bluuebunny/crossref_metadata_2025_split huggingface dataset:
Construct validity of cadaveric temporal bones for training and assessment in mastoidectomy
Authors: Awad Zaid , Tornari Chrysostomos , Ahmed Shahanaz , Tolley Neil S. 
Published: April 2015

ObjectiveTo determine the construct validity of cadaveric temporal bones in mastoidectomy training.Study DesignA prospective observational study.MethodsTrainees from the North London otolaryngology training program performed step‐wise modified radical mastoidectomy on cadaveric temporal bones under faculty supervision. Performance was assessed using a validated mastoidectomy assessment tool. A longitudinal assessment of nine trainees was also carried out over two sessions separated by 12 months. The main outcomes measures were task‐specific (TS) and global skills (GS).ResultsTwenty‐six intermediate and eight novice trainees participated and were assessed by a minimum of two assessors each. Intermediate trainees performed significantly better than novices in TS and GS (P < 0.001). Performance correlated well with training level using Spearman rank correlation coefficient (rs) (TS rs 0.265 and GS rs 0.503). The number of otological procedures performed, and in particular mastoidectomies, correlated well with performance (TS rs 0.327 and GS rs 0.528). Longitudinal assessment showed significant improvement with iteration (TS P = 0.008 and GS P = 0.008). Attending otological courses also improved performance significantly (TS rs 0.345 and GS rs 0.469).ConclusionsThe cadaveric temporal bone demonstrated construct validity and can be used to detect progress in performance of otolaryngology trainees. This is a keystone in moving toward a competency‐based training system.Level of EvidenceN/A. Laryngoscope, 125:2376–2381, 2015
Value and discriminative power of the seven‐item eustachian tube dysfunction questionnaire
Authors: Van Roeyen Shari , Van de Heyning Paul , Van Rompaey Vincent 
Published: April 2015

Objectives/HypothesisObstructive eustachian tube (ET) dysfunction is a common condition associated with various otologic symptoms. The current lack of a diagnostic gold standard makes diagnosis and evaluation at follow‐up difficult. The aim of the study was to determine the value and discriminative power of the seven‐item Eustachian Tube Dysfunction Questionnaire (ETDQ‐7) in patients with obstructive ET dysfunction and patulous ET.Study designDiagnostic test study.MethodsThe ETDQ‐7 was completed by 39 patients with obstructive ET dysfunction, eight patients with patulous ET, and 22 healthy controls. The internal consistency was evaluated using the Cronbach α coefficient. Receiver operating characteristic (ROC) was determined as an accuracy measure.ResultsThe mean ETDQ‐7 total score was 9.91 in the control group, 25.77 in the patients with obstructive ET dysfunction, and 27 in the patulous ET group. The Cronbach α coefficient was 0.795 in the obstructive ET group and 0.72 in the patulous ET group, demonstrating adequate reliability. The area under the curve in ROC analysis for the obstructive ET group was 95% and 96% for the patulous ET dysfunction group, which confirms its excellent discriminant validity toward the healthy control group. However, the ETDQ‐7 cannot discriminate between obstructive ET dysfunction and patulous ET.ConclusionsThe ETDQ‐7 can be a useful disease‐specific rating scale for ET dysfunction but is unable to discriminate between patients with obstructive ET dysfunction and patulous ET.Level of Evidence3b Laryngoscope, 125:2553–2556, 2015
Psychological effects of dysphonia in voice professionals
Authors: Salturk Ziya , Kumral Tolgar Lutfi , Aydoğdu Imran , Arslanoğlu Ahmet , Berkiten Güler , Yildirim Güven , Uyar Yavuz 
Published: April 2015

