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Current technologies for the manufacture of fiber-reinforced polymer composites are energy-intensive, environmentally unfriendly, and time-consuming and require expensive equipment and resources. In addition, composites typically lack key nonstructural functionalities (e.g., electrical conductivity for deicing, lightning strike protection, and structural health monitoring), which are crucial to many applications such as aerospace and wind energy. Here, we present a new approach for rapid and energy-efficient manufacturing of multifunctional composites without using traditional expensive autoclaves, ovens, or heated molds used for curing of composites. Our approach is predicated on embedding a thin conductive nanostructured paper in the composite layup to act as a resistive heater for triggering frontal polymerization of the matrix thermosetting resin of the composite laminate. Upon passing electric current, the nanostructured paper quickly heats up and initiates frontal polymerization, which then rapidly propagates through the thickness of the laminate, resulting in rapid curing of composites (within seconds to few minutes) irrespective of the size of the composite laminate. The integrated nanostructured paper remains advantageous during the service of the composite part by imparting new functionalities (e.g., deicing) to the cured composite, owing to its excellent electrical conductivity and electrothermal properties. In this work, we first study the influence of several composite processing parameters on the electrothermal properties of the nanostructured paper and determine the power required for rapid initiation of frontal polymerization. We then successfully fabricate a 10 cm × 10 cm composite panel within 1 min using only 4.49 kJ of energy, which is 4 orders of magnitude less than the energy consumed by the traditional bulk, oven-curing technique. Detailed experiments are conducted to provide an in-depth understanding of the effect of heater position, tooling material, and input power on frontal curing of composite laminates. The multifunctional response of produced composites is demonstrated by performing a deicing experiment, where a 50 × 50 × 3 mm

Nanocomposite film heaters are promising for out-of-oven (OoO) and energy-efficient curing of fiber-reinforced polymer composites. However, the current techniques for manufacturing nanocomposite film heaters are intensive in terms of time and energy and require expensive resources. In this work, we present a facile and rapid approach for preparation of nanocomposite film heaters with excellent heat generation properties based on a frontally polymerizable resin system. This approach enables rapid fabrication of nanocomposite films within a few minutes and without the need for using expensive equipment, making it suitable for mass production of nanocomposite film heaters. Various characterization techniques are used to determine the morphology, composition, and mechanical properties of nanocomposite films. The electrothermal performance of nanocomposite film heaters are then evaluated under various conditions. Nanostructured heaters exhibit excellent Joule heating properties, where temperatures as high as ∼132°C can be reached within only 2 min using a low input power density of ∼2 W cm−2. Finally, a nanocomposite film heater is used for OoO curing of a small composite panel with minimal energy consumption. Using this approach, 0.1 MJ of energy is consumed during the 4-h cure cycle of a commercial prepreg system, which would otherwise require at least 40.5 MJ of energy to cure using a convection oven.

The aim of this work is to improve the thermal insulation performance (the time needed for the sample’s top surface to reach 140 °C) of carbon aerogels (CAs) using phase change materials (PCMs). CAs were prepared through the carbonization of organic aerogels, synthesized by the sol-gel polymerization of a novolac solution under a solvent-saturated atmosphere. Field emission scanning electron microscopy (FE-SEM), N 2 adsorption and time-temperature history behavior (insulation performance) characterization methods were used to investigate the morphology, microstructural and thermal properties of fabricated CAs, respectively. The CA sample prepared from the initial sol containing 20 wt.% of novolac resin was identified as the proper CA sample to be the matrix for MgCl 2 ·6H 2 O-filled samples. The CAs were impregnated by MgCl 2 ·6H 2 O using the immersion process. The influence of PCM content on the heat transfer of PCM-filled CAs was also investigated. Results presented here revealed that the amounts of filled PCMs can play an important role in improving the thermal performance of samples, in a specific temperature range (specifically around the melting point of PCM). Moreover, it was found that the low thermal conductivity of CA, combined with the high heat capacity of PCM, increased the time required to reach the top surface temperature of sample (140 °C). Increasing PCM contents enhanced the heat absorption capacity of the samples. In addition, the higher PCM contents resulted in the longer time interval of latent heat absorption. Furthermore, inhomogeneous impregnation of PCM in the structure of carbon aerogels resulted in more efficient structures, as, in this way, PCM can be located in the right place to meet required heat for phase change.

