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N-protonation for numerous fluorophores is widely known as an efficient switch for the fluorescence turn-on/off in acidic conditions, which has been applied in various scenarios that involve pH monitoring. Yet the universal mechanism for fluorescence regulation through N-protonation is still elusive. Herein, the excited state deactivation processes are systematically investigated for a series of nitrogen-containing fluorescent probes through theoretical approaches. Two types of mechanisms for the complex fluorescent phenomena by N-protonation are concluded: one is through the regulation for the transition to a ππ* twisted intramolecular charge transfer (TICT) state; the other one applies for the case when nonradiative decay pathway is predominant by a dark nπ* state, which is also accompanied by an evident structural twisting and can be regarded as another kind of TICT state. More generally, the formation of the TICT state is closely related to the conjugated π-electrons on the single bond that links the acceptor and donor part of fluorophores, which provides a simple strategy for evaluating the occurrence of the TICT process. The current contributions can bring novel insights for the rational design of functional fluorophores that involve TICT process in the excited states., (© 2023 Wiley-VCH GmbH.)

Objective: To investigate the effect of Traditional Chinese Medicine (TCM) acupuncture combined with western medicine in the treatment of neck, shoulder, lumbar and leg pain and its influence on the degree of pain, motor functions and inflammatory factor levels., Methods: In this retrospective study, 86 patients with neck, shoulder, lumbar and leg pain treated in Department of Orthopedics and Traumatology, Hangzhou Fuyang Hospital of TCM from June 2019 to June 2022 were selected as the study subjects. According to different treatment methods, these patients were divided into an observation group (n=43) and a control group (n=43). Patients from the control group were treated with conventional western medicine, while those from the observation group were treated with combination of traditional Chinese medicine acupuncture (Acupuncture + Fumigation with Collaterals-Dredging Decoction) and western medicine. Patients in both groups were treated for 4 weeks continuously. The treatment effect, visual analogue scale (VAS) score, limb motor function scale (Fugl-Meyer) score, cervical function score, daily living ability score, the levels of inflammatory factors including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP) were recorded and compared between two groups., Results: The effective rate of patients in the observation group was 93.02%, which was significantly higher than 76.74% in the control group (P<0.05). There was no significant difference in the term of Fugl-Meyer score, VAS score and levels of inflammatory factors before treatment between two groups (all P>0.05). After treatment, the VAS score and the levels of IL-6, TNF-α and CRP in both of groups significantly decreased in contrast to before treatment. The Fugl-Meyer score after treatment in both of groups was significantly increased in contrast to before treatment. Compared with those after treatment in control group, the VAS score and the levels of IL-6, TNF-α and CRP after treatment in the observation group were obviously lower, while the Fugl-Meyer score in the observation group was significantly higher (all P<0.05)., Conclusion: TCM acupuncture combined with western medicine has a good therapeutic effect on neck, shoulder, lumbar and leg pains, which can effectively relieve the pain, improve motor function and reduce the inflammatory reactions in patients. The combined treatment has clinical application values and is worth promoting., Competing Interests: None., (AJTR Copyright © 2023.)

We performed QM/MM simulations to investigate excess-electron attachment to four aqueous DNA nucleotide anions (dRT - ). The negative QM/MM vertical electron affinities (-0.86 to -0.59 eV) reveal that aqueous dRT - anions improbably capture the excess electron near 0 eV. Comparing with the calculations in the gas phase and without the background charges, it can be found that first-shell water molecules have a larger contribution to the promotion of the ability of the excess-electron capture and the bulk-water polarization has a small effect on vertical electron affinities. The phosphate group hampers the attachment of the very low-energy excess electron to aqueous dRT - . The large adiabatic electron affinities (1.45-1.96 eV) and vertical detachment energies (1.92-2.44 eV) reveal that stable dRT 2- dianions could be formed after dRT - anions catch the higher-energy excess electron (>0.59 eV). We computed the energy changes in the dRT 2- structural relaxations. The QM-region conformational changes cause small energy alterations (-0.28 to 0.35 eV). The QM/MM energy decreases are 2.31-2.73 eV which mainly come from QM computations (3.49-4.00 eV) embedded in the background charges. The analysis of excess-electron distributions indicates that the polarization of bulk water and structural relaxations of dianions induce the excess-electron redistributions in the QM region and produce large QM-energy decreases. The MM energy changes are -1.27 to -1.11 eV for four aqueous dianions. The negative values demonstrate that the energy of the MM region would increase in dRT 2- structural relaxations. In contrast with the values of the polarized QM computations, about 30% of the energy released by the QM region is transferred to bulk water in the MM region. The large energy dissipation probably suppresses DNA damage by the low-energy electron.

The specific host-guest interactions in the corresponding complexes of K + and NH 4 + with typical crown ethers were investigated by using FTIR and ultrafast IR spectroscopies. The counteranions, i.e., SCN - , were employed as a local vibrational probe to report the structural dynamics of the complexation. It was found that the vibrational relaxation dynamics of the SCN - was strongly affected by the cations confined in the cavities of the crown ethers. The time constant of the vibrational population decay of SCN - in the complex of NH 4 + with the 18-crown-6 was determined to be 6 ± 2 ps, which is ∼30 times faster than that in the complex of K + with the crown ethers. Control experiments showed that the vibrational population decay of SCN - depended on the size of the cavities of the crown ethers. A theoretical calculation further indicated that the nitrogen atom of SCN - showed preferential coordination to the K + ions hosted by the crown ethers, while the NH 4 + can form hydrogen bonds with the oxygen atoms in the studied crown ethers. The geometric constraints formed in the complex of crown ethers can cause a specific interaction between the NH 4 + and SCN - , which can facilitate the intermolecular vibrational energy redistribution of the SCN - .