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1.
Science ; 385(6714): 1217-1224, 2024 Sep 13.
Article in English | MEDLINE | ID: mdl-39264996

ABSTRACT

Chronic hepatitis B virus (HBV) infection poses a major global health challenge with massive morbidity and mortality. Despite a preventive vaccine, current treatments provide limited virus clearance, necessitating lifelong commitment. The HBV surface antigen (HBsAg) is crucial for diagnosis and prognosis, yet its high-resolution structure and assembly on the virus envelope remain elusive. Utilizing extensive datasets and advanced cryo-electron microscopy analysis, we present structural insights into HBsAg at a near-atomic resolution of 3.7 angstroms. HBsAg homodimers assemble into subviral particles with D2- and D4-like quasisymmetry, elucidating the dense-packing rules and structural adaptability of HBsAg. These findings provide insights into how HBsAg assembles into higher-order filaments and interacts with the capsid to form virions.


Subject(s)
Capsid , Hepatitis B Surface Antigens , Hepatitis B virus , Virion , Humans , Capsid/chemistry , Capsid/ultrastructure , Cryoelectron Microscopy , Hepatitis B Surface Antigens/chemistry , Hepatitis B virus/ultrastructure , Hepatitis B virus/chemistry , Hepatitis B virus/physiology , Protein Multimerization , Viral Envelope/chemistry , Viral Envelope/ultrastructure , Virion/ultrastructure , Virion/chemistry , Virus Assembly , Hepatitis B, Chronic/virology , Datasets as Topic
2.
J Chromatogr A ; 1733: 465228, 2024 Sep 27.
Article in English | MEDLINE | ID: mdl-39163701

ABSTRACT

In this study, using chiral L-lysine as the molecular skeleton, three kinds of L-lysine-derived gelators (GBLB, GBLF and GFLF) were synthesized and then bonded to the surface of silica matrix (5 µm) by amide condensation to prepare a series of multifunctional chromatography stationary phases (GBLB-SiO2, GBLF-SiO2, and GFLF-SiO2) were prepared. The L-lysine-derived gelators not only possess chiral recognition ability, but also can spontaneously form oriented and ordered network structures in liquid medium through the interaction of non-covalent bonding forces such as hydrogen bonding, π-π stacking, and van der Waals forces. The comprehensive effect of multiple weak interaction sites enhances the molecular recognition ability and further improves the separation diversity of different types of compounds on stationary phases. The separation and evaluation of chiral compounds showed that benzoin, 1-phenyl-ethanol, 1-phenyl-propanol and 6-hydroxyflavanone could be separated in normal phase mode (NPLC). The separation of different types of non-chiral compounds, such as sulfonamides, nucleosides, nucleobases, polycyclic aromatic hydrocarbons (PAHs), anilines, and aromatic acids, were achieved in hydrophilic interaction/reversed-phase/ion-exchange mode (HILIC/RPLC/IEC), and the separation of polarized compounds could be performed under the condition of ultrapure water as the mobile phase, which has the typical retention characteristics of per aqueous liquid chromatography (PALC). The effects of organic solvent content, temperature, pH value, and buffer salt concentration on the retention and separation performance of the column were investigated. Comparison of the three prepared columns showed that the separation performance (such as aromatic selectivity) could be improved by increasing the types of functional groups on the surface of the stationary phase and the number of aromatic groups. In a word, the prepared stationary phase have multiple retention properties, can simultaneously separate chiral compounds and various types of achiral compounds. This work provides an idea for developing multifunctional liquid chromatography stationary phase materials, and further expands the application of gelators in separation science.


Subject(s)
Hydrophobic and Hydrophilic Interactions , Lysine , Silicon Dioxide , Stereoisomerism , Lysine/chemistry , Silicon Dioxide/chemistry , Chromatography, High Pressure Liquid/methods
3.
J Chromatogr A ; 1733: 465249, 2024 Sep 27.
Article in English | MEDLINE | ID: mdl-39178658

