2,140 research outputs found

    Characterization of mild whole-body hyperthermia protocols using human breast, ovarian, and colon tumors grown in severe combined immunodeficient mice.

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    OBJECTIVE: We have shown that one treatment of fever-like whole body hyperthermia (WBH) on mice bearing human breast tumors results in a tumor growth delay. Our goal was to repeat this study in mice bearing human ovarian or colon tumors. We further evaluated this WBH protocol by performing multiple and interrupted WBH treatments. METHODS: Human tumors were grown in severe combined immunodeficient (SCID) mice. For WBH, core body temperatures were maintained at 39.8+/-0.2 degrees C for 6-8 hours. Multiple treatments were given 6-7 days apart. Interrupted WBH consisted of three 2-hour heatings, 15 minutes apart. Tumor growth time (TGT) was the number of days to grow 1.5 or 2 times in volume. RESULTS: For WBH-treated ovarian tumors, TGT was 12+/-1.2d, compared with 5.0+/-0.1d for untreated mice (P < 0.05). For colon tumors with one WBH treatment TGT was 4.4+/-1.1d. Two and three treatments had TGTs of 9+/-2.3d and 8+/-1.6d. For the untreated tumors, TGT was 2+/-0.7d (P < 0.01 for one, two, and three treatments). Histological examination indicated that one and two treatments were associated with cellular damage within the tumors. With a slower growing colon tumor, the TGT was 24+/-3.3d with three WBH treatments, compared with 14+/-1.8d for controls (P < 0.01). The TGT of breast tumors treated with interrupted WBH was not significantly different than the noninterrupted, with TGT of 7.3+/-0.8d and 6.2+/-1.0d, respectively. CONCLUSIONS: These data illustrate that WBH causes a tumor growth delay in mice bearing human ovarian and colon tumors. This response is enhanced with a second treatment of WBH. Interrupted and noninterrupted WBH give comparable anti-tumor results. We will continue to evaluate WBH in various animal models to optimize its potential for clinical administration and maximize the anti-tumor response

    Relative and Absolute Mappings for Rotating Remote 3D Objects on Multi-Touch Tabletops

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    The use of human fingers as an object selection and manipulation tool has raised significant challenges when interacting with direct-touch tabletop displays. This is particularly an issue when manipulating remote objects in 3D environments as finger presses can obscure objects at a distance that are rendered very small. Techniques to support remote manipulation either provide absolute mappings between finger presses and object transformation or rely on tools that support relative mappings t o selected objects. This paper explores techniques to manipulate remote 3D objects on direct-touch tabletops using absolute and relative mapping modes. A user study was conducted to compare absolute and relative mappings in support of a rotation task. Overall results did not show a statistically significant difference between these two mapping modes on both task completion time and the number of touches. However, the absolute mapping mode was found to be less efficient than the relative mapping mode when rotating a small object. Also participants preferred relative mapping for small objects. Four mapping techniques were then compared for perceived ease of use and learnability. Touchpad, voodoo doll and telescope techniques were found to be comparable for manipulating remote objects in a 3D scene. A flying camera technique was considered too complex and required increased effort by participants. Participants preferred an absolute mapping technique augmented to support small object manipulation, e.g. the voodoo doll technique

    HS Hya about to turn off its eclipses

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    Aims: We aim to perform the first long-term analysis of the system HS Hya. Methods: We performed an analysis of the long-term evolution of the light curves of the detached eclipsing system HS Hya. Collecting all available photometric data since its discovery, the light curves were analyzed with a special focus on the evolution of system's inclination. Results: We find that the system undergoes a rapid change of inclination. Since its discovery until today the system's inclination changed by more than 15 deg. The shape of the light curve changes, and now the eclipses are almost undetectable. The third distant component of the system is causing the precession of the close orbit, and the nodal period is about 631 yr. Conclusions: New precise observations are desperately needed, preferably this year, because the amplitude of variations is decreasing rapidly every year. We know only 10 such systems on the whole sky at present.Comment: 4 pages, 3 figures, published in 2012A&A...542L..23

    Fetal Neuroprotective Strategies: Therapeutic Agents and Their Underlying Synaptic Pathways

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    Synaptic signaling is integral for proper brain function. During fetal development, exposure to inflammation or mild hypoxic-ischemic insult may lead to synaptic changes and neurological damage that impairs future brain function. Preterm neonates are most susceptible to these deleterious outcomes. Evaluating clinically used and novel fetal neuroprotective measures is essential for expanding treatment options to mitigate the short and long-term consequences of fetal brain injury. Magnesium sulfate is a clinical fetal neuroprotective agent utilized in cases of imminent preterm birth. By blocking N-methyl-D-aspartate receptors, magnesium sulfate reduces glutamatergic signaling, which alters calcium influx, leading to a decrease in excitotoxicity. Emerging evidence suggests that melatonin and N-acetyl-L-cysteine (NAC) may also serve as novel putative fetal neuroprotective candidates. Melatonin has important anti-inflammatory and antioxidant properties and is a known mediator of synaptic plasticity and neuronal generation. While NAC acts as an antioxidant and a precursor to glutathione, it also modulates the glutamate system. Glutamate excitotoxicity and dysregulation can induce perinatal preterm brain injury through damage to maturing oligodendrocytes and neurons. The improved drug efficacy and delivery of the dendrimer-bound NAC conjugate provides an opportunity for enhanced pharmacological intervention. Here, we review recent literature on the synaptic pathways underlying these therapeutic strategies, discuss the current gaps in knowledge, and propose future directions for the field of fetal neuroprotective agents

    Classification of vascular anomalies

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