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Various proteins with antibacterial, anticoagulant, and anti-inflammatory properties have been identified in the buccal glands of jawless blood-sucking vertebrate lampreys. However, studies on endogenous peptides in the buccal gland of lampreys are limited. In this study, 4528 endogenous peptides were identified from 1224 precursor proteins using peptidomics and screened for bioactivity in the buccal glands of the lamprey, Lethenteron camtschaticum. We synthesized four candidate bioactive peptides (VSLNLPYSVVRGEQFVVQA, DIPVPEVPILE, VVQLPPVVLGTFG, and VPPPPLVLPPASVK), calculated their secondary structures, and validated their bioactivity. The results showed that the peptide VSLNLPYSVVRGEQFVVQA possessed anti-inflammatory activity, which significantly increased the expression of anti-inflammatory factors and decreased the expression of inflammatory factors in THP-1 cells. The peptide VVQLPPVVLGTFG showed antibacterial activity against some gram-positive bacteria. The peptide VSLNLPYSVVRGEQFVQA possessed good ACE inhibitory activity at low concentrations, but no dose-related correlation was observed. Our study revealed that the buccal glands of the jawless vertebrate lamprey are a source of multiple bioactive peptides, which will provide new insights into the blood-sucking mechanism of lamprey.

The underlying structural origin of magnetic properties is still elusive in Fe-based amorphous alloys. In this study, distinctive soft magnetic properties were developed in Fe76Si9B10P5 amorphous ribbons through systematic design of annealing process. Combining with synchrotron radiation, high-resolution transmission electron microscopy and first principle ab initio molecular dynamic simulation, it is found that the atomic structural evolution both in short range order and medium range order is responsible for the magnetic softness at proper annealing temperature. In short range, formation of separated and densely coordinated Fe-metalloid clusters is instigated to adapt energy minimization, resulting in strengthening of ferromagnetic exchange interaction locally. In medium range, a homogeneous exchange-coupling from the uniformly strong and weak ferromagnetic regions is generated, which significantly weakens magnetic heterogeneity and leads to the excellent magnetic softness. Our findings may provide an effective/promising pathway to modulate the magnetic properties for Fe-based amorphous alloys, and give a comprehensive and quantitative understanding of the structure-properties relationship in amorphous materials.

Two new noncentrosymmetric superconductors SnVSe2 and PbVSe2 with topological nontrivial states are predicted via a systematic first-principles study.

We carry out a global structure search for the Nb–Pb system based on the evolutionary algorithm and density functional theory. Based on the dynamical and mechanical stability analyses, we unveiled five new Nb–Pb binary phases.

Tryptophan is mainly degraded through kynurenine pathway (KP) in vertebrates which is closely related to the nerve and depression, while the studies on immunity is still limited. This study aims to explore the functions of tryptophan in the innate immunity of primitive vertebrate lamprey. MTT (3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide) assay showed that tryptophan had no obvious effect on cell viability. Tryptophan was transported into leukocytes and degraded via the KP after tryptophan supplement. Tryptophan treatment (T1x and T2x) failed to alter the total antioxidant capacity regardless of stimulation and exposure time. Real-time quantitative PCR and western blotting results revealed that tryptophan was not only able to reduce the expression of pro-inflammatory factors Lj-TNF-α, Lj-IL1β and Lj-NF-κB, but also to upregulate the expression of anti-inflammatory factor Lj-TGF-β independent of stimulation and time. In addition, tryptophan can exert immune tolerance function by inhibiting TLR-MyD88 and promoting (Indoleamine 2, 3-Dioxygenase) IDO-kynurenine-AHR (aryl hydrocarbon receptor) pathways. This study provides a new understanding for tryptophan-kynurenine metabolism and mechanism of immune tolerance function in primitive vertebrate lamprey.