ABSTRACT

Geometric isomers tend to have similar polarities and differ only in molecular shape. Vigorously developing new stationary phases to meet the requirements for the separation of isomers that have similar physicochemical properties is still an urgent topic in separation science. Poly (arylene ether)-based dendrimers are known for their multifunctional branched peripheral structures and high self-assembly properties. In this paper, two amphiphilic dendritic organic small molecule gelling agents based on poly (aryl ether), PAE-ANT and PAE-PA, were prepared and conjugated to the silica surface. SiO2@PAE-ANT and SiO2@PAE-PA were used as HPLC stationary phases for the separation of non-polar shape-restricted isomers. Both stationary phases have very high molecular shape selectivity for isomers such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), tocopherols and carotenoids. Separation of cis-trans geometric isomers such as diethylstilbestrol and polar compounds such as monosubstituted benzenes and anilines can also be achieved. These two columns offer more flexible selectivity and higher separation performance than commercial C18 and phenyl columns. There is a difference in molecular shape selectivity between the two stationary phases for the same analyte test probes. SiO2@PAE-ANT showed slightly better linear selectivity for non-polar shape-restricted isomers compared to SiO2@PAE-PA with Janus-type PAE-PA bonding phase. This separation behavior may be attributed to the ordered spatial structure formed by the gel factor on the surface of the stationary phase and the combined effect of multiple weak interaction centers (hydrophobic, hydrophilic, hydrogen bonding and π-π interactions). It was also possible to separate nucleoside and nucleobase strongly polar compounds well in the HILIC mode, suggesting that hydrophilic groups in PAE-ANT and PAE-PA are involved in the interactions, reflecting their amphiphilic nature. The results show that the ordered gelation of dendritic organic small molecule gelators on the SiO2 surface, along with multiple carbonyl-π, π-π and other interactions, play a crucial role in the separating shape-restricted isomers. The integrated and ordered functional groups serve as the primary driving force behind the exceptionally high molecular shape selectivity of SiO2@PAE-ANT and SiO2@PAE-PA phases. Alterations in the structure of dendritic organic small molecule gelators can impact both molecular orientation and recognition ability, while changes in the type of functional groups influences the separation mechanism of shape-restricted isomers.


Subject(s)
Dendrimers , Silicon Dioxide , Silicon Dioxide/chemistry , Chromatography, High Pressure Liquid/methods , Isomerism , Dendrimers/chemistry , Polycyclic Aromatic Hydrocarbons/chemistry , Polycyclic Aromatic Hydrocarbons/analysis , Polycyclic Aromatic Hydrocarbons/isolation & purification , Polychlorinated Biphenyls/chemistry , Polychlorinated Biphenyls/analysis , Polychlorinated Biphenyls/isolation & purification , Carotenoids/chemistry , Carotenoids/analysis , Carotenoids/isolation & purification , Surface-Active Agents/chemistry
4.
Environ Sci Pollut Res Int ; 31(25): 36849-36860, 2024 May.
Article in English | MEDLINE | ID: mdl-38758436

ABSTRACT

A hydrothermal synthesis method was developed to produce high crystallinity ZSM-5 zeolite using coal gasification coarse slag (CGCS) as the raw material. Instead of the expensive NaOH(s.), Na2SiO3(s.) was utilized to activate, depolymerize, and recombine Si and Al elements in the CGCS. The mother liquor circulation technology was employed to recover and reuse raw materials and residual reagents (Na2SiO3(aq.) and TPABr), reducing waste emissions and enhancing resource utilization efficiency. The synthesized ZSM-5 had a specific surface area of 455.675 m2 g-1, pore volume of 0.284 cm3 g-1, and pore diameter of 2.496 nm. The influence of various factors on the morphology and crystallinity of ZSM-5 was investigated, resulting in the production of ZSM-5 with higher specific surface area and pore volume. Adsorption experiments showed that WU-ZSM-5 exhibited a removal efficiency of 85% for ammonia nitrogen (NH4+-N(aq.)), validating its effectiveness in coal chemical wastewater purification. The mother liquor recycling technology enabled zero-emission utilization of solid waste resources and improved the utilization rate of alkali and template to 90%. These results demonstrate the potential application of the developed method in the efficient treatment of coal chemical wastewater.


