Search

Through this study, nanocomposite co-polymer was prepared by reaction between Pentarythrytol and phthalic anhydride. Infrared spectroscopy and AFM technique was used for the purpose of distinguishing the nanopolymer. Thus, the ability of the synthetic polymer to absorb the green malachite pigment present in aqueous solutions was found. It was found that the nano polymer had an average height of 5.26 nm. Therefore, three different temperatures were used (298 , 308 and 318 K(. Also Three concentrations of part units per million (1,3 and 5) of the nano polymer synthesized were used for the study. Through this study, it was found that the nano polymer is effective in removing green malachite from all aqueous solutions. [ABSTRACT FROM AUTHOR]

Ultrasound-mediated microbubble thrombolysis (UMT) was performed in a middle cerebral artery occlusion model in rats to evaluate possible effects upon brain infarct volume, apoptosis, IL-6 and TNF-alpha levels, and disruption of the blood-brain barrier (BBB). The results show that infarct volume was significantly reduced (p<0.04) in the microbubble + ultrasound (MB + US) group as compared to control animals. The levels of IL-6 and TNF-alpha concentrations, as markers of tissue damage, were not significantly different. In trypan blue treated animals, no additional BBB disruption was observed for the UMT group. Likewise, there was no increase in apoptotic cell death outside the infarction area in animals treated with MB + US. The results demonstrate that UMT does not have a harmful effect upon ischemic stroke in a middle cerebral artery occlusion model of the rat. The significant reduction in brain infarction following insonation with ultrasound and microbubbles suggests a novel neuroprotective effect in ischemic stroke. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

In human relationships, responsiveness--behaving in a sensitive manner that is supportive of another person's needs--plays a major role in any interaction that involves effective communication, caregiving, and social support. Perceiving one's partner as responsive has been tied to both personal and relationship well-being. In this work, we examine whether and how a robot's behavior can instill a sense of responsiveness, and the effects of a robot's perceived responsiveness on the human's perception of the robot. In an experimental between-subject study (n=34), a desktop nonanthropomorphic robot performed either positive or negative responsiveness behaviors across two modalities (simple gestures and written text) in response to participants' negative event disclosure. We found that perceived partner responsiveness, positive human-like traits, and robot attractiveness were higher in the positively responsive condition. This has design implications for interactive robots, in particular for robots in caregiving roles. [ABSTRACT FROM AUTHOR]

The object of this study was to evaluate the safety of large doses of microbubbles and ultrasound administered to the head of rabbits as if they were receiving acute stroke therapy of a similar nature. Materials and Methods: Female New Zealand White rabbits were used, N=24, in three groups 1] n=4 control (no treatment), 2] n=10 bubble control (ultrasound plus aspirin), and 3] n=10 target group (ultrasound plus aspirin plus MRX-815 microbubbles). Group 3 was infused with IV bubbles over 1 hour at 0.16cc/kg. Ultrasound was delivered to the dehaired side of the head during bubble infusion and for 1 additional hour at 0.8 W/cm2 20% pulsed wave. Rabbits survived for 22 to 24 hours, were imaged with computerized tomography and 3 Tesla magnetic resonance imaging including contrast studies, and sacrificed. Tetrazolium (TTC) and Hematoxylin and Eosin (H&E) sections were made for pathological examination. Results: All 24 animals showed absence of bleeding, endothelial damage, EKG abnormalities, stroke, blood-brain-barrier breakdown, or other acute abnormalities. CT and MRI showed no bleeding or signs of stroke, but two animals had mild hydrocephalus. The EKGs showed normal variation in QTc. Rabbit behavior was normal in all. Minimal chronic inflammation unrelated to the study was seen in 5. Two animals were excluded because of protocol violations and replaced during the study. Conclusion: The administered dose of microbubbles and ultrasound demonstrated no detrimental effects on the healthy rabbit animal model. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Microbubbles are currently used as ultrasound contrast agents. Their potential therapeutic applications are also under investigation. Some aspects of microbubble behavior upon ultrasound exposure in narrow tubes are discussed. It is shown experimentally that the threshold for bubble collapse, as recorded by broadband acoustic emission, is not only dependent on the applied pressure amplitude, but also on the tube size with an increase for smaller vessels. This result is interpreted in term of a simple mathematical model, based on the change of the resonance frequency and damping of a microbubble in small vessels. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]