Lampreys are blood-sucking vampires in the marine. From a survival perspective, it is expected that lamprey buccal gland exhibits a repository of pharmacologically active components to modulate the host’s homeostasis, inflammatory and immune responses. Several proteins have been found to function as anticoagulants, ion channel blockers, and immune suppressors in lampreys, while small metabolites have never been explored in detail. In this study, by analyzing the metabolic profiles of 14 different lamprey tissues, we have identified two groups of blood-sucking-associated metabolites, i.e., kynurenine pathway metabolites and prostaglandins, in the buccal gland and they can be injected into the host fish to ensure a steady and sustained blood flow to the feeding site. These findings demonstrate the complex nature of lamprey buccal gland and highlight the diversity in the mechanisms utilized for blood-sucking in lampreys. In addition, a lamprey spatial metabolomics database (https://www.lampreydb.com) was constructed to assist studies using lampreys as model animal. The database contains detailed qualitative, quantitative, and spatial distribution information of each detected metabolite, and users can easily query and check their metabolites of interest, and/or identify unknown peaks using the database.Significance StatementLampreys are one of the two surviving jawless vertebrate groups that hold the key to our understanding of the early vertebrate evolution, adaptive immune origin, and developmental neurobiology. Here, we applied a spatial metabolomics approach to study the lamprey-host interaction. Two groups of metabolites, i.e., kynurenine pathway metabolites and prostaglandins, were found in the lamprey buccal gland, which modulate the host’s homeostasis, inflammatory and immune responses. The establishment of the first tissue-wide spatial lamprey metabolomics database in this study facilitate future studies in biochemistry, clinical chemistry, natural product discovery, medicine, and metabolomics using lampreys as a model animal.

L10-FeNi hard magnetic alloy with coercivity reaching 861 Oe was synthesized through annealing Fe42Ni41.3Si8B4P4Cu0.7 amorphous alloy, and the L10-FeNi formation mechanism has been studied. It is found the L10-FeNi in annealed samples at 400 °C mainly originated from the residual amorphous phase during the second stage of crystallization which could take place over 60 °C lower than the measured onset temperature of the second stage with a 5 °C/min heating rate. Annealing at 400 °C after fully crystallization still caused a slight increase of coercivity, which was probably contributed by the limited transformation from other high temperature crystalline phases towards L10 phase, or the removal of B from L10 lattice and improvement of the ordering quality of L10 phase due to the reduced temperature from 520 °C to 400 °C. The first stage of crystallization has hardly direct contribution to L10-FeNi formation. Ab initio simulations show that the addition of Si or Co in L10-FeNi has the effect of enhancing the thermal stability of L10 phase without seriously deteriorating its magnetic hardness. The non-monotonic feature of direction dependent coercivity in ribbon segments resulted from the combination of domain wall pinning and demagnetization effects. The approaches of synthesizing L10-FeNi magnets by adding Si or Co and decreasing the onset crystallization temperature have been discussed in detail.

The contributing effects of Si inclusion on the fabrication and performance of the Fe-based amorphous/nano-crystalline alloys were extensively studied with the first principle molecular dynamics simulation method. Si is found to have complicated impact on the formation of amorphous structure as it is structurally preferred to crystallize with Fe but energetically beneficial to stabilize the amorphous when reaching high concentration. The inclusion of Si is also found to cause the increase of the crystallization temperature and give rise to better controllability of the nano-crystallization process for better magnetic softness. Magnetically, Si can always reduce the saturation magnetization in the Fe-based alloy but also can indirectly help decreasing the overall coercivity of the Fe-based nano-crystalline alloy.

It is extremely rare for the coexistence of two spin glass transitions in single phase materials. In the present paper, the structure and magnetic properties of Tb2Ni0.8Mn0.2Si3 were investigated. For comparison, the corresponding experimental results of Tb2NiSi3 compound were also provided. In the temperature dependence of dc susceptibility measurements, there are two anomaly transitions for both Tb2Ni0.8Mn0.2Si3 and Tb2NiSi3. Further studies on the frequency dependence of ac susceptibility show a new spin-glass transition at 14 K in Tb2Ni0.8Mn0.2Si3, except for the spin-glass transition at 8 K inheriting from Tb2NiSi3. This new spin-glass transition in Tb2Ni0.8Mn0.2Si3 is absent in Tb2NiSi3. It takes place below the long-range magnetic ordered phase transition and shows cluster spin glass behaviors, and it is attributed to the introduction of Mn ions into the intermetallic compound.

