Phase-Change Contrast Agents for Imaging and Therapy

Phase-change contrast agents (PCCAs) for ultrasound-based applications have resulted in novel ways of approaching diagnostic and therapeutic techniques beyond what is possible with microbubble contrast agents and liquid emulsions. When subjected to sufficient pressures delivered by an ultrasound transducer, stabilized droplets undergo a phase-transition to the gaseous state and a volumetric expansion occurs. This phenomenon, termed acoustic droplet vaporization, has been proposed as a means to address a number of in vivo applications at the microscale and nanoscale. In this review, the history of PCCAs, physical mechanisms involved, and proposed applications are discussed with a summary of studies demonstrated in vivo. Factors that influence the design of PCCAs are discussed, as well as the need for future studies to characterize potential bioeffects for administration in humans and optimization of ultrasound parameters

Sequences of Tibetan Macaque (Macaca thibetana) and Tourist Behaviors at Mt. Huangshan, China

Previous research on Tibetan macaques (Macaca thibetana) at Mt. Huangshan, China, suggested that ecotourism can have detrimental consequences. This study identified sequences of behaviors that typically occur in macaque-tourist interactions to examine whether particular tourist behaviors precipitate monkey responses. Focal sampling was used to record relevant behaviors from tourists and 10 macaques over 28 data collection sessions in August 2006. Data collectors recorded whether each behavior occurred as part of a sequence. Sequences were defined as two or more behaviors in which each behavior occurred within five seconds of the previous behavior. Of 3,129 total behaviors, 2,539 (81.1%) were from tourists and 590 (18.9%) were from monkeys. Tourists initiated significantly more sequences than did macaques (412 [84.6%] versus 75 [15.4%]). Tourist pointing, rail slapping, fleeing, and rock showing occurred significantly more than expected in tourist-macaque sequences. Points were also among the most common tourist behaviors preceding macaque threats. By discouraging tourists from engaging in these behaviors, macaque threats could be reduced, thereby improving macaque-tourist interactions. These results may aid in the management of other macaque tourist sites to minimize stress-inducing interactions

Intracellular delivery and ultrasonic activation of folate receptor-targeted phase-change contrast agents in breast cancer cells in vitro

Breast cancer is a diverse and complex disease that remains one of the leading causes of death among women. Novel, outside-of-the-box imaging and treatment methods are needed to supplement currently available technologies. In this study, we present evidence for the intracellular delivery and ultrasound-stimulated activation of folate receptor (FR)-targeted phase-change contrast agents (PCCAs) in MDA-MB-231 and MCF-7 breast cancer cells in vitro. PCCAs are lipid-coated, perfluorocarbon-filled particles formulated as nanoscale liquid droplets capable of vaporization into gaseous microbubbles for imaging or therapy. Cells were incubated with 1:1 decafluorobutane (DFB) / octafluoropropane (OFP) PCCAs for 1 hour, imaged via confocal microscopy, exposed to ultrasound (9 MHz, MI = 1.0 or 1.5), and imaged again after insonation. FR-targeted PCCAs were observed intracellularly in both cell lines, but uptake was significantly greater (p < 0.001) in MDA-MB-231 cells (93.0% internalization at MI = 1.0, 79.5% at MI = 1.5) than MCF-7 cells (42.4% internalization at MI = 1.0, 35.7% at MI = 1.5). Folate incorporation increased the frequency of intracellular PCCA detection 45-fold for MDA-MB-231 cells and 7-fold for MCF-7 cells, relative to untargeted PCCAs. Intracellularly activated PCCAs ranged from 500 nm to 6 microns (IQR = 800 nm – 1.5 microns) with a mean diameter of 1.15 ± 0.59 (SD) microns. The work presented herein demonstrates the feasibility of PCCA intracellular delivery and activation using breast cancer cells, illuminating a new platform toward intracellular imaging or therapeutic delivery with ultrasound

Behaviors that Predict Personality Components in Adult free-Ranging Tibetan Macaques (Macaca thibetana)

To further the potential for applied personality studies, we present a methodology for assessing personality in nonhuman animals without a priori assumptions, using behavioral measures to discriminate personality survey results. Our study group consisted of 12 free-ranging, provisioned, adult Tibetan macaques (Macaca thibetana) at the Valley of the Wild Monkeys, China. We asked familiar Chinese park guards and scientists to rate each of the 12 macaques using 27-item personality surveys. We also recorded behavioral observations (\u3e 100 hrs) from August–September, 2012. The personality surveys showed reliability in 22 of the items that were then utilized in a principal component analysis that revealed five components: Insecurity, Reactivity, Boldness, Sociability, and Leadership. Prior personality research on Macaca show comparable components. In order to determine which behaviors would best predict those five personality components, we conducted ­discriminant analyses using behavioral measures as predictors. We found that behavioral measures of avoidance, lunging, fear-grinning, self-directed behaviors, touching, proximity and chasing could significantly predict personality component scores in certain situations. Finally, we analyzed the effects of situation (provisioning and tourists) and found situation influenced proximity and rates of avoidance and self-directed behaviors. Wider implementation of this methodology may permit long-term analysis of personality using behavioral proxies for established personality traits, in particular on research investigating the effects of tourism and provisioning on personality

