In this study, the Fiber-Metal Laminates (FMLs) containing glass fiber reinforced polypropylene (GFPP) and aluminum (Al) sheet were consolidated with Al foam cores for preparing the sandwich panels. ...The aim of this article is the comparison of the flexural properties of FML/Al foam sandwich panels bonded with various surface modification approaches (silane treatment and combination of silane treatment with polypropylene (PP) based film addition). The FML/foam sandwich systems were fabricated by laminating the components in a mould at 200 °C under 1.5 MPa pressure. The energy absorbtion capacities and flexural mechanical properties of the prepared sandwich systems were evaluated by mechanical tests. Experiments were performed on samples of varying foam thicknesses (8, 20 and 30 mm). The bonding among the sandwich components were achieved by various surface modification techniques. The Al sheet/Al foam sandwiches were also consolidated by bonding the components with an epoxy adhesive to reveal the effect of GFPP on the flexural performance of the sandwich structures.
Application of blast tests causes some problems to characterize the performance of panels due to the drastic conditions of explosive medium. Real test has high safety concerns and is not easily ...accessible because of its extra budget. Some approaches are needed for the preliminary predictions of dynamic characteristics of panels under blast loading conditions. In this study, the response of sandwiches under blast effect was evaluated by combining quasi-static experiments and computational blast test data. The primary aim is to relate the quasi-static panel analysis to dynamic blast load. Based on this idea, lightweight sandwich composites were subjected to quasi-static compression loading with a special test apparatus and the samples were assumed as single degree-of-freedom mass-spring systems to include dynamic effect. This approach provides a simpler way to simulate the blast loading over the surface of the panels and reveals the possible failure mechanisms without applying any explosives. Therefore the design of the panels can be revised by considering quasi-static test results. In this work, the peak deflections and survivabilities of sandwiches for various explosive weights were predicted based on the formulations reported in the literature. Major failure types were also identified and evaluated with respect to their thicknesses.
Background Intraductal papillary mucinous neoplasms (IPMN) are being increasingly recognized as important precursors to pancreatic adenocarcinoma. Elucidation of the genetic changes underlying IPMN ...carcinogenesis may improve the diagnosis and management of IPMN. We sought to determine whether different histologic subtypes of IPMN would exhibit different frequencies of specific genetic mutations. Study Design Patients with resected IPMN-associated invasive carcinoma (IPMN-INV) between 1997 and 2012 were reviewed. Areas of carcinoma, high-grade dysplasia, and low-grade dysplasia were micro-dissected from each pathologic specimen. Targeted, massively parallel sequencing was then performed on a panel of 275 genes (including KRAS , GNAS , and RNF43 ). Results Thirty-eight patients with resected IPMN-INV and sufficient tissue for micro-dissection were identified. Median follow-up was 2.6 years. Mutations in GNAS were more prevalent in colloid-type IPMN-INV than tubular-type IPMN-INV (89% vs 32% respectively; p = 0.0003). Conversely, KRAS mutations were more prevalent in tubular-type than colloid-type IPMN-INV (89% vs 52%, respectively; p = 0.01). For noninvasive IPMN subtypes, GNAS mutations were more prevalent in intestinal (74%) compared with pancreatobiliary (31%) and gastric (50%) subtypes (p = 0.02). The presence of these mutations did not vary according to the degree of dysplasia ( GNAS : invasive 61%, high-grade 59%, low-grade 53%; KRAS : invasive 71%, high-grade 62%, low-grade 74%), suggesting that mutations in these genes occur early in IPMN carcinogenesis. Conclusions Colloid carcinoma associated with IPMN and its intestinal-type preinvasive precursor are associated with high frequencies of GNAS mutations. The mutation profile of tubular carcinoma resembles that of conventional pancreatic adenocarcinoma. Preoperative determination of mutational status may assist with clinical treatment decisions.