SiC fiber-reinforced Ti-21Al-29Nb matrix composites with either C and C/Mo duplex coatings were prepared by the foil-fiber-foil (FFF) method, in order to comparatively study the effects of C/Mo duplex coatings on the interface and mechanical properties of the composites. The longitudinal tensile strength of the as-prepared composites was measured at room temperature. In order to study the interfacial thermal stability and microstructure evolution characteristics of the composites, vacuum thermal exposures of the composites were carried out at 800, 900 or 940 °C for different durations. The interfacial microstructures of the as-prepared and thermally-exposed composites were investigated by means of scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS). The results indicate that the C/Mo duplex coating does not only have better thermal stability, but also can further slow down the interfacial reaction of the composites in comparison with the C single coating. The diffusion of a small amount of Mo atoms made the matrix close to the interface have better plasticity, so the tensile strength of the composites can be further improved. The interface of the composite with the C/Mo duplex coating was nearly intact after the 940 °C/50 h thermal exposure while that of the composite with the C single coating was not intact, as the C/Mo duplex coating can better relax the thermal residual stresses than the C single coating.

The magnetic influence of silicon, boron, phosphorous, niobium, as well as Cu in Fe-rich amorphous was studied through ab initio molecular dynamics simulations. The small concentration of metalloids with large electronegativity is beneficial to the saturation magnetization of Fe-rich amorphous alloys, but may reduce the magnetization by p–d orbital hybridization with a large amount of inclusion. On the other hand, owing to their low electronegativity, early transition metals may bring excess electrons to the alloys system and reduce the effect of Fe electron absorption by boron or phosphorous; therefore, the inclusion of them will significantly reduce the magnetization of the alloy. The minor inclusion of Cu slightly exhibits negatively charged in Fe-rich amorphous alloys, which indicates that the transition metals with low electron losing tendency are acceptable in the alloy to maintain excellent soft magnetic properties with high magnetization.

The potential electrical applications for soft magnetic materials have spurred the research of Fe-based nano-crystalline alloys.

Fe76Si9B10P5 metallic glass is an excellent material for its good glass-forming ability and soft magnetic property. However, a large gap still exists toward a better theoretical understanding, which explains their excellent properties that have been experimentally observed. In this paper, we perform molecular dynamics simulation to study the atomic scale structure and clarify the origin for the good magnetic property. The results suggest that the glassy alloy consists of B/P centered dense spaces and sparsely spread Si-rich regions. Fe atoms in the dense area are positively charged and possess larger magnetic moment up to 2.6 μB, which is larger than that in pure α-Fe. The negatively charged B and P atoms were possible reasons for the charge transfer and enhancement of magnetic moment.

The epitaxial growth of the buffer layer on a textured metal substrate has a significant influence on the performance of coated conductors, which provides the potential to support a high current for electric utility and high magnetic field applications at 77 K. In this paper, we have fabricated the CeO2 buffer layer on YSZ (yttria-stabilized zirconia) (00l) single crystal substrates by the chemical solution deposition (CSD) method in different annealing atmospheres. The results show that both the thermal decomposition behavior of the precursor solution and the annealing atmosphere have an important effect on the epitaxial growth process of the CeO2 buffer layer. The large oxygen partial pressure in annealing atmosphere is to the disadvantage of the epitaxial growth of CeO2 (00l) crystal face with high energy. Moreover, the epitaxial growth of the CeO2 (00l) crystal plane goes against a decrease in the surface roughness of the CeO2 film. Therefore, it can be considered that the orientation growth of the CeO2 buffer layer and its surface morphology evolution may be related to the thermal decomposition behavior of precursor solution and the change of oxygen vacancies concentration.

YBCO films were fabricated by using a modified precursor solution, which was prepared by mixing yttrium trifluoroacetate, barium trifluoroacetate, and a fluorine-free copper precursor. Crack-free films have been obtained in a rapid pyrolysis process. The texture, microstructure and superconducting properties of films were characterized by x-ray diffraction, scanning electron microscopy, and the inductive method, respectively. The effect of the heating rate on the phase formation, texture and critical properties (Jc) of YBCO films was investigated. The texture and critical current density varied significantly with the heating rate. Moreover, the Jc of 1.7 MA/cm2 was obtained for YBCO films prepared at the heating rate of 3 K/min.

