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Abstract: (FePt)100−x Au x (x=0, 5, 10, and 20) nanoparticles were synthesized by the sol–gel method, and effects of Au content on the structural and magnetic properties of samples were investigated. Au doping reduced the phase transition temperature from face-centered cubic (FCC) to face-centered tetragonal (FCT) structure. In addition, additive Au promotes the chemical ordering of L10 FePt NPs and increases the grain size of L10 FePt NPs. When Au content increased from 0 to 10at%, the coercivity (H c ) increased due to the increase in degree of ordering S and grain size of L10 FePt NPs. By increasing the Au content to 20at%, H c decreased. [Copyright &y& Elsevier]

Abstract: The Fe x Pt100−x nanoparticles (NPs) with different nominal atomic rations (30≤x≤80) were synthesized at 700°C by the sol–gel method. The structure, morphology and magnetic properties of the samples were investigated. When the Fe content in the Fe–Pt alloy NPs was 30at%, FePt3 NPs were successfully synthesized. With the increase in Fe content up to 50at%, it was found that the superlattice reflections (001) and (110) appeared, which indicated the formation of the L10-FePt phase. Meanwhile, the FePt3 fraction was reduced. When the Fe content increased to 60at%, single-phase L10-FePt NPs were synthesized. The coercivity (Hc), saturation magnetization (Ms) and chemical order parameter S for Fe60Pt40 NPs were as high as 10,200Oe, 17.567emu/g and 0.928, respectively. With the further increase of the Fe content to 80at%, only Fe3Pt phase existed and the Hc of the Fe3Pt NPs decreased drastically to 360Oe. [Copyright &y& Elsevier]

Abstract: Visual working memory (VWM) allows us to hold visual information briefly in our minds after its disappearance. It is important for bridging the present to the immediate past. Previous neuroscience studies on VWM have shown that several parietal, frontal, and occipitotemporal brain regions subserve this function. Those studies, however, have often focused on VWM for a single property, such as color. Yet, in behavior, the capacity of VWM is sensitive to the complexity of to-be-remembered visual features. How do different brain areas represent VWM for visual features of different complexity and for combination of features? To address this question, we used functional MRI to study the response profile of several brain regions in three VWM tasks. In all tasks, subjects saw 1 to 7 colored polygons and had to remember their color (a simple feature), shape (a complex feature), or both color and shape. Behavioral performance showed that VWM reached capacity limit at about 3 colors, 2 shapes, and 2 compound objects. In the fMRI data, we found different functional profiles for frontal, parietal, and occipitotemporal regions. Specifically, the posterior parietal cortex was sensitive to both featural and VWM load manipulations. The prefrontal regions were sensitive to VWM load manipulation but relatively insensitive to featural differences. The occipitotemporal regions were sensitive to featural differences, but not to VWM load manipulation. We propose that the response properties of these regions can jointly account for several findings in human VWM behavior. [Copyright &y& Elsevier]

The human cognitive system is severely limited in the amount of information it can process simultaneously. When two tasks are presented within a short stimulus-onset-asynchrony (SOA), reaction time of each task, especially task 2, is dramatically delayed. Previous studies have shown that such delay is accompanied by increased activation in the right inferior frontal gyrus (GFi). In this study, we address the role of right GFi in resolving dual-task interference at two different stages: allocation of perceptual attention and response selection. We scan 12 subjects using functional MRI while they conduct two tasks—shape discrimination in task 1 and color discrimination in task 2—and vary the SOA between tasks as 100 or 1500 ms. The targets are located at the center or at the periphery. When both are at the center, they compete primarily for response selection. When both are at the periphery, they additionally compete for the allocation of perceptual attention. Results show that the right GFi and frontal operculum regions are significantly more active in the short SOA than the long SOA condition, but only when subjects attend to the periphery in both tasks. We conclude that the right lateral frontal regions are important for resolving dual-task interference at the perceptual attention stage. [Copyright &y& Elsevier]

Presents the relationship of spatial attention and memory in optimizing visual processes. Factors that increase the efficacy of attentional deployment; Investigations on the learning of visual context.

