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Molecular assembly processes are generally driven by thermodynamic properties in solutions. Atomistic modeling can be very helpful in designing and understanding complex systems, except that bulk solvent is very inefficient to treat explicitly as discrete molecules. In this work, we develop and assess two multiscale solvation models for computing solvation thermodynamic properties. The new SLIC/CDC model combines continuum solvent electrostatics based on the solvent layer interface condition (SLIC) with new statistical thermodynamic models for hydrogen bonding and nonpolar modes: cavity formation, dispersion interactions, combinatorial mixing (CDC). Given the structures of 500 solutes, the SLIC/CDC model predicts Gibbs energies of solvation in water with an average accuracy better than 1 kcal/mol, when compared to experimental measurements, and better than 0.8 kcal/mol, when compared to explicit-solvent molecular dynamics simulations. The individual SLIC/CDC energy mode values agree quantitatively with those computed from explicit-solvent molecular dynamics. The previously published SLIC/SASA multiscale model combines the SLIC continuum electrostatic model with the solvent-accessible surface area (SASA) nonpolar energy mode. With our new, improved parametrization method, the SLIC/SASA model now predicts Gibbs energies of solvation with better than 1.4 kcal/mol average accuracy in aqueous systems, compared to experimental and explicit-solvent molecular dynamics, and better than 1.6 kcal/mol average accuracy in ionic liquids, compared to explicit-solvent molecular dynamics. Both models predict solvation entropies, and are the first implicit-solvation models capable of predicting solvation heat capacities.

Nanostructured heaters based on laser-induced graphene (LIG) are promising for heat generation and temperature control in a variety of applications due to their high efficiency as well as a fast, facile, and highly scalable fabrication process. While recent studies have shown that LIG can be written on a wide range of precursors, the reports on LIG-based heaters are mainly limited to polyimide film substrates. Here, we develop and characterize nanostructured heaters by direct writing of laser-induced graphene on nonuniform and structurally porous aramid woven fabric. The synthesis and writing of graphene on aramid fabric is conducted using a 10.6 μm CO2 laser. The quality of laser-induced graphene and electrical properties of the heater fabric is tuned by controlling the lasing process parameters. Produced heaters exhibit good electrothermal efficiency with steady-state temperatures up to 170 °C when subjected to an input power density of 1.5 W cm–2. In addition, the permeable texture of LIG–aramid fabric heaters allows for easy impregnation with thermosetting resins. We demonstrate the encapsulation of fabric heaters with two different types of thermosetting resins to develop both flexible and stiff composites. A flexible heater is produced by the impregnation of LIG–aramid fabric by silicone rubber. While the flexible composite heater exhibits inferior electrothermal performance compared to neat LIG–aramid fabric, it shows consistent electrothermal performance under various electrical and mechanical loading conditions. A multifunctional fiber-reinforced composite panel with integrated de-icing functionality is also manufactured using one ply of LIG–aramid fabric heater as part of the composite layup. The results of de-icing experiments show excellent de-icing capability, where a 5 mm thick piece of ice is completely melted away within 2 min using an input power of 12.8 W.

OBJECTIVES/HYPOTHESIS: To understand the effect of the COVID-19 pandemic on the volume, quality, and impact of otolaryngology publications. STUDY DESIGN: Retrospective analysis. METHODS: Fifteen of the top peer-reviewed otolaryngology journals were queried on PubMed for COVID and non-COVID-related articles from April 1, 2020 to March 31, 2021 (pandemic period) and pre-COVID articles from the year prior. Information on total number of submissions and rate of acceptance were collected from seven top-ranked journals. RESULTS: Our PubMed query returned 759 COVID articles, 4,885 non-COVID articles, and 4,200 pre-COVID articles, corresponding to a 34% increase in otolaryngology publications during the pandemic period. Meta-analysis/reviews and miscellaneous publication types made up a larger portion of COVID publications than that of non-COVID and pre-COVID publications. Compared to pre-COVID articles, citations per article 120 days after publication and Altmetric Attention Score were higher in both COVID articles (citations/article: 2.75 ± 0.45, P < .001; Altmetric Attention Score: 2.05 ± 0.60, P = .001) and non-COVID articles (citations/article: 0.03 ± 0.01, P = .002; Altmetric Attention Score: 0.67 ± 0.28, P = .016). COVID manuscripts were associated with a 1.65 times higher acceptance rate compared to non-COVID articles (P < .001). CONCLUSIONS: COVID-19 was associated with an increase in volume, citations, and attention for both COVID and non-COVID articles compared to pre-COVID articles. However, COVID articles were associated with lower evidence levels than non-COVID and pre-COVID articles. LEVEL OF EVIDENCE: Level 3 Laryngoscope, 2021.

