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Attention is often viewed as a mental spotlight, which can be scaled like a zoom lens at specific spatial locations and features a center-surround gradient. Here, we demonstrate a neural signature of attention spotlight in signal transmission along the visual hierarchy. fMRI background connectivity analysis was performed between retinotopic V1 and downstream areas to characterize the spatial distribution of inter-areal interaction under two attentional states. We found that, compared to diffused attention, focal attention sharpened the spatial gradient in the strength of the background connectivity. Dynamic causal modeling analysis further revealed the effect of attention in both the feedback and feedforward connectivity between V1 and extrastriate cortex. In a context which induced a strong effect of crowding, the effect of attention in the background connectivity profile diminished. Our findings reveal a context-dependent attention prioritization in information transmission via modulating the recurrent processing across the early stages in human visual cortex. [ABSTRACT FROM AUTHOR]

As the demand for high-capacity battery materials continues to grow, the exploration of the interaction mechanisms between Li/Na/K atoms and electrode materials has gained tremendous attention. In this study, we introduce a descriptor (ɛɑ) aimed at efficiently identifying high-performance electrode materials, specifically from two-dimensional transition metal chalcogenides and C and N compounds (MXenes). Our density functional theory calculations disclose a robust linear relationship between this descriptor and the adsorption energy (Ead), represented as Ead = ɛɑ + b. The fitting parameters, ɛɑ and b, are individually linked to the inherent properties of the substrate and adsorbate. Explicitly, the descriptor ɛɑ represents the capacity of the electrode material to accommodate an extra electron, while the intercept b is determined by the ionization energy (EIP) of alkali atoms and the coupling energy (Ecp) between the cation to the negatively charged substrate. This finding serves as a practical guide for designing high-capacity battery materials and paves the way for future advancements in this field. [ABSTRACT FROM AUTHOR]

• Three new multidrug-resistant tuberculosis (MDR-TB)/ pre-extensive drug-resistant tuberculosis (pre-XDR-TB) regimens, five drugs for 9 months. • The first cohort of short-course regimens for MDR-TB in China. • Of 99 assessable participants, 92.9% had a favorable outcome. • Culture conversion was 82.5% at month 2 and 97.9% at month 6. • Majority of adverse effects were manageable and reversible. Long, ineffective, and toxic regimens hinder the treatment of patients with multidrug-resistant tuberculosis (MDR-TB) and pre-extensive drug-resistant tuberculosis (pre-XDR-TB). We conducted a multicenter cohort study to prospectively evaluate the safety and efficacy of three 9-month, all-oral, 5-drug regimens. Regimen A (bedaquiline [Bdq]+linezolid [Lzd]+moxifloxacin [Mfx]+cycloserine [Cs]+pyrazinamide [Pza]) and Regimen B (Lzd+Mfx+Cs+clofazimine [Cfz]+Pza) were used to treat MDR-TB patients (Groups A and B, respectively, assigned according to the patient's treatment preference), while Regimen C (Bdq+Lzd+Cs+Cfz+Pza) was used to treat pre-XDR-TB patients (Group C). The primary endpoint was the occurrence of an unfavorable outcome within 12 months of treatment completion, regardless of regimen. A total of 104 patients (34 in Group A, 46 in Group B, and 24 in Group C), with a median age of 35.5 (29.0-54.0) years, were included in the analysis population. At 12 months after treatment completion, five patients were deemed non-assessable. Of the remaining 99 participants, seven (7.1%) had an unfavorable outcome (including two deaths from any cause, four with treatment failure, and one loss to follow-up) and 92 (92.9%) had a favorable outcome. Culture conversion was achieved in 82.5% (80/97) of participants at month 2 and in 97.9% (94/97) of participants at month 6. Adverse events (AEs) resulting in drug adjustment occurred in 69.2% (72/104) of participants, mainly due to Lzd and Pza use. A QT interval prolongation of ≥ 500 ms occurred in 5.8% (6/104) of participants. The primary outcome of the three tailored, 9-month, all-oral, 5-drug regimens was satisfactory in the vast majority of MDR-TB and pre-XDR-TB patients, with manageable and reversible AEs. [Display omitted] [ABSTRACT FROM AUTHOR]

Given the rapid developments in modern electronics, there is an urgent need for polymer composites with excellent heat‐dissipating capabilities to address the cooling problem of these devices. However, designing a highly thermally conductive polymer composite that can outperform metals and ceramics while also exhibiting high processability and low cost remains a challenge. Herein, inspired by the fibrous pathway of human nervous system, natural wood fibers (WFs) are used as the template and coated with graphene nanoplates (GNPs) via a simple electrostatic self‐assembly approach. Subsequent hot‐pressing process yields "core‐sheath" microstructured fibers, wherein the GNPs are compactly contacted face to face and arranged along the surfaces of the fibrous WF "cores". This WF@G biocomposite consists of highly efficient 3D fibrous "tracks" for heat transmission, resulting in an extremely high thermal conductivity of 134 W (m K)−1, which is at par with those of many metals. It also exhibits several other desirable properties and functionalities, including high mechanical strength and excellent flame resistance as well as remarkable electromagnetic shielding and Joule heating performances, which has significant potential for use as a functional thermal management material (TMM). Hence, this study describes a simple yet scalable manufacturing technique for the development of advanced metal‐level biomass‐based TMMs. [ABSTRACT FROM AUTHOR]

Background: Striatin interacting protein 2 (STRIP2) is a core component of the striatin-interacting phosphatase and kinase (STRIPAK) complexes, which is involved in tumor initiation and progression via the regulation of cell contractile and metastasis. However, the underlying molecular mechanisms of STRIP2 in non-small cell lung cancer (NSCLC) progression remain largely unknown. Methods: The expressions of STRIP2 and IGF2BP3 in human NSCLC specimens and NSCLC cell lines were detected using quantitative RT-PCR, western blotting, and immunohistochemistry (IHC) analyses. The roles and molecular mechanisms of STRIP2 in promoting NSCLC progression were investigated in vitro and in vivo. Results: Here, we found that STRIP2 expression was significantly elevated in NSCLC tissues and high STRIP2 expression was associated with a poor prognosis. Knockdown of STRIP2 suppressed tumor growth and metastasis in vitro and in vivo, while STRIP2 overexpression obtained the opposite effect. Mechanistically, P300/CBP-mediated H3K27 acetylation activation in the promoter of STRIP2 induced STRIP2 transcription, which interacted with insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) and upregulated IGF2BP3 transcription. In addition, STRIP2-IGF2BP3 axis stimulated m6A modification of TMBIM6 mRNA and enhanced TMBIM6 stability. Consequently, TMBIM6 involved NSCLC cell proliferation, migration and invasion dependent on STRIP2 and IGF2BP3. In NSCLC patients, high co-expression of STRIP2, IGF2BP3 and TMBIM6 was associated with poor outcomes. Conclusions: Our findings indicate that STRIP2 interacts with IGF2BP3 to regulate TMBIM6 mRNA stability in an m6A-dependent manner and may represent a potential prognostic biomarker and therapeutic target for NSCLC. [ABSTRACT FROM AUTHOR]

