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Lead (Pb) is a heavy metal highly toxic to human health in the environment. The aim of this study was to investigate the mechanism of Pb impact on the quiescence of hematopoietic stem cells (HSC). WT C57BL/6 (B6) mice treated with 1250 ppm Pb via drinking water for 8 weeks had increased the quiescence of HSC in the bone marrow (BM), which was caused by the suppressed activation of the Wnt3a/β-catenin signaling. Mechanically, a synergistic action of Pb and IFNγ on BM-resident macrophages (BM-Mφ) reduced their surface expression of CD70, which thereby dampened the Wnt3a/β-catenin signaling to suppress the proliferation of HSC in mice. In addition, a joint action of Pb and IFNγ also suppressed the expression of CD70 on human Mφ to impair the Wnt3a/β-catenin signaling and reduce the proliferation of human HSC purified from umbilical cord blood of healthy donors. Moreover, correlation analyses showed that the blood Pb concentration was or tended to be positively associated with the quiescence of HSC, and was or tended to be negatively associated with the activation of the Wnt3a/β-catenin signaling in HSC in human subjects occupationally exposed to Pb. Collectively, these data indicate that an occupationally relevant level of Pb exposure suppresses the Wnt3a/β-catenin signaling to increase the quiescence of HSC via reducing the expression of CD70 on BM-Mφ in both mice and humans. [ABSTRACT FROM AUTHOR]

Due to the different sensitivities of the 2E and 4T2 energy levels of Cr3+ to the local environment, Cr3+-doped fluorescent materials appear as excellent candidates for highly sensitive temperature sensing based on luminescence intensity ratio technology. However, a way to broaden the strict Boltzmann temperature measuring range is rarely reported. In this work, through Al3+ alloying strategy, a series of SrGa12−xAlxO19:0.5%Cr3+(x = 0, 2, 4, and 6) solid-solution phosphors were synthesized. Remarkably, the introduction of Al3+ can play a role in regulating the crystal field around Cr3+ and the symmetry of [Ga/AlO6] octahedron, realizing the synchronous tuning of 2E and 4T2 energy levels when the temperature changes in a wide range, achieving the purpose of increasing the intensity difference of 2E → 4A2 and 4T2 → 4A2 transitions, so as to extend the temperature sensing range. Among all samples, SrGa6Al6O19:0.5%Cr3+ showed the widest temperature measuring range from 130 K to 423 K with Sa of 0.0066 K−1 and Sr of 1% K−1@130 K. This work proposed a feasible way to extend the temperature sensing range for transition metal-doped LIR-mode thermometers. [ABSTRACT FROM AUTHOR]

In this paper, a multi-period buffer space hedging coordination between a building contractor (BC) and a logistics provider (LP) is investigated. In order to facilitate the application of the construction lead-time hedging (CLTH) strategy, adopted by the BC, extra buffer space needs to be reserved at LP's intermediate warehouse for contingency usage. This strategy is defined as 'buffer space hedging (BSH)' and it increases the pressure of LP on involving extra storage and maintenance cost. Two coordination mechanisms are adopted for solving this BSH problem. One scheme is by introducing a cost-sharing term. A Nash game model is studied to find the individual optimal decisions. Another scheme is a cooperative game model with proper side-payments. We show that adjusting the BSH amount for each review period benefits the supply chain. Both coordination mechanisms enable a win–win outcome. Especially, if system resources are sufficient, the cooperative game outperforms the Nash game. Numerical experiments further demonstrate that the benefit of the proposed model is more significant under the case with lower unit enlarging/rearrangement cost, higher tardiness penalty and unpredictable and uncontrollable construction process-determined assembled and installed prefabs. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the flow dynamics and temperature characteristics under different reservoir operation scenarios and weather conditions in the river-reservoir system, which can be used to set scientific guidelines for river management and conservation planning strategies. The calibrated three-dimensional model provided simulated unsteady water surface elevation, temperature, velocity and discharge at different layers (depths) in different locations. A series of operation scenarios were modeled to understand and quantify formation, propagation, and disappearance of density currents that are resulted from combinations of daily repeated large release (DRLR) of different durations and solar heating. DRLRs (140 m3/s) with longer durations pushed the bottom cold water further downstream and maintained the bottom water temperature cooler. Variations of weather conditions (e.g., drops of air temperature and solar radiation) directly controled variations of bottom-layer water temperature. The daily drop rate of bottom temperature was related to the rate and duration of air temperature drop. Under the practice for the water turbines running at downstream, it clearly showed the shocking withdrawal and stopping effect from the downstream operation. The velocity for the whole cross-section were almost increased with same magnitude of about 0.1 m/s at GOUS and JML.