From 1821 to 1829, Sir Charles Bell presented cases of facial paralysis from infection, trauma, and unknown causes. As such, "Bell's palsy" initially referred to facial palsy of any etiology. Today, the term is reserved for idiopathic peripheral facial palsy. The objectives of this analysis were to establish when the eponym came to vogue and delineate the semantic shift from its original definition to its current one.Extensive review of available 19th and 20th century literature mentioning "Bell's palsy" and "Bell's paralysis."Historical accounts have eponymously attached Bell's name to facial paralysis as early as the 1840s-Bell's palsy was first used to describe cases of facial palsy of any cause. In 1886, Gowers characterized Bell's palsy as a "neuritis usually within the Fallopian Canal," distinguishing it as a separate etiology. Over the next decades, the definition narrowed to peripheral facial paralysis from cold exposure or unknown causes. By the 1940s, its natural history was well described-an acute, unilateral, idiopathic, and usually self-limited peripheral facial palsy.The semantic change of a word over time can tell us a remarkable story of its history and origins. Absence of a discrete lesion, lack of proven treatment, and good prognosis without intervention distinguished Bell's palsy from other causes of facial paralysis. Over time, the definition has narrowed from a facial palsy of any cause to an idiopathic peripheral facial palsy. Recent evidence supporting Bell's palsy as a viral mononeuritis may have driven its recent semantic change toward this specific etiology.

This is the first comparative study of a chemically homologous series of linear and two-dimensional polyaramids at high temperatures. Detailed comparisons are made in the bulk and at free surface e...

OBJECTIVE To compare surgical characteristics and complications between well drilling (WD) and subperiosteal pocket techniques (SPT) for receiver/stimulator (R/S) fixation of cochlear implant (CI), and conduct cost-effectiveness analysis. STUDY DESIGN Retrospective clinical study, decision-analysis model. SETTING Tertiary referral center. PATIENTS Three-hundred and eighty-eight CI recipients with a minimum of 6-months follow-up. INTERVENTIONS CI surgery using either WD or SPT for R/S fixation. A decision-analysis model was designed using data from a systematic literature review. MAIN OUTCOME MEASURES Surgical operation time, rates of major and minor long-term complications were compared. Incremental cost-effectiveness was also estimated, comparing the two methods of fixation. RESULTS We compared 179 WD with 209 SPT. Surgery time was significantly shorter in SPT (148 versus 169 min, p = 0.001) and remained significant after adjustment for possible confounders. Higher rates of major complications requiring surgical intervention were found with SPT (10.5% versus 4.5%, p = 0.042), however, the difference was not significant after adjusting for follow-up time (47.8 versus 32.5 months for SPT, WD respectively; p

David McDonogh, born into chattel slavery in Louisiana in the early 1800s, accomplished the unfathomable by becoming the first Black otolaryngologist in the United States of America. With tireless determination and profound intellect, Dr McDonogh surmounted immeasurable adversity along his improbable journey to freedom and success as an eye, ear, nose, and throat doctor in New York. His doctorate in medicine was posthumously awarded to his great-great-granddaughter in 2018 by the Columbia University Vagelos College of Physicians and Surgeons. In this History of Otolaryngology piece, we share his extraordinary story.

Purpose: Otolaryngologists are uniquely situated to provide sexual and gender minority (SGM) care, including gender-affirmation (voice/communication, facial surgery) and HIV/AIDS-related conditions. Yet, no research has characterized otolaryngology residency program directors' attitudes toward SGM-related curricula, nor opportunities for supporting training in SGM-related care. Methods: An anonymous cross-sectional e-mail survey was disseminated to 116 otolaryngology residency program directors in July–September 2019. Information collected included current/future curriculum in and attitudes toward SGM care, and program demographics. Data were categorical and analysis utilized chi-square test. Results: The 65 complete responses (56% rate) were nationally representative. Overall, 17% of programs include no SGM-related education. Subjective importance of SGM training ranged from not important at all (3%) to absolutely essential (11%), with mode of average importance (47%); this varied significantly by program geographic setting and population, and program size. The mean percentage of curriculum dedicated to SGM care was 1.0% for didactics and 0.7% for clinical. Curricula include HIV/AIDS-related conditions (58%), facial gender-affirming procedures (50%), culturally informed care (42%), changes with gender-affirming hormones (voice/communication: 48%, facial: 22%), and cancer in SGM patients (42%). Frequently reported barriers were insufficient experienced faculty (52%) and time (42%). Program directors deemed visiting expert lectures (66%), small-group discussion (39%), and online modules (27%) the best ways to incorporate SGM education. Conclusions: More than 80% of otolaryngology residency curricula in a representative national survey include SGM-related education, which represents a limited portion of total curriculum. These results highlight the opportunity for expert lectures and discussion-based and online tool development to facilitate standardized SGM education in otolaryngology residencies.

