•A comprehensive review of the fundamental factors influencing the tensile properties of ECC was conducted.•The durability of ECC including the long-term tensile properties, the impact of high ...temperature, cyclic and fatigue loading was reviewed.•The future directions of ECC have been pointed out.
The high tensile strain capacity of engineered cementitious composites (ECC) is exceptional for cementitious material. In the present paper, a comprehensive review is conducted to summarize the fundamental information of factors that influence the tensile properties of ECC, specifically the fiber properties, specimen size and geometry, and strain rate. The extended durability of ECC, including the long-term tensile properties, the mechanical behaviors under the high temperature impact and the cyclic and fatigue loading, is also paid special attention. It is concluded that (1) fiber properties have a decisive effect on the tensile performance of ECC; (2) size and geometry effect exists in tensile test and needs further study; (3) high rate loading leads to a noticeable changes in the tensile properties of ECC; and (4) durability of tensile properties should be further investigated for the better application of ECC material.
The Asian monsoon variations under global temperature changes during the Pliocene are still debated. Here we use a sedimentary record of phytoliths (plant silica) from the Weihe Basin, central China, ...to explore the history of C
grasses and quantitatively reconstruct the Asian monsoon climate since the late Miocene. Our results show that C
grasses have been a dominant grassland component since ~11.0 Ma. A subsequent marked decrease in warm- and humid-adapted C
grasses and an increase in cool- and dry-adapted C
grasses occurred in the Pliocene, ~4.0 Ma; the phytolith-based quantitative reconstruction of mean annual precipitation marked a decrease from 800~1673 mm to 443~900 mm, indicating a reduction in Asian monsoon rainfall in the Pliocene. Our newly obtained records conflict with the hypothesis that the growth of the Tibetan Plateau strengthened the Asian monsoon rainfall. Nevertheless, they emphasize the importance of global temperature as a determinant of Pliocene Asian monsoon variations.
The land-based oil extraction activity has led to serious pollution of the soil. While microbes may play an important role in the remediation of contaminated soils, ecological effects of oil ...pollution on soil microbial relationships remain poorly understood. Here, typical contaminated soils and undisturbed soils from seven oilfields of China were investigated in terms of their physicochemical characteristics, indigenous microbial assemblages, bacterial co-occurrence patterns, and metabolic enzymes. Network visualization based on k-core decomposition illustrated that oil pollution reduced correlations between co-existing bacteria. The core genera were altered to those related with oil metabolism (Pseudarthrobacter, Alcanivorax, Sphingomonas, Chromohalobacter and Nocardioides). Under oil pollution pressure, the indigenous bacteria Gammaproteobacteria was domesticated as biomarker and the enzyme expression associated with the metabolism of toxic benzene, toluene, ethylbenzene, xylene and polycyclic aromatic hydrocarbons was enhanced. Functional pathways of xenobiotics biodegradation were also stimulated under oil contamination. Finally, twelve culturable hydrocarbon-degrading microbes were isolated from these polluted soils and classified into Stenotrophomonas, Delftia, Pseudomonas and Bacillus. These results show that the soil microbial communities are transformed under oil pollution stress, and also provide useful information for future bioremediation processes.
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•Ecological effects of soil oil contamination were revealed.•Oil-affected microbial communities were enriched with Gammaproteobacteria.•Petroleum contamination altered the soil bacterial co-occurrence pattern.•Oil stress stimulated the expression of BTEX and PAH-related metabolic enzymes.•Twelve hydrocarbon-degrading strains were isolated from oil-polluted soils.
