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Porcine circovirus type 2 (PCV2) often causes disease through coinfection with other bacterial pathogens, including Glaesserella parasuis (G. parasuis), which causes high morbidity and mortality, but the role played by PCV2 and bacterial and host factors contributing to this process have not been defined. Bacterial attachment is assumed to occur via specific receptor-ligand interactions between adhesins on the bacterial cell and host proteins adsorbed to the implant surface. Mass spectrometry (MS) analysis of PCV2-infected swine tracheal epithelial cells (STEC) revealed that the expression of Extracellular matrix protein (ECM) Fibronectin (Fn) increased significantly on the infected cells surface. Importantly, efficient G. parasuis serotype 4 (GPS4) adherence to STECs was imparted by interactions with Fn. Furthermore, abrogation of adherence was gained by genetic knockout of Fn, Fn and Integrin β1 antibody blocking. Fn is frequently exploited as a receptor for bacterial pathogens. To explore the GPS4 adhesin that interacts with Fn, recombinant Fn N-terminal type I and type II domains were incubated with GPS4, and the interacting proteins were pulled down for MS analysis. Here, we show that rare lipoprotein A (RlpA) directly interacts with host Fibronectin mediating GPS4 adhesion. Finally, we found that PCV2-induced Fibronectin expression and adherence of GPS4 were prevented significantly by TGF-β signaling pathway inhibitor SB431542. Our data suggest the RlpA-Fn interaction to be a potentially promising novel therapeutic target to combat PCV2 and GPS4 coinfection. Author summary: Porcine circovirus type 2 and Glaesserella parasuis (G. parasuis) are common upper respiratory tract pathogens in pigs, which co-infection causes high morbidity and mortality. However, the underlying mechanisms of host-pathogen interactions during PCV2 and GPS4 co-infection remain unclear. Here, we focused on the interaction of PCV2-infected cells and GPS4, which revealed that swine tracheal epithelial cells (STEC) infected with PCV2 exhibit the increased expression of Fn. Notably, PCV2 infection-induced Fn interacting with RlpA was shown to impart efficient adherence to GPS4. Fn and Integrin β1 antibody blocking and SB431542 counteracted PCV2 infection-induced GPS4 colonization. These studies reveal a novel receptor-ligand interaction that enhances colonization of the tracheal by GPS4 following PCV2 infection and highlights the importance of Fn-RlpA in host-pathogen interactions. In addition, RlpA was discovered for the first time as an adhesin of GPS4, which provided a new idea for the development of G. parasuis vaccines. [ABSTRACT FROM AUTHOR]

To produce high-performance dielectric capacitors for pulsed power applications, BaTiO3@(MgO–Nb2O5)–xYb2O3 (BT@MNY-x) ceramics were prepared via solid-state reaction route. The BT@MNY ceramics retained tetragonal perovskite structure without other obvious phases. Profound structural tests by Rietveld refinement of XRD patterns verified Yb3+ substituted the Ti4+ sites. In addition, after Yb3+ ions were incorporated into the lattice of barium titanate, the cubic phase of barium titanate was slightly distorted, the lattice constant of the sample gradually increased, and the tetragonality of the sample gradually decreased. With the increase of Yb2O3 content, the porosity and the diffuseness degree (γ) of the ceramics first decreased and then increased, reaching the peak values in the BT@MNY-0.5 sample. In addition, the grain size and dielectric constant of the samples decreased with the increase of Yb2O3 content. As a result, the breakdown voltage of the ceramics and performance metrics such as effective energy storage density first increased and then decreased. The calculated activation energies (Ea = 0.9–1.1 eV) closely resemble those observed for oxygen vacancy conduction activation energy in perovskite systems (around 1 eV), indicating that the conductivity in the BT@MNY ceramics is likely governed by oxygen vacancies. When x = 0.5, environmentally friendly barium titanate-based ceramics with Wrec of 0.82 J/cm3 and η of 44.34% were achieved. This work provides a theoretical basis for high energy storage barium titanate ceramics. [ABSTRACT FROM AUTHOR]

Calcium bismuth niobate (CBN) ceramic, as a core element of high-temperature piezoelectric sensors, has attracted widespread attention due to its high Curie temperature within the class of Aurivillius compounds. However, CBN usually faces two shortcomings: poor piezoelectric constant and low resistivity. In this work, CBN-based ceramics with donor–acceptor ions (W/Co) co-substituted at B-site were prepared by solid-state reaction method, and structure–property relationship of ceramics was studied in detail. Co-substitution of W/Co ions effectively improved the electrical property and hardness of CBN ceramics. CaBi2Nb 1. 9 1 (W 2 / 3 Co 1 / 3 ) 0. 0 9 O9 exhibits enhanced electrical and mechanical properties including high resistivity of ∼ 1 0 7 Ω ⋅ cm at 500°C, piezoelectric constant of ∼ 1 5. 3 pC/N and hardness value of ∼ 3. 5 7 GPa. These values are two orders of magnitude, over two times, and 1.36 times higher than those of pure CBN ceramic, respectively. This work provides a reference for exploring other bismuth-layered structural ceramics. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the impact of the Kovar glass content on the mechanical and electrical properties of Si3N4–Kovar composites sintering at air atmosphere. To achieve this, Si3N4–Kovar composites were prepared using molding technology with the Kovar glass powder ranging from 20 to 70 wt%. The phase composition, morphology, bulk density, apparent porosity, flexural strength at room temperature, dielectric constant, and dielectric loss of the composites were all examined in relation to changing the Kovar glass content. During the sintering process, the α‐quartz on the surface of Si3N4 particles acted as the crystal nucleus, inducing the crystallization of the glass at the wetting position that the Kovar glass and the surface of the Si3N4 particles. A small amount of the β‐quartz phase was crystallized at 750–850°C, followed by a large amount of the β‐quartz phase crystallizing above 900°C. Additionally, some β‐quartz phase transformed into the metastable β‐cristobalite phase that could exist below 1470°C. During the cooling process, the β‐cristobalite phase transformed into a low‐temperature α‐cristobalite phase, while the β‐quartz phase transformed into a low‐temperature α‐quartz phase. The results indicate that the Si3N4–Kovar glass composite with 60 wt% the Kovar glass content sintered at 900°C exhibits higher density (1.88 g/cm3), lower porosity (25.4%), higher flexural strength (55.34 MPa), lower dielectric constant (3.46), and lower dielectric loss (4.26 × 10−3). [ABSTRACT FROM AUTHOR]

In recent years, pressure sensors with high sensitivity and flexibility have been widely used in the fields of wearable electronics, soft robots, medical monitoring, and so on. In this paper, a through-hole structure comprising of multi-walled carbon nanotubes (MwCNTs)/carboxymethyl cellulose (CMC)/polydimethylsiloxane (PDMS) was constructed through an ice template method and then it functioned as the dielectric layer of a newly made flexible capacitive pressure sensor. The sensitivity, stability, response time, and human applicability of the sensor were fully studied. The experimental method with ice template has the advantages of environmental protection and safety. More importantly, through the regulation of chemical composition, the porous sponge can have a specific pore morphology. The experimental e results showed that the dielectric layer with a through-hole structure had been built successfully and the PDMS resin was impregnated into the through-hole structure. The MwCNTs/CMC/PDMS capacitive pressure sensor possessed a high sensitivity (~ 2.143 kPa−1) and good stability in the low-pressure range (0–1 kPa). Moreover, a low detection limit (~ 3 Pa) and fast response time (~ 250 ms) were obtained. Human applicability tests revealed that our flexible sensor could catch the response of the human body swiftly so that it exhibited bright application prospects in wearable electronics. [ABSTRACT FROM AUTHOR]

