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Nontoxic lead-free multiferroic composites are synthesized by incorporating the dispersed 0.3CoFe2O4 (CFO) ferromagnetic nanoparticles into 0.7(K0.5Na0.5) NbO3-LiSbO3 (KNN-LS5.2) ferroelectric micromatrix. The multiferroicity of the composite can be verified by polarization-electric field hysteresis loop and magnetic hysteresis loop. The composite exhibits excellent magnetic properties. A dilution effect is observed in magnetic hysteresis loops. The field dependence of ME voltage coefficient is given as a function of magnetic field from -4 kOe to 4 kOe with a maximum magnetoelectric voltage coefficient of 10.7 mV⋅cm-1⋅Oe-1 at the frequency of 1 kHz. It is a very high value in the lead-free magnetoelectric composites system for the potential use on multifunctional devices. [ABSTRACT FROM AUTHOR]

Effect of bivalent cation Ca-doping on magnetic properties in multiferroic YMnO3 manganites was systemically studied by DC and AC magnetic measurements. Series of samples were prepared by solid-state reaction method with composition Y1− xCa xMnO3 ( x= i/8, i=2,3,...,7). The results show that each of the zero-field-cooling (ZFC) curves has a clear cusp and it shifts to higher temperature with increasing Ca-doping x. From the χ−1– T curve, the temperature of charge-ordering (CO) state TCO is given at about 244.0 K and this indicates that the CO state is dominated by the cooperative Jahn–Teller effect in Y1/2Ca1/2MnO3 with small A-site cation, for which there is a different behavior compared to the other manganites of larger 〈 r A〉. When x=2/8 and 7/8 for Y1− xCa xMnO3, the magnetization curve shows strong irreversibility between ZFC and FC data. The variation of AC susceptibility presents a maximum cusp at the beginning temperature of the bifurcation between ZFC and ZF curve and shifts to higher temperature with increasing measurement frequency for AC susceptibility. These results can be characterized by spin-glass, indicating that much more itinerant eg electrons are promoting the magnetic transition. [ABSTRACT FROM AUTHOR]

Abstract: Multiferroic ErCrO3 was synthesized and the detailed magnetic as well as ferroelectric properties were investigated. The dc magnetization shows that ErCrO3 undergoes a antiferromagnetic ordering at T N =133K due to the Cr3+–Cr3+ followed by weak ferromagnetic ordering. Around T SR ≈22K, ErCrO3 exhibits a spin reorientation from Γ4 to Γ1. And the stability of the ferromagnetic Γ4 phase increases with the applied magnetic field increasing. Furthermore, at lower temperature, it shows weak antiferromagnetic ordering of Er3+. We also present the low temperature polarization data for ErCrO3 and find a remarkable decreasing of polarization around T N =133K on increasing temperature, this effect might be due to the coupling between magnetic and ferroelectric order parameters, and the magnetic field suppresses the polarization which demonstrates convincingly the strong magnetoelectric (ME) coupling in ErCrO3. [Copyright &y& Elsevier]

Abstract: The effects of rare-earth ionic size on the local electron structure, lattice parameters and superconductivity have been investigated by positron annihilation technique (PAT) and related experiments for RBa2Cu3O7−δ (R=Tm, Dy, Gd, Eu, Nd and Y) superconductors. The local electron density n e is evaluated as a function of the rare-earth radius. The results show that both the bulk-lifetime τ B and the defect lifetime τ 2 increase with increasing rare-earth ionic radius, while the local electron density n e decrease with increasing rare-earth ionic radius. These results prove that the changes of n e, the degree of orthorhombic distortion and the coupling between the Cu–O chains and the CuO2 planes all have an effect on the superconductivity of RBa2Cu3O7−δ systems. [Copyright &y& Elsevier]

• At present, there are no papers about Mn doping CaBaCo 4 O 7. • Mn-doping weakened the FIM interaction. • Few reports focused on the effects of valence states on properties of Ni-doped. • Ni-doping enhances the antiferromagnetic interaction. • Ni-doping induces an additional antiferromagnetic phase. • Both Mn doping and Ni doping enhance the magnetodielectric effect of the sample. We reported the magnetic and dielectric properties of the polar magnet CaBaCo 4- x Mn x O 7 and CaBaCo 4- x Ni x O 7 (x = 0.04, 0.08). The result shows that Mn ions exist in the sample in + 2 and + 3 valence, replacing both Co2+ and Co3+, and the Ni ions exist in + 2 valence, only replacing Co2+. Mn ion doping does not change the ratio of Co2+ to Co3+ in the crystal, leading to similar magnetic behavior to CaBaCo 4 O 7. Ni ions increase the relative content of Co3+, which has a greater damage to the ferromagnetic interaction. Meanwhile, Mn-doping can partially release the magnetic frustration and cause the spin freezing temperature shifting to high temperature. It also slightly weakened the FIM interaction in the sample. While Ni-doping enhances the antiferromagnetic interaction and induces an additional antiferromagnetic phase at 82 K in the sample. The dielectric behavior of all samples is obviously abnormal at magnetic phase transitions, which proves the magnetodielectric effect of the samples. After Mn and Ni ions doping, the magnetodielectric properties of the samples are improved. Compared with Mn ions, Ni ions have a greater effect on the dielectric properties of CaBaCo 4 O 7. [ABSTRACT FROM AUTHOR]

