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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2006.03.021 Byline: Erdem Bangi, Kristi Wharton Keywords: BMP signaling; Dpp; Gbb; Tkv; BMP type I receptor; Wing imaginal disc; Morphogen Abstract: Morphogen gradients ensure the specification of different cell fates by dividing initially unpatterned cellular fields into distinct domains of gene expression. It is becoming clear that such gradients are not always simple concentration gradients of a single morphogen; however, the underlying mechanism of generating an activity gradient is poorly understood. Our data indicate that the relative contributions of two BMP ligands, Gbb and Dpp, to patterning the wing imaginal disc along its A/P axis, change as a function of distance from the ligand source. Gbb acts over a long distance to establish BMP target gene boundaries and a variety of cell fates throughout the wing disc, while Dpp functions at a shorter range. On its own, Dpp is not sufficient to mediate the low-threshold responses at the end points of the activity gradient, a function that Gbb fulfills. Given that both ligands signal through the Tkv type I receptor to activate the same downstream effector, Mad, the difference in their effective ranges must reflect an inherent difference in the ligands themselves, influencing how they interact with other molecules. The existence of related ligands with different functional ranges may represent a conserved mechanism used in different species to generate robust long range activity gradients. Author Affiliation: Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912, USA Article History: Received 20 January 2006; Revised 6 March 2006; Accepted 15 March 2006

• Hybrid model is developed for lab-scale production of β -carotene. • Neural ODEs are used to build a universal differential equation-based hybrid model. • Prior knowledge about the process is incorporated in the training of the model. • UDE-based hybrid model shows superior accuracy compared to existing kinetic model. β -Carotene has a positive impact on human health as a precursor of vitamin A. Building a kinetic model for its production using Saccharomyces cerevisiae in a batch fermentation process is challenging as it is difficult to quantify all the complex phenomena within the process. Any knowledge gap in the kinetic model can be reduced by utilizing data. Therefore, in this work, a hybrid model is built using the universal differential equations (UDEs) approach for accurately approximating the unknown dynamics of the process and thereby, increasing the overall accuracy of the model. In UDE approach, a neural ordinary differential equation that approximates the derivatives of the previously unknown dynamics of the batch fermentation process is integrated with the ODEs of its kinetic model to give a hybrid model with superior accuracy. Additionally, prior knowledge about the process is incorporated during the hybrid model training to ensure faster convergence of its parameters. [ABSTRACT FROM AUTHOR]

The purposes of this study were to determine why chronic obstructive pulmonary disease (COPD) is associated with heart failure (HF). Specific objectives included whether COPD is associated with myocardial fibrosis, whether myocardial fibrosis is associated with hospitalization for HF and death in COPD, and whether COPD and smoking are associated with myocardial inflammation. COPD is associated with HF independent of shared risk factors. The underlying pathophysiological mechanism is unknown. A prospective, multicenter, longitudinal cohort study of 572 patients undergoing cardiac magnetic resonance (CMR), including 450 patients with COPD and 122 age- and sex-matched patients with a median: 726 days (interquartile range: 492 to 1,160 days) follow-up. Multivariate analysis was used to examine the relationship between COPD and myocardial fibrosis, measured using cardiac magnetic resonance (CMR). Cox regression analysis was used to examine the relationship between myocardial fibrosis and outcomes; the primary endpoint was composite of hospitalizations for HF or all-cause mortality; secondary endpoints included hospitalizations for HF and all-cause mortality. Fifteen patients with COPD, 15 current smokers, and 15 healthy volunteers underwent evaluation for myocardial inflammation, including ultrasmall superparamagnetic particles of iron oxide CMR. COPD was independently associated with myocardial fibrosis (p < 0.001). Myocardial fibrosis was independently associated with the primary outcome (hazard ratio [HR]: 1.14; 95% confidence interval [CI]: 1.08 to 1.20; p < 0.001), hospitalization for HF (HR: 1.25 [95% CI: 1.14 to 1.36]); p < 0.001), and all-cause mortality. Myocardial fibrosis was associated with outcome measurements more strongly than any other variable. Acute and stable COPD were associated with myocardial inflammation. The associations between COPD, myocardial inflammation and myocardial fibrosis, and the independent prognostic value of myocardial fibrosis elucidate a potential pathophysiological link between COPD and HF. [Display omitted] [ABSTRACT FROM AUTHOR]