We have studied the texture transfer process of buffer layers prepared by chemical solution deposition (CSD) methods on YSZ (00l) single crystal substrates and biaxial textured Ni–W substrates. The structure, texture, and surface morphology of the buffer layers were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM). Our results show that the degree of texture and the surface morphology of the buffer layers vary with the changes of the substrate and the lattice mismatch of the top buffer layers with La2Zr2O7 (LZO) after crystallization in argon–hydrogen atmosphere. Moreover, the growth mode of multi-layer films and the type of the lattice strain have strong influence on the formation and the transfer of the bi-axial texture in multi-layer buffer architecture. It suggests that there exists a possible connection between the strain relaxation and the texture transfer in buffer layer fabricated by CSD methods. Information on the texture transfer of buffer layer is important for optimizing the buffer layer architecture in coated conductors.

The Sm-doping YBCO films, Y1−xSmxBa2Cu3Oy and Y1SmxBa2−xCu3Oy (x=0.1, 0.3), were fabricated on LAO (00l) single-crystal substrates by TFA-MOD process in order to improve the superconducting properties of YBCO films. The XRD analyses indicated that these samples have a strong c-axis texture, but the secondary phase of BaCuO2 are found from Y1SmxBa2−xCu3Oy films with Sm3+ substitution on Ba2+ sites. High quality surface, better in-plane and out-of-plane texture of the Sm-doping films have been obtained compared with that of the undoped YBCO film. The Y0.9Sm0.1Ba2Cu3Oy films showed the highest value of Tc and Jc in self-field. Superconducting properties of all Sm-doping films are better than those of the pure film. These results strongly suggest that Sm-substitution on Y or Ba sites of YBCO phase is a powerful method to efficiently improve Jc and introduce artificial pinning centers in YBCO films.

We have evaluated the effect of annealing in oxygen atmosphere on the structure, texture and phase transformation of LZO films deposited on YSZ (yttria-stabilized zirconia) (0 0 l ) single crystal substrates and textured NiW substrates by metal-organic deposition (MOD) method. The results show that the structure stability of the LZO films is heavily dependent on the oxygen partial pressure in annealing process. Then we have in details studied the behavior of oxygen diffusion in three kinds of buffer layer architectures on NiW substrates by varying the temperature, oxygen partial pressure and dwelling time in the annealing process. The oxygen diffusion within buffer layers leads to the oxidation of substrate, and even the texture and structure of buffer layers are destroyed with the increase of the thickness of the oxides layer related to NiW substrate. It reveals that the relative volume of oxides related to NiW substrate increases exponentially with the annealing temperature, and increases linearly with the annealing time at logarithmic scale. The relative intensity of texture peaks of buffer layers decreases and even disappears with the increase of the oxygen partial pressure in annealing process because of the acceleration of the oxidation reaction of substrate. The influence of annealing temperature, oxygen partial pressure and dwelling time on the oxygen diffusion is related to the intrinsic oxygen diffusion coefficient of buffer layers materials. Compared with the increase of oxygen partial pressure, the elongation of dwelling time shows a less effect on the oxidation rate of NiW substrate and a weak destruction of the texture of buffer layers. Except choosing the oxide materials with small oxygen diffusion coefficient as buffer layers in coated conductors, the degree of oxidation about NiW substrate could be greatly controlled and it would result in the less destruction of texture and structure of buffer layers by adjusting the annealing temperature, oxygen partial pressure and dwelling time in the process of YBCO deposition.

GdBa2Cu3O7−x (GdBCO) films have been deposited on LaAlO3 (LAO) (0 0 l) single crystal substrates by trifluoroacetate metal organic deposition (TFA-MOD) method. The effects of oxygen partial pressure and firing temperature on microstructure and critical properties of GdBCO films were discussed. The phase formation, texture and microstructure of films were characterized by X-ray diffraction and scanning electron microscopy. The oxygen partial pressure was considered to play a great role for formation of impurity phase and a-axis oriented grains. The degree of c-axis orientation was also influenced by the firing temperature. The highly c-axis oriented GdBCO film obtained at 815 °C under an oxygen partial pressure of 100 ppm has a high performance critical current density Jc (77 K, self field) = 1.8 MA/cm2.

