Electrochemistry and Electrochemiluminescence of Coumarin Derivative Microrods: Mechanism Insights.

Organic molecules and related nanomaterials have attracted extensive attention in the realm of electrochemiluminescence (ECL). Herein, a well-known electroluminescence (EL) dopant 2,3,6,7-tetrahydro-1,1,7,7,-tetramethyl-1H,5H,11H-10-(2-benzothiazolyl)quinolizino-[9,9a,1gh] coumarin (C545T) is selected as a new ECL illuminant, which shows a high photoluminescence quantum yield of nearly 100% and excellent ECL performance in the organic phase. For utilizing C545T to achieve ECL detection in aqueous solution, organic microrods of C545T (C545T MRs) were synthesized by a precipitation method. Cyclic voltammetry and differential pulse voltammetry of C545T and C545T MRs in acetonitrile or phosphate buffer showed one reduction and multiple oxidation peaks, suggesting that the multiple charge states of C545T could be produced by continuous electron- or hole-injection processes. The annihilated ECL emission of C545T and C545T MRs was observed using ECL transient technology. In the presence of triethanolamine (TEOA) or potassium persulfate (K2S2O8), C545T MRs can also give bright anodic and cathodic ECL emission at the GCE/water interface. The proposed ECL system not only has multichannel ECL emission but also shows intense yellow emission (569 nm) with a relative ECL efficiency of 0.81 when TEOA was used as a coreactant. Benefiting from the strong ECL emission of the C545T MRs/TEOA system and the quenching effect of dopamine (DA) on ECL, a convenient sensor for DA was developed with high selectivity and sensitivity.

Impact of alternate partial root-zone irrigation on the rhizosphere microbiota of alfalfa plants inoculated with rhizobia.

Water is an important constraint on alfalfa (Medicago sativa) production in arid and semiarid areas, and alternate irrigation in root areas has water-saving potential for alfalfa production. To investigate the impact of alternate partial root-zone irrigation (APRI) on the rhizosphere soil microorganisms of alfalfa, this study subjected alfalfa plants to different irrigation methods and irrigation levels. The growth status and rhizosphere soil microbial community diversity of alfalfa plants under alternate root-zone watering treatment were analyzed through laboratory experiments and high-throughput sequencing. The results showed that at soil moisture levels of 80% field moisture capacity (FMC) and 60% FMC, APRI had no significant impact on the biomass or nodule number of alfalfa. However, 40% FMC significantly reduced the individual plant dry weight, chlorophyll content, and nodule number of the alfalfa plants. APRI increased the relative abundance of Actinomycetes in the alfalfa rhizosphere soil. Moreover, at 60% FMC, the MBC and MBN of rhizosphere, relative abundance of Actinobacteria and unclassified K fungi and Chao 1 index of bacteria significantly increased under APRI treatment. While relative abundance of Ascomycetes and Proteobacteria in the alfalfa rhizosphere significantly reduced under 60% FMC + APRI treatment. In summary, under the same irrigation conditions, APRI did not significantly affect the growth of alfalfa in the short term. And 60%FMC + APRI treatment did significantly affect the groups, structure and diversity of the rhizosphere soil microbial communities.

Rational Design of Non-Covalent Imprinted Polymers Based on the Combination of Molecular Dynamics Simulation and Quantum Mechanics Calculations.

Molecular imprinting is a promising approach for developing polymeric materials as artificial receptors. However, only a few types of molecularly imprinted polymers (MIPs) are commercially available, and most research on MIPS is still in the experimental phase. The significant limitation has been a challenge for screening imprinting systems, particularly for weak functional target molecules. Herein, a combined method of quantum mechanics (QM) computations and molecular dynamics (MD) simulations was employed to screen an appropriate 2,4-dichlorophenoxyacetic acid (2,4-D) imprinting system. QM calculations were performed using the Gaussian 09 software. MD simulations were conducted using the Gromacs2018.8 software suite. The QM computation results were consistent with those of the MD simulations. In the MD simulations, a realistic model of the 'actual' pre-polymerisation mixture was obtained by introducing numerous components in the simulations to thoroughly investigate all non-covalent interactions during imprinting. This study systematically examined MIP systems using computer simulations and established a theoretical prediction model for the affinity and selectivity of MIPs. The combined method of QM computations and MD simulations provides a robust foundation for the rational design of MIPs.

Highly selective separation and purification of lincomycin by macroporous adsorption resin column chromatography.

