Search

Spiking neural networks (SNNs) are known as third generation neural networks due to their energy efficient and low power consumption. SNNs have received a lot of attention due to their biological plausibility. SNNs are closer to the way biological neural systems work by simulating the transmission of information through discrete spiking signals between neurons. Influenced by the great potential shown by the attention mechanism in convolutional neural networks, Therefore, we propose a Spiking Attention Neural Network (Sa-SNN). The network includes a novel Spiking-Efficient Channel Attention (SECA) module that adopts a local cross-channel interaction strategy without dimensionality reduction, which can be achieved by one-dimensional convolution. It is implemented by convolution, which involves a small number of model parameters but provides a significant performance improvement for the network. The design of local inter-channel interactions through adaptive convolutional kernel sizes, rather than global dependencies, allows the network to focus more on the selection of important features, reduces the impact of redundant features, and improves the network's recognition and generalisation capabilities. To investigate the effect of this structure on the network, we conducted a series of experiments. Experimental results show that Sa-SNN can perform image classification tasks more accurately. Our network achieved 99.61%, 99.61%, 94.13%, and 99.63% on the MNIST, Fashion-MNIST, N-MNIST datasets, respectively, and Sa-SNN performed well in terms of accuracy compared with mainstream SNNs. [ABSTRACT FROM AUTHOR]

Background: Sodium-dependent glucose transporter 2 inhibitor (SGLT2i) has the advantages of effectively lowering blood glucose levels and improving renal outcomes in diabetic patients. This study evaluated the effect of canagliflozin on intrarenal lipid content and oxygenation in newly diagnosed type 2 diabetes mellitus (T2DM) patients. Methods: A total of 64 newly diagnosed T2DM patients with normal renal function were randomly divided into canagliflozin (n = 33) and glimepiride control (n = 31) groups. All patients underwent functional magnetic resonance imaging (fMRI) scanning to assay patients' intrarenal lipid content and oxygenation level before and after 24 weeks of treatment. Furthermore, the relationship between body mass index and intrarenal lipid content in T2DM patients was analyzed and the correlation between changes in intrarenal lipid content and improvements in renal hypoxia was further assessed. Results: The canagliflozin group had a greater decrease in body weight and blood uric acid level than the glimepiride group (all P < 0.05). The intrarenal lipid content could be significantly reduced after canagliflozin treatment for 24 weeks. The R2* values, a parameter for quantifying the oxygen content in tissues and is inversely related to the oxygen content, of the renal cortex and medulla in the canagliflozin group decreased from the baseline by 6.40% (P < 0.01) and 12.09% (P = 0.000007), respectively. In addition, the degree of reduction of fat fraction (ΔFF) in the kidneys of the canagliflozin group was correlated with the degree of improvement of oxygenation level (ΔR2*) in the renal cortex (r = 0.422, P = 0.014). Conclusions: The early renal protective effect of SGLT2i in newly diagnosed T2DM patients may be partly attributed to the amelioration of renal hypoxia via the alleviation of ectopic lipid deposition in the kidneys. Trial Registration: Chu Hsien-I Memorial Hospital of Tianjin Medical University (ChiCTR2000037951). [ABSTRACT FROM AUTHOR]

In recent years, the transformer model has been widely used in computer-vision tasks and has achieved impressive results. Unfortunately, these transformer-based models have the common drawback of having many parameters and a large memory footprint, causing them to be difficult to deploy on mobiles as lightweight convolutional neural networks. To address these issues, a Vision Transformer (ViT) model, named the lightweight Vision Transformer (LW-ViT) model, is proposed to reduce the complexity of the transformer-based model. The model is applied to offline handwritten Chinese character recognition. The design of the LW-ViT model is inspired by MobileViT. The lightweight ViT model reduces the number of parameters and FLOPs by reducing the number of transformer blocks and the MV2 layer based on the overall framework of the MobileViT model. The number of parameters and FLOPs for the LW-ViT model was 0.48 million and 0.22 G, respectively, and it ultimately achieved a high recognition accuracy of 95.8% on the dataset. Furthermore, compared to the MobileViT model, the number of parameters was reduced by 53.8%, and the FLOPs were reduced by 18.5%. The experimental results show that the LW-ViT model has a low number of parameters, proving the correctness and feasibility of the proposed model. [ABSTRACT FROM AUTHOR]

