Search

Low triiodothyronine syndrome （LT3S） refers to the abnormal metabolism of thyroid hormones associated with critical illness， but without obvious symptoms of hypothyroidism. LT3S is closely associated with many critical diseases， such as severe burns， etc. During the occurrence and development of critical illness， many factors can induce LT3S by affecting the secretion， transfer and metabolism of thyroid hormones. LT3S is a risk factor for the development of critical illness and the occurrence of complications. It is a good indicator for evaluating the severity and prognosis of critical diseases. In this article， the pathogenesis， relationship with critical illness and treatment progress of LT3S were reviewed.

Intelligent assembly is a bottleneck to be broken with urgency in the on-going revolution of manufacturing industry. However, computer-aided assembly modeling as an important supporting technology is still suffering from the problems of too many manual interventions and low-level intelligence. An intelligent assembly modeling technology was previously developed based on design intent (DI), however there lacks systematical and supportive product information model. Consequently, a novel product information model that can capture DI for computer-aided intelligent assembly modeling is established, based on the previously developed concept of interaction feature pair (IFP). The corresponding meta class model is also constructed utilizing the object-oriented technology. On this basis, the implementation process of the product information model, as well as algorithms supporting the process of computer-aided intelligent assembly modeling, is clarified, and the algorithms include IFP identification and intelligent part matching. Computer-aided intelligent assembly modeling prototype system based on the product information model, together with a case study, validated the feasibility of the proposed technology.

For high-power piezoelectric ceramics to operate stably under high alternating electric fields, they require co-high values of the piezoelectric coefficient (d33), mechanical quality factor (Qm), and Curie temperature (Tc). Here, 0.04Pb(Mn1/3Nb2/3)O3-0.96Pb(Zr0.505Ti0.495)O3-0.005Fe2O3-0.002Sc2O3 (ceramic 1)has a tetragonal phase near the piezoelectric morphotropic phase boundary, which significantly improved the Qm value of the ceramic while maintaining high d33 and Tc. It exhibits advantages in multi-parameter co-high values, with d33 = 340 pC/N, dielectric loss tanδ = 0.24%, Qm = 2200, electromechanical coupling coefficient (kp) = 0.59, permittivity (εr) = 1450 and Tc = 377 °C. The figure of merit (FOM = Qm × d33) value of ceramic 1 is as high as 748 nC/N at room temperature, surpassing most high-power piezoelectric ceramics. Under an alternating electric field of 40 V/mm at 92 kHz, the ceramic achieves a vibration velocity of 0.4 m/s, which is 3.6 times higher than that of commercial piezoelectric ceramic under the same electric field. These results indicate that the ceramic 1 is highly suitable for advanced high-power piezoelectric applications. [ABSTRACT FROM AUTHOR]

Objective To explore the effect of E3 ligase neuregulin receptor degradation protein 1 (Nrdp1) regulating macrophage polarization on the function of fibroblasts. Methods Lipopolysaccharide (LPS) and interferon-γ (IFN-γ) were combined to induce mouse primary peritoneal macrophages to M1 macrophages (M1), and IL-13 was used to induce macrophages to M2 macrophages (M2). Then flow cytometry and Western blotting were used to detect M1 surface marker protein CD11c and its specific secretion inducible nitric oxide synthase (iNOS), and M2 surface marker protein CD206 and the secretion arginase 1 (Arg1). After the mouse macrophages was transfected with siRNA-Nrdp1 transiently for 24 h, the expression of Nrdp1 was detected by Western blotting. A Transwell co-culture system was established for macrophages and fibroblasts, and was induced under different conditions. The co-cultured cells were divided into LPS group (co-induction of LPS and IFN-γ), LPS-NC group (co-induction and siRNA of irrelevant sequence), LPS-siRNA-Nrdp1 group (co-induction of LPS and siRNA-Nrdp1), IL-13 group, IL-13-NC group and IL-13-siRNA-Nrdp1 group. After co-culture for 8, 12 and 24 h, CCK-8 assay was employed to detect the proliferation of fibroblasts, and ELISA to measure the contents of transforming growth factor β1 (TGF-β1) and type Ⅰ procollagen. Analysis of variance of factorial designs and Bonferroni test were used for statistical analysis for the data. Results The proportion of CD11c positive cells was significantly higher in the LPS-induced macrophages than the non-induced cells (P < 0.05), and similar result was seen in the IL-13-induced macrophages for CD206 expression (P < 0.05). Western blot analysis indicated the levels of iNOS and Arg1 were obviously higher in the LPS- and IL-13-induced macrophages than the non-induced control cells, respectively (P < 0.01). Transient transfection of siRNA-Nrdp1 resulted in notably lower expression of Nrdp1 when compared with the blank control and negative control transfection (both P < 0.01). In the co-culture system for 24 h, CCK8 assay showed the count of fibroblasts was significantly lower in the IL-13-siRNA-Nrdp1 group than the IL-13 and IL-13-NC groups (P < 0.01), and ELISA indicated that the content of TGF-β1 was lower in the IL-13-siRNA-Nrdp1 group than the IL-13 and IL-13-NC groups (P < 0.01), and that of type Ⅰ procollagen was lower in the IL-13-siRNA-Nrdp1 group than the IL-13 groups (P < 0.01). Conclusion Interference of Nrdp1 synthesis by siRNA can affect the polarization of macrophages to M2 type, inhibit the proliferation of fibroblasts in the co-culture system of M2 type macrophages and fibroblasts, and reduce the TGF-β1 and type Ⅰ procollagen in the co-culture system.

