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Objective Peripheral artery disease (PAD) is often caused by atherosclerosis. However, causes other than atherosclerosis is often overlooked. Popliteal artery entrapment syndrome (PAES) and popliteal artery adventitial cystic disease (PACD) are two common nonatheromatous causes of claudication and critical limb ischemia. The purpose of this study is to present early results of treatment of PAES and PACD involving the lower limbs. Methods From December 2019 to February 2021, 10 patients with PAES underwent surgeries, and 1 patient with PAES received conservative treatment. 2 patients with PACD underwent surgery. Patient data including age, gender, etiology of vascular pathology, diseased vessel, surgical method, and hemodynamic status were collected retrospectively. Results The mean follow-up duration was 5.64 ± 3.72 months (range, 1–12 months). All patients had their symptoms improved or resolved. The success rate of surgery was 100%, the rate of freedom from reintervention for any reason was 100%. There were no death, bleeding, embolism, or skin ulcers during late follow-up. Conclusions PAES and PACD require early diagnosis and intervention, and early surgery may lead to good early- and mid-term results.

Graphical abstract, A key to tackling the coronavirus disease 2019 (COVID-19) pandemic is to understand how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) manages to outsmart host antiviral defense mechanisms. Stress granules (SGs), which are assembled during viral infection and function to sequester host and viral mRNAs and proteins, are part of the antiviral responses. Here, we show that the SARS-CoV-2 nucleocapsid (N) protein, an RNA binding protein essential for viral production, interacted with Ras-GTPase-Activating protein SH3-domain-binding protein (G3BP) and disrupted SG assembly, both of which require intrinsically disordered region1 (IDR1) in N protein. The N protein partitioned into SGs through liquid-liquid phase separation with G3BP, and blocked the interaction of G3BP1 with other SG-related proteins. Moreover, the N protein domains important for phase separation with G3BP and SG disassembly were required for SARS-CoV-2 viral production. We propose that N protein-mediated SG disassembly is crucial for SARS-CoV-2 production.

The multi-walled carbon nanotubes (MWCNTs)-anatase composites were prepared by ball-milling method. The influence of milling conditions (dry-milling or wet-milling) on the phases, morphology, dispersion, and electromagnetic wave absorption properties of the samples was studied. After characterization, the results indicated that ball-milling process had little effect on the phase and the grain size of anatase. The dispersion of MWCNTs in MWCNTs-anatase composites for wet-milling was preferable to that for dry-milling. The composites prepared by dry-milling method had an excellent electromagnetic wave absorbing property. The minimum value of RL was −37.3 dB at 6.1 GHz with the thickness of 3 mm, and the effective bandwidth was 6.1 GHz for the thickness in the range of 2–5 mm. Debye relaxation process, eddy current loss, and impedance matching were the main reasons for the electromagnetic wave absorption of the composites. The MWCNTs-anatase composites could be an easy obtained wave absorption materials.

Hyperglycemia remission by metabolic surgery is implicated in the resolution of low-grade inflammation in type 2 diabetes mellitus (T2DM). However, whether this beneficial effect of metabolic surgery is related to improving monocyte inflammatory response remains undefined. This investigation is addressed to evaluate this relationship. For this purpose, T2DM rats were subjected to Roux-en-Y gastric bypass (RYGB) and/or monocyte depletion or splenic sympathetic denervation. Fasting blood glucose (FBG), plasma tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) were measured, and monocyte inflammatory response was assessed in vitro. The data showed that RYGB significantly reduced lipopolysaccharide (LPS)-induced release of TNF-α and IL-1β from peripheral monocytes while alleviating hyperglycemia and reducing plasma TNF-α and IL-1β levels. Hyperglycemia resulting from monocyte depletion by injection of clodronate liposomes resolved one week earlier than vehicle control after RYGB. Splenic denervation abrogated the glucose-lowering effect and decreased LPS-stimulated TNF-α and IL-1β release from monocytes following RYGB. Overall, our results reveal that a marked reduction of monocyte inflammatory response after RYGB contributes to hyperglycemia remission in T2DM rats. The beneficial effect of RYGB is mediated through vagal-spleen axis anti-inflammatory activity.