Mesoporous Pt-containing nanocomposites with well-organized pores are desirable for fuel cells as well as sensors, electronics, and various chemical reactions. However, it remains challenging to construct three-dimensional (3D) ordered honeycomb-like (OHC) nanostructures with Pt species anchored in the mesopores. Herein, we show for the first time an in situ strategy of developing an N-doped ordered honeycomb (N-OHC) nanopattern with well-dispersed Pt–N2 moieties by using the self-assembly of a block copolymer (BCP). The as-mentioned Pt including Pt single atoms (SAs) and Pt ∼2.5 nm ultrafine nanoparticles (NPs) was hierarchically located on the inner walls and the outer surfaces of the N-OHC mesopores (Pt/N-OHC), forming well-dispersed Pt–N active sites and showing efficient catalytic activity towards the oxygen reduction reaction (ORR). By changing the film thickness of the pristine Pt/BCP template, double-layered Pt/N-OHC could be designed and the ORR activity could be correspondingly improved, for which a current density of 1.60 A cm−2@0.6 V and a peak power density of 1.07 W cm−2 were observed at a very low Pt-loading of 0.04 mg cm−2, better than 1.21 A cm−2@0.6 V and 0.79 W cm−2 of the commercial Pt/C catalyst at a Pt-loading of 0.15 mg cm−2. The electron donating behavior of Pt–N2 and the pathway for O2 reduction were investigated via the density functional theory (DFT) computation. The electron transfer from Pt to N gave rise to the formation of Pt–N covalent bonds, which resulted in a lower d band center and a weaker O adsorption energy and endowed the Pt/N-OHCs with enhanced ORR activity. [ABSTRACT FROM AUTHOR]

Aims: To assess the prevalence of diabetes-associated autoantibodies in Chinese patients recently diagnosed with adult-onset diabetes and to evaluate the potential role of the autoantibody markers for characterization of disease phenotype in the patient population. Methods: The study included 1273 recent-onset adult patients with phenotypic type 2 diabetes mellitus (T2DM). Serum samples were tested using the 3-Screen ICA™ ELISA (3-Screen) designed for combined measurement of GADAb and/or IA-2Ab and/or ZnT8Ab. 3-Screen positive samples were then tested for individual diabetes-associated and other organ-specific autoantibodies. Clinical characteristics of patients positive and negative in 3-Screen were analysed. Results: Forty-four (3.5%) of the T2DM patients were positive in 3-Screen, and 38 (86%) of these were also positive for at least one of GADAb, IA-2Ab and ZnT8Ab in assays for the individual autoantibodies. 3-Screen positive patients had lower BMI, higher HbA1c, lower fasting insulin levels and lower fasting C-peptide levels compared to 3-Screen negative patients. Analysis using a homeostatic model assessment (HOMA2) indicated that HOMA2-β-cell function was significantly lower for the forty-four 3-Screen positive patients compared to 3-Screen negative patients. Twenty (45%) 3-Screen positive patients were also positive for at least one thyroid autoantibody. Conclusions: The 3-Screen ELISA has been used successfully for the first time in China to detect diabetes autoantibodies in patients with phenotypic T2DM. 3-Screen positive patients presented with poorer β cell function. [ABSTRACT FROM AUTHOR]

We present a facile approach for the direct attachment of cross-linked poly(2-thiopheneacetic acid) onto the surface of magnetite nanoparticles with one single carbon layer (Fe3O4@1C NPs) via self-assembly oxidative polymerization. The functional Fe3O4@1C NPs combined with poly(2-thiopheneacetic acid) [Fe3O4@1C@ poly(Th) NPs] was successfully prepared and used for magnetic solid-phase extraction (MSPE). The influence of the preparation conditions and extraction conditions were investigated in detail. The morphology and size distribution of the monolithic materials were characterized by transmission electron microscopy. Under the optimized experimental conditions, the prepared Fe3O4@1C@ poly(Th) NPs showed good extraction efficiency for canthin-6-one alkaloids. Furthermore, the results indicated that the binding specificity and selectivity of the Fe3O4@1C@ poly(Th) NPs might be attributed to electrostatic interactions and pore structure. A MSPE–HPLC method was also developed for quantitative analysis of canthin-6-one alkaloids. The developed method showed good linearity, low limit of detections, low limit of quantifications, and good reproducibility over a wide linear range. To further prove the utility, Fe3O4@1C@ poly(Th) NPs-MSPE was also used to extract canthin-6-one alkaloids from Eurycoma longifolia stems, with a recovery rate of 87.9–114%. Thus, this method is potentially applicable for the extraction of similar alkaloid compounds from medicinal herb samples. [ABSTRACT FROM AUTHOR]