In this study, lincomycin was successfully purified by macroporous adsorption resin column chromatography using the HZ3 resin. The optimal separation parameters were set as follows: the column bed height was 33 cm, sample loading capacity was 48 mg/mL and flow rate of loading was 1 mL/min. A mixture of 0.02 mol/L of Na2HPO4∙12H2O (pH = 8.5, adjusted using H3PO4) and acetone (80:20, v/v) was used as the eluent. The elution flow rate was maintained at 3 mL/min. Under these parameters, the purity of lincomycin calculated using the standard curve was 99.00 %, with the yield being 97.84 %. This enrichment and separation method of lincomycin is highly regarded owing to its remarkable efficiency and straightforward operation. Thus, the proposed method for the separation and purification of lincomycin holds considerable promise for pharmaceutical applications.

A high-efficiency and selective fluorescent assay for the detection of tetracyclines.

Tetracyclines (TCs) rank second globally in the use of animal infection therapy and animal husbandry as growth promoters among all antibiotics. However, large amounts of TCs residue in food products and more than 75% of TCs are excreted into the environment, causing adverse effects on the ecological system and human health. It has been challenging to simultaneously realize low-cost, rapid, and highly selective detection of TCs. Here, inspired by the fluorogenic reactions between resorcinol and catecholamines, we find the fluorescence quenching ability of tetracycline (TC) and firstly propose a fluorescent "turn-off" detection of TC using dopamine and 4-fluororesorcinol. The optimal reaction condition for the fluorescent assay is investigated and the optimized probe showed a good limit of detection (LOD of 1.7 µM) and a wide linear range (10 µM to 350 µM). Moreover, this fluorescent assay proved to be an effective tool for detecting TC in river, Sprite, and beer samples, which represent the aquatic environments and food and may contain tetracyclines residues. Finally, the high selectivity of the method for TC has been confirmed by eliminating the interference from common substances. The proposed strategy provides a high-efficiency and selective solution for the detection of TCs in environment and food and the application fields of this fluorescent assay could be further expanded in the future.

Computational design and preparation of water-compatible noncovalent imprinted microspheres.

Herein, 2,4-dichlorophenoxyacetic acid (2,4-D) was used as a model template in a rational design strategy to produce water-compatible noncovalent imprinted microspheres. The proposed approach involved computational modelling for screening functional monomers and a simple method for preparing monodisperse and highly cross-linked microspheres. The fabricated non-imprinted polymer (NIP) and 2,4-d-imprinted polymer (2,4-d-MIP) were characterised, and their adsorption capabilities in an aqueous environment were evaluated. Results reveal that the pseudo-second-order kinetics model was appropriate for representing the adsorption of 2,4-D on NIP and 2,4-d-MIP, with R2 values of 0.97 and 0.99, respectively. The amount of 2,4-D adsorbed on 2,4-d-MIP (97.75 mg g-1) was considerably higher than those of phenoxyacetic acid (35.77 mg g-1), chlorogenic acid (9.72 mg g-1), spiramycin (1.56 mg g-1) and tylosin (1.67 mg g-1). Furthermore, it exhibited strong resistance to protein adsorption in an aqueous medium. These findings confirmed the feasibility of the proposed approach, providing a reference for the development of water-compatible noncovalent imprinted polymers.

Essential role of bromodomain proteins in renal cell carcinoma (Review).

Histone alterations are a hallmark of kidney cancer. Histone acetylation modification mediated by bromodomain proteins (BRD) has been indicated to be related to a variety of cancer types and several targeted inhibitors have been proven to be promising modalities for cancer adjuvant therapy. As renal cell carcinoma (RCC) is not sensitive to radiotherapy or chemotherapy, the exploration of effective adjuvant therapies remains an important research direction for advanced RCC. At present, studies on bromodomain family proteins in RCC are limited and the roles of bromodomain family proteins in RCC have remained to be fully elucidated. The present review discussed the role of bromodomain family proteins in RCC, aiming to explore possible potential therapeutic targets of BRD­related drugs in this type of cancer.

Integrated molecular diode as 10 MHz half-wave rectifier based on an organic nanostructure heterojunction.

Considerable efforts have been made to realize nanoscale diodes based on single molecules or molecular ensembles for implementing the concept of molecular electronics. However, so far, functional molecular diodes have only been demonstrated in the very low alternating current frequency regime, which is partially due to their extremely low conductance and the poor degree of device integration. Here, we report about fully integrated rectifiers with microtubular soft-contacts, which are based on a molecularly thin organic heterojunction and are able to convert alternating current with a frequency of up to 10 MHz. The unidirectional current behavior of our devices originates mainly from the intrinsically different surfaces of the bottom planar and top microtubular Au electrodes while the excellent high frequency response benefits from the charge accumulation in the phthalocyanine molecular heterojunction, which not only improves the charge injection but also increases the carrier density.