Effect of right internal mammary artery versus radial artery as a second graft vessel in coronary artery bypass grafting on postoperative wound infection in patients: A meta-analysis.

Few studies have shown that radial artery (RA), which is used as a secondary arterial graft, offers superior results compared with right internal thoracic artery (RIMA) in coronary artery bypass grafting (CABG). In a meta-analysis of observational studies starting in 2023, we looked at the effect of re-operation on postoperative infection and haemorrhage in CABG with RA vs. RIMA. The electronic database up to October 2023 was examined in the course of the research. Analysis was carried out on the clinical trials of postoperative wound infections and haemorrhage re-surgery. Among 912 trials associated with CABG, we selected 8 trials to be included in the final data analysis. The main results were secondary wound infection and re-operation after surgery. The odds ratios (OR) and confidence intervals (CIs) were computed on the basis of a randomized or fixed-effect model of wound infection and re-operation. Seven trials showed a significant reduction in the risk of wound infection in RA treated as a secondary artery transplant compared with RIMA (OR, 1.60; 95% CI, 1.03, 2.47 p = 0.04); Four trials showed that RIMA was not significantly different from RA in the rate of re-operation for postoperative bleeding (OR, 1.31; 95% CI, 0.60, 2.88 p = 0.50). In CABG, RA is used as a secondary arterial conduit graft to lower the risk of wound infection in CABG patients.

Sustainable assessment and synergism of ceramic powder and steel slag in iron ore tailings-based concrete.

Solid waste management is a critical issue worldwide. Effectively utilizing these solid waste resources presents a viable solution. This study focuses on Iron ore tailings (IOTs), a solid waste generated during iron ore processing, which can be used as supplementary cementitious materials (SCMs) but have low reactivity, hindering their large-scale application in concrete production. To address this, ternary SCMs were prepared using ceramic powder (CP) and steel slag (SS) to enhance the performance of concrete incorporating IOTs. The study found that the synergistic effect of CP and SS significantly improved the compressive strength of concrete, with a notable increase of up to 21% compared to concrete with IOTs alone. Mercury intrusion porosimetry (MIP) and backscattering electron (BSE) analyses revealed that the ternary SCMs significantly optimized the characteristics of the interfacial transition zone (ITZ), which in turn enhanced the compressive properties of the concrete. This contributed to maintaining the structural integrity of the concrete, even amidst variations in the pore structure. Importantly, the incorporation of ternary SCMs led to a 23% reduction in carbon emissions, from 400.01 kg CO2/m3 to 307.48 kg CO2/m3, and elevated eco-strength efficiency from 0.1 to 0.14. The study highlights the role of multi-material synergy in developing composite SCMs systems, fostering the sustainable advancement of green building materials.

Development and Validation of a Prognosis-Prediction Signature for Patients with Lung Adenocarcinoma Based on 11 Telomere-Related Genes.

BACKGROUND: The occurrence and progression of lung cancer are correlated with telomeres and telomerase. Telomere length is reduced in the majority of tumors, including lung cancers. Telomere length variations have been associated with lung cancer risk and may serve as therapeutic targets as well as predictive biomarkers for lung cancer. Nevertheless, the effects of telomere-associated genes on lung cancer prognosis have not been thoroughly studied. We aim to investigate the relationship between telomere-associated genes and lung cancer prognosis. METHODS: The Cancer Genome Atlas and Genotype-Tissue Expression databases were used as training sets to build a predictive model. Three integrated Gene Expression Omnibus datasets served as validation sets. Using cluster consistency analysis and regression with the least absolute shrinkage and selection operator, we developed a telomere-related gene risk signature (TMGsig) based on 11 overall survival-related genes (RBBP8, PLK1, DSG2, HOXA7, ANAPC4, CSNK1E, SYAP1, ALDOA, PHF1, MUTYH, and PGS1). RESULTS: The results indicated a negative outcome for the high-risk score group. Immunological microenvironment and somatic mutations differed between the high- and low-risk groups. A statistically significant difference existed between the low-risk and high-risk groups in terms of the expression levels of B cells and CD4 cells, and the risk score was essentially inversely linked with immune cell expression. CONCLUSIONS: TMGsig can predict outcomes in patients with lung adenocarcinoma.