A novel hybrid structured TiO2/Epoxy resin has been prepared by a simple in-situ synthetic method, which was used to enhance alkali-activated slag/fly ash (AASF) geopolymer paste for the first time. The study examined the durability performance of the paste by exposing specimens to two aggressive conditions, including wetting-drying cycles and continuous immersions in phosphoric acid solutions for 90 days. Visual appearances, physical, mechanical properties and microstructures of samples were analysed. Besides, degradation kinetics were monitored by measuring degradation depths. The results indicate that TiO2/Epoxy resin composite is able to improve the microstructures and limit the propagation of cracks. It is assumed that the hydroxyl groups of the epoxy resin and the bonded water in the aluminosilicate gel may form hydrogen bonds which make the binder matrix dense and homogeneous. The matrix thus intrinsically has a better fracture behavior with the existence of organic-based TiO2/Epoxy resin compared to the inorganic-based aluminosilicate crosslinked networks. The study also revealed that compared to the AASF without the composite addition, TiO2/Epoxy resin composited AASF exhibited a lower degradation kinetic regardless of exposure conditions. Therefore, a new direction is developed and recommended to use TiO2/Epoxy resin to improve the durability of AASF geopolymer regarding aggressive exposure environments. In addition, the manufacturing of TiO2/Epoxy resin composited AASF binder is relatively simple, cost-effective and eco-friendly with low carbon footprint.

In cold coastal area, the destruction mechanism of reinforced concrete structures is mainly governed by a combination of factors such as self-loading, freeze–thaw and chloride erosion. In this study, ordinary cube concretes (C30 and C50, while w/c = 0.53 and 0.35 respectively) underwent a coupling effect of pressure load with stress ratio of 0, 0.3 and 0.5 and freeze–thaw cycles, following by capillary water absorption test and chloride penetration test. Concrete samples with 0.3fc showed the best water and chloride penetration resistance under the coupling effect, followed by samples with 0.5fc and 0fc, which is consistent with the conclusion that under load only. Water and chloride ions penetration increased sharply when freeze–thaw cycles was over 100 times, which is different with samples without load. Outside part of concrete showed higher permeability and chloride content than inside part. MIP results confirmed that stress played an important role in the water absorption and chloride penetration of concrete under the coupling effect. These results provide important new insights into the permeability of concrete under a coupling effect. The applied load performed a more important role on the service life prediction of concrete structure.

In the present paper, graphene oxide (GO) was used to modify isobutyltriethoxysilane. GO/isobutyltriethoxysilane composite emulsion was then prepared by the sol–gel method. The properties of the obtained composite emulsion were characterized by Fourier Transform Infrared (FT-IR), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS). The waterproof performance of GO/isobutyltriethoxysilane composite emulsion was studied by capillary water absorption and water contact angle experiments. The FT-IR results showed that the number of Si–O bonds in the composite emulsion were superior to that in silane emulsion while carboxyl groups were found to be less. This indicated that GO was successfully grafted to the isobutyltriethoxysilane monomer. The XPS data showed that amounts of C–OH in the composite emulsion were lower than those in silane emulsion, suggesting that part of C–OH in the composite emulsion participated in formation of Si–O–C covalent bond between GO and silane. SEM and EDS revealed that the composite emulsion and silane emulsion could form a dense hydrophobic layer on the concrete surface, thereby achieving waterproof effect. Water contact angle and capillary water absorption tests of concrete indicated composite emulsion with significantly improved waterproof performances when compared to silane emulsion.

