Confined In-Situ Encapsulation of Co/C Composites with Increased Heterogeneous Interface Polarization for Enhanced Electromagnetic Performance.

It is an urgent problem to realize reliable microwave absorption materials (MAMs) with low density. To address this issue, a series of controlled experiments w ere carried out, which indicated that the tubular structure enables excellent microwave absorption properties with a lower powder filling rate. This performance is attributable to the combined dielectric and magnetic loss mechanisms provided by Co/C and the interface polarization facilitated by multiple heterogeneous interfaces. Particularly, Co@C nanotubes, benefiting from the enhanced heterointerface polarization due to their abundant specific surface area and the reduced electron migration barrier induced by their 1D stacked structure, effectively achieved a dual enhancement of dielectric loss and polarization loss at lower powder filling ratios. Furthermore, the magnetic coupling effect of magnetic nanoparticle arrays in tubular structures is demonstrated by micromagnetic simulation, which have been few reported elsewhere. These propertied enable Co@C nanotubes to achieve minimum reflection loss and maximum effective absorption broadband values of 61.0 dB and 5.5 GHz, respectively, with a powder filling ratio of 20 wt% and a thickness of 1.94 mm. This study reveals the significance of designing 1D structures in reducing powder filling ratio and matching thickness, providing valuable insights for developing MAMs with different microstructures.

Dzyaloshinskii-Moriya-Interaction-Like Behavior in Confined Permalloy Nanostructures via Coupled Magnetic Vortices.

Dzyaloshinskii-Moriya interaction (DMI), one of antisymmetric exchanges, originates from the combination of low structural symmetry and large spin-orbit coupling and favors magnetization rotations with fixed chirality. Herein, this work reports a DMI-like behavior in permalloy via coupled vortices in confined structures. Under the in-plane magnetic fields, continuous reversals of different coupled vortices are directly observed by in situ Lorentz transmission electron microscopy, and reproduced by complementary micromagnetic simulations. The statistical results show that coupled vortices with opposite chirality appear more frequently with the frequency up to about 60%. Such an asymmetric phenomenon mainly arises from a DMI-like behavior, associated with the increased total energy difference between different ground-state coupled vortices. Moreover, in the reversal process, the junction between disks accelerates the annihilation of vortices moving toward it and is also the starting point of vortex nucleation. These results provide an effective method to generate a DMI-like behavior in magnetic systems with symmetry breaking surface and benefit the future development of vortex-based spintronic devices.

Quinary High-Entropy-Alloy@Graphite Nanocapsules with Tunable Interfacial Impedance Matching for Optimizing Microwave Absorption.

Designing heterogeneous interfaces and components at the nanoscale is proven effective for optimizing electromagnetic wave absorption and shielding properties, which can achieve desirable dielectric polarization and ferromagnetic resonances. However, it remains a challenge for the precise control of components and microstructures via an efficient synthesis approach. Here, the arc-discharged plasma method is proposed to synthesize core@shell structural high-entropy-alloy@graphite nanocapsules (HEA@C-NPs), in which the HEA nanoparticles are in situ encapsulated within a few layers of graphite through the decomposition of methane. In particular, the HEA cores can be designed via combinations of various transition elements, presenting the optimized interfacial impedance matching. As an example, the FeCoNiTiMn HEA@C-NPs obtain the minimum reflection loss (RLmin ) of -33.4 dB at 7.0 GHz (3.34 mm) and the efficient absorption bandwidth (≤-10 dB) of 5.45 GHz ranging from 12.55 to 18.00 GHz with an absorber thickness of 1.9 mm. The present approach can be extended to other carbon-coated complex components systems for various applications.

Spontaneous Formation of Ordered Magnetic Domains by Patterning Stress.