Synthesis of capsular polysaccharide (CPS), an important virulence factor of pathogenic bacteria, is modulated by the CpsBCD phosphoregulatory system in Streptococcus. Serine/threonine kinases (STKs, e.g. Stk1) can also regulate CPS synthesis, but the underlying mechanisms are unclear. Here, we identify a protein (CcpS) that is phosphorylated by Stk1 and modulates the activity of phosphatase CpsB in Streptococcus suis, thus linking Stk1 to CPS synthesis. The crystal structure of CcpS shows an intrinsically disordered region at its N-terminus, including two threonine residues that are phosphorylated by Stk1. The activity of phosphatase CpsB is inhibited when bound to non-phosphorylated CcpS. Thus, CcpS modulates the activity of phosphatase CpsB thereby altering CpsD phosphorylation, which in turn modulates the expression of the Wzx-Wzy pathway and thus CPS production. Serine/threonine kinases (STKs) regulate the synthesis of capsular polysaccharide in bacteria through unclear mechanisms. Here, Tang et al. identify a protein that is phosphorylated by an STK and modulates the activity of a phosphoregulatory system in Streptococcus suis, thus linking STKs to capsular polysaccharide synthesis. [ABSTRACT FROM AUTHOR]

The efficient 810 nm laser energy conversion of glass frit had been proven to be the key to the long‐term hermetic encapsulation of Organic Light Emitting Display (OLED). A direct laser energy conversion laser‐assisted Bi2O3‐B2O3‐ZnO‐Nd2O3 sealing glass material without extra laser absorbent such as carbon black, was designed and systematically investigated. The addition of Nd2O3, as glass modifiers with higher cationic field strength, could be conducive to enhancing the polymerization of glass network structure, manifesting that the glass‐transition temperature Tg, onset‐crystallization temperature Tc and thermal stability ΔT (ΔT = Tc‐Tg) increased, while thermal expansion coefficient CTE dropped to 9.72×10−6/°C and advantageously matched with the glass substrate (8±1×10−6/°C). More importantly, the absorption rate of BBZ‐Nd glass was more than 50 % between 800∼810 nm owing to the 4f‐4f electron transition of Nd3+ ions, and yet the reflectivity and transmittance of the wavelength at 800–810 nm were lower. As optimal compositions, the addition of 3.0 wt% Nd2O3 in Bi2O3‐B2O3‐ZnO‐Nd2O3 glass frit with higher absorption coefficients (80 %) led to instantaneous bonding encapsulation between glass substrates without interfacial cracks or pores with the 808 nm wavelength of the laser at 20 W and 2.4 mm/s. [ABSTRACT FROM AUTHOR]

GntR transcription factor of Streptococcus suis serotype 2 (SS2) is a potential substrate protein of STK, but the regulation mechanisms of GntR phosphorylation are still unclear. This study confirmed that STK phosphorylated GntR in vivo, and in vitro phosphorylation experiments showed that STK phosphorylated GntR at Ser-41. The phosphomimetic strain (GntR-S41E) had significantly reduced lethality in mice and reduced bacterial load in the blood, lung, liver, spleen, and brain of infected mice compared to wild-type (WT) SS2. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) experiments demonstrated that the promoter of nox was bound by GntR. The phosphomimetic protein GntR-S41E cannot bind to the promoter of nox, and the nox transcription levels were significantly reduced in the GntR-S41E mutant compared to WT SS2. The virulence in mice and the ability to resist oxidative stress of the GntR-S41E strain were restored by complementing transcript levels of nox. NOX is an NADH oxidase that catalyzes the oxidation of NADH to NAD+ with the reduction of oxygen to water. We found that NADH is likely accumulated under oxidative stress in the GntR-S41E strain, and higher NADH levels resulted in increased amplified ROS killing. In total, we report GntR phosphorylation could inhibit the transcription of nox, which impaired the ability of SS2 to resist oxidative stress and virulence. Author summary: Serine/threonine kinase (STK) of SS2 is involved in various important biological processes, and is crucial to bacteria pathogenicity. Our work here shows that STK can inhibit the transcription of the nox gene by phosphorylating the transcription factor GntR, which weakens the anti-oxidant capacity and virulence. SS2 lacking NOX is more likely to produce the accumulation of NADH under oxidative stimulation, which increases amplified ROS killing. [ABSTRACT FROM AUTHOR]

In this work, the pyrochlorite structure ceramic La2Zr2O7 microwave dielectric ceramics were prepared using the solid-state reaction method. The dielectric properties of La2Zr2O7 ceramics were improved by adding MgO, and the effect of the La3+ non-stoichiometric ratio on microwave dielectric properties of the La2Zr2O7–MgO ceramics was studied. Combined with XRD patterns, it was confirmed that the formation of the second phase La2MgZrO6 was inhibited with the decrease of La3+ content. And the content of La2MgZrO6 ceramic decreased with the decrease of La3+ content. The dielectric constant (εr), Quality factor (Q × f), and temperature coefficient of resonant frequency (τf) were changed correspondingly with the La3+ content. Proper reduction of La3+ content enhanced the dielectric properties of La2Zr2O7–MgO ceramics. After sintered at 1650 °C for 4 h, the La2−xZr2O7−1.5x–MgO ceramics with x = 0.16 exhibited excellent microwave dielectric properties: εr = 22.9, Q × f = 59,200 GHz and τf = − 44.6 ppm/°C. [ABSTRACT FROM AUTHOR]

Streptococcus suis serotype 2 (SS2) frequently colonizes the swine upper respiratory tract and can cause Streptococcal disease in swine with clinical manifestations of pneumonia, meningitis, and septicemia. Previously, we have shown that vimentin, a kind of intermediate filament protein, is involved in the penetration of SS2 through the tracheal epithelial barrier. The initiation of invasive disease is closely related to SS2-induced excessive local inflammation; however, the role of vimentin in airway epithelial inflammation remains unclear. Here, we show that vimentin deficient mice exhibit attenuated lung injury, diminished production of proinflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and the IL-8 homolog, keratinocyte-derived chemokine (KC), and substantially reduced neutrophils in the lungs following intranasal infection with SS2. We also found that swine tracheal epithelial cells (STEC) without vimentin show decreased transcription of IL-6, TNF-α, and IL-8. SS2 infection caused reassembly of vimentin in STEC, and pharmacological disruption of vimentin filaments prevented the transcription of those proinflammatory cytokines. Furthermore, deficiency of vimentin failed to increase the transcription of nucleotide oligomerization domain protein 2 (NOD2), which is known to interact with vimentin, and the phosphorylation of NF-κB protein p65. This study provides insights into how vimentin promotes excessive airway inflammation, thereby exacerbating airway injury and SS2-induced systemic infection. [ABSTRACT FROM AUTHOR]

The flake alumina filler is added to improve the bending strength in BaZrO3 (BZ)/BaO-MgO-ZnO-SiO2-B2O3 (BBSMZ) glass for the application of low temperature co-fired ceramics. The effects of flake alumina filler for BaZrO3/BaO-MgO-ZnO-SiO2-B2O3 on phase, microstructure, dielectric and mechanical property are studied. With the increase of flake Al2O3 content, flake Al2O3 phase appears, BaZrO3, BaZr(BO3)2, BaZn2Si2O7 phase decreases, dielectric constant decreases and dielectric loss increases. By adding flake Al2O3, the mechanical strength of the material increases. Under the same sintering conditions, the bending strength (205 MPa) of the laminated sample increased by nearly 60% compared with the same content flake alumina block sample (124 MPa), and increased by 162% compared with the sample without flake alumina (78 MPa). BZ-BBSMZ-5 wt% flake Al2O3 ceramic sintered satisfactorily at 940 °C with tanδ = 4.82*10–4 (10 GHz), εr = 11.66. The bending strength of the sample is 205 Mpa. [ABSTRACT FROM AUTHOR]