Introduction: The objective of this research was to analyze the effect of orthodontic treatment with maxillary permanent first molar extraction on the occlusal stress distribution and displacement in the human skull.Methods: A 3-dimensional finite element model was constructed on the basis of a computed tomography scan, and it was used as the pretreatment model. The software used for geometric modeling was Solid Works (Dassault Systèmes, Paris, France). For the extraction model, the maxillary permanent first molar was removed, followed by a repositioning of the anterior and posterior segments to create a space closure model. Stress distribution was evaluated under the simulation of 1000 N for occlusal forces and 400 N for masseter muscle force.Results: The highest von Mises stress was observed at the zygomatic process of the temporal bone across all 3 models (25 MPa), whereas stress at the pterygomaxillary suture area was almost 50% less. However, the stress in the pterygomaxillary suture area was lowest in the extraction model (18%) and space closure (30%). Stress in the zygomatic process of the frontal bone and frontal process of the maxilla increased from pretreatment to extraction model followed by space closure model.Conclusions: The occlusal forces were transferred through maxillonasal, maxillozygomatic, and maxillopterygoid stress trajectories. The mesial displacement of the molars may weaken the role of maxillopterygoid stress trajectory while strengthening the role of maxillonasal stress trajectory. [ABSTRACT FROM AUTHOR]

Cellular senescence is a conserved biological process that plays a crucial and context-dependent role in cancer. The highly heterogeneous and dynamic nature of senescent cells and their small numbers in tissues make in vivo mechanistic studies of senescence challenging. As a result, how multiple senescence-inducing signals are integrated in vivo to drive senescence in only a small number of cells is unclear. Here, we identify cells that exhibit multiple features of senescence in a Drosophila model of intestinal transformation, which emerge in response to concurrent activation of AKT, JNK, and DNA damage signaling within transformed tissue. Eliminating senescent cells, genetically or by treatment with senolytic compounds, reduces overgrowth and improves survival. We find that senescent cells promote tumorigenesis by recruiting Drosophila macrophages to the transformed tissue, which results in non-autonomous activation of JNK signaling. These findings identify senescent cell-macrophage interactions as an important driver of epithelial transformation. [Display omitted] • Senescent cells promote tumorigenesis in the Drosophila larval hindgut • Crosstalk among AKT, DDR, and JNK pathways drives senescence • Senescent cells cooperate with hemocytes they recruit to drive tumorigenesis • Hemocytes play a context-dependent, pro-tumorigenic role via biphasic JNK activation Datta and Bangi identify cells that exhibit multiple features of senescence in a Drosophila model of intestinal tumorigenesis. They show that senescent cells promote tumorigenesis by recruiting Drosophila macrophages to the transformed tissue, which then drives non-autonomous activation of JNK signaling in transformed cells. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Taibah University Medical Sciences is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Most epithelial tissues are maintained by stem cells that produce the different cell lineages required for proper tissue function. Constant communication between different cell types ensures precise regulation of stem cell behavior and cell fate decisions. These cell-cell interactions are often disrupted during tumorigenesis, but mechanisms by which they are co-opted to support tumor growth in different genetic contexts are poorly understood. Here, we introduce PromoterSwitch, a genetic platform we established to generate large, transformed clones derived from individual adult Drosophila intestinal stem/progenitor cells. We show that cancer-driving genetic alterations representing common colon tumor genome landscapes disrupt cell fate decisions within transformed tissue and result in the emergence of abnormal cell fates. We also show that transformed enteroendocrine cells, a differentiated, hormone-secreting cell lineage, support tumor growth by regulating intestinal stem cell proliferation through multiple genotype-dependent mechanisms, which represent potential vulnerabilities that could be exploited for therapy. [Display omitted] • PromoterSwitch (PS) allows more refined genetic manipulations in Drosophila • Cancer-driving genetic alterations disrupt cell fate decisions in the intestine • Transformed enteroendocrine cells (EEs) promote intestinal transformation • The EE hormone Tachykinin supports tumorigenesis through genotype-dependent mechanisms Quintero and Bangi use a genetic tool to show that cancer-driving genetic alterations disrupt cell fate decisions in the adult fly intestine, resulting in tumor-like growths that capture the cell-type heterogeneity of cancer. They also identify a tumor-promoting role for hormone-secreting enteroendocrine cells mediated by multiple genotype-dependent mechanisms. [ABSTRACT FROM AUTHOR]

