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NiAl alloy sheet was successfully prepared using current-assisted sintering, thus verifying the possibility of preparing a NiAl thin-wall component by current-assisted sintering and foil/foil reaction synthesis. Ni/Al laminated sheets were obtained by annealing at 550 °C at 5 MPa for 0.5 h; uniform NiAl alloy sheets were fabricated by annealing at 1150 °C at 15 MPa for 20 min. The experimental results showed that current-assisted sintering significantly reduced the reaction temperature and reaction time. Microstructural characterization revealed that the inter-diffusion ability of Al atoms is considerably weaker than that of Ni atoms. Molecular dynamics simulation confirmed these experimental results and showed that this difference becomes significant under the action of an electric field. The mechanism of synthesis of Ni/Al laminated sheets using current sintering is mainly determined by the diffusion behavior of Ni atoms. [ABSTRACT FROM AUTHOR]

Cold seeps are pervasive along the continental margin worldwide, and are recognized as hotspots for elemental cycling pathway on Earth. In this study, analyses of pore water geochemical compositions of one ∼400 cm piston core (S3) and the application of a mass balance model are conducted to assess methane-associated biogeochemical reactions and uncover the relationship of methane in shallow sediment with gas hydrate reservoir at the Makran accretionary wedge off Pakistan. The results revealed that approximately 77% of sulfate is consumed by the predominant biogeochemical process of anaerobic oxidation of methane. However, the estimated sulfate-methane interface depth is ∼400 cm below sea floor with the methane diffusive flux of 0.039 mol/(m2·a), suggesting the activity of methane seepage. Based on the δ13CDIC mass balance model combined with the contribution proportion of different dissolved inorganic carbon sources, this study calculated the δ13C of the exogenous methane to be −57.9‰, indicating that the exogenous methane may be a mixture source, including thermogenic and biogenic methane. The study of pore water geochemistry at Makran accretionary wedge off Pakistan may have considerable implications for understanding the specific details on the dynamics of methane in cold seeps and provide important evidence for the potential occurrence of subsurface gas hydrate in this area. [ABSTRACT FROM AUTHOR]

Our previous studies have shown that miR-125b-5p was highly expressed and significantly upregulated during abdominal fat deposition in chickens. However, the role of miR-125b in the regulation of adipogenesis is not clear in chickens. Therefore, we evaluated the effects of miR-125b-5p on preadipocyte proliferation and differentiation and the interaction between miR-125b-5p and the acyl-CoA synthetase bubblegum family member 2 (ACSBG2) gene in adipogenesis in chicken abdominal adipose tissue. Here, transfection tests of miR-125b-5p mimic/inhibitor were performed in preadipocytes, and the effects of miR-125b-5p on preadipocytes proliferation and differentiation were analyzed. The target site of miR-125b-5p in the 3′UTR (untranslated region) of ACSBG2 were verified by a luciferase reporter assay. Our results showed that miR-125b-5p overexpression inhibited proliferation and reduced the number of cells in S phase and G2/M phase in preadipocytes; conversely, miR-125b-5p inhibition promoted the proliferation and increased the number of cells in S phase and G2/M phase. In adipocytes after induction, miR-125b-5p overexpression led to a notable increase in the accumulation of lipid droplets as well as in the concentration of triglycerides, while miR-125b-5p inhibition had the opposite effect. Furthermore, miR-125b-5p could directly bind to the 3'UTR of ACSBG2, and its overexpression could significantly repress the mRNA and protein expression of ACSBG2. These results indicate that miR-125b-5p can inhibit preadipocyte proliferation and can promote preadipocyte differentiation to affect adipogenesis in chicken abdominal adipose tissues, at least partially by downregulating ACSBG2. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii is a protozoan parasite capable of infecting a large number of warm-blooded animals and causes serious health complications in immunocompromised patients. T. gondii infection of the feline small intestine is critical for the completion of the life cycle and transmission of T. gondii. Protein acetylation is an important posttranslational modification, which plays roles in the regulation of various cellular processes. Therefore, understanding of how T. gondii reprograms the protein acetylation status of feline definitive host can help to thwart the production and spread of T. gondii. Here, we used affinity enrichment and high-resolution liquid chromatography with tandem mass spectrometry to profile the alterations of the acetylome in cat small intestine 10 days after infection by T. gondii Prugniuad (Pru) strain. Our analysis showed that T. gondii induced significant changes in the acetylation of proteins in the cat intestine. We identified 2606 unique lysine acetylation sites in 1357 acetylated proteins. The levels of 334 acetylated peptides were downregulated, while the levels of 82 acetylated peptides were increased in the infected small intestine. The proteins with differentially acetylated peptides were particularly enriched in the bioenergetics-related processes, such as tricarboxylic acid cycle, oxidative phosphorylation, and oxidation-reduction. These results provide the first baseline of the global acetylome of feline small intestine following T. gondii infection and should facilitate further analysis of the role of acetylated protein in the pathogenesis of T. gondii infection in its definitive host. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii secretes a group of rhoptry-secreted kinases (ROPs), which play significant roles in promoting intracellular infection. T. gondii rhoptry organelle protein 17 (ROP17) is one of these important effector proteins. However, its role in modulating host cell response during infection remains poorly understood. Here, we reveal that ROP17 (genotype I) induces significant changes in the expression genes and transcription factors of host cells. HEK293T cells were transfected with PCMV-N-HA-ROP17 plasmid or empty control PCMV-N-HA plasmid. Transcriptomic analysis revealed 3138 differentially expressed genes (DEGs) in PCMV-N-HA-ROP17-transfected HEK293T cells, including 1456 upregulated, 1682 downregulated DEGs. Also, 715 of the DEGs were transcription factors (TFs), including 423 downregulated TFs and 292 upregulated TFs. Most differentially expressed TFs, whether belong to signal transduction, cancer-related pathways or immune-related pathways, were downregulated in ROP17-expressing cells. ROP17 also decreased alternative splicing events in host cells, presumably via alteration of the expression of genes involved in the alternative splicing pathway. Taken together, our findings suggest a novel strategy whereby T. gondii ROP17 manipulates various cellular processes, including immune response through reprogramming host gene expression to promote its own colonization and survival in the infected host cells. [ABSTRACT FROM AUTHOR]