Objectives/HypothesisTo evaluate the psychological effects of dysphonia in voice professionals compared to non–voice professionals and in both genders.Study DesignCross‐sectional analysis.MethodsForty‐eight 48 voice professionals and 52 non–voice professionals with dysphonia were included in this study. All participants underwent a complete ear, nose, and throat examination and an evaluation for pathologies that might affect vocal quality. Participants were asked to complete the Turkish versions of the Voice Handicap Index‐30 (VHI‐30), Perceived Stress Scale (PSS), and the Hospital Anxiety and Depression Scale (HADS). HADS scores were evaluated as HADS‐A (anxiety) and HADS‐D (depression). Dysphonia status was evaluated by grade, roughness, breathiness, asthenia, and strain (GRBAS) scale perceptually. The results were compared statistically.ResultsSignificant differences between the two groups were evident when the VHI‐30 and PSS data were compared (P = .00001 and P = .00001, respectively). However, neither HADS score (HADS‐A and HADS‐D) differed between groups. An analysis of the scores in terms of sex revealed that females had significantly higher PSS scores (P = .006). The GRBAS scale revealed no difference between groups (P = .819, .931, .803, .655, and .803, respectively). No between‐sex differences in the VHI‐30 or HADS scores were evidentConclusionsWe found that voice professionals and females experienced more stress and were more dissatisfied with their voices.Level of Evidence4. Laryngoscope, 125:1908–1910, 2015
Slowing Down of Ring Polymer Diffusion Caused by Inter‐Ring Threading
Authors: Lee Eunsang , Kim Soree , Jung YounJoon 
Published: April 2015

Diffusion of long ring polymers in a melt is much slower than the reorganization of their internal structures. While direct evidence for entanglements has not been observed in the long ring polymers unlike linear polymer melts, threading between the rings is suspected to be the main reason for slowing down of ring polymer diffusion. It is, however, difficult to define the threading configuration between two rings because the rings have no chain end. In this work, evidence for threading dynamics of ring polymers is presented by using molecular dynamics simulation and applying a novel analysis method. The simulation results are analyzed in terms of the statistics of persistence and exchange times that have proved useful in studying heterogeneous dynamics of glassy systems. It is found that the threading time of ring polymer melts increases more rapidly with the degree of polymerization than that of linear polymer melts. This indicates that threaded ring polymers cannot diffuse until an unthreading event occurs, which results in the slowing down of ring polymer diffusion.image
Size‐Controlled Fabrication of Polyaniline Microfibers Based on 3D Hydrodynamic Focusing Approach
Authors: Yoo Imsung , Song Simon , Uh Kyungchan , Lee Chan Woo , Kim Jong‐Man 
Published: April 2015

Owing to the relatively high conductivity and unique redox behavior, polyaniline (PANI) has been one of the most technologically promising conducting polymers. Although various methodologies have been developed, fabrication of PANI microfibers has been a challenging task owing to the poor solubility in most organic solvents. By taking advantage of a microfluidic technology and organic soluble acid labile t‐Boc‐protected PANI (t‐Boc‐PANI) as the conducting polymer precursor, fabrication of PANI microfibers in a size‐controlled manner is possible. Introduction of a THF solution containing t‐Boc‐PANI, and dodecylbenzenesulfonic acid (DBSA) as a core flow, and water as a sheath flow into a microfluidic channel with a 3D hydrodynamic focusing effect results in crystallization of the polymer fiber. By changing the flow rate, linear PANI microfibers that range from 16.2 to 39.4 μm in diameter are readily obtained.
image
Water‐Assisted Vapor Deposition of PEDOT Thin Film
Authors: Goktas Hilal , Wang Xiaoxue , Ugur Asli , Gleason Karen K. 
Published: April 2015

The synthesis and characterization of poly(3,4‐ethylenedioxythiophene) (PEDOT) using water‐assisted vapor phase polymerization (VPP) and oxidative chemical vapor deposition (oCVD) are reported. For the VPP PEDOT, the oxidant, FeCl3, is sublimated onto the substrate from a heated crucible in the reactor chamber and subsequently exposed to 3,4‐ethylenedioxythiophene (EDOT) monomer and water vapor in the same reactor. The oCVD PEDOT was produced by introducing the oxidant, EDOT monomer, and water vapor simultaneously to the reactor. The enhancement of doping and crystallinity is observed in the water‐assisted oCVD thin films. The high doping level observed at UV–vis–NIR spectra for the oCVD PEDOT, suggests that water acts as a solubilizing agent for oxidant and its byproducts. Although the VPP produced PEDOT thin films are fully amorphous, their conductivities are comparable with that of the oCVD produced ones.
image
SAXS Analysis of Shell Formation During Nanocapsule Synthesis via Inverse Miniemulsion Periphery RAFT Polymerization
Authors: Utama Robert H. , Dulle Martin , Förster Stephan , Stenzel Martina H. , Zetterlund Per B. 
Published: April 2015

