Conserved antigen structures and antibody-driven variations on foot-and-mouth disease virus serotype A revealed by bovine neutralizing monoclonal antibodies.

Foot-and-mouth disease virus (FMDV) serotype A is antigenically most variable within serotypes. The structures of conserved and variable antigenic sites were not well resolved. Here, a historical A/AF72 strain from A22 lineage and a latest A/GDMM/2013 strain from G2 genotype of Sea97 lineage were respectively used as bait antigen to screen single B cell antibodies from bovine sequentially vaccinated with A/WH/CHA/09 (G1 genotype of Sea97 lineage), A/GDMM/2013 and A/AF72 antigens. Total of 39 strain-specific and 5 broad neutralizing antibodies (bnAbs) were isolated and characterized. Two conserved antigenic sites were revealed by the Cryo-EM structures of FMDV serotype A with two bnAbs W2 and W125. The contact sites with both VH and VL of W125 were closely around icosahedral threefold axis and covered the B-C, E-F, and H-I loops on VP2 and the B-B knob and H-I loop on VP3; while contact sites with only VH of W2 concentrated on B-B knob, B-C and E-F loops on VP3 scattering around the three-fold axis of viral particle. Additional highly conserved epitopes also involved key residues of VP158, VP1147 and both VP272 / VP1147 as determined respectively by bnAb W153, W145 and W151-resistant mutants. Furthermore, the epitopes recognized by 20 strain-specific neutralization antibodies involved the key residues located on VP3 68 for A/AF72 (11/20) and VP3 175 position for A/GDMM/2013 (9/19), respectively, which revealed antigenic variation between different strains of serotype A. Analysis of antibody-driven variations on capsid of two virus strains showed a relatively stable VP2 and more variable VP3 and VP1. This study provided important information on conserve and variable antigen structures to design broad-spectrum molecular vaccine against FMDV serotype A.

Nanoporous germanium prepared by a mechanochemical reaction with enhanced lithium storage properties.

The cost-effective and facile fabrication of nanostructured germanium for lithium-ion batteries (LIBs) remains a grand challenge. Herein, nanoporous Z-Ge was generated via a facile two-step mechanochemical-etching reaction with Mg2Ge and ZnCl2. The prepared nanoporous Ge nanoparticles, as the anode for Li-Ge half cells, showed superior LIB performance, in terms of a high capacity, good rate capability, and good long-term stability of 700 cycles. Significantly, the mechanochemical reaction was extended to produce other nanoporous Ge or Si materials such as A-Ge, Z-Si, and A-Si via the mechanochemical reaction between Mg2Ge and AlCl3, Mg2Si and ZnCl2, and Mg2Si and AlCl3.

Scalable synthesis of 3D porous germanium encapsulated in nitrogen-doped carbon matrix as an ultra-long-cycle life anode for lithium-ion batteries.

Germanium-based materials attract more interest as anodes for lithium-ion batteries, stemming from their physical and chemical advantages. However, these materials inevitably undergo capacity attenuation caused by significant volumetric variation in repeated electrochemical processes. Herein, we designed 3D porous Ge/N-doped carbon nanocomposites by the encapsulation of 3D porous Ge in a nitrogen-doped carbon matrix (denoted as 3D porous Ge/NC). The 3D porous structure can accommodate the volume change during alloying/dealloying processes and improve the penetration of the electrolyte. Furthermore, the doping of N in the carbon framework could introduce more defects and active sites, which can also contribute to electron transportation and lithium-ion diffusion. The half-cell test found that at a current density of 1 C (1 C = 1600 mA h g-1), the specific capacity stabilized at 917.9 mA h g-1 after 800 cycles; and the specific capacity remained at 542.4 mA h g-1 at 10 C. When assembled into a 3D porous Ge/NC//LiFePO4 full cell, the specific capacity was stabilized at 101.3 mA h g-1 for 100 cycles at a current density of 1 C (1 C = 170 mA h g-1), and the cycle specific capacity was maintained at 72.6 mA h g-1 at a high current density of 5 C. This work develops a low-cost, scalable and simple strategy to improve the electrochemical performance of these alloying type anode materials with huge volume change in the energy storage area.

[Quality evaluation of angelica broken wall powder based on QbD concept of traditional Chinese medicine].

In this paper, angelica broken wall powder(ABWP) was taken as the research object, HPLC fingerprint combined with multi-component determination(ferulic acid, senkyunolide I, coniferyl ferulate, ligustilide and 3-butylidenephthalide), physical fingerprint(D_(90), particle size distribution range, particle size distribution width, bulk density, tap density, inter-particle porosity, Carr index, specific surface area, pore volume, angle of repose, Hausner ratio, loss on drying and hygroscopicity)were used to characterize the quality attribute of ABWP; similarity analysis, cluster analysis, principal component analysis and orthogonal partial least squares discriminant analysis were conducted to construct the quality evaluation method of holographic analysis based on traditional Chinese medicine QbD "4 H mode", in order to evaluate the quality of ABWP from different sources and find out differentiated indicators. The quality evaluation method could be used for scientific, comprehensive evaluation of the quality attribute of ABWP, and the quality consistency evaluation of cell-wall-broken powder of different sources or different processes.It provides new ideas for quality control and research of ultrafine granular powders of traditional Chinese medicine.