The formation of ordered magnetic domains in thin films is important for the magnetic microdevices in spin-electronics, magneto-optics, and magnetic microelectromechanical systems. Although inducing anisotropic stress in magnetostrictive materials can achieve the domain assembly, controlling magnetic anisotropy over microscale areas is challenging. In this work, we realized the microscopic patterning of magnetic domains by engineering stress distribution. Deposition of ferromagnetic thin films on nanotrenched polymeric layers induced tensile stress at the interfaces, giving rise to the directional magnetoelastic coupling to form ordered domains spontaneously. By changing the periodicity and shape of nanotrenches, we spatially tuned the geometric configuration of domains by design. Theoretical analysis and micromagnetic characterization confirmed that the local stress distribution by the topographic confinement dominates the forming mechanism of the directed magnetization.

Wrinkled Titanium Carbide (MXene) with Surface Charge Polarizations through Chemical Etching for Superior Electromagnetic Interference Shielding.

Despite the fact that the high conductivity of two-dimensional laminated transition metal carbides/nitrides (MXenes) contributes to the outstanding electromagnetic interference (EMI) shielding by the reflection of electromagnetic waves (EWs), it is difficulty to improve EMI shielding by pursuing higher conductivity due to the limitation of intrinsic properties. Here, we achieve superior EMI shielding by introducing the absorption of EWs in MXenes with micro-sized wrinkles which are induced by abundant Ti vacancies under chemical etching. The shielding effectiveness is up to 107 dB at a thickness of 20 µm. Combining with atomic-scale structure observation and the first-principles calculations, it is concluded that the promotion of EMI shielding originates from the resonant absorption of formed electric dipoles induced by the asymmetrical distribution of charge densities near Ti vacancies. Our results could open a new vista for developing two-dimensional EMI shielding materials.

High-Entropy-Alloy Nanoparticles with Enhanced Interband Transitions for Efficient Photothermal Conversion.

Photothermal materials with broadband optical absorption and high conversion efficiency are intensively pursued to date. Here, proposing by the d-d interband transitions, we report an unprecedented high-entropy alloy FeCoNiTiVCrCu nanoparticles that the energy regions below and above the Fermi level (±4 eV) have been fully filled by the 3d transition metals, which realizes an average absorbance greater than 96 % in the entire solar spectrum (wavelength of 250 to 2500 nm). Furthermore, we also calculated the photothermal conversion efficiency and the evaporation rate towards the steam generation. Due to its pronounced full light capture and ultrafast local heating, our high-entropy-alloy nanoparticle-based solar steam generator has over 98 % efficiency under one sun irradiation, meanwhile enabling a high evaporation rate of 2.26 kg m-2 h-1 .

Regulating the magnetic skyrmion in a confined nanochannel under a gradient magnetic field.

A magnetic skyrmion could be endowed with various dynamic magnetic configurations and behaviors. By artificially generating a gradient magnetic field in a confined nanochannel, we have shown the magnetic dynamics of an isolated skyrmion, achieving the coexistence of moving and breathing modes. Such a phenomenon has been proven to be not only correlated to the gradient strength of a magnetic field, but also depends on the Dzyaloshinskii-Moriya interaction. By increasing the magnetic field gradient up to 0.1 mT nm-1, the skyrmion can effectively overcome the skyrmion Hall effect, and meanwhile generate a breathing mode during the motion process under MFG = 1.0 mT nm-1 and DMI = 2.8 mJ m-3. The present study could provide an alternative approach to regulate the skyrmion at micro/nanoscales by using a gradient magnetic field.

nm23-H1 is a negative regulator of TGF-ß1-dependent induction of epithelial-mesenchymal transition.

Members of transforming growth factor-ß(TGF-ß) family are the main inducers of epithelial-mesenchymal transition (EMT) during embryogenesis and cancer pathogenesis. However, a significant crosstalk between TGF-ß and other signals occurs during the induction of EMT. nm23-H1 was the first metastasis suppressor gene to be identified on the basis of an inverse relationship between nm23-H1 expression and metastasis stage. Despite extensive studies, the mechanism underlying its ability to suppress metastasis is far from elucidated. We demonstrated here that the nm23-H1 negatively regulated TGF-ß1-dependent induction of EMT in non-aggressive lung cancer cell line. nm23-H1 knockdown significantly enhanced TGF-ß1-induced suppression of epithelial marker E-cadherin and upregulation of mesenchymal markers ß-catenin and fibronectin. The invasive and migratory potential of lung cancer cells upon TGF-ß1 treatment was also markedly enhanced by nm23-H1 knockdown. On the other hand, the effect of nm23-H1 depletion on TGF-ß1-induced EMT was reversed by ectopic re-expression of shRNA-resistant nm23-H1 protein. Furthermore, TGF-ß1-induced EMT potentiated by nm23-H1 depletion was partially dependent on transcriptional factor Snail expression. Finally, we found Src kinase is involved in regulation of TGF-ß1-induced EMT by nm23-H1. Our results suggest a means of restoring nm23-H1 to suppress TGF-ß1-induced EMT that may exploited therapeutically for the management of metastasis diseases.