[Display omitted] • A SERS platform for simultaneous detection of E. coli and S. aureus was developed. • A dual SERS enhancement strategy based on sandwich-like structure was applied. • Aptamers modified-Fe 3 O 4 @SiO 2 -Au NCs were used for bacterial capture and isolation. • GO-Au NSs functionalized with DTNB/4-MBA and aptamers were proposed as SERS tags. • The detection limit for E. coli and S. aureus was as low as 10 cfu/mL. In this work, a novel surface-enhanced Raman scattering (SERS) sandwich strategy biosensing platform has been established for simultaneously detecting Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Fe 3 O 4 @SiO 2 -Au nanocomposites (NCs) with varying amounts of Au nanocrystals were prepared, and the effect of interparticle gaps on SERS activity was studied by finite-difference time-domain (FDTD) method. The optimal magnetic SERS-active substrates (FS-A5) were functionalized with the specific aptamers to act as capture probes. Meanwhile, graphene oxide-Au nanostars (GO-Au NSs) decorated with Raman reporters and aptamers were used as SERS tags. The loading density of Au NSs on GO was tuned to change the number of SERS active sites. In this proposal, E. coli and S. aureus were first captured by capture probes and then bound with SERS tags to form a sandwich-like structure, which caused enhanced electromagnetic field because of the dual enhancement strategy. Under optimal conditions, SERS platform could detect E. coli and S. aureus simultaneously, and the detection limit was as low as 10 cfu/mL. Our sandwich assay-based dual-enhanced SERS platform provides a new idea for simultaneously detecting multiple pathogens with high selectivity and sensitivity, and thus will have more hopeful prospects in the field of food safety. [ABSTRACT FROM AUTHOR]