Currently available methods for synthesis of polymeric nanocapsules only offer limited control over the shell thickness, even though it is an important parameter for various applications. Furthermore, suitable methods to critically measure this parameter in a facile way are still nonexistent. Here, lab‐scale small‐angle X‐ray scattering (SAXS) is utilized to in situ measure the evolution of shell thickness during nanocapsule synthesis via inverse miniemulsion periphery reversible addition–fragmentation chain transfer (RAFT) polymerization (IMEPP). The measured shell thickness is consistent with estimates from the commonly used transmission electron microscopy (TEM) technique. Moreover, the individual thicknesses of two concentric shells comprising different polymeric materials (the outer shell formed via IMEPP chain extension of the inner shell) can be determined, thus further demonstrating the versatility of this approach.
image
Comparison of muscle BOLD responses to arterial occlusion at 3 and 7 Tesla
Authors: Towse Theodore F. , Childs Benjamin T. , Sabin Shea A. , Bush Emily C. , Elder Christopher P. , Damon Bruce M. 
Published: April 2015

PurposeThe purpose of this study was to determine the feasibility of muscle BOLD (mBOLD) imaging at 7 Tesla (T) by comparing the changes in R2* of muscle at 3 and 7T in response to a brief period of tourniquet‐induced ischemia.MethodsEight subjects (three male), aged 29.5 ± 6.1 years (mean ± standard deviation, SD), 167.0 ± 10.6 cm tall with a body mass of 62.0 ± 18.0 kg, participated in the study. Subjects reported to the lab on four separate occasions including a habituation session, two MRI scans, and in a subset of subjects, a session during which changes in blood flow and blood oxygenation were quantified using Doppler ultrasound (U/S) and near‐infrared spectroscopy (NIRS) respectively. For statistical comparisons between 3 and 7T, R2* rate constants were calculated as R2* = 1/T2*.ResultsThe mean preocclusion R2* value was greater at 7T than at 3T (60.16 ± 2.95 vs. 35.17 ± 0.35 s−1, respectively, P < 0.001). Also, the mean ΔR2*END and ΔR2*POST values were greater for 7T than for 3T (−2.36 ± 0.25 vs. −1.24 ± 0.39 s−1, respectively, Table 1).ConclusionMuscle BOLD contrast at 7T is as much as six‐fold greater than at 3T. In addition to providing greater SNR and CNR, 7T mBOLD studies may offer further advantages in the form of greater sensitivity to pathological changes in the muscle microcirculation. Magn Reson Med 75:1333–1340, 2016. © 2015 Wiley Periodicals, Inc.
MPnRAGE: A technique to simultaneously acquire hundreds of differently contrasted MPRAGE images with applications to quantitative T1 mapping
Authors: Kecskemeti Steven , Samsonov Alexey , Hurley Samuel A. , Dean Douglas C. , Field Aaron , Alexander Andrew L. 
Published: April 2015

PurposeTo introduce a new technique called MPnRAGE, which produces hundreds of images with different T1 contrasts and a B1 corrected T1 map.Theory and MethodsAn interleaved three‐dimensional radial k‐space trajectory with a sliding window reconstruction is used in conjunction with magnetization preparation pulses. This work modifies the SNAPSHOT‐FLASH T1 fitting equations for radial imaging with view‐sharing and develops a new rapid B1 correction procedure. MPnRAGE is demonstrated in phantoms and volunteers, including two volunteers with eight scans each and eight volunteers with two scans each. T1 values from MPnRAGE were compared with those from fast spin echo inversion recovery (FSE‐IR) in phantoms and a healthy human brain at 3 Tesla (T).ResultsThe T1 fit for human white and gray matter was T1MPnRAGE = 1.00 · T1FSE‐IR + 24 ms, r2 = 0.990. Voxel‐wise coefficient of variation in T1 measurements across eight time points was between 0.02 and 0.08. Region of interest‐based T1 values were reproducible to within 2% and agree well with literature values.ConclusionIn the same amount of time as a traditional MPRAGE exam (7.5 min), MPnRAGE was shown to produce hundreds of images with alternate T1 contrasts as well as an accurate and reproducible T1 map that is robust to B1 errors. Magn Reson Med 75:1040–1053, 2016. © 2015 Wiley Periodicals, Inc.
Beneficial Effects of a Point‐of‐Care Bleeding Risk Calculator on Anticoagulant Selection in the Coronary Catheterization Laboratory
Authors: Kerl Jocelyn J. , Spexarth Frank C. , Pedersen Rachel , Stone Mia , Allaqaband Suhail Q. , Schulgit James L. , Bajwa Tanvir K. , Gupta Anjan N. , DeFranco Anthony C. 
Published: April 2015

