We report the novel near-infrared (NIR) photocatalysis of YF₃ : Yb³⁺ ,Tm³⁺ /TiO₂ core/shell nanoparticles. The core/shell nanoparticles show photocatalytic activity under the NIR irradiation. This study demonstrates that the NIR energy can be used as the driving source for photocatalysis besides the UV and visible energy.

Alzheimer disease (AD) is a neurodegenerative disorder of the central nervous system. The neuropathological hallmarks of AD include extracellular amyloid-containing plaques and intracellular neurofibrillary tangles.¹ The molecular events leading to the development of sporadic late-onset AD have not been defined. Advanced age is the largest AD risk factor and glucose/energy metabolism is decreased during aging.^2-7 Recent evidence strongly supports the hypothesis that type 2 diabetes mellitus (T2D) is also a risk factor for AD.^8-11 Moreover, recent evidence suggests that worsening in cerebral glucose metabolism is associated with progression of AD clinical dementia.^12-16

Muscle and bone are closely associated in both anatomy and function, but the mechanisms that coordinate their synergistic action remain poorly defined. Myostatin, a myokine secreted by muscles, has been shown to inhibit muscle growth, and the disruption of the myostatin gene has been reported to cause muscle hypertrophy and increase bone mass. Extracellular vesicle-exosomes that carry microRNA (miRNA), mRNA, and proteins are known to perform an important role in cell-cell communication. We hypothesized that myostatin may play a crucial role in muscle-bone interactions and may promote direct effects on osteocytes and on osteocyte-derived exosomal miRNAs, thereby indirectly influencing the function of other bone cells. We report herein that myostatin promotes expression of several bone regulators such as sclerostin (SOST), DKK1, and RANKL in cultured osteocytic (Ocy454) cells, concomitant with the suppression of miR-218 in both parent Ocy454 cells and derived exosomes. Exosomes produced by Ocy454 cells that had been pretreated with myostatin could be taken up by osteoblastic MC3T3 cells, resulting in a marked reduction of Runx2, a key regulator of osteoblastic differentiation, and in decreased osteoblastic differentiation via the down-regulation of the Wnt signaling pathway. Importantly, the inhibitory effect of myostatin-modified osteocytic exosomes on osteoblast differentiation is completely reversed by expression of exogenous miR-218, through a mechanism involving miR-218-mediated inhibition of SOST. Together, our findings indicate that myostatin directly influences osteocyte function and thereby inhibits osteoblastic differentiation, at least in part, through the suppression of osteocyte-derived exosomal miR-218, suggesting a novel mechanism in muscle-bone communication.

Optical temperature sensing characteristics based on the ultraviolet (UV) upconversion luminescence (UCL) of Gd³⁺ ions are reported here for the first time. Under 980 nm excitation, the temperature dependence five-photon UV UCL from the ⁶P_J and ⁶I_J levels of Gd³⁺ ions in NaLuF₄:Yb³⁺, Tm³⁺, Gd³⁺ microcrystals were investigated systematically. The fluorescence intensity ratios (FIR) of two pairs of thermally coupled levels (⁶P_5/2, ⁶P_7/2 and ⁶I_9/2, ⁶I_7/2) were studied as a function of temperature in a range of 298–523 K. The maximum sensor sensitivities were found to be about 0.0004 K⁻¹ (333 K) and 0.0029 K⁻¹ (298 K) by exploiting the UC emissions from the ⁶P_J and ⁶I_J levels, respectively. This suggests that the Gd³⁺-based UCL materials are promising prototypes for application as multi-mode probes for use in bio-separation, MRI imaging, optical thermometers, etc.