Corrosion-protective coatings from electrically conducting polymers

In a joint effort between NASA Kennedy and LANL, electrically conductive polymer coatings were developed as corrosion protective coatings for metal surfaces. At NASA Kennedy, the launch environment consist of marine, severe solar, and intermittent high acid and/or elevated temperature conditions. Electrically conductive polymer coatings were developed which impart corrosion resistance to mild steel when exposed to saline and acidic environments. Such coatings also seem to promote corrosion resistance in areas of mild steel where scratches exist in the protective coating. Such coatings appear promising for many commercial applications

Fundraising, celebrations and classroom rewards are substantial sources of unhealthy foods and beverages on public school campuses

Objective: The emphasis in school nutrition policy has been on vending and competitive items. Our study was designed to characterize and quantify the amount and source of other foods and beverages on school campuses. Design: A cross-sectional observational study was conducted using a specially designed objective nutrition observation system. Setting: One low-income school district in southern California with six elementary and two middle schools. Subjects: Data were not collected from individual children. A total of 4033 students, 42 % of whom were Hispanic/Latino, 26 % African American and 21 % non-Hispanic white, were observed across school settings. Results: Data were collected continuously from 9 January 2008 to 16 June 2010. Healthy foods had, per serving, total energy ≤732 kJ (≤175 kcal), total fat content ≤35 %, total saturated fat ≤10 %, sugar less ≤15 g, sodium <200 mg and trans-fat ≤0·5 g. Healthy beverages were only 100 % juice or water, and unflavoured non-fat, 1 %, 2 % milk and soya or rice milk. The system had high inter-rater reliability (r = 0·78 to 0·99), percentage agreement (83 % to 100 %) and test–retest reliability (r = 0·81 to 0·98). Significantly more unhealthy foods and beverages than healthy items were observed on all campuses (P < 0·001). An average of 1·26 (sd 0·46) items per student per week was found with an average of 0·86 (sd 0·34) unhealthy items per child per week. Conclusions: There were substantial amounts of unhealthy foods and beverages brought onto campuses for classroom rewards, celebrations and fundraising that should be targeted for intervention

Clinician Burnout and Satisfaction with Resources in Caring for Complex Patients

Objective: To describe primary care clinicians\u27 self-reported satisfaction, burnout and barriers for treating complex patients. Methods: We conducted a survey of 1554 primary care clinicians in 172 primary care clinics in 18 health care systems across 8 states prior to the implementation of a collaborative model of care for patients with depression and diabetes and/or cardiovascular disease. Results: Of the clinicians who responded to the survey (n=709; 46%), we found that a substantial minority (31%) were experiencing burnout that was associated with lower career satisfaction (P\u3c.0001) and lower satisfaction with resources to treat complex patients (P\u3c.0001). Less than 50% of clinicians rated their ability to treat complex patients as very good to excellent with 21% rating their ability as fair to poor. The majority of clinicians (72%) thought that a collaborative model of care would be very helpful for treating complex patients. Conclusions: Burnout remains a problem for primary care clinicians and is associated with low job satisfaction and low satisfaction with resources to treat complex patients. A collaborative care model for patients with mental and physical health problems may provide the resources needed to improve the quality of care for these patients

Scanning Electron Microscopy Analysis of Polyethylene Oxide Hydrogels for Blood Contact

Hydrogels are a class of synthetic material, composed of a polymer-water matrix and have been proposed as tissue substitutes and drug delivery vehicles. Polyethylene oxide (PEO) hydrogels were synthesized and used to produce coated wires and conduits for baboon blood compatibility studies. Blood-material interactions were studied both by Scanning Electron Microscopy (SEM) and 111In labeled platelet deposition. SEM processing modifications were first evaluated in order to reduce shrinkage and surface distortion incurred during sample preparation of these high water content materials. Pretreatment with 1% tannic acid reduced bulk shrinkage associated with critical point drying by 10-20%. This effect is small, nevertheless, it prevented major sample disruption. Coated guidewires were exposed to baboon blood for one hour in the inferior vena cava and conduits were placed for either 30 or 60 minutes in an ex vivo femoral arteriovenous shunt. Reference materials included Gore-tex®, polyethylene and silica-free polydimethyl siloxane (PDMS). In the guidewire studies, 111In labeled platelet levels were highest on Gore-tex® (6568.97 platelets/ 1000 μm2) and large thrombotic deposits were well visualized by SEM. Formulations containing PEO had low levels of platelet deposition and little evidence of platelet activation was noted by SEM. Shunt studies demonstrated that materials of high PEO content and molecular weight had the lowest levels of platelet deposition. After 60 minutes of blood flow, mean platelet deposition on PDMS and Gore-tex® was 50 and 1000 fold higher than on a network composed of 65% PEO 20,000 (p \u3c 0.05). SEM confirmed these findings