Human T-cell leukemia virus 1 (HTLV-1), an oncogenic retrovirus, and Notch1 signaling, implicated in tumor formation and progression, are both associated with the development of adult T-cell leukemia (ATL). Here we explored the possibility of a mechanistic link between the two. We observed that the expression of Notch intracellular domain (NICD) was elevated in HTLV-1 infected cell lines. Knocking down of Notch1 in ATL cells repressed cellular proliferation and tumor formation both in vitro and in vivo. As a mechanism for these actions, we found that Tax activated Notch1 signaling by prolonging the half-life of NICD. We then showed that Tax, NICD, and RBP-jκ formed a ternary complex, that Tax enhanced the association of NICD with RBP-jκ, and that Tax, NICD, and RBP-jκ were bound to RBP-jκ-responsive elements. Hence, our results suggest that HTLV-1 promotes cellular proliferation and tumor formation of ATL cells by modulating Notch signaling via a posttranslational mechanism that involves interactions between Tax, NICD, and RBP-jκ.

The movement of water and ions in the calcium silicate hydrate (C-S-H) gel pores determines the durability for the material. In this study, molecular dynamics was utilized to study aqueous NaCl solution capillary transport through the C-S-H gel pore with pore size of 3.5 nm, 2.5 nm, 1.5 nm and 1 nm. The penetration depth for the solution advancing frontier with menisci shape follows a parabolic relation as the function of time, matching well with classic LW capillary adsorption theory. The progressively reduction for the solution/C-S-H contact angle reflects the hydrophilic nature of the C-S-H surface. With decreasing of C-S-H gel pore size, the ions are filtered by the small C-S-H gel pore, with water invading deeply in the gel pore, and chloride and sodium ions remaining in the region of gel pore channel entry. The ultra-slow transport mechanism for ions in the nanometer channel has been further explained by the local structure and dynamics of ions hydrated ultra-confined in the gel pore. While the silicate chains in C-S-H surface can provide non-bridging oxygen sites to associate with the sodium ions by Na-Os connection, the courter calcium ions in C-S-H surface can capture the chloride ions, forming the ionic pair. Both Na-Os and Ca-Cl pairs have longer resident time that the unstable H-bond connection between water and solid oxygen. Furthermore, the transition region with slow mobility is formed at the channel entry region due to the coupling immobilization effect by both surfaces normal and parallel to the transport pathway. The presence of transition zones results in the necking of channel entry, which inhibits the ions with larger hydration shell from penetration. Additionally, at channel with size less than 2 nm, the Ca-Cl and Na-Cl ionic pairs accumulate to cluster and are highly concentrated in the center of the gel pore, blocking transport pathway for water molecules and ions.

Co@C/CNTs magnetic carbon nanomaterials were fabricated by a gaseous detonation method with cobalt (III) acetylacetonate (Co(acac)3) as precursor and a mixture gas of hydrogen and oxygen as explosion source. The current work investigates how proportion of oxygen in the mixture gas affects the morphologies, phases, and degree of graphitization of Co@C/CNTs nanomaterials. The characterization of transmission electron microscopy indicates that the samples were consisted of core-shell nanoparticles and nanotubes, and the proportion of oxygen had little influence on the morphologies of the samples. X-ray diffraction and Raman spectra analysis demonstrate that the core-shell particles and nanotubes were Co@C and CNTs, respectively. The cobalt nanoparticles generated from the decomposition of Co(acac)3 would be oxidized to CoO when the proportion of oxygen was greater than 50% in the mixture gas. Though the degree of graphitization of Co@C/CNTs nanomaterials was little affected by the proportion of oxygen, the particle size of Co@C increased with the increase of the proportion of oxygen in the mixture gas, simultaneously, the carbon matrix was decreased.

Corrosion monitoring of reinforced bar is critical for evaluating the safety and durability of concrete structures. The aim of this paper is to introduce a novel electro-magnetic monitoring apparatus (EMMA) that can be used to monitor corrosion of reinforced bar in concrete. 24 Hall-effect sensors are mounted on the novel EMMA with linearly arrangement and an enlargement monitoring probe is also equipped, by which the magnetic field intensity variation of reinforced bar/concrete interface can be detected. For comparison, the traditional electro-chemical impedance spectroscopy of the reinforced bar in concrete was recorded. As the results shown, the magnetic flux changed when corrosion occurred on reinforced bar, which further induced the increase of Hall-effect voltage at cross section of reinforced concrete. With the information of changed Hall-effect voltage, damage identification and orientation in concrete can be recorded by the EMMA. This can be used to monitor and analyze the reinforced bar corrosion in concrete time-dependently.

