Drying Shrinkage of Hardened Cement Paste and Its Relationship to the Microstructure

The aim of the present study is to relate microstructure to the drying shrinkage of hardened cement paste. Three microstructural features, calcium silicate hydrate(C-S-H), calcium hydroxide(CH) and pore structure were studied. A new method to determine the C-S-H content of hardened cement paste is presented. Drying shrinkage behavior of cement pastes were investigated by drying specimens through successive steps of RH 100% to 7% RH and re-saturating the specimens. The total shrinkage of cement paste after drying to 7% RH and irreversible shrinkage were decreased with the increasing amount of C-S-H and CH. Prolonged curing resulted in a paste with finer pore structure and more weight loss when dried in lower humidity. For a certain paste, the same amount of weight loss induced less liner shrinkage in the 54-23% RH range than in the 100-54% RH range. The total shrinkage of cement paste after drying to 7% RH and irreversible shrinkage decreases with increasing amount of C-S-H and CH. The formation of C-S-H increase the resistance of cement paste to shrinkage rather than enhance drying shrinkage by providing more gel pores and empty of which would bring large stress on the solid skeleton

Climate change : strategies for mitigation and adaptation

The sustainability of life on Earth is under increasing threat due to humaninduced climate change. This perilous change in the Earth's climate is caused by increases in carbon dioxide and other greenhouse gases in the atmosphere, primarily due to emissions associated with burning fossil fuels. Over the next two to three decades, the effects of climate change, such as heatwaves, wildfires, droughts, storms, and floods, are expected to worsen, posing greater risks to human health and global stability. These trends call for the implementation of mitigation and adaptation strategies. Pollution and environmental degradation exacerbate existing problems and make people and nature more susceptible to the effects of climate change. In this review, we examine the current state of global climate change from different perspectives. We summarize evidence of climate change in Earth’s spheres, discuss emission pathways and drivers of climate change, and analyze the impact of climate change on environmental and human health. We also explore strategies for climate change mitigation and adaptation and highlight key challenges for reversing and adapting to global climate change

Correlation between neutrophil count and prognosis in STEMI patients with chronic renal dysfunction: a retrospective cohort study

Neutrophil is a key element in inflammation and stress disease, which are associated with poor clinical outcomes in various cardiac diseases. However, the clinical availability of neutrophil in patients with ST-elevation myocardial infarction (STEMI) and chronic renal dysfunction has not been known. Accordingly, we designed this retrospective cohort study to evaluate the differences of major adverse cardiovascular events incidence between renal dysfunctional STEMI patients with normal and high neutrophil levels. The primary end point was all-cause mortality. We analyzed 377 consecutive STEMI patients with chronic renal dysfunction. The results showed that during 12-48 months follow-up, death from any-cause occurred in 1.4% patients (4 of 290) in normal-level neutrophil group, as compared with 3.4% in high-level neutrophil group (3 of 87) (hazard ratio, 2.174 95% confidence interval, 1.024-10.248; P = 0.025). Kaplan-Meier survival analysis showed that there were significant differences between the two groups with respect to the risk of death (P=0.018), and heart failure (P=0.037)

Attention-Based Pyramid Network for Segmentation and Classification of High-Resolution and Hyperspectral Remote Sensing Images

Unlike conventional natural (RGB) images, the inherent large scale and complex structures of remote sensing images pose major challenges such as spatial object distribution diversity and spectral information extraction when existing models are directly applied for image classification. In this study, we develop an attention-based pyramid network for segmentation and classification of remote sensing datasets. Attention mechanisms are used to develop the following modules: (i) a novel and robust attention-based multi-scale fusion method effectively fuses useful spatial or spectral information at different and same scales; (ii) a region pyramid attention mechanism using region-based attention addresses the target geometric size diversity in large-scale remote sensing images; and (iii) cross-scale attention in our adaptive atrous spatial pyramid pooling network adapts to varied contents in a feature-embedded space. Different forms of feature fusion pyramid frameworks are established by combining these attention-based modules. First, a novel segmentation framework, called the heavy-weight spatial feature fusion pyramid network (FFPNet), is proposed to address the spatial problem of high-resolution remote sensing images. Second, an end-to-end spatial-spectral FFPNet is presented for classifying hyperspectral images. Experiments conducted on ISPRS Vaihingen and ISPRS Potsdam high-resolution datasets demonstrate the competitive segmentation accuracy achieved by the proposed heavy-weight spatial FFPNet. Furthermore, experiments on the Indian Pines and the University of Pavia hyperspectral datasets indicate that the proposed spatial-spectral FFPNet outperforms the current state-of-the-art methods in hyperspectral image classification