This combined American Neurotology Society, American Otological Society, and American Academy of Otolaryngology - Head and Neck Surgery Foundation document aims to provide guidance during the coronavirus disease of 2019 (COVID-19) on 1) "priority" of care for otologic and neurotologic patients in the office and operating room, and 2) optimal utilization of personal protective equipment. Given the paucity of evidence to inform otologic and neurotologic best practices during COVID-19, the recommendations herein are based on relevant peer-reviewed articles, the Centers for Disease Control and Prevention COVID-19 guidelines, United States and international hospital policies, and expert opinion. The suggestions presented here are not meant to be definitive, and best practices will undoubtedly change with increasing knowledge and high-quality data related to COVID-19. Interpretation of this guidance document is dependent on local factors including prevalence of COVID-19 in the surgeons' local community. This is not intended to set a standard of care, and should not supersede the clinician's best judgement when managing specific clinical concerns and/or regional conditions.Access to otologic and neurotologic care during and after the COVID-19 pandemic is dependent upon adequate protection of physicians, audiologists, and ancillary support staff. Otolaryngologists and associated staff are at high risk for COVID-19 disease transmission based on close contact with mucosal surfaces of the upper aerodigestive tract during diagnostic evaluation and therapeutic procedures. While many otologic and neurotologic conditions are not imminently life threatening, they have a major impact on communication, daily functioning, and quality of life. In addition, progression of disease and delay in treatment can result in cranial nerve deficits, intracranial and life-threatening complications, and/or irreversible consequences. In this regard, many otologic and neurotologic conditions should rightfully be considered "urgent," and almost all require timely attention to permit optimal outcomes. It is reasonable to proceed with otologic and neurotologic clinic visits and operative cases based on input from expert opinion of otologic care providers, clinic/hospital administration, infection prevention and control specialists, and local and state public health leaders. Significant regional variations in COVID-19 prevalence exist; therefore, physicians working with local municipalities are best suited to make determinations on the appropriateness and timing of otologic and neurotologic care.

OBJECTIVE To review occupational ergonomic risks for the Otologist and Neurotologist. DATA SOURCES MEDLINE, OVID, PubMed, and Google Scholar. STUDY SELECTION A search was conducted to identify all studies in the English language that involve ergonomic-related risks for surgeons. RESULTS Occupational hazards, particularly musculoskeletal disorders (MSDs), are common in the surgical community in general and among Otolaryngologists in particular. Very few studies have been conducted assessing MSDs specific to Otologists and Neurotologists. However, extrapolating from other surgical professions with similar ergonomic postures in the operation room and office, one can infer that cervical and lumbar pain are related to prolonged static sitting and neck flexion when working with a microscope and begins early in training. Early institution of correct ergonomic training is feasible and may be effective. Improved ergonomic habits include upright sitting, avoidance of neck flexion, initiating short breaks, and the use of chairs with arm and back support. Future technologies incorporated into otologic surgery should have improved ergonomic design. CONCLUSIONS Otologists and Neurotologists are exposed to MSDs directly related to their work demands. Incorporating healthy ergonomics into surgical training as well adopting correct posture and the use equipment designed for back support may help mitigate the long-terms risks of MSD.

