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• Comparison of cross-protection after deletion of LPS synthesis-related genes. • LPS-deficient strains induced mucosal, humoral and cellular immune responses. • The double deletion strain of rfbB and rffG provides partial protection against heterologous serotypes. Interference with the normal synthesis of LPS was shown to enhance immune responses to conserved outer membrane proteins. In the present study, we have constructed three vaccine candidates by deleting four genes (rfaL , rfbB , rffG and wzy) associated with LPS synthesis in the wild-type strain UK-1. Virulence assessment showed that after oral immunization of BALB/c mice, all mutant strains were attenuated and had significantly reduced ability to colonize host tissues compared to the wild-type strain. In addition, all three vaccine candidates induced elevated humoral, mucosal and cellular immune responses against S. Typhimurium and S. Choleraesuis OMPs compared to the PBS-treated group. Finally, immunization of mice with the rSC0136 vaccine candidate strain provided 100 % and 40 % protection against S. Typhimurium and S. Choleraesuis challenge, respectively. These results suggest that the deletion of LPS synthesis-related genes may be an effective strategy against homologous serotypes, but provides only partial protection against heterologous serotypes. [ABSTRACT FROM AUTHOR]

Depression is a common psychiatric illness affecting over 300 million people globally. Acupuncture has been reported to be a safe complementary treatment for depression. This study is aimed to investigate the efficacy and mechanism of combining acupuncture with antidepressants in treating depression compared to the sole use of antidepressants. Seventy depression patients were randomly assigned to the treatment group (n = 50) and control group (n = 20). The treatment group received acupuncture combined antidepressants treatment for 3 weeks, while the control group took antidepressants monotherapy for 3 weeks. Among the 70 patients, 40 participants (20 control; 20 treatment) were randomized for studying functional connectivity (FC) of the dorsolateral prefrontal cortex (DLPFC) measured by the functional near-infrared spectroscopy. The primary outcome was HAMD-17 and secondary outcomes were PHQ-9, and the relationships of resting-state FC (rsFC) with the depression severity. PHQ-9 and HAMD-17 scores in the treatment group were significantly lower than those in the control group at Week 3 (p = 0.01) with effect sizes of −0.4 and −0.61 respectively. The rsFC in F1, F3, AF3, AF7, FC3, FC5 (left DLPFC, 10–20 system), AF8, and F6 (right DLPFC) in the treatment group had significant temporal correlation (p < 0.05, FDR corrected) in DLPFC compared to the channels in the control group. No significant correlation was found between the changes of rsFC and depression severity. In conclusion, depressed patients receiving acupuncture combined with antidepressants have improvement of depressive symptoms and the stronger rsFC in the DLPFC compared to those using antidepressants alone. [ABSTRACT FROM AUTHOR]

Abstract Molecular composites using rigid-rod macromolecules as the reinforcement have attracted tremendous research interest. However, dispersion of rigid-rod macromolecules at molecular level in the matrix remains a great challenge. Herein, we report new epoxy (EP)-based molecular composites with sulfonated aromatic polyamides, poly(p -sulfophenylene terephthalamide) (sPPTA) and poly(benzidine-2,2′-disulfonic acid terephthamide) (PBDT), as the reinforcement, which disperse uniformly in epoxy. Covalent bonds formed by the reaction between the sulfonic acid groups of the polyamides and epoxy prevent reaction-induced phase separation during high temperature curing. The novel molecular composites exhibit extraordinarily high strength and toughness, with maximum tensile strength of sPPTA/EP and PBDT/EP (100.2 ± 4.8 MPa and 121.9 ± 12.5 MPa, respectively) increased by ∼81% and ∼120%, respectively. To the best of our knowledge, the improvement of mechanical properties surpasses those of molecular composites, nanofiller reinforced thermosets and liquid crystalline thermosets ever reported. Graphical abstract Image 1 Highlights • Molecular composites of epoxy and sulfonated aromatic polyamides. • Sulfonated aromatic polyamides disperse at molecular level in epoxy matrix. • Covalent bonding between epoxy and sulfonated aromatic polyamides prevents phase separation. • Both strength and toughness of the molecular composites are extraordinarily improved. [ABSTRACT FROM AUTHOR]