Beyond the Beta Rebound: Post-Task Responses in Oscillatory Activity follow Cessation of Working Memory Processes

Post-task responses (PTRs) are transitionary responses occurring for several seconds between the end of a stimulus/task and a period of rest. The most well-studied of these are beta band (13 – 30 Hz) PTRs in motor networks following movement, often called post-movement beta rebounds, which have been shown to differ in patients with schizophrenia and autism. Previous studies have proposed that beta PTRs reflect inhibition of task-positive networks to enable a return to resting brain activity, scaling with cognitive demand and reflecting cortical self-regulation. It is unknown whether PTRs are a phenomenon of the motor system, or whether they are a more general self-modulatory property of cortex that occur following cessation of higher cognitive processes as well as movement. To test this, we recorded magnetoencephalography (MEG) responses in 20 healthy participants to a working-memory task, known to recruit cortical networks associated with higher cognition. Our results revealed PTRs in the theta, alpha and beta bands across many regions of the brain, including the dorsal attention network (DAN) and lateral visual regions. These PTRs increased significantly (p < 0.05) in magnitude with working-memory load, an effect which is independent of oscillatory modulations occurring over the task period as well as those following individual stimuli. Furthermore, we showed that PTRs are functionally related to reaction times in left lateral visual (p < 0.05) and left parietal (p < 0.1) regions, while the oscillatory responses measured during the task period are not. Importantly, motor PTRs following button presses did not modulate with task condition, suggesting that PTRs in different networks are driven by different aspects of cognition. Our findings show that PTRs are not limited to motor networks but are widespread in regions which are recruited during the task. We provide evidence that PTRs have unique properties, scaling with cognitive load and correlating significantly with behaviour. Based on the evidence, we suggest that PTRs inhibit task-positive network activity to enable a transition to rest, however, further investigation is required to uncover their role in neuroscience and pathology

HPA axis related genes and response to psychological therapies: genetics and epigenetics

Background Hypothalamic–pituitary–adrenal (HPA) axis functioning has been implicated in the development of stress-related psychiatric diagnoses and response to adverse life experiences. This study aimed to investigate the association between genetic and epigenetics in HPA axis and response to cognitive behavior therapy (CBT). Methods Children with anxiety disorders were recruited into the Genes for Treatment project (GxT, N = 1,152). Polymorphisms of FKBP5 and GR were analyzed for association with response to CBT. Percentage DNA methylation at the FKBP5 and GR promoter regions was measured before and after CBT in a subset (n = 98). Linear mixed effect models were used to investigate the relationship between genotype, DNA methylation, and change in primary anxiety disorder severity (treatment response). Results Treatment response was not associated with FKBP5 and GR polymorphisms, or pretreatment percentage DNA methylation. However, change in FKBP5 DNA methylation was nominally significantly associated with treatment response. Participants who demonstrated the greatest reduction in severity decreased in percentage DNA methylation during treatment, whereas those with little/no reduction in severity increased in percentage DNA methylation. This effect was driven by those with one or more FKBP5 risk alleles, with no association seen in those with no FKBP5 risk alleles. No significant association was found between GR methylation and response. Conclusions Allele-specific change in FKBP5 methylation was associated with treatment response. This is the largest study to date investigating the role of HPA axis related genes in response to a psychological therapy. Furthermore, this is the first study to demonstrate that DNA methylation changes may be associated with response to psychological therapies in a genotype-dependent manner

Doctoral Recital

Program listing performers and works performe