Highly anisotropic Fe3C microflakes constructed by solid-state phase transformation for efficient microwave absorption.

Soft magnetic materials with flake geometry can provide shape anisotropy for breaking the Snoek limit, which is promising for achieving high-frequency ferromagnetic resonances and microwave absorption properties. Here, two-dimensional (2D) Fe3C microflakes with crystal orientation are obtained by solid-state phase transformation assisted by electrochemical dealloying. The shape anisotropy can be further regulated by manipulating the thickness of 2D Fe3C microflakes under different isothermally quenching temperatures. Thus, the resonant frequency is adjusted effectively from 9.47 and 11.56 GHz under isothermal quenching from 700 °C to 550 °C. The imaginary part of the complex permeability can reach 0.9 at 11.56 GHz, and the minimum reflection loss (RLmin) is -52.09 dB (15.85 GHz, 2.90 mm) with an effective absorption bandwidth (EAB≤-10 dB) of 2.55 GHz. This study provides insight into the preparation of high-frequency magnetic loss materials for obtaining high-performance microwave absorbers and achieves the preparation of functional materials from traditional structural materials.

Metastasis suppressor Nm23-H1 inhibits STAT3 signaling via a negative feedback mechanism.

Persistent STAT3 activation is a critical event in tumorigenesis and metastatic progression. Recent studies have found higher levels of STAT3 in metastatic tissues than in primary tumor tissues. We speculated that such increased STAT3 activity might be attributed to a loss of function or reduction in expression of metastasis inhibitory protein during cancer progression, and we therefore examined the role of tumor metastasis-suppressor nm23-H1 in the activation of STAT3 in the A549 lung cancer cell line. We found that IL-6-dependent induction of tyrosine phosphorylation and activation of STAT3 were influenced by nm23-H1 inhibition. IL-6-induced STAT3(Tyr705) phosphorylation was significantly enhanced in A549 cells transfected with siRNA specific for nm23-H1, and the effect of nm23-H1 depletion on IL-6-induced STAT3(Tyr705) phosphorylation was reversed by ectopic expression of shRNA-resistant nm23-H1 protein. Moreover, STAT3 directly bound to the STAT3 binding site on the nm23-H1 promoter and activated its expression. Thus, we have identified a new feedback mechanism that might provide insight into an in-built metastasis-suppression function in tumor cells and which could be a logical new target for treatment of early metastatic disease.

Intrinsically High Magnetic Performance in Core-Shell Structural (Sm,Y)Fe12 -Based Permanent Magnets.

ThMn12 -type SmFe12 -based permanent magnets have exhibited great potential in advanced magnet motors because of their high temperature stability of magnetic properties. However, the applications could be seriously limited due to the trade-off between phase stability and intrinsic magnetic properties. In this work, an effective solution is demonstrated by constructing the core-shell structure (Sm-rich shell and Y-rich core) via a spontaneous spinodal decomposition process. The anisotropy field for the (Sm0.75 Y0.25 )(Fe0.8 Co0.2 )11.25 Ti0.75 alloy is mostly optimized to be 9.24 T at room temperature. Such an enhancement is ascribed to the pinning process of domain walls by the magnetic-hardening Sm-rich shell, which is directly observed by in situ Lorentz transmission electron microscopy and reconstructed by micromagnetic simulation. Moreover, the phase stability and saturation magnetization are simultaneously increased, which is attributed to the synergistic effect of Y, Co, and Ti substitutions. More importantly, the high µ0 Ms value of 1.52 T is comparable to the reported (Sm,Zr)Fe12 -based bulk alloys that contain a larger amount of soft α-Fe phases, indicating that this strategy is more promising toward bulk magnets. The present study provides a significant concept for the development of advanced permanent magnets and also has implications for understanding the structural origin of intrinsic magnetic configurations.

