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REBa 2 Cu 3 O 7−δ (REBCO, RE = rare earth elements) cryomagnets have considerable potential for magnetic applications due to their high field trapping capacities over 10 T at temperatures below 77 K. The controlled nucleation of REBCO crystals for attaining superior performance decisively relies on the seeding strategy related to seed material and seeding assembly. Recently, buffer-assisted seeding approaches have been developed for reliable growth, in which buffer-crystals are by-products and discarded after splitting off from main crystals as ceramic waste though containing certain expensive matters such as RE, Ag and Pt. Here, for the first time, we succeeded in utilizing YBCO and NdBCO/Ag buffer-crystals as seeds for producing REBCO crystals under maximum processing temperatures of 1015 ℃ and 1053 ℃, respectively. YBCO specimens were characterized by differential scanning calorimetry and secondary ion mass spectrometry. It was verified that the buffer-crystal was 5.5 K higher than the normal-crystal in peritectic temperature (T p). Furthermore, the highly distributed Mg element was identified in the upper middle part of buffer-crystal, which was diffused from the Mg-involved NdBCO seed in previous fabrication. It is the Mg existence that enhanced T p of the buffer-crystal and made it highly thermal stable in seeding YBCO growth. In contrast to expensive commercial film-seeds and multistep home-prepared crystal-seeds, buffer-crystal-seeds distinctively have cost- and time-saving benefits. Most importantly, the current success adds new value of reusability to buffer-assisted seeding approaches towards a sustainable fabrication of REBCO cryomagnets. [ABSTRACT FROM AUTHOR]

To precisely prevent stroke, we evaluated three platelet function tests and their associations with clinical outcomes in ischemic stroke patients. On-treatment platelet reactivity of acute minor stroke patients taking aspirin plus clopidogrel was tested by light transmittance aggregometry (LTA), thromboelastography (TEG) and platelet function analyzer (PFA). Mann-Whitney U tests and receiver operating characteristic (ROC) curve analysis were used to assess their associations with recurrent events and clinical outcome prediction. 127 acute minor stroke patients were stringently selected and followed for 13 months. Eight patients (6.3%) self-reported the recurrence and 13 (10.2%) patients self-reported bleeding. Recurrent patients displayed significantly higher on-treatment platelet reactivity when measured with LTA (p = 0.030) and PFA (p < 0.001). Further ROC analysis demonstrated that LTA and PFA had modest-to-fair ability to predict stroke recurrence (LTA: area under the curve [AUC], 0.765; 95% CI, 0.584–0.945, PFA: AUC, 0.832; 95% CI, 0.658–1.000). However, TEG (measured by the platelet inhibition rate) could not detect the difference between recurrent patients and non-recurrent patients (p = 0.515) and predict recurrent events (AUC, 0.569; 95% CI, 0.368–0.770). None of the tests were associated with bleeding except for PFA (p < 0.001), with AUC of PFA reaching 0.772 (0.726–0.818). Of the three tests assessed, the predictive accuracies of PFA and LTA were satisfying for aspirin secondary prevention, while TEG's performance was poor. Only PFA could provide accurate prognostic information for bleeding. [ABSTRACT FROM AUTHOR]

Background: Impaired cerebrovascular reactivity (CVR) plays an important role in the pathophysiology of white matter hyperintensities (WMHs). The pathogenesis of CVR in the development of WMH‐related cognitive impairment (CI) remains poorly understood. Purpose: To detect the CVR status in WMH subjects with/without CI by using a resting‐state blood oxygenation level‐dependent (BOLD) approach and to explore the mediating relationships among CVR, WMH, and cognitive level. Study Type: Prospective. Subjects: Subjects with moderate to severe WMH (with CI [WMH‐CI], n = 68; without CI [WMH‐no‐CI, n = 63) as well as normal controls (NCs, n = 87). Field Strength/Sequence: 3.0T with gradient‐recalled echoplanar imaging and 3D fluid‐attenuated inversion recovery. Assessment: The CVR, WMH volume, and cognitive level were assessed. The CVR map was derived using BOLD signal obtained from resting‐state functional MRI data. Statistical Tests: CVR maps were compared among the three groups. Partial correlation analyses were performed to correlate impaired CVR with WMH volume and cognitive test scores. Mediation analysis was conducted to determine whether WMH acted as a mediating factor between CVR and cognitive function. Results: Compared with the NC group, both WMH groups showed reduced CVR in the left hemisphere (P < 0.05). The WMH‐CI group showed further decreased CVR in the left frontal area, when compared with the WMH‐no‐CI group (P < 0.05). In the WMH‐CI group, the lower CVR in left frontal area was a strong indicator of poor performance on general cognition (r = 0.311), executive function (r = 0.362), and information processing speed (r = 0.399) (all P < 0.05). Periventricular WMH (PWMH) volume mediated these correlations, the β and 95% bootstrap confidence intervals were (0.5097, [0.1498,1.1385]), (−0.4081, [−1.0256,‐0.1363]), and (−0.5576, [−1.4666,‐0.1538]), respectively. Data Conclusion: WMH‐CI subjects showed a greater reduction of CVR derived from a resting‐state BOLD approach in the left frontal area than WMH‐no‐CI subjects. Cognition was highly dependent on the integrity of cerebrovascular reactivity and mediated by PWMH burden. Level of Evidence: 4 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

Highlights: [•] Large sized Ag-free SmBCO bulk with high performance was prepared in air. [•] An YBCO buffered NdBCO thin film on MgO substrate was used to guarantee a proper maximum processing temperature (T max). [•] We introduced Ba-rich Sm2Ba4Cu2O y (Sm242) phase into this work to ensure a high T c (over 94K). [•] Sm2Ba4CuBiO z (Sm2411) phase was employed to further reinforce J c (about 68KA/cm2). [Copyright &y& Elsevier]