In this paper two types of fractal antennas are designed, one by superimposing Hilbert curve on Minkowski curve known as Hilbert Minkowski Antenna (HMA) and other by superimposing Minkowski curve on Hilbert curve known as Minkowski Hilbert Antenna (MHA). Both antennas are compared in terms of performance parameters like gain, S 11 (dB), radiation pattern, current distribution and VSWR at all resonant frequencies. Both antennas are designed using HFSS software. FR4 material is used as a substrate material. Prototype of both antennas are designed, fabricated and tested at Vector Network Analyzer (VNA). It is found that Hilbert Minkowski Antenna has better performance in terms of Gain while Minkowski Hilbert Antenna is better in terms of number of frequency bands. A comparison between the characteristics of individual Hilbert and Minkowski curve based antennas is done with the characteristics of hybridized (MHA and HMA) antennas. It comes out that MHA and HMA have more number of frequency bands than individual Hilbert and Minkowski curve based antennas. A comparison has also been done between simulated and measured results of both antennas. Simulated and measured results for both the antennas are in agreement with each other. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Taibah University Medical Sciences is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: In this work, sulfur-doped mesoporous TiO2 films were formed by a chemical solution deposition technique to investigate their structure and electrical conductivity. Phase formation and crystallization of TiO2 was retarded and the optical band gap was reduced due to the presence of the sulfur dopants. As a result, enhancements in the microstructural stability and electrical conductivity of mesoporous TiO2 could be obtained by sulfur doping. [Copyright &y& Elsevier]

Abstract: This paper presents experimental work on the fracture toughness of fiber reinforced high-strength concrete subjected to high temperatures. Bending and fracture energy tests were conducted during and after cooling (i.e. hot and residual tests). It was observed that bending strength for the residual tests is higher than that for the hot tests because of the effect of tensile stresses arising in concrete which occurs in the hot tests but does not occur in the residual tests. Also it was observed that fracture toughness of steel fiber reinforced high-strength concrete in the hot tests is lower than that in the residual tests. However, steel fiber reinforcement is efficient in maintaining bending strength, and is more importantly effective in improving fracture toughness of high-strength concrete during and after cooling. Thus, the hot test should be conducted for evaluating mechanical properties of high-strength concrete due to its severity compared to the residual test. [Copyright &y& Elsevier]

Abstract: In this study, high surface area nanostructured zirconia powders were synthesized by a simple surface chemical modification method. Zirconia gels were prepared by the hydrolysis and condensation of zirconium n-propoxide in n-propanol using deionized water and nitric acid (1mM). The hydrolysis water used in the sol–gel process has the exceptional ability to tailor the nanostructural formation and hence, the textural properties of the final powder. Moreover, surface chemical modification facilitates the spring back effect in zirconia gels and helps to sustain the textural properties of the final product after ambient pressure drying. The zirconia powders were characterized by X-ray diffraction, N2 adsorption–desorption analysis, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric differential thermal analysis. The as-synthesized nanostructured zirconia powders had a large BET surface area of 354m2/g, a pore volume of 0.448cm3/g, and an average pore size of 57Å. As a result, they can be applied as catalysts in many fields. [Copyright &y& Elsevier]

Abstract: Interest in improving the optical transmission of sodium silicate-based aerogels by ambient pressure drying led to the synthesis of aerogels using a two-step sol–gel process. To produce optically transparent silica aerogel granules, NH4F (1 M) and HCl (4 M) were used as hydrolyzing and condensation catalysts, respectively. The silica aerogels were characterized by their bulk density, porosity (%), contact angle and thermal conductivity. Optical transmission of as synthesized aerogels was studied by comparing the photos of aerogel granules. Scanning electron microscopic study showed the presence of fractal structures in these aerogels. The degree of transparency in two step sol–gel process-based aerogels is higher than the conventional single step aerogels. The N2 adsorption–desorption analysis depicts that the two step sol–gel based aerogels have large surface areas. Optically transparent silica aerogels with a low density of ∼0.125 g/cc, low thermal conductivity of ∼0.128 W/mK and higher Brunauer, Emmett, and Teller surface area of ∼425 m2/g were obtained by using NH4F (1 M), HCl (4 M), and a molar ratio of Na2SiO3::H2O::trimethylchlorosilane of 1::146.67::9.46. The aerogels retained their hydrophobicity up to 500 °C. [Copyright &y& Elsevier]

