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The host-guest complex of water-soluble phosphate salt pillar[5]arene (PP5A) and cationic fluorescent dye acridine orange (AO) was constructed, and studied with ultraviolet spectrum (UV), infrared absorption spectrum (IR), molecular fluorescence spectroscopy (MFS), and nuclear magnetic resonance (NMR) spectra (1H NMR and NOESY). And then, the effect of pH and two surfactants, including sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) on the fluorescence intensity of AO/PP5A complex system were investigated. Finally, the complexation mode and energy of PP5A with AO and CTAB were calculated by molecular docking. The results showed that AO and PP5A formed a 1:1 host-guest complex. PP5A reduced or quenched the fluorescence intensity of AO in the pH range of 3~11. The addition of SDS and CTAB did not affect the fluorescence intensity of AO/PP5A complex significantly. The fluorescence changes generated by AO and PP5A complexation can provide a theoretical basis for the design of fluorescence sensors.

An inclusion complex of naringenin (NAR) and β-cyclodextrin (βCD) was prepared with ultrasonication. Powder X-ray diffraction (XRD) and infrared absorption spectroscopy (IR) indicated that the inclusion complex formed had some new physical/chemical properties. 1H NMR and ROESY spectroscopy revealed that the stable supramolecular inclusion complex was formed by having the benzene ring of NAR introduced into the big end of the βCD. The formation processes of NAR/βCD inclusion complex were also studied by quantum chemical calculations. It was revealed that enthalpy and hydrogen bonding weak interaction force were the driving forces behind the formation. The optimal inclusion mode obtained from energy gap and binding energy analyses were consistent with the most inclusive mode obtained from molecular docking analysis and the NMR results. These results were further confirmed by ONIOM calculation.

The article discusses the impact of the COVID-19 pandemic on nurse burnout and retention, highlighting the high levels of burnout and intention to leave among nurses. It emphasizes the need for healthcare organizations and policymakers to implement interventions to support nurses' mental health and wellbeing. The study calls for addressing systemic factors contributing to burnout and improving working conditions for nurses to retain experienced staff and maintain quality of care. Additionally, it suggests longitudinal research on burnout evolution during the pandemic and the importance of using validated measures for meaningful comparisons across studies and settings. [Extracted from the article]

Achieving control over symmetry breaking of completely achiral components in the aqueous phase is a significant challenge in supramolecular chemistry. Herein, we demonstrate that it is possible to construct chiral nanoassemblies by introducing metal ions (Zn 2+ , Fe 3+ , Al 3+ , Cu 2+ , and Ca 2+ ) into completely achiral azobenzene amphiphiles with key structural factors in the pure aqueous phase. It is found that the coordination interactions, π-π stacking, hydrophilic and hydrophobic interactions, hydrogen bonding, and electrostatic interactions are crucial to the metal-ion-induced symmetry breaking of completely achiral building blocks. This study may provide an intriguing model system for constructing chiral assemblies based on completely achiral molecules.

Competing Interests: There are no conflicts of interest.

A novel fluorescent probe, amino-pillar[5]arene (APA), was prepared via a green, effective, and convenient synthetic method, which was characterized by nuclear magnetic resonance (NMR), infrared (IR), and high-resolution mass spectrometry. The fluorescence sensing behavior of the APA probe toward 22 metal ions in aqueous solutions were studied by fluorescence spectroscopy. The results showed that APA could be used as a selective fluorescent probe for the specificity detection of Au 3+ ions. Moreover, the detection characteristics were investigated by fluorescence spectral titration, pH effect, fluorescence competitive experiments, Job's plot analysis, 1 H NMR, and IR. The results indicated that detection of Au 3+ ions by the APA probe could be achieved in the range of pH 1-13.5 and that other coexisting metal ions did not cause any marked interference. The titration analysis results indicated that the fluorescence intensity decreased as the concentration of Au 3+ ions increased, with an excellent correlation ( R 2 = 0.9942). The detection limit was as low as 7.59 × 10 -8 mol·L -1 , and the binding ratio of the APA probe with Au 3+ ions was 2:1. Therefore, the APA probe has potential applications for detecting Au 3+ ions in the environment and in living organisms., Competing Interests: The authors declare no competing financial interest., (Copyright © 2019 American Chemical Society.)