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Wang, Bowen, Mengjia Peng,, Liheng Jiang,, Fei Fang,, Juan Wang,, Yan Li,, Ruichen Zhao,, and Yuliang Wang,. A Rare Case of High-Altitude Polycythemia Complicated by Spontaneous Splenic Rupture. High Alt Med Biol. 25:247–250, 2024.—High-altitude polycythemia, a condition characterized by an increase in red blood cellRBC mass, can occur after prolonged exposure to high altitudes. While several studies have explored the complications associated with high-altitude polycythemia, there is currently no literature available on spontaneous spleen rupture caused by high-altitude polycythemia. Here, we reported a case of acute abdominal pain and hemodynamic instability in a 36-year-old male who had been residing at high altitude for 6 years, without any recent history of trauma. Computed tomography imaging revealed significant fluid accumulation in the abdomen, and a tear of the splenic capsule was identified during the following laparotomy. Subsequent evaluations confirmed the presence of polycythemia secondary to prolonged high-altitude exposure as the underlying etiology. This case served as an important reminder that high-altitude polycythemia could lead to serious complications, such as spontaneous spleen rupture. Clinicians should be aware of this potential complication and consider it in the differential diagnosis of patients presenting with abdominal pain and hemodynamic instability in this population. [ABSTRACT FROM AUTHOR]

Silicon carbide particle-reinforced aluminum matrix (SiCp/Al) composites are significant lightweight metal matrix composites extensively utilized in precision instruments and aerospace sectors. Nevertheless, the inclusion of rigid SiC particles exacerbates tool wear in mechanical machining, resulting in a decline in the quality of surface finishes. This work undertakes a comprehensive investigation into the problem of tool wear in SiCp/Al composite materials throughout the machining process. Initially, a comprehensive investigation was conducted to analyze the effects of cutting velocity vc, feed per tooth fz, milling depth ap, and milling width ae on tool wear during high-speed milling under SCCO2-MQL (Supercritical Carbon Dioxide Minimum Quantity Lubrication) ultrasonic vibration conditions. The results show that under the condition of SCCO2-MQL ultrasonic vibration, proper control of milling parameters can significantly reduce tool wear, extend tool service life, improve machining quality, and effectively reduce blade breakage and spalling damage to the tool, reduce abrasive wear and adhesive wear, and thus significantly improve the durability of the tool. Furthermore, a prediction model for tool wear was developed by employing the orthogonal test method and multiple linear regression. The model's relevance and accuracy were confirmed using F-tests and t-tests. The results show that the model can effectively predict tool wear, among which cutting velocity vc and feed rate fz are the key parameters affecting the prediction accuracy. Finally, a genetic algorithm was used to optimize the milling parameters, and the optimal parameter combination (vc = 60.00 m/min, fz = 0.08 mm/z, ap = 0.20 mm) was determined, and the optimized milling parameters were tested. Empirical findings suggest that the careful selection of milling parameters can significantly mitigate tool wear, extend the lifespan of the tool, and enhance the quality of the surface. This work serves as a significant point of reference for the processing of SiCp/Al composite materials. [ABSTRACT FROM AUTHOR]

A series of Na(La1 − xEux)(WO4)2 (NLW) phosphors were directly generated without calcination and organic additive via reaction of the (La1 − xEux)(OH)SO4 template with Na2WO4 by hydrothermal reaction. The XRD results show that pure Na(La1 − xEux)(WO4)2 can be obtained by the reaction at 150 °C for 24 h or at 200 °C for 2 h under the molar ratio of WO42−/ Ln3+ = 5. The NaLa(WO4)2 has a tetragonal structure in I41/a space group, and has lattice parameters of a = b = 5.332 Å, c = 11.731 Å. The FT-IR results show that the SO42− and hydroxyl vibrations of the template were hardly observed in the product and confirmed that phase conversion is complete. The UV-vis analysis yield bandgap values of 4.07 and 3.94 eV for NaLa(WO4)2 and Na(La0.95Eu0.05)(WO4)2 respectively. Photoluminescence excitation (PLE) studies found two distinct strong excitation peaks at ~ 395 nm and ~ 465 nm, with the former slightly stronger and both significantly stronger than other excitation peaks/bands. Under 395 nm excitation, the phosphors exhibited the strongest red emission at 614 nm (5D0→7F2 transition of Eu3+). The optimal Eu3+ concentration was found to be as high as 25% due to the layered structure of NLW phosphor and well isolated Eu3+ activator by [WO4] polyhedron. An evaluation and comparison with other phosphors were conducted to assess the performance of optical temperature sensing. It was discovered that the NLW phosphor cannot be employed as a probe for optical thermometry via fluorescence intensity ratio (FIR) mode due to similar intensity loss rates with increasing temperatures for different emission peaks. The NLW was demonstrated to be well capable of temperature sensing via fluorescence lifetime (FL) mode. Fluorescence decay analysis found that higher measurement temperature shortened the lifetime of the 614 nm main emission, and the lifetime decreased in liner mode. The maximum absolute sensitivity (SA) and relative sensitivity (SR) are 43.0 × 10− 4 K− 1 (298–498 K) and 144 × 10− 4 K− 1(498 K), respectively. [ABSTRACT FROM AUTHOR]