Megacheirans, or great‐appendage euarthropods, have featured prominently in discussions regarding the early evolution of the head region in total‐group Euarthropoda. However, several aspects of the ventral morphology of most representatives remain incompletely known given the loss of data associated with fossil compression, coupled with the rarity of some of these taxa. Here, we describe the ventral aspect of head organization of the jianfengiid megacheiran Jianfengia multisegmentalis using micro computed‐tomography, and explore its evolutionary significance. The head consists of a pair of stalked eyes, a pair of great appendages, and four pairs of biramous appendages, all covered by a dorsal head shield. The rostral portion of the head bears a median projection, which we interpret as an anterior sclerite akin to that observed in several other Cambrian euarthropods. The anterior sclerite in J. multisegmentalis articulates with robust stalks with rounded projections in a more adaxial position, and bears the compound eyes. Critically, the ventral side of the head of J. multisegmentalis features a prominent lobe‐shaped hypostome/labrum complex located immediately behind the great appendages, and between the first pair of biramous appendages. This situation is consistent with that observed in Leanchoilia illecebrosa and suggests a conserved, and possibly ancestral, pattern of a six‐segmented head (eyes, great appendages and four biramous limb appendages) with a hypostome/labrum complex for Megacheira. The existence of the hypostome/labrum complex in J. multisegmentalis falsifies the hypothesis that the anterior projections on the head of jianfengiids might be homologues of the euarthropod labrum. [ABSTRACT FROM AUTHOR]

Erythrokeratodermia variabilis et progressiva (EKVP) is a rare genodermatosis of clinical and genetic heterogeneity, characterized by the manifestations of localized or disseminated persistent hyperkeratotic plagues and stationary to migratory transient erythematous patches. The majority of EKVP cases display an autosomal dominant mode of inheritance with incomplete penetrance, although recessive transmission has also been described. Mutations associated with EKVP have been primarily detected in connexin (Cx) genes. We herein reported a Chinese sporadic case of late‐onset EKVP with a novel heterozygous missense mutation c.109G>A (p.V37M) in GJB4 (Cx30.3) gene, which resulted in a significant reduction of GJB4 expression in the epidermis of the patient. In accordance, while wild‐type GJB4 localized at the cell membrane of HeLa cells forming intercellular junctions and intracellular puncta, V37M mutant variant was diffusely expressed within HeLa cells at a considerably lower level. Our findings reveal an essential role of GJB4 in the pathogenesis of EKVP and provides insights into the therapeutic potential of the disease. [ABSTRACT FROM AUTHOR]

Modulating the surface electronic properties of the 2D MXenes is of significant importance to boost their hydrogen evolution reaction (HER) activity. Herein, a series of transition metal adatoms are employed to tune the surface electronic properties of Cr-based MXenes with oxygen function group for realizing impressive HER performance. The Results show that the charge of surface oxygen atoms, which is affected by both the host metal atoms and the adsorbed transition metal atoms, play critical role in the adsorption strength of hydrogen. The optimal performance is achieved by depositing Cr atom on the Cr 2 TiC 2 O 2 MXene, which results in the adsorption free energy of hydrogen very close to zero (0.03 eV). Systematic electronic structure analyses confirm that the charge transfer from the adsorbed transition metals to the neighboring surface oxygen atoms could tune the orbital occupancy of oxygen and their adsorption strength to hydrogen atom and therefore the HER activity. These findings and concepts may be useful for the design of advanced MXene-based HER catalysts. [Display omitted] • The pristine O-terminated MXenes are generally inert for hydrogen evolution reaction. • The adsorbed metals will lose electrons and shift the p-band center of MXenes downward. • The hydrogen evolution reaction activity is improved by transition metal adsorption. • This study highlight the potential applications of MXenes as electrocatalysts. [ABSTRACT FROM AUTHOR]

Summary: Based on the favorable neutronic performance, T/H (thermal‐hydraulic) characteristics and inherent safety of the lead‐cooled fast reactor (LFR), University of Science and Technology of China performed a preliminary design of the 1000Mth medium‐power modular lead‐cooled fast reactor M2LFR‐1000. To solve the core optimization problem of M2LFR‐1000, an automatic core design code named CODOPT (core design and optimization) was developed, considering geometry, neutronics and thermal‐hydraulics. CODOPT starts from setting a number of the core design schemes, then evaluates their key neutronic and T/H characteristics automatically and finally finds the design schemes satisfying the design constraints. Using this code, the sensitivity analysis of the key design parameters (fuel rod diameter, pitch diameter ratio, and inlet coolant velocity) is carried out. Under the neutronic and T/H design constraints, the optimization problem of the core has been studied using a multi‐objective function, which tries to find an optimal design with larger Keff, flatter power distribution, and minimum temperature of cladding and pellet. Current results show that the overall neutronic and T/H performance of M2LFR‐1000 can be improved by choosing the design parameters presented in this paper. The automatic core design ideas adopted currently can also provide some reference for future LFR designs. [ABSTRACT FROM AUTHOR]

This article uses a software architecture model that combines two architectures, based on the traditional Android environment. Through comparative research on network technology today, Java technology has been selected as a tool for developing network education systems for future research and maintenance upgrades. The underlying network education technology relies on APP to enable education between teachers and students. This technology can not only give play to the advantages of computers in network data transmission, but also embody a new teaching model with teachers and students as the main body. It can solve various practical problems in teacher and student education and educate teachers and students by simulating the actual educational environment of the classroom and educational process using a variety of practical education management strategies. The experimental results prove that with the help of this virtual classroom platform for ideological and political education, it can provide students with more ideological and political learning resources, increase students' interest and time in learning, and promote the diversification of ideological and political learning methods. The quality of teaching is more conducive to the learning of knowledge points for students. At the same time, the system is operating in good condition. Switching between different interfaces is maintained at about 0.1 seconds. The system performance is also perfect. The overall analysis function is basically designed. It is a better learning platform. [ABSTRACT FROM AUTHOR]

Catalytic properties of the 2D material Nb 2 CO 2 (MXene) with a surface oxygen vacancy and a supported single Pd atom in it (Pd/O V -Nb 2 CO 2) is explored using DFT calculations. It is found that the single Pd atom can be stably anchored in the oxygen vacancy and out of three mechanisms for carbon monoxide oxidation were studied for our model catalyst and one of them shows promising features, namely CO oxidation via a tri-molecular Eley–Rideal (TER) mechanism which has a small activation barrier of 0.42 eV. This result may provide some guidance for the selection of anode materials with high CO-tolerance and high efficiency in removing CO from H 2 for PEMFCs. Image 1 • Pd/O V -Nb 2 CO 2 can effectively capture CO from hydrogen fuel. • The presence of CO promotes the adsorption of O 2 on Pd/O V -Nb 2 CO 2. • Tri-molecular Eley-Rideal (TER) mechanism is preferential for CO oxidation. [ABSTRACT FROM AUTHOR]

Considering the various uncertainties in the implementation process of high-end equipment development tasks, the Monte Carlo simulation method is used to simulate the execution process of these tasks. Parameters such as the average duration and cost of the simulation output are used to evaluate the fitness of individuals, and consequently, the development process is optimized using the NSGA-III algorithm. By comparing the optimization results of the development task process under different quantities of resources, the impact of the quantity of resources on the optimization results of the development task process is analyzed. With a view to obtain a more satisfactory development task process, the PSO algorithm is nested into NSGA-III. The Pareto front solution set is obtained from the optimization of the task process. The PSO algorithm is applied to optimize the resource allocation for the development task process. Joint optimization of the high-end equipment development task process and resource allocation is carried out. Finally, the effectiveness of the proposed method is verified by an example. [ABSTRACT FROM AUTHOR]

