Effect of Nanoscale Confinement on Polymer-Infiltrated Scaffold Metal Composites.

Most research on polymer composites has focused on adding discrete inorganic nanofillers to a polymer matrix to impart properties not found in polymers alone. However, properties such as ion conductivity and mechanical reinforcement would be greatly improved if the composite exhibited an interconnected network of inorganic and polymer phases. Here, we fabricate bicontinuous polymer-infiltrated scaffold metal (PrISM) composites by infiltrating polymer into nanoporous gold (NPG) films. Polystyrene (PS) and poly(2-vinylpyridine) (P2VP) films are infiltrated into the ∼43 nm diameter NPG pores via capillary forces during thermal annealing above the polymer glass transition temperature (Tg). The infiltration process is characterized in situ using spectroscopic ellipsometry. PS and P2VP, which have different affinities for the metal scaffold, exhibit slower segmental dynamics compared to their bulk counterparts when confined within the nanopores, as measured through Tg. The more attractive P2VP shows a 20 °C increase in Tg relative to its bulk, while PS only shows a 6 °C increase at a comparable molecular weight. The infiltrated polymer, in turn, stabilizes the gold nanopores against temporal coarsening. The broad tunability of these polymer/metal hybrids represents a unique template for designing functional network composite structures with applications ranging from flexible electronics to fuel cell membranes.

Using X-Ray Scattering to Elucidate the Microstructural Instability of 3D Bicontinuous Nanoporous Metal Scaffolds for Use in an Aperiodic 3D Tricontinuous Conductor-Insulator-Conductor Nanocapacitor.

The development of three-dimensional aperiodic energy storage devices is in part impeded by the lack of appropriate aperiodic templates that can withstand the thermal conditions required to deposit energy storage materials within their void space. Herein, the feasibility of an aperiodic three-dimensional architecture for energy storage is demonstrated for the first time by constructing a tricontinuous conductor-insulator-conductor (CIC) nanocapacitor on an aperiodic nanoporous gold scaffold. To accomplish this, the scaffold was characterized using in situ small-angle X-ray scattering (SAXS) during exposure to a thermal environment, revealing that its microstructure eventually stabilizes after undergoing a phase of rapid coarsening, indicating a departure from the 1/4 time-dependent power-law coarsening behavior usually observed at the early stage of the coarsening process. Using this stability regime, we created the CIC by intentionally precoarsening and stabilizing the scaffold before depositing two dissimilar metal oxide films in its void space by atomic layer deposition. Current-voltage characteristics and electrochemical impedance spectroscopy measurements revealed that the un-optimized 3D CIC outperformed its 2D counterpart by ∼4× in terms of capacitance. This proof-of-concept device will pave the way to the development of aperiodic three-dimensional energy storage systems with enhanced energy and power densities.

Daily changes in pain, mood and physical function in children hospitalized for sickle cell disease pain.

BACKGROUND: Youth with sickle cell disease (SCD) are commonly hospitalized for treatment of painful vaso-occlusive episodes (VOE). However, limited data are available concerning the course of hospitalization for these children and adolescents and, in particular, whether daily changes occur in pain, emotional status and physical function. OBJECTIVES: To characterize changes in daily pain intensity, physical function and mood over the course of hospitalization, and to determine whether specific clinical characteristics were associated with these changes. METHODS: Daily ratings of pain (0 to 10 numerical rating scale) and mood (Positive and Negative Affect Scale for Children) were completed by 25 youth (11 to 20 years of age) with SCD over a total of 152 days (mean [± SD] = 6.7±5.6 days) of hospitalization. Trained raters determined each youth's daily physical function. RESULTS: Linear mixed modelling was used to examine changes in pain, mood and physical function during hospital stay. The rate of change over the course of hospitalization was significant for reductions in pain intensity (P<0.001) and improvements in physical (motor) function (P=0.001). Positive affect over time was significantly associated with subjects' physical function scores (B 0.24 [95% CI 0.12 to 0.35]) but not with their pain scores. In contrast, negative affect was positively associated with pain and inversely associated with physical function scores (B 1.58 [95% CI 0.23 to 2.93]). CONCLUSIONS: The results of the present study demonstrated that children made daily improvements in physical function and pain over hospitalization for VOE. Mood was related to changes in pain and physical recovery. Assessment of physical function and mood during hospitalization may help guide strategies to better understand the pain experience in youth with SCD hospitalized with VOE.

Pain scores: are they used in sickle cell pain?