A series of BaSr2Sc4O9 and Ce3+-doped BaSr2Sc4O9 phosphors were synthesized via the high temperature solid state reaction. Crystal structure information on BaSr2Sc4O9 is first refined using the ...Rietveld method based on the XRD data, and it is assigned to the trigonal system with the R3 space-group. The photoluminescence properties were investigated in detail, including the emission and excitation spectra, site occupation, decay lifetime, thermal quenching, and quantum efficiency. There are three Ba2+/Sr2+ sites and four Sc3+ sites in this structure. The Ce3+ ions in the 6-fold coordinated Sr2+/Ba2+ sites show a near-ultraviolet-blue emission with a peak at around 407 nm under ultraviolet excitation. The Ce3+ ions in Sc3+ sites exhibit a bright broad orange-red emission with the peak at around 615 nm under near-ultraviolet and blue excitation. The energy transfer process between the different sites is demonstrated based on the spectral analysis, theoretical calculation, and decay lifetime variation. Under excitation of 345 nm, the energy transfer phenomenon and distribution of activator ions lead to the invalidation of part of the Ce3+ ions, and then it causes a higher concentration quenching point. The participation of the energy transfer in the thermal quenching phenomenon causes the abnormal intensity variation, which is ascribed to the energy compensation by the increasing energy transfer efficiency at high temperature. The internal quantum efficiency is 45% under the 420 nm excitation wavelength. An excellent white light emitting diode lamp is obtained by fabricating BaSr2Sc4O9:Ce3+ with BAM:Eu2+, β-sialon:Eu2+, and a 395 nm GaN chip; its CIE coordinate (x, y), CCT, and Ra are (0.3708, 3463), 4023 K, and 84. These results reveal the correlation between energy transfer and luminescent property and provide a practical foundation to comprehend and adjust the photoluminescence performance.
Nitrogen dioxide (NO2) is a gas species that plays an important role in certain industrial, farming, and healthcare sectors. However, there are still significant challenges for NO2 sensing at low ...detection limits, especially in the presence of other interfering gases. The NO2 selectivity of current gas-sensing technologies is significantly traded-off with their sensitivity and reversibility as well as fabrication and operating costs. In this work, we present an important progress for selective and reversible NO2 sensing by demonstrating an economical sensing platform based on the charge transfer between physisorbed NO2 gas molecules and two-dimensional (2D) tin disulfide (SnS2) flakes at low operating temperatures. The device shows high sensitivity and superior selectivity to NO2 at operating temperatures of less than 160 °C, which are well below those of chemisorptive and ion conductive NO2 sensors with much poorer selectivity. At the same time, excellent reversibility of the sensor is demonstrated, which has rarely been observed in other 2D material counterparts. Such impressive features originate from the planar morphology of 2D SnS2 as well as unique physical affinity and favorable electronic band positions of this material that facilitate the NO2 physisorption and charge transfer at parts per billion levels. The 2D SnS2-based sensor provides a real solution for low-cost and selective NO2 gas sensing.
Quasi-two-dimensional (quasi-2D) molybdenum disulfide (MoS2) is a photoluminescence (PL) material with unique properties. The recent demonstration of its PL, controlled by the intercalation of ...positive ions, can lead to many opportunities for employing this quasi-2D material in ion-related biological applications. Here, we present two representative models of biological systems that incorporate the ion-controlled PL of quasi-2D MoS2 nanoflakes. The ion exchange behaviors of these two models are investigated to reveal enzymatic activities and cell viabilities. While the ion intercalation of MoS2 in enzymatic activities is enabled via an external applied voltage, the intercalation of ions in cell viability investigations occurs in the presence of the intrinsic cell membrane potential.
Although the development of Gobi Desert in central and eastern Asia has greatly affected the regional and even the global climate, its precise origin and evolution have yet to be determined. The ...three preconditions for the formation of Gobi Desert are: i) a dry climate, ii) basin landforms and iii) abundant sediment production. In this study, we present a synthesis of both new and published data on the formation and evolution of Gobi Desert in central and eastern Asia. We conclude that the combined effects of mountain building, the mid-latitude westerly circulation and changes in the Asian monsoon, accompanied by global cooling, were principally responsible for the formation of modern Gobi Desert landscapes in central and eastern Asia during the late Pliocene. The arid climate in central and parts of eastern Asia probably developed in the early Cenozoic, from ~50 Ma. Related events included the collision of the Indian and Asian plates, the closure and complete retreat of the Paratethys Ocean from central Asia, and the growth of the Himalayas and the Tibetan Plateau in the Eocene through late Miocene, which blocked the water vapor supply and intensified the aridification of the Asian interior. Superimposed on the topographic changes was the process of stepwise global cooling since the early Oligocene, and in particular since the late Miocene, which controlled the formation and evolution of the Gobi Desert landscape. Global cooling weakened the Asian monsoon circulation, strengthened the westerly circulation and enhanced physical weathering processes in mountain areas, which together promoted both the aridification of the Asian interior and sediment production. These processes finally resulted in the establishment of the modern Gobi Desert landscape in the late Pliocene. We estimate that the modern Gobi Desert landscape was formed at ~2.6 Ma and was the result of the stepwise evolution of Asian topography and climate during the Cenozoic, dominated by Asian tectonic deformation and uplift, and the evolution of Asian monsoon climate and the westerly circulation, forced by global temperature change.