Background: Several genetic driver alterations have been identified in micropapillary lung adenocarcinoma (MPA). However, the frequency of co-alteration of ROS1, EGFR, and EML4-ALK is yet unclear. Herein, we investigated the relationship between clinicopathologic characteristics and well-identified driver mutations of MPA compared with non-micropapillary lung adenocarcinoma (LA). Methods: Formalin-fixed paraffin-embedded (FFPE) sections derived from lung adenocarcinoma patients who never received adjuvant chemotherapy or radiation therapy prior to surgical resection were collected from October 2016 to June 2019. EGFR mutations, ROS1 rearrangements, and EML4-ALK fusion were identified in a set of 131 MPA and LA cases by using the amplification refractory mutation system (ARMS). The response rate and duration of response were assessed using Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1). Results: EGFR mutations had occurred in 42 (76.4%) MPA patients and 42 (55.3%) LA patients. Interestingly, ROS1 rearrangements were highly enriched only in the MPA cases (6/55, 10.9%) but rarely in the LA cases (1/76, 1.3%). Furthermore, 7.3% (4/55) MPA samples had double gene mutations, while only 1.3% (1/76) LA cases had double gene alterations. Of 5 patients with harboring two driver oncogene mutations, four patients (80%) obtained partial response, and one patient (20%) suffered recurrence. Conclusions: A higher prevalence of ROS1 rearrangement or combined mutations of ROS1, EGFR, and EML4-ALK may play a critical role in the tumorigenesis of MPA. These findings provide a novel therapeutic strategy for patients with malignant MPA through combining TKIs than one TKI. [ABSTRACT FROM AUTHOR]

The East Asian Monsoon (EAM) is a regional factor affecting the East Asian climate and the oceanographic processes of the marginal seas along the Western Pacific. Finding proxies for the EAM intensity and reconstructing the interannual and interdecadal variations of the EAM using high-resolution records are necessary to improve our understanding of the EAM's role in the global climate system and for predicting climate change. In this paper, high-resolution sedimentary records of sedimentary core C0702 obtained from the inner continental shelf of the East China Sea were comprehensively analyzed using a laser particle size analyzer, an ItraxTM core scanner, and a 210Pb and 137Cs radionuclide analyzer to explore potential proxies for the East Asian Winter Monsoon (EAWM). By combining the obtained results with instrumental observations of the EAM, we established a quantitative formula for the EAWM, which enables to reconstruct the evolution trend of the EAWM during the past 130 years. The sensitive grain-size component F2, with a grain-size range of 14.35–230 µm, and principal component PC1 of the sedimentary deposits of the East China Sea inner shelf can be used as EAWM proxies. The evolution of EAWM in 1880–1950 could be roughly divided into two stages: a weak EAWM period from 1882 to 1900 and a strong EAWM period from 1900 to 1945. This study improves our understanding of the variations in the EAWM on interannual and interdecadal temporal scales. [ABSTRACT FROM AUTHOR]

Synthesis of Ni and nitrogen-codoped carbon nanosheets by pyrolyzing citric acid and melamine at 900 °C. Single-atom catalysts have attracted wide attention recently because of their unique size quantum effect and superior atom utilization in CO 2 reduction reaction (CO 2 RR). Here, ultrathin Ni and nitrogen-codoped carbon nanosheets (Ni- N -CNSs) were proposed by a facile in-situ pyrolytic strategy. The ultrathin porous structure of Ni- N -CNSs affords large surface area, rich mesoporous volume and vast uniformly dispersed Ni atoms. The optimized catalyst exhibits a high CO Faradaic efficiency of nearly 100%, partial current density of 121.4 mA mg−1, CO production rate of 37.7 μmol mg−1 min−1, and super durability. In addition, the first principles calculations and the Mulliken charge analyses reveal the Ni sites show high bonding force towards the CO 2 molecules, which gives rise to the high activity and selectivity of Ni- N -CNSs in CO 2 RR. [ABSTRACT FROM AUTHOR]

Summary: The lead‐cooled fast reactor (LFR) offers enhanced safety and reliability with the fine properties of liquid lead and lead alloy. To study accurately the thermal characteristics of fast reactors, the multiscale thermal‐hydraulic coupling simulation is an effective way. Multiscale coupling based on the sub‐channel code has evident advantages on the analysis of fuel assemblies. In this study, a multiscale thermal‐hydraulic analysis of a forced‐circulation, medium‐power LFR under steady‐state and transient conditions is performed with the system code ATHLET and sub‐channel code KMC‐SUBtraC which was developed based on the previous version by modifying the pressure drop correlations and adding the assembly‐level calculation. The codes are one‐way‐coupled, with good efficiency and precision. Transient verification of the sub‐channel code is conducted with the CFD code. In the steady‐state analysis of M2LFR‐1000, mass flow and temperature distributions of the assemblies, sub‐channels, and fuel rods in the hottest assembly are analyzed and the safety performance is investigated. In the transient analysis, two typical DECs (unprotected overpower transient and ULOF+ULOHS) are simulated and the multiscale thermal‐hydraulic characteristics are analyzed. With the negative reactivity feedback, the variations of the temperatures of the coolant and fuel rods are within the safe limits, which shows the inherent safety of the reactor. And the results indicate that the loss of primary flow could increase the risk of cladding corrosion. [ABSTRACT FROM AUTHOR]

Previous studies of the reaction have mainly focused on providing the best central value and error bar for the S factor at solar energies. Experimental measurements of this capture reaction at higher energies, the – scattering phase shifts, as well as properties of and its excited state, have been used to constrain the theoretical models employed for this purpose. Here we show that much more information than was previously appreciated can be extracted from angle-integrated capture data alone. We use the next-to-leading-order (NLO) amplitude in an effective field theory (EFT) for to perform the extrapolation. At this order the EFT describes the capture process using an s-wave scattering length and effective range, the asymptotic properties of and its excited state, and short-distance contributions to the E1 capture amplitude. We extract the multi-dimensional posterior of all these parameters via a Bayesian analysis that uses capture data below 2 MeV. We find that properties of the ground and excited states are well constrained. The total S factor keV b, while the branching ratio for excited- to ground-state capture at zero energy, , both at 68% degree of belief. This S(0) is broadly consistent with other recent evaluations, and agrees with the previously recommended value b, but has a smaller error bar. We also find significant constraints on – scattering parameters, and we obtain constraints on the angular distribution of capture gamma rays, which is important for interpreting experiments. The path forward for this reaction seems to lie with better measurements of the scattering phase shifts and S(E)'s angular dependence away from zero energy, together with better understanding of the asymptotic normalization coefficients of the Be bound states' wave functions. Data on these could further reduce the uncertainty on S(0). [ABSTRACT FROM AUTHOR]

Distal-less homeobox 6 antisense RNA 1 (DLX6-AS1) is upregulated in various solid tumors and serves a critical role in the tumorigenesis of cancer. However, to the best of our knowledge, the expression of circulating DLX6-AS1 and its role in the diagnosis of non-small cell lung cancer (NSCLC) have not been previously clarified. The aim of the present study was to investigate the expression and clinical significance of circulating DLX6-AS1 using reverse transcription-quantitative PCR in serum and exosomes derived from patients with NSCLC and healthy donors. The diagnostic value of circulating DLX6-AS1 was identified by receiver operating characteristic curve (ROC) analysis. First, it was revealed that the expression levels of DLX6-AS1 were significantly increased in tumor tissues compared with in adjacent normal tissues. In addition, DLX6-AS1 was highly expressed in NSCLC cell lines compared with in BEAS-2B cells. DLX6-AS1-knockdown inhibited cell proliferation and migration in vitro. It was subsequently demonstrated that the serum DLX6-AS1 level was significantly higher in patients with NSCLC compared with in healthy controls. Additionally, the higher DLX6-AS1 expression was associated with advanced disease stage, positive lymph node metastasis and poor tumor differentiation of NSCLC. ROC analysis demonstrated that the sensitivity and specificity of DLX6-AS1 were higher than those of CYFRA21-1, which is a serum marker for NSCLC. Finally, exosomal DLX6-AS1 expression was increased in patients with NSCLC compared with in healthy controls. The present data implied that circulating DLX6-AS1 was mainly incorporated into exosomes, providing a novel potential diagnostic marker for NSCLC. [ABSTRACT FROM AUTHOR]