Toll-like receptors (TLRs) are central players in the innate immune system in response to a wide range of pathogen infection. Among various TLRs, TLR4 plays a key role in recognition of bacterial lipopolysaccharides (LPS). In the present study, we identified and characterized a novel TLR4 homologue ( maTLR4b ) in blunt snout bream ( Megalobrama amblycephala ) which was significantly distinct from previously reported M. amblycephala TLR4 (tentatively named maTLR4a ). The results showed that the complete cDNA sequence of maTLR4b was 3261 bp with an open reading frame encoding a polypeptide of 820 amino acids, and that its genomic sequence was 3793 bp, which had 3 exons. Structurally, the deduced maTLR4b protein showed a typical TLR domain architecture, including a signal peptide, eight leucine-rich repeats (LRRs) in the extracellular region, a transmembrane domain, and a Toll-Interleukin 1 receptor (TIR) domain in the cytoplasmic region. Phylogenetic analysis revealed that all TLR4s from teleost fish formed a monophyletic clade. Both maTLR4a and maTLR4b were divided into two distinct branches, and showed the highest level of similarity with the grass carp TLR4.2 and TLR4.4 homologue, respectively. MaTLR4b was constitutively expressed in all healthy tissues tested although at different levels. After LPS stimulation, the expression levels were significantly up-regulated in spleen, and peaked at 4 h between maTLR4a and maTLR4b , but with a distinct and complementary expression patterns. Taken together, these results suggested that maTLR4b is indeed a functional homologue of TLR4 in other species, which may play vital role in innate immune. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe 3 O 4 /Cu 2 O-Ag nanocomposites (NCs) were designed and synthesized successfully. • We realized integration of SERS detection and photocatalytic degradation for PAHs. • Effect of Ag contents on SERS and catalytic activity of Fe 3 O 4 /Cu 2 O-Ag was studied. • SERS detection limit of Fe 3 O 4 /Cu 2 O-Ag towards PAHs was as low as 10-9 to 10-10 M. • Photocatalytic mechanism of PAHs degradation by Fe 3 O 4 /Cu 2 O-Ag was proposed. Polycyclic aromatic hydrocarbons (PAHs) with carcinogenic, teratogenic and mutagenic properties are persistent organic pollutants in the environment. Herein, the novel multifunctional Fe 3 O 4 /Cu 2 O-Ag nanocomposites (NCs) have been established for ultra-sensitive surface-enhanced Raman scattering (SERS) detection and visible light-driven photocatalytic degradation of PAHs. Fe 3 O 4 /Cu 2 O-Ag NCs with different amounts of Ag nanocrystals were synthesized, and the effect of Ag contents on SERS performance was studied by finite-difference time-domain (FDTD) algorithm. The synergistic interplay of electromagnetic and chemical enhancement was responsible for excellent SERS sensitivity of Fe 3 O 4 /Cu 2 O-Ag NCs. The limit of detection (LOD) of optimal SERS substrates (FCA-2 NCs) for Nap, BaP, Pyr and Ant was as low as 10-9, 10-9, 10-9 and 10-10 M, respectively. The SERS detection of PAHs in actual soil environment was also studied. Moreover, a simple SERS method was used to monitor the photocatalytic process of PAHs. The recovery and reuse of Fe 3 O 4 /Cu 2 O-Ag NCs were achieved through magnetic field, and the outstanding SERS and photocatalytic performance were still maintained even after eight cycles. This magnetic multifunctional NCs provide a unique idea for the integration of ultra-sensitive SERS detection and efficient photocatalytic degradation of PAHs, and thus will have more hopeful prospects in the field of environmental protection. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe 3 O 4 /Cu 2 O-Ag nanocomposites (NCs) were designed and synthesized successfully. • We realized integration of SERS detection and photocatalytic degradation for PAHs. • Effect of Ag contents on SERS and catalytic activity of Fe 3 O 4 /Cu 2 O-Ag was studied. • SERS detection limit of Fe 3 O 4 /Cu 2 O-Ag towards PAHs was as low as 10-9 to 10-10 M. • Photocatalytic mechanism of PAHs degradation by Fe 3 O 4 /Cu 2 O-Ag was proposed. Polycyclic aromatic hydrocarbons (PAHs) with carcinogenic, teratogenic and mutagenic properties are persistent organic pollutants in the environment. Herein, the novel multifunctional Fe 3 O 4 /Cu 2 O-Ag nanocomposites (NCs) have been established for ultra-sensitive surface-enhanced Raman scattering (SERS) detection and visible light-driven photocatalytic degradation of PAHs. Fe 3 O 4 /Cu 2 O-Ag NCs with different amounts of Ag nanocrystals were synthesized, and the effect of Ag contents on SERS performance was studied by finite-difference time-domain (FDTD) algorithm. The synergistic interplay of electromagnetic and chemical enhancement was responsible for excellent SERS sensitivity of Fe 3 O 4 /Cu 2 O-Ag NCs. The limit of detection (LOD) of optimal SERS substrates (FCA-2 NCs) for Nap, BaP, Pyr and Ant was as low as 10-9, 10-9, 10-9 and 10-10 M, respectively. The SERS detection of PAHs in actual soil environment was also studied. Moreover, a simple SERS method was used to monitor the photocatalytic process of PAHs. The recovery and reuse of Fe 3 O 4 /Cu 2 O-Ag NCs were achieved through magnetic field, and the outstanding SERS and photocatalytic performance were still maintained even after eight cycles. This magnetic multifunctional NCs provide a unique idea for the integration of ultra-sensitive SERS detection and efficient photocatalytic degradation of PAHs, and thus will have more hopeful prospects in the field of environmental protection. [ABSTRACT FROM AUTHOR]