The Ca3CoMn1-xTixO6(x = 0, 0.05) samples were synthesized by a modified sol-gel method, and the microstructure, microtopography, and magnetic properties were investigated in detail. With substituting of Mn4+ ions by Ti4+ ions, the crystallinity and particle size of Ca3CoMn1-xTixO6 (x = 0, 0.05) samples decrease. The Ti4+ doping also causes the high-temperature spin freezing phenomenon disappears, and the transition field of ↑↑↓↓ magnetic structure to ↑↑↑↓ magnetic structure increases obviously together with the faster dynamic behavior. These results suggest that the dilution effect of Ti4+ doping to Co-Mn-Co-Mn spin chains could reduce the degree of magnetic frustration and suppress the formation of short range magnetic order, for which will be beneficial for the establishment of more robust long range antiferromagnetic structure. The present research could serve as a reference on tuning the magnetic order and improving the multiferroic property of Ca3CoMnO6. [ABSTRACT FROM AUTHOR]

• The introduction of defects could directly reflect the influence and contribution of ions to the properties of materials. • The Co defects destroy the Co-Co exchange interactions, it has an obvious dilution effect on the FM interaction. • The weakened ferromagnetic interaction results in that disordered magnetic correlations become long-range FM order. • The Co-defective Ca 3 Co 2 O 6 compound has a strong magnetodielectric coupling effect. The Ca 3 Co 2 -x O 6 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.1) samples were prepared by reducing the stoichiometric ratio of Co atoms. Their structure, magnetic properties, dielectric and magnetodielectric properties were investigated. XRD results show that the presence of a small number of vacancies does not change the crystalline structure. The positive Curie-Weiss temperature θ and interchain exchange constants J indicate that ferromagnetic interactions are stronger than the antiferromagnetic interactions in Co-defective Ca 3 Co 2 -x O 6. The Co-vacancies could weaken the Co-Co exchange interactions, it has an obvious dilution effect on the ferromagnetic interactions within the chain. The magnetization steps move to low field accompanying the defects increase. Simultaneously, Co defects could also release part of the magnetic frustration. The competition of the released magnetic frustration and the dilution effect of the vacancies to the ferromagnetic chains and low doping concentration make the Co-defective Ca 3 Co 2 -x O 6 present similar magnetic property with the parent Ca 3 Co 2 O 6. At the positions of magnetic phase transition and the critical magnetic field of magnetization steps, clear dielectric anomalies can be detected. This result suggests the strong magnetodielectric coupling effect in Ca 3 Co 2 -x O 6 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.1) samples. [ABSTRACT FROM AUTHOR]

The incompatibility between the antiferromagnetic exchange interaction and the triangular lattice makes Ca 3 Co 2 O 6 become a frustrated system. It leads to the existence of disordered magnetic structure in the frustrated spin chains. At low temperature, the disordered spins are frozen. In this study, the Ca 3 Co 2 O 6 was prepared and its low temperature dynamic behaviors were characterized. The spin freezing peak and the decay of magnetization with time well confirm the thermally assisted magnetization. Since that the flip of the spins can result in the conservation of the total angular momentum and the conserved angular momentum can make the adjacent lattice feel a transfer torque. In response to variation of magnetization, the dielectric permittivity of Ca 3 Co 2 O 6 also presents relaxation feature. For the isothermal dielectric permittivity, it not only depends greatly on the sweep rates of magnetic field but also decays with time. This detectable variation of the dielectric property in Ca 3 Co 2 O 6 suggests that the thermally assisted dielectric relaxation is an alternative method for characterizing the dynamic behaviors of the frustrated system. • Spin-freezing peaks and magnetization intensity decay with time. • The presence of thermally assisted magnetization intensity is well confirmed. • The dielectric permittivity of Ca 3 Co 2 O 6 also presents relaxation feature. • The isothermal dielectric constant depends on the sweep of the magnetic field and decays with time. • The thermally assisted dielectric relaxation is alternative way for characterizing dynamic behavior of frustrated system. [ABSTRACT FROM AUTHOR]

We report a detailed study of the influence of non-magnetic Al3+ doping on the microstructure, magnetic, and dielectric characteristics Ca 3 CoMnO 6. The introduction of Al3+ leads to the suppression of competing short-range magnetic orders, a gradual disappearance of the spin freezing peak in Ca 3 CoMn 1- x Al x O 6 was observed, accompanied by the release of magnetic frustration. Moreover, a weakening of the antiferromagnetic order in Ca 3 CoMnO 6 was attributed to the dilution effect induced by non-magnetic Al3+ within the Co-Mn-Co-Mn spin chains. The dielectric measurements exhibit excellent agreement with the magnetic measurements. The substitution of Mn4+ with Al3+ results in the attenuation of relaxor ferroelectric behavior, accompanied by a decrease in the static freezing temperature T f and an increase in the activation energy E a. It indicates that Al3+ substitution could well suppress the formation of polar nanoregions. With introducing Al3+ the magnetodielectric effect of Ca 3 CoMnO 6 is also significantly enhanced. For the x = 0.15 sample, the magnetodielectric effect undergoes a notable variation of approximately 10 % under a magnetic field of H = 4 T. • A weakening of the antiferromagnetic order in Ca 3 CoMnO 6 is induced by the increase in the Al3+ doping level. • The substitution of Mn4+ with Al3+ results in the attenuation of relaxor ferroelectric behavior. • The magnetodielectric effect of Ca 3 CoMnO 6 is significantly enhanced by Al3+ doping. [ABSTRACT FROM AUTHOR]

Ca 3 Co 2- x Al x O 6 (x = 0, 0.02, 0.04, 0.06, 0.08 and 0.1) were prepared via the conventional sol-gel method. The structure, magnetic, dielectric and magnetodielectric properties were investigated. The Rietveld structural refinement confirms the rhombohedral structure of the samples. The positive Curie-Weiss temperature θ and magnetic coupling exchange constants J indicate the dominant intrachain ferromagnetic interactions in the spin chains. The obvious inhibition effect to equally spaced magnetization steps demonstrates that Al3+ could release the magnetic frustration. With Al3+ substitution, both the magnetization intensity and the critical field of the ferrimagnetism to ferromagnetism transition decrease. The samples present obvious dielectric anomalies around the Curie temperature T c and the freezing temperature T f. Meanwhile, the magnetic field dependence of dielectric permittivity decreases suddenly at critical magnetic fields. These results reveal strong magnetodielectric coupling effect in Ca 3 Co 2- x Al x O 6. The same sign of Δε r and Δtanδ suggests that the magnetodielectric coupling effect is intrinsic. [ABSTRACT FROM AUTHOR]