Fabricating flexible, solid, miniature and low-cost energy storage units has received growing attention as the rapid development of flexible electronic devices. Herein, we demonstrate the easy manufacturing of all-solid-state flexible supercapacitor with in-plane interdigital electrode architecture based on nickel–cobalt bimetallic sulfide NiCo2S4. With the help of a shadow mask printing technique, the NiCo2S4-based electrodes were printed on a flexible PET substrate using the home-made ink comprised of NiCo2S4, carbon nanotubes, PTFE and terpineol. Then a PVA-KOH gel electrolyte was coated and cured to complete the assembly of interdigital supercapacitor. The NiCo2S4 electrode exhibits a high specific capacitance of 1401 F/g. After 3000 cycles, the capacitance retention maintains 90%, showing a remarkable cycle stability. The assembled interdigital device delivers a high specific areal capacitance of 13.6 mF/cm2 at a current density of 0.35 mA/cm2 and an excellent energy density of 2.1 μWh/cm2 at a power density of 0.189 mW/cm2, with both long-term cycling and high rate stability. The electrochemical performance remained consistent at different bending angles (0°, 90° and 180°). This work demonstrates a simple and low-cost preparation of printable supercapacitor based on NiCo2S4 interdigital electrodes, which has a great potential to be used for flexibility, wearable and portable devices. [ABSTRACT FROM AUTHOR]

Glaesserella parasuis (G. parasuis), the primary pathogen of Glässer's disease, colonizes the upper respiratory tract and can break through the epithelial barrier of the respiratory tract, leading to lung infection. However, the underlying mechanisms for this adverse effect remain unclear. The G. parasuis serotype 5 SQ strain (HPS5-SQ) infection decreased the integrity of piglets' lung Occludin and Claudin-1. Autophagy regulates the function of the epithelial barrier and tight junction proteins (TJs) expression. We tested the hypothesis that HPS5-SQ breaking through the porcine respiratory epithelial barrier was linked to autophagy and Claudin-1 degradation. When HPS5-SQ infected swine tracheal epithelial cells (STEC), autophagosomes encapsulated, and autolysosomes degraded oxidatively stressed mitochondria covered with Claudin-1. Furthermore, we found that autophagosomes encapsulating mitochondria resulted in cell membrane Claudin-1 being unable to be replenished after degradation and damaged the respiratory tract epithelial barrier. In conclusion, G. parasuis serotype 5 breaks through the porcine respiratory epithelial barrier by inducing autophagy and interrupting cell membrane Claudin-1 replenishment, clarifying the mechanism of the G. parasuis infection and providing a new potential target for drug design and vaccine development. Author summary: G. parasuis spreads in pig herd through respiratory transmission, which colonizes the porcine respiratory tract, damages porcine respiratory epithelial paracellular, and causes porcine lung damage. G. parasuis serotype 5 infection induces autophagy in porcine respiratory epithelial cells. Autophagy is a degradation pathway for cellular proteins, organelles, and invading pathogens. It has been reported that pathogens induce autophagic degradation of epithelial tight junction proteins to disrupt epithelial barrier tight junctions. Here we show that STEC Claudin-1 covering mitochondria is enveloped and degraded by autophagy in the infection of HPS5-SQ. Our work reveals the mechanism of Claudin-1 autophagic degradation cutting off the replenishment of cell membrane Claudin-1 and providing a specific target in anti-G. parasuis spread. [ABSTRACT FROM AUTHOR]

Streptococcus suis serotype 2 (SS2) is a major zoonotic pathogen resulting in manifestations as pneumonia and septic shock. The upper respiratory tract is typically thought to be the main colonization and entry site of SS2 in pigs, but the mechanism through which it penetrates the respiratory barrier is still unclear. In this study, a mutant with low invasive potential to swine tracheal epithelial cells (STECs) was screened from the TnYLB-1 transposon insertion mutant library of SS2, and the interrupted gene was identified as autolysin (atl). Compared to wild-type (WT) SS2, Δatl mutant exhibited lower ability to penetrate the tracheal epithelial barrier in a mouse model. Purified Atl also enhanced SS2 translocation across STEC monolayers in Transwell inserts. Furthermore, Atl redistributed the tight junctions (TJs) in STECs through myosin light chain kinase (MLCK) signaling, which led to increased barrier permeability. Using mass spectrometry, co-immunoprecipitation (co-IP), pull-down, bacterial two-hybrid and saturation binding experiments, we showed that Atl binds directly to vimentin. CRISPR/Cas9-targeted deletion of vimentin in STECs (VIM KO STECs) abrogated the capacity of SS2 to translocate across the monolayers, SS2-induced phosphorylation of myosin II regulatory light chain (MLC) and MLCK transcription, indicating that vimentin is indispensable for MLCK activation. Consistently, vimentin null mice were protected from SS2 infection and exhibited reduced tracheal and lung injury. Thus, MLCK-mediated epithelial barrier opening caused by the Atl-vimentin interaction is found to be likely the key mechanism by which SS2 penetrates the tracheal epithelium. Author summary: Streptococcus suis serotype 2 (SS2), an emerging zoonotic agent, can breach the respiratory barrier and cause invasive disease in pigs. Here, we identified the novel role of autolysin Atl in penetration of the respiratory barrier by SS2 and its systemic dissemination and identified its binding partner, vimentin, a type III intermediate filament protein. Atl contributed to the MLCK-triggered redistribution of tight junctions to open the tracheal epithelial barrier. Knockout of vimentin abolished the ability of SS2 to penetrate the monolayer barrier and the activation of MLCK. Furthermore, vimentin null mice were protected from infection by intranasally administered SS2. This study is the first to demonstrate that the interaction between the GBS Bsp-like domain of Atl and vimentin promotes MLCK-mediated dysfunction of the epithelial barrier, which may provide theoretical information for prophylactic and/or therapeutic treatments against diseases caused by similar respiratory pathogens. [ABSTRACT FROM AUTHOR]

A novel category of polyphenylene oxide/high-impact polystyrene (PPO/HIPS) alloy was used as the polymer matrix (abbreviated as mPPO) and loaded with different volume fractions (0, 10, 20, 30, 40, 50 vol.%) of MgTiO3–Ca 0. 7 La 0. 2 TiO3 (abbreviated as MTCLT) ceramics to prepare composites by injection molding. Its micromorphology, density, dielectric, thermal and mechanical properties were analyzed in detail. The experimental results show that the composites possess a compact microstructure because HIPS increases the fluidity of PPO. Due to the excellent dielectric properties of both mPPO and MTCLT, the composites have an extremely low dielectric loss. The realization of the high ceramic filler fraction greatly limits the thermal expansion of the polymer chain by introducing the interphase, so that the coefficient of thermal expansion of the composite material could be as low as 21.8 ppm/ ∘ C. At the same time, the presence of ceramic particles could reinforce the mechanical property of the composites. When the ceramic filler fraction is higher than 20 vol.%, the bending strength of the composite material is around 110 MPa. When the ceramic filler fraction is 40 vol.%, the composite possesses the best comprehensive performance. The dielectric constant is 6.81, the dielectric loss is 0.00104, the thermal expansion coefficient is as low as 25.3 ppm/ ∘ C, and the bending strength is 110.4 MPa. Due to its excellent properties, this material can be a good candidate in the field of microwave communication. [ABSTRACT FROM AUTHOR]