Abstract: The experimental results on the improvement in optical and physical properties of TEOS based aerogels using acetonitrile via ambient pressure drying are reported herein. Silica gels were prepared by a two step sol–gel process using hydrochloric acid (HCl) as an acid catalyst and tertrabutyl ammonium fluoride (TBAF) as a base catalyst. Acetonitrile acts as a strong diluting solvent in the preparation of silica sol which considerably lowers the density and improves the optical transmission of silica aerogels. To study the effect of acetonitrile on the properties of TEOS based aerogels, acetonitrile::TEOS molar ratio was varied from 1.09 to 5.45. Optical transmission study of these aerogels was carried out by comparing the photos of aerogel granules. Optically transparent silica aerogels with low density (0.065g/cc) as well as low thermal conductivity (0.068W/mK) were successfully prepared using 1×10−3 M HCl, 0.1M TBAF and TEOS::MeOH::H2O(A)::H2O(B)::Acetonitrile::TMCS molar ratio at 1::16.75::3.5:2.5::1.69::0.88 respectively by ambient pressure drying method. [Copyright &y& Elsevier]

Abstract: This paper presents results of an experimental and statistical study which investigates the effect of fibre type and geometry on the amount of maximum pore pressures measured at different depths in fibre-reinforced high strength concrete (HSC) exposed to elevated temperatures. Polypropylene, polyvinyl alcohol and steel fibres of varying lengths and diameters were used. Pore pressure measurements showed that addition of organic fibres regardless of the type significantly contributes to pore pressure reduction in heated HSC. Polypropylene fibres were more effective in mitigating maximum pore pressure development compared to polyvinyl alcohol fibres while steel fibres had a slightly low effect. Longer organic fibres of length 12mm with smaller diameters of 18μm showed better performance than shorter ones of length 6mm with larger diameters of 28 and 40μm. Based on experimental observations and using statistical analysis, a relationship to predict maximum pore pressures in heated concrete was developed. [Copyright &y& Elsevier]

Abstract: The present experimental work investigates the build-up of pore pressure at different depths of High Strength Concrete (HSC) and Hybrid-Fibre-Reinforced High Strength Concrete (HFRHSC) when exposed to different heating rates. First, the effect of the measurement technique on maximum pore pressures measured was evaluated. The pressure measurement technique which utilised a sintered metal and silicon oil was found to be the most effective technique for pore pressure measurement. Pore pressure measurements carried out showed that addition of polypropylene fibres is very effective in mitigation of spalling and build-up of pore pressure inside heated HSC. Addition of steel fibres plays some role in pore pressure reduction at relatively higher pressures in deeper regions of concrete during fast heating. Pore pressure development is highly influenced by the rate of heating with fast heating leading to higher pore pressures in the deeper regions of concrete compared to slow heating. [Copyright &y& Elsevier]

Abstract: Water is one of the most affecting chemicals that can cause damage to the solid surface. To protect the surface due to the action of water, the surface should be made hydrophobic. In the present study, the improvement in hydrophobicity of silica films using metal acetylacetonate (M-acac) by employing heat treatment to methyltrimethoxy silane (MTMS) based silica coatings is reported as a novel attempt. Instead of following the established trends of the surface derivatization or co-precursor method, iron acetylacetonate Fe(acac)3, copper acetylacetonate Cu(acac)2 and heat treatment were used to incorporate hydrophobicity with silica coatings. As M-acac is readily soluble in organic solvents, Fe(acac)3 and Cu(acac)2 were dissolved in methanol (MeOH) and their concentration was varied from 0 to 0.025M. The coating solution was prepared by optimizing molar ratio of MTMS:MeOH:basic H2O to 1:7.15:6.34, respectively. Gelation time (t g) for Cu(acac)2 containing silica sol and that containing Fe(acac)3 were noted to be 30 and 55min, respectively. The substrates were taken out after gelation and heat treated at 150°C for 2h. The heat treated films showed a dramatic increase in the static water contact angle from 82° to as high as 142°. [ABSTRACT FROM AUTHOR]