Pull-out test was conducted to investigate the bond behaviour between recycled aggregate concrete and steel bar after rapid freezing-thawing cycles in fresh water and saline water. The test variables were number of freezing-thawing cycles (0, 25, 50 and 75), diameter of steel bar (14, 18 mm) and freezing-thawing medium (fresh water, saline water). According to the test results, the effect of freezing-thawing cycles, diameter of steel bar and freezing-thawing medium on the bond behaviour was analysed. It was found that the bond strength between steel bar and recycled aggregate concrete decreases as the freezing-thawing cycles increased, and after the same number of rapid freezing-thawing cycles, the loss of bond strength in saline water was greater than that in fresh water. Moreover, the loss of compressive strength was greater than the loss of bond strength between steel bar and recycled aggregate concrete after the same number of rapid freezing-thawing cycles in saline water.

The use of local aluminosilicates to serve the local engineering applications could resolve the issue of unpredicted properties of the geopolymer caused by the wide variance in aluminosilicates reactivity. The locally available aluminosilicate byproducts (e.g., fly ash [FA] and granulated ground blast-furnace slag [GGBS]) in Qingdao were used to synthesize geopolymer cement in this study. Six geopolymer cement mortars with different FA/GGBS ratios were compared with ordinary Portland cement (OPC) and magnesium potassium phosphate cement (MKPC) mortars in terms of workability, setting time, strength development, volume stability and chloride permeability. The use of high volume of GGBS equips the geopolymer mortars with fast setting and high early strength despite poor volume stability. Thus, GGBS geopolymer mortars could potentially replace the high-cost MKPC mortar for rapid rehabilitation in construction. The geopolymer cement mortar with a FA/GGBS ratio of 4 behaves similar to OPC mortars in terms of fluidity, setting time, strength development, volume stability and chloride permeability. Therefore, FA-based geopolymer mortar blended with 20% GGBS could be considered as a high-efficiency, low-cost, eco-friendly and sustainable replacement of OPC mortar. Overall, the geopolymer cement properties could be engineered based on the FA/GGBS ratio in order to serve local engineering applications for the maximum utilization in different scenarios.

Structure-controlled nickel @nitrogen-doped porous carbon/carbon nanotube (Ni@NC/CNT) nanocomposites derived from metal−organic frameworks (MOFs) were successfully synthesized via sintering Zn-Ni precursor under the nitrogen atmosphere. Appropriately regulating the molar ratio of Zn-Ni could effectively control the content and length of CNTs and realize unique structures, as demonstrated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy characterization. According to the vector network analyzer test, Ni@NC/CNT nanocomposites displayed outstanding electromagnetic wave absorption performance, which can be attributed to magnetic-dielectric synergy effect, impedance matching, multifarious transmission paths, interface polarization and dipole polarization between Ni nanoparticles (NPs), N-doped porous carbon shell and CNTs. Surprisingly, when the molar ratio of Zn-Ni was 1:3, the maximum reflection loss (RL) of the optimized nickel @nitrogen-doped porous carbon/carbon nanotube-1/3 (Ni@NC/CNT-1/3) nanocomposite reached up to -74.06 dB at 15.63 GHz with a matching thickness of only 1.911 mm. Furthermore, the largest effective absorption band width (