Polyphenylene oxide (PPO)-based microwave composite substrates filled with different volume fractions (10, 20, 30, 40, 50 vol%) of MgTiO3-Ca0.7La0.2TiO3 (MTCLT) ceramics were prepared by injection-molding process. The microstructure, thermal, mechanical, and dielectric properties of the PPO/MTCLT substrates were fully studied. The results showed that PPO/MTCLT substrates with dense microstructure and uniform filler distribution were obtained when the filler fraction didn't exceed 30vol%. Further increase of the filler fraction brought about agglomeration of ceramics and weakened interfacial bonding, producing more pores in the substrates. With increasing volume fraction of ceramics, the coefficient of thermal expansion (CTE) of the substrates decreased significantly, while the bending strength increased first and then decreased, reaching a maximum at 30 vol%. Moreover, the dielectric constant of the substrates increased remarkably, while the dissipation factor decreased first and then increased. Increasing the testing frequency had little effect on the dielectric constant but increased the dissipation factor gradually. PPO/MTCLT composite substrate with filler fraction near 30 vol% exhibited the best performance and was used to fabricate a microstrip antenna. The antenna showed good performance with antenna gain over 3.54 dB and low axial ratio below 1.24 dB. The PPO/MTCLT microwave composite substrates prepared by injection-molding process exhibited good comprehensive properties, being important candidates for microwave and millimeter-wave applications. [ABSTRACT FROM AUTHOR]

The development of mid‐infrared (MIR) broadband tunable lasers urgently needs high performance laser gain materials. Transition metal (TM) ions doped glass ceramics are considered to be efficient MIR broadband laser gain media. However, it is difficult to achieve gain because of the large scattering loss and low luminescence efficiency. In this paper, GeS2–Sb2S3–CsI–PbI2 chalcohalide glass ceramics containing CsPbI3 perovskite nanocrystals are fabricated by the melt‐quenching method and subsequent heating treatment. The crystallization behavior of CsPbI3 nanophase and MIR luminescence properties of Ni2+ dopant are systematically investigated. Evidently, spherical CsPbI3 perovskite nanocrystals are precipitated and uniformly distributed in the glassy matrix, which can reduce the light scattering and make the chalcohalide glass ceramics have a high transparency. Moreover, an ultra‐broadband MIR emission in the range of 2.5–5.5 μm is observed for the first time, to our best knowledge, from Ni2+‐doped chalcohalide glass ceramics containing CsPbI3 perovskite nanocrystals. The newly developed Ni2+‐doped chalcohaldie glass ceramics could be promising gain media for MIR broadband tunable lasers. [ABSTRACT FROM AUTHOR]

Glaesserella parasuis (G. parasuis) is a commensal bacterium in the upper respiratory tract of pigs that can also cause the swine Glässer disease, which induces an intensive inflammatory response and results in significant economic losses to the swine industry worldwide. G. parasuis can cause disease through infection of the respiratory tract, resulting in systemic infection, but the mechanism is largely unknown. Recently we showed that Glaesserella parasuis serotype 4 (GPS4) increased swine tracheal epithelial barrier permeability, resulting in easier bacterial translocation. Tight junction proteins (TJ) play a crucial role in maintaining the integrity and impermeability of the epithelial barrier. GPS4 decreased the expression of the TJ ZO-1 and occludin in swine tracheal epithelial cells (STEC). Furthermore, the proinflammatory cytokines IL-6, IL-8 and TNF-α were significantly upregulated in GPS4-infected STEC, and both the MAPK and NF-κB signaling pathways were activated and contributed to the expression of TNF-α. We demonstrate that the production of proinflammatory cytokines, especially TNF-α, during GPS4 infection was involved in barrier dysfunction. Additionally, animal challenge experiments confirmed that GPS4 infection downregulated TJ in the lungs of piglets and induced a severe inflammatory response. In general, G. parasuis infection downregulated the expression of TJ and induced massive secretion of proinflammatory cytokines, resulting in epithelial barrier disruption and favoring bacterial infection. This study allowed us to better understand the mechanism by which G. parasuis crosses the respiratory tract of pigs. [ABSTRACT FROM AUTHOR]

MgNb2O6 ceramics doping with different amounts of LiF (0–0.4 wt%) were prepared via a solid-state reaction method. The sintering behavior, phase evolution, microstructure, and microwave dielectric properties of the LiF-doped MgNb2O6 ceramics were fully investigated. The results showed that with the increase of LiF from 0 to 0.4 wt%, the sintering temperature of MgNb2O6 ceramic decreased significantly from 1300 to 1100 °C, as the sintering activation energy of the MgNb2O6 ceramic was reduced. A second-phase LiNbO3 was identified when the amount of LiF reached 0.2 wt%, leading to an obvious deterioration to the Qf value of MgNb2O6 ceramic. MgNb2O6 ceramic doped with 0.1 wt% LiF exhibited excellent microwave dielectric properties with εr = 20.7, Qf = 90,300 GHz, and τf = − 71.3 ppm/°C, after sintering at 1175 °C for 4 h. [ABSTRACT FROM AUTHOR]

The combination of low dielectric constant (εr) and a high-quality factor (Q × f) in MgO ceramics makes them attractive for 5G applications. However, the large negative temperature coefficient of resonance frequency (τf) impedes these applications. In this paper, the composite ceramics of MgO–xMTiO3 (M = Ca, Sr; x = 0, 2.5, 5, 7.5, 10 wt%) with the addition of 4 mol% LiF as a sintering aid were fabricated by the traditional solid-state reaction method. The coexistence both MgO and MT phases can be observed in XRD and SEM in the 4 mol% LiF–MgO–wt%MTiO3 systems under the high-temperature sintering process. With the addition of MT, the grain size of MgO decreased, the εr value improved with τf value gradually increasing from negative to positive value. Optimized microwave dielectric properties were achieved for 4 mol%LiF–MgO–10wt%SrTiO3 ceramics sintered at 1300 °C for 6 h, yielding εr = 11.2, Q × f = 46, 815 GHz, and τf = + 3.51 ppm/°C. Based on it, a prototype of microstrip patch antenna was designed and fabricated with a center frequency at 5.64 GHz for 5G–Sub6GHz communication applications. [ABSTRACT FROM AUTHOR]

In order to improve the thermal properties of polytetrafluoroethylene (PTFE) as a high-frequency microwave dielectric substrate, PTFE/glass fiber (GF) composites filled with Si3N4 were prepared by the method of combining cold pressing and normal pressure sintering. The effects of content of Si3N4 on microstructure, thermal and dielectric properties of the PTFE/GF composites were studied by scanning electron microscope, laser thermal conductivity analyzer, thermal dilatometer and impedance analyzer, respectively. The results showed that silane coupling agent (KH550) could improve the dispersibility of the Si3N4 particles in PTFE to some extent and Si3N4 fillers could significantly improve the thermal properties of PTFE. Compared with pure PTFE, the coefficient of thermal expansion of PTFE/GF composite filled with 45wt% Si3N4 decreased from 109 to 27 ppm/°C and the thermal conductivity increased nearly twice. The dielectric constant of PTFE/GF composites grew with the content of Si3N4 and had good frequency stability. Although the dielectric loss of the composites deteriorated with the addition of Si3N4, it was significantly decreased with increasing frequency, indicating that there is a potential application of Si3N4 filled PTFE/GF composites in the field of high-frequency dielectric substrate. [ABSTRACT FROM AUTHOR]

