RSC Advances

He, Shanshan; Yang, Chen; Peng, Sijia; Chen, Chunlai; Zhao, Xin Sheng

doi: 10.1039/c9ra00021fpmid: 35516350

We found that apo DNA methyltransferase M.HhaI under the physiological salt concentration does not possess the structure characterized by X-ray crystallography; instead, it interchanges between prefolded and unfolded states. Only after binding to the substrate, it transforms into a crystal-structure-like state. Flipping rates of its catalytic loop were directly measured.

Cheng, Qiuxia; Qin, Luzhu; Ke, Chunxian; Zhou, Jianen; Lin, Jia; Lin, Xiaoming; Zhang, Gang; Cai, Yuepeng

doi: 10.1039/c9ra02163apmid: 35516295

Four new coordination polymers, {[Zn(3-PBI)(H2O)]·2DMF}n (1), [Cd(3-PBI)(DMF)]n (2), {[Zn4(μ4-O)(4-PBI)3]·3DMF}n (3), {[Cd4(4-PBI)4(H2O)6]·13H2O}n (4), have been constructed from two isomeric flexible multi-carboxylate ligands, 3-H2PBI = 5-(3-(pyridin-3-yl)benzamido)isophthalic acid and 4-H2PBI = 5-(3-(pyridin-4-yl)benzamido)isophthalic acid. Structural analysis reveals that compound 1 is a one-dimensional (1D) ladder-like chain assembled by Zn(ii) ions and 3-PBI2− ligands, which further extend into a 3D supramolecular structure through π⋯π stacking and interlayer (O–H⋯O) hydrogen bonding interactions. In compound 2, Cd2+ metal ions are connected by carboxylate groups to form [Cd2(COO)4] secondary building units (SBUs). The whole framework possesses a quadrilateral channel and constitutes a unique 3D (3,6)-connected rutile net with the Schläfli symbol of (42·610·83)(4·62)2. As for 3, Zn(ii) ions are bridged by one μ4-O and six carboxylate groups to form a tetranuclear [Zn4(μ4-O)(COO)6] cluster, resulting in a rare (3,9)-connected 3D network. Compound 4 has an appealing 2D layered architecture involving two distinct topologies in the crystal structure, stacking in an unusual ABBABB mode (where A represents (4·82) topology and B denotes kgd topology). Moreover, compound 2 is prepared as a support for active selenium through a melt-diffusion method. The obtained Cd-CP/Se electrode can be tested for lithium–selenium batteries and shows an initial capacity of 514 mA h g−1 and a reversible capacity of 200 mA h g−1 at 1C after 500 cycles. The good storage performance of Cd-CP/Se demonstrates it to be a prospective cathode material for lithium–selenium batteries.

Muhammad, Idrees; Sossah, Frederick Leo; Yang, Yang; Li, Dan; Li, Shoujian; Fu, Yongping; Li, Yu

doi: 10.1039/c9ra00632jpmid: 35516343

Outbreaks of cobweb disease are becoming increasingly prevalent globally, severely affecting the quality and yield of Agaricus bisporus. However, cobweb disease-resistant strains are rare, and little is known regarding the biocontrol management of the disease. Here, we isolated a pathogen from a severe outbreak of cobweb disease on A. bisporus in China and identified it as Cladobotryum mycophilum based on morphological characteristics, rDNA sequences, and pathogenicity tests. We then tested 30 A. bisporus strains for cobweb disease resistance by inoculating with C. mycophilum and evaluated the activity of different botanicals. We found that two wild strains of A. bisporus originating from the Tibetan Plateau in China were resistant to cobweb disease, and four commercial strains were susceptible. Yield comparisons of the inoculated and uninoculated strains of A. bisporus with C. mycophilum revealed yield losses of 6–38%. We found that seven botanicals could inhibit C. mycophilum growth in vitro, particularly Syzygium aromaticum, which exhibited the maximum inhibition (99.48%) and could thus be used for the further biocontrol of cobweb disease. Finally, we identified the bioactive chemical constituents present in S. aromaticum that could potentially be used as a treatment for C. mycophilum infection using Fourier transform infrared (FTIR) spectroscopy. These findings provide new germplasm resources for enhancing A. bisporus breeding and for the identification of botanicals for the biocontrol of cobweb disease.

