bluuebunny/crossref_metadata_2025 huggingface dataset:
Specific recognition of ribavirin in animal‐derived foods by high performance liquid chromatography combined with magnetic solid‐phase extraction based on highly selective Zr‐Fe3O4
Authors: Qie Meili , Zheng Su , Xiaoyun Bai , Bo Zhang , Guozhen Fang , Shuo Wang
Published: June 2019

For the first time, a magnetic solid‐phase extraction with high‐performance liquid chromatography detection method using Zr functionalized Fe3O4 magnetic material to enrich ribavirin was successfully established. Zr components that modified in Fe3O4 nanoparticles via a simple one‐step hydrothermal method was selected in this work to specifically capture ribavirin by the strong chemical bonding between Zr components of Zr functionalized Fe3O4 magnetic material and cis‐hydroxyl of ribavirin, which was confirmed by pseudo‐second‐order kinetic model. And Fe3O4 components were selected in this work to achieve simple operation. Under the optimal experimental conditions, proposed magnetic solid‐phase extraction with high‐performance liquid chromatography detection method along with Zr functionalized Fe3O4 magnetic material offered a wide range linearity at 10–200 µg/L with correlation coefficient of 0.9978 with low detection limit of 2.68 µg/L for ribavirin. The relative standard deviations obtained from nine parallel extractions of 100 µg/L ribavirin were 4.41% and revealed good repeatability. This established method was successfully applied to detect real samples including chicken liver, egg, and shrimp with satisfactory recoveries of 74.13–92.9%.
Toughening Mechanism of Hydrophobic Association Hydrogels Reinforced by Latex Particles
Authors: Cheng Ya , Ren Xiuyan , Duan Lijie , Gao Guanghui
Published: June 2019

In this investigation, the copolymer poly(n‐butyl acrylate)‐b‐PEG‐b‐poly(n‐butyl acrylate) hydrogel is synthesized by atom transform radical polymerization and chosen as a simplified hydrophobic association hydrogel model. After adding the latex particles, hydrophobic poly(n‐butyl acrylate) segments can self‐assemble in an aqueous solution, forming a hydrogel (LP‐Gel) model with network structure. Structures of this model system are investigated by small angle X‐ray scattering. Dynamics are investigated through a combination of linear viscoelastic and creep measurements. It is found that introduction of the latex particles increases the crosslinking density and the association energy compared to the particles‐free system. This simple LP‐Gel model reveals the toughening mechanism of latex particle‐modified hydrophobic association hydrogels.
Universal Relationships in Branched Architecture Formed in Conventional and Living Emulsion Polymerization
Authors: Tobita Hidetaka
Published: June 2019

Emulsion polymerization proceeds in a unique locus of polymerization, having confined submicron space with a higher polymer concentration compared with the corresponding bulk polymerization. Assuming the ideal polymerization kinetics and a constant polymer/monomer ratio, the branched architecture formed with the coexistence of chain transfer reaction to polymer is investigated by using a Monte Carlo simulation method, both for the conventional and living free‐radical polymerization (FRP). The universal relationships, unchanged by the polymer transfer constant and the primary chain length distribution, are found for the mean‐square radius of gyration Rg2, and the maximum span length LMS. The g‐ratio of Rg2 of the branched molecule to that for a linear molecule, as well as the weight fraction of LMS chain in a polymer, as a function of the number nb of branch points per molecule does not change with the kinetic parameters, beyond the differences of conventional and living FRP. A single linear equation nicely covers the relationship between Rg2 and LMS for both the conventional and living FRP. The characteristics found in this article contain many new insights into the complex branched polymer formation that stimulate further research.
Terpolymerization of Triisopropylsilyl Acrylate, Methyl Methacrylate, and Butyl Acrylate: Reactivity Ratio Estimation
Authors: Yousefi Fereshteh K. , Jannesari Ali , Pazokifard Shahla , Saeb Mohammad Reza , Scott Alison J. , Penlidis Alexander
Published: June 2019

Ternary monomer reactivity ratios of triisopropylsilyl acrylate (SiA), methyl methacrylate (MMA), and n‐butyl acrylate (BA), as common monomers in self‐polishing coatings (SPCs) binders are obtained using experimental data collected from free radical bulk polymerization at 70 °C. Different terpolymerizations at low and medium‐high conversions are performed at optimized feed compositions. Estimations are made using the error‐in‐variables model (EVM) framework, applying the recast form of the Alfrey–Goldfinger (AG) model and a direct numerical integration (DNI) approach to the collected data. Estimations from individual low and medium‐high conversion data are compared to those found with the combined data (full conversion range data). The highest certainty in point estimates are obtained with analysis of the full conversion range data. Furthermore, the reactivity ratios determined from the combined data fall between those found with analysis of individual low and medium‐high conversion data, another corroboration of reliable data collection. Reactivity ratios determined from analysis of the combined data (rSiA/MMA = 0.4185, rMMA/SiA = 1.3754, rSiA/BA = 0.8739, rBA/SiA = 0.5736, rBA/MMA = 0.3692, rMMA/BA = 1.7919) are used in the recast AG model to predict cumulative terpolymer composition as a function of conversion. The experimental data and model prediction show satisfactory agreement.
On gamma estimation via matrix kriging
Authors: Yun Xin , Hong L. Jeff , Jiang Guangxin , Wang Shouyang
Published: June 2019