Analysis of Multi-Layer Immiscible Fluid Flow in a Microchannel

The development of microfluidics platforms in recent years has led to an increase in the number of applications involving the flow of multiple immiscible layers of viscous electrolyte fluids. In this study, numerical results as well as analytic equations for velocity and shear stress profiles were derived for N layers with known viscosities, assuming steady laminar flow in a microchannel driven by pressure and/or electro-static (Coulomb) forces. Numerical simulation results, using a commercial software package, match analytical results for fully-developed flow. Entrance flow effects with centered fluid-layer shrinking were studied as well. Specifically, cases with larger viscosities in the inner layers show a very good agreement with experimental correlations for the dimensionless entrance length as a function of inlet Reynolds number. However, significant deviations may occur for multilayer flows with smaller viscosities in the inner layers. A correlation was deduced for the two-layer electroosmotic flow and the pressure driven flow, both being more complex when compared with single-layer flows. The impact of using powerlaw fluids on resulting velocity profiles has also been explored and compared to Newtonian fluid flows. The present model readily allows for an exploration of the impact of design choices on velocity profiles, shear stress, and channel distribution in multilayer microchannel flows as a function of layered viscosity distribution and type of driving force

Public awareness of cancer in Britain: a population-based survey of adults

*_Objective:_* To assess public awareness of cancer warning signs, anticipated delay, and perceived barriers to seeking medical advice in the British population. &#xd;&#xa;Methods: We carried out a population-based survey using face-to-face, computer-assisted interviews to administer the Cancer Awareness Measure (CAM), a newly-developed, validated measure of cancer awareness. The sample included 2216 adults (970 male and 1246 female) recruited as part of the Office for National Statistics Opinions Survey using stratified probability sampling.&#xd;&#xa;&#xd;&#xa;*_Results:_* Awareness of cancer warning signs was low when open-ended (recall) questions were used and higher with closed (recognition) questions; but on either measure, awareness was lower in those who were male, younger, and from lower socioeconomic status (SES) groups or ethnic minorities. The most commonly endorsed barriers to help-seeking were difficulty making an appointment, worry about wasting the doctor&#x2019;s time and worry about what would be found. Emotional barriers were more prominent in lower SES groups and practical barriers (e.g. too busy) more prominent in higher SES groups. Anticipated delay was lower in ethnic minority and lower SES groups. In multivariate analysis, higher symptom awareness was associated with lower anticipated delay, and more barriers with greater anticipated delay.&#xd;&#xa;&#xd;&#xa;*_Conclusions:_* A combination of public education about symptoms and empowerment to seek medical advice, as well as support at primary care level, could enhance early presentation and improve cancer outcomes

Increasing condom use in heterosexual men: development of a theory-based interactive digital intervention

Increasing condom use to prevent sexually transmitted infections is a key public health goal. Interventions are more likely to be effective if they are theory- and evidence-based. The Behaviour Change Wheel (BCW) provides a framework for intervention development. To provide an example of how the BCW was used to develop an intervention to increase condom use in heterosexual men (the MenSS website), the steps of the BCW intervention development process were followed, incorporating evidence from the research literature and views of experts and the target population. Capability (e.g. knowledge) and motivation (e.g. beliefs about pleasure) were identified as important targets of the intervention. We devised ways to address each intervention target, including selecting interactive features and behaviour change techniques. The BCW provides a useful framework for integrating sources of evidence to inform intervention content and deciding which influences on behaviour to target

How Does Self-Control Promote Health Behaviors? A Multi-Behavior Test of Five Potential Pathways

Background Self-control is generally defined as the capacity to override impulses and is a robust predictor of health behaviors. This paper integrates trait, reasoned action, and habit approaches to develop and test a mechanistic account of how self-control influences health actions. Purpose We tested five potential pathways from self-control to behavior, termed the valuation, prioritization, habituation, translation, and inhibition routes. Methods At baseline, participants (N = 663 adults) completed survey measures of reasoned action approach variables and habits in relation to eight health behaviors and the Brief Self-Control Scale. Three months later, participants reported their behavior. Multi-level modeling was used to test pathways across behaviors. Results Supporting the valuation route, affective attitude, cognitive attitude, descriptive norms, and perceived behavioral control mediated the self-control-intention relation, and intentions and perceived behavioral control mediated the relationship between self-control and health behaviors. Self-control also predicted the priority accorded to different considerations during intention formation. Higher self-control was associated with stronger prediction by cognitive attitudes and perceived behavioral control and weaker prediction by habits and injunctive norms. Self-control predicted habit formation, and habits mediated the self-control-behavior relation. Finally, self-control was associated with the improved translation of intentions into health behaviors and with greater inhibition of affective and habitual influences. Findings for the different pathways were not moderated by whether approach (health-protective behaviors) or avoidance responses (health-risk behaviors) were at issue. Conclusions The present research offers new insights into why self-control promotes health behavior performance, and how deficits in self-control might be offset in future behavior-change interventions

Sustaining attendance at a mental health service: A randomized controlled trial

OBJECTIVE: A substantial proportion of psychotherapeutic treatments are prematurely terminated because the client discontinues attendance. Interventions have been developed to reduce premature termination, but these are only moderately effective and often place considerable burden on clients and services. This research evaluated a brief, low-cost self-regulation intervention (i.e., implementation intentions) designed to sustain attendance at a group psychoeducation program. METHOD: Clients (N = 82) who had been referred for a psychological intervention due to anxiety or depression were sent a questionnaire concerning their views of attendance. Participants were randomly assigned to form an implementation intention as part of the questionnaire or not (controls). Attendance was then monitored over the 5 scheduled sessions of an evidence-based psychoeducational intervention. RESULTS: Intention-to-treat analyses indicated that forming implementation intentions led to attendance at a greater number of sessions (M = 2.84 vs. 1.62), p < .01, and higher rates of completing the full course of treatment compared to controls (35% vs. 11%), p < .02. CONCLUSIONS: An intervention rooted in basic research on the psychology of action increased and sustained attendance at a mental health service. (PsycINFO Database Record (c) 2018 APA, all rights reserved)