704 research outputs found

    X-ray diffraction from shock-loaded polycrystals

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    X-ray diffraction was demonstrated from shock-compressed polycrystalline metal on nanosecond time scales. Laser ablation was used to induce shock waves in polycrystalline foils of Be, 25 to 125 microns thick. A second laser pulse was used to generate a plasma x-ray source by irradiation of a Ti foil. The x-ray source was collimated to produce a beam of controllable diameter, and the beam was directed at the Be sample. X-rays were diffracted from the sample, and detected using films and x-ray streak cameras. The diffraction angle was observed to change with shock pressure. The diffraction angles were consistent with the uniaxial (elastic) and isotropic (plastic) compressions expected for the loading conditions used. Polycrystalline diffraction will be used to measure the response of the crystal lattice to high shock pressures and through phase changes

    A Remote Laser System for Material Characterization at High Temperatures

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    For many years, new techniques have been developed to overcome the problems involved with the generation and detection of ultrasound in materials at high temperature [1,2]. A non-contacting technique is described using lasers to generate and detect ultrasound and which can be used to study the variation in acoustic velocity as a function of temperature. Results are presented for the change in longitudinal velocity (vâ„“) with increasing temperature in five polycrystalline materials, namely Dural, aluminum, AISI-310 stainless steel, iron and graphite

    The tumor suppressor protein OPCML potentiates anti-EGFR and anti-HER2 targeted therapy in HER2-positive ovarian and breast cancer.

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    OPCML is a tumor suppressor gene that is frequently inactivated in ovarian cancer and many other cancers by somatic methylation. We have previously shown that OPCML exerts its suppressor function by negatively regulating a spectrum of receptor tyrosine kinases (RTKs), such as ErbB2/HER2, FGFR1 and EphA2, thus attenuating their related downstream signaling. The physical interaction of OPCML with this defined group of RTKs is a prerequisite for their downregulation. Overexpression/gene amplification of EGFR and HER2 is a frequent event in multiple cancers including ovarian and breast cancers. Molecular therapeutics against EGFR/HER2 or EGFR only, such as lapatinib and erlotinib respectively, were developed to target these receptors but resistance often occurs in relapsing cancers. Here we show that, though OPCML interacts only with HER2 and not with EGFR, the interaction of OPCML with HER2 disrupts the formation of the HER2-EGFR heterodimer and this translates into a better response to both lapatinib and erlotinib in HER2-expressing ovarian and breast cancer cell lines. Also, we show that high OPCML expression is associated with better response to lapatinib therapy in breast cancer patients and better survival in HER2-overexpressing ovarian cancer patients, suggesting that OPCML co-therapy could be a valuable sensitizing approach to RTK inhibitors

    NASA's Understanding of Risk in Apollo and Shuttle

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    Mathematical risk analysis was used in Apollo, but it gave unacceptably pessimistic resultsand was discontinued. Shuttle was designed without using risk analysis, under the assumptionthat good engineering would make it very safe. This approach led to an unnecessarily riskydesign, which directly led to the Shuttle tragedies. Although the Challenger disaster wasdirectly due to a mistaken launch decision, it might have been avoided by a safer design. Theultimate cause of the Shuttle tragedies was the Apollo era decision to abandon risk analysis

    The Role of Race and Economic Characteristics in the Presentation and Survival of Patients With Surgically Resected Non-Small Cell Lung Cancer

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    Background: Little is understood regarding the inter-relation between economic, marital, and racial/ethnic differences in presentation and survival of surgically resected lung cancer patients. Our investigation will assess these differences in addition to known therapeutic, patient, and histopathologic factors. Methods: A retrospective review of the Surveillance Epidemiology and End Reporting database was conducted through the years 2007-2012. The population was split into nine different ethnic groups. Population differences were assessed via chi-square testing. Multivariable analysis (MVA) were used to detect overall survival (OS) differences in the total surgical population (TS, N = 35,689) in an ear (T1-T2 \u3c 4 cm N0) surgical population [early-stage resectable (ESR), N = 17,931]. Lung cancer-specific survival (LCSS) was assessed in the ESR. Results: In the TS population, as compared to Whites, Blacks, and Hispanics presented with younger age, more adenocarcinomas, lower rates of marriage, lower rates of insurance, less stage I tumors, and had less nodes examined, but their type of surgical procedures and OS/LCSS were the same. MVA demonstrated that lower OS and LCSS were associated with males, single/divorced/widowed partnership, lower income (TS only), and Medicaid insurance. MVA also found that Blacks and Hispanics had a similar OS/LCSS to Whites and that all ethnic groups were associated with a similar or better outcomes. The 90-day mortality and positive nodes were correlated with not having insurance and not being married, but they were not associated with ethnicity. Conclusion: In TS and ESR groups, OS was not different in the two largest ethnic groups (Black and Hispanic) as compared to Whites, but was related to single/widowed/divorced status, Medicaid insurance, and income (TS group only). Nodal positivity was associated with patients who did not have a married partner or insurance suggesting that these factors may impact disease biology. Economic and psychosocial variables may play a role in survival of ear lung cancer in addition to standard histopathologic and treatment variables

    Diminished Neural and Cognitive Responses to Facial Expressions of Disgust in Patients with Psoriasis: A Functional Magnetic Resonance Imaging Study

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    Psoriasis produces significant psychosocial disability; however, little is understood about the neurocognitive mechanisms that mediate the adverse consequences of the social stigma associated with visible skin lesions, such as disgusted facial expressions of others. Both the feeling of disgust and the observation of disgust in others are known to activate the insula cortex. We investigated whether the social impact of psoriasis is associated with altered cognitive processing of disgust using (i) a covert recognition of faces task conducted using functional magnetic resonance imaging (fMRI) and (ii) the facial expression recognition task (FERT), a decision-making task, conducted outside the scanner to assess the ability to recognize overtly different intensities of disgust. Thirteen right-handed male patients with psoriasis and 13 age-matched male controls were included. In the fMRI study, psoriasis patients had significantly (P<0.005) smaller signal responses to disgusted faces in the bilateral insular cortex compared with healthy controls. These data were corroborated by FERT, in that patients were less able than controls to identify all intensities of disgust tested. We hypothesize that patients with psoriasis, in this case male patients, develop a coping mechanism to protect them from stressful emotional responses by blocking the processing of disgusted facial expressions

    Tutor and teacher timescapes : lessons from a home-school partnership

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    A partnership project was developed in which parents volunteered to support teachersin training years 1-3 children in computer skills at a primary school in a small, lowsocio-economic community. This article identifies the ways teachers and the &lsquo;tutors&rsquo;(as the volunteers were called) understood the value of the project. &lsquo;Being a teacher&rsquo;and &lsquo;being a volunteer&rsquo; were structured by different forms of social engagement,which in turn influenced the ways individuals were able to work with each other incollaborative processes. We argue that the discursive practices encoded in homeschool-community partnership rhetoric represent ruling-class ways of organising andnetworking that may be incompatible with those of people from low socio-economicbackgrounds. When such volunteers work in schools their attendance may be sporadicand short-term whereas teachers would like &lsquo;reliable&rsquo; ongoing commitment. Thismismatch wrought of teachers&rsquo; and volunteers&rsquo; differing everyday realities needs to beunderstood before useful models for partnerships in disadvantaged communities maybe realised.<br /
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