Effect of Aurora kinase B on polyploidy and decidualization in mouse uterus.

RESEARCH QUESTION: Decidualization is critical to the establishment of mouse normal pregnancy. The fibroblast-like stromal cells in the process form polyploid multinucleated cells. Aurora kinase B (Aurora B) has previously been shown to regulate polyploidy in various cells. However, whether Aurora B regulates the formation of decidual cell polyploidization and its regulatory mechanisms remain poorly understood. DESIGN: Establish decidualization model of mouse primary endometrial stromal cells in vitro. Construct pseudopregnancy mouse models and delayed-activation mouse models. Detect Aurora B and polyploidization related genes in mouse uteri treated by Aurora B specific inhibitor Barasertib and CPT. RESULTS: In this study, we found that Aurora B was strongly expressed in endometrial stromal cells after implantation. Additionally, Aurora B was remarkably up regulated in the stromal cells of oil-induced deciduomoa and in vitro decidualization. As an Aurora B specific inhibitor, Barasertib significantly inhibits the mRNA expression of Prl8a2, a marker of mouse decidualization. Furthermore, the protein levels of p-Plk1, Survivin and p-Cdk1 were inhibited by Barasertib. CPT-induced DNA damage suppressed Aurkb (encodes Aurora B) expression, thus resulting in polyploidization. CONCLUSION: Our data shows that Aurora B is expressed in decidual stromal cells of implantation sites and plays a key role for mouse decidualization. The protein of Plk1, Survivn, and Cdk1 may participate in formation of decidual cell polyploidization during mouse decidualization.

Predictive significance of lymphocyte level and neutrophil-to-lymphocyte ratio values during radiotherapy in cervical cancer treatment.

OBJECTIVE: The objective of this research was to analyze the prognostic significance of the minimum count of lymphocytes (LY) and the corresponding ratio of neutrophil-to-lymphocyte (NLR) in cervical cancer (CC) patients receiving radiotherapy. METHODS: We retrospectively collected data from 202 CC patients who received concurrent chemoradiotherapy or radiotherapy alone at our hospital. Statistical methods including the Kaplan-Meier method, log-rank test and the Cox proportional hazards model were included to examine survival differences and identify independent factors that may affect overall survival (OS) and progression-free survival (PFS). RESULTS: The research enrolled a total of 202 patients. Patients with higher LY levels and lower NLR values during radiotherapy had significantly better survival prognosis than those with lower LY levels and higher NLR values. Multivariate COX regression analysis revealed that FIGO stage I, pathological types of SqCC, absence of lymph node metastasis, concurrent chemoradiotherapy, higher LY levels during radiotherapy, and lower NLR values before radiotherapy were independently associated with poorer PFS. Similarly, FIGO stage I, absence of lymph node metastasis and lower NLR values during and before radiotherapy were independently linked with poorer OS. CONCLUSION: Minimum LY value and its corresponding NLR during radiotherapy serve as prognostic factors for CC.

Deep learning enables satellite-based monitoring of large populations of terrestrial mammals across heterogeneous landscape.

New satellite remote sensing and machine learning techniques offer untapped possibilities to monitor global biodiversity with unprecedented speed and precision. These efficiencies promise to reveal novel ecological insights at spatial scales which are germane to the management of populations and entire ecosystems. Here, we present a robust transferable deep learning pipeline to automatically locate and count large herds of migratory ungulates (wildebeest and zebra) in the Serengeti-Mara ecosystem using fine-resolution (38-50 cm) satellite imagery. The results achieve accurate detection of nearly 500,000 individuals across thousands of square kilometers and multiple habitat types, with an overall F1-score of 84.75% (Precision: 87.85%, Recall: 81.86%). This research demonstrates the capability of satellite remote sensing and machine learning techniques to automatically and accurately count very large populations of terrestrial mammals across a highly heterogeneous landscape. We also discuss the potential for satellite-derived species detections to advance basic understanding of animal behavior and ecology.