Cancer is the second-most lethal global disease, as per health reports, and is responsible for around 70% of deaths in low- and middle-income countries. Endometrial cancer is one of the emerging ...malignancies and has been predicted as a public health challenge for the future. Insulin resistance, obesity, and diabetes mellitus are the key metabolic factors that promote risks for the development of endometrial cancer. Various signaling pathways and associated genes are involved in the genesis of endometrial cancer, and any mutation or deletion in such related factors leads to the induction of endometrial cancer. The conventional way of drug delivery has been used for ages but is associated with poor management of cancer due to non-targeting of the endometrial cancer cells, low efficacy of the therapy, and toxicity issues as well. In this context, nanocarrier-based therapy for the management of endometrial cancer is an effective alternate choice that overcomes the problems associated with conventional therapy. In this review article, we highlighted the nanocarrier-based targeting of endometrial cancer, with a special focus on targeting various metabolic signaling pathways. Furthermore, the future perspectives of nanocarrier-based targeting of metabolic pathways in endometrial cancer were also underpinned. It is concluded that targeting metabolic signaling pathways in endometrial cancer via nanocarrier scaffolds is the future of pharmaceutical design for the significant management and treatment of endometrial cancer.
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•Endometrial cancer rates fourth, mortality sixth in women.•Endometrial cancer risk increases with insulin resistance, obesity, and diabetes.•Nanocarrier-based cancer therapy effectively addresses conventional challenges.•Review explored nanocarrier-based targeting of endometrial cancer metabolic pathways.•Nanocarriers targeting metabolic signalling pathways are the future of medicine.
Nickelous oxide (NiO) is a promising anode for Lithium ion (Li-ion) batteries. However it suffers from rapid degradation due to large volume change upon cycling. In this work, a novel strategy to ...accommodate the volume change of NiO-based anodes during charge/discharge cycling through employment of the advantages of bimodal porous Nickel–Silicon (Ni–Si) network and Nickelous oxide@Nickel (NiO@Ni) shell@core structure is proposed. The designed bimodal nanoporous NiO@Ni–Si network exhibits a stable Li-ion storage property with an extremely high reversible capacity of 1656.9 mAh g−1 at 200 mA g−1 after 300 repeated cycles and 1387.1 mAh g−1 at 500 mA g−1 after 1000 cycles. It also shows a good rate performance, delivering about 400 mAh g−1 even at a current density of 2000 mA g−1. Post-cycling microscopy and impedance studies reveals the minor changes in the electrode structure that, in turn, results in an extremely low capacity degradation rate of 0.03%/cycle. The employed strategy enriches the structural design idea of dealloying products, which may further promote the development of the dealloying field and can be applied in future to prepare various types of porous shell@core anodes for Li-ion battery applications.
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•Bimodal nanoporous NiO@Ni–Si network is prepared by dealloying method.•The material contains bimodal porous Ni–Si network and NiO@Ni shell@core structure.•Huge volume change is accommodated by bimodal porous shell@core network.•The composite shows stable storage performance as an anode for Li-ion battery.
Pancreatic cancer (PC) is the most lethal malignancy worldwide due to its delayed diagnosis and limited treatment options. Despite great progress in clinical trials of immunotherapies for various ...cancers, their effectiveness in PC is very low, indicating that immune evasion is still a major obstacle to immunotherapy in PC. However, the mechanism of immune escape in PC is not fully understood, which substantially restricts the development of immunotherapy. As an important component of intercellular communication networks, extracellular vesicles (EVs) have attracted increasing attention in relation to immune escape. This review aims to provide a better understanding of the roles of EVs in tumor immune escape and the potential to expand their application in cancer immunotherapy. The relationship between PC and the tumor immune microenvironment is briefly introduced. Then, the mechanism by which EVs are involved in immune regulation is summarized, and the latest progress in determining the role of EVs in regulating PC immune escape is highlighted.
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