In financial engineering, sensitivities of derivative prices (also known as the Greeks) are important quantities in risk management, and stochastic gradient estimation methods are used to estimate them given the market parameters. In practice, the surface (function) of the Greeks with respect to the underlying parameters is much more desired, because it can be used in real‐time risk management. In this paper, we consider derivatives with multiple underlying assets, and propose three stochastic kriging‐based methods, the element‐by‐element, the importance mapping, and the Cholesky decomposition, to fit the surface of the gamma matrix that can fulfill the time constraint and the precision requirement in real‐time risk management. Numerical experiments are provided to illustrate the effectiveness of the proposed methods.
Removing constraints to sustainable food production: new ways to exploit secondary metabolism from companion planting and GM
Authors: Pickett John A , Midega Charles AO , Pittchar Jimmy , Khan Zeyaur R
Published: June 2019

The entire process of agricultural and horticultural food production is unsustainable as practiced by current highly intensive industrial systems. Energy consumption is particularly intensive for cultivation, and for fertilizer production and its incorporation into soil. Provision of nitrogen contributes a major source of the greenhouse gas, N2O. All losses due to pests, diseases and weeds are of food for which the carbon footprint has already been committed and so crop protection becomes an even greater concern. The rapidly increasing global need for food and the aggravation of associated problems by the effects of climate change create a need for new and sustainable crop protection. The overall requirement for sustainability is to remove seasonal inputs, and consequently all crop protection will need to be delivered via the seed or other planting material. Although genetic modification (GM) has transformed the prospects of sustainable crop protection, considerably more development is essential for the realisation of the full potential of GM and thereby consumer acceptability. Secondary plant metabolism offers wider and perhaps more robust new crop protection via GM and can be accomplished without associated yield loss because of the low level of photosynthate diverted for plant defence by secondary metabolism. Toxic mechanisms can continue to be targeted but exploiting non‐toxic regulatory and signalling mechanisms should be the ultimate objective. There are many problems facing these proposals, both technical and social, and these are discussed but it is certainly not possible to stay where we are in terms of sustainability. The evidence for success is mounting and the technical opportunities from secondary plant metabolism are discussed here. © 2019 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Trap‐Limited Vacancy Diffusion in Silicon at High Temperatures
Authors: Voronkov Vladimir V.
Published: June 2019

A high‐temperature vacancy diffusivity (DV) in silicon crystals is high and consistent with the extrapolated low‐temperature diffusivity by Watkins. On the other hand, the apparent vacancy diffusivity in silicon wafers is significantly smaller than DV. In particular, this has become more evident by recently reported vacancy‐related donor profiles in high‐resistivity wafers subjected to rapid thermal annealing (RTA). The reported donor depth profiles are complicated and strongly dependent on the RTA conditions. Yet, they are well reproduced, assuming that wafers (in contrast to the crystals) contain an appreciable amount of some impurity that acts as an efficient trap for vacancies even in a high‐temperature range of RTA. The true vacancy diffusivity and the equilibrium ratio of the vacancy and self‐interstitial concentrations are deduced from these data.
Light‐Induced Degradation in Annealed and Electron Irradiated Silicon
Authors: Lauer Kevin , Krischok Stefan , Klein Thomas , Bähr Mario , Lawerenz Alexander , Röder Ralf , Ortlepp Thomas , Gohs Uwe
Published: June 2019

The composition of the defect, which is responsible for the boron–oxygen‐related light‐induced degradation (BO‐LID) of the carrier lifetime in silicon, still remains an unresolved issue. It has been recently suggested that the BO‐LID is due to the ASi‐Sii‐defect. Within this idea, the creation and discreation are governed by the interstitial silicon concentration. Annealing and electron beam (EB) irradiation are applied to influence the interstitial silicon concentration. The BO‐LID is observed in the case of diffusion‐oxygenated FZ (DOFZ) boron‐doped silicon after annealing at 650 and 450 °C for 4 h, respectively. A nearly complete discreation of the BO‐LID defect is found for the long‐term high temperature (16 h at 1050 °C) anneal. This discreation process is explained by the diffusion of the interstitial silicon atoms to other sinks such as the wafer surfaces. The degradation of the carrier lifetime due to illumination after the EB irradiation is unambiguously related to the BO‐LID phenomenon.
Study of the State of Industrial P2O5‐Containing Slags Relevant to Steelmaking Processes Based on a New Thermodynamic Database Developed for CaO–FeOx–P2O5–SiO2–MnO–MgO–Al2O3 Slags − Part I: Ternary and Lower Order Systems
Authors: Khadhraoui Sabrine , Hack Klaus , Jantzen Tatjana , Odenthal Hans‐Jürgen
Published: June 2019

During oxygen refining of steel, the slag undergoes large variations in terms of its composition, temperature, and oxygen partial pressure. This paper presents a study of the state of CaO–FeOx–P2O5 and CaO–FeOx–SiO2 based slags under various process conditions by means of thermodynamic calculations using a newly developed thermodynamic database. The database is developed in the scope of the European project BOF DePhos (RFSR‐CT‐2014‐00005) for the purpose of investigating different thermodynamic aspects of phosphorous containing steelmaking slags in the composition, temperature, and oxygen partial pressure ranges relevant for the industrial process. The non‐ideal associate solution model is used for the description of the Gibbs energy of the liquid phase and the compound energy formalism (CEF) for the description of the Gibbs energy of the solid solution phases. By means of coupling the thermodynamic database to the Software FactSage™, the state of the quasi‐ternary oxide systems CaO–FeOx–P2O5 and CaO–FeOx–SiO2 systems relevant to low and high phosphorus refining processes, respectively, is investigated. The results of the calculations are compared with reported experimental data in the literature and indicate that the incorporation of the effect of oxygen partial pressure p(O2), and thus that of the oxidation state of FeOx, is crucial for a proper modeling and assessment of the state of industrial BOF slags. With an increase in p(O2), a considerable increase in lime saturation for both quasi‐ternary systems is observed and a shrinkage in the silicate saturation regions for the CaO–FeOx–SiO2 system occurs. The consequences of the findings for the industrial process are discussed. Mathematical descriptions of the dependency of lime saturation on temperature and oxidation state of FeOx in the ternary systems are provided.
Physical and CFD Modeling of the Effect of Top Layer Properties on the Formation of Open‐Eye in Gas‐Stirred Ladles With Single and Dual‐Plugs
Authors: Ramasetti Eshwar Kumar , Visuri Ville‐Valtteri , Sulasalmi Petri , Palovaara Tuomas , Gupta Avishek Kumar , Fabritius Timo
Published: June 2019