The development of efficient catalysts for low temperature CO oxidation is important to the application of fuel cells. In this work, we report that the Ag monolayer on WC (0001) surface (Ag ML /WC) could effectively catalyze CO oxidation through the L-H mechanism (CO + O 2 → OOCO → CO 2 + O). The most sluggish reaction step is suggested to be CO + O → CO 2 with a barrier of 0.48 eV, which is 1.21 eV lower than the barrier of O 2 dissociation. The electronic structure and d-band center analyses demonstrate that the promoted activity may originate from the synergistic effect between Ag monolayer and WC. The present study is conducive to design new efficient and cost-effective catalysts for CO oxidation without using of the noble platinum. • The AgML/WC (0001) has higher ability to adsorb small molecules compared to that of Ag (111). • The L-H and E-R mechanisms of CO oxidation on AgML/WC (0001) are comparatively studied. • The AgML/WC (0001) could effectively catalyze CO oxidation with higher activity than Pt (111). • The promoted activity may originate from the synergistic effect between AgML and WC. [ABSTRACT FROM AUTHOR]

Catalysts with fast NO oxidation kinetics and moderate adsorption towards NO 2 are urgently required for fast selective catalytic reduction of NO. Based on density functional calculations, we report in this work that Au monolayer on WC(0001) (Au/WC) has both high NO oxidation activity and strong adsorption to NO 2. The WC substrate shifts the d -band center of Au monolayer to the vicinity of the Fermi level and the binding strength of reactants on Au/WC is consequently enhanced. The rate constants of gas desorption obtained in this work are significantly lower than those of forward reactions, in accordance with previous molecule dynamics simulations. We anticipate that the present results will facilitate the development of high-performance catalysts for NO oxidation. Unlabelled Image • NO molecule will directly dissociate on pure WC(0001). • NO 2 will desorb easily from the Au(111). • Au/WC has a high activity towards NO oxidation and moderate adsorption to NO 2. • The synergistic effect between Au and WC endows the Au/WC a promising SCR catalyst. [ABSTRACT FROM AUTHOR]

Abstract H 2 dissociation barriers on Ag (111), Ag monolayer on WC (0001) (Ag ML /WC), Ag monolayer doped by Pt atom on WC (0001) (Ag ML Pt-d/WC) surface are decreasing from 1.07 to 0.03 eV. The ab initio atomistic thermodynamic data shows that at typical planar SOFC operating temperatures of 923–1073 K, under 100000-ppm pH 2 S/pH 2 , Ag ML Pt-d/WC can be sulfur free clean surface. Therefore, compared with traditional Nickel/Yttria-stabilized zirconia (Ni/YSZ) Solid Oxide Fuel Cells (SOFCs) anode, Ag ML Pt-d/WC shows high activity towards H 2 dissociation and high tolerance of sulfur poisoning. Graphical abstract Ag ML Pt-d/WC shows high activity towards H 2 dissociation and high tolerance of sulfur poisoning. Image 1 Highlights • A strategy to design an ideal sulfur tolerant anode material is proposed. • H 2 dissociation and sulfur adsorption on fours surfaces are presented. • Ag ML Pt-d/WC shows high activity towards H 2 dissociation. • Ag ML Pt-d/WC shows high tolerance towards sulfur poisoning. [ABSTRACT FROM AUTHOR]

Abstract The sustainable generation of H 2 from water electrolysis is a promising approach to alleviating current energy crisis and environmental pollution. However, the efficiency of such a system is limited by the conventional noble metal catalysts. Herein, using first-principle calculations, we demonstrate the potential of non-precious Co and N-codoped graphene systems (CoN x -N/O-gra, x = 1–4) in efficiently catalyzing the hydrogen evolution reaction (HER). The findings showed that the activity of the Co sites was influenced by the concentration and configuration of N dopants, as well as the coordination environment of Co atom. From the volcano curve, obtained by plotting the exchange current as a function of the adsorption free energy, optimal performance was achieved on CoN4-gra, which was attributed to the moderate adsorption of CoN4-gra towards H. The electronic structures analyses confirmed that the hybridization between Co sp orbital and H s orbital played key role in tuning the interactions between the catalysts and H, which could be regulated by the coordination environment of Co. The present findings highlight the potential of non-precious metal/non-metal-codoped graphene as HER catalysts and offers an effective approach to tune the HER activity by modifying the coordination environment of the metal atoms. Graphical abstract Image 1 Highlights • CoN4-gra possesses high performance for HER. • The HER activity could be manipulated by doping configuration and concentration. • The corrections play a critical role in HER performance. [ABSTRACT FROM AUTHOR]

The CO oxidation reaction over single-atom Pt catalyst dispersed on the defective TiC (1 0 0) surface with a Ti vacancy is studied using the dispersion-corrected density functional theory (DFT-D) computations. The stable configuration of the TiC supported single Pt atoms and the preferable CO oxidation reaction mechanisms are explored. The results demonstrate that the Pt atom may be tightly embedded in the surface Ti defect sites with a formation energy of −4.86 eV, forming a TiC supported single-atom platinum catalyst, marked as Pt@d-TiC. The adsorption characteristics of various adsorbates on Pt@d-TiC are investigated, and the Eley–Rideal (E–R) and Langmuir–Hinshelwood (L–H) mechanisms for CO oxidation on Pt@d-TiC are simulated. Specifically, it is found that all the reaction species prefer to be adsorbed on the TiC support, indicating that the support vigorously participates in the catalytic reactions. In addition, the catalytic CO oxidation reaction over Pt@d-TiC favors to start with the L–H reaction. The rate-limiting step is the formation of the peroxide-like (OCOO) intermediate complex by the coadsorbed CO and O 2 with an activation barrier of 0.91 eV. The subsequent E–R reaction has a lower energy barrier of 0.45 eV. This work clearly shows the catalytic activity of the single-atom Pt supported on TiC for CO oxidation and perhaps for other reactions. [ABSTRACT FROM AUTHOR]

Summary: Based on research and development experience from Gen III, Gen III+, and Gen IV reactor concepts, a 1000‐MWt medium‐power modular lead‐cooled fast reactor M2LFR‐1000 was developed by University of Science and Technology of China (USTC), aiming at achieving a reactor design fulfilling the Gen IV nuclear system requirements and meanwhile emphasizing application of optimization methods in preliminary design phase. By using the optimization methods presented, primarily considering the safety design limits (the maximum coolant velocity, the maximum cladding temperature, and the maximum burn‐up limited by the cladding radiation damage permitted), the preliminary design of 1000‐MWth medium‐power modular lead‐cooled fast reactor M2LFR‐1000 was carried out, including the design of fuel rods, fuel assemblies, reactivity control system, primary system, secondary system, decay heat removal system, and so on. The analysis of neutron characteristics (including reactivity feedback coefficients) and thermal hydraulics characteristics (the maximum fuel temperature and the maximum cladding outer surface temperature) of the core under normal steady‐state condition was carried out to evaluate the core design. Also, the analysis of 2 typical protected transients (protected transient over power accident and protected loss of flow accident) was conducted. Other analysis work of the reactor is to be done, such as the transient analysis via computational fluid dynamic codes and the seismic response analysis of the reactor. But the preliminary analysis results obtained so far under normal steady state and transient conditions confirm the inherent safety characteristics of the reactor design. [ABSTRACT FROM AUTHOR]