Effect of Iron Tailing Powder-Based Ternary Admixture on Acid Corrosion Resistance of Concrete.

Exposure of concrete to acidic environments can cause the degradation of concrete elements and seriously affect the durability of concrete. As solid wastes are produced during industrial activity, ITP (iron tailing powder), FA (fly ash), and LS (lithium slag) can be used as admixtures to produce concrete and improve its workability. This paper focuses on the preparation of concrete using a ternary mineral admixture system consisting of ITP, FA, and LS to investigate the acid erosion resistance of concrete in acetic acid solution at different cement replacement rates and different water-binder ratios. The tests were performed by compressive strength analysis, mass analysis, apparent deterioration analysis, and microstructure analysis by mercury intrusion porosimetry and scanning electron microscopy. The results show that when the water-binder ratio is certain and the cement replacement rate is greater than 16%; especially at 20%, the concrete shows strong resistance to acid erosion; when the cement replacement rate is certain and the water-binder ratio is less than 0.47; especially at 0.42, the concrete shows strong resistance to acid erosion. Microstructural analysis shows that the ternary mineral admixture system composed of ITP, FA, and LS promotes the formation of hydration products such as C-S-H and AFt, improves the compactness and compressive strength of concrete, and reduces the connected porosity of concrete, which can obtain good overall performance. In general, concrete prepared with a ternary mineral admixture system consisting of ITP, FA, and LS has better acid erosion resistance than ordinary concrete. The use of different kinds of solid waste powder to replace cement can effectively reduce carbon emissions and protect the environment.

Adoption of Ultrasound-guided Polymer Nanocarriers in Tumor Chemoradiotherapy and Oxidation Treatment.

The research was aimed at discussing the effectiveness of ultrasound-guided polymer nanocarriers in the clinical treatment of tumors by chemoradiotherapy and oxidation treatment. Twenty female Balb/cAnN (BALB/C) mice were selected as the research objects in the experiment. These mice were set up as tumor-bearing mice, and then ultrasound-guided polymers with different doses, including polyethylene glycol-poly 2-bromoethyl methacrylate (PEG-PBEMA) (Micelle group), free small molecules called l-ascorbyl palmitate (PA) (PA group), PA-micelle micellar particles (PA-Micelle group) prepared in the research, and phosphate buffer solution (PBS) (PBS group) were adopted. Besides, the growth of mice was recorded and compared after each operation. Meanwhile, different concentrations of PA-Micelle micellar particles and free small molecules of PA were added to the breast cancer cells of mice, and the concentration changes of glutathione (GSH) were detected to test the oxidation treatment ability of this method. According to the results of the experiment, the tumor volume of mice in the PA-Micelle group prepared in the research was the smallest followed by the PA group, and the tumor volume of mice in the Micelle group was the third smallest. The mice in the PBS group had the largest tumors among mice in all four groups. In oxidation treatment, the GSH concentration of mice in the PA-Micelle group was the lowest, while the GSH concentration of mice in the PA group was almost unchanged. The results of this experiment proved that the therapeutic effect of polymer nanocarriers in tumor chemotherapy and oxidation treatment was more significant than in traditional drug treatment.

OTX1 silencing suppresses ovarian cancer progression through inhibiting the JAK/STAT signaling.