In secondary steelmaking, the optimal size and position of open‐eye is important for effective alloying practice. In the current work, the effect of the top layer thickness and density on the formation of open‐eye in a gas stirred ladle was investigated. A one‐fifth scale water model of 150‐ton ladle was established with single and dual plug configurations for the physical modeling measurements. Air, water and three different oils were used to simulate the argon, liquid steel and slag in the water model, respectively. A transient Computational Fluid Dynamics (CFD) model based on Eulerian Volume of Fluid (VOF) approach was developed for numerical modeling of the fluid flow behavior. The physical modeling results show that the relative open‐eye area decreases from 46.7 to 5.6% when top layer thickness was increased from 0.75 to 7.5 cm using a gas flow rate of 7.5 NL min−1. The effect of the number of plugs on the open‐eye area for the same range of top layer thickness mentioned above was also studied. The relative open‐eye area generated due to the gas injection through the dual plugs decreased from 49.9 to 5.8%. To study the effect of top layer properties, rapeseed oil, castor oil and paraffin oil were employed for studying the effect of density and dynamic viscosity on the open‐eye formation. The results revealed that a larger open‐eye is formed when the density is increased. Furthermore, it was found out that the density of the upper phase dominates the open‐eye formation while dynamic viscosity has only minor effect. The results obtained from numerical simulations and physical modeling were found to be in good agreement.
Resistant Starch‐Supplemented Udon Noodles Prevent Impaired Glucose Tolerance and Induce Intestinal Immunoglobulin‐A Secretion in Mice
Authors: Matsumoto Kenji , Shimada Hiroki , Morishima Hiroki , Akahori Reina , Kida Naotaka
Published: June 2019

Resistant starch (RS) has received considerable attention recently because of its potential benefits upon glucose/lipid metabolism and intestinal conditions. RS‐supplemented Udon noodles (RS‐Udon) are prepared and their functional properties are compared with those of Udon noodles without RS (C‐Udon) in C57BL/6J mice. Both Udon samples are used after lyophilization. Single administration (250 mg kg−1 body weight, p.o.) of RS‐Udon tends to increase blood glucose levels less than that elicited by C‐Udon at 30 min. In a 13‐week‐treatment study, mice are fed a normal diet or a high‐fat diet (HFD; 45 kcal% fat) supplemented with 30% C‐Udon (HFD‐C group) or RS‐Udon (HFD‐RS group). RS‐Udon intake prevents the impaired glucose tolerance caused by HFD significantly. Fecal levels of immunoglobulin‐A are increased significantly in the HFD group compared with that in the HFD‐C group, a tendency that is also observed in fecal mucin content. The HFD‐RS group shows cecal propionate content 1.8‐fold higher than that in the HFD‐C group, which may be secondary to the beneficial effects of propionate upon glucose metabolism. Beneficial effects upon lipid metabolism are not observed in the HFD‐RS group. These results suggest that RS‐Udon ingestion may have beneficial effects on glucose metabolism and intestinal immune conditions.
Temporary Right Portocaval Shunt During Piggyback Liver Transplantation
Authors: Addeo Pietro , Locicero Andrea , Faitot François , Bachellier Philippe
Published: June 2019

Background

During piggyback liver transplantation (LT), a temporary end‐to‐side portocaval anastomosis (PCA) facilitates native total hepatectomy while maintaining hemodynamic stability. Some argue that PCA, performed on the main portal trunk (PT), might shorten the main portal vein and could cause technical difficulties during LT. We describe a temporary PCA performed on the right portal vein (R‐PCA).

Methods

The technique entails complete dissection of the main portal trunk up its right and left branches. After having ligated the left portal vein, the right is anastomosed end‐to‐side to the anterior face of the inferior vena cava. Taken down of R‐PCA, before graft‐recipient portal vein anastomosis, is achieved by stapling or suturing.

Results

An R‐PCA has been performed in 14 over 15 planned procedures at our unit. In one case, because of intraoperative difficulties the PCA was performed on the PT.

