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Neural activity and behavior vary within an individual (states) and between individuals (traits). However, the mapping of state-trait neural variation to behavior is not well understood. To address this gap, we quantify moment-to-moment changes in brain-wide co-activation patterns derived from resting-state functional magnetic resonance imaging. In healthy young adults, we identify reproducible spatiotemporal features of co-activation patterns at the single-subject level. We demonstrate that a joint analysis of state-trait neural variations and feature reduction reveal general motifs of individual differences, encompassing state-specific and general neural features that exhibit day-to-day variability. The principal neural variations co-vary with the principal variations of behavioral phenotypes, highlighting cognitive function, emotion regulation, alcohol and substance use. Person-specific probability of occupying a particular co-activation pattern is reproducible and associated with neural and behavioral features. This combined analysis of state-trait variations holds promise for developing reproducible neuroimaging markers of individual life functional outcome. Neural activity and behavior vary within and between individuals, but how these variations are linked to behavior is not well understood. This neuroimaging study shows that the human brain shows co-activation patterns that are highly reproducible and associated with neural and behavioral features. [ABSTRACT FROM AUTHOR]

The evolution process of magnetic domains in response to external fields is crucial for the modern understanding and application of spintronics. In this study, we investigated the domain rotation in stripe domain films of varying thicknesses by examining their response to microwave excitation in four different orientations. The resonance spectra indicate that the rotation field of stripe domain film under an applied magnetic field approaches the field where the resonance mode of sample changes. The saturation field of the stripe domain film corresponds to the field where the resonance mode disappears when measured in the stripe direction parallel to the microwave magnetic field. The results are reproducible and consistent with micromagnetic simulations, providing additional approaches and techniques for comprehending the microscopic mechanisms of magnetic domains and characterizing their rotation. [ABSTRACT FROM AUTHOR]

We investigated femto- and picosecond-time magnetization dynamics in a ferromagnetic Ni80Fe20 film with varying thicknesses (wedge-shaped film). We observed that the thickness gradient strongly affects the magnetic moment distribution, causing a magnetization reorientation from in-plane to out-of-plane, and formatting a stripe domain (SD) at the thicker end of the wedge. The magnetization dynamics measurements reveal that the part of the film displaying SDs follows a substantially faster demagnetization and magnetization recovery and smaller magnetization quenching compared to the in-plane domain film. The experiments and micromagnetic simulations support that the decrease in relaxation time is caused by a magnetic anisotropy of the films introduced by SD formation. Our results point out that the micromagnetic structure plays an important role in the magnetization dynamics in ferromagnetic films after optically triggered demagnetization. [ABSTRACT FROM AUTHOR]

Heterocyclic aromatic amine molecularly imprinted polymer nanospheres with surface-bound dithioester groups (haa-MIP) were firstly synthesized via reversible addition-fragmentation chain transfer (RAFT) precipitation polymerization. Then, a series of core-shell structural heterocyclic aromatic amine molecularly imprinted polymer nanospheres with hydrophilic shells (MIP-HSs) were subsequently prepared by grafting the hydrophilic shells on the surface of haa-MIP via on-particle RAFT polymerization of 2-hydroxyethyl methacrylate (HEMA), itaconic acid (IA), and diethylaminoethyl methacrylate (DEAEMA). The haa-MIP nanospheres showed high affinity and specific recognition toward harmine and its structural analogs in organic solution of acetonitrile, but lost the specific binding ability in aqueous solution. However, after the grafting of the hydrophilic shells on the haa-MIP particles, the surface hydrophilicity and water dispersion stability of the polymer particles of MIP-HSs greatly improved. The binding of harmine by MIP-HSs with hydrophilic shells in aqueous solutions is about two times higher than that of NIP-HSs, showing an efficient molecular recognition of heterocyclic aromatic amines in aqueous solution. The effect of hydrophilic shell structure on the molecular recognition property of MIP-HSs was further compared. MIP-PIA with carboxyl groups containing hydrophilic shells showed the highest selective molecular recognition ability to heterocyclic aromatic amines in aqueous solution. [ABSTRACT FROM AUTHOR]