Porous alginate-based hydrogel beads (porous ABH) have been prepared through a facile and sustainable template-assisted method using nano-calcium carbonate and nano-CaCO3 as pore-directing agent for the efficient capture of methylene blue (MB). The materials were characterized by various techniques. The sorption capacities of ABH towards MB were compared with pure sodium alginate (ABH-1:0) in batch and fixed-bed column adsorption studies. The obtained adsorbent (ABH-1:3) has a higher BET surface area and a smaller average pore diameter. The maximum adsorption capacity of ABH-1:3 obtained from Langmuir model was as high as 1,426.0mg g-1. The kinetics strictly followed pseudo-second order rate equation and the adsorption reaction was effectively facilitated, approximately 50minutes to achieve adsorption equilibrium, which was significantly shorter than that of ABH-1:0. The thermodynamic parameters revealed that the adsorption was spontaneous and exothermic. Thomas model fitted well with the breakthrough curves and could describe the dynamic behavior of the column. More significantly, the uptake capacity of ABH-1:3 was still higher than 75% of the maximum adsorption capacity even after ten cycles, indicating that this novel adsorbent can be a promising adsorptive material for removal of MB from aqueous solution under batch and continuous systems. [ABSTRACT FROM AUTHOR]

There is interest in cultivating an economic and controllable method for preparing biomass-based adsorptive materials for efficient removal of dyes from water. Herein a new bead-like material, i.e. alginate-derived carbon beads with a tailored hierarchical structure and surface chemistry, was prepared by using CaCO3-encapsulated calcium alginate (CA) hydrogel beads as the starting material and subsequent controllable carbonization and oxidation treatment. The resultant samples were characterized by SEM, TEM, FTIR, N2 sorption and XRD, etc. Analyses showed that hierarchical carbon beads with a tailored density of oxygen-containing functional groups have been successfully prepared. Adsorption of methylene blue (MB) was studied systematically through batch and column adsorption analyses, and noting the effect of pH, contact time, initial dye concentrations and flow rates. The adsorption kinetics and isotherms fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model, respectively; and the maximum adsorption capacity for MB was 397.9 mg/g. The results indicated that CaCO3/CA-ox could not only significantly improve the adsorption capacity but also exhibited a higher adsorption rate for MB compared with CA. Furthermore, compared to traditional powdery materials, this bead-like porous adsorbent is convenient for column adsorption and scale-up for practical applications, due to the easy regeneration and reusability. [ABSTRACT FROM AUTHOR]

A new 2D Eu-BTB framework ( 1) with stratified gridding structure of about 14.6 Å×16.9 Å was synthesized and characterized. Compound 1 displays excellent water stability with the pH 2-12. The luminescent investigations suggest that 1 could represent a chemical sensor of PO with high sensitivity and selectivity. Importantly, 1 as a sensor of PO can be reused at least five times. On the other hand, the catalytic investigations of 1 were carried out, indicating that 1 could be demonstrated as a recyclable catalyst for CO conversion with epoxides. [ABSTRACT FROM AUTHOR]