Abstract Aramid nanofibers (ANFs) are polymeric nanofibers that have been drawing tremendous attention as new nanoscale building blocks of advanced composites. Herein, we report a new strategy to rapidly synthesize functionalized ANFs (fANFs) through polymerization-induced self-assembly of poly(phenylene terephthalamide) (PPTA) using soluble sulfonated PPTA to tailor the size of fANTs, and the extraordinary reinforcing and toughening effect of fANFs on epoxy (EP) resin and multiscale carbon fiber (CF)/EP composites. With a diameter of ∼30 nm, and reactive sulfonic acid groups on the surfaces, the branched fANFs can be easily dispersed in EP and are reactive with the matrix, therefore, remarkably improve the interfacial interaction and mechanical properties (including both strength and toughness) of EP at low fANF contents. The tensile strength, Young's modulus, toughness and elongation at break of fANFs/EP nanocomposites are increased by ∼59%, ∼19%, ∼112% and ∼36%, respectively. The flexural strength, interlaminar shear strength, total energy dissipation and flexural strain at break of fANFs/CF/EP multi-scale composite are increased by ∼57%, ∼38%, ∼65% and ∼71%, respectively. To the best of our knowledge, the enhancement in the strengths is comparative with those provided by graphene oxide, and the total fracture energy and flexural strain at break are more significantly increased by fANFs than almost all of the nanofillers ever reported. [ABSTRACT FROM AUTHOR]

Reinforcement of polymers with small addition of nanofillers has been intensively investigated. It has been suggested that combination of few-layer graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs) is more effective than single nanofillers for polymer reinforcement. Herein, we report that the complexes of single-layer graphene oxide (GO) and oxidized vapor-grown carbon fibers (OVGCFs), with dimensionalities of 2 and 1, respectively, simultaneously improve the strength and toughness of epoxy and multi-scale carbon fiber reinforced composites at an extremely low content (∼0.2 wt%). The GO-OVGCF complexes are formed in water by the π-π stacking-induced self-assembly of OVGCFs and GO, and then rapidly transferred to a tertiary amine type epoxy oligomer for the preparation of epoxy and multi-scale composites. OVGCFs were observed to be wrapped by small GO sheets, which greatly improve the dispersion uniformity of OVGCFs in epoxy matrix and the filler-matrix interfacial interactions. The influences of the complexes with various GO-to-OVGCF ratios on the mechanical properties of epoxy and multi-scale composites were investigated systematically. At the optimized GO-to-OVGCF ratio, the complexes increase the mechanical properties of epoxy and multi-scale composites more significantly than previously reported individual nanofillers and the CNT-GNP hybrids. [ABSTRACT FROM AUTHOR]

Multiwalled carbon nanotubes (MWNTs) and vapor-grown carbon nanofibers (VGCNFs) were grafted with poly(styrene-co-maleic anhydride) (SMA) and poly(glycidyl methacrylate) (PGMA) by free radical polymerization, and used as the secondary reinforcing agent for multiscale carbon fiber (CF) reinforced epoxy composites. The polymer-grafted VGCNFs and MWNTs were simply suspended in ethanol and spray-coated onto the surface of CF fabrics to fabricate the multiscale composites. The structures of the polymer-grafted VGCNFs/MWNTs were characterized and their effect on the mechanical properties of multiple composites was compared. Interestingly, polymer-grafted VGCNFs with much larger diameters and lower grafting ratios are more effective than polymer-grafted MWNTs for the reinforcement; and SMA-grafted VGCNFs are more effective than PGMA-grafted VGCNFs. Addition of only 0.4 wt% (on the basis of CF fabrics) of SMA-grafted VGCNFs increases interlaminar shear strength ( ILSS) by ∼73% and flexural strength by ∼21%. The increase of ILSS exceeds those of previously reported functionalized nanotubes/nanofibers, graphene oxide or organoclay nanoplatelets as the secondary reinforcement. The high straightness and large aspect ratio of SMA-grafted VGCNFs and the strong interaction with the matrix play the key roles in the reinforcement. This new and simple method simplifies the fabrication of high-performance multiscale composites for broad applications in the future. [ABSTRACT FROM AUTHOR]