Abstract: The experimental results on the “reduction in the processing time of doped sodium silicate based ambient pressure dried aerogels using shaker”, are reported. Shaking the hydrogels in the shaker in presence of distilled water helps in the removal of sodium salt and reduces the processing time of the aerogels. In addition, doping the gels enormously helps in the improvement of strength and thermal insulation property of the aerogels. Hence, the present paper deals with the study of the effects of shaking speed and shaking period of the granular gels, and doping the gels with titanium dioxide powder (TiO2) on the physical properties of the aerogels. The aerogels have been characterized by bulk density, volume shrinkage (%), porosity (%) and thermal conductivity. The quantitative analysis of hydrophobicity was done by measuring the contact angle of water on the surface of aerogel. The microstructural and elemental analyses studies were carried out using transmission electron microscopy (TEM), energy dispersive analysis by X-ray (EDAX) and fourier transform infrared (FTIR) spectroscopy. The pore volume and surface area of the aerogels were measured using N2 adsorption–desorption BET surface analyzer. The thermal stability of the aerogels was checked by thermogravimetric and differential thermal analyses (TGA–DTA). Silica aerogels with low density ∼0.047g/cc and low thermal conductivity ∼0.057W/mK have been obtained by shaking the gels at the speed of 150RPM for 4h using the molar ratio of Na2SiO3:H2O:TiO2:Citric acid:TMCS at 1:146.67:6×10−5:0.54:9.46, respectively. The shaking of the wet gels in a shaker reduces the processing time of the aerogels from 4 to 2days. These aerogels can be used as thermal insulating materials in ovens, refrigerators and related systems. [Copyright &y& Elsevier]

Three new unstable metabolites, (6E,10Z)-2′-O-methylmyxalamide D (1), 2′-O-methylmyxalamide D (2) and (6E)-2′-O-methylmyxalamide D (3) were isolated from the myxobacterium Cystobacter fuscus. The planar structures were elucidated by spectroscopic analyses to be geometrical isomers of a polyene amide related to a myxobacterial metabolite, myxalamide D (4). Their absolute stereochemistry was determined by synthesis of degradation products. Antifungal activities of 1–3 as well as their acetates were evaluated against the phythopathogenic fungus Phythopthora capsici. [Copyright &y& Elsevier]

• Deep reinforcement learning (DRL) controller is designed for hydraulic fracturing. • The uniform proppant concentration in the fracture is achieved. • PCA is used for dimensionality reduction of DRL state. • Transfer learning is used to quicken the learning process. Hydraulic fracturing is a technique to extract oil and gas from shale formations, and obtaining a uniform proppant concentration along the fracture is key to its productivity. Recently, various model predictive control schemes have been proposed to achieve this objective. But such controllers require an accurate and computationally efficient model which is difficult to obtain given the complexity of the process and uncertainties in the rock formation properties. In this article, we design a model-free data-based reinforcement learning controller which learns an optimal control policy through interactions with the process. Deep reinforcement learning (DRL) controller is based on the Deep Deterministic Policy Gradient algorithm that combines Deep-Q-network with actor-critic framework. Additionally, we utilize dimensionality reduction and transfer learning to quicken the learning process. We show that the controller learns an optimal policy to obtain uniform proppant concentration despite the complex nature of the process while satisfying various input constraints. [ABSTRACT FROM AUTHOR]

• A non-equilibrium LNG tank model is developed based on the vapor–liquid film model. • A reduced-order model is developed using the data from the proposed tank model. • An MPC system is proposed to control the tank pressure using the ROM. • An offset-free MPC system is designed to overcome the plant-model mismatch. • The control performance is improved when the offset-free MPC is applied. Due to tightened regulations on sulfur oxide (SO x) and nitrogen oxide (NO x) emissions, especially, in the ocean industry, liquefied natural gas (LNG) is becoming more important as an eco-friendly fuel source because of its extremely low SO x and NO x emissions. However, since LNG is usually stored at below its boiling temperature (- 160 ° C) and slightly above the atmospheric pressure, the invasion of natural heat causing evaporation of LNG is inevitable even with proper insulation. This evaporated LNG called boil-off gas (BOG) accumulates inside the tank, and without proper venting, the pressure inside the tank will build up and eventually reach the maximum allowable working pressure (MAWP) of the storage tank. The violation of this threshold will lead to serious consequences. Therefore, safe control of storage tank pressure is critical to its safe operation. In this paper, we propose to use a model predictive control (MPC) system to regulate the LNG tank pressure. Firstly, a dynamic model of the LNG storage tank is developed using the film evaporation theory. Secondly, a reduced-order model is developed using the N4SID algorithm. Finally, the offset-free MPC system scheme is applied to control the tank pressure. For demonstrating the performance of the offset-free MPC system in unnatural circumstances, a fire around the tank is applied. The results show that the offset-free MPC system is able to regulate the pressure even when a fire accident occurs despite the plant-model mismatch in such conditions. [ABSTRACT FROM AUTHOR]

