4,070 research outputs found
Diverse Permian magmatism in the Tarim Block, NW China: Genetically linked to the Permian Tarim mantle plume?
Zircon UâPb ages and geochemical data are reported for the Piqiang oxide-bearing ultramficâmafic complex, the Bachu mafic dyke swarm, the Yingan and Kaipaizileike basalts and the Halajun A-type granites in the Tarim Block, Northwest China. The Piqiang complex and the Halajun A-type granites were emplaced at ca. 276 Ma and ca. 278 Ma, respectively. Together with previously reported geochronological data, the diverse intrusive and extrusive rocks in Tarim show a peak age at ca. 275 Ma. Elemental and Nd isotope geochemistry suggests that the spatially and temporally related Piqiang complex (including some dolerite dykes or stocks) and the Halajun A-type granites were formed via crystal fractionation/accumulation of a common plume-derived parental mafic magma (melting degree > 10%), coupled with variable extents of crustal contamination. Crystal fractionation/accumulation in one or several magma chambers resulted in the diversity of rocks types.The Bachu mafic dyke swarm shares a similar mantle source with the intrusive rocks in the PiqiangâHalajun area but with a relatively lower degree of partial melting (~ 5%). In contrast, the basalts were derived from a time-integrated, enriched lithospheric mantle source as suggested by their high-Ti, LREE- and LILE-enriched trace element signature and negative ΔNd(t) values (â 2.0 ~ â2.6). The synchronous yet diverse range of Permian igneous rocks in Tarim can best be accounted for by a Permian mantle plume, which is about 15 Ma earlier than the Emeishan plume in southwestern China.Research Highlights âș The ultramafic-mafic complex in Tarim gave a zircon UâPb age of 276 Ma. âș The A-type granites in Tarim gave a zircon UâPb age of ca. 278 Ma. âș The diverse Permian intrusive rocks originated from the sub-lithospheric mantle. âș The basalts originated from a time-integrated, enriched lithospheric mantle source. âș Both the intrusive and extrusive rocks are genetically related to a Permian mantle plume
Association of NEDA-4 With No Long-term Disability Progression in Multiple Sclerosis and Comparison With NEDA-3: A Systematic Review and Meta-analysis
Esclerosis mĂșltiple; Discapacidad; NEDA-4Esclerosi mĂșltiple; Discapacitat; NEDA-4Multiple sclerosis; Disability; NEDA-4Background and Objectives No evidence of disease activity (NEDA)-4 has been suggested as a treatment target for disease-modifying therapy (DMT) in relapsing-remitting multiple sclerosis (RRMS). However, the ability of NEDA-4 to discriminate long-term outcomes in MS and how its performance compares with NEDA-3 remain uncertain. We conducted a systematic review and meta-analysis to evaluate (1) the association between NEDA-4 and no long-term disability progression in MS and (2) the comparative performance of NEDA-3 and NEDA-4 in predicting no long-term disability progression.
Methods English-language abstracts and manuscripts were systematically searched in MEDLINE, Embase, and the Cochrane databases from January 2006 to November 2021 and reviewed independently by 2 investigators. We selected studies that assessed NEDA-4 at 1 or 2 years after DMT start and had at least 4 years of follow-up for determination of no confirmed disability progression. We conducted a meta-analysis using random-effects model to determine the pooled odds ratio (OR) for no disability progression with NEDA-4 vs EDA-4. For the comparative analysis, we selected studies that evaluated both NEDA-3 and NEDA-4 with at least 4 years of follow-up and examined the difference in the association of NEDA-3 and NEDA-4 with no disability progression.
Results Five studies of 1,000 patients (3 interferon beta and 2 fingolimod) met inclusion criteria for both objectives. The median duration of follow-up was 6 years (interquartile range: 4â6 years). The prevalence of NEDA-4 ranged from 4.2% to 13.9% on interferon beta therapy and 24.9% to 25.1% on fingolimod therapy. The pooled OR for no long-term confirmed disability progression with NEDA-4 vs EDA-4 was 2.14 (95% confidence interval: 1.36â3.37; I2 = 0). We did not observe any significant difference between NEDA-4 and NEDA-3 in the comparative analyses.
Discussion In patients with RRMS, NEDA-4 at 1â2 years was associated with 2 times higher odds of no long-term disability progression, at 6 years compared with EDA-4, but offered no advantage over NEDA-3
Phase diagram as a function of doping level and pressure in EuLaFeAs system
We establish the phase diagram of EuLaFeAs system as a
function of doping level x and the pressure by measuring the resistivity and
magnetic susceptibility. The pressure can suppress the spin density wave (SDW)
and structural transition very efficiently, while enhance the antiferromagnetic
(AFM) transition temperature T of Eu. The superconductivity coexists
with SDW order at the low pressure, while always coexists with the Eu
AFM order. The results suggests that Eu spin dynamics is disentangeld
with superconducting (SC) pairing taken place in the two-dimensional
\emph{Fe-As} plane, but it can strongly affect superconducting coherence along
c-axis
Enhanced Superconductivity by Rare-earth Metal-doping in Phenanthrene
We successfully synthesized La- and Sm-doped phenanthrene powder samples and
discovered superconductivity at around 6 K in them. The s are 6.1 K for LaPhenanthrene and 6.0 K for SmPhenanthrene, which are
enhanced by about 1 K and 0.5 K compared to those in Phenanthrene (=K
and Rb) and in Phenanthrene ( = Sr and Ba) superconductors
respectively. The superconductive shielding fractions for LaPhenanthrene and
SmPhenanthrene are 46.1%%^{3+}T_cT_{\rm c}^{-1}^{-1}A_3AAe_{1.5}Ae$ = Sr and Ba) superconductors.Comment: 5 pages, 5 figure
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