The features and survival of stage IV breast cancer patients with different metastatic sites are poorly understood. This study aims to examine the clinicopathological features and survival of stage ...IV breast cancer patients according to different metastatic sites.
Using the Surveillance, Epidemiology, and End Results database, we restricted our study population to stage IV breast cancer patients diagnosed between 2010 to 2015. The clinicopathological features were examined by chi-square tests. Breast cancer-specific survival (BCSS) and overall survival (OS) were compared among patients with different metastatic sites by the Kaplan-Meier method with log-rank test. Univariable and multivariable analyses were also performed using the Cox proportional hazard model to identify statistically significant prognostic factors.
A total of 18,322 patients were identified for survival analysis. Bone-only metastasis accounted for 39.80% of patients, followed by multiple metastasis (33.07%), lung metastasis (10.94%), liver metastasis (7.34%), other metastasis (7.34%), and brain metastasis (1.51%). The Kaplan-Meier plots showed that patients with bone metastasis had the best survival, while patients with brain metastasis had the worst survival in both BCSS and OS (p < 0.001, for both). Multivariable analyses showed that age, race, marital status, grade, tumor subtype, tumor size, surgery of primary cancer, and a history of radiotherapy or chemotherapy were independent prognostic factors.
Stage IV breast cancer patients have different clinicopathological characteristics and survival outcomes according to different metastatic sites. Patients with bone metastasis have the best prognosis, and brain metastasis is the most aggressive subgroup.
In response to the high demand of the operation reliability by implementing real-time monitoring and system health management, a robust fault estimation and fault-tolerant control approach is ...proposed for Takagi-Sugeno fuzzy systems in this study, by integrating the augmented system method, unknown input fuzzy observer design, linear matrix inequality optimization, and signal compensation techniques. Specifically, a fuzzy augmented system method is used to construct an augmented plant with the concerned faults and system states being the augmented states. An unknown input fuzzy observer technique is thus utilized to estimate the augmented states and decouple unknown inputs that can be decoupled. A linear matrix inequality approach is further addressed to ensure the global stability of the estimation error dynamics and attenuate the influences from the unknown inputs that cannot be decoupled. As a result, the robust estimates of the concerned faults and system states can be obtained simultaneously. Based on the fault estimates, a signal compensation scheme is developed to remove the effects of the faults on the system dynamics and outputs, leading to a stable dynamic satisfying the expected performance. Finally, the effectiveness of the proposed Takagi-Sugeno model based fault estimation and signal compensation algorithms is demonstrated by a case study on a 4.8-MW wind turbine benchmark system.
Robust fault estimation plays an important role in real-time monitoring, diagnosis, and fault-tolerance control. Accordingly, this paper aims to develop an effective fault estimation technique to ...simultaneously estimate the system states and the concerned faults, while minimizing the influences from process/sensor disturbances. Specifically, an augmented system is constructed by forming an augmented state vector composed of the system states and the concerned faults. Next, an unknown input observer (UIO) is designed for the augmented system by decoupling the partial disturbances and attenuating the disturbances that cannot be decoupled, leading to a simultaneous estimate of the system states and the concerned faults. In order to be close to the practical engineering situations, the process disturbances in this study are assumed not to be completely decoupled. In the first part of this paper, the existence condition of such an UIO is proposed to facilitate the fault estimation for linear systems subjected to process disturbances. In the second part, robust fault estimation techniques are addressed for Lipschitz nonlinear systems subjected to both process and sensor disturbances. The proposed technique is finally illustrated by the simulation studies of a three-shaft gas turbine engine and a single-link flexible joint robot.
The abundant reserve and low cost of sodium have provoked tremendous evolution of Na-ion batteries (SIBs) in the past few years, but their performances are still limited by either the specific ...capacity or rate capability. Attempts to pursue high rate ability with maintained high capacity in a single electrode remains even more challenging. Here, an elaborate self-branched 2D SnS2 (B-SnS2) nanoarray electrode is designed by a facile hot bath method for Na storage. This interesting electrode exhibits areal reversible capacity of ca. 3.7 mAh cm–2 (900 mAh g–1) and rate capability of 1.6 mAh cm–2 (400 mAh g–1) at 40 mA cm–2 (10 A g–1). Improved extrinsic pseudocapacitive contribution is demonstrated as the origin of fast kinetics of an alloying-based SnS2 electrode. Sodiation dynamics analysis based on first-principles calculations, ex-situ HRTEM, in situ impedance, and in situ Raman technologies verify the S-edge effect on the fast Na+ migration and reversible and sensitive structure evolution during high-rate charge/discharge. The excellent alloying-based pseudocapacitance and unsaturated edge effect enabled by self-branched surface nanoengineering could be a promising strategy for promoting development of SIBs with both high capacity and high rate response.