Conclusions

A temporary R‐PCA represents a feasible alternative method of portal decompression during LT. Its use can be implemented into the technical armamentarium of transplant surgeons.
Increased chalcopyrite bioleaching capabilities of extremely thermoacidophilic Metallosphaera sedula inocula by mixotrophic propagation
Authors: Ai Chenbing , Yan Zhang , Chai Hongsheng , Gu Tianyuan , Wang Junjun , Chai Liyuan , Qiu Guanzhou , Zeng Weimin
Published: June 2019

Extremely thermoacidophilic Crenarchaeota belonging to the order Sulfolobales, such as Metallosphaera sedula, are metabolically versatile and of great relevance in bioleaching. However, the impacts of extreme thermoacidophiles propagated with different energy substrates on subsequent bioleaching of refractory chalcopyrite remain unknown. Transcriptional responses underlying their different bioleaching potentials are still elusive. Here, it was first showed that M. sedula inocula propagated with typical energy substrates have different chalcopyrite bioleaching capabilities. Inoculum propagated heterotrophically with yeast extract was deficient in bioleaching; however, inoculum propagated mixotrophically with chalcopyrite, pyrite or sulfur recovered 79%, 78% and 62% copper, respectively, in 12 days. Compared with heterotrophically propagated inoculum, 937, 859 and 683 differentially expressed genes (DEGs) were identified in inoculum cultured with chalcopyrite, pyrite or sulfur, respectively, including upregulation of genes involved in bioleaching-associated metabolism, e.g., Fe2+ and sulfur oxidation, CO2 fixation. Inoculum propagated with pyrite or sulfur, respectively, shared 480 and 411 DEGs with chalcopyrite-cultured inoculum. Discrepancies on repertories of DEGs that involved in Fe2+ and sulfur oxidation in inocula greatly affected subsequent chalcopyrite bioleaching rates. Novel genes (e.g., Msed_1156, Msed_0549) probably involved in sulfur oxidation were first identified. This study highlights that mixotrophically propagated extreme thermoacidophiles especially with chalcopyrite should be inoculated into chalcopyrite heaps at industrial scale.
Deflationism and truthmaking
Authors: Simpson Matthew
Published: June 2019

This paper is about the relationship between truthmaking—one of the pillars of contemporary metaphysics—and deflationism about truth—one of the main contenders in the debate about truth, and a key component of the broad anti-metaphysical philosophical approach known as (contemporary) pragmatism. Many philosophers have argued that deflationism and truthmaking are incompatible or in conflict in some interesting way. Some take this to count against deflationism, others to count against truthmaking. In this paper I argue that deflationism and truthmaking are compatible in most of the ways in which they are commonly thought to be incompatible. Deflationism does not render truthmaking unintelligible, avoidable, unmotivated, or trivial. While deflationism is incompatible with certain ideas within mainstream truthmaking, I argue that these ideas result from merely optional assumptions and principles commonly accepted by mainstream truthmaker theorists.
Measuring the effectiveness of psychoeducation on adherence, depression, anxiety and stress among patients with diagnosis of schizophrenia. a control trial
Authors: Alizioti Apostolia , Lyrakos Georgios
Published: June 2019

Despite evidence of the impact of depression and stress on attitudes towards medication in general medical pathology regimens, little is known of the effects of depression and stress on attitudes towards medication in schizophrenia. This study explores the effects of a hope-based psychoeducation on attitudes towards medication, depression, anxiety and stress, and predictors of attitudes towards medication. The participants in the study (n = 29) were randomly allocated to either the psychoeducation group or the control group. Results from the psychoeducation group revealed that attitudes towards medication were significantly improved and anxiety was significantly reduced. Given the small sample, which was recruited from among patients of a day mental health centre, findings should be interpreted tentatively. Being longer in pharmacotherapy, having experienced fewer occurrences of hospitalisation, and being less depressed predicted positivity towards medication. Patients in the control group did not exhibit significant change in any of the studied variables. Findings were interpreted in the light of research on stigma and insight into illness, and add modestly to literature arguing for the importance of patients’ retention of hope, empowerment and sense of control over illness. This study proposed that psychoeducation is an appropriate intervention to address a wide range of factors that compound adherence to medication and patients’ symptoms, such as patients’ interpretations of causal models, their sense of hope and control over the illness, and their insight into illness and self-stigma.
School environment, physical activity, and sleep as predictors of suicidal ideation in adolescents: Evidence from a national survey
Authors: Pfledderer Christopher D. , Burns Ryan D. , Brusseau Timothy A.
Published: June 2019

Introduction

Suicide is the second leading cause of death among individuals between 10 and 34 years of age and suicidal ideation substantially increases during adolescence. The purpose of this study was to examine the associations among physical activity, sleep, and factors relating to the school environment with adolescent self‐reported rates of suicidal ideation on the 2017 National Risk Behavior Survey (YRBS).

Methods

A multi‐stage cluster sampling procedure was employed to yield a representative sample of US adolescents recruited from the 9th through 12th grade. The number of sampled adolescents was 18,324 with 10,125 students submitting questionnaires with useable data for this study. Weighted logistic regression models were employed to examine the predictive utility of physical activity, sleep, and factors related to the school environment with suicidal ideation, adjusting for age, sex, and BMI percentile.

Results

Meeting physical activity guidelines every day of the week (OR 0.62, 95% CI: 0.51–0.76), hours of sleep (OR 5.46, 95% CI: 4.21–7.09), and factors relating to the school environment including bringing weapons to school (OR 2.06, 95% CI: 1.24–3.41), perceived school safety (OR 1.59, 95% CI: 1.27–2.00), and being bullied (OR 3.23, 95% CI: 2.71–3.87) and buying illegal drugs at school (OR 1.92, 95% CI: 1.63–2.27) all significantly independently predicted suicidal ideation.