Subject(s)
Coal , Wastewater , Zeolites , Zeolites/chemistry , Wastewater/chemistry , Adsorption , Waste Disposal, Fluid/methods , Water Purification/methods
5.
Anal Chim Acta ; 1288: 342156, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38220288

ABSTRACT

BACKGROUND: Molecular shape selectivity, based on the size and shape parameters of the molecule, such as length and planarity, is a separation process that can be used for compounds with restricted shapes, such as isomers. The separation of geometric isomers is challenging because these compounds have similar physicochemical properties but differ slightly in molecular shape. The ability to separate and quantify these isomers is important in high performance liquid chromatography (HPLC), which is one of the most widely used techniques in separation science today, because the shape of the molecule has a strong influence on biological processes. RESULTS: We prepared symmetrical discoidal dendrimeric organomolecule gelators (GSDM) and o-phenylenediamine-derived low-molecular-weight dendrimeric organomolecule gelators (G1) and bonded them to silica surfaces. The dendritic organic compound-grafted silica (SiO2@GSDM and SiO2@G1) was used as HPLC stationary phases for the separation of shape-restricted isomers of polycyclic aromatic hydrocarbons (PAHs), carotenoids and tocopherols. The two phases exhibit a very high molecular shape selectivity compared to the commercially available alkyl phases. There are differences in molecular shape selectivity between the two stationary phases. Changes in the chemical structure of dendritic organic compounds can alter the orientation of the molecules, as well as changes in the molecular recognition ability. It was found that SiO2@GSDM has high molecular linear selectivity for PAHs at different temperatures, even at 50 °C. The planar selectivity of SiO2@GSDM was better for triphenylene and o-terphenyl benzenes compared to SiO2@G1. SIGNIFICANCE: This separation behavior may be attributed to the combined effect of weak interaction centers, which allowed the effective separation of bioactive and shape-restricted isomers through multiple interactions. Furthermore, SiO2@GSDM showed better separation of tocopherols and carotenoids, suggesting that the backbone and ordered structure of organic molecular gelators is an effective way to improve the shape selectivity of the molecules, whereas the molecular orientation of the functional groups influences the separation mechanism of the shape-restricted isomers.

6.
ACS Synth Biol ; 13(1): 269-281, 2024 Jan 19.
Article in English | MEDLINE | ID: mdl-38061052

ABSTRACT

CRISPR-Cas9 systems have been widely harnessed for diverse genome editing applications because of their ease of use and high efficiency. However, the large molecular sizes and strict PAM requirements of commonly used CRISPR-Cas9 systems restrict their broad applications in therapeutics. Here, we report the molecular basis and genome editing applications of a novel compact type II-A Eubacterium ventriosum CRISPR-Cas9 system (EvCas9) with 1107 residues and distinct 5'-NNGDGN-3' (where D represents A, T, or G) PAM specificity. We determine the cryo-EM structure of EvCas9 in a complex with an sgRNA and a target DNA, revealing the detailed PAM recognition and sgRNA and target DNA association mechanisms. Additionally, we demonstrate the robust genome editing capacity of EvCas9 in bacteria and human cells with superior fidelity compared to SaCas9 and SpCas9, and we engineer it to be efficient base editors by fusing a cytidine or adenosine deaminase. Collectively, our results facilitate further understanding of CRISPR-Cas9 working mechanisms and expand the compact CRISPR-Cas9 toolbox.


Subject(s)
CRISPR-Cas Systems , Eubacterium , Gene Editing , Humans , Gene Editing/methods , CRISPR-Cas Systems/genetics , RNA, Guide, CRISPR-Cas Systems , DNA/genetics
7.
Int J Biol Macromol ; 258(Pt 1): 128772, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38103670

ABSTRACT

This study prepared type 3, type 4, and type 5 quinoa resistant starch (QRS3, QRS4, and QRS5) from quinoa starch (QS), compared their structural and physicochemical properties and evaluated their noodle-making potential. The results showed that the molecular weight of QRS3 decreased, the number of short-chain molecules increased, and its crystal type changed to B-type after gelatinization, enzymatic hydrolysis, and retrogradation. QRS4 is a phosphorylated cross-linked starch, with a surface morphology, particle size range, and crystal type similar to QS, but displaying modified thermodynamic properties. QRS5 is a complex of amylose and palmitic acid. It displays typical V-type crystals, mainly composed of long chain molecules and primarily exhibits a block morphology. The noodles prepared by replacing 20 % wheat flour with QS, QRS3 and QRS5 have higher hardness and are suitable for people who like elasticity and chewiness. QRS4 noodles are softer and suitable for people like elderly and infants who prefer soft foods. In conclusion, significant differences were evident between the fine structures, crystal types, physicochemical properties and potential applications of QS and the three QRSs. The results may expand the application of QS and QRS in the food and pharmaceutical industries.


