150 research outputs found

    Pediatric Thyroid Carcinoma Incidence and Temporal Trends in the USA (1973–2007): Race or Shifting Diagnostic Paradigm?

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    Pediatric thyroid carcinoma is relatively uncommon. But variability in incidence rate by race, sex, age at onset/diagnosis, and geographic local had been observed in adult thyroid carcinoma in the USA. We aimed to examine the patterns, rates, and temporal trends of thyroid carcinoma among pediatric patients (0–19 years) between 1973 and 2007. The Surveillance, Epidemiology, and End Results (SEER) data of the National Cancer Institute were utilized. Data were available on sex, age at diagnosis, race/ethnicity, and geographic locale (9 SEER registries) and were used for rates and trends computation. The frequency and percentage, percent changes (PCs) were calculated by using 1 year of each endpoint. Similarly, the annual percent changes (APCs) were calculated as well, with APCs estimated using weighted least square methods. Between 1973 and 2007, 1,360 thyroid cancer cases were ascertained in the 9 SEER areas (n = 247,638,734) in the USA. The percent change was 47.9, while the APC was significantly different from 0, 1.0 (95% CI: 0.5–1.6, P < 0.0001). The rate ratio (RR) was significantly lower in 1975 (RR: 0.62, 95% CI: 0.38–0.98, P = 0.03) relative to the rate between 1973 and 2007 (RR: 1.60, per 100,000, 95% CI: 1.50–1.70), but higher in 2007 (RR: 2.3 per 100,000, 95% CI: 1.70–3.10; RR: 1.44, 95% CI: 1.05–1.93, P = 0.02). The rate was significantly higher in whites relative to blacks, highest among age group of 15–19 years and girls, and in some SEER registries, with some significant PC in Connecticut. This temporal trend study of pediatric thyroid carcinoma indicates increase in the rate of this malignancy given the percent change and the annual percent change between 1973 and 2007. In addition, the incidence was higher among girls, lower among blacks, highest in age group of 15–19 years, and relatively higher in SEER registries with predominantly white or Hispanic populations

    Measurement and Mitigation of Optical, Recombination and Resistive Losses in Silicon Photovoltaics

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    Today, most of the photovoltaic cells in the market are made of silicon. Great achievements are being attained every year in terms of reducing the price of this kind of cells and improving their efficiency, reliability and durability. However, further improving the cell performance is a challenging task because of the presence of optical, recombination and resistive loss mechanisms in the cell. This work is focused on the measurement and mitigation of these losses. Mitigation of the optical, recombination and resistive losses at first require quantifying those losses and their impacts on the cell performance metrics accurately. Traditionally, solar cells have been measured using characterization techniques like current-voltage, and Suns-Voc, which express the performance metrics in terms of the global cell parameters for the entire cell. However, solar cell is a large area device and different parts on a cell produce different amount of electricity because of the nonuniform distribution of the crystalline defects over the cell and the process variations. Spatial distributions of the cell parameters are valuable because they provide the in depth information about the root causes behind the performance drop of a cell, and points to its remedy. Camera based luminescence imaging and point by point measurement of quantum efficiency and reflectance on the cell are used in this work to find the spatial distribution of the parameters. A new method of parameter imaging is implemented by incorporating the quantum efficiency scanning with the luminescence measurement. A comprehensive methodology to evaluate losses and process variations in silicon solar cell manufacturing is also presented here. The nature of the distributions and correlations in this study provide important insights about loss mechanisms in industrial solar cells, helping to prioritize efforts for optimizing the performance of the production line. As an effort to mitigate the optical, recombination and resistive losses in the silicon solar cells, self-assembled multifunctional nanostructures are developed. These nanostructures can reduce the optical losses in the near band edge, thus contribute in increasing the photogenerated current density. They also contribute in reducing the surface recombination loss by passivating the silicon surface. Additionally, they shows promising results in reducing spreading resistance, which eventually helps the charge transport mechanism in the cell. An overview of the recent trends and endeavors in silicon photovoltaics is first given, followed by a chapter on the important concepts in silicon photovoltaics. The next chapter describes the solar cell manufacturing process and different performance issues related to it. Chapter 4 introduces different measurement techniques used for quantifying the optical, recombination and resistive losses. The following chapters present the crux of this work: method developed for measurement and mitigation of optical, recombination and resistive losses in silicon photovoltaics

    Promoting Adherence to Influenza Vaccination Recommendations in Pediatric Practice.