BACKGROUND: The aim of our study was to investigate the roles and the underlying mechanisms of orthodenticle homolog 1 (OTX1) in ovarian cancer. METHODS: OTX1 expression was obtained from TCGA database. OTX1 expression in ovarian cancer cells was detected using qRT-PCR and western blot assay. The cell viability and proliferation was detected by CCK-8 and EdU assays. Cell invasion and migration were detected by transwell assay. Flow cytometry was utilized to determine cell apoptosis and cycle. In addition, western blot assay was used to detect the expression of cell cycle related protein (Cyclin D1 and p21), epithelial-mesenchymal transition (EMT) related protein (E-cadherin, N-cadherin, Vimentin, and Snail), apoptosis related protein (Bcl-2, Bax, and cleaved caspase-3), and JAK/STAT pathway related protein (p-JAK2, JAK2, STAT3, and p-STAT3). RESULTS: OTX1 was highly expressed in ovarian cancer tissues and cells. OTX1 silencing blocked the cell cycle and repressed cell viability, proliferation, invasion, and migration, while OTX1 silencing facilitated the apoptosis of OVCAR3 and Caov3 cells. OTX1 silencing increased the protein levels of p21, E-cadherin, Bax, and cleaved caspase-3, while the protein levels of Cyclin D1, Bcl-2, N-cadherin, Vimentin, and Snail were decreased by OTX1 silencing. Furthermore, OTX1 silencing suppressed the protein levels of p-JAK2/JAK2 and p-STAT3/STAT3 in OVCAR3 and Caov3 cells. Moreover, overexpression of OTX1 promoted cell proliferation and invasion and inhibited apoptosis in Caov3 cells, but AG490 (an inhibitor of JAK/STAT pathway) reversed the influences on cell biological behavior induced by overexpression of OTX1. CONCLUSIONS: OTX1 silencing repressed ovarian cancer cell proliferation, invasion, and migration and induced cell apoptosis, which might be involved in JAK/STAT signaling pathway. OTX1 may be considered as a novel therapeutic target for ovarian cancer.

Testicular macrophages are recruited during a narrow fetal time window and promote organ-specific developmental functions.

A growing body of evidence demonstrates that fetal-derived tissue-resident macrophages have developmental functions. It has been proposed that macrophages promote testicular functions, but which macrophage populations are involved is unclear. Previous studies showed that macrophages play critical roles in fetal testis morphogenesis and described two adult testicular macrophage populations, interstitial and peritubular. There has been debate regarding the hematopoietic origins of testicular macrophages and whether distinct macrophage populations promote specific testicular functions. Here our hematopoietic lineage-tracing studies in mice show that yolk-sac-derived macrophages comprise the earliest testicular macrophages, while fetal hematopoietic stem cells (HSCs) generate monocytes that colonize the gonad during a narrow time window in a Sertoli-cell-dependent manner and differentiate into adult testicular macrophages. Finally, we show that yolk-sac-derived versus HSC-derived macrophages have distinct functions during testis morphogenesis, while interstitial macrophages specifically promote adult Leydig cell steroidogenesis. Our findings provide insight into testicular macrophage origins and their tissue-specific roles.

Effect of Particle Size and Morphology of Siliceous Supplementary Cementitious Material on the Hydration and Autogenous Shrinkage of Blended Cement.

Supplementary cementitious material (SCM) plays an important role in blended cement, and the effect of the particle size and morphology of siliceous supplementary cementitious material on hydration should not be ignored. In this study, 0.5 h and 1 h of wet grinding was applied to pretreat iron ore tailing powder (TP), and the divergence in pozzolanic behavior and morphology were investigated. Then, the treated TPs were used to replace the 30% cement contents in preparing blended cementitious paste, and the impact mechanism of morphology on performance was studied emphatically. M, the autogenous shrinkages of pastes were tested. Finally, hydration reaction kinetics was carried out to explore the hydration behavior, while X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were used to characterize the hydration product properties, respectively. Meanwhile, microscopy intrusion porosimetry (MIP) was also carried out to characterize the pore structures of hardened specimens. Results indicated that wet grinding has a dramatic effect on particle size and morphology, but hardly affects the phase assemblages and pozzolanic reactivity of TP, while the particle shape of TP changes from sub-circular to clavate and, finally, back to sub-circular. The results of hydration reaction kinetics, representing the morphology of particles, had a significant effect on hydration rate and total heat, and compared with the sub-circle one, the clavated particle could inhibit the hydration procedure. With the increasing grinding time, the compressive strength of cementitious paste was increased from 17.37% to 55.73%, and the micro-pore structure became denser; however, the autogenous shrinkage increased.