Pure ZnO and Cu-doped ZnO powders (i.e. Cu = 0, 0.5, 1, 1.5 and 2 at.%) have been prepared by a coprecipitation method and annealed in O 2 , N 2 and air. The role of atmosphere and doping in structure and magnetism has been investigated by x-ray diffraction (XRD), Raman spectrum and magnetic measurement. The XRD and Raman results indicate that the undoped and Cu-doped samples below 1 at.% are pure phase with the ZnO wurtzite structure. The undoped samples show unexpected room-temperature ferromagnetism (RTFM) with a strong diamagnetic background. The unsaturation hysteresis loops of the samples prepared in oxygen-poor atmospheres such air and N 2 indicates that oxygen vacancy (V O) prefers to increase paramagnetic component instead of stabilizing the ferromagnetic ordering. This result demonstrates that V O does not play an importance role to inducing the observed RTFM, which is very different from recent experimental and theoretical results. Cu doping has suppressed the diamagnetic background and caused a significant increase of saturation magnetization (M S), i.e. as the x increases from 0 to 1.5 at.%, the M S of the samples annealed in O 2 increases from 5 × 10−4emu/g to 6.5 × 10−3emu/g in an applied field of 5000 Oe. It strongly indicates that Cu doping can enhance the RTFM, which could be ascribed to the additional magnetic interaction associated to the unpaired d electrons of Cu ions. • The ZnO powder samples without dopant can be ferromagnetism at room temperature. • The oxygen vacancy does not play an essential role to generating the observed RTFM in the pure ZnO samples. • The solid solubility of Cu in ZnO matrix is less than 1.5 at.%. • Cu doping can suppress the diamagnetism of ZnO matrix and enhance the ferromagnetism. [ABSTRACT FROM AUTHOR]

Highlights • A high efficient, high power gas THz laser based on L-shaped cavity is present. • THz output performance was investigated both in theory and experiment. • The optimum output coupling is 0.8 and the optimum gas pressure is 500 Pa. • The maximum THz pulse energy is 8.4 mJ under the pumping energy of 1.6 J. Abstract A high power gas terahertz laser based on L-shaped cavity was demonstrated. We, for the first time, investigated the output performances of D 2 O gas 385 μm THz laser by optimizing the output coupler transmittance of the L-shaped cavity both in theory and experiment. Under the pump energy of 1.6 J, the optimum output coupler transmittance was about 0.78 and the optimum gas pressure was about 500 Pa. Up to 8.4 mJ pulse energy at 385 μm was achieved at output coupler transmittance of 0.8, corresponding to a photon conversion efficiency of 43.7%. Pulse width of 120 ns, and beam quality factor M2 of 1.58 were obtained at the highest output energy. In addition, the experimental results are in agreement with the theoretical simulation results. [ABSTRACT FROM AUTHOR]

The introduction of defects is the key method to control the multiferroic properties of one-dimensional frustration Ca 3 CoMnO 6. In this work, we synthesized a series of Ga3+ doped Ca 3 CoMn 1- x Ga x O 6 (x = 0, 0.05, 0.1, 0.2) compounds. Their crystallographic structure, magnetism as well as the dielectric properties were characterized. The XRD patterns verify the rhombohedral structure of all the samples. The Ga3+ ions have obvious inhibitory effect on the magnetic short-range order. With the substitution of Mn4+ by Ga3+, the polar nanodomains are inhibited and the diffusion index γ becomes lower. The same sign of Δε' and Δtanδ in magnetic field dependent permittivity suggests that the magnetoelectric coupling effect in Ca 3 CoMn 1- x Ga x O 6 is intrinsic. For the Ca 3 CoMn 1- x Ga x O 6 system, the freezing process is primarily dominated by the coupling of the polar nanodomains. • Ga3+ ions play a significant role in suppressing the short-range magnetic correlation. • The same sign of Δε' and Δtanδ in magnetic dependent permittivity shows magnetoelectric coupling effect is intrinsic. • The introduction of Ga3+ could inhibit the formation of polar nanodomains. [ABSTRACT FROM AUTHOR]

The Cr-doped Ca 3 CoMn 1- x Cr x O 6 (x= 0, 0.05, 0.1, 0.15) polycrystalline samples were prepared using a modified sol-gel method. The structural, magnetic and dielectric properties were systemically investigated. With increasing Cr3+-doping level, the partial Co2+ ions change to Co3+, leading to a decreased lattice volume. Correspondingly, the length of the short-range magnetic correlation is inhibited and a faster dynamic behavior in time dependent magnetization is found. At the benefit of the magnetic structural changes with the introduction of Cr3+ ions, the relaxor degree of the ferroelectric transition that induced by the exchange striction becomes lower, while the activation energy of the frozen polar-nanoregions increases. The replacement of Mn4+ by Cr3+ also leads to a reduced intra-chain antiferromagnetic coupling and the emergence of Co3+-Co3+ ferromagnetic interaction. As consequence, the Curie-Weiss temperature (θ) increases monotonously. The variation in dielectric permittivity with magnetic field confirms the existence of large magnetodielectric coupling in the Ca 3 CoMn 1- x Cr x O 6 (0 ​≤ ​ x ​≤ ​0.15) samples. Especially for the x ​= ​0.15 sample, the permittivity changes by about 7% under the magnetic field of H= 4 ​T. Replacement of Mn4+ by Cr3+ in Ca 3 CoMnO 6 makes part of Co2+ change to Co3+ and the magnetic structure can be modified. Thus, the degree of the ferroelectric relaxation becomes lower, implying that introduction of Cr3+ could help to improve the ferroelectricity. Large magnetodielectric coupling is also verified in Cr3+ doped samples. For x ​= ​0.15 sample, the permittivity changes by 7% under H ​= ​4 ​T. [Display omitted] • Replacement of Mn4+ by Cr3+ makes part of Co2+ change to Co3+. • The magnetic structure can be modified by Cr3+-doping. • The degree of the ferroelectric relaxation becomes lower. • The Cr3+-doped could improve the ferroelectricity. • Large magnetodielectric coupling is verified in Cr3+ doped samples. [ABSTRACT FROM AUTHOR]