• Integration of deep neural networks with first principles for hybrid modeling. • Deep neural networks are trained using Levenberg–Marquardt algorithm. • Application of deep hybrid modeling framework for hydraulic fracturing. Process modeling began with the use of first principles resulting in 'white-box' models which are complex but accurately explain the dynamics of the process. Recently, there has been tremendous interest towards data-based modeling as the resultant 'black-box' models are simple, and easy to construct, but their accuracy is highly dependent on the nature and amount of training data used. In order to balance the advantages and disadvantages of 'white-box' and 'black-box' models, we propose a hybrid model that integrates first principles with a deep neural network, and applied it to hydraulic fracturing process. The unknown process parameters in the hydraulic fracturing process are predicted by the deep neural network and then utilized by the first principles model in order to calculate the hybrid model outputs. This hybrid model is easier to analyze, interpret, and extrapolate compared to a 'black-box' model, and has higher accuracy compared to the first principles model. [ABSTRACT FROM AUTHOR]

• The effect of SAP content on the tensile properties of UHPC was investigated. • The pseudo-strain hardening response of UHPC was evaluated by using micromechanical principle. • The effect of SAP content on autogenous shrinkage and drying shrinkage of UHPC was study. • The change in strain field and the evolution of cracks on the surface of dog bone specimens were monitored using digital image correlation (DIC) technique. Extensive studies have focused on superabsorbent polymer (SAP) as an internal curing admixture to reduce the autogenous shrinkage of ultra-high performance concrete (UHPC). However, studies on the effect of SAP content on the tensile properties of UHPC are still limited. As we all know, tensile performance of UHPC is an aspect that cannot be ignored. Therefore, this paper investigates the effect of SAP content on the shrinkage and tensile properties of UHPC. First, according to mercury intrusion porosimetry (MIP) analyses, the moderate addition of SAP can refine the pore structure of matrix due to its internal curing effect. However, excess SAP brought more space filled with capillary water, thus increasing the porosity of matrix. The results of shrinkage test showed that the autogenous shrinkage of UHPC decreased first and then increased with the increase in SAP content. While the drying shrinkage of UHPC increased when SAP content increased. When 0.15% SAP was added, the 7 days autogenous shrinkage and 28 days total shrinkage of UHPC were the lowest, 51.3% and 30.1% lower respectively than those of UHPC without SAP. In addition, the moderate incorporation of SAP improved the tensile properties. Since the internal curing effect of SAP promoted the hydration of expand agents (EA) and cement, the microstructure of matrix became denser, enhancing the bond between fibers and matrix. Thus, the tensile strength of UHPC was improved. However, excess SAP have negative effect on the tensile strength due to the negative effect on pore structure. Furthermore, the tensile strain capacity of UHPC increased first and then decreased with the increase in SAP content. Finally, the micromechanical principle was proven to be a feasible method to evaluate tensile strain-hardening behaviors of UHPC. The trend of pseudo-strain-hardening (PSH) index and tensile strain capacity of specimen remained consistent. Additionally, when the ratio of maximum fiber bridging stress and matrix tensile cracking strength of UHPC was more than 1.1 rathan than 1.3, which was required in the filed of engineering cementitious composites (ECC), UHPCs exhibited obvious strain-hardening response. This indicated that the adjustment of the strength criterion in the micromechanical principle will be the key to its effective and reasonable evaluation of the tensile strain-hardening response of UHPC. [ABSTRACT FROM AUTHOR]

