Theoretical Studies on the Electronic Properties of R_2M_(14)B (R = Lanthanides from La to Lu;M = Mn,Fe, Co,and Ni)

To search for an alternative for Nd₂Fe₁₄B,we have studied the electronic structures of R₂M₁₄B compounds,where R stands for rare-earth element and M for Mn,Fe,Co and Ni.By density functional theory(DFT),we discuss the atomic coordination environment and partial density of states(PDOS)in detail,with the emphasis on the interaction between the six kinds of M sites and the R atoms.We systemically calculated the electronic structures of sixty R₂M₁₄B compounds to provide systematic and reliable results for explaining the origination of magnetism,which is important for further development of Nd₂Fe₁₄B based magnet materials.     

A Redox-responsive Prodrug Nanogel of TLR7/8 Agonist for Improved Cancer Immunotherapy

The existence of tumor immunosuppressive microenvironment(TIME) is the major determinant for the poor efficacy of current tumor immunotherapy. Tumor-associated macrophages(TAMs) tend to become tumor-promoting M2-like phenotype and hinder immune response in solid tumors. Repolarization of TAMs from M2 to anti-tumor M1 phenotype is robust for remodeling the TIME. Herein, we developed a redoxresponsive nanogel as the delivery system of Toll-like receptor 7 and 8(TLR7/8) agonist(R848) prodrug for po...     

Electrochemical Impedance Spectroscopic Measurements of Sexithiophene—Effect of the Electrode Nature and the Dopant (CuCl2) Content

Electrochemical impedance spectroscopic (EIS) measurements of sexithiophene (6T) were carried out according to the Pt/6T/M sandwich structure configuration, for various electrode materials (M＝GC, ITO, Ag, Cu, Al) and for different doping levels of copper chloride (CuCl2). The results demonstrate that two types of charge transport are involved in the redox process at the electrode/6T interface and inside the bulk oligomer. The complex-plane impedance plots obtained for various doping levels of CuCl2 exhibit arc shapes. The charge-transfer resistance measured from the diagrams decreases systematically with the addition of the salt, leading to an increase of the oligothiophene conductivity.     

Face-centered cubic structured RuCu hollow urchin-like nanospheres enable remarkable hydrogen evolution catalysis

Ruthenium(Ru)is one of the most promising metals for its versatility in driving a wide range of catalytic reactions.However,owing to the intrinsic preference of hexagonal close-packed(hcp)phase for bulk Ru,currently,it is still challenging to construct Ru-based nanomaterials with face-centered-cubic(fcc)phase for optimizing their performance towards potential applications.Herein,we report a facile wet-chemical method to directly create unconventional fcc-structured Ru-copper hollow urchin-like nanospheres(fcc-RuCu HUNSs)as a class of efficient pH-universal hydrogen evolution reaction(HER)electrocatalyst.Interestingly,this synthetic strategy can be expanded to prepare other fcc-Ru-based alloy nanomaterials.Significantly,the novel fcc-RuCu HUNSs exhibit superior HER performance with the overpotential of only 25,34,40,and 26 m V to reach the current density of 10 mA cm^-2in 0.5 M H₂SO₄,0.05 M H₂SO₄,0.1 M KOH,and 1 M KOH,respectively,much lower than those of hcpRuCu HUNSs and commercial Pt/C.Density functional theory(DFT)calculations further indicate that their excellent pH-universal HER performance results from the optimized adsorption free energy of H and work functions.Our work highlights the importance of phase control to design high-efficiency nanocatalysts for relevant catalytic reactions in energy conversion.     

COLIPHAGE M13 CLONING SYSTEM AND ddXTP CHAIN-TERMINATION METHOD FOR DNA SEQUENCING

Two DNA fragments of cytochrome b gene in yeast mitochondral DNA were sequenced by Messing's M13 cloning system and Sanger's ddXTP chain-termination method. M13mp8 and M13mp9 serve as vectors for insert fragment. The recipient strain is E. coli JM103 for transfection. When the ratio of insert/vector was 3:1, high frequencies of recombination and positive recombination were obtained. The two fragments, which have 575 bp and 709 bp, were sequenced. To read more bases, the ratio of ddXTP/dXTP must be reduced. On one X-ray film of 80×17cm 394 bp were read.     

