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.