Conclusions

Physical activity, sleep, and the school environment significantly predict suicidal ideation among this national sample of adolescents. These factors should be considered when designing interventions or programs to reduce the risk of suicidal ideation among adolescents.
P.002 Quality of life across types of dementia in rural and remote memory clinic patients
Authors: Kushneriuk M , Kirk A , Karunanayake C , Morgan DG , O’Connell ME
Published: June 2019

Background: Quality of life (QOL) is of great importance in dementia. We examined QOL across types of dementia in patients presenting to a rural and remote memory clinic (RRMC). Methods: This analysis included 343 RRMC patients seen between 2004 and 2016. Patients were diagnosed with mild cognitive impairment (MCI, n=74), frontotemporal dementia (FTD, n=42), Alzheimer’s disease (AD, n=187), vascular dementia (VD, n=22), or Lewy Body dementia (DLB, n=18). Patients and caregivers completed questionnaires at their initial visit. Data collection included patient-rated patient QOL (QOL-PT), caregiver-rated patient QOL (QOL-CG), MMSE score, age, and other patient demographics. Statistical analysis assessed patient variables and differences in QOL across types of dementia using one-way ANOVA, χ2 tests, and t-tests. Results: QOL-PT did not differ by diagnosis, whereas QOL-CG did. QOL-CG was significantly higher in MCI (34.6±7.1) compared to FTD (30.9±5.2) and AD (31.7±5.9). QOL-PT and QOL-CG differed in certain dementia types. QOL-PT was significantly higher than QOL-CG in MCI (QOL-PT=37.3±5.0, QOL-CG=35.3±7.3), FTD (QOL-PT=37.2±6.1, QOL-CG=31.7±5.5), and AD (QOL-PT=37.0±9.7, QOL-CG=32.1±5.9). Conclusions: We found that QOL-PT does not differ across dementia types, QOL-CG is higher in MCI compared to FTD and AD, and patients rate their own QOL higher than their caregivers do in MCI, FTD, and AD.
P.006 Efficacy of adjunctive brivaracetam in adult patients with secondarily generalized tonic-clonic seizures at baseline: pooled results from long-term follow-up trials
Authors: Moseley BD , Diaz A , Elmoufti S , Whitesides J
Published: June 2019

Background: Previous post-hoc analysis of three 12-week, double-blind, placebo-controlled trials showed adjunctive brivaracetam (BRV) reduced focal and secondarily generalized tonic-clonic seizures (SGTCS; Type IC) in patients with baseline SGTCS. This analysis explored long-term efficacy of adjunctive BRV in these patients. Methods: Patients (≥16 years) with focal seizures with SGTCS at Baseline were identified from 12-week double-blind, placebo-controlled trials (NCT00490035/NCT00464269/NCT01261325) and subsequent open-label, long-term follow-up (LTFU) trials (NCT00175916/NCT00150800/NCT01339559). Outcomes were assessed at protocol-specified time-points (up to 60 months). We report post-hoc efficacy data for patients receiving BRV (50–200 mg/day). Results: At double-blind Baseline, 409 patients had SGTCS (mean epilepsy duration: 22.2 years); 28.4%, 38.9%, and 32.8% had 0–1, 2–4, and ≥5 previous AEDs. Baseline median seizure frequency/28 days was 8.1 (focal) and 3.0 (SGTCS only). 325/409 patients (79.5%) entered LTFU. In the 12-month (n=150), 24-month (n=89), 36-month (n=73), 48-month (n=68) and 60-month (n=57) exposure cohorts, median percent reduction from Baseline in SGTCS frequency/28 days was 81.1%, 84.0%, 89.2%, 91.0%, and 90.6%, respectively. ≥50% responder rates for SGTCS were 75.3%, 78.7%, 80.8%, 79.4%, and 78.9%. No safety concerns were identified. Conclusions: Adjunctive BRV (50–200 mg/day) reduced SGTCS frequency during LTFU (up to 60 months) in patients with SGTCS at Baseline.
P.019 Motor evoked potentials as a new biomarker in multiple sclerosis
Authors: Jacques FH , Fortin J , Lecompte M , Foko V Sikati , Apedaile E
Published: June 2019

Background: Motor evoked potentials (MEP’S) measure myelin/axonal integrity of the central nervous system. MEP’s reliability and correlation to conventional clinical measures in multiple sclerosis (MS) patients have yet to be demonstrated. Alemtuzumab is a high efficacy therapy used in patients with MS. Its longitudinal impact on electrophysiological measures has yet to be examined. Methods: This is a single center, observational study. 10 patients with MS who received their first cycle of alemtuzumab within less than 3 months were evaluated with both clinical and MEP’s measures at baseline and every 6 months thereafter for 36 months. MEP’s were repeated two weeks after every time point. We report our preliminary analyses. Results: Patient follow-up ranges from 6 to 36 months. The intraclass correlation coefficient (ICC) between two consecutive time points were good with values of 0.774 for the biceps and 0.867 for the tibialis anterior with p values less than 0.0005 for both. The correlation for the biceps MEP’s to the 9 hole peg test (9HPT) was 0.51 with p less than 0.0005 and for the tibialis anterior MEP’s to the 6 minute walk test (6MWT) was -0.411 with p=0.01. Conclusions: Our preliminary analyses demonstrate that MEP results are reproducible and correlate with clinical measures.
P.030 The journey with CIDP- a Canadian perspective
Authors: Hartlen D , Mikhail T
Published: June 2019

