A review on magneto-optical ceramics for Faraday isolators

As a promising magneto-optical (MO) material applied in Faraday isolators, magneto-optical ceramics possess excellent comprehensive properties and have attracted much attention these years. Herein, we review the fabrication and properties of magneto-optical ceramics including garnet, sesquioxide, and A2B2O7 ceramics. Some of the ceramics have been proved to possess applicable performance, while further studies are still needed for most of the magneto-optical ceramics. Aiming at the application for isolators, the research status, existing problems, and development trends of magneto-optical ceramics are shown and discussed in this review

Terbium (III) Oxide (Tb2O3) Transparent Ceramics by Two-Step Sintering from Precipitated Powder

As a result of preliminary air calcination and subsequent reduction in a flowing NH3 atmosphere of the precursor from the liquid precipitation method for the first time, pure-phase Tb2O3 powder with an average particle size of 135 nm was prepared. The Tb2O3 magneto-optical transparent ceramics with the average grain size of 1.3 μm were successfully fabricated by vacuum pre-sintering and hot isostatic pressing post-treatment from the as-synthesized Tb2O3 powder. In-line transmittance values of Tb2O3 ceramics reach 70.3% at 633 nm, 78.1% at 1064 nm, and 79.4% at 1400 nm, respectively. Thanks to the high intrinsic concentration of Tb3+, Tb2O3 ceramics present high Verdet constants of −427.3 and −123.7 rad·T−1·m−1 at 633 and 1064 nm, which are about 3.1 and 3.4 times higher than those of commercial Tb3Ga5O12 crystals, respectively. Due to the excellent magneto-optical properties, Tb2O3 ceramics are promising candidates for the development of Faraday isolator toward compaction used in visible and near-infrared bands

Screening preoperative peptide biomarkers for predicting postoperative myocardial infarction after coronary artery bypass grafting.

Postoperative myocardial infarction (PMI) is one of the most serious complications of cardiac surgeries. No preoperative biomarker is currently available for predicting PMI after cardiac surgeries. In the present study, we used a phage display peptide library to screen potential preoperative peptide biomarkers for predicting PMI after coronary artery bypass grafting (CABG) surgery. Twenty patients who developed PMI after CABG and 20 age-, sex-, and body mass index-matched patients without PMI after CABG were enrolled as a discovery cohort. Another 50 patients who developed PMI after CABG and 50 randomly selected patients without PMI after CABG were enrolled as a validation cohort to validate the potential peptide biomarkers identified in the discovery cohort. Fifty randomly selected healthy volunteers were also enrolled in the validation phase as a healthy control group. In the discovery/screening phase, 17 out of 20 randomly selected phage clones exhibited specific reaction with purified sera IgG from the PMI group, among which 11 came from the same phage clone with inserted peptide sequence GVIMVIAVSCVF (named PMI-1). In the validation phase, phage ELISA showed that serum IgG from 90% of patients in the PMI group had a positive reaction with PMI-1; in contrast, only 14% and 6% of patients in the non-PMI group and the healthy control group had a positive reaction with PMI-1, respectively. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the PMI-1 phage clone to preoperatively identify patients who would develop PMI after CABG were 90.0%, 86.0%, 86.5, 89.5% and 88.0%, respectively. The absorbance value of the PMI-1 phage clone showed statistically significant correlation with the peak postoperative serum cardiac troponin I level (r = 0.349, p = 0.012) in the PMI group. In conclusion, we for the first time identified a mimic peptide (PMI-1) with high validity in preoperative prediction of PMI after CABG

Fabrication of Dy2O3 Transparent Ceramics by Vacuum Sintering Using Precipitated Powders

