Examination of radio‐opacity enhancing additives in shape memory polyurethane foams

Three microparticle additives, tungsten (W), zirconium oxide (ZrO₂) , and barium sulfate (BaSO₄) were selected to enhance the radio‐opacity in shape memory polymer (SMP) foam biomaterials. The addition of filler causes no significant alterations of glass transition temperatures, density of the materials increases, pore diameter decreases, and total volume recovery decreases from approximately 70 times in unfilled foams to 20 times (4% W and 10% ZrO₂). The addition of W increases time to recovery; ZrO₂ causes little variation in time to shape recovery; BaSO₄ increases the time to recovery. On a 2.00 mean X‐ray density (mean X.D.) scale, a GDC coil standard has a mean X.D. of 0.62 ; 4% W enhances the mean X.D. to 1.89, 10% ZrO₂ to 1.39 and 4% BaSO₄ to 0.74. Radio‐opacity enhancing additives could be used to produce SMP foams with controlled shape memory kinetics, low density , and enhanced X ‐ray opacity for medical materials. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42054.     

A longitudinal investigation of anxiety sensitivity in adolescence.

This investigation sought to expand existing knowledge of anxiety sensitivity in a sample of high school students (N = 2,365) assessed over 4 years. The stability of anxiety sensitivity levels across assessment periods was examined, and cluster analyses were used to identify different developmental pathways in levels of anxiety sensitivity. Groups of adolescents with stable low, stable high, and escalating anxiety sensitivity levels were identified. Adolescents with stable high or escalating anxiety sensitivity were significantly more likely to report experiencing a panic attack than individuals with stable low anxiety sensitivity. Results also indicated that Asian and Hispanic adolescents tended to report higher anxiety sensitivity but that their anxiety sensitivity was less strongly associated with panic than that of Caucasian adolescents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Report on workshop on high performance computing and communicationsfor grand challenge applications: computer vision, speech and naturallanguage processing, and artificial intelligence

The findings of a workshop, the goals of which were to identify applications, research problems, and designs of high performance computing and communications (HPCC) systems for supporting applications are discussed. In computer vision, the main scientific issues are machine learning, surface reconstruction, inverse optics and integration, model acquisition, and perception and action. In speech and natural language processing (SNLP), issues were identified statistical analysis in corpus-based speech and language understanding, search strategies for language analysis, auditory and vocal-tract modeling, integration of multiple levels of speech and language analyses, and connectionist systems. In AI, important issues that need immediate attention include the development of efficient machine learning and heuristic search methods that can adapt to different architectural configurations, and the design and construction of scalable and verifiable knowledge bases, active memories, and artificial neural networks     

Theoretical psychology: Subdiscipline or metadiscipline?

Comments on the article by B. D. Slife and R. N. Williams (see record 84-17550) concerning theoretical psychology as a subdiscipline of psychology. Considerations that may add to continuing positive discourse concerning a theoretical subdiscipline are presented. It is believed that efforts to avoid the development of any gulf between theoretical psychology and other areas of psychology should be given high priority in future discourse concerning the development of a subdiscipline of theoretical psychology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Shape memory polyurethane-urea foams with improved toughness

Current vascular aneurysm treatments often require either highly invasive strategy to surgically occlude an aneurysm or endovascular occlusion via metal coils. While endovascular coils are safer, they have limited efficacy. Endovascular coils that are integrated with shape memory polymer (SMP) foams have the potential to improve occlusion and reduce coil risks; however, the mechanical performance and limited homogeneity of SMP foams can hinder their effective use. To address this issue, SMP foams are synthesized using the monomer diethanolamine (DEA) in place of triethanolamine (TEA) to provide improved mechanical properties for medical device applications. Mechanical testing and micro-fracture analysis were performed on DEA and TEA foams. DEA foams show improved toughness and reduced micro-fractures compared to the control. This work presents the utility of DEA in SMP synthesis to enable the potential production of safer aneurysm treatment. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47268.     

A Novel Design of a Metacarpal/MetatarsaI-Phalangeal Total Joint Replacement

Arthritis, most notably rheumatoid arthritis, can destroy the surfaces of the bones; the ideal solution for this is T JR （total joint replacement）, which would restore joint functionality, maintain correct aesthetics and eradicate pain for the patient. Current metacarpophalangeal TJR do not provide the normal biomechanical range of motion and functionality. The proposed design attempts to correct this through the use of design geometry and functional anatomy. Numerical analysis is used in conjunction with computational solid modeling to compare a one-piece silicone implant with the proposed T JR. Peak stresses during flexion for the proposed design did not exceed 1.2 MPa, where as soft implants approach 100 MPa to 1,000 MPa for peak stress values. The proposed design, due to high stress tolerances with low deformation, along with functionality and biomechanics, seems to be an appropriate replacement for one-piece silicone implant.     

What do youth report as a traumatic event? Toward a developmentally informed classification of traumatic stressors.

This study explored youth reports of traumatic events by (a) identifying the types of events that children and adolescents report as traumatic in their lives, (b) investigating the association between self-reported traumatic events and self- and parent-reported emotional problems, and (c) examining developmental differences in the type and severity of the events reported as traumatic. Findings suggest that youth reported as traumatic a wide variety of experiences that could be reliably coded and classified and that youth reporting traumatic events and symptoms consistent with posttraumatic stress disorder evidence higher levels of emotional and behavioral problems (via parent and child report) than youth not reporting traumatic events. Youth ages 13–17 tended to report traumas that were rated by independent coders as more severe than did youth ages 6–12. Although the types of events reported did not differ in posttraumatic stress disorder symptoms and other emotional and behavioral problems, there were differences in objective ratings of physical severity and psychological intensity. Implications of the findings are discussed in terms of the creation of developmentally informed classification of traumatic stressors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Improved oxidative biostability of porous shape memory polymers by substituting triethanolamine for glycerol

While many aromatic polyurethane systems suffer from poor hydrolytic stability, more recently proposed aliphatic systems are oxidatively labile. The use of the renewable monomer glycerol as a more oxidatively resistant moiety for inclusion in shape memory polymers (SMPs) is demonstrated here. Glycerol-containing SMPs and the amino alcohol control compositions are compared, with accelerated degradation testing displaying increased stability (time to complete mass loss) as a result of the inclusion of glycerol without sacrificing the shape memory, thermal transitions, or the ultralow density achieved with the control compositions. Gravimetric analysis in accelerated oxidative solution indicates that the control will undergo complete mass loss by approximately 18 days, while lower concentrations of glycerol will degrade fully by 30 days and higher concentrations will possess approximately 40% mass at the same time. In real-time degradation analysis, high concentrations of glycerol SMPs have 96% mass remaining at 8 months with 88% gel fraction remaining that that time, compared to less than 50% mass for the control samples with 5% gelation. Mechanically, low glycerol-containing SMPs were not robust enough for testing at three months, while high glycerol concentrations displayed increased elastic moduli (133% of virgin materials) and 18% decreased strain to failure. The role of the secondary alcohol, as well as isocyanates, is presented as being a crucial component in controlling degradation; a free secondary alcohol can more rapidly undergo oxidation or dehydration to ultimately yield carboxylic acids, aldehydes, carbon dioxide, and alkenes. Understanding these pathways will improve the utility of medical devices through more precise control of property loss and patient risk management through reduced degradation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47857.