New carbon aerogels were prepared using Novolac sol as precursor. The elaboration process and the structural characterizations of these porous carbon materials are described in the present study. Series of monolithic carbon aerogels were prepared in 2-propanol by crosslinking Novolac with hexamethylene tetra amine catalyst via sol–gel polymerization in the solvent vapor-saturated atmosphere followed by pyrolysis. Low density materials (from 0.3 to 0.6 g/cm3) were obtained after pyrolysis. These newly carbon aerogels were characterized using mercury porosimetry, nitrogen adsorption and scanning electron microscopy. All prepared materials have shown a nanostructured solid network (specific surface areas between 554 and 635 m2/g) and all samples have pore volumes as large as 0.97 cm3/g. Influence of Novolac concentration in the initial sol on the carbon aerogel structure was investigated. A special attention was dedicated to the different microstructures and morphologies occurring after the elaboration process. In particular, changing solid network from colloidal to polymeric network was studied in terms of micro, meso and macro porosity. In parallel, mechanical properties were presented in terms of bulk modulus.

Three sets of novolac xerogel prepared with various solvents and the effect of solvent on drying shrinkage investigated. The results show that the polarity of solvent has profound effect on microstructure of gel. As the polarity of solvent increases, the ultimate particle size and pore size decrease and consequently, the higher capillary pressure exerts on gel and hence, more shrinkage observed.

BACKGROUND The endoscopic endonasal approach (EEA) has developed as an emerging surgical corridor to the craniovertebral junction (CVJ). In addition to understanding its indications and surgical anatomy, the ability to predict its inferior limit is vital for optimal surgical planning. OBJECTIVE To develop a method that accurately predicts the inferior limit of the EEA on the CVJ radiologically and to compare this with other currently used methods. METHODS Predissection computerized tomographic scans of 9 cadaver heads were used to delineate a novel line, the naso-axial line (NAxL), to predict the inferior EEA limit on the upper cervical spine. A previously described method with the use of the nasopalatine line (NPL or Kassam line) was also used. On computerized tomographic scans obtained following dissection of the EEA, the predicted inferior limits were compared with the actual extent of dissection. RESULTS The postdissection inferior EEA limit ranged from the dens tip to the upper half of the C2 body, which matched the limit predicted by NAxL, with no statistically significant difference between them. In contrast to the NAxL, the NPL predicted a significantly lower EEA limit (P < .001), ranging from the lower half of the C2 body to the superior end plate of C3. CONCLUSION The novel NAxL more accurately predicts the inferior limit of the EEA than the NPL. This method, which can be easily used on preoperative sagittal scans, accounts for variations in patients' anatomy and can aid surgeons in the assessment of the EEA to address caudal CVJ pathology.

Objectives/Hypothesis: To analyze the microbiological origins of deep neck space infections requiring surgical intervention in a pediatric population. Study Design: Retrospective cohort study. Methods: The study population (N = 136) included all pediatric patients surgically treated for deep neck space abscesses in a metropolitan tertiary care children's hospital over the course of 5 years (September 2004–August 2009). Demographic and clinical information was compared with microbiological isolate data. Results: Microbiological analysis of 118 bacterial isolates demonstrated 49 (42%) methicillin-resistant Staphylococcus aureus (MRSA), 35 (30%) methicillin-sensitive S. aureus, and 34 (28%) non-S. aureus (N-SA) isolates. The median age was 16 months (range, 1 month–13years). Patients

To determine if degree of lingual tonsil hypertrophy (LTH) correlates with pharyngeal reflux.Prospective.Patients with flexible laryngoscopic evidence of LTH were included. Degree of LTH was graded mild, moderate, or severe by two otolaryngologists blinded to pH study results. Three-sensor pH study results were correlated to LTH grade.Nineteen patients were included (five with mild LTH, eight with moderate LTH, and six with severe LTH). Nasopharyngeal reflux (NPR) eventspH4 were found in four of six severe LTH patients but no mild or moderate LTH patients (P = 0.006). All severe LTH patients had NPR eventspH5, compared with only 4 of 11 mild or moderate LTH patients (P = 0.017). At the UES, 4 of 6 severe LTH patients had pathologic reflux, compared with 4 of 13 mild or moderate (P = 0.025). Interobserver reliability calculated by Cohen's kappa was excellent (0.92).Our study shows a continuum of increasing pharyngeal reflux with higher LTH severity. Severe LTH may be a reliable physical sign of pharyngeal reflux, especially NPR.