The need for cross-comparison and validation of all-weather Land Surface Temperature (LST) products has arisen due to the release of multiple such products aimed at providing comprehensive all-weather monitoring capabilities. In this study, we focus on validating two well-established all-weather LST products (i.e. MLST-AS and TRIMS LST) against in-situ measurements obtained from four high-quality LST validation sites: Evora, Gobabeb, KIT-Forest, and Lake Constance. For the land sites, MLST-AS exhibits better accuracy, with RMSEs ranging from 1.6 K to 2.1 K, than TRIMS LST, the RMSEs of which range from 1.9 K to 3.1 K. Because MLST-AS pixels classified as "inland water" are masked out, the validation over Lake Constance is limited to TRIMS LST: it yields a RMSE of 1.6 K. Furthermore, the validation results show that MLST-AS and TRIMS LST exhibit better accuracy under clear-sky conditions than unclear-sky conditions across all sites. Since the accuracy of the all-weather LST products is considerably affected by the input clear-sky LST products, we further compare the all-weather LST with the corresponding input clear-sky LST to conduct an error source analysis. Considering the clear-sky pixels on MLST-AS directly using the estimates from MLST, the error source analysis is limited to examining TRIMS LST and its input (i.e. MODIS LST). The findings indicate that TRIMS LST is highly correlated with MODIS LST. The investigation and validation of the two selected all-weather LST products objectively evaluate their accuracy and stability, which provides important information for applications of these all-weather LST products. [ABSTRACT FROM AUTHOR]

Integrated nanoelectromechanical systems (NEMS) with nm-scale piezoelectric films exhibit enormous advantages compared with traditional microelectromechanical systems. Herein, the flexible PZT ferroelectric films with 50–200 nm thickness were achieved, and their piezoelectric d33 rapidly enhanced with the thickness of film increasing and the thickness of mica substrate decreasing. The d33 value of the 80 nm-thick PZT film increases from 180 to 220 pC/N with the thickness of mica substrate reducing from 0.2 mm to 10 μm to largely decrease clamping strain between substrate and PZT film. Furthermore, the flexible mica substrate largely increases both the piezoelectric effect and the inverse piezoelectric effect of PZT films. These nm-scale PZT films with robust piezoelectricity will encourage the creation of new NEMS and piezoelectric devices that are flexible. [ABSTRACT FROM AUTHOR]

High‐power piezoelectric ceramics are typically driven to output vibration velocity (v0) under high AC electric fields. Herein, the Fe2O3 doped 0.125 Pb(Zn1/3Nb2/3) O3–0.075 Pb(Mn1/3Nb2/3)O3–0.8 Pb(Zr0.48Ti0.52)O3(PZMNZT–xFe; x = 0.05–0.35) piezoelectric ceramics were prepared to enhance v0, and the favorable comprehensive electrical properties, such as d33 = 315 pC/N, Qm = 1738, kp = 0.58, kt = 0.48, εr = 1156, tan δ = 0.4%, and Tc = 320°C, were achieved in the PZMNZT–0.15Fe ceramic. Most importantly, the PZMNZT–0.15Fe ceramic presented a reliable v0 of 0.90 m/s, which was 2.25 times of the commercial PZT4 ceramic (∼0.40 m/s). The excellent high‐power performance should be attributed to ordering functional elements such as crystal grains and ferroelectric domains. Overall, this work reveals that the PZMNZT–0.15Fe ceramic is competitive for high‐power applications. [ABSTRACT FROM AUTHOR]