Aluminum/glass-fiber-reinforced polypropylene (Al/GFPP) laminates were manufactured by using various surface pretreatment techniques. Adhesion at the composite/metal interface was achieved by a ...surface pretreatment of Al sheets with amino-based silane coupling agents, incorporation of a polyolefin-based adhesive film and modification with a PP-based film containing 20 wt.% of maleic-anhydride-modified polypropylene (PP-g-MA). In order to increase the effect of bonding between components of the laminates, the combination of silane treatment and the addition of the PP-based film was also investigated. The mechanical properties (shear, peel, and bending strengths) of adhesively bonded Al/GFPP laminates were examined to evaluate the effects of the surface treatments mentioned. It was revealed that the adhesion in the laminated Al/GFPP systems could be improved by the treatment of aluminum surface with an amino-based silane coupling agent. Judging from the results of peel and bending strength, with incorporation of polyolefin-based films, adhesion in the Al/GFPP laminates increased significantly. The modification of Al/GFPP interfaces with a PP-g-MA/PP layer led to the highest improvement in their adhesion properties. The combination of surface modification with silane and addition of PP-based films did not yield the high bending strength desired. This may be due to the insufficient bonding between silane groups and PP-based films.
ABSTRACT
We update the main physical and orbital properties of the transiting hot Saturn planet HAT-P-19 b, based on a global modelling of high-precision transit and occultation light curves, taken ...with ground-based and space telescopes, archive spectra and radial velocity measurements, brightness values from broad-band photometry, and Gaia parallax. We collected 65 light curves by amateur and professional observers, measured mid-transit times, and analysed their differences from calculated transit timings based on reference ephemeris information, which we update as a result. We have not found any periodicity in the residuals of a linear trend, which we attribute to the accumulation of uncertainties in the reference mid-transit time and the orbital period. We comment on the scenarios describing the formation and migration of this hot-Saturn type exoplanet with a bloated atmosphere yet a small core, although it is orbiting a metal-rich (Fe/H = 0.24 dex) host star. Finally, we review the planetary mass–radius, the orbital period–radius, and density, and the stellar metallicity–core mass diagrams, based on the parameters we derive for HAT-P-19 b and those of the other 70 transiting Saturn-mass planets from the NASA Exoplanet Archive.
Several factors are known to affect prognosis of acute leukemia such as age, high leukocyte count, cytogenetic abnormality, performance status and recurrent leukemia. We aimed to investigate the ...association between cell surface markers and prognostic determinants such as recurrence at 6 and 12 months and survival at 6, 12 and 18 months in acute leukemia patients.
A total of 142 patients, 101 with acute myeloid leukemia (AML) and 41 with B-cell acute lymphoblastic leukemia (B-ALL) were included. The effects of surface markers on survival and recurrence rates were evaluated retrospectively.
In AML patients, CD5+ and CD34+ immunophenotypes and in ALL patients cCD22+, CD34+ and CD49f + CD19+ immunophenotypes were positive prognostic indicators. In AML patients CD7 expression, and in ALL patients CD5+, CD7+ and CD117+ immunophenotypes and >90% CD45 expression were negative prognostic indicators.
This study demonstrates that flow cytometry, a common diagnostic tool in acute leukemia, may also have prognostic value in acute leukemia in the future.
The Kilodegree Extremely Little Telescope (KELT) project has been conducting a photometric survey of transiting planets orbiting bright stars for over 10 years. The KELT images have a pixel scale of ...∼23″ pixel−1-very similar to that of NASA's Transiting Exoplanet Survey Satellite (TESS)-as well as a large point-spread function, and the KELT reduction pipeline uses a weighted photometric aperture with radius 3′. At this angular scale, multiple stars are typically blended in the photometric apertures. In order to identify false positives and confirm transiting exoplanets, we have assembled a follow-up network (KELT-FUN) to conduct imaging with spatial resolution, cadence, and photometric precision higher than the KELT telescopes, as well as spectroscopic observations of the candidate host stars. The KELT-FUN team has followed-up over 1600 planet candidates since 2011, resulting in more than 20 planet discoveries. Excluding ∼450 false alarms of non-astrophysical origin (i.e., instrumental noise or systematics), we present an all-sky catalog of the 1128 bright stars (6 < V < 13) that show transit-like features in the KELT light curves, but which were subsequently determined to be astrophysical false positives (FPs) after photometric and/or spectroscopic follow-up observations. The KELT-FUN team continues to pursue KELT and other planet candidates and will eventually follow up certain classes of TESS candidates. The KELT FP catalog will help minimize the duplication of follow-up observations by current and future transit surveys such as TESS.
PDF