Several smokeless tobacco products are available in the market and comprise complex chemical matrices. Sample preparation for analysis of the multiple classes of harmful compounds in smokeless tobacco products is highly cumbersome. In this study, a simultaneous extraction scheme was developed for three toxic analyte classes in smokeless tobacco products using a two‐phase solution consisting of 5% aqueous NaOH and dichloromethane in a 1:4 ratio. The dichloromethane extract was used to analyze four alkaloids directly at levels greater than parts per million; however, passing the layer through a silica cartridge for further purification and concentration was necessary for determining 18 polycyclic aromatic hydrocarbons and four volatile N‐nitrosoamines at the ppt level. The multitargets were determined by using gas chromatography with tandem mass spectrometry. The limits of detection for the 18 polycyclic aromatic hydrocarbons, four volatile N‐nitrosoamines, three minor alkaloids, and nicotine were 0.2‐1.2, 0.2‐0.4, 0.6‐1.0, and 10.2 μg/g, respectively. Four different smokeless tobacco substrates were fortified with three levels of mixed standards, and the recoveries ranged between 83 and 110%. The method was highly efficient, reduced the sample amounts, solvents, and the time required by approximately 60%. The method was used to assay 18 smokeless tobacco products, and showed potentials in assaying drugs and other plant‐based substrates. [ABSTRACT FROM AUTHOR]

• FMR and spin waves resonance excitation of nano-brush are investigated. • The Fe nanowire arrays could destroy the stripe domain structure in Fe 25 Ni 75 film. • The nano-brush samples exhibit perpendicularly oriented easy axes. The magnetic heterostructures, consisting of Fe nanowire arrays (FNWs) and Fe 25 Ni 75 film, are prepared by combining electrochemical deposition and RF magnetron sputtering. The ferromagnetic resonance (FMR) property in the magnetic heterostructures is investigated by using frequency sweep mode and field sweep mode. The results of hysteresis loops and permeability spectra indicate that the FNWs could destroy the stripe domain structure in Fe 25 Ni 75 film. The resonance absorption near the FMR field is excited in the heterostructures, which can be attributed to the spin non-uniform precession namely spin waves resonance excitation. [ABSTRACT FROM AUTHOR]

The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is classified as a Group 1 human carcinogen. It is metabolically activated by P450 enzymes to intermediate methylate and pyridyloxobutylate DNA, resulting in the formation of DNA adduct that is critical for the carcinogenicity of NNK. To directly and objectively examine the DNA adduct formation profiles without the complexity of factors in vivo, in the present study, five kinds of methyl DNA adducts were first identified in the incubation model of NNK established with human lung epithelial cells (BEAS-2B). The level of methyl DNA adducts and metabolites of NNK were quantitatively analyzed, respectively. With the increase of exposure time and dose, the level of methyl DNA adducts and metabolites increased. Furthermore, with the changes of the activity of P450 enzymes, which is the main enzyme regulating the α-hydroxylation of NNK, we found the levels of both methyl adducts and metabolites formed via α-hydroxylation in experimental groups showed the same trend compared with those in control group, while the metabolites formed via other pathways changed in the opposite trend. The result proves that the methyl adducts induced by NNK generate via α-hydroxylation pathway in BEAS-2B cells. [ABSTRACT FROM AUTHOR]

Through a systematic investigation of the magnetization rotation and reversal in an exchange‐biased NiFe/MnIr film electrically detected by spin rectification effect (SRE), we experimentally demonstrate that this SRE DC voltage can be detected in the field‐swept spectra both at resonant and nonresonant conditions. The spectra show clear shifted hysteretic curves driven by exchange bias and a hysteresis loop is formed at applied magnetic field around exchanged bias field by the nonzero SRE DC voltage with sign change with the sweeping direction. More interestingly, we found that the voltage magnitude changes upon switching of magnetization can be greatly enhanced at resonance thereby suggesting an attractive approach to realize a highly sensitive method to measure exchange bias field. This experimental behavior can be interpreted within the framework of the near‐resonant spin rectification effect. [ABSTRACT FROM AUTHOR]