Subject(s)
Chenopodium quinoa , Starch , Humans , Aged , Starch/chemistry , Resistant Starch , Chenopodium quinoa/chemistry , Flour , Triticum , Amylose/chemistry
8.
Environ Monit Assess ; 195(9): 1023, 2023 Aug 07.
Article in English | MEDLINE | ID: mdl-37548802

ABSTRACT

Economic development has rapidly progressed since the implementation of reform and opening up policies, posing significant challenges to sustainable development, especially to vegetation, which plays a crucial role in maintaining ecosystem service functions and promoting green low-carbon transformations. In this study, we estimated the fractional vegetation cover (FVC) in Shandong Province from 2000 to 2020 using the Google Earth Engine (GEE) platform. The spatial and temporal changes in FVC were analyzed using gravity center migration analysis, trend analysis, and geographic detector, and the vegetation changes of different land use types were analyzed to reveal the internal driving mechanism of FVC changes. Our results indicate that vegetation cover in Shandong Province was in good condition during the period 2000 to 2020. The high vegetation cover classes dominated, and overall changes were relatively small, with the center of gravity of vegetation cover generally shifting towards the southwest. Land use type, soil type, population density, and GDP factors had the most significant impact on vegetation cover change in Shandong Province. The interaction of these factors enhanced the effect on vegetation cover change, with land use type and soil type having the highest degree of influence. The observational results of this study can provide data support for the policy makers to formulate new ecological restoration strategies, and the findings would help facilitate the sustainability management of regional ecosystem and natural resource planning.


Subject(s)
Ecosystem , Environmental Monitoring , China , Conservation of Natural Resources , Soil , Sustainable Development
9.
RSC Adv ; 13(17): 11472-11479, 2023 Apr 11.
Article in English | MEDLINE | ID: mdl-37063739

ABSTRACT

Antibiotic-like organic pollutants are harmful to aquatic ecosystems and seriously disrupt the ecological balance. Herein, we propose a simple and versatile method to prepare cobalt-manganese oxides with high specific surface area and abundant oxygen vacancies using low-temperature reduction crystallization, which greatly facilitates the adsorption and electron transfer between the catalyst, PDS, and TC, thus accelerating the degradation of tetracycline (TC). Among them, the degradation efficiency of TC in the CoMn2O4(C)/PDS system was 99.8% in 60 min and the degradation rate remained above 90% after four cycles. The possible degradation mechanism is also discussed, where Co is the main metal active center of the catalyst and Mn plays an auxiliary catalytic role to promote the generation of reactive radicals in PDS through redox interactions between Co and Mn, where SO4 -˙ is the main active species for TC degradation. Finally, the possible degradation pathways of TC are proposed and the toxicity of the intermediates is evaluated. Findings from this work will shed light on the rational design of bimetallic oxide catalysts.

10.
Anal Bioanal Chem ; 414(29-30): 8263-8276, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36201045

ABSTRACT

Dendritic organic molecular gels are a promising class of three-dimensional network compounds. Here, we have synthesized a new type of dendritic organic molecular gel stationary phase (SiO2-G3) by using benzyl alcohol as raw material and dimethyl 5-hydroxyisophthalate as growth unit to synthesize a third-generation organic molecular gel G3, which grafted onto the silica surface by cyanogen chloride (CC). The developed stationary phase not only exhibits high molecular shape selectivity but also has a RPLC/HILIC/IEC mixed-mode characteristic for HPLC due to the ordered structure, the multiple strong π-π stacking interactions and the introduction of a hydrophilic triazine fraction during the grafting process. Compared with a commercial C18 column, the developed column exhibited flexible selectivity, enhanced separation performance and excellent separation of monosubstituted benzene, polycyclic aromatic hydrocarbons (PAHs), positional isomers, nucleosides and nucleobases, benzoic acid and aniline compounds. In addition, the new column provided baseline separation of polycyclic aromatic hydrocarbon contaminants in Yellow River water, verifying its potential for application in the analysis of real samples.