Objective Our objective was to compare outcomes in speech and quality of life in those undergoing cochlear implantation for single-sided deafness (SSD), with the aim to characterize the clinical impact of underlying diagnosis in the affected ear and pre-operative hearing status. Study design Prospective case series. Setting Academic Cochlear Implant Center. Patients 42 adult patients implanted with the diagnosis of SSD. Interventions Patients were evaluated at 3-, 6-, and 12-months post-operatively using AZBio sentence and speech, and consonant-nucleus-consonant (CNC) depending on appropriate testing level. Our previously validated Comprehensive Cochlear Implant Quality of Life (CCIQ) questionnaire was administered. Main outcome measures Speech perception, quality of life. Results Subjects were stratified by the underlying diagnosis: Meniere's Disease (MD; n = 10), sudden sensorineural hearing loss (SSNHL; n = 13), and Other (eg TBI, acoustic neuroma, progressive, noise-induced; n = 19). Mean preoperative PTA of the implanted ear was 82dB ± 17; that of the nonimplanted ear was 32dB ± 17. SSNHL and MD demonstrated the highest speech perception score at 3 months (93 and 95%), and "Other" demonstrated the lowest scores at 88%. All 3 groups demonstrated nadir in speech scores at 6 months before improving at 12 months, but the "Other" diagnoses maintained the lowest speech testing across all time points. All 3 groups reported improved quality of life on CCIQ. Conclusions Subjects with SSNHL and MD demonstrate excellent speech perception and quality of life outcomes after cochlear implantation for SSD. Subjects with "Other" diagnoses underlying their SSD demonstrated lower scores on speech testing but nonetheless reported improved quality of life.

OBJECTIVES/HYPOTHESIS Evaluate technical success, tolerability, and safety of lidocaine iontophoresis and tympanostomy tube placement for children in an office setting. STUDY DESIGN Prospective individual cohort study. METHODS This prospective multicenter study evaluated in-office tube placement in children ages 6 months through 12 years of age. Anesthesia was achieved via lidocaine/epinephrine iontophoresis. Tube placement was conducted using an integrated and automated myringotomy and tube delivery system. Anxiolytics, sedation, and papoose board were not used. Technical success and safety were evaluated. Patients 5 to 12 years old self-reported tube placement pain using the Faces Pain Scale-Revised (FPS-R) instrument, which ranges from 0 (no pain) to 10 (very much pain). RESULTS Children were enrolled into three cohorts with 68, 47, and 222 children in the Operating Room (OR) Lead-In, Office Lead-In, and Pivotal cohorts, respectively. In the Pivotal cohort, there were 120 and 102 children in the

Interactions between a flexible beam and a fluid in a channel are of great relevance to biological hairy surfaces, aquatic vegetation, marine life (e.g., fish gills), and many industrial systems alike. While steady state response of a beam to such flows is fairly well-explored, their behavior in the transient regime is not fully understood. A series of numerical simulations are performed to study the laminar Couette flow of an incompressible viscous fluid past an elastic beam in a two-dimensional channel. The flexible beam is perpendicular to the direction of flow, and its base is fixed to the stationary bottom of the channel. We measure the evolution of the Vogel exponent, drag reduction, and reconfiguration number during the transient and steady-state response of the fluid–structure system for different geometrical and physical properties. Our benchmark shows a good agreement between numerical and experimental observations. Our results show that the system's steady-state response at different bulk-fluid velocities can be reproduced by investigating the shear flow response during the transient regime. We define a new variable that characterizes the evolution of the local velocity profile in the proximity of the free end of the beam and use that to characterize the transient-regime response. The analysis yields insight into the competing effects of elasticity of the beam and non-linear flow response.

We highlight the most recent developments of the solvation-layer interface condition (SLIC) continuum dielectric model in predicting solvation thermodynamics of neutral small molecules in water and multiple ionic liquids. We demonstrate that a simple temperature-dependent solvent-accessible-surface-area (SASA) correlation and a cavity-dispersion-combinatorial (CDC) theory, combined with the SLIC electrostatics model, provide highly accurate predictions of Gibbs solvation energies, solvation entropies, and solvation heat capacities. The SLIC/SASA model parameters are temperature dependent, whereas the SLIC/CDC parameters are constant. To address the lack of experimental data pertaining to the accuracy of the models, we conducted an extensive literature search and data compilation to obtain credible experimental solvation data. This yielded 159 and 123 data points for hydration entropies and heat capacities of neutral small molecules, respectively. Compared to experimental data, the SLIC/SASA and SLIC/CDC models, respectively, achieve an RMS error 1.39 (1.24) and 1.15 (1.76) kcal/mol for hydration free energy (hydration entropy) predictions. Solvation heat capacities are predicted with RMS errors 24.42 and 46.17 cal/mol/K. Most remarkably, the SLIC/CDC predictions of solvation entropies and heat capacities are made without apriori knowledge of experimental solvation entropies. In addition, the SLIC/SASA predictions of Gibbs solvation energies (solvation entropies) of 12 amino acid side-chain analogs in seven (three) ionic liquids are compared to the available explicit-solvent simulation data from Paluch et al.~\cite{Paluch12} and Latif~\cite{Latif14} et al.