It would make sense to detect the rules and mechanisms of degradation and mass transport of alkali-activated slag concrete (AASC) in actual service environment. In this paper, hydration products characterization implies higher crystallinity degree of C-S-H activated by NaOH and higher polymerization of the one activated by water glass. During compressive loading, Poisson's ratio of AASC keeps constant at the stress level ranging from 0 to 0.5, with an uprush takes place at stress level of 0.8–0.9. For slag concrete activated by NaOH, volume increases with stress level, while the volume of slag concrete activated by water glass decreases first and then increase with stress level. The apparent chloride diffusion coefficient of specimens activated by NaOH is 4–7 times smaller than the ones activated by water glass, which is verified by the results that volume of pores above 10 μm of water glass activated sample is nearly 20 times more than that of NaOH activated one. Slag concrete activated by water glass is compacted considerably by compressive loading contributing to the decrease in chloride diffusivity, while no significant compacting phenomenon is observed in slag concrete activated by NaOH. However, there is no significant compacting effect on capillary absorption for both specimens activated by two activators.

Photoplethysmography has been routinely used for health monitoring in the past decades. Even though in daily medical practice, photoplethysmograms (PPGs) are recorded at red and near infra-red light (rPPGs), during the last decade, PPGs obtained at green light (gPPGs) have been widely used in wearable devices, such as wristbands and smartwatches, thus providing highly usable and accessible daily health monitoring. It is well recognized that PPG signals obtained at NIR light contain sufficient information about a person's health; furthermore, they are well-studied and highly complex. By contrast, green light PPGs have not been sufficiently studied; thus, it is not clear whether the provided information is as valuable as that obtained by rPPGs, as green light photoplethysmography is formed at papillary dermis and higher skin levels. However, the gPPG signal is recognized to be more robust to motion artifacts compared with rPPGs. As rPPG dynamics has been recognized as chaotic, this study is aimed at investigating the properties of gPPGs and compare them with those of rPPGs to determine whether gPPG dynamics is chaotic as well. The motivation for this question was not only to investigate whether gPPGs can be used for the same range of applications as rPPGs but also to obtain insight into whether the complexity of rPPGs is solely due to processes in deeper layers of the tissue or it is influenced by the higher-skin layers processes that create gPPGs. The obtained results demonstrated that gPPGs, as well as rPPGs, are chaotic, which implies that processes in the upper layers create chaos in PPG data, whereas the contribution of arterial blood volume changes is not completely clear.

A hydrogen–oxygen gas detonation was direct initiated by using a 20 J electronic spark, and the pressure and temperature of which were measured by a pressure sensor and high-speed camera, respectively. The results showed the mixed gas was direct initiated in the propagation of detonation wave. The carbon nanomaterials were prepared by decomposition of ferrocene and cobalt (III) acetylacetonate (Co(acac)3), a the samples were characterized by X-ray diffractometer, transmission electron microscope, engergy dispersive X-ray detector and Raman spectrometer. The results indicated that carbon-encapsulated metal nanoparticles were fabricated by using ferrocene, ferrocene–Co(acac)3 as a precursor, and the core–shell nanostructures were carbon-encapsulated Fe/Fe3C nanoparticles (Fe@C) and carbon-encapsulated Co nanoparticles (Co@C). However, the Fe–Co alloy was absent in sample from ferrocene–Co(acac)3. It is interesting that the sample from Co(acac)3 were Co@C and multi-walled carbon nanotubes (MWCNTs), and the crystallization degrees of the carbon and Co nanoparticles in the MWCNTs were higher than that of in carbon-encapsulated metal nanoparticles, however, the degree of graphitization of the powders was low. The physical properties of precursors, hydrogen content and rapid reaction were the main factors which contributed to the different morphologies and the absence of Fe–Co alloy.

Graphene quantum dots (GQDs) in high reproducibility are synthesized by a gaseous detonation method which converts untreated benzoic acid (BA) precursor into powdered GODs without complicated post-treatment in 3–5 ms. The as-prepared GQDs resulting in an absolute photoluminescence quantum yield (PLQY) of 21.5% exhibit dual-wavelength-independent emission with the maximum PL emission at 431 nm and 460 nm under excitation maximum at 300 nm dispersed in ethyl alcohol. Based on surface structure, photoluminescence (PL) behaviors of GQDs and the characteristics of gaseous detonation, the formation mechanism of GQDs is speculated. Moreover, further study regarding the optical properties of reducing GQDs (R-GQDs) and thermal annealing GQDs (A-GQDs), it is possible to reveal PL mechanism of GQDs. This research not only provides a one-pot solvent-free route to rapid and large-scale preparation of GQDs, but also accounts for the hypothetic formation and PL mechanism of the obtained GQDs.