Objectives:Analyze the frequency of and techniques used in performing tracheostomies. Understand the prevailing contraindications used in the decision between open versus percutaneous method. Evaluate outcomes among the 2 modes of tracheostomy procedures.Methods:Case-series review of all patients who underwent a tracheostomy spanning 4 years within a tertiary metropolitan hospital. Clinical and demographic data were used to compare the 2 groups of patients with respect to average age, hospital stay, related emergency department (ED) visits, and other complications.Results:A total of 1333 tracheostomies were performed on 1302 patients. This included 452 (34%) open versus 881 (66%) via the percutaneous dilatational technique (PDT). There was no difference in short-term complications between the 2 groups. The primary long-term complication, tracheal stenosis, occurred most commonly in the PDT group. The contraindications practiced in decision for open versus PDT are not uniform among the various services per...

Objectives:(1) Assess the effectiveness of multilevel surgery in the treatment of obstructive sleep apnea (OSA). (2) Analyze outcomes based on reduction of apnea hypopnea index (AHI) and positive airway treatment pressures.Methods:Case-series review in a tertiary referral center. A total of 44 patients underwent multilevel OSA surgery between November 2009 and September 2013. Depending on the preoperative examination and OSA severity based on sleep study, patients underwent multilevel surgery including nasal, oropharyngeal, transoral robotic, tongue base, hyoid, and/or orthognathic surgery. Follow-up sleep studies at 4 months were obtained and compared with preoperative data.Results:Overall AHI was significantly reduced from a mean of 44.5 to 19.9 (P = .0008), 78.9 to 35.8 (P = .0001) in the severe OSA group, 21.4 to 7.0 (P = .0001) in the moderate group, and 8.7 to 4.5 (P = .0004) in the mild group. AHI reduced from mean of 98.1 to 31.7 (P = .0013) in those who underwent orthognathic surgery and 36.1 to ...

Objectives:A majority of anterior skull base meningoceles are often managed via the endoscopic endonasal approach (EEA) for the excision and repair of the cerebrospinal fluid (CSF) leak, in addition to the reconstruction of the skull base defect. The aim of the study was evaluation of an institutional case series to identify specific risks and strategies for successful management of anterior skull base meningoceles.Methods:Case series review of all surgical cases involving repair of any anterior skull base meningocele spanning 3 years.Results:A total of 18 patients were managed surgically for repair of meningocele with or without CSF rhinorrhea. All patients had postoperative follow-up to one year. EEA was used in 17 patients, and one had a combined transcranial with endoscopic approach. Four patients had meningoceles with a larger than 1.0-cm bony skull base defect. Large spontaneous meningoceles along the ethmoid were likely to include cerebrovascular structures within their intranasal component. Nasal ...

We conducted a prospective analysis to independently observe the initial opinion of: (1) consulting pediatric residents (postgraduate year 2 [PGY-2]), (2) corresponding considting attending physicians (general pediatric or pediatric emergency medicine) physician, and (3) consulting otolaryngology PGY-2 residents when assessing patients for “noisy breathing.” Each was asked to define the type of noisy breathing present and to formulate a diagnosis based on a limited set of choices. The final diagnosis was determined by a single attending pediatric otolaryngologist (S.E.S.) at the completion of the diagnostic workup. The accuracy for characterization of breath sounds for the pediatric residents, attending pediatricians, and otolaryngology residents were 26.1%, 23.5%, and 98.6%, respectively. The positive predictive values for the determination of diagnosis were 71.6%, 69.4%, and 76.6%, respectively. These findings indicate that pediatric residents and attending pediatricians may be deficient in their ability to characterize the breath sounds commonly seen inpatients with noisy breathing. Further education of pediatricians may lead to a more accurate diagnostic evaluation of a child with noisy breathing.