Carbon nanotube-stabilized Co9S8 dual-shell hollow spheres for high-performance K-ion storage.

In this work, carbon nanotube-coated dual-shell Co9S8 hollow spheres are studied as anode materials for K-ion batteries. The unique hollow structure and carbon nanotubes synergistically enhance the conductivity and resolve the critical drawbacks of Co9S8 electrodes, including large volume variation, structural instability and interfacial changes. Thus, the electrode delivers a stable reversible capacity of 320.5 mA h g-1 at 0.1 A g-1 after 200 cycles with a capacity retention of 91%. At 1.0 A g-1, the capacity is 163.9 mA h g-1 after 1000 cycles with a capacity retention of 73.6%. An investigation of the electrode reaction mechanism indicates that the surface capacity also contributes to the outstanding electrochemical performance.

Mesoporous Hollow Ge Microspheres Prepared via Molten-Salt Metallothermic Reaction for High-Performance Li-Storage Anode.

Generally, Ge-based anodes are prepared by metallothermic reduction of GeO2 with Mg at 650 °C. Herein, a molten-salt system is developed a low-temperature metallothermic reduction of GeO2 to prepare nanostructured Ge based anode materials. Typically, mesoporous hollow Ge microspheres are prepared by reduction of GeO2 with metallic Mg in molten ZnCl2 (mp 292) at 350 °C. Monodispersed Ge particles are synthesized through reduction of GeO2 with Mg in molten AlCl3 (mp 192 °C) at 250 °C. The meso-porous Ge anode delivers the reversible capacity of 1291 mA h g-1 at 0.2 C after 150 cycles with a retention of 97.3%, 1217 mA h g-1 at 0.8 C after 400 cycles with a retention of 91.9%, and superior rate capability with a capacity of 673 mA h g-1 even at 10 C. Then, the reaction mechanism and full-cell performance of as-prepared Ge anodes are studied systemically.

Synthesis and Antimicrobial Activities of 3-Methyl-ß-Carboline Derivatives.

The ß-carboline alkaloids possess a diverse range of important biochemical effects and pharmacological properties. Sixteen 3-methyl-ß-carboline derivatives were synthesized from indole formaldehyde and nitroethane via the Henry reaction, LAH/THF reduction, the Pictet-Spengler reaction and Pd/C/xylene oxidation, including four 1-substituted and twelve 9-substituted 3-methyl- ß-carboline derivatives. The structures of all the derivatives were confirmed by 1H NMR, 13C NMR and ESI-MS. Most of these 3-methyl-ß-carboline derivatives showed some antibacterial activity.

Synthesis and insecticidal activities of novel nitrogenous derivatives of celangulin-V.

In order to develop new biorational pesticides and clarify the potential structural factors needed for the biological activity of celangulin-V analogues, thirty novel nitrogenous derivatives were designed and synthesized. The single crystal structure of celangulin-V is reported for the first time and provides a more accurate structure than that previously reported. The structures of all the new derivatives were confirmed by either NMR or ESI-MSn analysis. Insecticidal activities of these compounds were tested against the third-instar larvae of Mythimna separata. One derivative (1-6) showed higher insecticidal activity than celangulin-V, with a KD50 of 231.2 microg.g(-1), while two compounds (2-13 and 2-14) exhibited lower insecticidal activities; the others revealed no activity at a concentration of 20 mg mL(-1). The results support the view that celangulin-V has the potential to be a lead structure of semi-synthetic green insecticides.

Synthesis and bioactivity of beta-carboline derivatives.

The beta-carboline alkaloids possess a wide diversity of important biochemical effects and pharmacological properties. A series of beta-carboline derivatives were synthesized from L-tryptophan through the Pictet-Spengler reaction and oxidation of K2Cr2O7 by a sequential one-pot synthesis method. In vitro anti-bacterial, insecticidal, and cytotoxic activities of all synthesized compounds were investigated by the tablet diffusion, leaf disc, and MTT methods, respectively. Some of the compounds (1-1, 1-2, 1-3 and 1-12) exhibited obvious anti-bacterial effects and some (1-3) had significant cytotoxic activities against tumor cells 3LL, MCF-7, BGC-823 and QGY-7701, with IC50 values of 7.79, 5.75, 3.53 and 4.02 microg/mL, respectively. No insecticidal activity against third stage instar larvae of Mythimna separata Walker were observed under the tested concentration.