Near-Infrared Dual-Modal Sensing of Force and Temperature in Total Knee Replacement Using Mechanoluminescent Phosphor of Sr3Sn2O7: Nd, Yb.

Knee replacement surgery confronts challenges including patient dissatisfaction and the necessity for secondary procedures. A key requirement lies in dual-modal measurement of force and temperature of artificial joints during postoperative monitoring. Here, a novel non-toxic near-infrared (NIR) phosphor Sr3Sn2O7:Nd, Yb, is designed to realize the dual-modal measurement. The strategy is to entail phonon-assisted upconversion luminescence (UCL) and trap-controlled mechanoluminescence (ML) in a single phosphor well within the NIR biological transmission window. The phosphor is embedded in medical bone cement forming a smart joint in total knee replacements illustrated as a proof-of-concept. The sensing device can be charged in vitro by a commercial X-ray source with a safe dose rate for ML, and excited by a low power 980 nm laser for UCL. It attains impressive force and temperature sensing capabilities, exhibiting a force resolution of 0.5% per 10 N, force detection threshold of 15 N, and a relative temperature sensitive of up to 1.3% K-1 at 309 K. The stability against humidity and thermal shock together with the robustness of the device are attested. This work introduces a novel methodological paradigm, paving the way for innovative research to enhance the functionality of artificial tissues and joints in living organisms.

Increased peripheral circulating inflammatory cells and plasma inflammatory markers in patients with variant angina.

BACKGROUND: Emerging data suggest that inflammation may play an important role in the pathogenesis of coronary artery disease. However, the relation of inflammatory status to coronary vasospasm has been less investigated in patients with variant angina (VA). PURPOSE: The aim of this study, therefore, was to determine peripheral circulating white blood cells as well as monocyte cells and plasma C-reactive protein (CRP) and interleukin-6 (IL-6) levels in patients with VA, and to compare patients with VA, stable coronary artery disease, and controls with angiographically normal coronary arteries. METHOD: Thirty-three consecutive patients with documented VA, 26 with stable coronary artery disease, and 22 normal controls (with angiographically normal coronary arteries) were involved in this study. The peripheral blood was taken, and white blood cells and monocyte cells were counted. The plasma concentrations of CRP and IL-6 were also evaluated by enzyme-linked immunosorbent assay (ELISA). RESULTS: The data showed that white blood cell counts and monocyte cell counts were significantly higher in patients of the VA group than in the other two groups (white blood cell counts: 7340+/-1893/mm vs. 6187+/-1748/mm vs. 5244+/-1532/mm, P<0.05, respectively; monocyte cell counts: 510+/-213/mm vs. 425+/-209/mm vs. 383+/-192/mm, P<0.05, respectively). Similarly, levels of plasma CRP and IL-6 were also significantly higher in patients of the VA group than in patients with stable coronary artery disease (CRP: 0.42+/-0.21 mg/l vs. 0.27+/-0.14 mg/l; IL-6: 10.4+/-1.0 pg/dl vs. 6.2+/-0.7 pg/dl, P<0.01, respectively), and patients with normal controls (CRP: 0.42+/-0.21 mg/l vs. 0.17+/-0.10 mg/l; IL-6: 10.4+/-1.0 pd/dl vs. 3.0+/-0.7 pg/dl, P<0.01, respectively). The multivariate analysis showed that CRP was the independent variable most strongly associated with VA. CONCLUSION: Taken together, these findings suggested that more chronic, severe inflammation might be involved in the pathogenesis of VA, manifested by increased counts of circulating inflammatory cells and elevated plasma levels of CRP and IL-6.