This study analyzed the difference between biofilm and planktonic Brucella abortus using metabolomics and proteomics. Brucella abortus was cultured in different media to induce Brucella abortus biofilm formation and planktonic cells, followed by metabolomics and proteomics analyses for these two samples. Significant differential metabolites were identified, followed by KEGG pathway analysis. Differentially expressed proteins were identified, followed by subcellular localization, GO annotation, and KEGG pathway enrichment. Additionally, a correlation analysis of metabolomics and proteomics was performed. Metabolomics analysis showed 7682 positive and 4433 negative metabolites, including 188 positive and 117 negative significant differential metabolites. These differential metabolites were enriched in fatty acid/unsaturated fatty acid biosynthesis and linoleic acid metabolism. Proteomics analysis revealed 1759 proteins, including 486 differentially expressed proteins, which were enriched in various metabolic and degradation-related pathways. Subcellular localization showed that 74.3% of the differential proteins were cytoplasmic proteins. Correlation analysis showed that 1-palmitoyl-2-oleoyl-phosphatidylglycerol had the most significant correlations with proteins, followed by cytosine. Both metabolites correlated with the protein Q57EI7 (RbsB-1, ribose ABC transporter). One common pathway, fatty acid biosynthesis, was identified by both proteomics and metabolomics analyses that involved the metabolites, oleic acid, and protein Q57DK3 (biotin carboxylase). There were metabolomic and proteomic differences between Brucella abortus biofilm and planktonic cells, and these results provide novel insights into the biofilm-forming process of Brucella abortus. [ABSTRACT FROM AUTHOR]

The 40Bi2O3-30B2O3-(30−x)ZnO-xSrO (x=0–15mol%, BBZSr) glass system was prepared by the conventional melt quenching method. The effect of SrO addition on structure, thermal properties, chemical stability and sealing performance of BBZSr glass were investigated thoroughly. The experimental results show that the total proportions of [BO3] group and [BO4] group decrease and the vibrations of [BiO3] group and [BiO6] group become weaker with the increase of SrO addition content, suggesting the glass network structure is strengthened owing to the SrO addition. Hence, both the thermal and chemical stability were significantly improved as the SrO content was increased. When the SrO content increased from 0 to 15mol%, the glass transition temperature and softening temperature slightly increased from 380 to 388 °C and from 392.7 to 402.2 °C, respectively, meanwhile the coefficient of thermal expansion also increased from 10.49×10−6 to 11.16× 10−6/°C (30–300 °C). The BBZSr glass with 15mol% SrO exhibited excellent comprehensive properties with low glass transition temperature(384.9 °C), low softening temperature(400.3 °C), high coefficient of thermal expansion (11.14×10−6 C, 30–300 °C), good thermal and chemical stability. Besides, the glass had the good wetting behavior and sealing performance for Al-50%Si alloy. [ABSTRACT FROM AUTHOR]

Gehlenite‐type Ca2Al2SiO7 ceramics were prepared by the conventional solid‐state reaction. Two anomalies were found in the plot of dielectric constant vs temperature, which were associated with space charge polarization. Pure phase crystal structure and no phase transition were observed in the temperature‐dependent X‐ray diffraction (XRD) patterns and Raman spectra from room temperature (RT) to 900°C. There was relevant relation between Q × f and τƒ with the stretching vibrations of Ca‐O bond and O‐Ca‐O bending in CaO8 polyhedron. Excellent microwave dielectric properties (εr = 8.86, Q × f = 22 457 GHz, and τf = −51.06 ppm/°C) were obtained for Ca2Al2SiO7 sintered at 1440°C in air, which had the potential application to use in microwave and millimeter‐wave devices such as capacitors and substrates. [ABSTRACT FROM AUTHOR]

Porcine circovirus type 2 (PCV2) is considered as the primary pathogen of porcine circovirus-associated disease (PCVAD), which results in significant economic losses worldwide. Clinically, PCV2 often causes disease through coinfection with other bacterial pathogens, including Streptococcus suis (S. suis), and especially the highly prevalent S. suis serotype 2 (SS2). The present study determined that continuous PCV2 infection in piglets down-regulates tight junction proteins (TJ) ZO-1 and occludin in the lungs. Swine tracheal epithelial cells (STEC) were used to explore the mechanisms and consequences of disruption of TJ, and an in vitro tracheal epithelial barrier model was established. Our results show that PCV2 infection in STEC decreases the expression levels of ZO-1 and occludin and increases the permeability of the tracheal epithelial barrier, resulting in easier translocation of SS2. Moreover, Western blot analysis indicates that PCV2 infection activates the JNK/MAPK pathway. The disruption of TJ in SETC and increased permeability of the epithelial barrier induced by PCV2 could be alleviated by inhibition of JNK phosphorylation, which indicates that the JNK/MAPK pathway regulates the expression of ZO-1 and occludin during PCV2 infection. This study allows us to better understand the mechanisms of PCV2 coinfection with bacterial pathogens and provides new insight into controlling the occurrence of PCVAD. [ABSTRACT FROM AUTHOR]

0.8MgTiO3 − 0.2(Ca0.7La0.2)TiO3 (MTCLT) ceramic fillers with excellent microwave dielectric properties have been incorporated in a novel polysilylaryl-enyne (PSAE) resin with low dielectric loss to prepare PSAE/MTCLT composite. A unique process free of organic solvent has been employed to fabricate the composite. The results showed that highly dense and homogeneous microstructure was observed in all the composites with different filler volume fractions. With the increase in MTCLT volume fraction, the dielectric constant of the composite increased significantly from 2.8 to 10.0, while the dielectric loss decreased from 0.0056 to 0.0030 at 10 GHz. The coefficient of thermal expansion (CTE) of the composite could be reduced to less than 20 ppm/°C when 40 V% MTCLT ceramic was loaded which achieved a good match with copper foil. TGA and DMA results showed that the composite possessed excellent temperature resistance with the temperature at 5% mass loss (Td5)> 850 °C and glass transition temperature (Tg) > 400 °C at N2 atmosphere. The novel thermosetting PSAE/MTCLT composite reported in this work has good application prospects in high-power integrated circuits and some high-temperature-resistant environments. [ABSTRACT FROM AUTHOR]

Glasses with the composition 50SiO2 · 20TiO2 · 15BaO · 7.5SrO · 7.5CaO doped with the varied content of CeO2 were prepared by conventional melt quenching technique. The effect of CeO2 on the structure of glasses was investigated by X-ray photoelectron spectroscopy and Raman spectroscopy. The density, thermal stability, dielectric properties and acid resistance of glasses were studied by Archimedes method, differential thermal scanning analysis and X-ray diffraction, dielectric measuring as well as the powder method. The results showed that the coordination of Ti, which existed in glasses as [TiO4], did not change. An increase in the content of non-bridging oxygen atoms and a corresponding decrease in the content of bridging oxygens correlated. The depolymerization of the glass network was attributed to an increase in the number of Si–O–Ti bonds and the change of the Qn distribution. With an increase in the CeO2 content, the thermal stability and acid resistance of glass first increased and then decreased, and the dielectric constant and dielectric loss of glass decreased first and then increased. [ABSTRACT FROM AUTHOR]

Streptococcus equi subsp. zooepidemicus (SEZ) is a zoonotic pathogen capable of causing meningitis in humans. The mechanisms that enable pathogens to traverse the blood-brain barrier (BBB) are incompletely understood. Here, we investigated the role of a newly identified Fic domain-containing protein, BifA, in SEZ virulence. BifA was required for SEZ to cross the BBB and to cause meningitis in mice. BifA also enhanced SEZ translocation across human Brain Microvascular Endothelial Cell (hBMEC) monolayers. Purified BifA or its Fic domain-containing C-terminus alone were able to enter into hBMECs, leading to disruption of monolayer barrier integrity. A SILAC-based proteomic screen revealed that BifA binds moesin. BifA’s Fic domain was required for its binding to this regulator of host cell cytoskeletal processes. BifA treatment of hBMECs led to moesin phosphorylation and downstream RhoA activation. Inhibition of moesin activation or moesin depletion in hBMEC monolayers abrogated BifA-mediated increases in barrier permeability and SEZ’s capacity to translocate across monolayers. Thus, BifA activation of moesin appears to constitute a key mechanism by which SEZ disrupts endothelial monolayer integrity to penetrate the BBB. [ABSTRACT FROM AUTHOR]