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Significance In humans, inner ear development is completed in utero, with hearing onset at ∼20 weeks of gestation. However, genetic forms of congenital deafness are typically diagnosed during the neonatal period. Gene therapy approaches in animal models should therefore be tested after the period of hearing onset, to determine whether they can reverse an existing deafness phenotype. Here, we used a mouse model of DFNB9, a human deafness form accounting for 2–8% of all cases of congenital genetic deafness. We show that local gene therapy in the mutant mice not only prevents deafness when administered to immature hearing organs, but also durably restores hearing when administered at a mature stage, raising hopes for future gene therapy trials in DFNB9 patients., Autosomal recessive genetic forms (DFNB) account for most cases of profound congenital deafness. Adeno-associated virus (AAV)-based gene therapy is a promising therapeutic option, but is limited by a potentially short therapeutic window and the constrained packaging capacity of the vector. We focus here on the otoferlin gene underlying DFNB9, one of the most frequent genetic forms of congenital deafness. We adopted a dual AAV approach using two different recombinant vectors, one containing the 5′ and the other the 3′ portions of otoferlin cDNA, which exceed the packaging capacity of the AAV when combined. A single delivery of the vector pair into the mature cochlea of Otof−/− mutant mice reconstituted the otoferlin cDNA coding sequence through recombination of the 5′ and 3′ cDNAs, leading to the durable restoration of otoferlin expression in transduced cells and a reversal of the deafness phenotype, raising hopes for future gene therapy trials in DFNB9 patients.

Real-space methods of characterizing high-performance fibers’ inherent morphologies will greatly enhance our understanding of the key structural features within fibers and their impacts on mechanical performance. Here, we report on structure–property correlations of two new classes of commercial DuPont Kevlar fibers, termed “K29 sample test” and “K49 sample test,” as well as conventional K29 and K49 fibers.* Through multifrequency atomic force microscope scans of internal fiber surfaces prepared by a focused ion beam notch technique, we directly capture nano- and microstructural features that define the inherent structures of these fibers. Integrating these findings with X-ray scattering experiments, we relate crystallographic and real-space measurements to each other, highlighting how multiscale structural motifs manifest within fibers. By carrying out tensile tests on single fibers drawn from the same tows, we also glean new insights into the structure–property relationships that dictate the mechanical behavior of these fibers.

Hearing loss is a significant public health concern, affecting over 250 million people worldwide. Both genetic and environmental etiologies are linked to hearing loss, but in many cases the underlying cellular pathophysiology is not well understood, highlighting the importance of further discovery. We found that inactivation of the gene Tmtc4 (transmembrane and tetratricopeptide repeat 4), which was broadly expressed in the mouse cochlea, caused acquired hearing loss in mice. Our data showed Tmtc4 enriched in the endoplasmic reticulum, and that it functioned by regulating Ca2+ dynamics and the unfolded protein response (UPR). Given this genetic linkage of the UPR to hearing loss, we demonstrated a direct link between the more common noise-induced hearing loss (NIHL) and the UPR. These experiments suggested a novel approach to treatment. We demonstrated that the small-molecule UPR and stress response modulator ISRIB (integrated stress response inhibitor), which activates eIF2B, prevented NIHL in a mouse model. Moreover, in an inverse genetic complementation approach, we demonstrated that mice with homozygous inactivation of both Tmtc4 and Chop had less hearing loss than knockout of Tmtc4 alone. This study implicated a novel mechanism for hearing impairment, highlighting a potential treatment approach for a broad range of human hearing loss disorders.