In this paper, we aim to explore the possibility of the Transformer model in detecting the spam Short Message Service (SMS) messages by proposing a modified Transformer model that is designed for ...detecting SMS spam messages. The evaluation of our proposed spam Transformer is performed on SMS Spam Collection v.1 dataset and UtkMl's Twitter Spam Detection Competition dataset, with the benchmark of multiple established machine learning classifiers and state-of-the-art SMS spam detection approaches. In comparison to all other candidates, our experiments on SMS spam detection show that the proposed modified spam Transformer has the optimal results on the accuracy, recall, and F1-Score with the values of 98.92%, 0.9451, and 0.9613, respectively. Besides, the proposed model also achieves good performance on the UtkMl's Twitter dataset, which indicates a promising possibility of adapting the model to other similar problems.
Tribo-behavior of tetrahedral amorphous carbon nitride (ta-CNx) coating in unlubricated condition was investigated in this study. Sliding against steel, low nitrogen content ta-CNx exhibits much ...lower friction and wear as temperature increases, with less adhesion wear than ta-C and remained relatively higher hardness (45.01 GPa). Nevertheless, against sapphire ta-C outperforms ta-CNx greatly, and graphitization could be found at 120 °C. With atmosphere humidity increasing, ta-CNx shows significantly decreased friction, implying the tribo-character of high sp3 bonding structure. Meanwhile, dry air seems to be the harshest condition for ta-CNx, since O2 in the atmosphere might lead to oxidized wear of ta-CNx even under room temperature. Furthermore, in humid N2, as an inert gas with high humidity, ta-CNx shows the lowest friction and wear.
•Tribological properties of ta-CNx coating under unlubricated condition were studied.•As temperature rising ta-CNx shows distinct tribo-behavior against steel or sapphire.•Against steel low nitrogen ta-CNx shows lower friction and wear than ta-C over 50 °C.•Friction of ta-CNx was greatly affected by the humidity and oxygen in the atmosphere.
Enzymatic self-powered biosensors have been widely studied due to their advantages of high selectivity, simple assembly, small size, low cost and no external power supply. However, the low activity ...and stability of the enzyme lead to lower power density and short service life of the sensor, which seriously limits its practical application. Herein, a self-powered electrochemical biosensor (SPEB) based on in situ growth of enzyme/copper phosphate on carbon cloth surface was developed through chemical liquid coprecipitation technology. The biosensor has a higher power density of 547.97 μW·cm−3, the linear detection range of 0.1–0.5 mM, and the lowest detection limit of 2.05 μM. The unique electrochemical performance of the as-prepared biosensor is mainly due to the special three-dimensional (3D) flower structure of the enzyme/copper phosphate organic/inorganic hybrids, which has a unique flower-like structure and high specific surface area, allowing more exposure to the active site of the enzyme. Moreover, the enzyme has a synergistic effect with Cu3(PO4)2, which not only ensures the specificity of the enzyme, but also improves the catalytic activity and stability of the enzyme, improving the performance of SPEB. The SPEB is expected to be applied to glucose detection.
•A self-powered electrochemical biosensor for glucose detection was developed.•Flexible carbon cloth is combined with enzyme/copper phosphate for glucose detection.•Synergistic effect of enzyme and copper phosphate improves the biosensor’s stability.•Self-powered electrochemical biosensors have high power density.
•The effects of flash drought on productivity and the relationship among influencing factors are revealed.•The sensitivity and anomaly of grassland productivity response to flash drought are ...discussed.•The time stage and type of flash drought had the greatest impact on grassland productivity.•The drought tolerance of grassland and the grassland type with the greatest risk of flash drought are determined.