Subject(s)
Polycyclic Aromatic Hydrocarbons , Silicon Dioxide , Silicon Dioxide/chemistry , Chromatography, Liquid , Hydrophobic and Hydrophilic Interactions , Chromatography, High Pressure Liquid/methods , Gels , Polycyclic Aromatic Hydrocarbons/analysis
11.
J Colloid Interface Sci ; 628(Pt A): 448-462, 2022 Dec 15.
Article in English | MEDLINE | ID: mdl-35932681

ABSTRACT

Peroxymonosulfate-based advanced oxidation processes (PMS-AOPs) are effective methods for the degradation of highly toxic and refractory nitrogen-containing heteroatomic pollutants such as benzotriazole (BTA). The construction of catalytic materials with multiple active centers is the key to generating abundant reactive oxygen species (ROS) and achieving high mineralization efficiency in PMS-AOPs. Herein, carbon nanotubes-intercalated cobalt copper bimetallic oxide nanosheets catalyst (CoCuNS@CNTs) was obtained by pyrolysis of two-dimensional (2D) MOF precursor. The degradation rate constant of BTA in CoCuNS@CNTs/PMS system was 4 times higher than that of metal oxide nanosheets catalyst without CNTs, while exhibiting high cycling stability and mineralization efficiency. Serial characterizations demonstrated that CoCu nanosheets was formed by CNTs-induced the directional assembly of metal oxide nanoparticles, which had high graphitization and abundant oxygen vacancies and could greatly facilitated the adsorption and electron transfer between the catalyst, PMS and BTA. Moreover, the doping of Cu species significantly improved PMS utilization and accelerated the Co(III)/Co(II) redox cycle. Both radicals (SO4-• and •OH) and non-radicals (1O2) played a role in CuCoNS@CNTs/PMS system and the contributions of ROS were 72.2%, 11.1% and 16.7%, respectively. Meanwhile, the concentration of key ROS (SO4-•) production increased from 4.76 µM to 8.56 µM compared with cobalt oxide nanosheets (CoNS). Three degradation pathways of BTA were proposed: benzene ring opening, benzene ring hydroxylation and triazole ring dimerization. Finally, the toxicity changes during the degradation process were measured and the toxicity of eleven intermediates was evaluated. This study may provide new insights into the degradation of persistent organic pollutants.


Subject(s)
Environmental Pollutants , Nanotubes, Carbon , Benzene , Cobalt , Copper , Nanotubes, Carbon/toxicity , Nitrogen , Oxides , Oxygen , Peroxides , Persistent Organic Pollutants , Reactive Oxygen Species , Triazoles/toxicity
12.
Chem Commun (Camb) ; 58(49): 6954-6957, 2022 Jun 16.
Article in English | MEDLINE | ID: mdl-35642611

ABSTRACT

Inspired by the working principle of natural spiderweb and long-persistence phosphors, we have synthesized a spiderweb-like nanocomposite in which CoS quantum dots are confined in N-doped carbon frameworks/carbon nanotubes (CNTs). The intimate combination of three-dimensional conductive networks of CoS/CNTs with abundant active sites allows effective capture of sulfate radicals via both physical confinement and chemical bonding and accelerates the redox kinetics significantly. Furthermore, in virtue of the light storing and luminescence behaviors of long-persistence phosphors, the all-weather CoS/CNTs produced can realize an optimum degradation efficiency of 64% under dark conditions. Overall, this work reveals a significant step forward for building a desirable all-weather catalyst with abundant active sites for potential use in degradation under dark conditions.

13.
J Colloid Interface Sci ; 622: 577-590, 2022 Sep 15.
Article in English | MEDLINE | ID: mdl-35526415

ABSTRACT

Environmental H2O is an influential factor in the low-temperature catalytic oxidation of volatile organic compounds (VOCs), and it significantly impacts the reaction process and mechanism. Here, a series of rod-like Cu-Mn oxides were synthesised by pyrolysing Cu/Mn-BTC for acetone oxidation. The results confirm that the formation of multiphase interfaces have more excellent catalytic performance compared to single-phase catalysis. This phenomenon can be attributed to the formation of multiphase interfaces, which resulted in the synthesized catalysts with more active oxygen species and defective sites. The CuMn2Ox catalyst exhibited superior catalytic performance (T90 = 150 °C), high water resistance and long-term stability. Furthermore, in situ diffuse reflectance infrared Fourier transform spectroscopy and thermal desorption-gas chromatography-mass spectrometry results indicated that the degradation pathway of acetone was as follows: acetone ((CH3)2CO*) â†’ enolate complexes ((CH2) = C(CH3) O*) â†’ acetaldehyde ((CH3CHO*) â†’ acetate (CH3COO*) â†’ formate (HCOO*) â†’ CO2 and H2O. At a low-temperature, water vapour dissociated a large number of activated hydroxyl groups on the multiphase interface, which promoted the dissociation of enolate complexes and acetaldehyde species. This composite oxide is a promising catalyst for removing oxygenated VOCs at high humidity.


