Highly potent multivalent VHH antibodies against Chikungunya isolated from an alpaca naïve phage display library

Background Chikungunya virus (CHIKV) is a re-emerged mosquito-borne alphavirus that can cause musculoskeletal diseases, imposing a substantial threat to public health globally. High-affinity antibodies are need for diagnosis and treatment of CHIKV infections. As a potential diagnostic and therapeutic agent, the multivalent VHH antibodies is a promising tookit in nanomedicine. Here, we developed potent multivalent VHH antibodies from an alpaca naïve phage display library targeting the E2 glycoprotein of the CHIKV virus. Results In the present study, we generated 20 VHH antibodies using a naïve phage display library for binders to the CHIKV E2 glycoprotein. Of these, multivalent VHH antibodies Nb-2E8 and Nb-3C5 had specific high-affinity binding to E2 protein within the nanomolar range. The equilibrium dissociation constant (KD) was between 2.59–20.7 nM, which was 100-fold stronger than the monovalent antibodies’ affinity. Moreover, epitope mapping showed that Nb-2E8 and Nb-3C5 recognized different linear epitopes located on the E2 glycoprotein domain C and A, respectively. A facile protocol of sandwich ELISA was established using BiNb-2E8 as a capture antibody and HRP-conjugated BiNb-3C5 as a detection antibody. A good linear correlation was achieved between the OD450 value and the E2 protein concentration in the 5–1000 ng/mL range (r = 0.9864, P < 0.0001), indicating its potential for quantitative detection of the E2 protein. Conclusions Compared to monovalent antibodies, multivalent VHH antibodies Nb-2E8 and Nb-3C5 showed high affinity and are potential candidates for diagnostic applications to better detect CHIKV virions in sera. Graphical Abstrac

Nitrogen-doped hydrochars from shrimp waste as visible-light photocatalysts: Roles of nitrogen species

The increasing shrimp waste production has caused severe environmental problems. In this study, nitrogen doped hydrochars (NDHCs) were facilely synthesized from shrimp waste and glucose by one-pot hydrothermal carbonization (HTC). The characterizations showed that NDHCs had large surface areas of up to 30.5 m(2) g(-1) with numerous functional groups on their porous surfaces. The nitrogen content (1.3-2.8%) and species distribution in NDHCs were associated with the amount of added glucose. These NDHCs were applied as visible-light-induced photocatalysts, and their photocatalytic performances were evaluated by methylene blue (MB) degradation. The removal rate of MB reached 88.9% after 1 h of visible light radiation by NDHC-1, which was 2.3 times higher than that of glucose-derived hydrochar (GHC). The mechanism study showed that the improved photoactivity of NDHCs was attributed to the increased adsorption capacity by porous surface and the promoted formation of hydroxyl radicals by synergistic effects of quaternary N and pyrrolic N during photocatalysis. This study offered a green approach to preparing tunable, efficient, and low-cost photocatalyst from waste biomass and insight into the photocatalytic mechanism of hydrochar materials

DAN: Deep Attention Neural Network for News Recommendation

With the rapid information explosion of news, making personalized news recommendation for users becomes an increasingly challenging problem. Many existing recommendation methods that regard the recommendation procedure as the static process, have achieved better recommendation performance. However, they usually fail with the dynamic diversity of news and user’s interests, or ignore the importance of sequential information of user’s clicking selection. In this paper, taking full advantages of convolution neural network (CNN), recurrent neural network (RNN) and attention mechanism, we propose a deep attention neural network DAN for news recommendation. Our DAN model presents to use attention-based parallel CNN for aggregating user’s interest features and attention-based RNN for capturing richer hidden sequential features of user’s clicks, and combines these features for new recommendation. We conduct experiment on real-world news data sets, and the experimental results demonstrate the superiority and effectiveness of our proposed DAN model

Waste-biomass tar functionalized carbon spheres with N/P Co-doping and hierarchical pores as sustainable low-cost energy storage materials

