Polypyrrole (PPy) is an inherently conducting polymer that has shown great promise for biomedical applications within the nervous system. However, to effectively use PPy as a biomaterial implant, it is important to understand and reproducibly control the electrical properties, physical topography, and surface chemistry of the polymer. Although there is much research published on the use of PPy in various applications, there is no systematic study linking the methodologies used for PPy synthesis to PPy's basic polymeric properties (e.g., hydrophilicity, surface roughness), and to the biological effects these properties have on cells. Electrochemically synthesized PPy films differ greatly in their characteristics depending on synthesis parameters such as dopant, substrate, and thickness, among other parameters. In these studies, we have used three dopants (chloride (Cl), tosylate (ToS), polystyrene sulfonate (PSS)), two substrates (gold and indium tin oxide-coated glass), and a range of thicknesses, to measure and compare the biomedically-important characteristics of surface roughness, contact angle, conductivity, dopant stability, and cell adhesion (using PC-12 cells and Schwann cells). As predicted, we discovered large differences in roughness depending on the dopant used and the thickness of the film, while substrate choice had little effect. From contact angle measurements, PSS was found to yield the most hydrophilic material, most likely because of free charges from the long PSS chains exposed on the surface of the PPy. ToS-doped PPy films were tenfold more conductive than Cl-or PSS-doped films. X-ray photoelectron spectroscopy studies were used to evaluate dopant concentrations of PPy films stored in water and phosphate buffered saline over 14 days, and conductance studies over the same timeframe measured electrical stability. PSS proved to be the most stable dopant, though all films experienced significant decay in conductivity and dopant concentration. Cell adhesion studies demonstrated the dependence of cell outcome on film thickness and dopant choice. The strengths and weaknesses of different synthesis parameters, as demonstrated by these experiments, are critical design factors that must be leveraged when designing biomedical implants. The results of these studies should provide practical insight to researchers working with conducting polymers, and particularly PPy, on the relationships between synthesis parameters, polymeric properties, and biological compatibility.
Objectives/Hypothesis: To estimate the number, demographics, and outcomes of pediatric patients who underwent tracheostomy in 2012 and to contrast those outcomes by age, race, and gender.Study Design: Cross-sectional study. Methods: The 2012 Kids Inpatient Database was queried to identify tracheostomy patients using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedural codes 311, 3121, and 3129. All patients ≤18 years of age at the time of admission were included and categorized as neonates (≤28 days), infants (>28 days ≤1 year), toddler (1 to 3 years), children (4 to 12 years), adolescents (13 to 17 years), and adults (=18 years). We recorded age, gender, race, insurance status, and zip code of primary residence. We used these variables to contrast the following outcomes: length of stay, total charges, complications of care, and mortality using multiple regression analysis.Results: An estimated 4,424 pediatric tracheostomies occurred during 2012. Fifty-one percent of the patients were ≤3 years old, and 62% were male. Forty-eight percentwere white followed by black (21%), Hispanic (20%), and Asian (3%). The median length of stay was 42 days, and the median total charges were $472,738. The complication rate was 29% and the mortality rate was 8.0%. The length of stay and total charges was predicted by age, with neonates having significantly longer hospitalizations. The complication rate was not associated with age, gender, or ethnicity. However, the mortality rate was associated with younger age.Conclusions: Pediatric tracheostomies are associated with significant hospital utilizations, complications, and mortality. Increased risk of mortality is observed among neonates and infants. Continued study of tracheostomy outcomes among these subsets of the pediatric population are warranted.
Objectives/Hypothesis To study rates of respiratory complications/interventions among inpatient tonsillectomy patients in the United States and identify risk factors for these events. Study Design Retrospective database review. Methods Children (age < 18 years) undergoing tonsillectomy with or without adenoidectomy in 2006, 2009, and 2012 were studied using the Kids Inpatient Database, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality. Outcomes were analyzed for respiratory events (complications/interventions) and racial disparities. Pearson χ test was used to analyze categorical data and regression analysis was used for continuous variables. Respiratory events were analyzed by racial identity using logistic regression analysis. A P < .05 was considered significant. Results The study included 30,617 patients (41% female, 51% white, 24% African American, 23% Hispanic, 3.0% Asian). The mean age was 5.2 years, and mean length of stay 2.3 days. The overall complication rate was 6.0%, and overall intervention rate was 3.6%. Respiratory events were more common among African American children (odds ratio [OR]: 1.5, 95% confidence interval [CI]: 1.3‐1.6) and less common among white children (OR: 0.8, 95% CI: 0.8‐0.9). These differences were significant after controlling for age, gender, obesity, obstructive sleep apnea, and asthma. The mortality rate was 0.05% with no ethnic predilection. Conclusions Respiratory events after inpatient tonsillectomy included laryngo/bronchospasm, pneumonia, pulmonary edema, intubation, prolonged intubation, and ventilation. Although uncommon, these were more common among African American children. Further research is needed to understand the etiology of this disparity. Level of Evidence NA Laryngoscope, 129:995–1000, 2019
Objectives/Hypothesis Determine surgical and swallowing outcomes after surgery for type III laryngotracheoesophageal cleft (LTEC). Study Design Case series with chart review. Methods Chart review was performed on patients with type III LTEC between 2000 and 2019. Demographics, surgical outcomes, and swallowing outcomes were collected and analyzed. Results Thirty‐three patients met inclusion criteria (28 open and 5 endoscopic repairs). Mean age was 3.4 years for the open group and 0.9 years for the endoscopic group. Seventeen (51.5%) patients had a syndromic diagnosis, most commonly Opitz syndrome and Trisomy 21. Mean follow‐up was 33.6 months. Thirteen (39.4%) patients had a previous repair attempt prior to repair at our institution. Twenty‐four (70.6%) patients had a tracheostomy prior to or at the time of surgical repair and 13 (38.2%) remain tracheostomy‐dependent. Nine patients (27.3%) required a revision cleft repair and four (12.1%) required two revisions. Thirty‐one patients had an intact repair at last follow‐up (93.9). Two patients died outside the hospital over a year after surgery. Preoperatively 13 of 17 patients with swallowing evaluations aspirated. After repair, 11 of 20 patients were deemed safe for all consistencies and seven were safe for thickened. Endoscopic approaches were performed during the last 2 years of the study and had significantly lower operative time (354.4 minutes vs. 171.5 minutes). Conclusions Endoscopic and open approaches are effective for treatment of type III LTEC with 27.3% requiring revision and 93.9% of repairs intact at last follow‐up. Overall swallowing outcomes were good in patients who underwent postoperative instrumental swallow evaluation. Level of Evidence 4 Laryngoscope, 132:1112–1117, 2022
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.