The effects of different dietary protein and lipid levels on juvenile greenfin horse-faced filefish (Thamnaconus septentrionalis) was experimentally evaluated in a 56-day study. Fish (initial weight 6.47±0.56 g) were fed with nine different diet combinations containing three varying levels of protein (37%, 43%, 49%) and lipids (4%, 7%, 10%) in triplicates, where the protein-to-energy (P/E) ratios of the diets varied in the range of 19.17–26.99 mg kJ−1. Results showed that fish fed diets containing 49% protein and 10% lipid exhibited significantly lower feed intake than those fed other diets. The weight gain of fish fed diets with 43% protein was significantly higher than that of fish fed 37% or 49% protein diets. While no significant change in weight gain was observed when lipid content was increased from 4% to 7%, weight gain decreased significantly when lipid increased from 7% to 10%. The protein efficiency ratio and feed efficiency were highest when the fish were fed the diet with 49% protein and 7% lipids. Muscle crude lipid content was positively correlated with dietary protein level regardless of lipid level. The diet of 43% protein or 7% lipids significantly reduced the activity of alanine aminotransferase and aspartate aminotransferase in liver. The contents of aspartate aminotransferase, superoxide dismutase and malondialdehyde were significantly increased from 4% to 10% lipids in plasma. The plasma total cholesterol and triglyceride contents were positively correlated with dietary lipid level at the same protein level. Our comprehensive analysis concluded that a diet with 43% protein and 7% lipid, with a P/E ratio of 23.07 mg kJ−1, significantly promote the growth performance, feed utilization and health of juvenile greenfin horse-faced filefish. [ABSTRACT FROM AUTHOR]

In this work, PtCo nanoparticles (NPs) on hierarchically ordered mesoporous carbon (PtCo/OMC) are synthesized for polymer electrolyte membrane fuel cells (PEMFCs) aiming to improve the activity and durability of the Pt-based catalyst towards oxygen reduction reaction (ORR). Specifically, the OMC is prepared through a solvent evaporation-induced self-assembly (EISA) method by using a triblock copolymer PEO-PPO-PEO as the structure agent, followed by annealing in the nitrogen atmosphere to decompose the structure agent and to carbonize the carbon precursor. PtCo nanoparticles (NPs) are fabricated with an average diameter of 3.3 nm by H2 reduction and galvanic replacement in an acid solution, and then are uniformly dispersed onto the OMC via impregnation. The typical mesoporous structure of the OMC enhances the uniformly distribution and thermal stability of the small-sized PtCo NPs. The activity and the durability of the as-prepared PtCo/OMC catalyst are investigated by cyclic voltammetry (CV) and single-cell test. In the electrochemical tests, PtCo/OMC exhibits a high ECSA value of 88.56 m2g−1, and a ECSA retention of 77.5% after 5000 CV cycles. The results show that the PtCo/OMC catalyst is more active and more stable than the commercial-carbon-supported PtCo catalyst (PtCo/XC-72). PtCo nanoparticles (NPs) on hierarchically ordered mesoporous carbon (PtCo/OMC) are synthesized aiming to improve the activity and stability of the Pt-based catalyst for the oxygen reduction reaction (ORR). Due to the natural mesoporous and graphite-carbon nanostructure of the OMC, the as-prepared PtCo/OMC catalyst is more active and more stable than the PtCo NPs on the commercial Vulcan@ XC-72 support (PtCo/XC-72), showing great potential in proton exchange membrane fuel cells (PEMFCs). [ABSTRACT FROM AUTHOR]

A method is proposed in this paper to prepare a SiC slurry with SiC particles selected by an ultrasonic-assisted elutriation method to reduce substrate surface damage caused by abrasive particles during lapping. Sapphire substrate lapping experiments were carried out using the prepared SiC slurry, and the lapping performance of the slurry was analyzed. The experimental results show that the SiC particle size is a factor that directly affects the material removal rate and surface roughness Ra, of sapphire substrates. When a SiC slurry with a particle size of 630 nm was used, the material removal rate was 508 nm/h, and the surface roughness Ra was 1.9 nm; increasing the slurry concentration and the platen rotating speed can improve the material removal rate. In addition, the agglomeration of SiC particles in the slurry depends on the pH of the slurry. Efficient precision lapping of sapphire substrates can be achieved by selecting appropriately sized SiC particles and by adjusting the slurry pH to control the agglomeration and dispersion of SiC particlesto further reduce the scratches on the substrate surface during the lapping process. [ABSTRACT FROM AUTHOR]

