Compact In Situ Electrochemical NMR with Wireless and Anti-interference Strategy in Multiscenario Applications.

The integration of electrochemistry with nuclear magnetic resonance (NMR) spectroscopy recently offers a powerful approach to understanding oxidative metabolism, detecting reactive intermediates, and predicting biological activities. This combination is particularly effective as electrochemical methods provide excellent mimics of metabolic processes, while NMR spectroscopy offers precise chemical analysis. NMR is already widely utilized in the quality control of pharmaceuticals, foods, and additives and in metabolomic studies. However, the introduction of additional and external connections into the magnet has posed challenges, leading to signal deterioration and limitations in routine measurements. Herein, we report an anti-interference compact in situ electrochemical NMR system (AICISENS). Through a wireless strategy, the compact design allows for the independent and stable operation of electrochemical NMR components with effective interference isolation. Thus, it opens an avenue toward easy integration into in situ platforms, applicable not only to laboratory settings but also to fieldwork. The operability, reliability, and versatility were validated with a series of biomimetic assessments, including measurements of microbial electrochemical systems, functional foods, and simulated drug metabolisms. The robust performance of AICISENS demonstrates its high potential as a powerful analytical tool across diverse applications.

Optical power degradation mechanisms in 271†nm AlGaN-based deep ultraviolet light-emitting diodes.

The degradation of AlGaN-based UVC LEDs under constant temperature and constant current stress for up to 500 hrs was analyzed in this work. During each degradation stage, the two-dimensional (2D) thermal distributions, I-V curves, optical powers, combining with focused ion beam and scanning electron microscope (FIB/SEM), were thoroughly tested and analyzed the properties and failure mechanisms of UVC LEDs. The results show that: 1) the opto-electrical characteristics measured before/during stress indicate that the increased leakage current and the generation of stress-induced defects increase the non-radiative recombination in the early stress stage, resulting in a decrease in optical power; 2) the increase of temperature caused by the deterioration of the Cr/Al layer of p-metal after 48 hrs of stress aggravates the optical power in UVC LEDs. The 2D thermal distribution in conjunction with FIB/SEM provide a fast and visual way to precisely locate and analyze the failure mechanisms of UVC LEDs.

[Short-term effects of citrate on markers of bone metabolism in Chinese blood donor volunteers].

This study was purposed to investigate the short-term effects of citrate administration on bone metabolism in the healthy blood donor volunteers. A crossover, placebo-controlled trial were conducted on 22 healthy blood donor volunteers. The volunteers received either a standardized infusion of citrate at 1.5 mg/(kg.min) or the equal volume of placebo normal saline, were washout for 2-3 weeks. During washout serial blood samples were collected and analyzed for bone biochemical markers and electrolytes, such as bone formation marker osteocalcin (OC), bone resorption marker carboxyterminal telopeptide of type I collagen (CTX), intact parathyroid hormone ((i)PTH), ionized calcium ((i)Ca(2+)) and phosphorus (P(i)). Serial urine samples were collected and analyzed for Ca(2+), P(i) and creatinine concentration. The results showed that compared with placebo group, infusion of citrate increased serum levels of OC and CTX (p < 0.0001). The greatest increase of OC and CTX levels occurred at the completion of the intervention. The increment of CTX was higher than OC (p = 0.02), and the OC/CTX ratio decreased (p < 0.01). Infusion of citrate also induced profound increase in serum (i)PTH level (p < 0.0001) and urinary calcium excretion (p < 0.0001), and decrease in serum (i)Ca(2+) (p < 0.0001) and P(i) (p < 0.01) levels. The decrease of (i)Ca(2+) level in female was higher than that in male (p = 0.007), but the changes of (i)PTH, OC, and CTX levels showed no differences between female and male. Changes of OC and CTX levels were closely related to each other (r = 0.56, p < 0.0001) and changes of both markers were negatively correlated with the change of serum (i)Ca(2+) concentration during the citrate intervention(r(OC) = -0.44, r(CTX) = -0.44, p < 0.0001). Increased levels of (i)PTH showed positively correlation with OC (r = 0.34, p = 0.02) and borderline correlation with CTX (r = 0.29, p = 0.06) in male. No such relationship was observed in female. All bone markers and electrolyte levels returned to baseline within 24 hours. It is concluded that the citrate load at the dose as a single platelet apheresis results in profound increase of bone turnover, which is characterized by a short-term increase of bone resorption and excretion of calcium. The possible effect of citrate on bone mass of long-term frequent platelet apheresis donor is worth concerning.