A series of Ni2+ doped Ca 3 Co 1- x Ni x MnO 6 (0 ≤ x ≤ 0.15) samples were prepared for this study. Their structure, magnetism and electrical properties were investigated. The results show that the spin of Ni2+ is antiferromagnetically coupled to the neighbor Mn4+ cations. In Ni2+ substituted samples, the short-range magnetic correlation is inhibited and the long-range antiferromagnetic structure is strengthened. Due to the random distribution of Ni2+ substitution in Co2+ sites, the macroscopical ferroelectric domains of Ca 3 CoMnO 6 are destroyed and more polar nanoregions form. With the increase of Ni2+ content, the relaxor behavior of the ferroelectric transition becomes stronger and the activation energy E a decreases monotonously. The enhanced antiferromagnetic interaction also reinforces the dipole correlation, leading to the increased static freezing temperature T f in Ni2+ doped samples. Magnetodielectric coupling is significantly improved due to the magnetic structural variation produced by doping of compound with Ni2+ cations. For the x = 0 sample, the maximal deviation of the dielectric permittivity at H = 7 T relative to the value at H = 0 is about 2.25 %. While for the x = 0.1 and 0.15 samples, this value is 7.5 % at H = 7 T. • Doping with Ni2+ could strengthen the antiferromagnetic interaction effectively. • The Ni2+ doped samples present stronger relaxor ferroelectric nature. • The magnetoelectric coupling effect is much improved in Ni2+ doped samples. [ABSTRACT FROM AUTHOR]

The typical ↑↑↓↓ spin order of the one-dimensional frustrated Ca 3 CoMnO 6 breaks the inversion symmetry and results in the ferroelectricity. But the previous calculations predict a much larger ferroelectric polarization than the experimental observation. To comprehend the divergence, Ca 3 CoMnO 6 ceramics were prepared and the magnetic, dielectric properties were studied. In accordance with the formation of short range magnetic correlation, around the antiferromagnetic transition temperature T N the Ca 3 CoMnO 6 ceramics present weak relaxor ferroelectric nature. It implies the existence of polar nanoregions. Thus, the destruction of long range ferroelectric order and the formed polar nanoregions should be responsible for the suppressed macroscopic ferroelectric polarization. The activation energy and static freezing temperature of Ca 3 CoMnO 6 are also calculated. The obtained values are E a = 6.31 × 10−3 eV and T f = 1.5 K, respectively. Both of them are lower about two orders of magnitude than the conventional relaxor ferroelectrics. Magnetic field dependent dielectric permittivity manifests the large magnetodielectric coupling of Ca 3 CoMnO 6. Under the application of field of 7 T, the dielectric permittivity reduces by about 10%. • Around the antiferromagnetic transition temperature T N the Ca 3 CoMnO 6 ceramics present weak relaxor ferroelectric nature. • The Ca 3 CoMnO 6 ceramicspresent weak relaxor ferroelectric nature. • Magnetic field dependent dielectric permittivity manifests the largemagnetodielectric coupling. [ABSTRACT FROM AUTHOR]

Abstract: A new kind of lead-free multiferroic magnetoelectric composites was successfully prepared by incorporating the dispersed CoFe2O4 (CFO) ferromagnetic nanoparticles into (K0.5Na0.5)NbO3–LiSbO3 (KNN-LS5.2) ferroelectric micromatrix. The dependence of dielectric properties and DC magnetization on CFO phase content was systemically studied. The results show that the dielectric constant decreases with increasing CFO phase content at higher frequencies while the loss tangent and the magnetic moment increase with it. Variation of dielectric constant and dielectric loss with frequency also showed dispersion in the low frequency range, and the values of (ɛ r max − ɛ r min )/ɛ r max increase with the increase in ferrite CFO content. The value of H bias corresponding to α E max almost linearly increases with the increase in ferrite CFO content in composites. We can conclude that the main reasons of dispersion were correlative with the heterogeneous conduction in the multiphase structure of the composites. A maximum magnetoelectric voltage coefficient of 15.01mVcm−1 Oe−1 was observed from the composites with 40mol% CFO at 1kHz, which was a very high value in the lead-free magnetoelectric composite system for the potential use on actuators and sensors, etc. [Copyright &y& Elsevier]

