Negative Sm Research Articles

Direct observation of the magnetic spin component of samarium–iron-based laves compound by magnetic Compton scattering

The spin-polarized electron momentum distributions (magnetic Compton profiles: MCP's) of SmFe 1.86Al 0.14 along the [1 1 1] direction have been measured at 10 and 300 K using the magnetic Compton scattering technique. It is found that the orbital moment dominates the magnetization in this compound. A comparison with a theoretical profile support that the shape of the experimental MCP's is reproduced by a sum of positive Fe and negative Sm 4f spin components. A slight difference is observed in the shape of MCP between 10 and 300 K.

Geochemical and petrographic studies of oldhamite, diopside, and roedderite in enstatite meteorites

Abstract— In Qingzhen (EH3), oldhamite contains numerous types of inclusions and intergrows with other phases; but in equilibrated enstatite chondrites and aubrites, it usually occurs as individual grains. I suggest that oldhamite in unequilibrated enstatite chondrites (UECs) crystallized from a melt, probably during chondrule formation. Subsequent thermal metamorphism on the parent bodies further modified the oldhamite occurrences in enstatite chondrites. This suggestion is consistent with the results of melting experiments on UECs and aubrites and with the volatile element enrichments in this mineral.I analyzed minor and trace element abundances in diopside from two aubrites. These data and petrographic observations suggest that diopside formed by igneous crystallization.I report the first known occurrence of roedderite in an aubrite and its major, minor, and trace element concentrations. This mineral is rich in alkalis but is depleted in siderophile and refractory lithophile elements.A negative Sm anomaly was noted in albite from equilibrated enstatite chondrites and aubrites.

Discoid Lupus Erythematosus: Successful Treatment With Oral Methotrexate

We report an encouraging response to treatment with methotrexate in a single patient with severe discoid lupus erythematosus who did not respond to conventional therapy. <h3>Report of a Case.</h3> A 61-year-old white woman presented 7 years ago with a 39-year history of severe scarring discoid lupus erythematosus. Previous treatments included topical and intralesional steroid therapy and lowdose prednisone. Examination revealed numerous large erythematous infiltrated scaly plaques with focal areas of atrophy on the face (<b>Figure 1</b>). There was extensive scarring from previous lesions. Aside from arthralgia, there was no evidence of systemic lupus erythematosus. Initial laboratory investigations included a normal hemogram, an elevated sedimentation rate, normal renal function, negative rheumatoid factor, antinuclear antibodies, anti-DNA, and RNP and Sm antibodies. Complement studies were normal. Findings from a skin biopsy specimen were consistent with discoid lupus erythematosus. Direct immunofluorescence studies showed negative findings. Initial therapy consisted of chloroquine (250 mg, orally twice

Retrograde fluid infiltration in the high-grade Modum Complex South Norway: evidence for age, source and REE mobility

The high-grade metamorphic basement of the Modum Complex, South Norway,exhibits retrogradation and alteration due to late stage fluid infiltration.Extensive alteration zones of albite-and calcite-rich veining occur especiallywithin and around numerous metagabbros. The gabbros, intruded at 1224±15Ma, are now partly altered to amphibolites due to the subsequent high-grade metamorphism.Two generations of albite-rich rocks have been recognized: (1) a fine-grained, foliated type;(2) a coarse-grained, crosscutting type. Both types show a typical greenschist facies mineralassemblage; albite ± actinolite ± chlorite ± talc. The calcite veins/dykesrepresent a younger generation of veins than both albite-rich types. U−Pb data for spheneof type (1) yielded an age of 1080±3 Ma, determining a point on the retrogradeP-T-t path of the Modum Complex. Increasing albitisation of themetagabbros leads to a decrease in(143ND/144Nd)oand an increase in (87Sr/86)o.Albite- and calcite-rich samples show negative ɛNd and positive ɛSr, suggesting that fluids which interacted with the metagabbros originated from a crustal reservoir. The Nd and Sr isotopic data show disequilibrium at the microscale as well as at the macroscale. Negative Sm−Nd model ages of the albite-rich rocks demonstrate that rare-earth elements (REEs) were mobile and fractionated during albitisation.