Flash droughts have attracted worldwide attention because of their rapid outbreak and extensive influence. However, studies regarding the characteristics and effects of flash droughts in grassland ecosystems are insufficient. In this study, the frequency and intensity characteristics of flash droughts in the Xilinguole Grassland in China were studied. The response characteristics of the productivity of different types of grassland to flash droughts and the relationship between these characteristics and the drought tolerance of grassland were revealed. The results show that (1) flash droughts had the greatest impact on grassland net primary productivity (NPP) and rain use efficiency (RUE) in summer and spring, respectively, with a level of intensity above that of moderate drought. Strong evapotranspiration flash droughts (SEFD) require more attention from decision-makers than heat wave flash droughts (HWFD). A higher frequency and intensity of flash droughts had a greater impact on vegetation. (2) Flash droughts caused moderate negative anomalies in the NPP and RUE indices in more than 90 % of the grasslands. The longest lag time of the NPP response to flash droughts was 2 months, and NPP anomalies were affected by flash droughts for nearly 2 months. RUE was more sensitive to flash droughts than NPP. RUE responded to flash droughts within 10 days, with a decrease of more than 80 % in magnitude, which was 30 % higher than that of the NPP, and the duration of the anomaly was half that of the NPP. (3) Grasslands with a high sensitivity to flash droughts had shorter response durations, fewer abnormalities, better recovery abilities and better drought tolerance. The drought tolerance of grasslands did not increase in association with large NPP and RUE values. Desert grasslands were the most drought tolerant, while meadow grasslands were the least drought tolerant, with the highest risk of flash droughts. This study provides theoretical support for improving the ability of an ecosystem to cope with flash drought risk and scientific grassland management.
Tetrahedral amorphous carbon nitride (ta-CNx), as an emerging and promising diamond-like carbon (DLC), has better mechanical properties than amorphous carbon nitride (a-CNx) to ensure the sufficient ...durability, and overcomes the limit of high internal stress of tetrahedral amorphous carbon (ta-C), which makes ta-CNx coatings of great worth of research for the tribological and mechanical applications. In this study, we present the effects of oil temperature and counterpart material on the wear behavior of ta-CNx coatings under base-oil lubrication, and further clarify the wear mechanism. ta-C and ta-CNx coatings with N/C atomic ratio of 2.2% and 11.0% were deposited by an ion beam assisted filtered arc deposition (IBA-FAD) system, and the tribological tests were performed using a ball-on-disk tribo-tester with ta-C and ta-CNx coated steel ball sliding against uncoated disk under base-oil lubrication. The results show that nitrogen doping tends to decrease the hardness and Young's modulus by reducing the sp3 structure. Sliding against steel disk, with increase of sliding distance ta-CNx shows obviously distinct wear behavior compared to ta-C, much more slowly increasing wear volume, exhibiting excellent wear resistance. Increasing oil temperature from room temperature to 120°C results in rising wear rates of all the three coatings, with totally worn out ta-C and much lower wear rate of ta-CNx, which decreases by more than half than ta-C for high nitrogen content ta-CNx. However, as the counterpart material changed from steel to alumina, the wear rate presents oppositely increasing tendency with N/C ratio, probably caused by the change of deciding factor to hardness in this mechanical wear. It is found that the wear performance of ta-CNx coating has a clear dependence on the oil temperature and counterpart material. Based on the results, the better wear resistance of softer ta-CNx against steel could be attributed to the less tribo-chemical wear between carbon and iron, due to the nitrogen doping partial passivation effect.
•Against steel ta-CNx shows much lower wear with distance and longer life than ta-C.•N doping into ta-CNx could effectively decrease the high wear caused by temperature.•Against alumina ta-CNx shows oppositely increasing wear rate with N content.•N doping could increase fracture toughness of ta-CNx, bearing higher load.
Nowadays, dielectric materials with excellent mechanical and hydrophobic properties are desired for use in the integrated circuits (ICs). For this reason, low dielectric constant ...fluorographene/polyimide (FG/PI) composite films were prepared by a facile solution blending method, suggesting that the mechanical, electrical, hydrophobic and thermal properties were significantly enhanced in the presence of FG. With addition of 1wt% FG, the tensile strength, Young’s modulus and elongation at break were dramatically increased by 139%, 33% and 18% respectively when compared with pure PI film. Furthermore, composite films exhibit superior hydrophobic and thermal stability performance. Especially, the FG/PI film with 0.5wt% of FG possessing a low dielectric constant of 2.48 and a good electrical insulativity that is lower than 10−14Sm−1. Therefore, by their excellent performance, FG/PI hybrid films represent suitable candidate solutions with applications in the microelectronics and aerospace industries.
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