Abstract: The Double-Ceramic-Layer Thermal Barrier Coating (DCL-TBC) consists of a top ceramic layer (TC1), an inside ceramic layer (TC2), bond coat and alloy substrate. A FE numerical model had been developed to calculate the temperature of the DCL-TBC. The influence of the thermal conductivity of the TC1 layer was investigated based upon the temperature calculation results. The temperatures of the TC2 layer and the BC layer are decreased as λTC1 increases; however the temperature of the TC1 layer will be increased. These two points indicate that too large and too small values of λTC1 are all unfavorable. A reasonable range of λTC1 should exist and ensure that the temperatures in the whole DCL-TBC could be in the safe state. The reasonable range of λTC1 was investigated based on the temperature calculated and the sintering temperature of each layer. If the thickness ratio of two ceramic layers is 150μm–150μm, the reasonable range of λ is from 0.492Wm−1 K−1 to 1.654Wm−1 K−1. The reasonable range of λTC1 was investigated with considering different thicknesses of the TC1 layer. The relationship between the reasonable range of λTC1 and the thickness of TC1 (HTC1), which is shown by the safe region of λTC1–HTC1, is established. [Copyright &y& Elsevier]

Abstract: The double-ceramic-layer thermal barrier coating (DCL-TBC) consists of a top ceramic layer (TC1), an inside ceramic layer (TC2), bond coat (BC) and alloy substrate (SUB). As a parametric study, this new coating system (DCL-TBC) is studied from two different topics: the study on the heat insulation behavior of the DCL-TBC and the study on the stress state of the DCL-TBC. The works reported in the present paper is focused on the former. Based on the structure of the DCL-TBC, a FE numerical model had been developed to calculate the temperature of the DCL-TBC under the thermal loading, and three kinds of heat transport mechanisms, which are heat conduction, heat convection and heat radiation, were considered in the model. Firstly, based upon the calculation results, the relationships between the temperature of each layer in the DCL-TBC and the two structure parameters: the thickness of the TC1 layer (HTC1) and the total thickness of two ceramic layer (Htot) were mainly studied. Results had shown that the DCL-TBC with large values of HTC1 and Htot has better heat insulation ability which reduces the temperature of TC2 and BC. However, the temperature of the TC1 layer will be increased with the increase in HTC1 and Htot. These two points indicate that too large values of HTC1 (and Htot) and too small values of HTC1 (and Htot) are all unfavorable to the temperatures in the whole DCL-TBC. A reasonable range of HTC1 and Htot should exist and could ensure that the temperatures in the whole DCL-TBC could be in the safe state. Then for further study, the reasonable values of the thickness of TC1 and total thickness of two ceramic layers were investigated based on the temperature calculation results and temperature resistance of each layer, and the “temperature safe region” is obtained in the HTC1–Htot map. Based on the “temperature safe region”, it has been concluded that the total thickness of two ceramic layers should not exceed 370μm, and the thickness range of the TC1 layer can be obtained in the condition that the total thickness of two ceramic layers is a certain value. [Copyright &y& Elsevier]

