344 research outputs found

    Cyclin D1 and p16 expression in recurrent nasopharyngeal carcinoma

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    Abstract Background Cyclin D1 and p16 are involved in the regulation of G1 checkpoint and may play an important role in the tumorigenesis of nasopharyngeal carcinoma (NPC). Previous studies have examined the level of expression of cyclin D1 and p16 in primary untreated NPC but no such information is available for recurrent NPC. We set out in this study to examine the expression level of cyclin D1 and p16 in recurrent NPC that have failed previous treatment with radiation +/- chemotherapy. Patients and methods A total of 42 patients underwent salvage nasopharyngectomy from 1984 to 2001 for recurrent NPC after treatment failure with radiation +/- chemotherapy. Twenty-seven pathologic specimens were available for immunohistochemical study using antibodies against cyclin D1 and p16. Results Positive expression of cyclin D1 was observed in 7 of 27 recurrent NPC specimens (26%) while positive p16 expression was seen in only 1 of 27 recurrent NPC (4%). Conclusion While the level of expression of cyclin D1 in recurrent NPC was similar to that of previously untreated head and neck cancer, the level of p16 expression in recurrent NPC samples was much lower than that reported for previously untreated cancer. The finding that almost all (96%) of the recurrent NPC lack expression of p16 suggested that loss of p16 may confer a survival advantage by making cancer cells more resistant to conventional treatment with radiation +/- chemotherapy. Further research is warranted to investigate the clinical use of p16 both as a prognostic marker and as a potential therapeutic target

    OH-bearing planar defects in olivine produced by the breakdown of Ti-rich humite minerals from Dabie Shan (China)

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    The partial breakdown of Ti-chondrodite and Ti-clinohumite during exhumation from ultra-high pressure to amphibolite facies conditions in garnet-pyroxenites from Dabie Shan (China) produces coronas of olivine coexisting with ilmenite blebs. Fourier transform infrared (FTIR) spectra of this newly formed olivine exhibit absorption bands in the hydroxyl-stretching region. Two intense peaks were observed at 3,564 and 3,394 cm-1, identical in energy to peaks in Ti-clinohumite. Transmission electron microscopy (TEM) of the same olivine domains revealed the presence of a complex (001) planar intergrowth. These interlayers have a 1.35 nm repeat distance, which is characteristic of clinohumite. Such interlayers are also enriched in Ti with respect to the adjacent olivine as shown by energy dispersive spectrometry. The combined evidence from FTIR spectroscopy and TEM indicates that OH is incorporated along Ti-clinohumite planar defects. This study provides evidence that the nominally anhydrous phase olivine may contain OH as a humite-type defect beyond the breakdown of the hydrous humite minerals and confirms earlier suggestions that Ti plays a key role in OH incorporation in mantle olivine. We suggest that olivine containing Ti-clinohumite defects is an important phase for water transport in subduction zones and for the storage of water in cold subcontinental mantle. However, these defects are unlikely to be stable in hotter parts of the oceanic mantle such as where basaltic magmas are generated

    Recurrence of pulmonary intravascular bronchoalveolar tumor with mediastinal metastasis 20 years later

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    SummaryPulmonary intravascular bronchoalveolar tumor (IVBAT) also recognized as pulmonary epithelioid hemangioendothelioma, is a rare malignant vascular tumor of unknown etiology. IVBAT is a tumor of multicentric origin and the lungs are rarely involved, with only about 60 cases of pulmonary IVBAT described in the literature. The prognosis is unpredictable, with life expectancy ranging from 1 to 15 years. We report an unusual case of pulmonary IVBAT that recurred in the lung with metastasis to the mediastinum

    Helicity, polarization, and Riemann-Silberstein vortices

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    Riemann-Silberstein (RS) vortices have been defined as surfaces in spacetime where the complex form of a free electromagnetic field given by F=E+iB is null (F.F=0), and they can indeed be interpreted as the collective history swept out by moving vortex lines of the field. Formally, the nullity condition is similar to the definition of "C-lines" associated with a monochromatic electric or magnetic field, which are curves in space where the polarization ellipses degenerate to circles. However, it was noted that RS vortices of monochromatic fields generally oscillate at optical frequencies and are therefore unobservable while electric and magnetic C-lines are steady. Here I show that under the additional assumption of having definite helicity, RS vortices are not only steady but they coincide with both sets of C-lines, electric and magnetic. The two concepts therefore become one for waves of definite frequency and helicity. Since the definition of RS vortices is relativistically invariant while that of C-lines is not, it may be useful to regard the vortices as a wideband generalization of C-lines for waves of definite helicity.Comment: 5 pages, no figures. Submitted to J of Optics A, special issue on Singular Optics; minor changes from v.