Study ObjectivesTo estimate periprocedural bleeding risk before elective percutaneous coronary intervention (PCI) by using a point‐of‐care bleeding risk calculator and to document changes in anticoagulant use and bleeding complications after implementation of use of this calculator.DesignProspective observational pilot study with a historical control cohort.SettingTertiary care medical center.PatientsThe pilot cohort consisted of 100 patients undergoing ad hoc PCI during elective cardiac catheterization procedures between January and May 2013, whose bleeding risk and accompanying PCI anticoagulant recommendations were determined by the use of a pre‐PCI point‐of‐care bleeding risk calculator. The historical control cohort consisted of all patients who underwent elective PCI at the same facility between April 1, 2011, and March 31, 2012, before implementation of use of the bleeding risk calculator.Measurements and Main ResultsThe pre‐PCI bleeding risk calculator distinguished patients in the pilot cohort as high risk (score 12 or higher) or low risk (lower than 12) for bleeding after a PCI procedure. The primary outcome was bivalirudin use in the pilot cohort compared with its use in the historical control cohort. Implementation of the bleeding risk calculator significantly decreased bivalirudin use compared with bivalirudin use in the historical control cohort (87% in the control cohort vs 60% in the pilot cohort, p<0.01). Bivalirudin use remained high in patients at high bleeding risk (82.2% in the pilot cohort vs 87.4% in the control cohort, p=0.3) and its use was decreased in patients at low bleeding risk (41.8% in the pilot cohort vs 87.1% in the control cohort, p<0.01). The incidence of bleeding complications in the pilot cohort was comparable with that in the control cohort (1% vs. 0.4%, p=0.37), although this pilot study was underpowered to potentially detect a significant change in the incidence of bleeding complications.ConclusionA simple bleeding risk calculator can substantially reduce overall bivalirudin use by specifically decreasing its use among patients at low bleeding risk while maintaining its use among patients at high bleeding risk. The incidence of bleeding complications remained unchanged despite decreasing bivalirudin use among patients undergoing elective coronary catheterization who were at low risk for bleeding.
Autoinduction of Voriconazole Metabolism in a Child with Invasive Pulmonary Aspergillosis
Authors: Hsu Alice Jenh , Dabb Alix , Arav‐Boger Ravit 
Published: April 2015

Inter‐ and intra‐patient variability in voriconazole pharmacokinetics has been described in children as the result of age‐specific differences in hepatic metabolism, saturable nonlinear pharmacokinetics, CYP450 2C19 polymorphisms, decreased bioavailability compared with adults, and drug–drug interactions. We introduce dose‐dependent autoinduction of metabolism as another cause for altered voriconazole pharmacokinetics in children and summarize previously published literature on this phenomenon. A 10‐year‐old girl with severe aplastic anemia developed invasive pulmonary aspergillosis after high‐dose cyclophosphamide therapy and required high doses of voriconazole for longer than 2 months. She initially achieved a therapeutic trough of 1.4 μg/ml on voriconazole 11 mg/kg/dose orally every 12 hours but required dose escalations to 9.3 mg/kg/dose orally every 8 hours to maintain a trough above 1 μg/ml. Because there were no changes in concomitant medications, route of administration, adherence, or oral intake, we conclude that the only plausible explanation for the precipitous drop in voriconazole troughs was autoinduction of metabolism, a phenomenon previously reported in adults receiving higher than usual doses or prolonged courses (longer than 2 months). These data highlight the need for continued therapeutic drug monitoring of voriconazole after initial therapeutic troughs are achieved because autoinduction of metabolism can lead to significant declines in subsequent voriconazole troughs, potentially leading to treatment failure.
Rectal Propranolol Controls Paroxysmal Sympathetic Hyperactivity: A Case Report
Authors: May Casey C. , Oyler Douglas R. , Parli Sara E. , Talley Cynthia L. 
Published: April 2015