In this paper, a serious of CoFeB films of 30 nm prepared by a DC magnetron sputtering on Si substrates with different roughness etched by NaOH solution are investigated. It is found that the coercivity ( H c ) and effective damping coefficient α are influenced by the substrate roughness of the films. As the substrate roughness increased to 73.9 nm, the H c ranged from 14.4 Oe to 81.4 Oe; the α, from 0.012 to 0.11 at the same time. It is attributed to the function of magnetic moment pinning and magnon-magnon scattering caused by the rough substrate. Thus, the tunable performances of soft magnetism and high frequency of CoFeB films make them become potential candidates for microwave-based devices and other tunable microwave devices. [ABSTRACT FROM AUTHOR]

Periodic micro-stripes arrays with stripe domains structures upon continuous permalloy (Py) film were fabricated by sputtering, photolithography and ion beam etching technology. These samples display in-plane magnetic anisotropy, and stripe domains structure is observed by the magnetic force microscopy (MFM) in the area of the micro-stripes. The periodic micro-stripes show an effective impact on static and dynamic magnetic properties of Py continuous film. In the case of dynamic magnetic properties, the resonance frequency f r of these samples can be tuned by periodic micro-stripes arrays. Compared to continuous film with resonance frequency f r of 0.64 GHz, the f r of composite structures can be tuned by the separation gap of periodic micro-stripes arrays from 0.8 GHz to 2.3 GHz at zero-field. At the same time, the f r could be also tuned by rotating the samples within the plane. This attributes to the competition of shape anisotropy induced by micro-stripes and the dynamic anisotropy originating by stripe domains structure. [ABSTRACT FROM AUTHOR]

A new supramolecular host-bonded stationary phase for high-performance liquid chromatography (HPLC) was prepared by coupling a 26-membered aromatic-aliphatic-mixed azamacrocycle to 3-chloropropyltrimethoxylsilane-modified silica, which was characterized by infrared spectroscopy and elemental analysis. To understand the role of functional groups and the nano-sized cavity on the azamacrocycle for its chromatographic performance, the chromatographic behavior of the new stationary phase was investigated by using alkylbenzenes, polycyclic aromatic hydrocarbons (PAHs), aromatic amines, and aromatic positional isomers as probes. This stationary phase exhibited a unique chromatographic retention, which was characterized by multiple interactions between the stationary phase and analytes, including hydrophobic, π–π, hydrogen-bonding, and inclusion interactions. At the same time, the embedded azamacrocycle showed remarkable superiority over the C18 phase in terms of shape, planarity, and isomeric recognition in discriminating specific PAHs and isomers and overcoming the negative effect of residual silanol groups. Such a hybrid stationary phase is more versatile and shows great potential in the analysis of complex samples. [ABSTRACT FROM AUTHOR]

The influence of cycle rapid cooling treatment on the giant magnetoimpedance (GMI) properties in Co-based amorphous alloys was investigated. Hysteresis loops show that the saturation magnetization of ribbons has been improved by cycle treatment. It can be found that the GMI ratio was increased from 89% to 130% at 1 MHz by the thermal cycle ( TC ) treatment. Moreover, GMI ratio of TC treatment sample increased up to 321% at 5 MHz. It is considered that internal thermoelastic stress leads to surface roughness, magnetic domain structures and saturation magnetization changes of the ribbons during different cycle processes. It was also found that the asymmetric GMI (AGMI) phenomenon occurred in the Co-based alloys with TC treatment after annealing, which can be regarded as a new method to get GMI-valve to improve GMI sensitivity. [ABSTRACT FROM AUTHOR]

The magnetic properties of various samples were investigated through vibrating sample magnetometer, electron spin resonance (ESR), and vector network analyzer ferromagnetic resonance (VNA-FMR) techniques, respectively. The corresponding saturation magnetization 4\pi Ms and in-plane magnetic anisotropy field Hk of those different films were estimated by the three methods. A comparative investigation of the three techniques, especially for ESR and VNA-FMR, on the estimation of 4\pi Ms and Hk was analyzed systematically. The influence of omitted Hk on the data of 4\pi Ms and Hk was also studied. The results provide a quite clear conclusion for the measurements of 4\pi Ms and H\mathbf {k} in different conditions. [ABSTRACT FROM AUTHOR]