Feature-based attention has a spatially global effect, i.e., responses to stimuli that share features with an attended stimulus are enhanced not only at the attended location but throughout the visual field. However, how feature-based attention modulates cortical neural responses at unattended locations remains unclear. Here we used functional magnetic resonance imaging (fMRI) to examine this issue as human participants performed motion- (Experiment 1) and color- (Experiment 2) based attention tasks. Results indicated that, in both experiments, the respective visual processing areas (middle temporal area [MT+] for motion and V4 for color) as well as early visual, parietal, and prefrontal areas all showed the classic feature-based attention effect, with neural responses to the unattended stimulus significantly elevated when it shared the same feature with the attended stimulus. Effective connectivity analysis using dynamic causal modeling (DCM) showed that this spatially global effect in the respective visual processing areas (MT+ for motion and V4 for color), intraparietal sulcus (IPS), frontal eye field (FEF), medial frontal gyrus (mFG), and primary visual cortex (V1) was derived by feedback from the inferior frontal junction (IFJ). Complementary effective connectivity analysis using Granger causality modeling (GCM) confirmed that, in both experiments, the node with the highest outflow and netflow degree was IFJ, which was thus considered to be the source of the network. These results indicate a source for the spatially global effect of feature-based attention in the human prefrontal cortex. [ABSTRACT FROM AUTHOR]

The adsorption and dissociation of O 2 on the palladium and platinum modified TaC (1 0 0) surfaces were investigated based on the density functional theory calculations. It is found that the adsorption sites of O 2 are the Ta-Ta bridge sites on both the partially covered TaC (1 0 0) surfaces by Pd and Pt, M 4 /TaC (1 0 0) (M = Pd and Pt), while the 4-fold metal hollow sites and the metal-metal bridge sites are preferred on the fully covered TaC (1 0 0) surfaces by Pd and Pt monolayer, M ML /TaC (1 0 0), respectively. The deposition of Pd or Pt can enhance the oxidation resistance of TaC (1 0 0). Meanwhile, the TaC (1 0 0) decorated by monolayer Pd still exhibited outstanding catalytic activity for O 2 dissociation. Our study might be useful to designing efficient catalysts for the oxygen reduction reaction. [ABSTRACT FROM AUTHOR]

The bifunctional catalysts for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are of importance to the development of electrochemical energy systems such as reversible fuel cells, metal-air batteries, and water electrolyzers. Here, using the first-principles methods based on density functional theory (DFT), the Co and N codoped graphene systems (CoN x -gra, x = 1–4) with high ORR activity were further suggested as efficient OER catalysts. It was found that the activity on Co site of CoN x -gra towards ORR and OER would be affected by both the N-dopant concentration and configuration. The extrapolated overpotential of 0.37 V for either ORR or OER on CoN x -gra systems is comparable to those of noble metal benchmark catalysts. The origin of the activity stems from moderate hybridization between Co 3d orbital and p-orbital from O species, governed by the neighboring N coordination environment. Our results highlight the potential application of transition metal and non-metal codoped graphene as efficient non-precious bifunctional catalysts. [ABSTRACT FROM AUTHOR]

The supported catalysts have received great attentions due to their high catalytic activity, low cost and good stability. Here we report the stability, wetting ability, corrosion resistance and catalytic activity of the supported catalysts with group 9, 10 and 11 metals (M = Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au) monolayers (ML) deposited on NbC(001), denoted as M ML /NbC(001). The Pd ML /NbC(001) and Pt ML /NbC(001) are testified as the most stable and active ones with the former even better on the whole. The catalytic activities toward oxygen reduction reactions (ORR) are clarified by the dissociation and the change in Gibbs free energies for the elementary reaction steps of O 2 on Pd ML /NbC(001). [ABSTRACT FROM AUTHOR]

The sedimentary rhythm is well developed in the environment which is controlled by strong seasonal climate changing condition. This rhythm is important for sediment core dating purpose. In this study, we examine muddy sediments on the inner continental shelf of the East China Sea that are influenced under seasonal change of the East Asian monsoon. We use Ensemble Empirical Mode Decomposition (EEMD) method to process sediment grain size and X-radiograph negatives grayscale value data in three sediment cores from this area and use the results to analyze the patterns of sedimentary variability and the causes of cyclic variability of the sedimentary process. The variability in the grain size and grayscale values of the core sediments has three components: the high-frequency variability, low-frequency variability and a secular trend. Among these components, the high-frequency component reflects variability on annual time scale can be well recognized, we suggest that the annual variability is derived from seasonal variation in the sediment flux from the Yangtze River to the sea, as well as the East Asian monsoon's impact on the sedimentary dynamics of the East China Sea's inner continental shelf. However, the other variability is hard to identify which cycles there are. This variability may reflect decadal winter monsoon oscillation and human activity of dam construction in the Yangtze River. Each annual variability presents a varve in the sediment sequence, which can be used to determine the sediment deposition rate and accurately date the core sediment. We found that the average deposition rates of the three cores from north to south on the inner shelf were 3.1 cm/yr, 1.0 cm/yr, 0.9 cm/yr, indicating that the Yangtze-derived sediment decreased with the increasing distance from the Yangtze estuary to the shelf. The deposition rate of each core varies over time, and the maximum deposition rate can be 3–5 times greater than the minimum rate. The sediment ages obtained from varve chronology and radiometric dating are fairly consistent on a centennial scale, differing only by 2–5 years. Thus, varve counting is a useful supplementary approach to radiometric age dating for constructing chronologies for core sediment in shelf seas influenced by monsoons. [ABSTRACT FROM AUTHOR]

Classic theories of object-based attention assume a single object of selection but real-world tasks, such as driving a car, often require attending to multiple objects simultaneously. However, whether object-based attention can operate on more than one object at a time remains unexplored. Here, we used functional magnetic resonance imaging (fMRI) to address this question as human participants performed object-based attention tasks that required simultaneous attention to two objects differing in either their features or locations. Simultaneous attention to two objects differing in features (face and house) did not show significantly different responses in the fusiform face area (FFA) or parahippocampal place area (PPA), respectively, compared to attending a single object (face or house), but did enhance the response in the inferior frontal gyrus (IFG). Simultaneous attention to two circular arcs differing in locations did not show significantly different responses in the primary visual cortex (V1) compared to attending a single circular arc, but did enhance the response in the intraparietal sulcus (IPS). These results suggest that object-based attention can simultaneously select at least two objects differing in their features or locations, processes mediated by the frontal and parietal cortex, respectively. [ABSTRACT FROM AUTHOR]