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    OBJECTIVES: In the United States, nonadherence to seasonal influenza vaccination guidelines for children and adolescents is common and results in unnecessary morbidity and mortality. We conducted a quality improvement project to improve vaccination rates and test effects of 2 interventions on vaccination guidelines adherence. METHODS: We conducted a cluster randomized control trial with 11 primary care practices (PRACTICE) that provided care for 11 293 individual children and adolescents in a children\u27s health care system from September 2015 through April 2016. Practice sites (with their clinicians) were randomly assigned to 4 arms (no intervention [Control], computerized clinical decision support system [CCDSS], web-based training [WBT], or CCDSS and WBT [BOTH]). RESULTS: During the study, 55.8% of children and adolescents received influenza vaccination, which improved modestly during the study period compared with the prior influenza season ( P = .009). Actual adherence to recommendations, including dosing, timeliness, and avoidance of missed opportunities, was 46.4% of patients cared for by the PRACTICE. The WBT was most effective in promoting adherence with vaccination recommendations with an estimated average odds ratio = 1.26, P \u3c .05, to compare between preintervention and intervention periods. Over the influenza season, there was a significantly increasing trend in odds ratio in the WBT arm ( P \u3c .05). Encouraging process improvements and providing longitudinal feedback on monthly rate of vaccination sparked some practice changes but limited impact on outcomes. CONCLUSIONS: Web-based training at the start of influenza season with monthly reports of adherence can improve correct dose and timing of influenza vaccination with modest impact on overall vaccination rate

    Outcome Measures with COPM of Children using a Wilmington Robotic Exoskeleton

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    Background: The Wilmington Robotic Exoskeleton (WREX) is a body-powered, four degrees of freedom orthosis that allows gravity-minimized movement of the arm at the shoulder and elbow. We sought to measure patient satisfaction and performance with use of the WREX during activities of daily living, play, and at school. Method: Twenty-five families completed a phone interview based on the Canadian Occupational Performance Measure (COPM). These families all had a child, aged 2 to 21years, who had a neuromuscular disorder and who had used the WREX for at least eight months. The parents rated their child’s performance of and satisfaction with important activities both with and without the WREX. The scores were assessed for change between the two conditions. Results: Twenty-four out of the 25 parents reported that their child had greater levels of performance and satisfaction when they were wearing the WREX. The mean change in performance score was 3.61 points, and the mean change in satisfaction score was 4.44 points. Conclusion: Families who have a child diagnosed with a neuromuscular disorder and who uses the WREX perceived improved performance and satisfaction with the WREX during self-chosen meaningful activities

    Lung Rest During Extracorporeal Membrane Oxygenation for Neonatal Respiratory Failure-Practice Variations and Outcomes.

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    OBJECTIVE: Describe practice variations in ventilator strategies used for lung rest during extracorporeal membrane oxygenation for respiratory failure in neonates, and assess the potential impact of various lung rest strategies on the duration of extracorporeal membrane oxygenation and the duration of mechanical ventilation after decannulation. DATA SOURCES: Retrospective cohort analysis from the Extracorporeal Life Support Organization registry database during the years 2008-2013. STUDY SELECTION: All extracorporeal membrane oxygenation runs for infants less than or equal to 30 days of life for pulmonary reasons were included. DATA EXTRACTION: Ventilator type and ventilator settings used for lung rest at 24 hours after extracorporeal membrane oxygenation initiation were obtained. DATA SYNTHESIS: A total of 3,040 cases met inclusion criteria. Conventional mechanical ventilation was used for lung rest in 88% of cases and high frequency ventilation was used in 12%. In the conventional mechanical ventilation group, 32% used positive end-expiratory pressure strategy of 4-6 cm H2O (low), 22% used 7-9 cm H2O (mid), and 43% used 10-12 cm H2O (high). High frequency ventilation was associated with an increased mean (SEM) hours of extracorporeal membrane oxygenation (150.2 [0.05] vs 125 [0.02]; p \u3c 0.001) and an increased mean (SEM) hours of mechanical ventilation after decannulation (135 [0.09] vs 100.2 [0.03]; p = 0.002), compared with conventional mechanical ventilation among survivors. Within the conventional mechanical ventilation group, use of higher positive end-expiratory pressure was associated with a decreased mean (SEM) hours of extracorporeal membrane oxygenation (high vs low: 136 [1.06] vs 156 [1.06], p = 0.001; mid vs low: 141 [1.06] vs 156 [1.06]; p = 0.04) but increased duration of mechanical ventilation after decannulation in the high positive end-expiratory pressure group compared with low positive end-expiratory pressure (p = 0.04) among survivors. CONCLUSIONS: Wide practice variation exists with regard to ventilator settings used for lung rest during neonatal respiratory extracorporeal membrane oxygenation. Use of high frequency ventilation when compared with conventional mechanical ventilation and use of low positive end-expiratory pressure strategy when compared with mid positive end-expiratory pressure and high positive end-expiratory pressure strategy is associated with longer duration of extracorporeal membrane oxygenation. Further research to provide evidence to drive optimization of pulmonary management during neonatal respiratory extracorporeal membrane oxygenation is warranted

