8,035 research outputs found
Upper Pseudogap Phase: Magnetic Characterizations
It is proposed that the upper pseudogap phase (UPP) observed in the high-Tc
cuprates correspond to the formation of spin singlet pairing under the bosonic
resonating-valence-bond (RVB) description. We present a series of evidence in
support of such a scenario based on the calculated magnetic properties
including uniform spin susceptibility, spin-lattice and spin-echo relaxation
rates, which consistently show that strong spin correlations start to develop
upon entering the UPP, being enhanced around the momentum (\pi, \pi) while
suppressed around (0, 0). The phase diagram in the parameter space of doping
concentration, temperature, and external magnetic field, is obtained based on
the the bosonic RVB theory. In particular, the competition between the Zeeman
splitting and singlet pairing determines a simple relation between the
"critical" magnetic field, H_{PG}, and characteristic temperature scale, T0, of
the UPP. We also discuss the magnetic behavior in the lower pseudogap phase at
a temperature Tv lower than T0, which is characterized by the formation of
Cooper pair amplitude where the low-lying spin fluctuations get suppressed at
both (0, 0) and (\pi, \pi). Properties of the UPP involving charge channels
will be also briefly discussed.Comment: 11 pages, 5 figures, final version to appear in PR
Development of a Simple Multiplex Electrochemiluminescence (ECL) Assay for Screening Pre-Type 1 Diabetes and Multiple Relevant Autoimmune Diseases
The presence of islet autoantibodies (iAbs) is currently the most reliable biomarker for type 1 diabetes (T1D). The current “gold” standard radio-binding assays that measure four major iAbs to insulin, IAA, GAD65, IA-2A and ZnT8, are laborious and do not fit for large-scale screenings. Around 40% of patients with T1D develop other autoimmune diseases like celiac disease, autoimmune thyroid disease, and so on. It is highly recommended to screen these closely related autoimmune diseases during T1D screening; however, there is no method available. Recently, on the platform of extensively validated high-sensitive and high-specific electrochemiluminescence (ECL) assay, we developed a multiplex ECL assay to combine up to 10 autoantibody assays into one single well with 5 μl of blood sample. It not only allows us to combine multiple iAbs into one but also makes it possible to simultaneously screen T1D and other multiple autoimmune diseases, which in turn facilitates large-scale screenings in the general population
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