OBJECTIVES: We sought to evaluate the relationship between pain scores and time to analgesic administration in 2 patient groups: those with sickle cell disease (SCD) and those with long-bone fractures (LBFs). METHODS: Patients between the ages of 3 and 21 years who presented to a pediatric emergency department (ED) with a vaso-occlusive episode secondary to SCD or an isolated LBF during 2005 were included. A retrospective chart review was conducted for each visit. Data collected included demographics, visual analog scale (VAS) pain scores, and time analgesic intervention. In 2005, all patients with SCD received analgesic management according to protocol. RESULTS: Seventy-seven patients with SCD had 152 visits to the ED for pain, whereas 219 patients had 221 visits for isolated LBF. In the long-bone-fracture group, for every 1-point increase in the VAS score, time to analgesic administration decreased by 5.6 minutes (P = 0.003), whereas in the SCD group, there was no relationship between VAS score and time to analgesic administration (P = 0.69). CONCLUSIONS: Our data suggest that pain scores are not used in the initial decision-making process in those patients with SCD presenting to the ED; however, they are utilized for patients presenting with another painful condition.

All-terrain vehicle riding among youth: how do they fair?

PURPOSE: Pediatric all-terrain vehicle (ATV) injuries have been increasing annually for more than a decade. The objective of this study was to describe the riding behaviors, helmet use, and crash history of young ATV riders. METHODS: A 38 question self-administered survey was distributed to a convenience sample of children at 4 agricultural fairs during 2007. A total of 228 surveys were reviewed. Collected data included demographic information, ATV characteristics, helmet use, driving habits, and crash history. RESULTS: Survey respondents were predominantly male (71%) with an average age of 13.6 +/- 2.0 years. Riding began at a young age (9.2 +/- 3.2 years). Few children reported using age-appropriate sized engines (3% < 90 cm(3)), and 22% of children rode ATVs with engines more than 300 cm(3). Respondents rode primarily for recreation (94%), and more than a third reported riding without a helmet (40%). More than 70% of children reported riding with passengers, 60% without adult supervision, and nearly half (46%) rode after dark. Less than 5% of riders received any formal ATV riding/safety instruction. Of the respondents, 45% reported being involved in an ATV crash. Those children who reported a crash also rode more powerful ATVs, were more often self-taught, and overall reported higher rates of riding with passengers and without supervision, and riding after dark (P < .05). CONCLUSION: Dangerous driving behavior among children who ride ATVs is widespread, and current safety recommendations are largely ignored. Renewed efforts are needed to improve safety programs and create policy measures that prevent pediatric ATV crash-related injuries.

Emergent endotracheal intubations in children: be careful if it's late when you intubate.

OBJECTIVE: Emergent endotracheal intubations carry a high risk of morbidity and mortality in critically ill adults. Although children may be at higher risk during this procedure as a result of age-related differences in anatomy and physiology, this has not been previously examined. The purpose of this study was to delineate the risks of emergent endotracheal intubations in children. DESIGN: Retrospective cohort study. SETTING: A 122-bed free-standing children's hospital. PATIENTS: We conducted a retrospective review of all intubations occurring outside of the operating room setting between October 2005 and October 2007. Elective intubations were excluded. Intubations were classified as emergent after review of the child's vital signs, blood gas values, and written documentation by nurses, respiratory therapists, and physicians. Intubations occurring on weekends or between 5 pm and 8 am on weekdays were categorized as "off-hours." INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: During the study period, 137 intubations were performed, 77 of which (56%) were emergent. Emergent endotracheal intubations were significantly more likely to occur off-hours (odds ratio, 2.0; 95% confidence interval, 1.1-4.1) and to be associated with a complication (odds ratio, 3.0; 95% confidence interval, 1.4-6.1). Complications occurred in 41% of all intubations. The most common complications were desaturations (29% of all intubations), hypotension (16%), and bradycardia (7%). In a multivariate logistic regression analysis, emergent intubation, off-hours intubation, three or more attempts at intubation, smaller endotracheal tube size, and admission for cardiovascular disease all increased the likelihood of experiencing a complication during intubation. Complications were not associated with an indication for intubation or baseline chronic disease of the child and were not associated with prolonged intensive care unit course or duration of mechanical ventilation. CONCLUSIONS: Emergent endotracheal intubations are commonly performed in children, are two times more likely to occur off-hours, and are associated with three times the risk of complications as nonemergent intubations.

Use of low-dose ketamine infusion for pediatric patients with sickle cell disease-related pain: a case series.

OBJECTIVES: Sickle cell disease-related pain is difficult to treat adequately. Pain secondary to vasoocclusive episodes (VOE) may be unresponsive to high-dose intravenous opiates. Alternative treatment options for VOE are needed. We sought to review our experience with low-dose ketamine for children hospitalized with VOE. METHODS: Retrospective medical chart reviews were conducted for hospitalized patients treated with ketamine for sickle cell VOE. Data gathered included vital signs, pain scores, opiate utilization, and adverse events. RESULTS: Five children and adolescents received a low-dose ketamine infusion for the treatment of sickle cell-related pain. Four received the infusion in addition to opiates (delivered via patient controlled analgesia) as a rescue intervention after several days of inadequate pain relief and 1 patient received ketamine in place of opiates. Two of the 5 patients achieved what seems to be clinically significant pain control with a low-dose ketamine infusion, whereas 1 additional patient had significant reduction in opiate utilization. DISCUSSION: Further research into ketamine for vasoocclusive pain is warranted.