A temperature stable high-Q Li2Zn0.95Sr0.05Ti3O8 microwave dielectric ceramic is fabricated by conventional solid-state reaction route and the phase composition, microstructures and microwave dielectric properties are investigated in this paper. The bulk density and FESEM results indicate that this ceramic can be well-sintered at 1075 °C for 4 h. Since the difficulty in Sr2+ ions diffused into the Li2ZnTi3O8 crystal lattice to form solid solutions owing to the large radii difference between Sr2+ (1.44Å) and Zn2+ (0.74Å), there are three phases including the main phase Li2ZnTi3O8 and the second phase SrTiO3 and unknown phase according to the XRD and element-distribution mapping results. The formation of second phase is advantageous to improve the relative permittivity (εr) and temperature coefficient of resonant frequency (τf), but degrades the quality factor (Q × f) slightly. The Li2Zn0.95Sr0.05Ti3O8 ceramic sintered at 1075 °C/4 h displays a temperature stable high-Q properties: εr = 26.6, Q × f= 62300 GHz, and τf = 0.27 ppm/°C. [ABSTRACT FROM AUTHOR]

A novel glass-free MoO3-based dielectric ceramic of Li2Ni2(MoO4)3 was prepared by the conventional solid-state route. The phase compositions, microstructures and microwave dielectric properties were investigated. The XRD data analysis shown that Li2Ni2(MoO4)3 belongs to an orthorhmbic lyonsite-type structure with Pmcn (62) space group during the sintering temperature range from 650 to 725 °C. The Li2Ni2(MoO4)3 ceramic could be well densification at 700 °C for 2 h with 96.8% relative density and exhibited excellent microwave dielectric properties: εr = 9.2, Q × f = 41,064 GHz, τf = − 68.86 ppm/°C. Moreover, the Li2Ni2(MoO4)3 ceramic shown excellent compatible with Ag electrode, which makes it a promising candidate for advanced substrate materials in low temperature co-fired ceramic applications. [ABSTRACT FROM AUTHOR]

A novel low temperature co-fired ceramic (LTCC) material was fabricated by zinc titanate (ZnTiO3) ceramics doped with B2O3-BaO-SiO2-ZnO-Li2O (BBSZL) glass. The influences of BBSZL glass on wetting behavior, sintering activation energy, phase composition, microstructure and microwave dielectric properties were investigated. The experimental results show that the sintering temperature of ZnTiO3 ceramics can be reduced from 1 100 to 925 °C, meanwhile the sintering activation energy is decreased from 465.32 to 390.54 kJ·mol-1 by BBSZL glass aid, respectively. Moreover, BBSZL glass can inhibit the high Q×f ZnTiO3 phase decompose into the low Q×f value Zn2TiO4 phase, which is propitious to obtain high Q×f value LTCC material. The ZnTiO3-BBSZL composite sintered at 925 °C displays the excellent microwave dielectric properties with εr of 21.8, Q×f value of 42000 GHz, and τf of -75 ppm·°C-1. [ABSTRACT FROM AUTHOR]

PTFE matrix loaded with different volume fractions of MgTiO3 ceramic powder with particle sizes of around 5 μm and 15 μm (abbreviated as MT-5 and MT-15, respectively) was prepared. The microstructure, microwave dielectric properties and thermal properties of the composites were studied by scanning electron microscope, vector network analyzer and thermal dilatometer. The results show that PTFE/MT-15 composite exhibits higher relative density and better dielectric properties than the PTFE/MT-5 composite, since the former with coarse particles possesses lower surface energy to weaken the particle agglomeration effect. Even at 40% filler volume fraction, the ultra-low dielectric loss of PTFE/MT-15 composite can be maintained in the order of 10− 4 at 10 GHz. Different models are used to predict the dielectric constant of the composites. Among which, the effective medium theory shows the least deviation from the experimental results. PTFE matrix filled with 40V% MT-15 ceramic powder shows excellent microwave dielectric properties: εr = 5.5, tanδ = 2.7 × 10− 4 (at 10 GHz), which may be a promising material in electronic packaging field. [ABSTRACT FROM AUTHOR]

Background: Swine streptococcosis has caused great economic loss in the swine industry, and the major pathogen responsible for this disease is Streptococcus Suis serotype 2 (SS2). Disease resistance breeding is a fundamental way of resolving this problem. With the development of GWAS and transcriptomic microarray technology, we now have powerful research tools to identify SS2 resistance genes. Results: In this research, we generated an F2 generation of SS2 resistant C57BL/6 and SS2 susceptive A/J mice. With the F2 generation of these two mice strains and GWAS analysis, we identified 286 significant mouse genome SNPs sites associated with the SS2 resistance trait. Gene expression profiles for C57BL/6 and A/J were analyzed under SS2 infection pressure by microarray. In total, 251 differentially expressed genes were identified between these two mouse strains during SS2 infection. After combining the GWAS and gene expression profile data, we located two genes that were significantly associated with SS2 resistance, which were the UBA domain containing 1 gene (Ubac1) and Epsin 1 gene (Epn 1). GO classification and over-representation analysis revealed nine up-regulated related to immune function, which could potentially be involved in the C57BL/6 SS2 resistance trait. Conclusion: This is the first study to use both SNP chip and gene express profile chip for SS2 resistance gene identification in mouse, and these results will contribute to swine SS2 resistance breeding. [ABSTRACT FROM AUTHOR]

A low temperature co-fired ceramic (LTCC) material of Li2ZnTi3O8-TiO2 (L2ZT3-TiO2) doped with BaO-B2O3-ZnO (BBZ) glass were prepared by conventional solid-state method. The effects of BBZ glass on the phase composition, microstructure, and microwave dielectric properties were investigated. The results indicated that BBZ glass as a sintering aid could effectively reduce the sintering temperature of L2ZT3-TiO2 ceramic below 950 °C. The XRD patterns indicated that L2ZT3-TiO2 ceramic consisted of Li2ZnTi3O8 and TiO2 phases. BBZ glass addition did not change the phase composition. In addition, the SEM demonstrated that BBZ glass could significantly improve the grain growth and densification. The sintering mechanism was analyzed through the wetting behavior and the activation energy (Ea). When added 2.5 wt% BBZ glass, the average activation energy reduced from 492.38 ± 139.03 to 370.69 ± 20.98 kJ/mol, which indicated that the BBZ glass not only effective lowered the sintering temperature but also promoted the sintering process. The L2ZT3-TiO2 ceramic with 2.5 wt% BBZ sintered at 925 °C for 4 h had excellent microwave dielectric properties of εr = 26.3, Q × f = 36,554 GHz and τf = − 4.16 ppm/°C. In addition, the good chemical compatibility of this material with Ag electrode could make it as a potential candidate for LTCC technology. [ABSTRACT FROM AUTHOR]

A temperature stable low temperature co-fired ceramic (LTCC) was fabricated by the powder mixture of Li2ZnTi3O8 ceramic, TiO2 τf-tailoring dopant and B2O3-La2O3-MgO-TiO2 (BLMT) glass sintering aid, and the sintering behavior, activation energy, phase composition, microstructure and microwave dielectric properties of the composite were investigated in the composition range (wt%) of 5 BLMT-(95-x) Li2ZnTi3O8−X TiO2 (x = 0, 1, 2, 3, 4 and 5). The sintering behavior results showed that all composites could be well sintered at 910 °C for 2 h through liquid-phase sintering. The activation energy of Li2ZnTi3O8 ceramic was calculated to be 520.9 ± 40.46 kJ/mol, while 5BLMT-93Li2ZnTi3O8-2TiO2 (in wt%) composite was reduced to 330.98 ± 47.34 kJ/mol. The XRD results showed that Li2ZnTi3O8 and TiO2 phase stably existed in all sample and a new phase LaBO3 was crystallized from BLMT glass during sintering process. As x increases, the rutile TiO2 phase increased in composite, which could adjust the temperature coefficient of resonant frequency (τf) to near-zero owing to the opposite τf value to other phases. And simultaneously dielectric constant (εr) demonstrated gradually increase, whereas the quality factor (Q × f) decreased gradually. The composite with x = 2 had an optimal microwave dielectric properties with εr = 25.3, Q × f = 32,800 GHz, and τf = − 0.54 ppm/°C. The corresponding fitting equations of εr, Q × f and τf on the x value were obtained by the Origin software, indicating that the dielectric properties of the composite could be precisely controlled by varying the content of TiO2. In addition, the good chemical compatibility of this material with Ag electrode made it as a potential candidate for LTCC technology. [ABSTRACT FROM AUTHOR]