Enumeration optimization of open pit production scheduling based on mobile capacity search domain.

The optimization of open pit mine production scheduling is not only a multistage decision-making problem but also involves space-time dynamic action among multiple factors, which makes it difficult to optimize production capacity, mining sequence, mining life, and other factors simultaneously in optimizing design. In addition, the production capacity is disorderly expanded, the calculation scale is large, and the optimization time is long. Therefore, this article designs a mobile capacity search domain method to improve computing efficiency without omitting the optimal production capacity. At the same time, taking the maximum net present value as the objective function, an enumeration method is used to optimize the possible paths in different capacity domains and calculate the infrastructure investment and facility idle cost required to meet the maximum production capacity on each possible path to control the disorderly expansion and violent fluctuation of production capacity. The research shows that the open pit mine production scheduling optimization algorithm proposed in this article can not only realize the simultaneous optimization of the three elements of production capacity, mining sequence, and mining life but also improve the computing efficiency by 200 times. Furthermore, the production capacity fluctuation is less than 1.4%. The mining life of the mine is extended by 13 years, and the overall economic benefit is increased by 18%.

Perivascular cells support folliculogenesis in the developing ovary.

Supporting cells of the ovary, termed granulosa cells, are essential for ovarian differentiation and oogenesis by providing a nurturing environment for oocyte maintenance and maturation. Granulosa cells are specified in the fetal and perinatal ovary, and sufficient numbers of granulosa cells are critical for the establishment of follicles and the oocyte reserve. Identifying the cellular source from which granulosa cells and their progenitors are derived is an integral part of efforts to understand basic ovarian biology and the etiology of female infertility. In particular, the contribution of mesenchymal cells, especially perivascular cells, to ovarian development is poorly understood but is likely to be a source of new information regarding ovarian function. Here we have identified a cell population in the fetal ovary, which is a Nestin-expressing perivascular cell type. Using lineage tracing and ex vivo organ culture methods, we determined that perivascular cells are multipotent progenitors that contribute to granulosa, thecal, and pericyte cell lineages in the ovary. Maintenance of these progenitors is dependent on ovarian vasculature, likely reliant on endothelial-mesenchymal Notch signaling interactions. Depletion of Nestin+ progenitors resulted in a disruption of granulosa cell specification and in an increased number of germ cell cysts that fail to break down, leading to polyovular ovarian follicles. These findings highlight a cell population in the ovary and uncover a key role for vasculature in ovarian differentiation, which may lead to insights into the origins of female gonad dysgenesis and infertility.

Synergistic removal of phosphorus and fluorine impurities in phosphogypsum by enzyme-induced modified microbially induced carbonate precipitation method.

Microbially induced carbonate precipitation (MICP) technology is difficult to be used for phosphogypsum (PG) treatment because the pH of PG is too low to be suitable for the growth of some bacteria. When acidophilus bacteria are used to treat PG, their low mineralization rate leads to low removal of the impurities. Based on the above problems, this study reports a new method that uses enzyme induced carbonate precipitation (EICP) modified acidophilus bacteria solution to remove phosphorus (P) and fluorine (F) in PG. Five kinds of mixtures of MICP and EICP (ME) were used to leach the PG column, and its mechanism was discussed. The results show that when the ratio of MICP to EICP is 2:1, the removal ratio of P and F is the highest, which reaches 72.87-74.92%. Compared with the single traditional bacillus solution or single acidophilic bacteria solution, the impurity removal ratio of the ME21 (MICP:EICP=2:1) mixture is increased by about 13%. The good acid resistance of the urease enzyme and acidophilic bacteria improves their growth and activity, thus increasing the biomineralization rate by about 22%. Additionally, the ME treatment is 30% cheaper than the traditional binder treatment. Therefore, this new treatment is a low-cost and environmentally friendly method.