    Characterization of Pediatric Acute Lymphoblastic Leukemia Survival Patterns by Age at Diagnosis

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    Age at diagnosis is a key prognostic factor in pediatric acute lymphoblastic leukemia (ALL) survivorship. However, literature providing adequate assessment of the survival variability by age at diagnosis is scarce. The aim of this study is to assess the impact of this prognostic factor in pediatric ALL survival. We estimated incidence rate of mortality, 5-year survival rate, Kaplan-Meier survival function, and hazard ratio using the Surveillance Epidemiology and End Results (SEER) data during 1973–2009. There was significant variability in pediatric ALL survival by age at diagnosis. Survival peaked among children diagnosed at 1–4 years and steadily declined among those diagnosed at older ages. Infants (<1 year) had the lowest survivorship. In a multivariable Cox proportional hazard model stratified by year of diagnosis, those diagnosed in age groups 1–4, 5–9, 10–14, and 15–19 years were 82%, 75%, 57%, and 32% less likely to die compared to children diagnosed in infancy, respectively. Age at diagnosis remained to be a crucial determinant of the survival variability of pediatric ALL patients, after adjusting for sex, race, radiation therapy, primary tumor sites, immunophenotype, and year of diagnosis. Further research is warranted to disentangle the effects of age-dependent biological and environmental processes on this association

    Influence of body mass index and antibiotic dose on the risk of surgical site infections in pediatric clean orthopedic surgery.

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    OBJECTIVE: To evaluate body mass index (BMI) and antimicrobial dose as risk factors for surgical site infections in pediatric patients. PATIENTS AND METHODS: Children between 2 and 19 years of age undergoing clean orthopedic procedures and receiving at least one dose of perioperative antibiotics (cefazolin, vancomycin, or clindamycin) were studied. The retrospective case-controlled study was conducted at the Alfred I. duPont Hospital for Children, a 180-bed tertiary-care academic pediatric hospital in Wilmington, DE. Data were collected from January 1, 2002, to December 31, 2005. RESULTS: Underweight children had a higher risk for SSIs than overweight and normal-weight children. American Society of Anesthesiologists classes II and greater were associated with a greater risk of SSI. Longer procedures were also associated with a higher risk of SSI, specifically, duration of surgery \u3e2 h. Children weighing ≥70 kg who received a standard dose of cefazolin (maximum of 1 g) had a higher risk of SSI caused by methicillin-sensitive Staphylococcus aureus (MSSA). CONCLUSIONS: Being underweight and undergoing an operation lasting \u3e2 h created significant risks for SSI. Children weighing ≥70 kg receiving a standard 1-g dose of cefazolin had a greater risk of MSSA SSIs than children weighingantibiotic

    A double-blind randomized trial of fish oil to lower triglycerides and improve cardiometabolic risk in adolescents.

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    OBJECTIVES: To determine the efficacy of 4 g/day fish oil to lower triglycerides and impact lipoprotein particles, inflammation, insulin resistance, coagulation, and thrombosis. STUDY DESIGN: Participants (n = 42, age 14 ± 2 years) with hypertriglyceridemia and low-density lipoprotein (LDL) cholesterol/dL were enrolled in a randomized, double-blind, crossover trial comparing 4 g of fish oil daily with placebo. Treatment interval was 8 weeks with a 4-week washout. Lipid profile, lipoprotein particle distribution and size, glucose, insulin, high-sensitivity C-reactive protein, interleukin-6, fibrinogen, plasminogen activator inhibitor-1, and thrombin generation were measured. RESULTS: Baseline lipid profile was total cholesterol 194 (5.4) mg/dL (mean [SE]), triglycerides 272 (21) mg/dL, high-density lipoprotein cholesterol 39 (1) mg/dL, and LDL cholesterol 112 (3.7) mg/dl. LDL particle number was 1614 (60) nmol/L, LDL size was 19.9 (1.4) nm, and large very low-density lipoprotein/chylomicron particle number was 9.6 (1.4) nmol/L. Triglycerides decreased on fish oil treatment but the difference was not significant compared with placebo (-52 ± 16 mg/dL vs -16 ± 16 mg/dL). Large very low-density lipoprotein particle number was reduced (-5.83 ± 1.29 nmol/L vs -0.96 ± 1.31 nmol/L; P \u3c .0001). There was no change in LDL particle number or size. There was a trend towards a lower prothrombotic state (lower fibrinogen and plasminogen activator inhibitor-1; .10 \u3e P \u3e .05); no other group differences were seen. CONCLUSIONS: In children, fish oil (4 g/day) lowers triglycerides slightly and may have an antithrombotic effect but has no effect on LDL particles
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