A novel magnetic porous sorbent obtained from agricultural waste rice husk was successfully synthesized through a simple carbon-thermal method. The sorbent was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometer, N2 sorption analysis, and X-ray photoelectron spectroscopy. The removal efficiency of the sorbent for Cr(VI) was also investigated. Chromium adsorption was fitted by the pseudo-second-order and Langmuir models. The maximum chromium adsorption capacity, Brunauer-Emmett-Teller surface area, and average Barrett-Joyner-Halenda pore size of the magnetic sorbent were 157. 7mg·g, 134. 1m·g, and 4. 99 nm, respectively. The saturated magnetization of the novel adsorbent was 77. 8 emu·g, indicating that the material can facilitate separation and recovery from aqueous systems. The removal mechanisms of Cr(VI) were also discussed. The result illustrates that rice husk-derived magnetic carbonaceous materials are a potential adsorbent for Cr(VI) pollution treatment and provide a suitable method for the effective conversion of biomass waste, which may solve the problem of waste disposal and widen the applications of the materials. [ABSTRACT FROM AUTHOR]

Composite particles composed of SiO nanoparticles and polystyrene (PS) spheres with a raspberry-like structure were successfully synthesized by a PVP-assistant sol-gel method. The as-prepared products were systemically characterized by FT-IR, TGA, SEM and TEM. The characterization results indicated that the amount of polyvinyl pyrrolidone (PVP) and concentration of ammonia solution played key roles in tailoring the structure of the composite particles, including size and surface density of SiO nanoparticles on the surface of PS spheres. During the PVP-assisted sol-gel process, the synthesized nano-sized SiO particles were favorably deposited on the surface of PS spheres to form hierarchical composite particles. By adjusting the amount of PVP and pH value of reaction system, the typical raspberry-like particles with controllable coverage of SiO nanoparticles on PS spheres were obtained. Subsequently, the composite particles with well controllable morphology were modified with OcTMS and orderly deposited on the substrate. The effect of the composite particles with different morphologies on the wetting property was investigated. Finally, superhydrophobic surface was generated and the water contact angle was up to 154°. Graphical Abstract: PS-SiO composite particles with hierarchical structure were successfully prepared by a PVP-assisted sol-gel method, which exhibited a superhydrophobic property after surface modification with OcTMS.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A novel core-shell-structured Ag-based magnetic functional polymer nanocatalyst, i.e., FeO@SN/GLA@chitosan-Ag (SN represents animo-functionalized SiO, GLA signifies glutaraldehyde), was fabricated via a simple and environmentally friendly method. The magnetic separation property of FeO, the protection effects of SiO, the reduction and stabilization activities of chitosan, and the catalytic property of Ag nanoparticles (NPs) in the multifunctional catalyst system were efficiently combined using glutaraldehyde as bridging agent. The Ag NPs with average diameter about 2-11 nm were generated in situ and stabilized by chitosan, which acted as reducing agent and stabilizer in the absence of other potentially toxic reagents. Furthermore, the reduction, chelation ability of chitosan, and the size of Ag NPs were found to be tunable, thereby enabling the preparation of other noble metal catalysts with tailored properties. Most importantly, the as-prepared catalyst exhibited superior catalytic performance (the reduction reaction was finished within 3 min) and reusability (reusable for at least six times) in the reduction of 4-nitrophenol. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A one-pot method was introduced to fabricate Ag-SiO hollow composite spheres with developed porosity by employing monodisperse carboxylic-capped polystyrene (PS-COOH) spheres as a hard template. During the synthetic process, Ag ions were immediately anchored on the surface of the PS-COOH spheres via electrostatic interaction and readily reduced by employing polymethylhydrosiloxane (PMHS) as a reducing agent. At the same time, silica oligomers derived from the hydrolysis of PMHS and TEOS were slowly deposited on the PS-COOH spheres to form solid silica shells. Subsequent decomposition of the PS-COOH spheres in air induced the formation of Ag-SiO hollow spheres. The as-prepared products were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and N absorption-desorption study. The results show that the well-designed composite spheres featured thin and spherical silica shell (~10 nm), large surface area (>240 m g) and mesopore (6.0-9.0 nm). In addition, the Ag-SiO hollow composite spheres exhibited high catalytic performance toward the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Graphical Abstract: A one-pot method was reported to prepare Ag-SiO hollow spheres with well-developed porosity, which exhibited high catalytic performance and durable activity for the reaction of 4-NP to 4-AP.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