Background: Chronic Inflammatory demyelinating polyradiculoneuropathy is a rare disorder of the peripheral nerves. A disease affecting up to 8.9 out of 100,000 people, and a yearly incidence of 1.6/100,000 people, CIDP is a condition that is treatable but still relatively unknown outside of the neuromuscular community. The purpose of this research, initiated by the GBS/CIDP Foundation, is to better understand a patient’s journey living with the disease and identify unmet needs. Methods: The research consists of a mix of structured interviews, digital ethnography and patient records. A total of 10 Canadian patients living with CIDP and their caregivers, 7 Canadian neurologists and 3 Canadian neuroscience nurses will be the subjects for our research. Results: In order to identify key interactions between patients and the healthcare system, the report will map a patient’s experience on 4 distinct planes. Clinical journey (ex: first symptoms, diagnosis, disease progression), Patient emotional journey (the emotional states the patient undergoes throughout his/her journey), Caregiver emotional journey, and Outcomes (ex: delays in care, damaged relationships, commitment to therapy). The report will identify key areas along the patient journey where more intervention is possible and where more research may be needed. Conclusions: The research is expected to be completed by April 2019.
P.042 Safety and efficacy of stereoelectroencephalography in pediatric epilepsy surgery
Authors: Elliott CA , Narvacan K , Kassiri J , Carline S , Wheatley B , Sinclair D
Published: June 2019

Background: There are few published reports on the safety and efficacy of stereoelectroencephalography (SEEG) in the presurgical evaluation of pediatric drug-resistant epilepsy. Our objective was to describe institutional experience with pediatric SEEG in terms of (1) insertional complications, (2) identification of the epileptogenic zone and (3) seizure outcome following SEEG-tailored resections. Methods: Retrospective review of 29 patients pediatric drug resistant epilepsy patients who underwent presurgical SEEG between 2005 – 2018. Results: 29 pediatric SEEG patients (15 male; 12.4 ± 4.6 years old) were included in this study with mean follow-up of 6.0 ± 4.1 years. SEEG-related complications occurred in 1/29 (3%)—neurogenic pulmonary edema. A total of 190 multi-contact electrodes (mean of 7.0 ± 2.5per patient) were implanted across 30 insertions which captured 437 electrographic seizures (mean 17.5 ± 27.6 per patient). The most common rationale for SEEG was normal MRI with surface EEG that failed to identify the EZ (16/29; 55%). SEEG-tailored resections were performed in 24/29 (83%). Engel I outcome was achieved following resections in 19/24 cases (79%) with 5.9 ± 4.0 years of post-operative follow-up. Conclusions: Stereoelectroencephalography in presurgical evaluation of pediatric drug-resistant epilepsy is a safe and effective way to identify the epileptogenic zone permitting SEEG-tailored resection.
P.055 A clinical pathway of combined EEG monitoring in high-risk critically ill neonates
Authors: Mendelsohn R , Pohl D , Mabilangan K , Lemyre B
Published: June 2019

Background: overtreatment of neonatal seizures may result in neurological morbidity. aEEG, despite low sensitivity, is widely used, for ease of bedside interpretation. vEEG, is a limited resource needing expert interpretation. We hypothesize that using aEEG combined with vEEG will increase the sensitivity and specificity of seizure detection and reduce anti-convulsants use compared to aEEG alone. Methods: Prospective cohort of neonates admitted to CHEO NICU with suspected seizures between April 1st 2018 to present. Seizures (clinical/aEEG) were documented by bedside clinicians and compared to the vEEG. Bedside clinicians could call a neurologist for remote review of the vEEG. Outcomes include concordance of aEEG and vEEG events and number of episodes where management was changed based on both readings Results: 27 patients had both modalities recording simultaneously. No seizure was identified by either modality in 23 recordings. Seizures were identified in 4 vEEG recordings; the aEEG partially identified these seizures.

aEEG specificity of 0.87, negative predictive value 0.8, sensitivity 0.44 and positive predictive value 0.57

Bedside clinician contacted a neurologist 9 times; in 2 cases, this prevented unnecessary treatment.

Conclusions: In this small sample, aEEG had good specificity for ruling out seizures, but low sensitivity for detecting them. The new combined pathway may prevent unnecessary treatment.
P.069 Pediatric neurology subspecialty education development in a resource limited setting
Authors: Mineyko A , Day L , Kumbakumba E , Santorino D , Boctor D
Published: June 2019

Background: In 2013, the University of Calgary (UofC) - Mbarara University of Science and Technology (MUST) Pediatric Education Program was established when the Pediatric Department in Mbarara, Uganda identified a need for enhanced education in pediatric subspecialty areas. We report on the experience of developing the pediatric neurology subspecialty curriculum. Methods: Pre-visit meetings established mutually agreed upon objectives and learning activities that were implemented over 2-week periods in 2015 and 2018. Pre and post-tests were administered to MUST Pediatric residents. Mean differences in test scores were compared using a Student t-test. Residents provided written feedback following the end of the second visit. Results: A pediatric neurologist (AM) visited MUST (2015 and 2018) to deliver the curriculum. The second visit was accompanied by a senior UofC Pediatrics resident (LD). Eight and 14 residents at MUST participated in the curriculum in 2015 and 2018, respectively. Neurology test scores improved in 2015 from a mean of 43% to 61% (p = 0.011) and in 2018 from 53% to 84% (p < 0.00001). Teaching sessions were well received by MUST residents. Conclusions: Collaboration between UofC faculty and MUST established an effective pediatric neurology curriculum that was well-received by residents.
P.073 Improving access to urgent neurology care for pediatric patients
Authors: Yaworski A , Yager J , Mailo J , Richer L , Rajapakse T , Kassiri J
Published: June 2019