Recently the experimentalists in Krasznahorkay (2016) [1] announced observing an unexpected enhancement of the e + – e − pair production signal in one of the 8 Be nuclear transitions. The subsequent studies have been focused on possible explanations based on introducing new types of particle. In this work, we improve the nuclear physics modeling of the reaction by studying the pair emission anisotropy and the interferences between different multipoles in an effective field theory inspired framework, and examine their possible relevance to the anomaly. The connection between the previously measured on-shell photon production and the pair production in the same nuclear transitions is established. These improvements, absent in the original experimental analysis, should be included in extracting new particle's properties from the experiment of this type. However, the improvements can not explain the anomaly. We then explore the nuclear transition form factor as a possible origin of the anomaly, and find the required form factor to be unrealistic for the 8 Be nucleus. The reduction of the anomaly's significance by simply rescaling our predicted event count is also investigated. [ABSTRACT FROM AUTHOR]

Carbon monoxide (CO) oxidation is an efficient way to purify CO. Herein, the geometrical properties, electronic structure and CO oxidation catalytic activity of Zn single atom catalyst (SAC) on pristine Ti 2 CT 2 (T = N/O/F) MXenes and defective ones (T v /Ti 2 CT 2) with a functional-group vacancy (T v) were calculated by using density functional theory (DFT) calculations. The results revealed that Ti 2 CN 2 may serve as an excellent substrate to stabilize single Zn atom catalyst, compared to Ti 2 CT 2 (T = O/F) and T v /Ti 2 CN 2 (T = N/O/F). The catalytic oxidation mechanism of CO on the surface of Zn–Ti 2 CN 2 has been systematically studied. The Eley–Rideal (ER) mechanism was identified as the most preferential pathway with the smallest rate-determining energy barrier of 0.06 eV, since the Zn atom can considerably promote the activation of O 2 molecule and weaken the O–O bond. Electronic structure analysis confirmed the synergistic effects of adsorbed single Zn atom and substrate in regulating electron transfer, activating the adsorbed small molecule reactants and enhancing CO oxidation activity. Overall, this work reveals that Zn–Ti 2 CN 2 could be a promising low-temperature CO oxidation candidate and probably provides a new theoretical guidance and inspiration for the experimental and theoretical research to design more effective single atom catalysts with nonprecious metals. [Display omitted] • The pristine Ti 2 CN 2 MXene serves as an excellent support of the transition metal Zn atoms. • The Zn-SACs supported on pristine Ti 2 CN 2 show high catalytic activity for CO oxidation. • The Zn–Ti 2 CN 2 can capture, activate O 2 molecule and weaken the O–O bond. • This study highlights the potential applications of Zn-SACs as catalysts. [ABSTRACT FROM AUTHOR]

The development of perovskite solar cells has improved rapidly. However, PSCs generally suffer from instability, due to the detrimental defects. Additive engineering is a favorable method for defect passivation. In this work, the linear pseudo-halogen salt, KSCN, is introduced into the MAPbI 3 perovskite film to improve the performance of PSC. The trap density of cells with SCN− is decreased significantly. The SCN− not only can fill halogen vacancies to reduce the halide-related defects, but also can interact with the uncoordinated Pb2+ via coordinate bond to stabilize perovskite lattice structure. Moreover, the performance of devices with other linear pseudo-halogen anions (OCN−, SeCN−) are also investigated. Due to the improved short circuit current density, the power conversion efficiency of devices increases from 18.02% (PVK) to 20.41% (PVK–SCN-), 19.53% (PVK–OCN-) and 19.23% (PVK–SeCN-), respectively. After introducing pseudo-halide anions, the devices showed robust stability under the ambient environment. [ABSTRACT FROM AUTHOR]

Highly active, durable, and cost‐effective electrodes for hydrogen evolution reaction (HER) at ultrahigh current densities (≥1 A cm−2) are extremely demanded for industrial high‐rate hydrogen production, but challenging. Here, a robust strongly coupled Ag(S)@NiO/nickel foam (NF) electrode is reported. Taking advantage of millisecond laser direct writing in liquid nitrogen technique, lattice‐matched and coherent interfaces are formed between Ag nanoparticles with stacking faults (denoted by Ag(S)) and NiO nanosheets, leading to strong interfacial electronic coupling, not only promoting H2O adsorption and dissociation on Ni2+ but also enhancing H* adsorption on intrinsically inactive but most electrically conductive Ag. Strong chemical bonding is established at NiO/NF interface, guaranteeing rapid electron transfer and excellent mechanical durability under high‐rate hydrogen evolution. The physicochemically stable electrode achieves record‐low alkaline HER overpotential of 167 and 180 mV at 1 and 1.5 A cm−2, respectively, along with negligible activity decay after 120 h test at ≈1.5 A cm−2, surpassing reported non‐platinum group metal electrocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Defective PtX 2 (X = S, Se, Te) is an excellent structure for supporting Pt atom. • Pt 1 /PtTe 2 has high catalytic activity for CO oxidation. • The electronegativity of X atoms changes the O 2 capture ability of the substrate. • Defective monolayer TMDs can serve as excellent substrates for SACs. The geometric stability, electronic structure and catalytic properties towards CO oxidation of a single Pt atom supported on PtS 2 , PtSe 2 , PtTe 2 with a S, Se, and Te vacancies (Pt 1 /PtX 2) were systematically explored by density functional theory calculations. The results showed that the single Pt atom can be located at the vacancy site stably, providing accessible active sites for CO oxidation. Both the Langmuir-Hinshelwood (LH) mechanism and the termolecular Eley-Rideal (TER) mechanism were considered comprehensively. By comparing the rate-determining step (RDS) of CO oxidation process, we found that the LH mechanism is easier to achieve. Meanwhile, as the X atom changes from S to Te, the RDS energy barrier gradually decreases, which is attributed to promoted adsorption and activation of O 2 molecules on Pt 1 /PtX 2. The results show that Pt 1 /PtTe 2 is the most active catalysts with a low RDS barrier of 0.41 eV. This work provides an important reference for the design of single atom catalysts (SACs) based on transition metal dichalcogenides (TMDs), and has profound implications for the use of supported SACs on defective TMDs for CO oxidation or other reactions. [ABSTRACT FROM AUTHOR]

• The multiple functions of axial oxygen ligand in improving ORR activity were exploited. • The axial oxygen ligand may participate in the catalysis. • The homolateral adsorbate evolution mechanism is preferential for oxygen reduction. • The dynamically wobbly oxygen will modulate the orbital orientation of metal atom. The catalytic activity of single metal atom were effectively enhanced by different coordination environments, and the underlying improvement mechanisms are generally ascribed to the electronic structure modification by in-plane ligands. Herein, taking the recently synthesized MoNO composites modified carbon as representative, we clarified the multiple functions of axial oxygen ligand in improving the oxygen reduction activity. The active Mo atom is protruded from graphene plane due to the interaction with axial oxygen ligand, and during adsorption of oxygenates, the hanging oxygen ligand would wag to leave space and meanwhile tune the orbital orientation of Mo atom, giving rise to an optimal adsorption strength on the side in presence of oxygen ligand. The dynamic oxygen ligand may participate in the catalysis through hydrogenation reaction at the coadsorption stage with oxygen intermediate. The obtained overpotential of 0.35 V on MoN 2 O 1 -pen-gra along homolateral adsorbate evolution mechanism is comparable to recent experiments, approving the reliability of models and mechanism proposed in current study. The present results could provide some new insights into the functions of axial ligands and further guide the rational design of axial coordination to improve the catalytic performance. Graphical Abstract: [Display omitted] [ABSTRACT FROM AUTHOR]