Paroxysmal sympathetic hyperactivity (PSH) affects approximately 10% of survivors of acquired brain injury and is associated with substantial morbidity. The most effective maintenance therapies include oral β‐blockers and α‐2 antagonists. We report the use of rectal propranolol for symptomatic control of PSH in a critically ill patient with an altered gastrointestinal tract for whom oral intake was contraindicated. A 15‐year‐old Caucasian male with no past medical history was admitted status post all‐terrain vehicle rollover with multiple intra‐abdominal injuries. On hospital day 40, the patient experienced cardiac arrest with a subsequent anoxic brain injury, which was complicated by the development of PSH on post‐arrest day 1. Because of his altered gastrointestinal tract, he was symptomatically managed with propranolol 40 mg per rectum every 6 hours in the form of specially prepared suppositories, intravenously infused morphine and dexmedetomidine, and a transdermal clonidine patch. The patient improved clinically during this treatment and was transferred to a rehabilitation facility. This is the first case report to describe successful use of propranolol suppositories in a clinical environment. This case supports the use of propranolol suppositories as a potential alternative route when oral administration is not possible.
Approach to Addressing Missing Data for Electronic Medical Records and Pharmacy Claims Data Research
Authors: Bounthavong Mark , Watanabe Jonathan H. , Sullivan Kevin M. 
Published: April 2015

ObjectiveThe complete capture of all values for each variable of interest in pharmacy research studies remains aspirational. The absence of these possibly influential values is a common problem for pharmacist investigators. Failure to account for missing data may translate to biased study findings and conclusions. Our goal in this analysis was to apply validated statistical methods for missing data to a previously analyzed data set and compare results when missing data methods were implemented versus standard analytics that ignore missing data effects.DesignUsing data from a retrospective cohort study, the statistical method of multiple imputation was used to provide regression‐based estimates of the missing values to improve available data usable for study outcomes measurement. These findings were then contrasted with a complete‐case analysis that restricted estimation to subjects in the cohort that had no missing values. Odds ratios were compared to assess differences in findings of the analyses. A nonadjusted regression analysis (“crude analysis”) was also performed as a reference for potential bias.SettingVeterans Integrated Systems Network that includes VA facilities in the Southern California and Nevada regions.PatientsNew statin users between November 30, 2006, and December 2, 2007, with a diagnosis of dyslipidemia.Main outcome measureWe compared the odds ratios (ORs) and 95% confidence intervals (CIs) for the crude, complete‐case, and multiple imputation analyses for the end points of a 25% or greater reduction in atherogenic lipids.ResultsData were missing for 21.5% of identified patients (1665 subjects of 7739). Regression model results were similar for the crude, complete‐case, and multiple imputation analyses with overlap of 95% confidence limits at each end point. The crude, complete‐case, and multiple imputation ORs (95% CIs) for a 25% or greater reduction in low‐density lipoprotein cholesterol were 3.5 (95% CI 3.1–3.9), 4.3 (95% CI 3.8–4.9), and 4.1 (95% CI 3.7–4.6), respectively. The crude, complete‐case, and multiple imputation ORs (95% CIs) for a 25% or greater reduction in non–high‐density lipoprotein cholesterol were 3.5 (95% CI 3.1–3.9), 4.5 (95% CI 4.0–5.2), and 4.4 (95% CI 3.9–4.9), respectively. The crude, complete‐case, and multiple imputation ORs (95% CIs) for 25% or greater reduction in TGs were 3.1 (95% CI 2.8–3.6), 4.0 (95% CI 3.5–4.6), and 4.1 (95% CI 3.6–4.6), respectively.ConclusionThe use of the multiple imputation method to account for missing data did not alter conclusions based on a complete‐case analysis. Given the frequency of missing data in research using electronic health records and pharmacy claims data, multiple imputation may play an important role in the validation of study findings.
Clinical Implications of Vancomycin Heteroresistant and Intermediately Susceptible Staphylococcus aureus
Authors: Gomes Diane M. , Ward Kristina E. , LaPlante Kerry L. 
Published: April 2015

Staphylococcus aureus (S. aureus) has proven to be a major pathogen with the emergence of methicillin‐resistant S. aureus (MRSA) infections and recently with heteroresistant vancomycin‐intermediate S. aureus (hVISA) and vancomycin‐intermediate S. aureus (VISA) infections. Although vancomycin is traditionally a first‐line and relatively effective antibiotic, its continued use is under question because reports of heteroresistance in S. aureus isolates are increasing. Both hVISA and VISA infections are associated with complicated clinical courses and treatment failures. The prevalence, mechanism of resistance, clinical significance, and laboratory detection of hVISA and VISA infections are not conclusive, making it difficult to apply research findings to clinical situations. We provide an evidence‐based review of S. aureus isolates expressing heterogenic and reduced susceptibility to vancomycin.