OBJECTIVE Otic drops are one of the most frequently prescribed medications in otolaryngology. However, some forms of these drops can be very expensive, and ophthalmic formulations are sometimes used by practitioners to decrease the cost for their patients. The goal of this study is to determine the cost differential between otic and ophthalmic drops. METHODS Pharmacies in New York City, Chicago, and Portland were surveyed in the span of 6 weeks by telephone to evaluate the current prices of various otic and ophthalmic drops commonly prescribed by otolaryngologists. RESULTS A total of 83 pharmacies were surveyed. Surveyed drugs included ciprofloxacin/dexamethasone (cip/dex) otic, neomycin/polymyxin B sulfates/hydrocortisone (neo/poly/HC) otic, acetic acid (AA) otic, acetic acid/hydrocortisone (AA/HC) otic, ofloxacin otic, ofloxacin ophthalmic, and tobramycin/dexamethasone (tob/dex) ophthalmic. Per milliliter, cip/dex otic was consistently the most expensive, with a median price of $38.00 per milliliter. Among the antibiotic drops, neo/poly/HC otic was the least expensive formulation with a median price of $11.60 per milliliter. Ofloxacin ophthalmic was significantly less expensive than the otic formulation, at $11.00 and $31.00 per milliliter, respectively (adjusted p

Aspen Plus® simulations using the Peng-Robinson (PR-EOS) and the COSMO-SAC models were performed to study absorption power cycles (APCs) using mixtures of R-134a with two ionic liquids, [C2C1im][Tf2N] or [C6C1im][Tf2N], and compared against an R-134a organic Rankine cycle (ORC) operating under similar conditions. The PR-EOS results were in agreement with calculations from a PR model fitted to the R-134a+IL experimental phase equilibrium data. The APCs have similar efficiencies and outperform the ORC by 3-46%, with the largest differences observed when operating with lower grade (lower TH) heating sources, lower quality cooling (higher TL) and lower subcooling in the pump inlet stream. The PR-EOS and the COSMO-SAC results follow similar trends, but numerical discrepancies are observed in the cycle efficiencies and stream flow rates and compositions due to differences in solubilities and enthalpy changes between both models, suggesting that improvements are needed to increase the accuracy of COSMO-SAC for these systems.

The processing conditions used in the production of advanced polymer fibers facilitate the formation of an oriented fibrillar network that consists of structures spanning multiple length scales. The irregular nature of fiber tensile fracture surfaces suggests that their structural integrity is defined by the degree of lateral (interfacial) interactions that exist within the fiber microstructure. To date, experimental studies have quantified interfacial adhesion between nanoscale fibrils measuring 10-50 nm in width, and the global fracture energy through applying peel loads to fiber halves. However, a more in-depth evaluation of tensile fracture indicates that fiber failure typically occurs at an intermediate length scale, involving fibrillation along interfaces between fibril bundles of a few 100s of nanometers in width. Interaction mechanisms at this length scale have not yet been studied, due in part to a lack of established experimental techniques. Here, a new focused ion beam-based sample preparation protocol is combined with nanoindentation to probe interfaces at the intermediate length scale in two high-performance fibers, a rigid-rod poly(

Layered systems of commonly available fabric materials can be used by the public and healthcare providers in face masks to reduce the risk of inhaling viruses with protection that is about equivalent to or better than the filtration and adsorption offered by 5-layer N95 respirators. Over 70 different common fabric combinations and masks were evaluated under steady-state, forced convection air flux with pulsed aerosols that simulate forceful respiration. The aerosols contain fluorescent virus-like nanoparticles to track transmission through materials that greatly assist the accuracy of detection, thus avoiding artifacts including pore flooding and the loss of aerosol due to evaporation and droplet breakup. Effective materials comprise both absorbent, hydrophilic layers and barrier, hydrophobic layers. Although the hydrophobic layers can adhere virus-like nanoparticles, they may also repel droplets from adjacent absorbent layers and prevent wicking transport across the fabric system. Effective designs are noted with absorbent layers comprising terry cloth towel, quilting cotton, and flannel. Effective designs are noted with barrier layers comprising nonwoven polypropylene, polyester, and polyaramid.

This article is an overview of the care of patients requiring revision surgery for otosclerosis. Preoperative evaluation of the patient including surgical history, audiologic results, and physical findings is discussed, and the causes of failure of primary surgery are reviewed. A discussion of evidence-based surgical technique and postoperative care then follows.