(a) The M t /M t=0 curves of the Ca 3 Co 1+ x Mn 1- x O 6 (x = 0, 0.05, and −0.05) samples measured by ZFC after cooling the samples to 5 K, switching on a 5 T field, and then recording the magnetization as a function of the time. (b) The M t /M t=0 curves measured by first magnetizing the samples in H = 5 T at T = 5 K, switching off the magnetic field, and then recording the remnant magnetization. • Structure and magnetization of Co/Mn compensated Ca 3 Co 1+x Mn 1-x O 6 (x = 0, 0.05, −0.05) were investigated. • The short range magnetic correlation of Ca 3 Co 1+x Mn 1-x O 6 compounds can be suppressed by tuning the Co/Mn ratio. • The faster dynamic characteristics are manifested for x =−0.05 and x = 0.05 samples. A series of Ca 3 Co 1+ x Mn 1- x O 6 (x =0, 0.05, and −0.05) compounds were synthesized that crystallized into rhombohedral structures with space group R-3c. Compared with the parent compound (x =0), the freezing peak of the Co/Mn compensated samples (x =±0.05) shifted to lower temperatures and became smeared. In addition, the coercive field H c and remnant magnetization M r of the compensated samples measured at T =130 K also decreased. This study found that the short-range magnetic order of Ca 3 Co 1+ x Mn 1- x O 6 compounds could be suppressed by tuning the Co/Mn ratio. Due to the suppression, the freezing magnetic moments in the compensated samples easily reversed magnetic field direction. Therefore, compared with the x =0 sample, the time dependence of magnetization relaxation in the compensated samples exhibited a sharp decay rate, indicating fast dynamics. [ABSTRACT FROM AUTHOR]

Nano-VO 2 (M) samples were synthesized by annealing VO 2 (B) nanoparticles. The internal defects of nano-VO 2 (M) samples were characterized by positron annihilation spectroscopy, and the effects of microdefects and grain size on the phase transition properties were studied. The results indicate that 575 ​°C is the critical temperature for preparing pure phase VO 2 (M), and the morphology of the samples evolves gradually from nanorods to nanospheres with the increase of annealing temperature. With the increase of annealing temperature from 575 ​°C to 675 ​°C, the grain size of the nanospheres increases gradually, while the concentration and size of the microdefects decrease with the improvement of crystallinity. It is found that both the microdefects and grain size have opposite effects on the phase transition temperature of nano-VO 2 (M) samples. The grain size plays a leading role in the competition for the samples annealed at higher temperature, which makes the semiconductor-metal transition temperature lower. Image 1 • A stepwise transition from the precursor VO 2 (B) to VO 2 (M) is exhibited in a wide annealing temperature range of 450–675 ​°C. • Characterization of micro defects by positron lifetime spectroscopy. • At the critical temperature of 575 ​°C, the size and concentration of void defects in VO 2 will change abruptly. • The effects of grain size and defect concentration on the phase transition temperature of VO 2 (M) are competitive. [ABSTRACT FROM AUTHOR]

For the spin-chain compound Ca 3 CoMnO 6 , the perfect Co/Mn ionic order causes the lost of ↑↑↓↓ long-range antiferromagnetic order. The lost long-range magnetic order results in the emergence of short range magnetic correlation interaction, forming the so called "order by disorder" phenomenon. In present paper, nonmagnetic Ga3+-doped Ca 3 CoMn 1- x Ga x O 6 compounds were prepared. The influence of Ga3+ substitution on the structure and magnetic order of Ca 3 CoMn 1- x Ga x O 6 were investigated. It is found that the solid solubility of Ga3+ cation in Ca 3 CoMn 1- x Ga x O 6 is 0.2 < x < 0.3. With introducing of Ga3+ cation, the oxidation state of some Co cations changes from Co2+ to Co3+. Magnetization measurements reveal that doped with nonmagnetic Ga3+ weakens the formation of short range magnetic order and enhances the antiferromagnetic transition temperature. As a result, more robust long rang antiferromagnetic order is established and the transition field that causes the ↑↑↓↓ spin state of Co–Mn–Co–Mn chain to ↑↑↓↑ state increases obviously. Meanwhile, the shortened short range magnetic correlation in Ga3+ doped Ca 3 CoMn 1- x Ga x O 6 can be driven more easily by the thermal activation energy and a quicker dynamic behavior was observed in time windows. • A series of Ga3+-doped Ca 3 CoMn 1- x Ga x O 6 compounds were synthesized. Our result reveals that the solid solubility of Ga3+ cation in Ca 3 CoMnO 6 is between x= 0.2 and x= 0.3. • Magnetization measurements indicate that doping with nonmagnetic Ga3+ could weak the formation of short range magnetic order and increase the antiferromagnetic transition temperature. • With introducing of Ga3+ cations, more robust long rang antiferromagnetic order is established and the transition field that causes the ↑↑↓↓ spin state of Co–Mn–Co–Mn chain to ↑↑↓↑ state enhances obviously. • In Ga3+ doped Ca 3 CoMn 1- x Ga x O 6 , the short range magnetic order is suppressed and more robust long rang antiferromagnetic order is established. [ABSTRACT FROM AUTHOR]

