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Fine-sized oxide particles are often used to improve the mechanical properties and service life of materials. Particularly, rare earth-silicate particles have high deformability and promising applications in metallic materials and ceramic coatings. To study the formation of rare earth-silicate particles and control their physical characteristics, we apply first-principles calculations and investigate the nucleation mechanism of Ce2Si2O7 particles at the atomic scale. The estimated thermodynamic properties of (Ce2Si2O7)n (n = 1 – 4) agree reasonably well with the experimental data, indicating that the first-principles calculation is reliable. Furthermore, the potential of a preformed nuclear phase for Ce2Si2O7 particles is thermodynamically demonstrated. Four formation pathways of Ce2Si2O7 particles are proposed and discussed. Based on thermodynamic principles, the most probable formation pathway is [Ce]+[Si]+[O]→(Ce2Si2O7)n→Ce2Si2O7(s), and another formation pathway is considered the least likely, (SiO2)n+(Ce2O3)n→(Ce2Si2O7)n→Ce2Si2O7(s). [ABSTRACT FROM AUTHOR]

This guideline prescribes the technical requirements for the design and operation of long-term exposure sites in marine environments. The technical content includes the design of exposure site, the monitoring of environmental conditions, the monitoring of exposed specimens, the data management and the maintenance of exposure facilities. The design of exposure site covers the choice of exposure sites, the exposure infrastructure and facilities, exposure specimens and their placing and protection. Then, the guideline defines the environmental factors to be monitored and the corresponding monitoring methods. For the exposed specimens, the guideline specifies the target performance to monitor, the sampling, the testing and the reporting of exposure results. The data management deals with such aspects as the data storage, data transmission and the data sharing. At the end, the guideline gives the principles for the maintenance of the exposure facilities. This guideline summarizes the best practice of long-term exposure in marine environments, and it is expected to support the normalization of exposure practice and to generate more added values from this practice. [ABSTRACT FROM AUTHOR]

Real-time and accurate estimation of surgical hemoglobin (Hb) loss is essential for fluid resuscitation management and evaluation of surgical techniques. In this study, we aimed to explore a novel surgical Hb loss estimation method using deep learning-based medical sponges image analysis. Whole blood samples of pre-measured Hb concentration were collected, and normal saline was added to simulate varying levels of Hb concentration. These blood samples were distributed across blank medical sponges to generate blood-soaked sponges. Eight hundred fifty-one blood-soaked sponges representing a wide range of blood dilutions were randomly divided 7:3 into a training group (n = 595) and a testing group (n = 256). A deep learning model based on the YOLOv5 network was used as the target region extraction and detection, and the three models (Feature extraction technology, ResNet-50, and SE-ResNet50) were trained to predict surgical Hb loss. Mean absolute error (MAE), mean absolute percentage error (MAPE), coefficient (R2) value, and the Bland–Altman analysis were calculated to evaluate the predictive performance in the testing group. The deep learning model based on SE-ResNet50 could predict surgical Hb loss with the best performance (R2 = 0.99, MAE = 11.09 mg, MAPE = 8.6%) compared with other predictive models, and Bland–Altman analysis also showed a bias of 1.343 mg with narrow limits of agreement (− 29.81 to 32.5 mg) between predictive and actual Hb loss. The interactive interface was also designed to display the real-time prediction of surgical Hb loss more intuitively. Thus, it is feasible for real-time estimation of surgical Hb loss using deep learning-based medical sponges image analysis, which was helpful for clinical decisions and technical evaluation. [ABSTRACT FROM AUTHOR]

This article investigates the design of hybrid digital and analog transmit/receive beamformers for orthogonal frequency division multiplexing dual-function radar-communication system. Specifically, we model the hybrid beamforming design by simultaneously optimizing the spectrum efficiency of communication and approximate output signal-to-interference noise ratio of radar sensing, through a flexible performance tradeoff. Due to the coupling relationship among the beamformers in the hybrid structure and the independence of signals in different frequency bands, the resultant optimization problem is NP-hard. Hence, a consensus alternating direction method of multipliers approach is designed to tackle the difficulty. The transmit hybrid beamformer is obtained by introducing auxiliary variables and exploiting the block continuous upper bound minimization method. Then, the receive beamformer can be optimized via generalized eigenvalue decomposition. Numerical simulations are provided to demonstrate the effectiveness of the proposed scheme. [ABSTRACT FROM AUTHOR]

We numerically investigate the mesoscopic electronic transport properties of Bernal-stacked bilayer/trilayer graphene connected with four monolayer graphene terminals. In armchair-terminated metallic bilayer graphene, we show that the current from one incoming terminal can be equally partitioned into other three outgoing terminals near the charge-neutrality point, and the conductance periodically fluctuates, which is independent of the ribbon width but influenced by the interlayer hopping energy. This finding can be clearly understood by using the wave function matching method, in which a quantitative relationship between the periodicity, Fermi energy, and interlayer hopping energy can be reached. Interestingly, for the trilayer case, when the Fermi energy is located around the charge-neutrality point, the fractional quantized conductance 1/(4e2h) can be achieved when system exceeds a critical length. [ABSTRACT FROM AUTHOR]

