four patients were included: 31 patients received sugammadex at a dosage based on their real weight (RW) and 33 patients received a lower dose (based on ideal weight [IW]). For identical rocuronium doses calculated based on IBW, sugammadex doses were significantly lower in the IW group: 349 (± 65) mg versus 508 (± 75) mg (P<0.0001). Despite this dose reduction, neuromuscular blockade reversal took 115 (± 69) s in the IW group versus 87 (± 40) s in the RW group, but with no significant difference between the two groups (P=0.08). The intervals between injection of sugammadex and extubation (P=0.07) and transfer from the operating room to the recovery room (P=0.68) were also non-significantly longer in the IW group. The mean dose of sugammadex used by anaesthetists in the IW group was 4mg/kg of ideal weight increased by 35% to 50% (n=20; 351±34mg). No sugammadex adverse effects and no residual neuromuscular blockades were observed. Postoperative nausea and vomiting (PONV) was observed in 19.4% of patients in the real weight group versus 27.3% in the ideal weight group (P=NS).

CONCLUSION

Reversal of deep neuromuscular blockades by sugammadex in obese subjects can be performed at doses of 4mg/kg of ideal weight plus 35-50% with no clinical consequences and no accentuation of adverse effects.