The deposition of platinum on the tungsten carbide (Pt/WC) have been achieved and proved with high stability, activity and CO-tolerance toward some reactions in experiments. Although a lot of experimental efforts have been focused on understanding the activity, stability and CO-tolerance of Pt/WC, the relevant theoretical works related to the CO-tolerance mechanism are still scarce. In current study, the adsorption and oxidation of CO on the Pt monolayer supported on WC(0001) surface (Pt ML /WC(0001)) are investigated using density functional theory calculations. It is found that the oxidation of CO on Pt ML /WC(0001) proceeds preferably along the Langmuir-Hinshelwood mechanism. The energy barrier of 1.06 eV for the rate-determining step of OOCO formation is almost equal to that (1.05 eV) for CO oxidation by atomic O on Pt(111), while the adsorption energy of 1.59 eV for CO on Pt ML /WC(0001) is smaller than that on Pt(111) (1.85 eV), indicating that the high resistance to CO poisoning of Pt ML /WC(0001) may originate from the weak interaction between them. To further improve the CO tolerance, some probable strategies are proposed based on the relevant kinetics results. The current results are helpful to understanding the origin of the highly resistant to CO poisoning of Pt ML /WC(0001) and rationally designing catalysts to improve the CO oxidation activity. [ABSTRACT FROM AUTHOR]

The kinetic activation barriers and the thermodynamic free energy changes for the probable elementary reaction steps of oxygen reduction reaction (ORR) are calculated by the first principles methods to clarify the debate whether the 2e − or 4e − pathway dominates the ORR on the CoN 4 embedded graphene (CoN 4 -gra). It is found that the CoN 4 -gra can promote the ORR to proceed along a 4e − pathway and to finally generate two H 2 O by successive hydrogenation reactions. The reduction of OOH into O and H 2 O with the largest barrier of 0.69 eV is suggested to be the kinetic rate-determining step (RDS). The thermodynamics results show that the elementary steps of ORR along the 4e − pathway are downhill at the electrode potential lower than 0.58 V. The last step, the reduction of OH into H 2 O with the largest ΔG value (−0.58 eV), functions as the thermodynamic RDS of the 4e − pathway. The large/small energy barriers and small/large thermodynamic driving forces for the generation/dissociation of HOOH indicate also that the 2e − pathway is less favorable than the 4e − pathway for ORR on CoN 4 -gra. [ABSTRACT FROM AUTHOR]

The normalization model of attention proposes that attention can affect performance by response- or contrast-gain changes, depending on the size of the stimulus and attention field. Here, we manipulated the attention field by emotional valence, negative faces versus positive faces, while holding stimulus size constant in a spatial cueing task. We observed changes in the cueing effect consonant with changes in response gain for negative faces and contrast gain for positive faces. Neuroimaging experiments confirmed that subjects’ attention fields were narrowed for negative faces and broadened for positive faces. Importantly, across subjects, the self-reported emotional strength of negative faces and positive faces correlated, respectively, both with response- and contrast-gain changes and with primary visual cortex (V1) narrowed and broadened attention fields. Effective connectivity analysis showed that the emotional valence-dependent attention field was closely associated with feedback from the dorsolateral prefrontal cortex (DLPFC) to V1. These findings indicate a crucial involvement of DLPFC in the normalization processes of emotional attention. [ABSTRACT FROM AUTHOR]

Apolipoprotein E (apoE) is a major cholesterol carrier that regulates lipid homeostasis by mediating lipid transport from one tissue or cell type to another. In the central neural system (CNS), apoE is mainly produced by astrocytes, and transports cholesterol to neurons via apoE receptors, which are members of the low-density lipoprotein receptor family. The APOEε4 gene is a strong genetic risk factor for late-onset sporadic Alzheimer's disease (AD), likely through its strong effect on the accumulation of amyloid-β (Aβ) peptide. ApoE protein levels in cerebrospinal fluid (CSF) and plasma are reduced in APOEε4 carriers and in patients with AD. Furthermore, altered cholesterol levels are also associated with the risk of AD. Aβ accumulation, oligomerization and deposition in the brain are central to the pathogenesis of AD. Mounting evidence demonstrates that apoE and apoE receptors play important roles in these processes. Astrocyte-derived apoE is pivotal for cerebral cholesterol metabolism and clearance of Aβ. Thus, we hypothesized that increased apoE in the brain may be an effective therapeutic strategy for AD. We report here that quercetin can significantly increase apoE levels by inhibiting apoE degradation in immortalized astrocytes. Importantly, we show that oral administration of quercetin significantly increased brain apoE and reduced insoluble Aβ levels in the cortex of 5xFAD amyloid model mice. Our results demonstrate that quercetin increases apoE levels through a novel mechanism and can be explored as a novel class of drug for AD therapy. [ABSTRACT FROM AUTHOR]

Using the first principles methods, the geometric and electronic structures of the metal monolayers supported on WC(0001) surfaces (M ML /WC(0001) (M = Pt, Pd, and Au)) and their catalytic activity toward the oxygen reduction reaction (ORR) were comparatively studied. Both the kinetics and the density of states results demonstrated that the direct dissociation of O 2 on all three M ML /WC(0001) surfaces are almost impossible. Yet the barriers of the formation and dissociation of OOH on Au ML /WC(0001) are much smaller than those on the Pt ML /WC(0001) and the Pd ML /WC(0001) surfaces, implying that the Au ML /WC(0001) exhibits the highest catalytic activity for ORR via a combination of 2e − hydrogenation of O 2 and 4e − dissociation of OOH. The rate-limiting step barrier of 0.83 eV for the hydrogenation of OH forming H 2 O is also comparable to that on the traditional Pt-based catalysts. The deactivation mechanism of Pt ML /WC(0001) and the performance of Pd ML /WC(0001) for ORR were identified. The present study is conductive to designing new efficient catalyst without using of the precious Pt for efficiently promoting ORR. [ABSTRACT FROM AUTHOR]

A saliency map is the bottom-up contribution to the deployment of exogenous attention. It, as well as its underlying neural mechanism, is hard to identify because of the influence of top-down signals. A recent study showed that neural activities in V1 could create a bottom-up saliency map (Zhang et al. in Neuron 73(1):183-192, ). In this paper, we tested whether their conclusion can generalize to complex natural scenes. In order to avoid top-down influences, each image was presented with a low contrast for only 50 ms and was followed by a high contrast mask, which rendered the whole image invisible to participants (confirmed by a forced-choice test). The Posner cueing paradigm was adopted to measure the spatial cueing effect (i.e., saliency) by an orientation discrimination task. A positive cueing effect was found, and the magnitude of the cueing effect was consistent with the saliency prediction of a computational saliency model. In a following fMRI experiment, we used the same masked natural scenes as stimuli and measured BOLD signals responding to the predicted salient region (relative to the background). We found that the BOLD signal in V1, but not in other cortical areas, could well predict the cueing effect. These results suggest that the bottom-up saliency map of natural scenes could be created in V1, providing further evidence for the V1 saliency theory (Li in Trends Cogn Sci 6(1):9-16, ). [ABSTRACT FROM AUTHOR]

The low operating temperature, high efficiency and noble-metal-free are the goal of the ideal catalysts. In present study, an efficient noble-metal-free catalyst for CO oxidation with a single cobalt atom incorporated with pyridinic nitrogen graphene (Co-N 3 -gra) is proposed. The catalytic activity for CO oxidation via various mechanisms on the Co-N 3 -gra catalyst is investigated using the first-principles method. It is found that the CO oxidation occurs preferably following the Langmuir-Hinshelwood mechanism (CO + O 2 → OOCO → CO 2 + O) with an energy barrier of 0.86 eV for the rate-limiting step of OOCO formation. Our findings prove that the activity of noble-metal-free Co-N 3 -gra catalyst is comparable to or even higher than some other single noble-metal-graphene based catalysts. [ABSTRACT FROM AUTHOR]