    Overview of Boundary Layer Transition Research in Support of Orbiter Return To Flight

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    A predictive tool for estimating the onset of boundary layer transition resulting from damage to and/or repair of the thermal protection system was developed in support of Shuttle Return to Flight. The boundary layer transition tool is part of a suite of tools that analyze the aerothermodynamic environment to the local thermal protection system to allow informed disposition of damage for making recommendations to fly as is or to repair. Using mission specific trajectory information and details of each damage site or repair, the expected time (and thus Mach number) at transition onset is predicted to help define the aerothermodynamic environment to use in the subsequent thermal and stress analysis of the local thermal protection system and structure. The boundary layer transition criteria utilized for the tool was developed from ground-based measurements to account for the effect of both protuberances and cavities and has been calibrated against select flight data. Computed local boundary layer edge conditions were used to correlate the results, specifically the momentum thickness Reynolds number over the edge Mach number and the boundary layer thickness. For the initial Return to Flight mission, STS-114, empirical curve coefficients of 27, 100, and 900 were selected to predict transition onset for protuberances based on height, and cavities based on depth and length, respectively

    The Photometric Period and Variability of the Cataclysmic Variable V849 Herculis (PG 1633+115)

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    We report time-resolved photometry of the cataclysmic variable V849 Her, and measure a period of 0.1414 \pm 0.0030 days (3.394 \pm 0.072 hours). We also present photometry taken over several weeks in 2010 and 2011, as well as light curves from 1995 to 2011 by the American Association of Variable Star Observers. The spectra, absolute magnitude derived from infrared magnitudes, and variability all suggest that V849 Her is a nova-like variable. The shallow (0.5-magnitude) low states we observe resemble the erratic low states of the VY Sculptoris stars, although they may recur quasi-periodically over an average cycle of 12.462 \pm 0.074 days.Comment: 18 pages, 9 figures, accepted for publication in New Astronom

    Perspectives in quality: designing the WHO Surgical Safety Checklist

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    The World Health Organization's Patient Safety Programme created an initiative to improve the safety of surgery around the world. In order to accomplish this goal the programme team developed a checklist with items that could and, if at all possible, should be practised in all settings where surgery takes place. There is little guidance in the literature regarding methods for creating a medical checklist. The airline industry, however, has more than 70 years of experience in developing and using checklists. The authors of the WHO Surgical Safety Checklist drew lessons from the aviation experience to create a safety tool that supports essential clinical practice. In order to inform the methodology for development of future checklists in health care, we review how we applied lessons learned from the aviation experience in checklist development to the development of the Surgical Safety Checklist and also discuss the differences that exist between aviation and medicine that impact the use of checklists in health car

    BMQ

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    BMQ: Boston Medical Quarterly was published from 1950-1966 by the Boston University School of Medicine and the Massachusetts Memorial Hospitals

    1972 Research Progress Reports, Fruit and Vegetable Processing and Food Technology

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    Evaluation of tomato cultivars / W. A. Gould, James Black, Louise Howiler, Shirley Perryman, and Stanley Z. Berry -- Effects of food additives on the quality of canned tomatoes / Wilbur A. Gould, John Mount, Jacquelyn Gould, Louise Howiler, and James Black -- Effect of storage temperature on shelf life of ascorbic acid fortified tomato juice / Gerald A. Pope and Wilbur A. Gould -- Survey of waste disposal practices of Ohio tomato processors / J. R. Geisman -- Evaluation of snap bean varieties for processing / Wilbur A. Gould, Jacquelyn Gould and Roberta Topits -- The effect of variety, size, and fermentation temperature on the quality attributes of cucumber pickles / Gary Flinn and Wilbur A. Gould -- Progress report on frozen corn-on-the-cob / James W. Swinehart and Wilbur A. Gould -- Progress report on cabbage lipids / Andrew C. Peng -- Effect of soybean flour on quality and protein content in the manufacture of doughnuts / Mohamed I. Mahmoud and Wilbur A. Goul

    Computation of the Power Spectrum in Chaotic 1/4λϕ41/4 \lambda \phi^4 Inflation

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    The phase-integral approximation devised by Fr\"oman and Fr\"oman, is used for computing cosmological perturbations in the quartic chaotic inflationary model. The phase-integral formulas for the scalar power spectrum are explicitly obtained up to fifth order of the phase-integral approximation. As in previous reports [1-3], we point out that the accuracy of the phase-integral approximation compares favorably with the numerical results and those obtained using the slow-roll and uniform approximation methods.Comment: Accepted in JCAP (15 pages, 5 figures). arXiv admin note: substantial text overlap with arXiv:0904.429
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