Subject(s)
Oxides , Volatile Organic Compounds , Acetaldehyde , Acetone , Catalysis , Oxidation-Reduction , Oxides/chemistry , Volatile Organic Compounds/chemistry
14.
Natl Sci Rev ; 8(3): nwaa195, 2021 Mar.
Article in English | MEDLINE | ID: mdl-34691593

ABSTRACT

Identification of the real catalytic site in CO2 reduction reaction (CO2RR) is critical for the rational design of catalysts and the understanding of reactive mechanisms. In this study, the catalytic activity of pyridine-containing materials was for the first time structurally demonstrated in CO2RR by crystalline supramolecular coordination compounds model system. The system consists of three stable supramolecular coordination compounds (Ni-TPYP, Ni-TPYP-1 and Ni-TPP) with different numbers (4, 2 and 0) of active pyridine groups (i.e. uncoordinated pyridine nitrogen atoms). The electrocatalytic test results show that with the decrease of the number of active pyridine groups, the CO2RR performance is gradually reduced, mainly showing the reduction of highest FECO (99.8%, 83.7% and 25.6%, respectively). The crystallographic, experimental and theoretical evidences prove that the CO2RR activity is more likely derived from uncoordinated pyridine nitrogen than the electrocatalytic inert metal nickel in porphyrin center. This work serves as an important case study for the identification of electrocatalytic activity of pyridine-containing materials in CO2RR by simple supramolecular model system.

15.
JACS Au ; 1(2): 212-220, 2021 Feb 22.
Article in English | MEDLINE | ID: mdl-34467285

ABSTRACT

The design of a powerful heterojunction structure and the study of the interfacial charge migration pathway at the atomic level are essential to mitigate the photocorrosion and recombination of electron-hole pairs of CdS in photocatalytic hydrogen evolution (PHE). A temperature-induced self-assembly strategy has been proposed for the syntheses of Prussian blue analogue (PBA)/CdS nanocomposites with beaded structure. The specially designed structure had evenly exposed CdS which can efficiently harvest visible light and inhibit photocorrosion; meanwhile, PBA with a large cavity provided channels for mass transfer and photocatalytic reaction centers. Remarkably, PB-Co/CdS-LT-3 exhibits a PHE rate of 57 228 µmol h-1 g-1, far exceeding that of CdS or PB-Co and comparable to those of most reported crystalline porous material-based photocatalysts. The high performances are associated with efficient charge migration from CdS to PB-Co through CN-Cd electron bridges, as revealed by the DFT calculations. This work sheds light on the exploration of heterostructure materials in efficient PHE.

16.
Nat Commun ; 12(1): 4134, 2021 07 05.
Article in English | MEDLINE | ID: mdl-34226547

ABSTRACT

Junin virus (JUNV) causes Argentine hemorrhagic fever, a debilitating human disease of high mortality rates and a great risk to public health worldwide. Studying the L protein that replicates and transcribes the genome of JUNV, and its regulator Z protein should provide critical clues to identify therapeutic targets for disrupting the life cycle of JUNV. Here we report the 3.54 Å cryo-EM structure of the JUNV L protein complexed with regulator Z protein. JUNV L structure reveals a conserved architecture containing signature motifs found in other L proteins. Structural analysis shows that L protein is regulated by binding of Z protein at the RNA product exit site. Based on these findings, we propose a model for the role of Z protein as a switch to turn on/off the viral RNA synthesis via its interaction with L protein. Our work unveils the mechanism of JUNV transcription, replication and regulation, which provides a framework for the rational design of antivirals for combating viral infections.


Subject(s)
Arenavirus/enzymology , Arenavirus/genetics , Viral Proteins/chemistry , Viral Proteins/genetics , Viral Proteins/metabolism , Animals , Cell Line , Cryoelectron Microscopy , Hemorrhagic Fever, American/virology , Host-Pathogen Interactions , Humans , Junin virus/enzymology , Junin virus/genetics , Models, Molecular , Protein Conformation , RNA, Viral
17.
J Hazard Mater ; 417: 126052, 2021 Sep 05.
Article in English | MEDLINE | ID: mdl-34000702