The low-cost sodium (Na) metal anode has high specific capacity and is one of the most promising electrode materials for next generation high-energy density batteries. Unfortunately, it is also extremely reactive and suffers from severe side reactions with almost all electrolytes, which results in detrimental failures including uncontrollable growth of mossy structures, fast electrolyte depletion and short cycle life. We report here the in situ synthesis of composite sponges with sodiated NaxSnSb particles embedded in N-doped graphene (NG) frameworks for modulating Na anodes with significantly improved stability and fast charging capability. The sodiated NaxSnSb composites function as seeding particles that guide low-overpotential and smooth growth of Na metal whereas the NG wrapping layers protect the freshly plated Na metal from detrimental side reactions with the battery electrolyte. As a result, as high as 95% of the freshly plated Na metal can be reversibly stripped during battery operation and this efficiency can last hundreds of cycles. We further show that the Na3Sb phase in the NaxSnSb composites played critical roles as sponges with only the Na15Sn4 phase have much lower performance. Overall, the synergy of guided growth from NaxSnSb and shielding from NG allows multifunctional hosts that support Na anodes to cycle with nearly unchanged overpotential and charge transfer resistance for >500 cycles in both symmetric cells and full cells. The Na metal remained dense without measurable formation of unsafe dendrite or inactive mossy structures in these novel sponges even after aggressive cycling. [ABSTRACT FROM AUTHOR]

For the advanced surface-to-air missile, the accurate information of missile-target encounter is required. Based on the adaptive Kalman filter algorithm, an unbiased converted tracking method of radar seeker with velocity information is proposed. According to the current statistical model, the current acceleration is estimated by recursive least square algorithm with forgetting factor, and the state equation is obtained. By analyzing the unbiased conversion relations of position and velocity information from polar coordinates to Cartesian coordinates, the true unbiased converted measurement covariance and its estimation using measurements are deduced. And the measurement equation is acquired. With the state and error estimation result of filter, the estimation algorithm of the true unbiased converted measurement covariance is improved. The simulation results prove the good performance of the tracking method in both filtering accuracy and tracking speed. [ABSTRACT FROM AUTHOR]

Bimetallic CuAg nanoparticles were synthesized using uric acid as a stabilizer, Fe3O4 loaded CuAg nanoparticles (Fe3O4–CuAg NPs) were also fabricated, and the morphology and content of both CuAg NPs and Fe3O4–CuAg NPs were investigated. The bimetallic CuAg NPs can be used as a catalyst and exhibited superior catalytic performance in the hydrogenation of nitrophenols and potassium ferricyanide(III). Notably, the bimetallic CuAg NPs and Fe3O4–CuAg NPs showed better catalytic activity compared with the same amount of Ag NPs in the hydrogenation of 4-nitrophenol, with rate constants k of 20.02 × 10−3 s−1 and 20.19 × 10−3 s−1, respectively. The magnetic Fe3O4–CuAg NPs can be re-used as a catalyst at least five times, promoting the concept of recycling by improving the deficiency in the disposable use of colloidal nanoparticles. [ABSTRACT FROM AUTHOR]

A series of Ni-modified Mo2C catalysts with La2O3-stabilized ZrO2 supports were synthesized via template method coupled with incipient wetness impregnation and temperature-programmed carbonization. The catalyst was tested in dry reforming of methane (DRM) reaction at the temperature range from 973 to 1173 K in a fixed-bed quartz reactor under atmospheric pressure. XRD, Raman, BET, H2-TPD, SEM, EDS and TEM were conducted to characterize the phase constitution, the pore structure, the morphology and the crystal structure of the catalysts. Ni-Mo2C nanoparticles of ~ 3 nm diameter were obtained for these catalysts, and the La2O3-ZrO2 supports exhibited a cubic lattice structure with a sheet shape, which is believed to contain an abundant of oxygen vacancies. And the synergistic interaction between the oxygen vacancy in La-Zr-O solid solution and the Ni-Mo2C particles could decrease the apparent activation energy of CO2. Both of them are beneficial for accelerating DRM reaction. CH4 conversion of the best specimen catalyst reaches 94% at 1173 K, and the catalyst maintains its stability after 100-h reaction. The superior catalytic activity of NMLZ-7.5 is attributed to the improved BET surface area (33.2 m2/g), smaller crystallites, grain boundaries and oxidation-carbonization cycle of Ni-Mo2C. [ABSTRACT FROM AUTHOR]