Bactericidal permeability-increasing protein (BPI) and lipopolysaccharide-binding protein (LBP) belong to the lipid transfer protein/lipopolysaccharide-binding protein family and play a critical role in the innate immune response to Gram-negative bacteria. In the present study, a novel BPI/LBP from blunt snout bream, Megalobrama amblycephala (maBPI/LBP) was isolated by RACE techniques. The open reading frame (ORF) of maBPI/LBP gene encoded a polypeptide of 474 amino acids with a putative 18-aa hydrophobic signal peptide. Structurally, the maBPI/LBP showed highly similar to those of BPI/LBPs from invertebrate and teleost, LBPs and BPIs from mammal, which contained an N-terminal BPI/LBP/CETP domain BPI1 with a LPS-binding domain, a C-terminal BPI/LBP/CETP domain BPI2, and proline-rich domain. The homologous identities of deduced amino acid sequences displayed that the maBPI/LBP possessed significant similarity (96.61% and 90.07%) with those of grass carp and common carp, respectively. The recombinant protein of maBPI/LBP showed effectively kill Gram-negative bacteria. The maBPI/LBP gene was expressed in a wide range of normal tested tissues, with the highest expression levels in the kidney. The experiments revealed that the mRNA expression of maBPI/LBP in spleen considerably up-regulated from 2 h to 8 h post LPS stimulation, and peaked rapidly at 2 h (7.40-fold, P < 0.05), which confirmed that maBPI/LBP was the absolute sensitive to LPS stimulation. Furthermore, the level of maBPI/LBP mRNA expression reached the maximum for a second time at 24 h after LPS stimulation. These results suggested that maBPI/LBP was a constitutive and inducible acute-phase protein contributing to the host immune defense against pathogenic bacterial infection in M . amblycephala . This study will further our understanding of the function of BPI/LBP and the molecular mechanism of innate immunity in teleost. [ABSTRACT FROM AUTHOR]

Abstract: Equiatomic L10 CoPt alloy nanoparticles (NPs) with various contents of SiO2 are synthesized by the simple sol–gel method. The SiO2 additions restrain the growth of grain and hinder the agglomeration formation. The coercivity increases first and then decreases with SiO2 addition. Compared to the 0μl-SiO2 CoPt NPs, the higher ordering degree and better magnetic properties are obtained by the addition of amount 10μl SiO2 in our sample. And the coercivity is two times as large as that of 0μl-SiO2 NPs. When the addition of SiO2 is more than 10μl, the deteriorated magnetic properties are ascribed to the transformation from hard magnetically phase to soft magnetically phase due to the decrease of particle size. [Copyright &y& Elsevier]

Multifunctional nanocomposites with well-defined structures and optimized electromagnetic properties are highly desirable in surface-enhanced Raman scattering (SERS) and catalytic reduction reactions. We report a novel multifunctional Fe 3 Pt–Ag nanoparticle with efficient SERS performance and excellent catalytic activity. Fe 3 Pt–Ag shows an obviously enhanced SERS effect, which is evaluated by enhanced Raman signal of Rhodamine B (RhB). Efficient SERS performance of Fe 3 Pt–Ag is attributed to the optical property of local surface plasmon resonance of Ag nanoparticles (NPs). Importantly, spontaneous catalytic reduction reactions of RhB illustrate that Fe 3 Pt–Ag possesses good catalytic performance. In combination with the theories of pseudo-first-order kinetics, catalytic reduction reactions are analysed in detail, and experimental data are in line with theoretical results. Fe 3 Pt–Ag can be easily recycled at least six times via an external magnetic field, elaborating that our developed Fe 3 Pt–Ag can be applied to protect environment as a novel composite material. The Fe 3 Pt nanoparticles and Fe 3 Pt–Ag nanocomposite were fabricated by the sol-gel and seed deposition method, respectively. The Fe 3 Pt–Ag shows an obviously enhanced SERS effect, which is evaluated by enhanced Raman signal of Rhodamine B (RhB). The spontaneous catalytic reduction reactions of RhB illustrate that Fe 3 Pt–Ag possesses good catalytic performance. The Fe 3 Pt–Ag can be efficiently recovered and recycled in the reaction mixture by magnetic separation. Image 1 • Fe 3 Pt and Fe 3 Pt–Ag nanocomposites were prepared by a facile method. • Fe 3 Pt–Ag nanocomposites show good separation ability and reusability. • Fe 3 Pt–Ag nanocomposites have high SERS effect for Rhodamine B. • Fe 3 Pt–Ag nanocomposites have good catalytic performance for Rhodamine B. [ABSTRACT FROM AUTHOR]