ABSTRACT

The development of synthetic methods to obtain high value-added mesoporous Al-MCM-41 from a low-cost silicon-aluminum source with low toxicity is an active research topic in solid waste resource utilization. In particular, the controlled synthesis of MCM-41 with a two-level pore distribution is a challenging task. In this work, the synthesis of unimodal and bimodal mesoporous Al-MCM-41s was achieved using acids with different degrees of ionization from coal gasification fine residue (CGFR) as bulk solid waste generated by the coal gasification process. We determined that the degree of acid ionization affected the self-assembly of inorganic/organic species as well as condensation processes, resulting in some changes of the hexagonal mesoscopic structure. The unimodal mesoporous Al-MCM-41 with acetic acid HAc and bimodal mesoporous Al-MCM-41s with an inorganic acid environment (HCl, HNO3 or H2SO4) could be effectively prepared in a controllable manner by the silicon and aluminum source obtained at alkali dissolution time 6 h and crystallization conditions at pH 10.5 and 383 K in 72 h. Moreover, the synthesis of Al-MCM-41-HAc with different SiO2/Al2O3 molar ratios (18-89) could also be realized by different alkali dissolution times. And alkali dissolution time (2-24 h) and the crystallization conditions (pH 4.5-11.5, temperatures 373-393 K, and time 48-96 h) also affected the formation of unimodal and bimodal mesoporous Al-MCM-41-HAc. In addition, the maximum adsorption amount onto bimodal mesoporous Al-MCM-41-H2SO4 (476.19 mg g-1 at 308 K) was larger than that onto unimodal mesoporous Al-MCM-41-HAc (243.90 mg g-1 at 303 K). The mesoporous Al-MCM-41s showed good stability.

18.
Research (Wash D C) ; 2021: 6742715, 2021.
Article in English | MEDLINE | ID: mdl-33860233

ABSTRACT

Amorphous pseudocapacitive nanomaterials are highly desired in energy storage applications for their disordered crystal structures, fast electrochemical dynamics, and outstanding cyclic stability, yet hardly achievable using the state-of-the-art synthetic strategies. Herein, for the first time, high capacitive fiber electrodes embedded with nanosized amorphous molybdenum trioxide (A-MoO3-x) featuring an average particle diameter of ~20 nm and rich oxygen vacancies are obtained via a top-down method using α-MoO3 bulk belts as the precursors. The Jahn-Teller distortion in MoO6 octahedra due to the doubly degenerate ground state of Mo5+, which can be continuously strengthened by oxygen vacancies, triggers the phase transformation of α-MoO3 bulk belts (up to 30 µm long and 500 nm wide). The optimized fibrous electrode exhibits among the highest volumetric performance with a specific capacitance (C V ) of 921.5 F cm-3 under 0.3 A cm-3, endowing the fiber-based weaveable supercapacitor superior C V and E V (energy density) of 107.0 F cm-3 and 9.5 mWh cm-3, respectively, together with excellent cyclic stability, mechanical robustness, and rate capability. This work demonstrates a promising strategy for synthesizing nanosized amorphous materials in a scalable, cost-effective, and controllable manner.

19.
Environ Sci Technol ; 55(8): 5347-5356, 2021 04 20.
Article in English | MEDLINE | ID: mdl-33724005

ABSTRACT

Purposively designing environmental advanced materials and elucidating the underlying reactivity mechanism at the atomic level allows for the further optimization of the removal performance for contaminants. Herein, using well facet-controlled I-Cu2WS4 single crystals as a model transition metal chalcogenide sorbent, we investigated the adsorption performance of the exposed facets toward gaseous elemental mercury (Hg0). We discovered that the decahedron exhibited not only facet-dependent adsorption properties for Hg0 but also recrystallization along the preferential [001] growth direction from a metastable state to the steady state. Besides, the metastable crystals with a predominant exposure of {101} facets dominated the promising adsorption efficiency (about 99% at 75 °C) while the saturated adsorption capacity was evaluated to be 2.35 mg·g-1. Subsequently, comprehensive characterizations and X-ray adsorption fine structure (XAFS), accompanied by density functional theory (DFT) calculations, revealed that it might be owing to the coordinatively unsaturated local environment of W atoms with S defects and the surface relative stability of different facets, which could be affected by the change in surface atom configuration. Hence, the new insight into the facet-dependent adsorption property of transition metal chalcogenide for Hg0 may have important implications, and the atomic-level study directly provides instructions for development and design of highly efficient functional materials.


Subject(s)
Mercury , Adsorption
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