As a kind of promising material for a Faraday isolator used in the visible and near infrared range, Dy2O3 transparent ceramics were prepared by vacuum sintering from the nano-powders synthesized by the liquid precipitation method using ammonium hydrogen carbonate as precipitant with no sintering aids. The synthesized precursor was calcinated at 950 °C–1150 °C for 4 h in air. The influences of the calcination temperature on the morphologies and phase composition of Dy2O3 powders were characterized. It is found that the Dy2O3 powder calcinated at 1000 °C for 4 h is superior for the fabrication of Dy2O3 ceramics. The Dy2O3 transparent ceramic sample prepared by vacuum sintering at 1850 °C for 10 h, and subsequently with air annealing at 1400 °C for 10 h, from the 1000 °C-calcined Dy2O3 powders, presents the best optical quality. The values of in-line transmittance of the optimal ceramic specimen with the thickness of 1.0 mm are 75.3% at 2000 nm and 67.9% at 633 nm. The Verdet constant of Dy2O3 ceramics was measured to be −325.3 ± 1.9 rad/(T·m) at 633 nm, about 2.4 times larger than that of TGG (Tb3Ga5O12) single crystals

Terbium (III) Oxide (Tb₂O₃) Transparent Ceramics by Two-Step Sintering from Precipitated Powder

As a result of preliminary air calcination and subsequent reduction in a flowing NH3 atmosphere of the precursor from the liquid precipitation method for the first time, pure-phase Tb2O3 powder with an average particle size of 135 nm was prepared. The Tb2O3 magneto-optical transparent ceramics with the average grain size of 1.3 μm were successfully fabricated by vacuum pre-sintering and hot isostatic pressing post-treatment from the as-synthesized Tb2O3 powder. In-line transmittance values of Tb2O3 ceramics reach 70.3% at 633 nm, 78.1% at 1064 nm, and 79.4% at 1400 nm, respectively. Thanks to the high intrinsic concentration of Tb3+, Tb2O3 ceramics present high Verdet constants of −427.3 and −123.7 rad·T−1·m−1 at 633 and 1064 nm, which are about 3.1 and 3.4 times higher than those of commercial Tb3Ga5O12 crystals, respectively. Due to the excellent magneto-optical properties, Tb2O3 ceramics are promising candidates for the development of Faraday isolator toward compaction used in visible and near-infrared bands

Serum cardiac troponin I (cTnI) levels after coronary artery bypass grafting (CABG) in the discovery and validation cohorts of patients.

<p>Serum cTnI levels were determined at baseline (within 72 hours before CABG) and at 1, 6, 12 and 24 hours after CABG in (A) the discovery (n = 20 each for the PMI and the non-PMI groups) and (B) the validation (n = 50 each for the PMI and the non-PMI groups) cohorts of patients. PMI, postoperative myocardial infarction.</p

Baseline general characteristics of the discovery and validation cohorts of patients.

<p><b>Note</b>: Continuous variable values were expressed as Mean±SD. Categorical variables were expressed as n(%). BMI, body mass index; LVEF, left ventricular ejection fraction; PMI, postoperative myocardial infarction.</p

Inserted DNA sequence in positive peptide phage clones.

<p>After 3 rounds of biopanning, 20 peptide phage clones were randomly picked and reacted with sera IgG from patients with PMI after coronary artery bypass grafting. Phage clones were considered positive when their absorbance values in phage ELISA were above the cutoff value (0.494), which was set to 2 times of the absorbance value of the negative control (NC, black bar) at 450 nm. C1, C2, C5, C7, C10, C12, C13, C15, C16, C18 and C19 positive phage clones (green bars) had the same inserted DNA sequence 5′-GGC GTA ATC ATG GTC ATA GCT GTT TCC TGT GTG AAA-3′. The corresponding peptide sequence was GVIMVIAVSCVF (named PMI-1). C4, C8, C11 and C20 positive phage clones (blue bars) had the same inserted DNA sequence 5′-GGG TCC TTA GTG ATG TTG GTG TTC GGT TAC ATG GGC-3′. The corresponding peptide sequence was GSLVMLVFGYMG (named PMI-2). The negative phage clones were shown in red bars. The two single positive phage clones were shown in white bars.</p