To enhance the anti-submarine and search capabilities of multiple Unmanned Aerial Vehicle (UAV) groups in complex marine environments, this paper proposes a flexible action-evaluation algorithm known as Knowledge-Driven Soft Actor-Critic (KD-SAC), which can effectively interact with real-time environmental information. KD-SAC is a reinforcement learning algorithm that consists of two main components: UAV Group Search Knowledge Base (UGSKB) and path planning strategy. Firstly, based on the UGSKB, we establish a cooperation search framework that comprises three layers of information models: the data layer provides prior information and fundamental search rules to the system, the knowledge layer enriches search rules and database in continuous searching processes, and the decision layer utilizes above two layers of information models to enable autonomous decision-making by UAVs. Secondly, we propose a rule-based deductive inference return visit (RDIRV) strategy to enhance the knowledge base of search. The core concept of this strategy is to enable UAVs to learn from both successful and unsuccessful experiences, thereby enriching the search rules based on optimal decisions as exemplary cases. This approach can significantly enhance the learning performance of KD-SAC. The subsequent step involves designing an event-based UGSKB calling mechanism at the decision-making level, which calls a template based on the target and current motion. Finally, it uses a punishment function, and is then employed to achieve optimal decision-making for UAV actions and states. The feasibility and superiority of our proposed algorithm are demonstrated through experimental comparisons with alternative methods. The final results demonstrate that the proposed method achieves a success rate of 73.63% in multi-UAV flight path planning within complex environments, surpassing the other three algorithms by 17.27%, 29.88%, and 33.51%, respectively. In addition, the KD-SAC algorithm outperforms the other three algorithms in terms of synergy and average search reward. [ABSTRACT FROM AUTHOR]

In seasonally frozen regions, highway tunnels are prone to shallow buried bias pressures near the inlet/outlet, which leads to highway tunnels not only bearing asymmetric loads, but also facing the threat of extreme weather. However, there is still no clear understanding of the temperature field for topographically biased tunnel in seasonally frozen regions at present. Taking the Huitougou tunnel of Hegang-Dalian expressway as the object, this paper uses on-site monitoring, theoretical analysis, and numerical simulation to study the distribution law and influence factors of temperature field for topographically biased tunnel in seasonally frozen regions. The numerical results of the temperature field are in good agreement with the on-site monitoring data, which verified the accuracy of this numerical model based on the aerodynamic principle, turbulence model, and wall function method. Meanwhile, the effect of different slope angle and overburden thickness on the temperature field of the tunnel is further analyzed. It is found that when the slope angle increases, the temperature field in the tunnel surrounding rock changes accordingly. The connecting area between the surface and the tunnel temperature field is deflected from arch crown to the arch shoulder of the tunnel, resulting in a large change in the temperature of the shallow buried side, while minor change in the temperature of the deep buried side. The freezing depth of surrounding rock decreases with the rising slope angle. As the overburden thickness gradually increases, the temperature field of the surface surrounding rock and the tunnel surrounding rock gradually change from mutual influence to non-influence. When the overburden thickness exceeds 15 m, a "isolated temperature zone" appears in the middle with a temperature of 6~7 °C, the temperature field of the tunnel surrounding rock is basically not affected by the surface air temperature. These results can provide important theoretical and engineering guidance for the evaluation, construction, and maintenance of tunnel engineering in seasonally frozen regions. [ABSTRACT FROM AUTHOR]

High-power ultrasonic transducers need piezoelectric ceramics with a high piezoelectric coefficient, d33, high quality factor, Qm, large coercivity field, EC, high Curie temperature TC , etc, so that they can work in a high electric field for a long time. Here, 0.04Pb (Mn1/3Nb2/3) O3–0.96Pb (Zr0.515Ti0.485) O3-xmol%Nb2O5 (PMN–PZT-x%Nb2O5, x = 0.0–1.0) ceramics with high piezoelectric performance and cost-effective merits were prepared using low-cost industry-grade raw materials. The PMN–PZT-0.6%Nb2O5 ceramic shows the optimal comprehensive electrical properties, such as a high d33 of 411 pC/N, a Qm of 653, a dielectric loss tanδ of 0.30%, a relative permittivity εr of 1457, an electromechanical coupling factor kp of 0.58, a high TC of 355°C, and a large EC of 1.3 kV/mm. Under the electric field of 100 V/mm, the PMN–PZT-0.4%Nb2O5 ceramic shows a large vibration velocity of 0.9 m/s. Since PMN–PZT-x%Nb2O5 ceramics have the merits of high quality, high-cost performance ratio, and easy mass production, they are promising for applications of high-power devices. [ABSTRACT FROM AUTHOR]