This work presented a novel, facile, cost-effective and environmentally friendly approach for the preparation of magnetic core-shell structured catalyst i.e. FeO@SN-Ag (abbreviation of FeO@SiO-NH-Ag). During the process of preparation, Ag nanoparticles were in situ generated with amino groups in the surface of FeO@SN serving as green reductant and stabilizer in the absence of any additional toxic reductant or organic reagent. Magnetic core, FeO, was easily prepared through solvothermal method. The subsequent coating and surface amino functionalization of SiO was accomplished via one-pot sol-gel method, which was green and time-saving. What's more, the resulting catalyst exhibited excellent catalytic property (the reaction was finished within 2 min) and reusability (reused at least seven times) in the reduction of 4-nitrophenol. [ABSTRACT FROM AUTHOR]

A newly designed two-step acid-base sol-gel method for the synthesis of Ag-doped hybrid materials with tailored physicochemical properties is presented. In the proposed protocol, Ag is in situ reduced by Si-H bonds of polymethylhydrosiloxane (PMHS) in the absence of an additional reductant. Hydrolysis of the alkyloxysilane groups of tetraethoxysilane and PMHS or 3-mercaptopropyltrimethoxysilane (MPTMS) can be promoted by the release of H due to complexation between Ag/Ag and thiol groups. Newly formed nanosilver can be fully stabilized by a sol-gel reaction and embedded parallel to the skeletons. The MPTMS dosage used during synthesis has a significant impact on the textural characteristics of the final products. The properties of as-prepared materials are characterized by Brunauer-Emmett-Teller analysis, transmission electron microscopy, and X-ray photoelectron spectroscopy. This study presents a novel method for the synthesis of Ag-doped hybrid materials using the synergetic effects of common organosilane precursors. [ABSTRACT FROM AUTHOR]

A rare earth ytterbium complex with 2,4,6-pyridinetricarboxylic acid (Hpta) has been synthesized by hydrothermal method, the formula is {[Yb(pta)(HO)]·HO}. The complex crystallized in monoclinic system, P2/c space group with lattice parameters a = 11.6556(19)Å, b = 7.8364(12), c = 22.020(4), α = γ = 90º, β = 92.120(3), Z = 4, GOF = 1.026, R1 = 0.0334, wR2 = 0.0660. The pta anions connect four rare earth Yb(III) ions with two different coordination modes. The complex exhibit intense characteristic near-infrared luminescence of Yb(III) ions at 990 nm with excitation of UV-rays. [ABSTRACT FROM AUTHOR]

Multifunctional nanomaterials with task-specific physicochemical properties, especially core-shell nanostructures with FeO core and NH-functional shells (FeO@SiO-NH), have been extensively investigated as high-performance adsorbents, catalysts and catalyst supports; and in most cases the controllable sol-gel technique is the choice for fabrication of this kind of widely applied materials. Herein, we demonstrated that mono-dispersed and spherical FeO@SiO-NH nanomaterials with magnetic response core, NH-functional shell structure can be facilely prepared by co-condensation of TEOS with APTMS using a versatile sol-gel process. It was shown that the proper usage of APTMS and appropriate pre-hydrolysis time of TEOS were crucial and key steps for formation of highly uniform and desirable amino loading FeO@SiO-NH materials. The TEOS pre-hydrolysis and the critical time (around 90 min) before the addition of APTMS prove to be vital for uniform structure evolution, while the appropriate concentration of APTMS (~2.28 mmol L in our system) leads to well-dispersed materials with relatively high loading of amino functionality. The as-prepared FeO@SiO-NH magnetic nanoparticles prepared under optimum conditions possessing superparamagnetic behavior, uniform core-shell structure (~200 nm in diameter), relatively large BET surface area (~138 m/g) and high incorporation of amino-functionality (~2.90 wt %). [ABSTRACT FROM AUTHOR]

A facile sol-gel route to the fabrication of size-controllable nanosilver embedded hybrid materials at room-temperature is presented. The preparation process involves using three kind of organosilica precursors, i.e. tetraethoxysilane, 3-mercaptopropyltrimethoxysilane and polymethylhydrosiloxane, which behaved as framework constructor, complexing agent toward metal ions and in situ reducing agent for Ag ions, respectively, under alcohol-rich synthesis conditions. The prepared hybrid materials were characterized by Ultraviolet-visible diffuse reflectance spectra, Fourier transform infrared, transmission electron microscopy, X-ray diffraction, nitrogen adsorption-desorption measurements. It was shown that well-dispersed silver nanoparticles (AgNPs) with small particle size were successfully embedded in the hybrid skeleton, and the mean particle size of AgNPs could be controlled at ca. 2-5 nm. [ABSTRACT FROM AUTHOR]