A large amount of research efforts have been focused on the development of Fe-based amorphous alloys, a kind of soft magnetic materials that is promising in the potential application of motors, transformers and choke coils due to their excellent soft magnetic property. The extraordinarily low coercivity is caused by the disordered structure and the lack of micro-scale anisotropy. Generally, the inclusion of the minor alloying elements necessary for the formation of the amorphous structure can interfere with the Fe-Fe ferromagnetic exchange and reduce the maximum magnetization [1], which is a disadvantage for the efficiency and minimization of the produced devices. On the other hand, it is reported that some common alloying metalloids, such as B and P, can promote the Fe atoms in amorphous alloys into high spin state with larger magnetic moment [2]. The present study is to clarify and optimize the magnetic effect of the alloying elements in Fe-rich amorphous alloys. In this research work, ab initio molecular dynamics simulations were performed for Fe 85 Si 2 B 8 P- 4 Cu 1 , Fe 76 Si 9 B 10 P 5 and Fe 73.5 Si 13.5 B 9 Nb 3 Cu 1 amorphous alloys. Considering the electric charge transfer, electron structure as well as the cluster formation, it is clarified that minor inclusion of B and P can effectively absorb electrons from Fe atoms, making the radii of 3d orbitals of Fe decrease towards optimum ferromagnetic exchange between Fe-Fe atoms. However, with increasing B/P content, the replacement of Fe-Fe bonds by Fe-metalloids bonds makes severe magnetically inert p-d hybridization which reduces the spin polarization of 3d electrons as well as the magnetic moments [3]. Therefore, B and P have complicated magnetic effect in Fe-based amorphous alloys, which appears to promote magnetization with low concentration, but reduces it at larger concentration. Besides, it was found that Si shows no beneficial effect on increasing the magnetization of the amorphous alloys due to the hybridization between Si 3p and Fe 3d orbitals, although experimental data indicate that Si is good for amorphous formation or crystallization controllability [4].

In this article, the atomic behaviors of Nb and P in Fe-based amorphous alloys during nano-crystallization process were studied by the combination of ab initio molecular dynamics simulations and experimental measurements. The inclusion of Nb is found to be tightly bonded with B, resulting in the formation of diffusion barrier that could prevent the over-growth of α-(Fe, Si) grains and the promotion of larger amount of α-(Fe, Si) participation. The P inclusion could delay the diffusion of the metalloids that have to be expelled from the α-(Fe, Si) crystallization region so that the grain growth could be reduced with fast but practically achievable heating rates. The combined addition of P and Nb in high Fe content amorphous alloys failed in exhibiting the potential of good magnetic softness with slow heating (10 K/min) annealing at various temperatures. The sample with optimum crystallization process with confined grain size was annealed at 653 K, with the grain size of 31 nm and a coercivity of ∼120 A/m, ...

In the work reported in this paper, ab initio molecular dynamics simulation was performed on Fe85Si2B9P4 amorphous alloy. Preferred atomic environment of the elements was analyzed with Voronoi polyhedrons. It showed that B and P atoms prefer less neighbors compared with Fe and Si, making them structurally incompatible with Fe rich structure and repulsive to the formation of α-Fe. However, due to the low bonding energy of B and P caused by low coordination number, the diffusion rates of them were considerably large, resulting in the requirement of fast annealing for achieving optimum nano-crystallization for its soft magnetic property. The simulation work also indicates that diffusion rate in amorphous alloy is largely determined by bonding energy rather than atomic size.

Iron-based amorphous alloys have attracted a growing interest due to their potential in the application of magnetic coil production. However, the magnetization of this kind of material is usually low due to the lack of long range ordering and high alloying element content. In this paper, an Fe76B19P5 amorphous alloy was simulated with ab initio molecular dynamics based on a previous simulation work on an Fe76Si9B10P5 amorphous alloy exhibiting that electron absorbers such as B and P can help enhance the magnetization of nearby Fe atoms. The present simulation results show that replacing Si with B can destabilize the amorphous structure, making it easier to crystallize, but no separate α-Fe participation can be observed in experiments during annealing due to its high B/P content. The results also show an increase in saturation magnetization by 8% can be expected due to the intensified electron transfer from Fe to B/P, and the glass forming ability decreases correspondingly. The idea of enhancing electron transfer can be applied to the development of other Fe-based amorphous alloys for the purpose of larger saturation magnetization.