High-entropy-alloy nanoparticles with 21 ultra-mixed elements for efficient photothermal conversion.

Multi-metallic nanoparticles have been proven to be an efficient photothermal conversion material, for which the optical absorption can be broadened through the interband transitions (IBTs), but it remains a challenge due to the strong immiscibility among the repelling combinations. Here, assisted by an extremely high evaporation temperature, ultra-fast cooling and vapor-pressure strategy, the arc-discharged plasma method was employed to synthesize ultra-mixed multi-metallic nanoparticles composed of 21 elements (FeCoNiCrYTiVCuAlNbMoTaWZnCdPbBiAgInMnSn), in which the strongly repelling combinations were uniformly distributed. Due to the reinforced lattice distortion effect and excellent IBTs, the nanoparticles can realize an average absorption of >92% in the entire solar spectrum (250 to 2500 nm). In particular, the 21-element nanoparticles achieve a considerably high solar steam efficiency of nearly 99% under one solar irradiation, with a water evaporation rate of 2.42 kg m-2 h-1, demonstrating a highly efficient photothermal conversion performance. The present approach creates a new strategy for uniformly mixing multi-metallic elements for exploring their unknown properties and various applications.

Transparent and Flexible Electromagnetic Interference Shielding Materials by Constructing Sandwich AgNW@MXene/Wood Composites.

Electromagnetic interference (EMI) shielding materials have attracted intensive attention with the increased electromagnetic pollution, which are required to possess high transparency and flexibility for applications in visualization windows, aerospace equipment, and wearable devices. However, it remains a challenge to achieve high-performance EMI shielding while maintaining excellent light transmittance. Herein, a sandwich composite is constructed by coating the core material of transparent wood (TW) with silver nanowire (AgNW)@MXene, exhibiting a maximum transmittance of 28.8% in the visible range and a longitudinal tensile strength of 47.8 MPa. The average EMI shielding effectiveness can reach up to 44.0 dB under X-band (8-12.4 GHz), ascribed to the increased absorption shielding induced by the multireflection of electromagnetic waves within microchannels of the TW layer and the interfacial polarization between AgNW and MXene. Simultaneously, large-scale EMI shielding films can be conveniently produced by our proposed method, which provides inspiration for the development of advanced EMI shielding materials for wide applications.

Transformation from antiferromagnetic target skyrmion to antiferromagnetic skyrmion by unzipping process through a confined nanostructure.

The manipulation of magnetic skyrmion has been attracting considerable attention for the fundamental physical perspective and promising applications in spintronics, ascribed to their nontrivial topology and emergent electrodynamics. However, there is a hindrance to the transmission of a skyrmion in the racetrack memory due to the skyrmion Hall effect (SHE). Antiferromagnetic (AFM) materials provide a possibility to overcome the SHE in high-velocity data writing. Herein, we systematically investigate the generation and motion of an AFM target skyrmion under the spin-polarized current. We found that the AFM target skyrmion can reach a velocity of 1088.4 m s-1under the current density of 8 × 1012 A m-2, which is lower than 1269.8 m s-1for the AFM skyrmion. This slowdown can be ascribed to the deformation of AFM target skyrmion in the process of motion on a nanotrack. In addition, we observed a transformation from AFM target skyrmion to AFM skyrmion by the unzipping process through a constricted nanostructure which is mediated by the formation of AFM domain wall. Two energy barriers need to be overcome in this dynamic process, i.e. 2.93 × 104 eV from AFM target skyrmion to AFM domain wall, and 7.625 × 103 eV from AFM domain wall to AFM skyrmion. Our results provide guidance for future target skyrmion-based devices.

