Synthesis and Application of Specific N2H4 Fluorescent Probes with AIE Effect Based on Pyrazole Structure

Two fluorescent probes, Y1-2 were synthesized from 2-acetonaphthone, 4-acetylbiphenyl, and phenyl hydrazine by Vilsmeier-Haack reaction and Knoevenagel condensation. Their recognition efficacies for N2H4 were tested by UV-visible absorption spectroscopy and fluorescence emission spectroscopy. The recognition mechanism were studies by density-functional theory calculations, and the effect of pH on N2H4 recognition was also studied. The results showed that the probe Y1-2 has high selectivity and a low detection limit for N2H4, and the recognition of N2H4 can be accomplished at physiological pH. The probes have had obvious aggregation-induced luminescence effect, large Stokes shift, high sensitivity, and can be successfully applied to live cell imaging.

Bis-chalcone Fluorescent Probe for Hydrazine Ratio Sensing in Environment and Organism

In this paper, four novel hydrazine fluorescent probes X1-X4 with bis-chalcone structure were designed and synthesized. Through the measurement of its optical properties, it is found that it can quickly identify hydrazine, high sensitivity, low detection limit, and good anti-interference ability. The recognition of hydrazine by probes X1-X4 is not affected in the pH range of 4-10, X2 has the highest sensitivity, and the detection limit is as low as 0.336 × 10-7 M. Through Gaussian quantization calculation of probe molecules and their reaction products with hydrazine, it is speculated that the recognition mechanism is the closure of intramolecular charge transfer effect. In addition, the cytotoxicity and imaging of HeLa cells were tested, which showed that probes X1-X4 could be used to detect hydrazine in cells.

Adsorption of perfluoroalkyl and polyfluoroalkyl substances (PFASs) from aqueous solution - A review

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) have gained increasingly global attention in recent years. Due to their unique amphiphilic properties and stability, PFASs are recognized as highly persistent, toxic, and environmentally bioaccumulative. Among several physicochemical technologies, adsorption has been extensively used and proved to be an effective method for removing PFASs from aqueous environment. In this review article, the technical feasibility of the use of different adsorbents, such as activated carbon, ion exchange resins, minerals, molecularly imprinted polymer (MIP), carbon nanotubes (CNTs), and a wide range of potentially low-cost biosorbents, for PFASs removal from water or wastewater is critically reviewed. The evaluation and comparison of their PFASs sorption behavior in terms of kinetics and isotherms is presented. The mechanisms involved in PFASs adsorption processes, such as diffusion, electrostatic interaction, hydrophobic interaction, ion exchange and hydrogen bond, are discussed. The effects of the parameters variability on sorption process are highlighted. Based on the literature reviewed, a few recommendations for future research on PFASs adsorption are also elaborated. Capsule: The adsorption behavior and mechanisms of perfluoroalkyl and polyfluoroalkyl substances (PFASs) on various adsorbents are reviewed.

Controllable assembly of Cu(ii) coordination compounds based on a flexible zwitterionic benzimidazole–dicarboxylate ligand: synthesis, structural diversity, reversible SCSC transformation and magnetic properties

The reversible SCSC transformation of a paddle-wheel cluster to a 1D linear polymer could be accomplished.

[Spectroscopic studies on interaction of bovine hemoglobin and realgar nanoparticles]

In the present paper, the interaction of bovine hemoglobin (BHb) and realgar nanoparticles has been investigated by ultraviolet-visible (UV-Vis) and fluorescence spectroscopy. The Soret band of oxygen-BHb at 406 nm shifted to 413 nm, and its absorption intensity decreased gradually after adding realgar nanoparticles. The Soret band decreases gradually with the increasing the amount of realgar NPs, suggesting the detachment of some heme chromophores from their matrixes in BHb. The red-shift of characteristic peak leads to be conjecture that the arsenic of realgar combined with the oxygen of BHb. The oxygen-BHb was deoxidated by realgar nanoparticles, and the surface binding induces conformation change of BHb from the high-affinity R state to the low-affinity T state. The fluorescence intensity of BHb is quenched by realgar nanoparticles when its concentration gradually increased. The analysis of Stern-Volmer equation revealed that the mechanism was a static quenching procedure. The order of the magnitude of binding constant k was 10(9), obtained from the calculation of UV-Vis and fluorescence spectra.

Isolation and characterization of polycyclic aromatic hydrocarbon-degrading Mycobacterium isolates from soil

Bioremediation of soils contaminated with wood preservatives containing polycyclic aromatic hydrocarbons (PAHs) is desired because of their toxic, mutagenic, and carcinogenic properties. Creosote wood preservative-contaminated soils at the Champion International Superfund Site in Libby, Montana currently undergo bioremediation in a prepared-bed land treatment unit (LTU) process. Microbes isolated from these LTU soils rapidly mineralized the (14)C-labeled PAH pyrene in the LTU soil. Gram staining, electron microscopy, and 16S rDNA-sequencing revealed that three of these bacteria, JLS, KMS, and MCS, were Mycobacterium strains. The phylogeny of the 16S rDNA showed that they were distinct from other Mycobacterium isolates with PAH-degrading activities. Catalase and superoxide dismutase (SOD) isozyme profiles confirmed that each isolate was distinct from each other and from the PAH-degrading mycobacterium, Mycobacterium vanbaalenii sp. nov, isolated from a petroleum-contaminated soil. We find that dioxygenase genes nidA and nidB are present in each of the Libby Mycobacterium isolates and are adjacent to each other in the sequence nidB-nidA, an order that is unique to the PAH-degrading mycobacteria.

Controlled ovulation in the marmoset monkey (Callithrix jacchus) with human chorionic gonadotropin following prostaglandin-induced luteal regression

Controlled induction of ovulation in the marmoset monkey was attempted with a single injection of human chorionic gonadotropin (hCG; 50 IU) given on day 7 after prostaglandin-induced luteal regression. Animals given hCG (n = 12) ovulated within a 2-day period (days 9 and 10 after prostaglandin) compared with a 4-day period (days 9 to 12) in the control group (n = 12). The mean interval to ovulation was similar in both groups. There was no difference in the timing of the preovulatory estradiol (E2) peak between groups, although E2 levels on the day of hCG injection were lower than in controls on the day of the onset of the luteinizing hormone surge. All animals given hCG ovulated and 11 of 12 became pregnant. Ten of 11 embryos recovered surgically from six of these animals were normal blastocysts; 5 of the remaining 6 animals carried pregnancies to term. The results are of practical importance for experiments involving follicular and oocyte maturation and the collection and transfer of embryos.