Amadori compounds are aroma precursors formed in the initial phase of the Maillard reaction. Based on their similar structures, simultaneous quantification of more than six Amadori compounds in tobacco has not been reported yet. In this study, a simple and rapid method was developed to simultaneously quantify ten Amadori compounds including the isomers of Fructose-isoleucine and Fructose-leucine in tobacco. The separation was performed on an Atlantis T3 column (2.1 × 250 mm, 5 μm) by gradient elution using acetonitrile and water as the mobile phases. The quantification method was systematically evaluated and proven to be sensitive and accurate. The linearity was good, with correlation coefficients of 0.9977-0.9999. The limits of detection and quantitation were 1.354-2.532 and 4.516-8.444 ng/mL, respectively. The recoveries were 84.0-119.6%, and the relative standard deviations were 1.33-5.40%. The method was used to analyze the changes in the amounts of ten Amadori compounds in tobacco before and after tobacco primary processing. The analysis shows that the Maillard reaction occurs during the short processing period. [ABSTRACT FROM AUTHOR]

We have successfully prepared a series of sulfur-doped cobalt ferrite nanoparticles via a facile and novel calcining process in air. The technique requires neither pH regulation nor a gas atmosphere nor centrifugation nor any other supplementary reagents during the preparation process. Our various characterizations confirmed that the nonmetal sulfur element was successfully doped in the cobalt ferrite nanoparticles. As the sulfur concentration was increased, the shapes of the sulfur-doped cobalt ferrite nanoparticles changed, from compact microspheres to sparse coral-like nanoparticles. Significantly, the saturation magnetization of sulfur-doped cobalt ferrites was measured to be as high as 81 emu g−1, which is particularly different from the decreased saturation magnetization of previously reported metal element doping. [ABSTRACT FROM AUTHOR]

A step-like FeNi film was fabricated by electrodeposition. The cross section morphology and the surface magnetic properties were performed by scanning electron microscopy and nano-MOKE, respectively. The section morphology of the thicker step was presented as a result of columnar structure. The magneto-optic Kerr effect (MOKE) results for every step show the change of surface magnetic properties with the increasing step thickness. Moreover, the coercivity and remanence ratio decrease, accompanying the step thickness increases. Significantly, the magnetization reversal process of a similar three step-like film was simulated by the micromagnetics simulation, and the magnetic moment distribution of the thicker step presents a vortex state during the magnetization reversal process. [ABSTRACT FROM AUTHOR]

Achieving the broad effective absorption bandwidth (EAB), strong absorption capacity and thin matching thickness are still a huge challenge for the dielectric loss-type microwave absorbers. Here, the honeycomb-like SnS 2 / graphene oxide (GO) composites are fabricated via a facile chemical bath deposition method to optimize the microwave absorption performances. The 2D SnS 2 nanosheets are uniformly and vertically grown on the GO sheets, forming a highly open hierarchical network, which can be beneficial to enhance the multiple scatterings and reflections of incident electromagnetic wave. Meanwhile, the impedance matching (Z) and attenuation constant (α) of composites are well-tuned by changing the SnS 2 content in the composites. When the GO sheets are just completely coated by SnS 2 nanosheets, the SnS 2 /GO composite exhibits excellent microwave absorption ability with the minimum reflection loss (RL min) of − 59.2 dB and EAB of 5.4 GHz (12.3–17.7 GHz) at the thickness of only 1.45 mm, which is mainly ascribed to the strong interfacial polarization and good impedance matching. This work provides a significant guidance to achieve excellent absorption performance with broad EAB and strong absorption for dielectric loss-type absorbers. [Display omitted] • Honeycomb-like SnS 2 /GO composites are fabricated via chemical bath deposition. • Abundant SnS 2 -GO interfaces are constructed, resulting in strong polarization. • Excellent EMW absorption performances are obtained by adjusting SnS 2 content. • The RL min and EAB of SG2 reach − 59.2 dB and 5.4 GHz at 1.45 mm, respectively. [ABSTRACT FROM AUTHOR]