Recycling of arsenic-containing biohydrometallurgy waste to produce a binder for cemented paste backfill: Co-treatment with oil shale residue.

The high cost of ordinary Portland cement (OPC) limits the broad usage of cemented paste backfill (CPB). Additionally, improper disposal of arsenic-containing biohydrometallurgy waste (BW) can cause tremendous pollution to the environment. Consequently, BW is used to prepare an alternative cementitious material for CPB in this study. The effect of calcined oil shale residue (COSR) on the binder's characteristics was studied. The reaction kinetics of the binder in the presence of COSR were studied via the isothermal calorimeter test and the Krstulovic-Dabic model; mechanical strength and hydration product modifications due to the addition of COSR were also investigated. The leaching of hazardous elements from the binder was also investigated. The results showed that adding COSR reduced the flowability of fresh slurry and early-age compressive strength; however, adding 20 wt% COSR resulted in the highest later age compressive strength, thereby reaching ∼43.65 MPa after 60 days. The compressive strength of the CPB sample using the COSR20 as a binder may reach ∼87% of the OPC-based CPB sample. Furthermore, the presence of COSR had no significant effect on the phase assembles but changed the amount of ettringite (AFt) and calcium silicate aluminate hydrate (C-A-S-H). The results of this study show that the prepared binder could be used as an alternative to OPC in CPB.

Study on Properties and Optimization of Ternary Auxiliary Cementing Materials for IOTs.

In order to control energy consumption and reduce pollution, the use of supplementary cementitious materials (SCMs) instead of cement to produce green cementitious materials can save energy, reduce emissions and achieve sustainable development. This study demonstrates the possibility of developing SCMs with iron tailings (IOTs), fly ash (FA) and ceramic powder (CP) ternary system, as well as the optimization and improvement scheme of gelation activation. The effects of activator dosage, mix ratio and substitution rate on mechanical properties of ternary SCMs system were investigated. The formation and evolution of hydration products were analyzed by differential thermogravimetric analysis (DTA) and scanning electron microscopy (SEM). The results of the study show that there is synergy in the system. The results show that there is synergy in the system and the hydration reaction is sufficient. At the substitution rate of 30%, the doping ratio of IOTs, CP and FA is 1:2:2 and the Ca(OH)2 is 0.6%, the strength reaches 39.9 MPa and the activity index is 91.5%, which can provide a basis for the application and more in-depth study of IOTs multi SCMs.

Application of Iron Tailings-Based Composite Supplementary Cementitious Materials (SCMs) in Green Concrete.

How to treat the iron tailings of mining solid waste with high value is an urgent problem on a global scale. In recent years, the application of iron tailings in the building materials industry has attracted the attention of many scholars. The conversion of iron tailings into green building materials helps achieve carbon neutrality and high-value utilization of solid waste, and promotes sustainable development. Although iron tailings have been extensively studied as supplementary cementitious materials, the performance of concrete is not ideal due to its low activity. In this study, the hybrid supplementary cementitious materials system was prepared by iron tailings, phosphorus slag, and steel slag, and the effects of supplementary cementitious materials type, iron tailings content, iron tailings grinding time, and supplementary cementitious materials content on concrete performance were studied. The compressive properties, iron tailings properties, pore structure, interfacial transition zone, and element distribution of hydration products of concrete were tested by compressive strength tests, X-ray Diffractometer (XRD), X-ray Photoelectron Spectroscopy (XPS), Mercury Intrusion Porosimetry (MIP), Backscattering Electron Tests (BSE), and Energy Dispersive Spectrometer (EDS). The results show that further grinding improves the iron tailings activity. There is a synergistic mechanism between steel slag and phosphorus slag in the composite supplementary cementitious materials, which overcomes the low activity defect of iron tailings and produces concrete with a compressive strength exceeding 40 MPa. The composite supplementary cementitious materials can optimize the interfacial transition zone of the concrete interface and reduce the calcium-silicon ratio of the hydration products. However, it will deteriorate the pore structure of the concrete matrix, cause part of the concrete matrix to be damaged and lead to a loss of compressive strength, and the loss is acceptable. This work broadens the methods of comprehensive utilization of iron tailings and also provides a reference for a more detailed understanding of the properties of iron tailings-based concrete.