Ge, Mei; Su, Yan; Wang, Han; Yang, Guohui; Zhang, Junfeng

doi: 10.1039/c9ra01825epmid: 35516340

Owing to the great potential applications in information processing and storage, two-dimensional (2D) magnetic materials have recently attracted significant attention. Here, using first-principles calculations, we investigate the electronic and magnetic properties of the van der Waals CrI3/WSe2 heterostructures. We find that after forming heterostructures, monolayer CrI3 undergoes a direct to indirect band gap transition and its gap size is greatly reduced. In particular, the out-plane spin quantization axis of monolayer CrI3 is tuned into in-plane for most stacking configurations of CrI3/WSe2. We further reveal that the transition of the easy magnetization direction is mainly originated from the hybridization between Cr-d and Se-p orbitals. These theoretical results provide a useful picture for the electronic structure and magnetic anisotropy behaviors in vertical CrI3/WSe2 heterostructures.

Ajmi, A.; Karoui, K.; Khirouni, K.; Ben Rhaiem, A.

doi: 10.1039/c9ra01558bpmid: 35516313

In this work, we are interested in the synthesis of monophosphate α-NaCoPO4, β-NaCoPO4 and γ-NaCoPO4 compounds by mechanochemical method and their characterization by X-ray powder diffraction patterns. These compounds are crystallized in the orthorhombic, hexagonal and monoclinic system, in Pnma, P65 and P21/n space groups, respectively. The optical properties were measured by means of the UV-vis absorption spectrometry in order to deduce the absorption coefficient α and optical band gap Eg. The calculated values of the indirect band gaps (Egi) for three samples were estimated at 4.71 eV, 4.63 eV and 3.8 for compounds α, β and γ, respectively. The Tauc model was used to determine the optical gap energy of the synthesized compounds. Then, the results of the dielectric proprieties measured by varying the frequency are described.

Dagdag, Omar; Safi, Zaki; Erramli, Hamid; Cherkaoui, Omar; Wazzan, Nuha; Guo, Lei; Verma, Chandrabhan; Ebenso, E. E.; El Harfi, Ahmed

doi: 10.1039/c9ra01672dpmid: 35516296

Herein, the synthesis, characterization and corrosion inhibition effectiveness of two aromatic epoxy monomers (AEMs) namely, 2-(oxiran-2-yl-methoxy)-N,N-bis(oxiran-2-yl-methyl)aniline (AEM1) and N,N-bis(oxiran-2-ylmethyl)-2-((oxiran-2-ylmethyl) thio)aniline (AEM2), in carbon steel corrosive dissolution in 1 M HCl solution is investigated using computational and experimental techniques. AEM1 and AEM2 were characterized using FT-IR, 1H NMR and 13C NMR spectroscopy techniques. Electrochemical results demonstrated that AEMs act as reasonably good corrosion inhibitors for carbon steel in 1 M HCl medium and their effectiveness followed the sequence: AEM2 (95.4%) > AEM1 (94.3%). A PDP study showed that AEMs act as mixed-type inhibitors with slight anodic predominance. Adsorption of the AEMs obeyed the Langmuir isotherm model. Interactions between AEMs and the metallic surface was further studied using DFT and MD simulations that give several computational parameters such as I, A, EHOMO, ELUMO, ΔE, δ, χ, ρ, σ, η, ΔN and Eads. The experimental and computational results were in good agreement and well complimented each other.