Service life and durability of reinforced concrete structures have become crucial issues in all industrialized countries because of their economic and ecological relevance. Limited durability is frequently due to deterioration of steel and cement-based materials, such as mortar and concrete, by interactions with water and aggressive aqueous solutions. Neutron imaging has proved to be a powerful non-destructive technique to study quantitatively water content and water movement in porous materials. A neutron beam is much more attenuated by hydrogen in water than by most other elements present in cement-based materials. In this review, focus is placed on applications of both two-dimensional neutron radiography and three-dimensional neutron tomography to investigate specific aspects of durability and deterioration of cement-based materials. Examples of results obtained by qualitative and quantitative investigations of moisture movement in cracked and uncracked cement-based materials are presented. Self-healing, efficiency of water repellent treatment, internal curing, frost damage, fire spalling, ettringite formation and observations of various reinforced concrete components are addressed. The results obtained by neutron imaging provide a solid basis for better understanding of deterioration mechanisms of cement-based materials. Recent improvements of neutron imaging facilities have allowed unexpected possibilities to study complex processes in cement-based materials. The potential for further research based on this promising technology is outlined and discussed.

Multiwalled carbon nanotubes (MWCNTs) were fabricated via the detonation of a mixed gas consisting of ferrocene vapor, methane, and oxygen. The samples were characterized using transmission electron microscopy, X-ray diffraction, Raman spectroscopy, vibrating sample magnetometry, and a vector network analyzer. The results indicate that the samples were MWCNTs that were about 30 nm in external diameter, about 15 nm in inner diameter. The ferrocene dosage had an obvious effect on the morphology, degree of graphitization, and magnetic property of the MWCNTs. The growth mechanism of the MWCNTs in the gaseous detonation process was discussed using the detonation Zeldovich-von Neumann-Doring model and a vapor-liquid-solid growth model. The minimum reflection loss of the MWCNTs was −6.1 dB at 11.2 GHz with a thickness of 2 mm, which is lower than that of the MWCNTs prepared via other methods, and the reasons for this result are analyzed in the paper.

The hydration and dissolution of tri-calcium silicate mineral is of great importance for guiding the material design. In order to understand the hydration mechanism of C3S mineral in sodium sulfate solution, molecular dynamics was employed to construct three interface models of C3S and Na2SO4 solution of 0 mol/L, 0.79 mol/L and 1.58 mol/L and the structure, dynamics and dissolution properties of the interfacial species were investigated. Due to hydrophilic nature of C3S surface, the water molecule in hydrate layer deeply tessellated on the vacancy surface region shows high intensity packing, ordered arrangement, enlargement of the dipolar moment value and orientation preference. With progressively increasing simulation time, the hydroxyl groups and calcium atoms in the high reactive surface gradually escape from the substrate bonding restriction and diffuse away to the solution region. Furthermore, both ions prefer to adsorbing on the surface of tri-calcium silicate mineral: the highly solvated surface calcium ions associate with the oxygen sites in the sulfate ions, forming the Ca SO4 ionic pairs in the interfacial region; the sodium ions are attracted by the non-bridging oxygen in the silicate monomers, forming Na O connection. The surface adsorbed water molecules, sulfate and sodium ions, strongly associated with the calcium atoms and hydroxyl groups, form a ionic and hydrate layer, stabilizing the tri-calcium silicate surface and inhibiting the dissolution of ions in C3S. With increasing ions’ concentration, the sulfate and sodium ions in the solution are more probable to form cation-anion pairs and further accumulate to the ionic cluster.