Abstract: Hydrogen sulfide (H2S) is an important gaseous mediator in cellular physiology and pathology. For understanding the biological action of H2S to both healthy and disease states, it is important to develop H2S-selective sensor. Herein we report a colorimetric and fluorescent probe, which employs an NBD moiety as fluorophore, and is equipped with azide group as H2S-active unit. The probe exhibits selective and sensitive response to H2S in aqueous solution. By employing 1 μM sensor, the detection limit was evaluated to be 680 nM with a signal-to-noise ratio of 3. Confocal microscopy imaging experiments demonstrate the probe has potential as a powerful tool for the imaging of hydrogen sulfide in living cells. [Copyright &y& Elsevier]

Abstract: An iminofluorescein-Cu2+ ensemble probe was prepared for the detection of thiols in aqueous solution. In HEPES buffer, among various amino acids, only cysteine (Cys) induced fluorescence enhancement of Cu2+ ensemble. The mechanism was proposed that addition of Cys induced decomplexation of Cu2+ from weak-fluorescent ensemble, followed by hydrolytic cleavage of the resulted Schiff base to give a strongly fluorescent fluoresceinaldehyde. By fluorescence titration using 2μM iminofluorescein-Cu2+ ensemble probe, the detection limit for Cys was evaluated to be 9μM with a signal-to-noise ratio of 3. Furthermore, the confocal microscopy experiments demonstrated that this sensor was potential for the imaging of thiols in living cells. [Copyright &y& Elsevier]

Abstract: A fluorescein-based sensor bearing nitroolefin moiety for the detection of thiols was prepared. Upon addition of thiols, such as cysteine (Cys), homocysteine (Hcy) and glutathione, the solution containing sensor showed an increase of absorption intensity at 497 nm with a slight blue-shift as well as the enhancement in fluorescence intensity at 520 nm. The fluorescence enhancement and absorption change are attributed to the Michael addition of thiols to the double bond of nitroolefin moiety in sensor. The probe displays a fast response to Cys with the rate constant (k obs) of 2.3 min−1 and the detection limit to Cys was evaluated to be 0.2 μM. The confocal microscopy experiments demonstrate that this sensor is potential for the imaging of thiols in living cells. [Copyright &y& Elsevier]

Rechargeable batteries have significantly helped to effectively use renewable energy sources as well as to intensively expand the electrification of vehicles. To achieve such goals, new advanced materials are urgently required. Atomically dispersed materials (ADMs) with single-atom metals supported on substrates feature uniform metallic sites and represent the utmost utilization of atoms, demonstrating wide applications in catalysis. These structural and morphological characteristics also make ADMs attractive materials for rechargeable batteries. Herein, we highlight and summarize the recent advances in synthetic methods for ADMs by physical confinement and chemical bonding. Subsequently, we summarize the recent progress in the design of diverse ADMs for lithium metal, lithium-sulfur, sodium-sulfur, lithium-oxygen, and zinc-air batteries and unveil the corresponding roles of ADMs from atomistic perspectives. Finally, the challenges and perspectives in this field are discussed. We review how ADMs (mainly M-N-C electrode materials) have been i) synthesized; ii) characterized; iii) studied with atomistic calculations, including density functional theory (DFT); and iv) applied to Li-metal, Li–S, sodium-sulfur (Na–S), Li–O 2 , and Zn-air batteries. Challenges and perspectives in the field are also discussed. Image 1 • We reviewed the recent advances in the synthesis of ADMs, including physical confinement and chemical bonding. • We overviewed the recent progress on the use of ADMs in Li-metal, Li-S, Na-S, Li-oxygen and Zn-air batteries. • We reviewed computational works that have studied ADMs from a first-principles perspective. • Challenges and perspectives are discussed. [ABSTRACT FROM AUTHOR]