One of the central tasks for the visual system is to integrate visual features into objects, which is referred to as the binding problem. To study the binding mechanisms, it has been suggested to use phenomena of feature misbinding to separate active feature binding from feature co-occurence. Taking advantage of a steady-state misbinding of color and motion, we performed psychophysical and event-related potential (ERP) adaptation experiments to investigate the neural mechanisms of the misbinding (i.e., the active color-motion binding). Human subjects adapted to the misbinding of color and motion, as well as their correct binding that was used for identifying neural processes associated with the co-occurrence of color and motion. We found that adaptation to the misbinding and the correct binding could generate color-contingent motion aftereffects (CCMAEs), but in opposite directions. ERP adaptation effects manifested in the earliest ERP component C1. The C1 latency in the misbinding condition was 11ms longer than that in the correct binding condition. In the correct binding condition, the C1 adaptation effect (i.e., the C1 amplitude reduction after adaptation) took place in the peak phase of the C1. The dipole source of the adaptation effect was located in V1. In the misbinding condition, the C1 adaptation effect occurred in the descending phase of the C1 and its dipole source was in V2. In both conditions, the C1 adaptation effects correlated with the CCMAEs across individual subjects. These findings provide human electrophysiological evidence that active feature binding takes place in early visual cortex, but at later processing stages than feature co-occurrence. [ABSTRACT FROM AUTHOR]

The growth process of Pt monolayer on ZrC(100) were investigated using density functional theory calculations. The strong interaction of Pt atoms with ZrC(100) was beneficial to improving the stability and activity of Pt catalyst. The adsorption and dissociation of O 2 on the bare and Pt modified ZrC(100) were comparably investigated, and found that the supported Pt on ZrC(100) have a positive impact on promoting the scission of the O O bond and weakening the adsorption of produced O, which shed meaningful light on the important role of ZrC(100) as support to improve the efficiency of Pt for oxygen reduction. [ABSTRACT FROM AUTHOR]

We report an improved low-energy extrapolation of the cross section for the process Be 7 ( p , γ ) B 8 , which determines the 8 B neutrino flux from the Sun. Our extrapolant is derived from Halo Effective Field Theory (EFT) at next-to-leading order. We apply Bayesian methods to determine the EFT parameters and the low-energy S -factor, using measured cross sections and scattering lengths as inputs. Asymptotic normalization coefficients of 8 B are tightly constrained by existing radiative capture data, and contributions to the cross section beyond external direct capture are detected in the data at E < 0.5 MeV . Most importantly, the S -factor at zero energy is constrained to be S ( 0 ) = 21.3 ± 0.7 eV b , which is an uncertainty smaller by a factor of two than previously recommended. That recommendation was based on the full range for S ( 0 ) obtained among a discrete set of models judged to be reasonable. In contrast, Halo EFT subsumes all models into a controlled low-energy approximant, where they are characterized by nine parameters at next-to-leading order. These are fit to data, and marginalized over via Monte Carlo integration to produce the improved prediction for S ( E ) . [ABSTRACT FROM AUTHOR]

Air gun arrays are designed to generate strong energy pulses of less than 100 Hz for offshore oil and gas exploration. In shallow seas, due to the directivity of air gun arrays, the complex propagation conditions and the limitations of acquisition methods, it is difficult to accurately evaluate the spatial time and frequency transmission characteristics of airguns. To alleviate the existing lack of knowledge about the transmission characteristics of air gun pulses in the shallow waters of the Bohai Sea, we analysed three‐dimensional ocean bottom cable seismic data collected during a seismic survey in the Bohai Sea, China, in June 2017, which were used to evaluate the reception level, frequency domain characteristics and spatial distribution characteristics within a 5.55 × 5.575 km area. The results showed that in shallow water, multipath propagation causes downfrequency chirplike sounds and an increased sound field. Within 0.3 km, the transmission model follows a cylindrical diffusion, and the sound loss rate decreases as the transmission distance increases until reaching 8 km. Signal capture by the sound channel results in a high transmission loss frequency band, whereas multimode interference weakens the transmission loss. The gun array directivity and the transmission channel are the two main factors affecting the acoustic field. This research provides an improved understanding of the acoustic field of airguns in the Bohai Sea, which can benefit the acoustic modelling of air gun arrays, the design of future seismic exploration projects and the conservation of marine life. [ABSTRACT FROM AUTHOR]

We generalize forward real Compton amplitude to the case of the interference of the electromagnetic and weak neutral current, formulate a low-energy theorem, relate the new amplitudes to the interference structure functions and obtain a new set of sum rules. We address a possible new sum rule that relates the product of the axial charge and magnetic moment of the nucleon to the 0th moment of the structure function g 5 ( ν , 0 ) . For the dispersive γZ -box correction to the proton's weak charge, the application of the GDH sum rule allows us to reduce the uncertainty due to resonance contributions by a factor of two. The finite energy sum rule helps addressing the uncertainty in that calculation due to possible duality violations. [ABSTRACT FROM AUTHOR]

The mechanisms for oxygen reduction reaction (ORR) on the metal-free phosphorus doped graphene (P-Gra) support are investigated using the density function theory (DFT) calculations. It is found that all the ORR species can be strongly adsorbed on the P-Gra except for the H 2 O molecule. Our calculation results show that all of the possible ORR elementary reactions could take place within a small region around the dopant and the ORR could proceed firstly by a 2e − process to form an OOH intermediate, which is followed by the 4e − process to break the O–O bond of OOH. Along this reaction path, the reduction of the second OH to H 2 O is the rate-limiting step with the largest barrier of 0.88 eV. To the best of our knowledge, this is the first theoretical investigation on the mechanisms for the entire process of the ORR on the P-Gra. [ABSTRACT FROM AUTHOR]

Infl uences of large-scale climatic phenomena, such as the El Niño/La Niña-Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO), on the temporal variations of the annual water discharge at the Lijin station in the Huanghe (Yellow) River and at the Datong station in the Changjiang (Yangtze) River were examined. Using the empirical mode decomposition-maximum entropy spectral analysis (EMDMESA) method, the 2- to 3-year, 8- to 14-year, and 23-year cyclical variations of the annual water discharge at the two stations were discovered. Based on the analysis results, the hydrological time series on the interannual to interdecadal scales were constructed. The results indicate that from 1950 to 2011, a significant downward trend occurred in the natural annual water discharge in Huanghe River. However, the changes in water discharge in Changjiang River basin exhibited a slightly upward trend. It indicated that the changes in the river discharge in the Huanghe basin were driven primarily by precipitation. Other factors, such as the precipitation over the Changjiang River tributaries, ice melt and evaporation contributed much more to the increase in the Changjiang River basin. Especially, the impacts of the inter-annual and inter-decadal climate oscillations such as ENSO and PDO could change the long-term patterns of precipitation over the basins of the two major rivers. Generally, low amounts of basin-wide precipitation on interannual to interdecadal scales over the two rivers corresponded to most of the warm ENSO events and the warm phases of the PDO, and vice versa. The positive phases of the PDO and ENSO could lead to reduced precipitation and consequently affect the long-term scale water discharges at the two rivers. [ABSTRACT FROM AUTHOR]