Abstract: Four MgO‐Ta2O5 ceramics with the MgO/Ta2O5 mole ratio x = 1, 2, 3, and 4 were prepared by traditional solid‐state reaction method, and the influence of x on the phase composition, microstructure, and dielectric properties (the dielectric constant εr, the temperature coefficient of resonant frequency τf and the quality factor Qf) of the materials was investigated using XRD, SEM, etc. The results indicated that the ceramics were composed of two crystalline phases MgTa2O6 and Mg4Ta2O9 in the composition range studied, and that the dielectric properties ln ε, 1/Qf, and τf changed proportionally to the fraction of main crystal phases, which meet perfectly with the mixing model proposed in this study. It is obvious that the proportion of the two crystal phases could be precisely controlled by x, and thereby, the dielectric properties can be conveniently and precisely tailored. Our research provided a new microwave dielectric ceramic with the composition of 2MgO‐Ta2O5, which has an ultrahigh Qf value (211 000 GHz), low dielectric constant εr (19.9), and near zero temperature coefficient of resonant frequency τf (8 ppm/°C). [ABSTRACT FROM AUTHOR]

A low temperature co-fired ceramic (LTCC) was fabricated at 910 °C /2 h from the powder mixture of Li2Zn3Ti4O12, TiO2 and a B2O3-La2O3-MgO-TiO2 glass (BLMT), and the influence of TiO2 on microstructure and dielectric properties of the composite was investigated in the composition range (wt%) of 20BLMT-(80 − x)Li2Zn3Ti4O12-xTiO2 (x = 0, 2.5, 5, 7.5, 9 and 10). The results showed that all samples consisted of Li2Zn3Ti4O12, TiO2, LaBO3 and LaMgB5O10 phase. And LaBO3, LaMgB5O10 and a small amounts of TiO2 were crystallized from BLMT glass during sintering process. As x increases, dielectric constant and temperature coefficient of resonance frequency of the composites demonstrated gradually increase, whereas the quality factor of the sample of x = 0 wt% was about 41,500 GHz and the ones maintained stable at a high level of 49,000-51,000 GHz for other samples. The composite with x = 9 wt% had an optimal microwave dielectric properties with the dielectric constant of 20.2, quality factor of 50,000 GHz and temperature coefficient of resonant frequency of − 0.33 ppm/°C. [ABSTRACT FROM AUTHOR]

The (1 − x)Li2TiO3-xLi2Mg3TiO6 (x = 0.1, 0.15, 0.2, 0.3, 0.4, 0.5) ceramics system was fabricated by solid-state synthesis. Test results of X-ray diffraction and electron diffraction spectrum show that all ceramic samples only contain Li2TO3 and Li2Mg3TiO6 phase. Scanning electron microscope shows that pores were found in crystal grain due to Li volatilization in high temperature (> 1000 °C). With the rise proportion of Li2Mg3TiO6 in ceramics, dielectric constant (ɛr) decreases from 19.55 to 14.53, quality factor (Q×f) increases from 102,800 to 126,000 GHz and temperature coefficient (τf) decreases from + 15.9 to − 30.08 ppm/°C. High performance microwave dielectric properties of ɛr = 18.5, Q×f = 108,000 GHz, τf = 4.2 ppm/°C were obtained at 1390 °C for 0.85Li2TiO3-0.15Li2Mg3TiO6 ceramics. To suppress Li volatilization, LiF, a low temperature melting addition, was added to 0.85Li2TiO3-0.15Li2Mg3TiO6 ceramics. LiF effective lowers sintering temperature from 1390 to 1175 °C due to LiF liquid-phase sintering and restricts Li evaporation, and a well-developed grain morphology and excellent dielectric properties (ɛr = 18.5, Q×f = 87,000 GHz, τf = − 18 ppm/°C) was obtained which hold promise in 4G tele-communication applications. [ABSTRACT FROM AUTHOR]

The effects of BO additive on the phase composition and microwave dielectric properties of MgTaO ceramic were investigated by solid state reaction method. The results showed that the BO additive can lower sintering temperatures of MgTaO ceramics from 1425 °C to below 1325 °C. The XRD patterns exhibited that chemical reactions happened between MgTaO and BO forming two new phases MgTaO and MgTaO (BO) during sintering in the materials. As BO additive increased from 0 to 5 wt%, MgTaO and MgTaO (BO) phases also gradually increased. At the same time, the relative permittivity (ε) increased from 11.67 to 12.57, whereas the quality factor (Qf) decreased from 280,000 GHz to 170,000 GHz, and the temperature coefficient of resonant frequency (τ) remained unchanged. The changes of the dielectric properties with the BO additive content were correlated with the phase evolutions of the material during sintering. Typically, the MgTaO-1 wt% BO ceramic sintered at 1325 °C for 4 h acquired the best dielectric properties: ε = 12.15,Qf = 260000 GHz,and τ = − 64 ppm/°C. [ABSTRACT FROM AUTHOR]

Low temperature co-fired ceramics composite is fabricated by mixing BO-LaO-MgO-TiO (BLMT) glass matrix with BaTiO ceramic filler and the influence of the filler on sintering behavior, phase composition, microstructure and dielectric properties of the composite is investigated. The results show that the densification of composites can be achieved at 860 °C for 20 min by three-stage reactive liquid assisted sintering process, consisting of glass redistribution and local grains rearrangement, viscous flow, and solid state sintering and closure of pores. The XRD patterns exhibit that the main phase of all samples is LaBO phase formed from the crystallization of BLMT glass and the secondary phases have changed due to chemical reaction between BLMT glass and BaTiO forming two new phases BaTi(BO) and TiO during sintering. Meanwhile, the microstructure results indicate that the reaction helps to eliminate the closed pores in composites. As the filler is increased, the dielectric constant and quality factor firstly increases and then decreases, while the temperature coefficient of resonant frequency increases. Typically, the 30 wt% BaTiO-filled BLMT glass composite sintered at 860 °C for 20 min displays dielectric properties of εε = 20.49, Q × f = 24000 GHz and ττ = +145 ppm/°C. [ABSTRACT FROM AUTHOR]

A low temperature co-fired ceramic (LTCC) material has been fabricated by mixing BaTiO ceramic powder with a BaO-BO-ZnO (BBZ) glass and sintering the mixture at 925 °C/2 h. The influence of the BBZ glass on sintering behavior, phase evolution, microstructure and microwave dielectric properties of the BaTiO-based LTCC material has been investigated. The results show that the BBZ glass can significantly lower the sintering temperature of the BaTiO ceramics from 1350 °C to below 950 °C. The XRD patterns exhibit that remarkable chemical reactions happen between BaTiO and the BBZ glass during sintering, forming two new phases BaTi(BO) and BaTiO in the material. As BBZ glass is increased from 5 to 30 wt%, BaTi(BO) phase gradually dominates the material and BaTiO decreases and almost disappears at the end. At the same time, the dielectric constant decreases from 33 to 25, the temperature coefficient of resonant frequency decreases from +25.44 to −3.19 ppm/°C, and the quality factor firstly increases and then decreases with the peak value of 29500 GHz. The changes of the dielectric properties with the BBZ glass content are correlated with the phase evolution of the material during sintering. Typically, the BaTiO-based ceramics with 25 wt% BBZ glass sintered at 925 °C for 2 h displays excellent comprehensive properties with a maximum density of 4.33 g/cm, the dielectric constant of 27.08, quality factor of 29,500 GHz and temperature coefficient of resonant frequency of +3.5 ppm/°C. In addition, the good chemical compatibility of this material with Ag electrode makes it a potential candidate for LTCC technology. [ABSTRACT FROM AUTHOR]