Factors influencing the hospitalization costs of patients with type 2 diabetes.

This study aims to research the factors influencing the hospitalization costs of patients with type 2 diabetes, so as to provide some references for reducing their economic burden. Based on the Hospital Information System of a 3A grade hospital in China, we analyzed 2970 cases with type 2 diabetes during 2005-2012. Both the number of inpatients and the hospitalization costs had increased in the study period. Using multiple linear regression analysis, we found that patients in Urban Employee Basic Medical Insurance had higher costs than those in New Rural Cooperative Medical Scheme. We also found hospitalization costs to be higher in male patients and older patients, patients who stayed more days at hospital and who had surgeries, patients who had at least 1 complication, and patients whose admission status was emergency. After standardizing the regression coefficients, we found that the hospital stay, the forms of payment, and presence of complications were the first 3 factors influencing hospitalization costs in our study. In conclusion, the hospitalization costs of patients with type 2 diabetes could be influenced by age, gender, forms of payment, hospital stay, admission status, complications, and surgery. Medical workers in the studied region should take actions to reduce the duration of hospital stay for diabetic patients and prevent relevant complications. What is more, medical insurance needs further improvement.

Generation and distribution of PAHs in the process of medical waste incineration.

After the deadly earthquake on May 12, 2008 in Wenchuan county of China, several different incineration approaches were used for medical waste disposal. This paper investigates the generation properties of polycyclic aromatic hydrocarbons (PAHs) during the incineration. Samples were collected from the bottom ash in an open burning slash site, surface soil at the open burning site, bottom ash from a simple incinerator, bottom ash generated from the municipal solid waste (MSW) incinerator used for medical waste disposal, and bottom ash and fly ash from an incinerator exclusively used for medical waste. The species of PAHs were analyzed, and the toxicity equivalency quantities (TEQs) of samples calculated. Analysis results indicate that the content of total PAHs in fly ash was 1.8×10(3) times higher than that in bottom ash, and that the strongly carcinogenic PAHs with four or more rings accumulated sensitively in fly ash. The test results of samples gathered from open burning site demonstrate that Acenaphthylene (ACY), Acenaphthene (ACE), Fluorene (FLU), Phenanthrene (PHE), Anthracene (ANT) and other PAHs were inclined to migrate into surrounding environment along air and surface watershed corridors, while 4- to 6-ring PAHs accumulated more likely in soil. Being consistent with other studies, it has also been confirmed that increases in both free oxygen molecules and combustion temperatures could promote the decomposition of polycyclic PAHs. In addition, without the influence of combustion conditions, there is a positive correlation between total PCDD/Fs and total PAHs, although no such relationship has been found for TEQ.

[Epithelial-mesenchymal transition and tumor metastasis].

Metastasis is the transfer of malignant tumors from one organ to a distant organ. It is the most common cause of death in cancer patients. Different molecular mechanisms enable tumor cells to infiltrate the surrounding tissue, invade blood vessels and leave the blood stream at a different site. Epithelial-mesenchymal transition (EMT) is critical for appropriate embryonic development, and this process is re-engaged in adults during wound healing, tissue regeneration, organ fibrosis, and cancer progression. EMT is the first step in tumor invasion and metastasis. A detailed knowledge of the molecular requirements for EMT in human cancer will help us to better understand tumor progression and to delineate more effective strategies for future therapeutic intervention.

[Separation of correctly refolded and mis-refolded consensus interferon by hydrophobic interaction chromatography].

Hydrophobic interaction chromatography was used to separate correctly refolded and mis-refolded consensus interferon. The effects of ligand types, salt concentration, pH and flow rate were investigated. The best result could be obtained by using Butyl Sepharose 4 Fast Flow, 0.8 mol/L of ammonium sulfate, pH 8.3 and 90cm/h of linear flow rate. Reverse-phase HPLC analysis showed the purity of the pooled fraction was as high as 99.6%. The specific activity of purified consensus interferon was 2.3 x 10(9) IU/mg, The mass recovery of targeth protein was 36.7%.