Background: Pediatric neurology referral wait times are increasing, often leading to emergency department (ED) utilization. On average 5% of ED patients present with neurological symptoms and 35% of ED neurological diagnoses are revised after specialist review. A Stollery Rapid Access Neurology (RAN) clinic was created to decrease wait time, and initiate an efficient referral process. Methods: The RAN clinic ran weekly from March 2018 until February 2019. This was a prospective study approved by the University of Alberta ethics board. Inclusion criteria were met. Information was collected for diagnosis, along with confidential patient satisfaction surveys. Results: Seventy-five patients were referred, 49% from the ED. Wait time averaged 6 weeks. The most frequent referral reason was seizures, with 60% of referring diagnosis being correct. Prior to RAN appointment, 61% of patients presented to the ED, whereas only 0.1% returned in the following 3 months. Neurology follow up was required in 81% of patients. Overall satisfaction was ranked 9.6/10. Conclusions: The RAN clinic created an effective urgent triage method. Neurologist review revised 40% of diagnoses. This ongoing study reveals that a RAN clinic can reduce visits to the ED following appointment and initiate appropriate follow up. Future evaluation in cost effectiveness and telehealth appointments are required.
P.097 Metabolomic and lipidomic profiling of high and low grade gliomas - a matched serum and tissue clinical study
Authors: Khan OH , Agnihotri S
Published: June 2019

Background: It is well understood that gliomas require vast supply of energy to proliferate, invade and spread. We wished to identify novel biomarkers by comparing normal brain and plasma to high and low grade gliomas using newer techniques in laser ionization mass spectroscopy - precision metabolomics and lipidomics. Methods: Single center IRB approved tissue bank of “normal” brain and plasma (n=6) and IDH wild-type GBM tissue and plamsa (n=29), IDH mutant GBM tissue and plamsa (n=6), Low grade glioma (n=4) tissue and plamsa were analyzed for over 2000 endogenous metbolites and complex lipids. Unbiased clustering and Random Forest plots and pathway analysis were performed with appropriate statsitical analysis (significance p < 0.05). Results: IDH mutant GBM had higher levels of 2-HG, however, plasma 2-HG did not reflect IDH genotype. Changes in glucose and fatty acid utilization were observed in IDH WT and mutant gliomas compared to normal brain tissue. Lipidomics of plasma and tissue of normal and gliomas did not reveal a biomarker reaching statistical significance. Conclusions: We will continue to investigate if plasma and tissue biomarkers including hypotaurine, methionine, branched chain amino acid catabolites and pregnonolone can be used to predict tumor progression, response to treatment and clinical outcomes.
P.098 Novalis Certification of stereotactic radiosurgery programs: methodology and current status
Authors: Pickett GE , Robar JL
Published: June 2019

Background: The Novalis Certification Program is dedicated to providing a comprehensive and independent assessment of safety and quality in stereotactic radiosurgery (SRS). Methods: The program includes an independent review of SRS program structure, adequacy of personnel resources and training, appropriateness and use of technology, program quality management, patient-specific quality assurance and equipment quality control. Centres applying for Novalis Certification complete a self-study prior to a one-day visit by reviewers. Reviewers generate a descriptive 77-point report which is voted on by a multidisciplinary expert panel. Outcomes of reviews include mandatory requirements and optional recommendations, with the former requiring resolution prior to award of Certification. Sites undergo recertification every 4 years. Results: To date, 42 institutions have received Novalis Certification. A further 140 certification applications are pending. Two sites have been recertified, with 4 more in process this year. Analysis of review outcomes identified improved documentation of procedures as a frequent requirement, while frequent recommendations pertain to equipment/systems QA procedures and effective use of checklists/time outs. Conclusions: Novalis Certification is a unique, expanding peer review program assessing safety and quality in SRS and recognizing a high caliber of practice internationally. The standards-based approach highlights outstanding requirements and provides recommendations to enhance both new and established programs.
P.099 Integrating DNA methylation profiling in brain tumour diagnosis directly changes patient oncological care
Authors: Zuccato JA , Karimi S , Mansouri S , Mamatjan Y , Suppiah S , Diamandis P , Aldape KD , Zadeh G
Published: June 2019

Background: Molecular signatures are being increasing used to classify central nervous system (CNS) tumors with incorporation into World Health Organization (WHO) classifications. A recently published genome-wide DNA methylation-based CNS tumor classifier assisted in diagnostically challenging cases. However its impact on patient care has not been reported, limiting translation to other centres. Methods: All 55 challenging CNS tumour diagnoses over three years underwent DNA methylation profiling. Tumor classification along with copy number variant (CNV) plot results were integrated with histopathological findings to determine final diagnoses and corresponding clinical impact was assessed. Results: After methylation profiling 46/55 (84%) received clinically relevant diagnostic changes, 30 (55%) with a new diagnosis or resolved differential diagnosis and 16 (29%) with clinically important molecular diagnostic or subtyping changes. WHO grade changed in 15 (27%), with two-thirds upgraded. Nine new IDH mutations in gliomas, four new molecular subtypes in medulloblastomas/ependymomas, and three false positive 1p/19q codeletions were identified. Patient care was directly changed by methylation profiling in 7/47 (15%) followed-up cases to avoid unnecessary treatment in three, insufficient treatment in three, and medically assisted death in one. Conclusions: This real-world use of methylation-based CNS tumor classification substantially impacts patient care for diagnostically challenging tumors and also avoids misdiagnosis-related uncessary resource use.
P.103 When a neurosurgeon should care about pneumonia: the case for Pneumocystis jirovecii pneumonia prophylaxis in neurosurgical patients
Authors: de Lotbiniere-Bassett M , Dhillon M , Boiteau PJ , Couillard P
Published: June 2019