Immune Cells as Critical Regulators of Steroidogenesis in the Testis and Beyond.

Steroidogenesis is an essential biological process for embryonic development, reproduction, and adult health. While specific glandular cells, such as Leydig cells in the testis, are traditionally known to be the principal players in steroid hormone production, there are other cell types that contribute to the process of steroidogenesis. In particular, immune cells are often an important component of the cellular niche that is required for the production of steroid hormones. For several decades, studies have reported that testicular macrophages and Leydig cells are intimately associated and exhibit a dependency on the other cell type for their proper development; however, the mechanisms that underlie the functional relationship between macrophages and Leydig cells are unclear. Beyond the testis, in certain instances immune cells themselves, such as certain types of lymphocytes, are capable of steroid hormone production, thus highlighting the complexity and diversity that underlie steroidogenesis. In this review we will describe how immune cells are critical regulators of steroidogenesis in the testis and in extra-glandular locations, as well as discuss how this area of research offers opportunities to uncover new insights into steroid hormone production.

Preparation and characterization of a new alkali-activated binder for superfine-tailings mine backfill.

Recently, the increasing of ultrafine-tailings increases the amount of ordinary Portland cement (OPC) in cemented paste backfill (CPB), which leads to the rise of CPB cost and carbon emission. As a result, it is necessary to develop alternative binders. The present work focuses on the preparation of a new binder, which is activated by a mixture of calcined quarry dust (CQD) and NaOH at a mass ratio of 1:1. The results indicated that CQD/NaOH was more effective than using NaOH or CQD alone in activating blast furnace slag (BFS) and also showed better performance than OPC. The compressive strength of the CPB samples using 10% CQD/NaOH was around 3.78 MPa after curing for 90 days, around 42% higher than the OPC-based CPB samples. The reaction products of CQD/NaOH-activated BFS consisted mainly of C-(A)-S-H, hydrotalcite like phases (Ht), and M-S-H. The generation of Ht phases lowered the Al incorporation into the structure of C-S-H, resulting in lower average Al/Si ratio and mean chain length.

Rheological and Mechanical Properties of High-Performance Fiber-Reinforced Cement Composites with a Low Water-Cement Ratio.

High-performance fiber-reinforced cement composites (HPFRCCs) have been widely used in structural engineering due to their excellent performance. With the trend of lightweight construction, these materials, which can be used in prefabricated components, are becoming more and more important. This study investigated the influence of the water-cement (w/c) ratio, within the 0.19-0.28 range, on the rheological and mechanical properties of HPFRCCs; the pore structure and microstructure were observed to evaluate its effect. An elastic modulus test showed that a smaller w/c ratio would result in a higher rigidity of the material. Both the yield shear stress and plastic viscosity decreased to significantly different degrees with an increasing w/c ratio; a decrease in the yield shear stress and plastic viscosity was conducive to air discharge from the composite and, hence, reduced the air content. Most of the internal pores had a diameter of 20-100 nm or larger than 200 nm, while the proportion of those with a diameter of 100-200 nm was relatively low. When the w/c ratio was below 0.22, the flexural and compressive strengths barely increased due to an increment in the number of larger pores (i.e., diameter >200 nm). The results showed that the yield shear stress, plastic viscosity, pore uniformity, and the number of pores with a diameter above 200 nm are the dominant factors affecting the HPFRCC performance at a low w/c ratio.