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The adenosine diphosphate (ADP) receptor P2RY12 (purinergic receptor P2Y, G protein coupled, 12) plays a critical role in platelet aggregation, and P2RY12 inhibitors are used clinically to prevent cardiac and cerebral thrombotic events. Extracellular ADP has also been shown to increase osteoclast (OC) activity, but the role of P2RY12 in OC biology is unknown. Here, we examined the role of mouse P2RY12 in OC function. Mice lacking P2ry12 had decreased OC activity and were partially protected from age-associated bone loss. P2ry12/ OCs exhibited intact differentiation markers, but diminished resorptive function. Extracellular ADP enhanced OC adhesion and resorptive activity of WT, but not [P2ry12.sup.-/-], OCs. In platelets, ADP stimulation of P2RY12 resulted in GTPase Ras-related protein (RAP 1) activation and subsequent [α.sub.IIb][β.sub.3] integrin activation. Likewise, we found that ADP stimulation induced RAP1 activation in WT and integrin [β.sub.3] gene knockout ([Itgb3.sup.-/-]) OCs, but its effects were substantially blunted in [P2ry12.sup.-/-] OCs. In vivo, [P2ry12.sup.-/-] mice were partially protected from pathologic bone loss associated with serum transfer arthritis, tumor growth in bone, and ovariectomy-induced osteoporosis: all conditions associated with increased extracellular ADP. Finally, mice treated with the clinical inhibitor of P2RY12, clopidogrel, were protected from pathologic osteolysis. These results demonstrate that P2RY12 is the primary ADP receptor in OCs and suggest that P2RY12 inhibition is a potential therapeutic target for pathologic bone loss., Introduction Osteoclasts (0Cs) are multinudeated myeloid lineage cells that are the principal source of bone resorptive activity (1). Enhanced OC activity, bone loss, and fractures are associated with rheumatoid arthritis, [...]

The effects of pearlite on the initiation and propagation of localized corrosion in Q370qD and Q370qE weathering steels under a simulated marine environment were examined by scanning Kelvin probe force microscopy, scanning electron microscope, scanning vibrating electrode technique and X-ray diffraction. Pearlite was uniformly distributed in Q370qD steel, whereas it displayed a banded distribution with a relatively higher proportion in Q370qE steel. Proeutectoid ferrite around pearlite and lamellar ferrite inside pearlite preferentially dissolved as the anode of micro-galvanic couples, and lamellar cementite acted as the cathode. The coarser interlamellar spacing and higher pearlite content enhanced the micro-galvanic effects in the microstructure and promoted localized corrosion propagation rate. The corrosion rate of Q370qE steel was higher than that of Q370qD steel. With the extension of corrosion time, corrosion products preferentially accumulated on the pearlite phase. The banded pearlite microstructure caused surface defects in rust layers. Uniformly distributed pearlite microstructure was more conducive to the formation of a dense rust layer. [ABSTRACT FROM AUTHOR]

The development of high-performance, cost-effectiveness bifunctional catalysts synthesized by convenient strategy has aroused great attention toward water splitting reaction. In this work, the nanoporous catalyst with a sandwich structure, constructed of amorphous alloy matrix and porous layers, was fabricated by one-step dealloying of Ni25Y60Al15 metallic glass for 15 min in citric acid solution. This catalyst, consisting of the hybrid of NiY and NiO, exhibited a uniform three-dimension porous structure with a pore size of about 5–20 nm. The electrochemical measurements indicated that the nanoporous hybrid possesses excellent catalytic performances toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline medium. The overpotentials at 50 mA/cm2 are about 0.45 V and 0.52 V for HER and OER, respectively, with low Tafel slopes of 43.9 mV/dec and 116.8 mV/dec. The enhanced electro-catalysis mainly contributed to its large electrochemically active surface area and low interfacial charge transfer resistance. As such, this high-performance, low-cost, and bifunctional nanoporous catalyst has broad application prospects in electrocatalytic water splitting. [ABSTRACT FROM AUTHOR]

This paper provides a detailed overview of active impulsive noise control (AINC) technology of α-stable distribution noise. The second-order moment of the non-Gaussian impulsive noise does not exist, so the adaptive algorithms based on second-order statistics would lead to poor noise reduction performance. On account of this defect, a series of AINC algorithms have been proposed over the past 25 years. In this paper, we briefly classified the AINC algorithms into the classic algorithms and the expanded algorithms depending on different criteria, and both the classic AINC algorithms and the expanded AINC algorithms are further divided. Afterward, we introduced the principles and characteristics of different AINC algorithms and listed the weights update formulas of those algorithms. Finally, the computational complexity comparisons of common AINC algorithms and further recommendations are given, and a brief review about the experimental testing of AINC systems is provided in order to assist related scholars to carry out AINC researches more conveniently. [ABSTRACT FROM AUTHOR]

The influence of Nb in the transformation behavior of ultra‐high‐strength pearlitic steels is studied. The phase transition temperature is measured by thermal simulation device, and the continuous cooling transformation curve is established. Results show that with addition of Nb, the equilibrium transformation temperature of the test steel increases, and both size of the original austenite, pearlite colonies and pearlite lamellar spacing are refined. Pearlitic transformation mechanism has changed by the addition of Nb through the interaction of solid solution and precipitation. Nb microalloy delays the beginning and ending point of pearlite transformation when the cooling rate is greater than 1.00 and 0.10 °C s−1, respectively. In contrast, the transformation point is advanced when the cooling rate is less than 0.50 and 0.05 °C s−1. This variation is mainly due to the morphology and distribution of Nb‐containing precipitates at different cooling rates. [ABSTRACT FROM AUTHOR]

To overcome the negative contrast limitations, and to improve the sensitivity of the magnetic resonance signals, the mesoporous silica coated Fe/Mn multilayered nanowires (NWs) were used as a T1–T2 dual‐mode contrast agents (CAs). The single component Fe and Mn NWs, and Fe/Mn multilayer NWs were synthesized by electrodeposition in the homemade anodic aluminum oxide (AAO) templates with the aperture of about 30 nm. The structural characterization and morphology of single component and multisegmented NWs was done by X‐ray diffraction and transmission electron microscopy. The elemental composition of Fe/Mn multilayerd NWs was confirmed by energy‐dispersive X‐ray and energy‐dispersive spectrometer. Vibrating sample magnetometer was used to test the magnetic properties, and 1.5 T magnetic resonance imaging (MRI) scanner was used to measure the relaxation efficiency. Importantly, the MRI study indicated that the Fe/Mn multilayer NWs showed a significant T1–T2 imaging effect, and have longitudinal relaxivity (r1) value, that is, 1.25 ± 0.0329 × 10−4 μM−1 s−1 and transverse relaxivity (r2), that is, 5.13 ± 0.123 × 10−4 μM−1 s−1, which was two times of r1 value (0.654 ± 0.00899 × 10−4 μM−1 s−1) of Mn NWs, and r2 value (2.96 ± 0.0415 × 10−4 μM−1 s−1) of Fe NWs. Hence, Fe/Mn multilayer NWs have potential to be used as T1–T2 dual‐mode CAs. [ABSTRACT FROM AUTHOR]