Formation control of UAVs based on artificial potential field

The problem of UAVs’ formation control in the process of motion is investigated in this paper. A formation control method based on artificial potential field of UAVs is proposed, established on the collision avoidance, aggregation and speed matching rules of UAVs. First establish the UAVs’ kinetic model in accordance to the motion rules, then design the formation control algorithm based on artificial potential field function, which is used to control the formation during the movement of UAVs. Finally, the results of simulation experiment show that the proposed formation control method in this paper is effective and has the advantages of easy realization, good real-time performance and excellent robustness

Formation control of UAVs based on artificial potential field

The problem of UAVs’ formation control in the process of motion is investigated in this paper. A formation control method based on artificial potential field of UAVs is proposed, established on the collision avoidance, aggregation and speed matching rules of UAVs. First establish the UAVs’ kinetic model in accordance to the motion rules, then design the formation control algorithm based on artificial potential field function, which is used to control the formation during the movement of UAVs. Finally, the results of simulation experiment show that the proposed formation control method in this paper is effective and has the advantages of easy realization, good real-time performance and excellent robustness

Negative Correlation between Serum NLRP3 and the Ratio of Treg/Th17 in Patients with Obstructive Coronary Artery Disease

Background: Regulatory T (Treg) cells are a class of anti-inflammatory lymphocyte subpopulations with a potential protective effect against atherosclerosis, whereas T helper 17 (Th17) cells have been reported to possess proatherogenic activity. It was believed that disturbed circulating Treg/Th17 balance was associated with the onset and progression of atherosclerosis. This study is designed to probe the regulative action of serum Nod-like receptor protein 3 (NLRP3) on the Treg/Th17 balance in patients with atherosclerosis. Methods: Fifty-two patients with coronary atherosclerosis and stenosis degrees of more than 50% were assigned to the coronary artery disease (CAD) group, and an equal number of people without coronary atherosclerosis were assigned to the control group (assessed by coronary angiography). Peripheral blood mononuclear cells (PBMCs) from two group patients were extracted and cultivated. The calculation of the Treg/Th17 ratio and quantitative analysis of the Treg and Th17 cell frequencies were performed through flow cytometry. Real-time fluorescence quantitative polymerase chain reaction (RT-PCR) was executed for the quantitative mRNA detection of the fork head-winged helix transcription factor (Foxp3) and the retinoic acid-related orphan nuclear receptor C (RORC) in PBMCs. Enzyme-linked immunosorbent assays were applied to measure the serum level of NLRP3, interleukin (IL)-10, IL-1β, IL-17A, IL-23, and transforming growth factor (TGF)-β1. Additionally, the connection between serum Treg/Th17 ratio and NLRP3 levels was analyzed using the Pearson correlation coefficient. Results: The baseline parameters, including sex, age, or blood biochemical indices had no difference in both groups (p > 0.05). The CAD group showed higher Th17 cell frequency, lower Treg cell frequency, and a lower Treg/Th17 ratio when compared to the control (p < 0.05). Consistent with the variation in the T-cell subset ratio, in patients with atherosclerosis, the Th17-cell-related transcription factor RORC showed a markedly higher mRNA level (p < 0.05), conversely, the mRNA expression of the Treg cell-related transcription factor Foxp3 was notably reduced (p < 0.05). Similarly, the serum levels of NLRP3, IL-17A, IL-1, and IL-23 were significantly enhanced in CAD group but IL-10 and TGF-β1 were reduced (p < 0.05). Additionally, a negative correlation was found between NLRP3 and the Treg/Th17 ratio (r = –0.69, p < 0.001). Conclusions: Due to the potential impact on the serum Treg/Th17 ratio, NLRP3 may act as an aggravator in the onset and progression of atherosclerotic disease