Strain Hardening Cementitious Composites (SHCC) exhibit multiple crack characteristics when subjected to a bending or tensile load. In this paper, SHCC specimens were preloaded under three-point bending to introduce multiple microcracks and exposed to different conditions to assess their self-healing. Observation and analysis of crack characteristics, water absorption tests by a gravimetric method and neutron radiography were conducted to study the self-healing behaviour of microcracks in SHCC under three conditions (water fog, water/dry cycle, Ca(OH)2 solution/dry cycle). The results indicate that self-healing is a slow process, even in the presence of liquid water or calcium hydroxide solution. The crack sealing degree decreases with the increase in crack width, and only fine cracks of 10–20 μm can be healed completely. Ca(OH)2 solution promotes the healing process due to the enhancement of the pozzolanic reaction of fly ash. Water capillary absorption can be significantly reduced by crack sealing. The correlation between the crack sealing degree (crack closure) and water absorption reduction can be described well by a linear function.

Corrosion of steel reinforcement is one of the major durability problems for reinforced concrete structures. The steel corrosion in both ordinary mortar and strain hardening cementitious composites (SHCC) has been for the first time visualized by means of neutron tomography in three dimensions with high resolution. It has been found that the steel rebar starts corroding from the bottom interface between the steel and cementitious matrix. The corrosion products mainly exist around the cracks. Microcracking SHCC has higher resistance against steel rebar corrosion than cracked ordinary mortar.

A four-channel Tic-Tac-Toe (TTT) transmit RF coil was designed and constructed for foot and ankle imaging at 7T MRI. Numerical simulations using an in-house developed FDTD package and experimental analyses using a homogenous phantom show an excellent agreement in terms of B1 + field distribution and s-parameters. Simulations performed on an anatomically detailed human lower leg model demonstrated an B1+ field distribution with a coefficient of variation (CV) of 23.9%/15.6%/28.8% and average B1 + of 0.33 μT/0.56 μT/0.43 μT for 1 W input power (i.e., 0.25 W per channel) in the ankle/calcaneus/mid foot respectively. In-vivo B1 + mapping shows an average B1 + of 0.29 μT over the entire foot/ankle. This newly developed RF coil also presents acceptable levels of average SAR (0.07 W/kg for 10 g per 1 W of input power) and peak SAR (0.34 W/kg for 10 g per 1 W of input power) over the whole lower leg. Preliminary in-vivo images in the foot/ankle were acquired using the T2-DESS MRI sequence without the use of a dedicated receive-only array.

With the boosting development of wireless communication, highly efficient electromagnetic wave absorption (EMA) materials are urgently need in military and civilian fields. However, how to combine magnetic loss and dielectric loss materials effectively to achieve highly efficient EMA efficiency remains a challenge. Herein, dual-loss Ti3C2Tx MXene/Ni0.6Zn0.4Fe2O4 (MXene/NZFO) heterogeneous nanocomposites were successfully synthesized by incorporation of magnetic NZFO nanoparticles onto the surface and between the layers of MXene via a straightforward in-situ hydrothermal method. The MXene/NZFO heterogeneous nanocomposites hold outstanding electromagnetic wave attenuation ability, which can be attribute to the impedance matching, magnetic-dielectric synergy effect, more interfaces polarization and increased transmission paths. In particular, the optimized MXene/NZFO-2 heterogeneous nanocomposites exhibit an excellent microwave absorption performance that the maximum reflection loss (RL) reaches up to −66.2 dB at 15.2 GHz and an effective absorbing bandwidth of 4.74 GHz with the thickness of only 1.609 mm. Therefore, this work provides a new insight to design and construct excellent EMA candidates with multiple loss, which be favorable to solve electromagnetic pollution problems.