Linear elastic fracture modeling coupled with empirical material tensile data result in good quantitative agreement with the experimental determination of mode I fracture for both brittle and toughened epoxy nanocomposites. The nanocomposites are comprised of diglycidyl ether of bisphenol A cured with Jeffamine D-230 and some were filled with core-shell rubber nanoparticles of varying concentrations. The quasi-static single-edge notched bending (SENB) test is modeled using both the surface-based cohesive zone (CZS) and extended finite element methods (XFEM) implemented in the Abaqus software. For each material considered, the critical load predicted by the simulated SENB test is used to calculate the mode I fracture toughness. Damage initiates in these models when nodes at the simulated crack tip attain the experimentally measured yield stress. Prediction of fracture processes using a generalized truncated linear traction–separation law (TSL) was significantly improved by considering the case of a linear softening function. There are no adjustable parameters in the XFEM model. The CZS model requires only optimization of the element displacement at the fracture parameter. Thus, these continuum methods describe these materials in mode I fracture with a minimum number of independent parameters.

Objective The prevalence of unilateral hearing loss (UHL) in adults has not been well characterized. The objectives of this study are to determine the prevalence of UHL in U.S. adults and its treatment with hearing aids using a nationally representative study. Study design Cross-sectional national epidemiologic study (n = 6,242). Methods Subjects ≥ 18 years old with audiometric testing in the 2005 to 2006, 2009 to 2010, and 2011 to 2012 cycles of the National Health and Nutrition Examination Study were included. UHL was defined as normal hearing (≤25 decibels hearing level [dB HL] pure tone average [PTA]) in one ear and at least mild hearing loss (>25 dB HL PTA) in the other ear. Hearing aid usage was defined by at least 5 hours per week (2005-2006) or at least seldom (2009-2012) use. Sampling weights were utilized to ensure generalizability to the U.S. Results The overall prevalence of UHL in adult Americans was 7.2% (95% confidence interval 6.1%-8.6%), with 5.7% (4.8%-6.7%) having mild and 1.5% (0.1%-2.1%) with moderate-or-worse UHL; nearly one-third of the latter reported trouble hearing. The prevalence of hearing aid usage in those with UHL was 2.0% (0.6%-6.7%). Of those with mild UHL, 1.4% (0.2%-8.0%) used hearing aids. Of those with moderate UHL, 4.2% (0.1%-22%) used hearing aids. Among those with UHL and also at least moderate subjective difficulty hearing, only 11% wore hearing aids. Conclusion UHL is common among U.S. adults. Hearing aid usage is very low, even when there is perceived handicap. Public health education is needed to increase awareness of and auditory rehabilitation for UHL. Level of evidence 2. Laryngoscope, 128:1681-1686, 2018.

Advancements in processing techniques have facilitated the development of a series of unique high-performance DuPont™ Kevlar® fibers. Directly characterizing interior structures of these fibers is vital for connecting processing variations with resulting mechanical properties. Here we report detailed investigations of processing-internal structure-property relationships among four distinct classes of Kevlar® fibers (K119, K29, KM2+, and K49). We employ a novel focused ion beam (FIB) notch technique to obtain pristine interior fiber planes and measure morphology and transverse stiffness across these surfaces via multifrequency atomic force microscopy (AFM) maps. Combining these observations with tensile tests of single fibers drawn from the same tows, we acquire remarkable insights into structural motifs that strongly correlate with measured mechanical properties. Most notably, we uncover alternating stiffness bands that are especially apparent in low-modulus, non-heat-treated fibers, revealing a unique manifestation of internal structural variations that helps explain the observed trends in material response.

A prospective study to evaluate short-term changes in occlusal force and contact surface area associated with retainer wear. Total 32 subjects, randomly assigned to two experimental groups, a clear overlay group and a wrap-around retainer group, were followed to assess occlusal changes. Assessments were made utilizing the T-Scan II (Tekscan, Inc., 307 West First St., South Boston, MA 02127) method of occlusal analysis at 3 time periods; T0, at debond all subjects received lower fixed canine to canine retainer and upper clear overlay retainers; T1, 2 weeks later 14 subjects received wrap-around retainers and the clear overlay retainer group was checked (18 subjects); T2, occlusal contact assessment 2 months later for both groups. During T0–T1, the occlusion with clear overlay retainers showed a significant decrease in posterior surface area contact (p 0.05). An independent sample (15 subjects) showed high intraclass correlations (r > 0.90) between replicate measurements of relative force, indicating low technical errors when multiple measurements are used. In conclusion, there were no significant net changes in occlusal forces or areas after 6 weeks of comparison between the wrap-around and clear overlay retainers following orthodontic therapy. In addition, it was shown that the T-Scan is a reliable apparatus for analysis of relative force.