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In this study, we reported a patient who presents with multicentric reticulohistiocytosis (MRH)-like clinical feature, but the histology is not compatible with it. Like our patient, a couple of patients described previously also had the dilemma that they could not be classified appropriately into any current histiocytosis entity. Considering the clinical and pathological features together, all these patients had a similar clinical profile: xanthomatous rash, erosive arthritis and histopathological findings showing xanthomized histiocytes. Therefore, we propose a new disease entity - xanthomatous erosive arthritis (XEA), to accommodate these patients that cannot be classified appropriately into the current system. more...

The Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2C-M x C composite ceramic was prepared by hot pressed sintering with the Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2C high entropy carbide as the main phase. Secondary phase M x C (M=Ti, Zr, Hf, Nb, Ta) was found to be distributed relatively uniform in composite ceramic. The oxidation behaviour of the ceramic was examined after exposure to 923 K and 1173 K. The morphology of the surface and cross-sections of all oxidation samples were observed. The characteristics of the oxidation behavior about high entropy carbide and secondary phase M x C were compared and analyzed. The secondary phases (such as Ti-rich carbide or Hf-rich carbide) in the material were seriously oxidized at 923 K and 1173 K, which reflects the superior oxidation performance of high entropy carbide. The nano high entropy oxides with Ti, Zr, Hf, Nb, Ta, O elements were discovered by oxidation of the composite ceramic. The above research is helpful to deepen the understanding of the oxidation mechanism of high entropy carbide and the composite ceramic. more...

The commutation failure of high voltage direct current (HVDC) systems could lead to unstable operation of the alternating current/direct current (AC/DC) hybrid power grid. The commutation voltage distortion caused by harmonics is a considerable but unclear factor of commutation failure. According to the control switching process of HVDC systems, the commutation voltage-time area method is employed to analyze and reveal the influence mechanism of harmonic components of commutation voltage on first and subsequent commutation failures. Considering the distortion characteristics of AC voltage, a predictive commutation failure suppression strategy considering multiple harmonics of commutation voltage is proposed. In this strategy, the new extinction angle and the zero-crossing offset angle after voltage distortion are calculated considering the harmonic components so as to obtain the compensation margin of the lag trigger angle by combining the correction margin with the voltage change rate. Moreover, the tuning method of parameters of extinction angle and voltage prediction variables are provided. Finally, a case study based on CIGRE standard HVDC system is performed and analyzed by using power systems computer-aided design (PSCAD) software. Compared with the International Council on Large Electric systems (CIGRE) standard test model and traditional commutation failure prevention (CFPREV) control model, the results verify that the proposed strategy can effectively reduce the risk of first and subsequent commutation failures and improve the sensitivity of CFPREV control. more...

Treatment of full-thickness skin defects still presents a significant challenge in clinical practice. Three-dimensional (3D) bioprinting technique offers a promising approach for fabricating skin substitutes. However, it is necessary to identify bioinks that have both sufficient mechanical properties and desirable biocompatibilities. In this study, we successfully fabricated acellular dermal matrix (ADM) and gelatin methacrylamide (GelMA) bioinks. The results demonstrated that ADM preserved the main extracellular matrix (ECM) components of the skin and GelMA had tunable mechanical properties. Both bioinks with shear-thinning properties were suitable for 3D bioprinting and GelMA bioink exhibited high printability. Additionally, the results revealed that 20% GelMA with sufficient mechanical properties was suitable to engineer epidermis, 1.5% ADM and 10% GelMA displayed relatively good cytocompatibilities. Here, we proposed a new 3D structure to simulate natural full-thickness skin, which included 20% GelMA with HaCaTs as an epidermal layer, 1.5% ADM with fibroblasts as the dermis, and 10% GelMA mesh with human umbilical vein endothelial cells (HUVECs) as the vascular network and framework. We demonstrated that this 3D bioprinting functional skin model (FSM) could not only promote cell viability and proliferation, but also support epidermis reconstruction in vitro. When transplanted in vivo, the FSM could maintain cell viability for at least 1 week. Furthermore, the FSM promoted wound healing and re-epithelization, stimulated dermal ECM secretion and angiogenesis, and improved wound healing quality. The FSM may provide viable functional skin substitutes for future clinical applications. Statement of significance We propose a new 3D structure to simulate natural full-thickness skin, which included 20% GelMA with HaCaTs as an epidermal layer, 1.5% ADM with fibroblasts as the dermis, and 10% GelMA mesh with HUVECs as the vascular network. It could not only maintain a moist microenvironment and barrier function, but also recreate the natural skin microenvironment to promote cell viability and proliferation. This may provide viable functional skin substitutes for future clinical applications. more...

HA/β-TCP biphasic calcium phosphate (BCP)ceramic materials have a wide application prospect in bone remodeling surgery as bone substitutes. This study extracted BCP from butterfish bone that was ca... more...

A ceramic core is the key component in the manufacture of the hollow turbine blades of aeroengines. Compared with the traditional injection molding method, 3D printing is more suitable for manufacturing ceramic cores with a complex geometry at high precision. However, the stair-stepping effect is inevitable in the 3D printing process and affects the surface roughness and strength of the ceramic core. In this study, to explore the influence of nano-silica content on the microstructure and properties of the ceramic core, silicon-based ceramic cores were fabricated with the addition of nano-silica powder by digital light processing and subsequent sintering at 1200 °C. The results showed that the apparent porosity and pore size of the ceramic core gradually decreased as both the nano-silica powder content and bulk density increased. Meanwhile, the printing interlayer spacing was significantly reduced, resulting in a low surface roughness, high flexural strength, and creep-resistance. To simulate the entire casting process of a superalloy blade, the thermal deformation behavior of the ceramic core was observed by heating and cooling cycles performed in a thermal dilatometer at 1540 °C. The total linear shrinkage decreased as the nano-silica powder content increased, which was mainly due to the phase transformation of cristobalite and the densification of the ceramic core sintered at 1200 °C. The low surface roughness and linear shrinkage as well as high flexural strength of the ceramic core can contribute to the excellent quality of cast superalloy blades. more...