Biomass tar has exhibited promising potential for fabricating carbon-based functional materials. In this study, carbon materials with hierarchical pores, N/P co-doping, and oxygen-rich functional groups were prepared from glucose and biomass tar via a hydrothermal treatment combined with H3PO4 activation strategy and their electrochemical performances were evaluated. The results showed that the coating of tar inhibited agglomeration of carbon sphere derived from glucose and regulated its surface properties, resulting in hierarchical porous structure and surface functional groups. During thermal treatment, the resultant carbon materials were appropriately self-heteroatom doped by N and P from tar and H3PO4, respectively. Due to the unique structure, the specific capacitance of as-prepared carbon electrode was 199 F g(-1). The symmetric TGC-60 0 capacitor showed excellent electrochemical properties with specific capacitance of 175 F g(-1) and energy density of 6.1 Wh kg(-1). Furthermore, TGC-60 0 capacitor showed superior cyclic stability, the capacitance retention was around 92% after 5000 runs. This study offered a green and low-cost utilization approach for biomass tar to prepare supercapacitor with excellent electrochemical performance. (C) 2022 Elsevier Ltd. All rights reserved

Waste-biomass tar functionalized carbon spheres with N/P Co-doping and hierarchical pores as sustainable low-cost energy storage materials

Biomass tar has exhibited promising potential for fabricating carbon-based functional materials. In this study, carbon materials with hierarchical pores, N/P co-doping, and oxygen-rich functional groups were prepared from glucose and biomass tar via a hydrothermal treatment combined with H3PO4 activation strategy and their electrochemical performances were evaluated. The results showed that the coating of tar inhibited agglomeration of carbon sphere derived from glucose and regulated its surface properties, resulting in hierarchical porous structure and surface functional groups. During thermal treatment, the resultant carbon materials were appropriately self-heteroatom doped by N and P from tar and H3PO4, respectively. Due to the unique structure, the specific capacitance of as-prepared carbon electrode was 199 F g(-1). The symmetric TGC-60 0 capacitor showed excellent electrochemical properties with specific capacitance of 175 F g(-1) and energy density of 6.1 Wh kg(-1). Furthermore, TGC-60 0 capacitor showed superior cyclic stability, the capacitance retention was around 92% after 5000 runs. This study offered a green and low-cost utilization approach for biomass tar to prepare supercapacitor with excellent electrochemical performance. (C) 2022 Elsevier Ltd. All rights reserved

A High-Power-Density Single-Phase Rectifier Based on Three-Level Neutral-Point Clamped Circuits

A single-phase three-level converter is suitable for medium-power applications, with an interface voltage that is higher than that of a traditional two-level configuration. The three-level neutral-point clamped converter is adopted using four switches in each bridge arm, which, compared to a two-level rectifier, leads to less voltage stress, a lower switching frequency, and switching loss on switches. The transient current control strategy is designed to control the active power. The single-phase space vector pulse width modulation (SVPWM) with a voltage balance strategy is designed to solve the neutral point voltage fluctuation problem and keep the dc-link voltage stable. A 1.3 kW high-power-density prototype based on SiC MOSFET was built and tested. The experimental results verified the high performance of steady-state and dynamic responses

A Traction Three-Phase to Single-Phase Cascade Converter Substation in an Advanced Traction Power Supply System

The advanced traction power supply system (ATPSS) is a new directional development for traction power supply systems, which can totally remove the neutral sections and effectively promote power quality. However, the existing converters suffer from small substation capacity. In this paper, a new configuration based on a three-level neutral point clamped (3L-NPC) three-phase to single-phase cascade converter in a substation is proposed for ATPSS, which can be used to match the capacity of the converter for high voltage and large power applications. The control strategy of the proposed converter is analyzed in depth, and the phase disposition sinusoidal pulse width modulation (PD-SPWM) with phase shift carrier SPWM (PSC-SPWM) is employed in the inverters. Then, the inductance equalizing circuit is applied for the voltage balance on the DC-link. Besides, a LC filter circuit is designed to eliminate the double line-frequency ripple of DC voltage. Afterwards, a simulation model and an experimental prototype are developed, respectively. The simulation results show that the proposed converter in this paper can not only meet the requirements of voltage and capacity for the traction network, but also improve power quality. Finally, the experimental results verify the correctness and feasibility of the proposed control strategy