Glioblastoma (GBM) is a common primary central nervous system tumor. The molecular mechanisms of glioma are unknown, and the prognosis is poor. Therefore, exploring the underlying mechanisms and screening for new prognostic markers and therapeutic targets is crucial. We utilized the weighted gene co-expression network analysis (WGCNA), Differentially Expressed Genes (DEGs), and LASSO-COX analysis to identify three target genes. Next, we constructed and evaluated a prognostic model, screening out COL8A1 as a risk gene. Through a sequence of cellular functional experiments, in vivo studies, and RNA sequencing, we delved into exploring the functional effects and molecular mechanisms of COL8A1 on GBM cells. Finally, the correlation between COL8A1 and tumor immune cells and different inflammatory responses was analyzed. Immunohistochemistry experiments revealed the influence of COL8A1 on macrophage polarization. The COL8A1 expression level was associated with the grade, prognosis, and tumor microenvironment (TME) of glioma. Functional experiments showed that COL8A1 inhibited GBM cell apoptosis and promoted migration, invasion, and proliferation in vitro and in vivo. We also found that COL8A1 promotes the epithelial-mesenchymal transition process and may mediate the activation of the ERK pathway through SHC1. In addition, immune infiltration analysis showed that COL8A1 was closely associated with macrophages in glioma tissues, significantly suppressing the signaling of M1-like -type macrophages and enhancing the signaling of M2-like -type macrophages. COL8A1 was first found to be associated with prognosis, progression, and immune microenvironment of glioma and may serve as a new marker of prognosis and a therapeutic target., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Few-shot learning (FSL) is a challenging yet promising technique that aims to discriminate objects based on a few labeled examples. Learning a high-quality feature representation is key with few-shot data, and many existing models attempt to extract general information from the sample or task levels. However, the common sample-level means of feature representation limits the models generalizability to different tasks, while task-level representation may lose class characteristics due to excessive information aggregation. In this article, we synchronize the class-specific and task-shared information from the class and task levels to obtain a better representation. Structure-based contrastive learning is introduced to obtain class-specific representations by increasing the interclass distance. A hierarchical class structure is constructed by clustering semantically similar classes using the idea of granular computing. When guided by a class structure, it is more difficult to distinguish samples in different classes that have similar characteristics than those with large interclass differences. To this end, structure-guided contrastive learning is introduced to study class-specific information. A hierarchical graph neural network is established to transfer task-shared information from coarse to fine. It hierarchically infers the target sample based on all samples in the task and yields a more general representation for FSL classification. Experiments on four benchmark datasets demonstrate the advantages of our model over several state-of-the-art models.

Cingulin and its paralog paracingulin are vital components of the apical junctional complex in vertebrate epithelial and endothelial cells. They are both found in tight junctions (TJ), and paracingulin is also detectable in adherens junctions (AJ) as TJ cytoplasmic plaque proteins. Cingulin and paracingulin interact with other proteins to perform functions. They interact with cytoskeletal proteins, modulate the activity of small GTPases, such as RhoA and Rac1, and regulate gene expression. In addition, cingulin and paracingulin regulate barrier function and many pathological processes, including inflammation and tumorigenesis. In this review, we summarize the discovery and structure, expression and subcellular distribution, and molecular interactions of cingulin family proteins and discuss their role in development, physiology, and pathological processes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

The molecular mechanisms of glioblastoma (GBM) are unclear, and the prognosis is poor. Spinster homolog 2 (SPNS2) is reportedly involved in pathological processes such as immune response, vascular development, and cancer. However, the biological function and molecular role of SPNS2 in GBM are unclear. SPNS2 is aberrantly low expressed in glioma. Survival curves, risk scores, prognostic nomograms, and univariate and multifactorial Cox regression analyses showed that SPNS2 is an independent prognostic indicator significantly associated with glioma progression and prognosis. Cell function assays and in vivo xenograft transplantation were performed that downregulation of SPNS2 promoted GBM cell growth, migration, invasion, epithelial-mesenchymal transition (EMT), anti-apoptosis, drug resistance, and stemness, while overexpression of SPNS2 had the opposite effect. Meanwhile, the functional enrichment and signaling pathways of SPNS2 in the Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA), and RNA sequencing were analyzed by Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene set enrichment analysis (GSEA). The above results were related to the inhibition of the PTEN/PI3K/AKT pathway by SPNS2. In addition, we predicted that SPNS2 is closely associated with immune infiltration in the tumor microenvironment by four immune algorithms, ESTIMATE, TIMER, CIBERSORT, and QUANTISEQ. In particular, SPNS2 was negatively correlated with the infiltration of most immune cells, immunomodulators, and chemokines. Finally, single-cell sequencing analysis also revealed that SPNS2 was remarkably correlated with macrophages, and downregulation of SPNS2 promotes the expression of M2-like macrophages. This study provides new evidence that SPNS2 inhibits malignant progression, stemness, and immune infiltration of GBM cells through PTEN/PI3K/AKT pathway. SPNS2 may become a new diagnostic indicator and potential immunotherapeutic target for glioma., (© 2023 International Union of Biochemistry and Molecular Biology.)

Objectives: To investigate the value of preoperative positron emission tomography/computed tomography (PET/CT) in differentiating the invasive degree of hypometabolic lung adenocarcinoma., Methods: We retrospectively analyzed the data of patients who underwent PET/CT examination, high-resolution computed tomography, and surgical resection for low-metabolism lung adenocarcinoma in our hospital between June 2016 and December 2021. We also investigated the relationship between the preoperative PET/CT findings and the pathological subtype of hypometabolic lung adenocarcinoma., Results: A total of 128 lesions were found in 113 patients who underwent resection for lung adenocarcinoma, including 20 minimally invasive adenocarcinomas (MIA) and 108 invasive adenocarcinomas (IAC), whose preoperative PET/CT showed low metabolism. There were significant differences in the largest diameter (Dmax), lesion type, maximum standard uptake value (SUVmax), SUVindex (the ratio of SUVmax of lesion to SUVmax of contralateral normal lung paranchyma), fasting blood glucose, lobulation, spiculation, and pleura indentation between the MIA and IAC groups (p < 0.05). Multivariate logistic regression analysis showed that the Dmax (odds ratio (OR) = 1.413, 95% confidence interval (CI: 1.155-1.729, p = 0.001)) and SUVmax (OR = 12.137, 95% CI: 1.068-137.900, p = 0.044) were independent risk factors for predicting the hypometabolic IAC (p < 0.05). Receiver operating characteristic (ROC) curve analysis showed that the Dmax ≥ 10.5 mm and SUVmax ≥ 0.85 were the cut-off values for differentiating MIA from IAC, with high sensitivity (84.3% and 75.9%, respectively) and specificity (84.5% and 85.0%, respectively), the Combined Diagnosis showed higher sensitivity (91.7%) and specificity (85.0%)., Conclusions: The PET/CT findings correlated with the subtype of hypometabolic lung adenocarcinoma. The parameters Dmax and SUVmax were independent risk factors for predicting IAC, and the sensitivity of Combined Diagnosis prediction is better., (© 2023. The Author(s).)