With poor mechanical properties and engineering characteristics, loess soils alone cannot meet the requirements of high-speed railway subgrade and large-sized building foundations based on shear strength and bearing capacity. Therefore, it is necessary to improve the mechanical properties of loess. In soil reinforcement, encouraging outcomes have been achieved by using fibers as reinforcement material for its relatively low costs and the low environment impact results from this material. To investigate the mechanical properties and the reinforcement mechanism of fiber-reinforced loess, ring shear tests were performed on loess samples with varying polypropylene fiber contents (0%, 0.25%, 0.50%, 0.75%, and 1%) and moisture contents (12%, 14%, 16%, 18%, and 20%). Furthermore, the macroscopic structure and microscopic images of the shear plane of reinforced specimens were analyzed as well. The test results showed that firstly polypropylene fibers significantly improved the peak strength and the residual strength of loess, and the optimal fiber content and the optimal moisture content were found to be 0.5% and 16%, respectively. The theoretical relationships between the fiber content Fc, the moisture content Mc, the peak strength τ, and the residual strength τr of reinforced loess were quantitatively determined. In addition, the fiber reinforcement mechanism was revealed based on the macroscopic shear plane of fiber-reinforced loess and SEM microscopic images of the shear plane. more...

Cis-regulatory mutations underlie important crop domestication and improvement traits1,2. However, limited allelic diversity has hindered functional dissection of the large number of cis-regulatory elements and their potential interactions, thereby precluding a deeper understanding of how cis-regulatory variation impacts traits quantitatively. Here, we engineered over 60 promoter alleles in two tomato fruit size genes3,4 to characterize cis-regulatory sequences and study their functional relationships. We found that targeted mutations in conserved promoter sequences of SlCLV3, a repressor of stem cell proliferation5,6, have a weak impact on fruit locule number. Pairwise combinations of these mutations mildly enhance this phenotype, revealing additive and synergistic relationships between conserved regions and further suggesting even higher-order cis-regulatory interactions within the SlCLV3 promoter. In contrast, SlWUS, a positive regulator of stem cell proliferation repressed by SlCLV3 (refs. 5,6), is more tolerant to promoter perturbations. Our results show that complex interplay among cis-regulatory variants can shape quantitative variation, and suggest that empirical dissections of this hidden complexity can guide promoter engineering to predictably modify crop traits. more...

A model-free approach is proposed for anticipating the occurrence of measure synchronization in coupled Hamiltonian systems. Specifically, by the technique of parameter-aware reservoir computing in machine learning, we demonstrate that the machine trained by the time series of coupled Hamiltonian systems at a handful of coupling parameters is able to predict accurately not only the critical coupling for the occurrence of measure synchronization, but also the variation of the system order parameters around the transition point. The capability of the model-free technique in anticipating measure synchronization is exemplified in Hamiltonian systems of two coupled oscillators and also in a Hamiltonian system of three globally coupled oscillators where partial synchronization arises. The studies pave a way to the model-free, data-driven analysis of measure synchronization in large-size Hamiltonian systems. more...

Construction of high-speed railway subgrade on loess soils in the Loess Plateau is risky because such soil is susceptible to differential settlements. Various soil-improvement methods have been used to enhance the mechanical properties of loess. Lime-ash soil and cement-lime soil are the most commonly used methods in the improvement of loess subgrade, while few studies have been found on loess subgrade improvement by using composite material consisting of traditional materials and new materials. A series of direct shear tests and unconfined compressive tests were conducted on the loess specimen with the addition of three kinds of composite materials: traditional material cement, new material polypropylene fiber and SCA-2 soil curing agent. The numerical simulation was conducted on loess subgrade in an actual engineering practice. The experimental results show that cement, polypropylene fiber and SCA-2 soil curing agent can effectively improve the shear strength and compressive strength of loess, and the influence degree is cement > fiber > curing agent. Additionally, based on the relative strength characteristics of the improved loess, an optimal improvement scheme for the composite-material-modified loess was obtained: 16% cement content + 0.5% fiber content + 4% curing agent content. The numerical simulation results revealed that the compressive strength index of the improved loess has a significant impact on the subgrade settlement, and the optimal improvement scheme obtained from comprehensive analysis can effectively improve the settlement of high-speed railway subgrade under vibration load. more...

Here in, the effects of FeSiAl particle size on the dielectric and microwave absorption properties of FeSiAl/Al2O3 composites were studied. FeSiAl/Al2O3 composites containing 18–25 μm, 25–48 μm, and 48–75 μm FeSiAl particles were prepared by hot-pressed sintering based on uniformly mixed FeSiAl and Al2O3 powders. Results show that the real permittivity and the imaginary permittivity are significantly promoted with increasing FeSiAl particle size, which is ascribed to the enhanced interfacial polarization and conductance loss. In addition, the favorable matching impedance and suitable attenuation coefficient enabled the composite containing 25–48 μm FeSiAl powder to show a minimum reflection loss of −34.4 dB at 11.7 GHz and an effective absorption bandwidth ( more...