551 research outputs found
Pyoderma gangrenosum: a presenting sign of myelodysplastic syndrome in undiagnosed Fanconi anemia
A 26-year-old man with a history of congenital bilateral microtia, unilateral renal agenesis, left aural atresia, and right external auditory canal occlusion admitted for right rib cartilage graft harvest and left ear re-construction. Following surgery, an ulceration with violaceous borders and a yellow fibrinous base unresponsive to broad-spectrum antibiotics developed at the harvest site. The wound was expanding and not responsive to systemic broad-spectrum antibiotics. Biopsy revealed a dense dermal infiltrate of neutrophils with negative tissue cultures consistent with pyoderma gangrenosum (PG). He was treated with systemic, intralesional, and topical steroids, as well as doxycycline. Three weeks after the diagnosis of PG, he was found to have persistent anemia and leukopenia. Bone marrow aspiration analysis was consistent with hypocellular myelodysplastic syndrome and genetic testing was consistent with Fanconi anemia. There is a well-known association of PG with hematological disorders. Fanconi anemia is a rare genetic hematologic disorder with congenital defects leading to bone marrow failure and malignancy in long-standing disease. In our patient, we consider his development of PG a paraneoplastic sign associated with the onset of his hypocellular myelodysplastic syndrome
Leave Vacant or Rent: The Optimal Decision for Absentee Home Sellers
Home-sellers may not occupy their property when listed for sale. While previous research has analyzed the effect of a vacancy on the sales price of residential properties, no research to date has quantified the economic benefits and costs of renting vis-à-vis leaving a property vacant while listed for sale. Renting a property will produce revenue but perhaps at the cost of a lower sale price and/or longer time on the market. This paper employs data on 55,202 homes sold in the Las Vegas, Nevada area to determine if renting a property increases or decreases the wealth position of home sellers. The results of an empirical test of the model are used to quantify the wealth effect. The findings indicate that renting the property produces a significant reduction in the home seller’s wealth position.
Application of vascular aquatic plants for pollution removal, energy and food production in a biological system
Vascular aquatic plants such as water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxeroides) (Mart.) Griesb., when utilized in a controlled biological system (including a regular program of harvesting to achieve maximum growth and pollution removal efficiency), may represent a remarkably efficient and inexpensive filtration and disposal system for toxic materials and sewage released into waters near urban and industrial areas. The harvested and processed plant materials are sources of energy, fertilizer, animal feed, and human food. Such a system has industrial, municipal, and agricultural applications
Neutron Scattering to Characterize Cu/Mg(Li) Destabilized Hydrogen Storage Materials
Cu-Li-Mg-(H,D) was studied as an example of destabilizer of the Ti-(H,D) system. A Cu-Li-Mg alloy was prepared resulting in the formation of a system with 60.5 at% of CuLi0.08Mg1.92, 23.9 at% of CuMg 2 and 15.6 at% of Cu2Mg. Titanium was added to a fraction of this mixture so that 68.2 at% (47.3 wt%) of the final mixture was Ti. The mixture was ground and kept at 200 °C/473 K for 7h under H2 or 9h under D2 at P = 34 bar. Under those conditions, neutron powder diffraction shows the formation of TiD2, as well as of the deuteride of CuLi0.08Mg1.92. Similarly inelastic neutron scattering shows that at 10 K TiH2 is present in the sample, together with the hydride of CuLi0.08Mg1.92. Interestingly, at 10 K TiH 2 is very clearly detected and at 300 K TiH2 is still clearly present as indicated by the neutron vibrational spectrum, but CuLi 0.08Mg1.92-H is not detected anymore. These results indicate that Ti(H,D)2 is possibly formed by diffusion of hydrogen from the Cu-Li-Mg-(H,D) alloys. This is an intriguing result since TiH 2 is normally synthesized from the metal at T > 400°C/673 K (and most commonly at T ∼ 700 °C/973 K). In the presence of CuLi 0.08Mg1.92, TiH2 forms at a temperature that is 300 - 400 K lower than that needed to synthesize it just from the elements
Reliable First-Principles Alloy Thermodynamics via Truncated Cluster Expansions
In alloys cluster expansions (CE) are increasingly used to combine
first-principles electronic-structure and Monte Carlo methods to predict
thermodynamic properties. As a basis-set expansion in terms of lattice
geometrical clusters and effective cluster interactions, the CE is exact if
infinite, but is tractable only if truncated. Yet until now a truncation
procedure was not well-defined and did not guarantee a reliable truncated CE.
We present an optimal truncation procedure for CE basis sets that provides
reliable thermodynamics. We then exemplify its importance in NiV, where the
CE has failed unpredictably, and now show agreement to a range of measured
values, predict new low-energy structures, and explain the cause of previous
failures.Comment: 4 pages, 2 figure
Search for a Solution of the Pioneer Anomaly
In 1972 and 1973 the Pioneer 10 and 11 missions were launched. They were the
first to explore the outer solar system and achieved stunning breakthroughs in
deep-space exploration. But beginning in about 1980 an unmodeled force of \sim
8 \times 10^{-8} cm/s^2, directed approximately towards the Sun, appeared in
the tracking data. It later was unambiguously verified as being in the data and
not an artifact. The cause remains unknown (although radiant heat remains a
likely origin). With time more and more effort has gone into understanding this
anomaly (and also possibly related effects). We review the situation and
describe ongoing programs to resolve the issue.Comment: 24 pages 8 figure
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