Colorectal cancer (CRC) is one of the most common gastrointestinal malignancies. Vasorin (VASN) has been reported to be critical in tumor development and angiogenesis. However, VASN has not been reported in CRC, and its role is unclear. In this study, VASN expression is upregulated in CRC compared with the normal tissues, and VASN expression positively correlates with N stage and poor overall survival by analysis of different datasets and 32 CRC clinicopathologic samples. Overexpression of VASN significantly promotes CRC cell progression, including proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT), while knockdown of VASN inhibits CRC progression. We found that VASN was associated with the YAP/TAZ and PI3K/AKT pathways by gene set enrichment analysis (GSEA) and gene ontology (GO) analysis. Notably, western blotting, immunofluorescence staining and co-immunofluorescence (co-IP) confirmed that VASN could interact with YAP and activate the YAP/TAZ and PTEN/PI3K/AKT pathways, and knockdown of YAP reversed this effect. Importantly, our findings indicate that VASN interacts with YAP to inhibit YAP phosphorylation and stimulates CRC proliferation, migration, and invasion through activation of the YAP/TAZ-TEAD target gene CTGF and PTEN/PI3K/AKT pathways. Our results also show that knockdown of YAP reverses the cellular phenotype induced by increased VASN. In conclusion, our study reveals that VASN acts as an oncogene to stimulate tumor progression in CRC, providing new insights into the molecular mechanisms of CRC development and representing a possible novel biomarker for CRC., (© 2022 The Authors. The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)

A single device with extensive new functionality is highly attractive for the increasing demands for complex and multifunctional optoelectronics. Multi-field coupling has been drawing considerable attention because it leads to materials that can be simultaneously operated under several external stimuli ( e.g. magnetic field, electric field, electric current, light, strain, etc. ), which allows each unit to store multiple bits of information and thus enhance the memory density. In this work, we report an electro-opto-mechano-driven reversible multi-state memory device based on photocurrent in Bi 0.9 Eu 0.1 FeO 3 (BEFO)/La 0.67 Sr 0.33 MnO 3 (LSMO)/0.7Pb(Mg 1/3 Nb 2/3 )O 3 -0.3PbTiO 3 (PMN-PT) heterostructures. It is found that the short-circuit current density ( J sc ) can be switched by the variation of the potential barrier height and depletion region width at the Pt/BEFO interface modulated by light illumination, external strain, and ferroelectric polarization reversal. This work opens up pathways toward the emergence of novel device design features with dynamic control for developing high-performance electric-optical-mechanism integrated devices based on the BiFeO 3 -based heterostructures., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Exploration of rare-earth (RE)-based Kagomé lattice magnets with spin-orbital entangled j eff = 1/2 moments will provide a new platform for investigating the exotic magnetic phases. Here, we report a new family of RE 3 BWO 9 (RE = Pr,Nd,Gd-Ho) boratotungstates with magnetic RE 3+ ions arranged on Kagomé lattice and perform its structure and magnetic characterizations. These serial compounds crystallize in a hexagonal coordinated structure with space group P 6 3 (no. 173), where magnetic RE 3+ ions have distorted Kagomé lattice connections within the ab plane and stacked in an AB-type fashion along the c axis. The interlayer RE-RE separation is comparable with that of the intralayer distance, forming 3-dimensional (3D) exchange coupled magnetic framework of RE 3+ ions. The magnetic susceptibility data of RE 3 BWO 9 (RE = Pr, Nd, Gd-Ho) reveal dominant antiferromagnetic interactions between magnetic RE 3+ ions, but without visible magnetic ordering down to 2 K. The magnetization analyses for different RE 3+ ions show diverse anisotropic behaviors, making RE 3 BWO 9 as an appealing Kagomé-lattice antiferromagnet to explore exotic magnetic phases.