In recent years, nanomaterial reinforced composites have been extensively studied, however, research on molecular composites, i.e. composites reinforced by rigid-rod macromolecules of large aspect ratio and superior mechanical properties, is still rare. In this study, we report that when a new organosoluble rigid-rod aromatic polyamide, poly(p-aminophenylene terephthalamide) (NH 2 -PPTA), is used as a reinforcing agent of epoxy resin, it is dispersed in epoxy at molecular level at low contents but forms nanorod- or nanofiber-like aggregates in the matrices at higher contents, thereby transforming the molecular composite into a nanocomposite. The reactive amino side groups can not only improve the solubility of NH 2 -PPTA in epoxy but also participate in the curing reaction, which leads to the formation of covalent bonds between NH 2 -PPTA and the matrix. At a content as low as 0.7 wt%, NH 2 -PPTA remarkably improves the strength and toughness of epoxy resin with a tensile strength of 100.7 ± 5.3 MPa and tensile toughness of 2860 ± 316 kJ/m3, which are increased by ~74% and ~118%, respectively. The strengthening and toughening effects are comparable to those provided by graphene oxide, and are higher than by many other previously reported inorganic nanofillers. Moreover, NH 2 -PPTA also significantly improves the mechanical properties of carbon fiber (CF)/epoxy composites. Flexural strength, total fracture energy and interlayer shear strength are increased by ~9%, ~67% and~27%, respectively. This is the first report on the transition of molecular composite to nanocomposite and the effective strengthening and toughening of epoxy resin and CF reinforced composites by NH 2 -PPTA. [ABSTRACT FROM AUTHOR]

Rational strategies manipulating hydrogen-bonding and metal-coordination interactions accelerate the development of supramolecular materials with unprecedented properties, such as adaptability, self-healing, stimuli-responsiveness, reprocessability and recyclability. Herein, supramolecular interactions of thioureas were fully utilized to design new materials with adjusted mechanical performances and robust reprocessability. A series of polythioureas were facilely synthesized by the co-polycondensation of CS 2 and two diamines, which was an efficient and economical alternative to the isothiocyanate-based polymerization. Hydrogen-bonded polythiourea materials with tunable mechanical performances were achieved by adjusting the density and regularity of thiourea units in the polymer chains. Further incorporating tiny amount of metal salts (CuCl 2 , CuCl, CuBr and CuI) resulted in polythiourea materials with enhanced mechanical performances, following the trend determined by the hard-soft acid-base principle. As far as we know, this is the first report of metal-coordinated polythiourea supramolecular materials. The exploration of hard-soft acid-base principle will also provide new inspirations for designing metal-coordinated supramolecular materials. [Display omitted] • Polythiourea supramolecular materials have been developed by utilizing both hydrogen-bonding and metal-coordination interactions of thiourea units. • Adjusting the density and regularity of thiourea units in the polymer chains. • Introducing different copper salts (CuCl 2 , CuCl, CuBr and CuI) with guidance of hard-soft acid-base principle. [ABSTRACT FROM AUTHOR]

Carbon fiber reinforced composites (CFRCs) are widely used in the aviation, aerospace and automotive industries. The modification of CFRCs with nanomaterials has attracted extensive research interests in recent years. Herein, we report the preparation of novel carboxylated aramid nanofibers (cANFs) by polymerization induced self-assembly, i.e. polycondensation of para -phenylenediamine with terephthaloyl chloride in the presence of a polyamide acid as both a dispersant and surface modifier, for the modification of epoxy resin and CFRCs. cANFs effectively improve the mechanical properties of epoxy resin, and after being sprayed onto CF fabrics, greatly improve the mechanical properties of CFRCs. With the addition of only 0.42 mg/cm2 of cANFs on each CF sheets, storage modulus, flexural strength, flexural modulus and total energy dissipation are enhanced by 27 %, 51 %, 29 % and 67 %, respectively; interlaminar shear strength (ILSS) and Mode II interlayer fracture toughness (G IIC) are improved by 24 % and 74 %, respectively. cANFs can be comparable or even superior to most previously reported carbon nanomaterials in improving flexural strength and ILSS ; and exceed most previously reported electrospun nanofibrous mats in increasing G IIC. This study provides a new method for the rapid synthesis of functionalized ANFs to simultaneously increase the flexural properties and interlayer properties of CFRCs. [Display omitted] [ABSTRACT FROM AUTHOR]