With the rapid development of wireless technology, electromagnetic interference and pollution have been a serious harmful problem to human health. Therefore, it is greatly significant to design and explore efficient electromagnetic wave (EMW) absorbing coatings on the surface of devices, mortar or other building materials. In this paper, a series of novel Ni0.6Zn0.4Fe2O4/Ti3C2Tx nanocomposite modified epoxy resins with different additive content were successfully prepared to serve as absorbing and anticorrosive coating on cement mortar. The effect of the content of Ni0.6Zn0.4Fe2O4/Ti3C2Tx nanocomposite in epoxy resin as coatings of cement mortar on mechanical properties, interfacial bonding ability, corrosion performances and reflectivity performances was detailly investigated. Apparently, when 3% Ni0.6Zn0.4Fe2O4/Ti3C2Tx nanocomposite is added into epoxy resin, the cement mortar with modified coatings exhibits the most excellent EMW absorption properties, whose the minimum reflectivity is −34.39 dB, the absorption bandwidth with reflectivity lower than − 10 dB is about 8.96 GHz. Besides, both capillary sorptivity and chloride penetration tests demonstrated that the impermeability of water and chloride ions of cement mortar coated by modified epoxy coatings was obviously improved with the increase of Ni0.6Zn0.4Fe2O4/Ti3C2Tx nanocomposite compared to cement mortar without coatings and with pure epoxy resin coating. In particular, the optimized modified epoxy resin with 3% dosage of Ni0.6Zn0.4Fe2O4/Ti3C2Tx nanocomposite also displays the lowest capillary sorptivity and chloride permeability. Our findings proved that the use of Ni0.6Zn0.4Fe2O4/Ti3C2Tx nanocomposite modified epoxy resin as coatings of cement mortar provides a viable source for solving electromagnetic pollution and impermeability problems in military and civilian applications.

A highly-dispersed reduced graphene oxide/epoxy resin (RGOEP) composite was synthesized and used to improve related properties of alkali-activated slag (AAS) binders. This study scrutinizes the effects of epoxy resin and RGOEP composite on the hydration products, microstructure and mechanical properties (especially fracture toughness) of the AAS binders activated by water glass or NaOH solutions. The experimental results showed that RGOEP (3 wt%) is able to significantly improve the fracture toughness of the AAS mortars activated by water glass and NaOH, with more than 42.3 and 13.3 times greater, respectively, compared to the pure AAS counterpart. A peony flower-like hydration product was detected when RGOEP was used which is believed to result from the modification of AAS binding matrix by RGOEP at a nanoscale level. Besides, bonding tensile strength was also improved remarkably when 7 wt% GROEP was added into the BFS binders activated by water glass, almost up to 4.8 and 2.9 times as that of the control mortar and the one enhanced by 5 wt% EP, respectively. Thus, a unique advantage of reduced graphene oxide over epoxy resin in enhancing AAS binders was discovered. Considering a very low content of reduced graphene in epoxy resin (only 0.3 wt%), this research indicates great potential for wider industrial applications of this type of RGOEP in the AAS binders.

The applied load has significantly impacted on the permeability behavior of concrete. Although many investigations have reported the impact of loading level on the permeability, the influence of loading direction on the permeability received little consideration in previous publications. Therefore, this work gives a comprehensive study on the influence of loading level and its direction on water and chloride permeability. Applied loading experiment, water absorption experiment and chloride diffusion test were conducted in this work. The findings showed that the applied load increased the specific crack area and pore size distribution, and that the permeability increased as the applied loading level and duration increased. The water and chloride penetration whose direction is vertical to the applied loading direction is greater than that whose direction parallels the loading direction; in addition, the applied load direction shows larger effects on water ingress than on chloride ingress. Capillary absorption coefficient and chloride diffusion coefficient grow linearly as total porosity increases, and the chloride diffusion coefficient is in direct proportion to the capillary absorption coefficient. When the loading direction is vertical to water penetration, the capillary absorption coefficient of concrete after 75 % fc and 85 %fc increases by 25.76 and 28.27 (g/m2h1/2), compared with the case that the loading direction is parallel with water penetration. This paper further gives a relationship between concrete permeability and the induced loading damage.