Background: Pneumocystis jirovecii pneumonia (PJP) is an opportunistic interstitial fungal pneumonia. The incidence of PJP in HIV-positive populations is decreasing, while it is increasing in HIV-negative immunocompromised populations, such as neurosurgical patients treated with high-dose corticosteroids. Morbidity and mortality can be severe owing to acute respiratory failure. Methods: Two cases are described and a literature review performed to determine the incidence of PJP in the neurosurgery population. A standardized care pathway is proposed to reduce preventable harm. Results: Long-term, high-dose corticosteroid regimens (≥4 mg dexamethasone daily for ≥4 weeks) with taper are associated with increased risk of PJP infection. Additional risk factors for infection in HIV-negative patients include CNS malignancy and concurrent radiation therapy. TMP-SMX is the first-line agent for PJP prophylaxis. Conclusions: Clinicians should maintain a high index of suspicion of PJP and adopt a standardized protocol for prophylaxis in neurosurgical patients treated with high-dose corticosteroids.
P.113 Case series, systematic review and meta-analysis of basilar bifurcation aneurysms treated between 2001 – 2017
Authors: Dandurand C , Prakash S , Sepehry A , Tourigny K , Haw CS , Gooderham PA , Redekop G
Published: June 2019

Background: In aneurysms overall, a lower rate of recanalization in stent assisted coiling vs coiling alone has been observed without an increase in morbidity. This study aims to stratify and compare degree of occlusion outcome by treatment modalities. Secondarily, this study aims to stratify and compare postoperative adverse events. Methods: MEDLINE and EMBASE databases were searched. Study center were reviewed for inclusion. We performed meta-regressions, bias analysis and fail-safe N. We controlled for the quality of the studies. Results: 396 nonduplicated patients were separated into 4 groups: microsurgical, stent-assisted coiling, coiling, stent only. Stent-assisted coiling has lower rate of retreatment (17 vs 24%) and higher rehemorrhage (5% vs 3%) compared to coiling. Stent-assisted has higher rates of complete occlusion (55% vs 45%) and lower rate of residual aneurysm (15% vs 23%) compared to coiling. Comparative analyses were performed. Microsurgical remained the most morbid modality with the best rate of complete occlusion (93%) and lowest rehemorrhage (2%) and retreatment rate (5%). Conclusions: This is the first and largest meta-analysis focusing on patients treated for basilar apex aneurysm. To our knowledge, this is the first study to stratify and compare degree of occlusion per treatment modality. This study provides benchmark numbers to guide clinicians.
P.115 Saskatchewan experience with mechanical thrombectomy under general anaesthesia
Authors: Persad A , Tymchak Z , Ahmed S , Gardner A , Whelan R , Kelly ME , Peeling L
Published: June 2019

Background: While recent clinical trials have demonstrated immense efficacy of mechanical thrombectomy (MT) in the setting of acute stroke, there remains debate over the safety in performing this procedure under general anesthesia (GA). In the Saskatchewan Acute Stroke Pathway, all patients presenting with LVO have endovascular thrombectomy performed under GA. Methods: Data was retrospectively reviewed on 108 consecutive LVO in 2016-2017. All MT were done under GA. Anatomical location of LVO, pre-MT ASPECTS score, post-MT TICI scores and 90-day NIHSS and mRS were recorded. Results: Of 108 LVO, 103 went on to have MT. 44 were right anterior circulation, 50 were left anterior circulation and 9 were posterior circulation. Of 94 anterior circulation strokes, 47 (50.0%), 43 (45.7%) and 4 (4.3%) had good, moderate and poor collateral circulation respectively, and the average pre-MT ASPECTS was 8.6. The average pre-MT NIHSS was 14.7. 81/90 (90.0%) achieved thrombolysis in cerebral infarction (TICI) perfusion scale grade of 2b/3 after recanalization. Average documented 90-day NIHSS was 2.4 and mRS was 2.5. Overall mortality was 21/103 (20.4%). Conclusions: In the Saskatchewan acute stroke pathway, general anesthesia is a safe modality for MT. This adds to the body of evidence supporting GA as a viable option for sedation in MT.
P.122 The prediction of outcome after shunting for idiopathic normal pressure hydrocephalus
Authors: Daud Shah B , Persad A , Meguro K
Published: June 2019

Background: Idiopathic normal pressure hydrocephalus (iNPH) is a triad of impaired gait, cognition and urinary control in the setting of normal pressure ventriculomegaly. Various options for shunt implantation exist, but there is limited ability to predict outcome. Methods: This study is a retrospective chart review of 82 shunted patients for iNPH between 2007 and 2018. Factors examined included age, sex, lumbar puncture results, use of laparoscopic approach, type of shunt used, Charlson Comorbidity Index and imaging (callosal angle and DESH). Patient outcome was assessed via modified Rankin Scale (mRS). Results: 52 patients were male and 30 were female. Average age at surgery was 71.4 years. 58/62 (94%) improved following lumbar puncture. 41% of patients had VP shunt, and 59% of patients had LP shunt. 30/79 (38%) had laparoscopic placement of the distal catheter. 23/75 (31%) and 30/81 (36%) had a complication and required reoperation, respectively. Callosal angle showed statistically significant increase post-shunting (76 to 94 degrees, p<0.005). Presence of DESH did not change post-shunting. Average Charlson Comorbidity Index was 4.4. The mRS decreased from 3.84 to 2.66 post-operatively (p<0.005). Conclusions: In our centre, iNPH patients had clinicoradiologic improvement following shunting. We will perform regressional statistics to elucidate the factors influencing outcomes.