Perovskites based on CsPbX3 (X = Cl, Br, I) have promising applications in solar cells, light-emitting diodes, and photodetectors. In this paper, the phase stability of inorganic metal halide perovskite CsPbCl3 under hydrostatic pressure and anion substitution is studied using density functional theory (DFT), and this modification is explained by the interaction of the octahedrons and transformation of the bond-orbital coupling. In addition, two space groups, P4/mbm and Amm2, which are stable under stress, are subjected to anion substitution; then, the structural stability and band gap change of CsPbCl3−yXy (X = Br, I; y = 0, 1, 2, 3) are analyzed after applying stress; finally, the electronic structures and optical properties of the six most stable components are presented. The effect of stress and anions on the components' optoelectronic properties is closely linked with the crystal's structural alteration mechanism. These results show that stress and anion modulation can significantly change the optoelectronic properties of materials, which make these materials have broad application prospects. Furthermore, stress can be used as an effective tool for screening the most stable material structure. [ABSTRACT FROM AUTHOR]

The key to developing laser-driven solid-state lighting lies in high-performance color converters, which must be thermally robust under the high-power density excitation of a laser. Phosphor-in-glass (PiG) films are considered as a kind of promising color converter for laser lighting, but the poor thermal dissipation of the glass matrix will cause large thermal quenching of the PiG films and hence low luminous flux of lighting sources. In this work, Al2O3 particles, acting as a heat transfer medium, are introduced into the La3Si6N11:Ce3+ (LSN:Ce3+) PiG film to form a composite color converter for realizing high-brightness laser lighting. By optimizing the ratio of glass frits to Al2O3 as well as the film thickness, the Al2O3–LSN:Ce3+ composite PiG film shows a luminance saturation threshold of 23.08 W mm−2, which is 26.3% higher than that of the Al2O3-free LSN:Ce3+ PiG film (18.27 W mm−2). The luminous flux of the composite PiG film under blue laser excitation is improved by 51.4% and reaches 3120 lm, and the luminous flux of the laser-driven white light can reach up to 2886 lm. It indicates that the Al2O3–LSN:Ce3+ composite PiG film would be an interesting color converter for producing high-brightness laser-driven white light. [ABSTRACT FROM AUTHOR]

Aim: Guided by the social embeddedness model of thriving at work, this paper explores how nursing organizational culture, work engagement and affective commitment affect nurses' thriving at work. Background: Thriving at work has implications for better employee and organization outcomes. The antecedents of thriving at work among the nursing population needs to be expanded by analysing the cross‐level impact of organizational and individual characteristics. Methods: A cross‐sectional design was used to collect data from 1437 frontline nurses in a tertiary teaching hospital in China between April and May 2020 through an online survey about perceived nursing culture, work engagement, affective commitment and thriving at work. Data were analysed using SPSS, and a structural equation model was established using the PROCESS macro. Results: Our results showed that work engagement and affective commitment mediated the relationship between nurses' perceived nursing culture and their thriving at work. Among nurses, work engagement was positively correlated to affective commitment. Conclusion: Our study confirmed the social embeddedness model of thriving at work by showing that both contextual and dispositional factors can influence nurses' thriving at work. Nurse leaders can foster nursing staff's thriving at work by building an inclusive work environment and by providing adequate resources to staff. Future research is needed to elaborate on employee and organizational outcomes associated with thriving at work. Impact: Nurse leaders should be the advocate for nurses to improve their organizational identification, fostering their thriving at work. Individual nurses can also take an active role in developing work‐related resources to sustain their thriving through self‐adaption processes. Collective thriving in the nursing workforce is needed to overcome adversity and hardship in the ever‐changing and increasingly demanding health care industry and to further contribute to the vitality of the broader social and public environments. Patient or public contribution: No patient or public contribution. This study did not involve patients, service users, caregivers or members of the public. [ABSTRACT FROM AUTHOR]