Wang, Jiashuai; Li, Zhe; Yan, Shaocun; Yu, Xue; Ma, Yanqing; Ma, Lei

doi: 10.1039/c9ra01255apmid: 35516309

An improved activated carbon material is synthesized from nostoc flagelliforme algae (NF) using an acid immersing method. The material has more pores and lower internal resistance compared with raw NF. Hydrofluoric acid can effectively decompose cellulose fibers and remove inorganic impurities, giving the carbon materials high mesopore volumes, which makes electrolyte ions rapidly transfer to the active site on the electrode surface. The specific capacitance of the sample was increased from 200 to 283 F g−1 after immersing in hydrofluoric acid. In addition, the symmetric supercapacitor shows an excellent energy density of 22 W h kg−1 at a power density of 80 W kg−1. The capacitance remains at 101.7% after 10 000 cycles. Furthermore, in order to find the relationship between the biochar structure and electrochemical performance in supercapacitors, an artificial neural network (ANN) method is used for studying the complex synergy mechanism. The specific capacitance is modelled using various input factors like aspect ratio (rL/D), cellulose ratio (CL(%)), specific surface area (SBET), pore volume (Vtot), internal resistance (Rs) and so on. The Levenberg–Marquart back propagation algorithm with sigmoid and ReLu active function is adopted to train the model. Random forest is used to analyse the relative importance of every input factor on specific capacitance. Results show that the model can estimate the energy storage with a mean squared error of 4.39 for materials with specific structure. Importance analyses indicate the first three significant variables are SBET, Rs and Vpor. The ANN model can accurately predict the electrical properties of biomass-based carbon materials, and also provide guidance for the selection of energy storage materials in the future.

Wang, Bingshan; Yu, Jinbao; Li, Xiaohong; Yin, Jun; Chen, Meng

doi: 10.1039/c9ra01593kpmid: 35516341

Quasi two-dimensional (2D) mesoporous ZnSnO3 nanomaterials (QTMZNS) were synthesized by a simple template-free hydrothermal method. The as-prepared products were characterized by TEM, SEM, XRD, TG/DTA, and FTIR. The results showed that the precursor was a mixture of Zn5(OH)6(CO3)2 and ZnSnO3 in the hydrothermal process, and the high purity QTMZNS were obtained by calcination combined with subsequent washing of 20 wt% NH4Cl solutions. A possible growth process and mechanism of the quasi 2D mesoporous structure was proposed. Gas sensing properties of QTMZNS were investigated, and the QTMZNS-based sensors exhibited excellent gas sensing properties. When exposed to 100 ppm formaldehyde vapors, the response sensitivity is 45.8, and the concentration limit can reach as low as 0.2 ppm of formaldehyde. All these results are much better than those reported so far, which will have great potential applications for practical air quality monitoring.

Wang, Honghong; Wang, Hui; Jia, Yuting; Zhang, Mai; Li, Zhengping

doi: 10.1039/c9ra01816fpmid: 35516338

Human telomerase is a universal cancer biomarker and a promising anticancer therapeutic target. Sensitive and specific detection of telomerase activity is of great significance for cancer diagnosis and treatment. Up to now, many methods have been established to detect the activity of telomerase, but most of these methods require complex probe design and tedious experimental steps generally including telomere extension reaction, amplification of the extended products and signal detection. Herein, we propose a one-pot method to detect the telomerase activity via RNA FRET probes and RNase H-assisted signal cycling amplification, and the proposed assay can integrate the telomere extension reaction, signal amplification and readout in one step without requirement of amplification of the extended products, which greatly simplifies the experimental design and operation steps. Additionally, the proposed one-pot method has high sensitivity and can unequivocally detect the telomerase activity in as few as 5 cancer cells, which holds great potential in telomerase-related fundamental and clinical studies.

Aguilar, Claudia Marissa; Chairez, Isaac; Rodríguez, Julia Liliana; Tiznado, Hugo; Santillán, Ricardo; Arrieta, Daniel; Poznyak, Tatiana

doi: 10.1039/c9ra02133gpmid: 35516308

This work evaluated the inhibition effect of low molecular weight alcohol (ethanol) on naproxen (NAP) degradation by conventional and catalytic ozonation. The reaction system considered the ethanol as complementary organic matter in water. The conventional ozonation and in the presence of nickel oxide (O3–NiO) achieved 98% NAP degradation during the first 15 min of reaction despite the presence of ethanol. However, NAP degradation presented a delaying effect during the first minutes of treatment with this alcohol. The latter phenomenon indicates that ethanol concentration played a meaningful role in ozonation effectiveness in comparison with the presence of NiO catalyst. The presence of NiO did not generate differences in the byproducts in comparison with conventional ozonation. The intermediates were detected using the Electrospray Ionization Mass Spectrometry technique and have only one aromatic ring in their chemical structure. In samples without ethanol, these byproducts appeared only in the first 5 min of reaction. The TOC study demonstrated the increment of 25% in the mineralization degree with the presence of NiO due to the formation of ·OH species.