Porcine epidemic diarrhea virus (PEDV) causes significant loss to the swine industry. The emergence of novel PEDV strains in recent years has decreased the effectiveness of PEDV vaccines. We have developed a live recombinant vaccine, a swinepox virus vector that expresses a truncated S protein (rSPV-St) from a recent PEDV strain, SQ2014, and evaluated its immunogenicity and effectiveness in a swine model. Vaccination of swine with rSPV-St elicited a robust antibody response specific for the homologous PEDV SQ2014. Serum IgA titers in rSPV-St-vaccinated animals were significantly higher than in those immunized with inactivated vaccines. The effectiveness of antibodies induced by the rSPV-St vaccine in protection against PEDV was tested in a passive-transfer model in which piglets were challenged with the homologous virus SQ2014 and the heterologous strain CV777. When challenged with the homologous virus, sera from rSPV-St vaccination provided complete protection. However, sera from rSPV-St vaccination did not provide any protection against the heterologous virus challenge. Amino acid sequence differences in the S proteins of the two viruses were identified within neutralizing epitopes, which might have contributed to the divergent clinical results. Our data suggest that rSPV-St is potentially an effective vaccine against infection with emerging PEDV strains. [ABSTRACT FROM AUTHOR]

Novel microwave dielectric ceramic YZnAlSiO were synthesized by solid-state route. The crystal structure of synthesized samples was characterized by X-ray diffraction and refined with Rietveld method. Microstructure and microwave dielectric properties of YZnAlSiO ceramics were investigated using Scanning Electron Microscopy and Hakki-Coleman method. X-ray data display that major phase of YZnAlSiO is isostructural to YAlO with a cubic garnet structure and space group of Ia-3d, which is composed of (Al/Si)O tetrahedron, (Zn/Al)O octahedron and YO dodecahedron, besides minor YSiO secondary phase. The distribution of grain sizes is closer to Gauss distribution. Bulk density of samples has a similar variation curve with Q* f of samples. YZnAlSiO ceramics exhibit excellent microwave dielectric properties: ε = 10.2, Q* f = 37938.2 (@9.47 GHz), τ = −31.7 ppm/°C at sintering temperature of 1500 °C. Our results indicate YZnAlSiO could be a potential material for millimeter wave communication systems as microwave substrates. [ABSTRACT FROM AUTHOR]

Microstructure and microwave dielectric properties of (1-x)LiMgTiO-xCaSrTiO (x = 0.03, 0.06, 0.08, 0.09, 0.12) ceramics prepared by the conventional solid state route have been investigated. XRD and SEM-EDS analysis confirmed that ceramics contain LiMgTiO and CaSrTiO phases. The microwave properties exhibited a significant dependence on the sintering temperature and CaSrTiO content. With increasing addition of CaSrTiO, the dielectric constant $$({\varepsilon _r})$$ increased from 14.3 to 17.4 when samples sintered at 1410 °C for 4 h; the quality factor (Q × f) decreased from 133,905 to 101,000 GHz, and the temperature coefficient of resonant frequency ( $${\tau _f}$$ ) significantly increased from −39 to 6.35 ppm/°C when samples sintered at 1370 °C for 4 h. Sample with 0.91LiMgTiO-0.09CaSrTiO sintered at 1370 °C for 4 h possess excellent microwave properties with $${\varepsilon _r}$$ of 16.4, a Q × f of 113,000 GHz and $${\tau _f}$$ of −3.65 ppm/°C. It is proposed as low-loss and low-cost dielectric materials for microwave and millimeter wave application. [ABSTRACT FROM AUTHOR]

The 1:2 ordering is known to play an important role in quality factor of complex perovskite microwave dielectric ceramics, while the relationship of 1:1 ordering on quality factor is little known. In this work, The 1:1 ordering in Sr(ZnNb)O were studied by X-ray diffraction and Raman spectroscopy. Results show the increased in the quality factor as the sintering time increase is caused mainly by the decrease of the 1:1 ordering degree. [ABSTRACT FROM AUTHOR]

The (1− x)Mg2Al4Si5O18- xTiO2 |(1− x) MAS- xT| (0 ≤ x ≤ 0.35) cordierite ceramics are fabricated by solid-state reaction method for obtaining near-zero temperature coefficient of resonant frequency (τf). The XRD and SEM results show that (1− x) MAS- xT (0 ≤ x ≤ 0.10) ceramics exhibit single cordierite solid solution, whereas as 0.15 ≤ x ≤ 0.35, present composite phases of Mg2Al4Si5O18 solution and TiO2. Rietveld refinements of XRD data suggest that the [(Si4Al2)O18] hexagonal shape in cordierite structure happens to alternate change from nonsymmetrical hexagonal rings to almost centrosymmetrical equilateral rings as x increases to 0.10 comparing to that of x = 0. As Ti4+ ions squeeze into the [(Si4Al2)O18] rings structure, the orientation and shapes of the rings begin to rotate and expand from initial state of [1-20] ( x = 0) to near [210] direction ( x = 0.10), and then continue to expand toward close to [110] direction ( x = 0.25). Due to centrosymmetry adjustment of [(Si4Al2)O18] hexagonal rings and of other microstructure factors improvement, the (1− x) MAS- xT ( x = 0.10) cordierite solution achieves optimum quality factor Qf: εr = 6.3, Qf = 55 400 GHz (17.6 GHz), τf = −21 ppm/°C. The (1− x) MAS- xT ( x = 0.25) composites obtain a near-zero temperature coefficient of resonance frequency: εr = 6.8, Qf = 37 800 GHz (18.4 GHz), τf = −0.2 ppm/°C. [ABSTRACT FROM AUTHOR]

Swine influenza (SI) is an acute respiratory infectious disease of swine caused by swine influenza virus (SIV). SIV is not only an important respiratory pathogen in pigs but also a potent threat to human health. Here, we report the construction of a recombinant swinepox virus (rSPV/H3-2A-H1) co-expressing hemagglutinin (HA1) of SIV subtypes H1N1 and H3N2. Immune responses and protection efficacy of the rSPV/H3-2A-H1 were evaluated in guinea pigs. Inoculation of rSPV/H3-2A-H1 yielded neutralizing antibodies against SIV H1N1 and H3N2. The IFN-γ and IL-4 concentrations in the supernatant of lymphocytes stimulated with purified SIV HA1 antigen were significantly higher ( P < 0.01) than those of the control groups. Complete protection of guinea pigs against SIV H1N1 or H3N2 challenge was observed. No SIV shedding was detected from guinea pigs vaccinated with rSPV/H3-2A-H1 after challenge. Most importantly, the guinea pigs immunized with rSPV/H3-2A-H1 did not show gross and micrographic lung lesions. However, the control guinea pigs experienced distinct gross and micrographic lung lesions at 7 days post-challenge. Our data suggest that the recombinant swinepox virus encoding HA1 of SIV H1N1 and H3N2 might serve as a promising candidate vaccine for protection against SIV H1N1 and H3N2 infections. [ABSTRACT FROM AUTHOR]