Pediatrician attitudes, knowledge, and practice behavior regarding teen driving safety.

PROBLEM: Each year about 4,000 teens ages 16-19 die on U.S. roads. Injury prevention counseling is recommended as a valuable and cost-effective part of routine health supervision. This study describes pediatrician knowledge and practice regarding teen driving safety. METHODS: A 31-item self-administered survey was mailed to pediatricians. RESULTS: 160 of 392 pediatricians (41%) completed the survey. During a health supervision visit 93% of pediatricians reported discussing seat belt use, 89% impaired driving, 54% teen licensing laws, and 16% parent teen contract. Half reported having a teen in their practice killed in a crash. CONCLUSIONS: A majority surveyed report discussing and counseling teens on first wave teen driver safety issues (seat belts, alcohol use), but most do not discuss graduated driver licensing laws or related issues. IMPACT ON INDUSTRY: Broadly adopted, this inexpensive counseling approach, could lead to reductions in teen motorvehicle crash injuries.

Pediatric snakebites: lessons learned from 114 cases.

PURPOSE: Evidence-based guidelines for the treatment of pediatric snakebite injuries are lacking because they occur infrequently in most centers. METHODS: We reviewed our experience treating snakebites from January 1995 through December 2005. Demographic (eg, age, sex, geographic location) and clinical information (eg, location of bite, species of snake, vital signs, laboratories, treatment, hospital length of stay) were obtained. RESULTS: Over the last decade, we have treated 114 children with confirmed snakebites. Mean age was 7.3 +/- 4.2 years (range, 1-17 years), and snakebites were more common in males (n = 68, 60%). All bites occurred on the extremities, and lower extremity bites were more common (n = 71, 62%). Copperheads inflicted the most bite injuries (n = 65, 57%), followed by rattlesnakes (n = 9, 8%) and cottonmouths (n = 7, 6%). The snake was not identified in 33 (29%) cases. Seven (6%) children were treated with Crotalidae antivenin. Of the children treated with antivenin, only 4 met criteria for treatment, and 1 had an anaphylactic reaction. If compartment syndrome was suspected based on neurovascular examination, compartment pressures were measured. Only 2 (1.8%) patients required fasciotomies. Over the last 2 years, we have stopped empiric treatment with antibiotics and have not observed any infectious complications. Average hospital length of stay was 30 +/- 25 hours. CONCLUSIONS: Most children bitten by pit vipers can be managed conservatively with analgesics and elevation of the affected extremity. Treatment with Crotalidae antivenin, antibiotics, and fasciotomy is rarely indicated.

Racial disparities in the management of pediatric appenciditis.

BACKGROUND: Our objective was to compare the racial differences in incidence and management of pediatric appendicitis. MATERIALS AND METHODS: Data for this study come from two large national hospital discharge databases from the Agency for Healthcare Research and Quality Healthcare Costs and Utilization Project: The Nationwide Inpatient Sample (NIS) and the Kids' Inpatient Database (KID). Analysis was restricted to age less than 18 years with an ICD-9 diagnosis of either simple (540.9) or complex (540.0 and 540.1) appendicitis. Data were weighted to represent national estimates. Incidence was defined as the number of new disease cases divided by the number of at risk hospitalized children. RESULTS: The data for this study contained an estimated 428,463 [95% confidence interval (CI) = 414, 672-442, 253] cases of appendicitis, representing approximately 65,000 to 75,000 cases annually. Multi-variant analysis suggests that African-Americans, as compared to Caucasians, were less prone to develop appendicitis [odds ratio (OR) = 0.39, 95% CI (0.38, 0.41)], but less frequently underwent laparoscopic treatment [OR = 0.78, 95% CI (0.74, 0.87)], and were more likely to have complex appendicitis [OR = 1.39, 95% CI (1.30, 1.49)]. In contrast, Hispanics were more likely than Caucasians to both develop appendicitis [OR = 1.48, 95% CI (1.41, 1.56)] and to have complex disease [OR = 1.10, 95% CI (1.05, 1.16)]. The incidence of appendicitis was less frequent in females versus males [OR = 0.69, 95% CI (0.68, 0.70)] but the likelihood of laparoscopic exploration was higher [OR = 1.39, 95% CI (1.34, 1.43)]. Finally, children with public insurance [OR = 1.25, 95% CI (1.21, 1.29)] and uninsured children [OR = 1.10, 95% CI (1.04, 1.16)] were more likely to have complex appendicitis when compared to children with private insurance. CONCLUSIONS: African-American children with appendicitis have lower overall hospitalization rates, higher rates of perforation, a greater delay to surgical management, and lower laparoscopic rates. In contrast, Hispanic children more frequently had appendicitis and complex disease. The treatment of African-American and Hispanic children overall was associated with a longer hospital stay and higher charges. The lower incidence of appendicitis in African-American children is incompletely understood and the disparity in surgical management among minority children remains troubling.