Summary Orbital complications of sinusitis (OCS) are uncommon in children and are extremely rare in the neonatal period with only one review published in the literature. Reported surgical techniques to manage orbital abscess collection involve either an external ethmoidectomy or transconjunctival approach for decompression and drainage. We report the case of a 13 day-old male who was managed with endoscopic drainage of a methicillin-resistant Staphylococcus aureus (MRSA) orbital abscess.

Objective: 1) Identify acute and chronic indications for orbital and/or optic nerve decompression. 2) Review known techniques for endoscopic orbital decompression. 3) Evaluate the necessity to include inferior orbital wall/orbital floor. 4) Compare and contrast the endoscopic technique in comparison to various open methods.Method: Retrospective review of all patients that underwent endoscopic orbital decompression procedures between 2009 and 2011. Data analysis included review of perioperative clinical findings, operative technical details, radiology data, and outcomes.Results: A total of 15 orbital decompressions were performed. All patients underwent endoscopic medial orbital wall decompression, 2 included the orbital floor. The majority of the patients had allergic fungal sinusitis as their primary diagnosis for surgical indication (n = 7, 47%). Neoplasms (n = 5, 33%) and Graves disease (n = 3, 20%) were the remaining diagnoses. Restricted ocular motility, proptosis, and diplopia were the most common p...

Objective: 1) Evaluate the indications for performing a tracheostomy across the spectrum of all trauma and pulmonary critical care patients. 2) Understand the existing contraindications used in the decision against performing a percutaneous dilatational tracheostomy. 3) Examine outcomes among the 2 modes of tracheotomy procedures.Method: A retrospective review identifying all patients who underwent open surgical or percutaneous dilatational tracheostomy procedure spanning 3 years (from 2008) within a tertiary hospital. Clinical and demographic data were used to compare the 2 groups of patients with respect to average age, hospital stay, related ER visits, and other complications.Results: A total of 1333 tracheostomies were performed on 1302 patients. This included 452 (34%) open surgical versus 881 (66%) percutaneous dilatational techniques. There was no significant difference in age between the 2 groups (53 years). The average length of hospital stay was 21 days, indifferent among the 2 groups. The major...

Decisions are made on the fundamental sinus approaches for endonasal access to the skull base and the technical adjuncts that are necessary to optimize the procedure. These include discussions on pati

To analyze the microbiological origins of deep neck space infections requiring surgical intervention in a pediatric population.Retrospective cohort study.The study population (N = 136) included all pediatric patients surgically treated for deep neck space abscesses in a metropolitan tertiary care children's hospital over the course of 5 years (September 2004-August 2009). Demographic and clinical information was compared with microbiological isolate data.Microbiological analysis of 118 bacterial isolates demonstrated 49 (42%) methicillin-resistant Staphylococcus aureus (MRSA), 35 (30%) methicillin-sensitive S. aureus, and 34 (28%) non-S. aureus (N-SA) isolates. The median age was 16 months (range, 1 month-13years). Patients16 months of age were 10 times more likely to have an S. aureus (SA) infection versus N-SA (P.0001). MRSA comprised the majority of all SA isolates (58%). Eighty percent of all SA abscesses were located in the lateral neck. African American pediatric patients accounted for 70% of all deep neck space infections, and 86% of all MRSA infections. Clindamycin resistance was noted in 8% (4/49) of all community-acquired MRSA isolates.Children younger than 16 months and/or with lateral neck abscesses are at a significantly increased risk of having an SA infection, the majority being MRSA.