Three different kinds of polyurethane (PU) micelles, i.e. PEG-c-PU, PEG-g-PU and PEG-b-PU, with hydrophobic PCL core and hydrophilic PEG corona were prepared by self-assembly method. DLS studies illustrated that PEG-g-PU micelles showed pH dependent surface charge switching properties while no obvious surface charge switching activities were found for PEG-b-PU and PEG-c-PU micelles. Triclosan was loaded into PCL core by dialysis method with pretty high encapsulate content and efficiency and the payloads were released at an accelerate rate in the presence of lipase. MIC and MBC studies demonstrated an enhanced antibacterial activity of encapsulated Triclosan against planktonic bacteria than free Triclosan. CLSM images of S. aureus biofilms treated with Nile red loaded PU micelles illustrated the penetration and accumulation of PEG-g-PU micelles inside the bacterial biofilms at an acidic environment. In addition, Triclosan loaded into PEG-g-PU micelles showed more potent antibiofilm activities than that loaded into PEG-c-PEG and PEG-b-PU micelles. Therefore, the PEG-g-PU micelles can be potentially used as hydrophobic antibiotic carriers to treat bacterial infections and biofilms., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Choline phosphate (CP) containing polymers modified surfaces have been shown good resist to the adhesion of proteins while prompt the attaching of mammalian cells due to the dipole pairing between the CP groups of the polymer and the phosphorylcholine (PC) groups on the cell membrane. However, the antifouling activities of CP modified surface against microbes have not been investigated at present. In addition, CP containing polymers modified surface with different molecular architectures has not been prepared and studied. To this end, glass slides surface modified with two different 2-(meth-acryloyloxy)ethyl cholinephosphate (MCP) containing polymer (PMCP) structures, i.e. brush-like (Glass-PMCP) and bottle brush-like (Glass-PHEMA-g-PMCP) architectures, were prepared in this work by surface-initiated atom transfer radical polymerization (SI-ATRP). The surface physichemical and antifouling properties of the prepared surfaces were characterized and studied. The Glass-PMCP shows improved antifouling properties against proteins and bacteria as compared to pristine glass slides (Glass-OH) and glass slides grafted with poly(2-hydroxyethyl methacrylate) (Glass-PHEMA). Notably, a synergetic fouling resistant properties of PHEMA and PMCP is presented for Glass-PHEMA-g-PMCP, which shows superior antifouling activities over Glass-PHEMA and Glass-PMCP. Furthermore, glass slides containing PMCP, i.e. Glass-PMCP and Glas-PHEMA-g-PMCP, decrease platelet adhesion and prevent their activation significantly. Therefore, the combination of antifouling PHEMA and PMCP into one system holds potential for prevention of bacterial fouling and biomaterial-centered infections., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Polyurethane micelles with disulfide linkage located at the interface of hydrophilic shell and hydrophobic core (PU-SS-I) have been shown enhanced drug release profiles. However, the payloads could not be released completely. The occurrence of aggregation of hydrophobic cores upon shedding hydrophilic PEG coronas was considered as the reason for the incomplete release. To verify the above hypothesis and to develop a new polyurethane based micelles with dual stimuli respond properties and controllable location of pH and reduction responsive groups in the PU main chains, a tertiary amine was incorporated into the hydrophobic core PU-SS-I, which resulted polyurethane with both reduction and pH sensitive properties (PU-SS-N). Biodegradable polyurethane with only disulfide linkages located between the hydrophilic PEG segment and the hydrophobic PCL segments (PU-SS-I) and polyurethane with only pH sensitive tertiary amine at the hydrophobic core (PU-N-C) were used as comparisons. Paclitaxel (PTX) was chosen as mode hydrophobic drug to evaluate the loading and redox triggered release profiles of the PU micelles. It was demonstrated that PU-SS-N micelles disassembled instantly at the presence of 10mM GSH and at an acidic environment (pH=5.5), which resulted the nearly complete release (~90%) of the payloads within 48h, while about ~70% PTX was released from PU-SS-I and PU-SS-N micelles at neutral environment (pH=7.4) with the presence of 10mM GSH. The rapid and complete redox and pH stimuli release properties of the PU-SS-N nanocarrier will be a promising anticancer drug delivery system to ensure sufficient drug concentration to kill the cancer cells and to prevent the emergency of MDR. The in vitro cytotoxicity and cell uptake of the PTX-loaded micelles was also assessed in H460 and HepG2 cells., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In order to improve the antibacterial activities while decrease the cytotoxity of silver nanoparticles, we prepared a novel nanocomposites composed of silver nanoparticles decorated lipase-sensitive polyurethane micelles (PUM-Ag) with MPEG brush on the surface. The nanocomposite was characterized by UV-vis, TEM and DLS. UV-vis and TEM demonstrated the formation of silver nanoparticles on PU micelles and the nanoassembly remained intact without the presence of lipase. The silver nanoparticles were protected by the polymer matrix and PEG brush which show good cytocompatibility to HUVEC cells and low hemolysis. Moreover, at the presence of lipase, the polymer matrix of nanocomposites is subject to degradation and the small silver nanoparticles were released as is shown by DLS and TEM. The MIC and MBC studies showed an enhanced toxicity of the nanocomposites to both gram negative and gram positive bacteria, i.e. E. coli and S. aureus, as the result of the degradation of polymer matrix by bacterial lipase. Therefore, the nanocomposites are biocompatible to mammalian cells cells which can also lead to activated smaller silver nanoparticles release at the presence of bacteria and subsequently enhanced inhibition of bacteria growth. The satisfactory selectivity for bacteria compared to HUVEC and RBCs make PUM-Ag a promising antibacterial nanomedicine in biomedical field., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Novel two-dimensional (2D) nanostructured Ni(OH) 2 nanosheet/α-Fe 2 O 3 nanoplate composites (NFCs) were successfully synthesized by a simple two-step solvothermal method where the proportion of α-Fe 2 O 3 nanoplates was found to be controllable. These composites achieved excellent performance in aqueous electrolyte due to the synergistic effect between Ni(OH) 2 nanosheets and α-Fe 2 O 3 nanoplates, such as high specific capacitance and long-term cycle stability. The obtained NFC8 possessed a maximum mass specific capacitance of 1745.33F g -1 at a current density of 2 A g -1 , and with 84.28% retention after 3000 cycles galvanostatic charge/discharge at a high current density of 20 A g -1 . The above results show that these novel 2D nanostructured Ni(OH) 2 /α-Fe 2 O 3 composites are promising electrode materials for pseudocapacitors.

We have demonstrated a novel three-dimensional (3D) architecture of a graphene/carbon nanotube (G-CNT) hybrid synthesized at large scale within just 5 s via a simple microwave-heating method without the usage of any other conducting or expanding agent for the first time. The carbon composites obtained consist of evenly grown CNTs with an average diameter of about 15 nm on the surface of graphene nanosheets. The G-CNT hybrid exhibits enhanced electrochemical performance for both aqueous and organic supercapacitor devices. Particularly, the G-CNT electrodes demonstrate an enhanced specific capacitance of 361 F g(-1) at a current density of 1.1 A g(-1) in an aqueous electrolyte and a volumetric capacitance of 254 F cm(-3) in an organic electrolyte. They also display excellent cycle stability with nearly 91.2% of the initial capacitance retained after 10 000 charging-discharging cycles at a current density of 15 A g(-1). This demonstrates that the developed composites have potential applications in supercapacitors and other energy storage devices.