The bridge deck sections used for long-span suspension bridges have evolved through the years, from the compact box deck girders geometrical configurations to twin-box and three-box bridge decks sections. The latest generation of split and multiple-box bridge decks proved to have better aerodynamic behavior; thus further optimization methods are sought for such geometrical configurations. A new type of multibox bridge deck, consisting of four aerodynamically shaped deck boxes, two side decks for the traffic lanes and two middle decks for the railway traffic, connected between them by stabilizing beams, was tested in the wind tunnel for identifying the flutter derivatives and to verify the aerodynamic performance of the proposed multibox deck. Aerodynamic static force coefficients were measured for the multibox bridge deck model, scaled 1 : 80, for Reynolds numbers up to 5.1 × 105, under angles of attack between −8° and 8°. Iterative Least Squares (ILS) method was employed for identifying the flutter derivatives of the multibox bridge deck model, based on the results obtained from the free vibration tests and based on the frequency analysis the critical flutter wind speed for the corresponding prototype of the multibox bridge was estimated at 188 m/s. [ABSTRACT FROM AUTHOR]

ABSTRACT Mechanism of the morphological changes between toroidal and rod-like nanostructures of P4VP-b-PS-b-P4VP amphiphilic triblock copolymer micelles has been investigated in aqueous solution. This transition is proved to be highly reversible and tunable upon changing temperature. The toroidal structure, evolving from fibers at 20 °C, can transform to rod-like morphology as the temperature either gradually or directly increases to 80 °C, and vice versa. However, the transition mechanisms are quite different in different temperature-changing processes. The structure and thickness of the micelles are dependent on the specific temperature, whereas the transition mechanism is related to the method of the temperature change. These morphological changes are considered as a result from the interaction parameter between the solvent and the copolymer blocks, especially the hydrophobic block. Our research complements the external control over the reversible morphological transition of block copolymer micelles without changing the composition of the system or introducing additional influencing factors. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 1450-1457 [ABSTRACT FROM AUTHOR]

Aims/Introduction Diabetes can increase the risk of cancers at several sites, but the association between diabetes and lung cancer remains unclear. We aimed to provide the quantitative estimates for the association between diabetes or antidiabetic treatment and lung cancer risk in the present meta-analysis. Materials and Methods Cohort studies were identified by searching the PubMed database (January 1960 through October 2012) and manually assessing the cited references in the retrieved articles. Study-specific relative risks ( RRs) and 95% confidence intervals ( CIs) were estimated using a random-effects model. Study quality was assessed using the Newcastle-Ottawa scale. Results A total of 19 cohort studies were included in the present meta-analysis. Of these, 14 studies focused on the association between diabetes and lung cancer incidence, and seven studies focused on the association between antidiabetic treatment and lung cancer incidence. Compared with non-diabetic individuals, diabetic patients do not have an increased risk of lung cancer ( RR = 1.04, 95% CI 0.87-1.24). The association between diabetes and lung cancer remained not statistically significant in subgroup analysis stratified by study characteristics, study quality, diabetes ascertainment or important confounders. A null association between insulin or biguanides therapy and lung cancer risk was found. However, the diabetic patients receiving thiazolidinedione ( TZD) treatment had a 20% reduced risk of lung cancer than those without TZD treatment. Conclusions No association between diabetes and lung cancer risk was found. However, TZD treatment might reduce lung cancer risk in diabetic patients. [ABSTRACT FROM AUTHOR]

In a proton exchange membrane (PEM) water electrolyser, Pt‐coated porous titanium plate always acts as the current collector both in the anode and cathode. However, the Pt particles on the Ti current collector cannot take part in the electrochemical reactions and thus lead to a lower utilization of the noble metal. In this work, the Pt‐coated Ti current collector is directly used as the cathode in the PEM water electrolyser instead of the conventional Pt/C electrode. To improve the performance, Nafion ionomer is coated on the Pt/Ti electrode to enlarge the electrochemical surface area (ECSA); the ECSA of the Pt/Ti electrode is increased by six times, and the utilization of Pt can be elevated to 45%. The voltage of the electrolyser with the Pt/Ti electrode is only 31 mV higher than the conventional Pt/C catalyst layer at 1 A cm−2. After stability tests, an obvious membrane thinning is observed using Pt/C as the cathode while the membrane of the electrolyser with the ionomer‐coated Pt/Ti cathode does not show a significant change in thickness. The F ion emission rate shows the membrane degradation rate is reduced by 15 times compared with the conventional Pt/C cathode. [ABSTRACT FROM AUTHOR]