We conducted a prospective analysis to independently observe the initial opinion of: (1) consulting pediatric residents (postgraduate year 2 [PGY-2]), (2) corresponding consulting attending physicians (general pediatric or pediatric emergency medicine), and (3) consulting otolaryngology PGY-2 residents when assessing patients for "noisy breathing." Each was asked to define the type of noisy breathing present and to formulate a diagnosis based on a limited set of choices. The final diagnosis was determined by a single attending pediatric otolaryngologist (S.E.S.) at the completion of the diagnostic workup. The accuracy for characterization of breath sounds for the pediatric residents, attending pediatricians, and otolaryngology residents were 26.1%, 23.5%, and 98.6%, respectively. The positive predictive values for the determination of diagnosis were 71.6%, 69.4%, and 76.6%, respectively. These findings indicate that pediatric residents and attending pediatricians may be deficient in their ability to characterize the breath sounds commonly seen in patients with noisy breathing. Further education of pediatricians may lead to a more accurate diagnostic evaluation of a child with noisy breathing.

Although dysphonia is a common complaint among patients seen in an otolaryngology clinic, an autoimmune cause of the problem is less common. Autoimmune disease can be the source of various laryngologic manifestations, but diagnosis depends on a high index of suspicion, careful patient evaluation and testing, and videolaryngoscopy (videostroboscopy if available) to uncover specific identifying findings. This report describes a patient presenting with upper-range vocal difficulties who was found to have early systemic lupus erythematosus.

Objective To determine the sensitivity and specificity of airway fluoroscopy in the diagnosis of pediatric laryngotracheal abnormalities. Design Retrospective chart review. Setting Tertiary care children's hospital. Patients Thirty-nine children, with a mean age of 18 months at the time of evaluation, were evaluated for stridor. Main Outcome Measures Diagnoses made by airway fluoroscopy and endoscopy. The medical records of patients who had undergone both airway fluoroscopy and airway endoscopy for the evaluation of stridor over a 5-year period were reviewed. The sensitivity, specificity, and positive and negative predictive values of airway fluoroscopy in the diagnosis of laryngomalacia, tracheomalacia, airway stenosis at any level, and airway mass lesions were determined using endoscopic evaluation as the “gold standard.” Results Twenty-three of 39 patients (59%) received a different diagnosis by airway endoscopy than by airway fluoroscopy. The sensitivity of airway fluoroscopy in the diagnosis of laryngomalacia, tracheomalacia, airway stenosis, and an airway mass was 27%, 20%, 69%, and 43%, respectively. The specificity for the same diagnoses was 100%, 94%, 100%, and 100%, respectively. Conclusions Airway fluoroscopy appears to be reliable in the diagnosis of laryngomalacia, tracheomalacia, airway stenosis, and airway masses because of its high specificity. However, its sensitivity in detecting these common causes of stridor is poor. Negative fluoroscopic study results require further diagnostic evaluation if the clinical indication exists; therefore, the value of fluoroscopy as a screening tool remains uncertain.

Objectives To evaluate the epidemiologic manifestations of pediatric Staphylococcus aureus head and neck infections nationwide and to identify possible trends in the antibiotic drug susceptibility of S aureus during a 6-year period. Design Retrospective review of microbiologic data from a peer-reviewed national database. Setting More than 300 hospitals nationwide. Patients All pediatric patients with head and neck infections involving S aureus . Main Outcome Measures Anatomic sites were divided into oropharynx/neck, sinonasal, and otologic infection categories. Demographic and antimicrobial drug susceptibility patterns were reviewed. Results A total of 21 009 pediatric head and neck S aureus infections that occurred between January 2001 and December 31, 2006 were gathered from the database. Predominance was observed in the oropharyngeal/neck category (60.3%). For all sites, the mean patient age was 6.7 years (range, 0-18 years), with a 51.7% male predominance. There was a high occurrence in the North East Central region of the United States. Overall, methicillin-resistant S aureus was seen in 21.6% of all patient isolates (n = 4534), with rates of 11.8%, 12.5%, 18.1%, 27.2%, 25.5%, and 28.1% for 2001 through 2006, respectively. This represents a 16.3% increase in methicillin-resistant S aureus during these 6 years for all pediatric head and neck S aureus infections. Conclusions There is an alarming nationwide increase in the prevalence of pediatric methicillin-resistant S aureus head and neck infections. Disparities in the treatment of various head and neck infections nationwide may contribute to the regional differences in the prevalence of such infections. Judicious use of antibiotic agents and increased effectiveness in diagnosis and treatment are warranted to reduce further antimicrobial drug resistance in pediatric head and neck infections.