Adsorption of heavy metal ions from aqueous solutions on tri-amino-functionalized silica hybrids with tailored structural characteristics was investigated. The adsorbents were prepared using a controllable sol-gel method with (3-aminopropyl)trimethoxysilane or 3-[2-(2-aminoethylamino)ethylamino] propyltrimethoxysilane, polymeric polymethylhydrosilane and tetraethoxysilane as co-precursors in the absence of traditional surfactant aggregates. These as-prepared hybrids possess tailored structures with high specific surface area, large pore volumes and relatively narrow pore diameter as confirmed by transmission electron microscopy and nitrogen sorption results. The elemental analysis and FT-IR indicated that amino groups had been successfully introduced into the opened skeletons. The loadings of amino moieties of the amino-functionalized gels could be tuned from 5 to 40% by adjusting the molar ratio of organoalkoxysilane/silica in the synthesis system. The heavy metal adsorption experiments have been examined for Cu(II), Pb(II), Ni(II), Cd(II) and Zn(II) from aqueous solution employing batch method. The results showed that the adsorption capacity of the tri-amino-functionalized adsorbents was higher than that of the mono-amino-functionalized counterparts, illustrating a good potential for environmental remediation in virtue of the combination of selective adsorption performance and large-scale synthesis character. [ABSTRACT FROM AUTHOR]

Thiol-functionalized sol-gel materials with porous structures were successfully prepared via co-condensation of tetraethoxysilane, (3-mercaptopropyl)-trimethoxysilane, polymeric polymethylhydrosiloxane in the absence of traditional structure-directing agents under proposed basic conditions. The dependence of textural characteristics on the preparation parameters were investigated employing various techniques as such N adsorption/desorption isotherms, SEM, TG-DTG, FT-IR and solid state Si MAS NMR measurements. It was shown by these characterizations that thiol-functional groups have been successfully introduced into the porous network and the loadings could be tuned by adjusting the content of corresponding precursor in the gel system. Besides, the as-prepared samples exhibited high surface areas, large pore volume, tunable pore diameters and favorable thermal stability. Adsorption experiments indicated that thiol-incorporated materials have selective adsorption ability toward heavy metal ions from aqueous solutions, and a high capacity in adsorbing heavy metal ion of Pb (up to 99.4%) was observed under optimized experimental conditions. [ABSTRACT FROM AUTHOR]

Hybrid materials based on tetraethoxysilane (TEOS) and polymethylhydrosiloxane (PMHS) have been prepared employing sol-gel synthesis pathway, and the effects of preparation parameters such as PMHS concentration, water and NaOH amount on the structural characteristics were detailed investigated based on various techniques. It is illustrated that structural characteristics especially pore size can be tuned readily by adjusting the amount of PMHS during the sol-gel reaction. Furthermore, pore size increases with water amount and contrarily is almost independent on the amount of sodium hydroxide (NaOH) added in the sol-gel process. Typical hybrid sample prepared with desirable preparation parameters presents disordered wormhole structure with uniform mesopores, developed porosity with high specific surface area and pore volume and stable framework. In virtue of facileness and tunable composition, this synthesis pathway can be favorably applied for the preparation of other fascinating materials, i.e. porous ceramics, hydrophobic coatings and aerogels as well. [ABSTRACT FROM AUTHOR]

Diatoms are one of the predominant contributors to global carbon fixation by accounting for over 40% of total oceanic primary production and dominate export production. They play a significant role in marine biogeochemistry cycle. The diatom mat deposits are results of vast diatoms bloom. By analysis of diatom mats in 136°00′-140°00'E,15°00'?21°00'N, Eastern Philippines Sea, we identified the species of the diatoms as giant Ethmodiscus rex (Wallich) Hendey. AMS 14C dating shows that the sediments rich in diatom mats occurred during 16000-28600 a B.P., which means the bloom mainly occurred during the last glacial period, while there are no diatom mat deposits in other layers. Preliminary analysis indicates that Antarctic Intermediate Water (AAIW) expanded northward and brought silicate-rich water into the area, namely, silicon leakage processes caused the bloom of diatoms. In addition, the increase of iron input is one of the main reasons for the diatom bloom. [ABSTRACT FROM AUTHOR]