Speculation and Negation Identification focuses on the extraction of speculative and negative cues and scopes. Previous work relied on complete syntactic trees or simply fed sentences into pre-trained language models, which were confronted with poor generalization within and across datasets, and the limitations of training samples. Accordingly, we build a complete pipeline framework that firstly detects cues and then extracts scopes, and propose unified Machine Reading Comprehension paradigms for both cue detection and scope resolution on several datasets. To tackle the insufficiency of training sets and produce more useful samples with appropriate amount of lexical and syntactic knowledge, we apply data augmentation integrating lexical and syntactic features for scope resolution. Experimental results show that our model achieves higher performance than baselines on several publicly accessible corpora. • Complete SNI task with cue and scope detection is fit for real-world engineering application. • Unified MRC frameworks are effective across various SNI corpora. • Lexical and syntactic data augmentation can boost scope resolution. • Our model performs well on both single-word and multi-word cues. [ABSTRACT FROM AUTHOR]

The effects of ceramic dopant species and amount on adhesive strength and thermal shock resistance behavior of nanostructured thermal barrier coatings (TBCs) were investigated in detail. Firstly, nanostructured 5 wt% La 2 O 3 +3 wt% TiO 2 +92 wt% YSZ(5La3TiYSZ), 8 wt% La 2 O 3 +92 wt% YSZ (8LaYSZ) and 8 wt% CeO 2 +92 wt% YSZ(8CeYSZ) coatings were prepared using atmospheric plasma spraying (APS) technology under the same technic parameters. Secondly, microstructure, adhesion strength and thermal shock behavior of three kinds of coatings were discussed. The results show that 5La3TiYSZ has the highest adhesion strength and the best thermal shock resistance in three kinds of coatings. The adhesion strength and thermal shock life for nanostructured TBCs heavily depend on ceramic materials. Among dopants nanostructured TiO 2 , La 2 O 3 and CeO 2 oxides, TiO 2 can take relatively good effects in YSZ and the reason are also discussed using first principles. [ABSTRACT FROM AUTHOR]

Abstract: A fluorescein-based sensor was developed for the AChE activity assay and the inhibitor screening. The sensor provided the dual assay methods for the screening of AChE activity in the presence or absence of inhibitor. The colorimetric and fluorometric assays were based on the following processes: (1) owing to the hydrolysis of acetylthiocholine in the presence of AChE, the fluorescein-based probe can rapidly induce 1,4-addition of the hydrolysis product thiocholine to α,β-unsaturated ketone in the compound 1, resulting in strong fluorescence and absorption changes; (2) in the presence of the corresponding inhibitor, the fluorescence enhancement or the absorption change would be inhibited in that the formation of thiocholine was hindered. [Copyright &y& Elsevier]

Abstract: We examined the relationship between PAH–DNA adduct levels in the placental tissue, measured by a highly sensitive 32P-postlabeling assay, and the risk of fetal neural tube defects (NTDs). We further explored the interaction between PAH–DNA adducts and placental PAHs with respect to NTD risk. Placental tissues from 80 NTD-affected pregnancies and 50 uncomplicated normal pregnancies were included in this case-control study. Levels of PAH–DNA adducts were lower in the NTD group (8.12 per 108 nucleotides) compared to controls (9.92 per 108 nucleotides). PAH–DNA adduct concentrations below the median was associated with a 3-fold increased NTD risk. Women with a low PAH–DNA adduct level in concert with a high placental PAH level resulted in a 10-fold elevated risk of having an NTD-complicated pregnancy. A low level of placental PAH–DNA adducts was associated with an increased risk of NTDs; this risk increased dramatically when a low adduct level was coupled with a high placental PAH concentration. [Copyright &y& Elsevier]