• The design approach of UHP-ECC was comprehensively reviewed. • The mechanical properties of UHP-ECC were systematically discussed. • Cost-performance evaluation on the mixture proportion of UHP-ECC was performed. Ultra-high performance engineered cementitious composite (UHP-ECC) is gaining significant interest among civil engineering researchers, owing to its excellent mechanical performance. This review is carried out to systematically summarize the design approach and fundamental factors influencing the mechanical properties of UHP-ECC, specifically the fiber parameters, water-binder ratio, nanomaterials, mineral admixtures, cyclic load, and strain rate. Besides, shrinkage performance and shrinkage mitigation approach of UHP-ECC are also discussed in this paper. Finally, the structural application of UHP-ECC is summarized. Based on the Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) method, the economic evaluation of the mixture proportion of current available UHP-ECCs is conducted to suggest the mixture proportions for the design of highly cost-effective UHP-ECC. [ABSTRACT FROM AUTHOR]

• The incorporation of superabsorbent polymer (SAP) and united expansion agent (UEA) could effectively mitigate the autogenous shrinkage. • The inclusion of SAP reduced the fracture toughness by increasing the matrix porosity, thus improving the multiple cracking and strain-hardening behavior of UHP-ECC. • Pseudo strain hardening index of each specimen was conducted to explain the effect of incorporation of SAP and UEA on the tensile properties of UHP-ECC. Ultra-high performance engineered cementitious composites (UHP-ECC) had received extensive attention in recent years in material as well as the field of structural rehabilitation and strengthening due to its excellent mechanical properties, such as high strength and high ductility. However, the high shrinkage is one of the bottlenecks limiting widespread engineering application of UHP-ECC. In this paper, superabsorbent polymers (SAP) and United expansion agent (UEA) were introduced to mitigate UHP-ECC shrinkage. And the effect of different amounts of SAP with UEA on the shrinkage and tensile properties of UHP-ECC are investigate. Results indicate that the incorporation of SAP and UEA can effectively mitigate the autogenous shrinkage, and the autogenous shrinkage decreased with the increasing SAP dosage; however, drying shrinkage had the opposite trend. The incorporation of SAP and UEA improved the tensile ductility of UHP-ECC. The inclusion of SAP reduced the fracture toughness by increasing the matrix porosity, which produced more micro-cracking sources, thus improving the multiple cracking and strain-hardening behaviors of UHP-ECC. Conversely, the incorporation of SAP decreased the fiber/matrix interaction as well as decreasing the effective number of polyethylene (PE) fibers in the cross-section, thus reducing the tensile strength. Finally, pseudo strain hardening index of each specimen was conducted to analyze the effect of SAP with UEA on the tensile properties of UHP-ECC. [ABSTRACT FROM AUTHOR]

• The influence of coarse aggregate on the workability, compressive, tensile, flexural properties, elastic modulus, durability, high-temperature performance, and shrinkage of UHPC, are reviewed. • The recommendations on the study of compression constitutive properties of UHPC containing coarse aggregate are given. • The elastic modulus prediction equations of UHPC with coarse aggregate are summarized. • Various applications of UHPC with coarse aggregate are introduced. • UHPC with coarse aggregate performance is evaluated by radar chart, and a performance-based method for designing UHPC with coarse aggregate mixtures is proposed. Ultra-high-performance concrete (UHPC) is a distinguishing material used in new construction and in conjunction with conventional concrete. However, some issues limit its broader applicability, such as high autogenous shrinkage, high cost, and insufficient elastic modulus increase compared with the normal strength concrete. Therefore, this paper reviews the key properties of UHPC containing coarse aggregate – added as a novel ingredient to the UHPC matrix to solve the issues mentioned above. This review covers the following aspects: (1) the influence on workability and mechanical properties (including compressive, tensile, flexural properties, and elastic modulus); (2) the recommendations on the study of compression constitutive properties of UHPC containing coarse aggregate (UHPC-CA); (3) the elastic modulus prediction; (4) the durability, high-temperature performance, and shrinkage of UHPC-CA; (5) the successful structural applications; and (6) UHPC-CA performance radar chart, and a design method based on performance. The results show that the introduction of coarse aggregate has significant effects on the mechanical performance of UHPC. For compressive properties, there is an optimal coarse aggregate content for each mix proportion; For tensile and flexural properties, coarse aggregate has negative effects mainly due to the decline of efficiency coefficient of fibers; On the contrary, for elastic modulus, coarse aggregate has positive effect attribute to its high rigidity. Besides, the durability, including the resistance to chloride ion penetration, salt crystallization and frost heaving, and high temperature performance and shrinkage, of UHPC-CA is superior. This review is expected to give an overview of the research field and provide guidance for future research. [ABSTRACT FROM AUTHOR]