STUDIES IN MONKEYS OF ATTENUATED HEPATITIS A VARIANTS

Three HAV variants, H2M20(35℃), H2M20(32℃) and H2M20K5(32℃), were developed by passagein different tissue culture cells and at different temperatures. Virulence for monkeys was assessed by in-oculating each of the variants into four monkeys. Weekly bleeding through 16 weeks post-inoculation wasassayed for anti-HAV titers and SGPT as well as LDH5 activities. And in some monkeys liver biopsieswere also studied. Seroconversion was induced in all of the inoculated monkeys. The anti-HAV titers test-ed at 16 weeks post-inoculation were: 40-640 with H2M20(35℃), 40-160 wi1h H2M20(32℃) and 20-40 with H2M20K5(32℃). These variants showed different levels of virulence/attenuation for monkeys.Variant H2M20(35℃) showed no evidence of attenuation, variant H2M20(32℃) retained slight virulenceand variant H2M20K5(32℃) showed no evidence of virulence for monkeys. Criteria are proposed for as-say of HAV virulence tested in monkeys.     

Hydrothermal conversion of lignocellulosic biomass into high-value energy storage materials

Preparation of hierarchically porous, heteroatom-rich nanostructured carbons through green and scalable routes plays a key role for practical energy storage applications. In this work, naturally abundant lignocellulosic agricultural waste with high initial oxygen content, hazelnut shells, were hydrothermally carbonized and converted into nanostructured ‘hydrochar'. Environmentally benign ceramic/magnesium oxide(Mg O) templating was used to introduce porosity into the hydrochar. Electrochemical performance of the resulting material(HM700) was investigated in aqueous solutions of 1 M H_2SO_4, 6 M KOH and1 M Na_2SO_4, using a three-electrode cell. HM700 achieved a high specific capacitance of 323.2 F/g in 1 M H_2SO_4(at 1 A/g,-0.3 to 0.9 V vs. Ag/Ag Cl) due to the contributions of oxygen heteroatoms(13.5 wt%)to the total capacitance by pseudo-capacitive effect. Moreover, a maximum energy density of 11.1 Wh/kg and a maximum power density of 3686.2 W/kg were attained for the symmetric supercapacitor employing HM700 as electrode material(1 M Na_2SO_4, E = 2 V), making the device promising for green supercapacitor applications.     

Dual functional AgNPs-M13 phage composite serves as antibacterial film and sensing probe for monitoring the corrosion of chromium-containing dental alloys

The preparation of silver nanoparticles(AgNPs)with microbe or plant tissues as bio-template offers green approach,while it suffers from low harvest and purification is needed.Herein,we propose a facile protocol for one-pot preparation of AgNPs using M13 phage as bio-template by simply mixing AgN03 solution with alkali M13 phage.In the obtained AgNPs-M13 phage composite,Cr(Ⅲ)selectively coordinates with the amino residues on phage surface and leads to the aggregation of AgNPs through the bridging of M13 phages.This makes it feasible for colorimetric sensing of Cr(Ⅲ)by measuring the absorbance ratio of AgNPs at 600 and 405 nm,which provides a LOD of 14 nmol/L.The composite also showed favorable bactericidal activity for both Gram-positive and Gram-negative bacteria,making it a promising candidate as antibacterial film in chromium-containing dental alloys and meanwhile serve as a sensing probe for monitoring the corrosion of the dental alloys.     

Adsorption of NO on the M/c-ZrO2(110) (M = Ru,Rh) Surface: A Density Functional Theory Study

<正>The adsorption of NO on the M/c-ZrO_2(110)(M=Ru,Rh)surface has been studied with periodic slab model by PW91 approach of GGA within the framework of density functional theory.The results of geometry optimization indicated that the hollow site is energetically stable for Ru and Rh atoms' adsorption on the c-ZrO_2(110)surface with adsorption energies of 207.4 and 106.3 kJ/mol,respectively.When NO is adsorbed on the M/ZrO_2(110)surface,the N-down adsorption is the most stable.We also studied the adsorption of double NO on the M/c-ZrO_2(110)surface.Complete linear synchronous transit and quadratic synchronous transit approaches were used to search the transition state for dissociation reaction.NO has two possible dissociation passways:(1)2NO→N_2(g)+20(ads),(2)2NO→N_2O(g)+O(ads),and the former is easier than the latter based on the calculation results.