We study theoretically the construction of topological conducting domain walls with a finite width between AB/BA stacking regions via finite element method in bilayer graphene systems with tunable commensurate twisting angles. We find that the smaller is the twisting angle, the more significant the lattice reconstruction would be, so that sharper domain boundaries declare their existence. We subsequently study the quantum transport properties of topological zero-line modes which can exist because of the said domain boundaries via Green's function method and Landauer—Büttiker formalism, and find that in scattering regions with tri-intersectional conducting channels, topological zero-line modes both exhibit robust behavior exemplified as the saturated total transmission Gtot ≈ 2e2/h and obey a specific pseudospin-conserving current partition law among the branch transport channels. The former property is unaffected by Aharonov—Bohm effect due to a weak perpendicular magnetic field, but the latter is not. Results from our genuine bilayer hexagonal system suggest a twisting angle around θ ≈ 0.1° for those properties to be expected, consistent with the existing experimental reports. [ABSTRACT FROM AUTHOR]

This paper reviews the technical aspects related to the long-term field exposure practice in marine environments, based on the return of experiences of major marine exposure sites in world-wide scope. The long-term exposure practice helps both the research on durability mechanisms of structural concretes under real environments and the calibration of durability models to support the life-cycle management of concrete structures. The presentation of the field exposure data can be categorized into the information relevant to exposure sites, the data related to the exposed materials and specimens, the information of environmental actions, and the data related to the performance of materials. A standardized presentation of these data can help the efficiency of data sharing and exploitation. The exploitation of exposure data employs various models to represent the chloride ingress and the induced corrosion risk of the embedded steel bars. There are needs for models addressing the strong environment-material interactions, and simple yet reliable durability indicators for engineering use. The design and operation of exposure stations need the careful choice of exposure sites and specimens, the appropriate scheme for monitoring and inspection of exposed specimens, the systematic recording and management of exposure data, and the regular maintenance of exposure facilities. The support of exposure data for life-cycle management is demonstrated through the durability planning of a real project case. The good practice of long-term field exposure is summarized in the end. [ABSTRACT FROM AUTHOR]

Objective: To analyze and compare the imaging workflow, radiation dose, and image quality for COVID-19 patients examined using either the conventional manual positioning (MP) method or an AI-based automatic positioning (AP) method. Materials and methods: One hundred twenty-seven adult COVID-19 patients underwent chest CT scans on a CT scanner using the same scan protocol except with the manual positioning (MP group) for the initial scan and an AI-based automatic positioning method (AP group) for the follow-up scan. Radiation dose, patient positioning time, and off-center distance of the two groups were recorded and compared. Image noise and signal-to-noise ratio (SNR) were assessed by three experienced radiologists and were compared between the two groups. Results: The AP operation was successful for all patients in the AP group and reduced the total positioning time by 28% compared with the MP group. Compared with the MP group, the AP group had significantly less patient off-center distance (AP 1.56 cm ± 0.83 vs. MP 4.05 cm ± 2.40, p < 0.001) and higher proportion of positioning accuracy (AP 99% vs. MP 92%), resulting in 16% radiation dose reduction (AP 6.1 mSv ± 1.3 vs. MP 7.3 mSv ± 1.2, p < 0.001) and 9% image noise reduction in erector spinae and lower noise and higher SNR for lesions in the pulmonary peripheral areas. Conclusion: The AI-based automatic positioning and centering in CT imaging is a promising new technique for reducing radiation dose and optimizing imaging workflow and image quality in imaging the chest. Key Points: • The AI-based automatic positioning (AP) operation was successful for all patients in our study. • AP method reduced the total positioning time by 28% compared with the manual positioning (MP). • AP method had less patient off-center distance and higher proportion of positioning accuracy than MP method, resulting in 16% radiation dose reduction and 9% image noise reduction in erector spinae. [ABSTRACT FROM AUTHOR]

The article [Title], written by [AuthorNames], was originally published electronically on the publisher's internet portal (currently SpringerLink) on 3 December 2018 without open access. [ABSTRACT FROM AUTHOR]

GSTM1 gene encodes a key enzyme involved in the metabolism of xenobiotics, and its polymorphisms have been related to individual susceptibility to several malignancies. Many molecular epidemiological studies were performed to investigate the association between the GSTM1 null polymorphism and lung cancer susceptibility in East Asia. However, the results were inconsistent. In order to derive a more precise estimation, we conducted this meta-analysis involving 5,909 lung cancer cases and 7,067 controls from 35 studies. We used crude odds ratios (ORs) with 95 % confidence intervals (CIs) to assess the association between GSTM1 null genotype and the risk of lung cancer. Our study found that the GSTM1 null genotype appeared to be a significant risk factor for lung cancer in East Asia population (OR = 1.30, 95 % CI = 1.17-1.45, P < 0.0001, and I = 54.0 %). [ABSTRACT FROM AUTHOR]

To study the relationship between material composition, curing conditions and strength development, the study simulated high-strength precast concrete pile production, and a high-strength mortar up to 90 MPa was designed and a hot-water pool was built for concrete curing. The major point of the study was to achieve a high early strength by using cement/metakaolin systems without autoclave curing with high-pressure steam. By means of XRD and thermal analysis, the progress of the hydration of the cement pastes blended with metakaolin was characterized. The main results indicate that high strength can be obtained at early age by the use of metakaolin and thermal treatment (hot-water curing). The improvement in strength of mortars with metakaolin can be explained by an increase in the amount of C-S-H and C-S-A-H hydrated phases and a decrease in the amount of calcium hydration(CH). Further more, a decrease in Ca/Si ratio of the matrix was observed from the results of EDX analysis, which also leaded to an improvement of the compressive strength. These results are of great importance for the high-strength precast concrete manufacturing industry. [ABSTRACT FROM AUTHOR]