Effects of Central Metal Ion on Binuclear Metal Phthalocyanine-Based Redox Mediator for Lithium Carbonate Decomposition.

Li2CO3 is the most tenacious parasitic solid-state product in lithium-air batteries (LABs). Developing suitable redox mediators (RMs) is an efficient way to address the Li2CO3 issue, but only a few RMs have been investigated to date, and their mechanism of action also remains elusive. Herein, we investigate the effects of the central metal ion in binuclear metal phthalocyanines on the catalysis of Li2CO3 decomposition, namely binuclear cobalt phthalocyanine (bi-CoPc) and binuclear cobalt manganese phthalocyanine (bi-CoMnPc). Density functional theory (DFT) calculations indicate that the key intermediate peroxydicarbonate (*C2O62-) is stabilized by bi-CoPc2+ and bi-CoMnPc3+, which is accountable for their excellent catalytic effects. With one central metal ion substituted by manganese for cobalt, the bi-CoMnPc's second active redox couple shifts from the second Co(II)/Co(III) couple in the central metal ion to the Pc(-2)/Pc(-1) couple in the phthalocyanine ring. In artificial dry air (N2-O2, 78:22, v/v), the LAB cell with bi-CoMnPc in electrolyte exhibited 261 cycles under a fixed capacity of 500 mAh g-1carbon and current density of 100 mA g-1carbon, significantly better than the RM-free cell (62 cycles) and the cell with bi-CoPc (193 cycles).

How Doping Affects the Activity of the Aluminum Oxide Support.

The performance of heteronuclear clusters [AlXO3 ]+ (X=Al, AlO4 , AlMg2 O2 , AlZnO, AlAu2 , Mg, Y, VO, NbO, TaO) in activating methane has been explored by a combination of high-level quantum calculations with reported and supplementary gas-phase experiments. With different dopants in [AlXO3 ]+ , the mechanism, reactivity and selectivity towards methane activation varies accordingly. The classic HAT competes with PCET, depending on the composition of intramolecular interactions. Although the existence of terminal oxygen radical is beneficial for classic HAT, the Alt -C interaction in the [AlXO3 ]+ clusters as enhanced by the strongly electronegative doping groups (X=Al, AlZnO, Mg, Zn, VO, NbO, TaO) favors the PCET process, facilitating C-H bond breaking. In addition, with different dopants, the destiny of the split methyl group varies accordingly. While strong interaction between Alt and CH3 results in the formation of the Alt -C bond, dopants with variable valance may promote the formation of deep-oxidation products like formaldehyde. It has been discussed in detail how to regulate the activity and selectivity of the active center of the catalyst via rational doping.

Methane Activation by [AlFeO3 ]+ : the Hidden Spin Selectivity.

The performance of heteronuclear cluster [AlFeO3 ]+ in activating methane has been explored by a combination of high-level quantum chemical calculations with gas-phase experiments. At room temperature, [AlFeO3 ]+ is a mixture of 7 [AlFeO3 ]+ and 5 [AlFeO3 ]+ , in which two states lead to different reactivity and chemoselectivity for methane activation. While hydrogen extracted from methane is the only product channel for the 7 [AlFeO3 ]+ /CH4 couple, 5 [AlFeO3 ]+ is able to convert this substrate to formaldehyde. In addition, the introduction of an external electric field may regulate the reactivity and product selectivity. The interesting doping effect of Fe and the associated electronic origins are discussed, which may guide one on the design of Fe-involved catalyst for methane conversion.

On the origin of reactivity variation upon sequential ligation: the [Re(Cl)x]+/CH4 (x = 1-3) couples.

The potential of [ReClx]+ (x = 1-3) in activating methane has been explored by using a combination of gas-phase experiments and high-level quantum calculations. When the number of Cl ligands increases, the reactivity towards methane activation varies accordingly. While [ReClx]+ (x = 1-2) are able to dehydrogenate methane by a three-state reactivity scenario, [ReCl3]+ shows inertness towards methane at ambient conditions. Furthermore, the product ion [ClRe(H)CH]+ of the [ReCl]+/CH4 couple could continue to activate methane and liberate molecular dihydrogen but another product ion [Cl2ReCH2]+ is unreactive with methane. Obviously, the nature and the number of ligands make a difference to the reactivity towards methane activation. The associated reaction mechanism and the electron origins for the rather different reactivities are discussed in detail. Finally and more importantly, instructive information concerning the rational design of Re-catalysts for methane conversion is obtained.

Reversed Active Sites Boost the Intrinsic Activity of Graphene-like Cobalt Selenide for Hydrogen Evolution.

Optimizing the hydrogen adsorption Gibbs free energy (ΔGH ) of active sites is essential to improve the overpotential of the electrocatalytic hydrogen evolution reaction (HER). We doped graphene-like Co0.85 Se with sulfur and found that the active sites are reversed (from cationic Co sites to anionic S sites), which contributed to an enhancement in electrocatalytic HER performance. The optimal S-doped Co0.85 Se composite has an overpotential of 108 mV (at 10 mA cm-2 ) and a Tafel slope of 59 mV dec-1 , which exceeds other reported Co0.85 Se-based electrocatalysts. The doped S sites have much higher activity than the Co sites, with a hydrogen adsorption Gibbs free energy (ΔGH ) close to zero (0.067 eV), which reduces the reaction barrier for hydrogen production. This work provides inspiration for optimizing the intrinsic HER activity of other related transition metal chalcogenides.

Significance of saline nasalirrigation for COVID-19 infection: observations and reflections from nursing care of nasopharyngeal carcinoma.

Background: Coronavirus disease 2019 (COVID-19) has placed a tremendous burden on the world's healthcare systems, prompting medical professionals worldwide to diligently research and experiment with treatment methods to prevent infection and alleviate symptoms. Previous studies have shown the potential of nasal irrigation in reducing viral clearance time and alleviating local symptoms of COVID-19. However, views differ regarding its efficacy in improving systemic symptoms. Thus, we sought to examine whether saline nasal irrigation might play a role in treatment and self-care after COVID-19 infection, but further validation is still necessary. Methods: We conducted a retrospective analysis of 468 patients and 51 healthcare personnel concurrently. The participants were grouped based on whether they received saline nasal irrigation. We used χ2 tests and Fisher's exact tests to assess the differences in the rates of COVID-19 infection and the rates of developing a fever after COVID-19 infection among different groups. Additionally, we used independent samples t-tests and Mann-Whitney U tests to evaluate differences in the maximum fever temperature and fever duration among participants with fever in different groups. Results: The rate of developing a fever after COVID-19 infection was lower (37.7%) in the patients who underwent saline nasal irrigation. Among all febrile patients, there was no difference in the highest fever temperature, but patients who underwent saline nasal irrigation had a shorter fever duration (1.72±1.05 days). Additionally, the rate of COVID-19 infection and the rate of developing a fever were higher, and fever symptoms were more severe in the healthcare worker group than in the patient group. Conclusions: Saline nasal irrigation can alleviate symptoms caused by COVID-19 infection.

Significance of chemotherapy for older patients with nasopharyngeal carcinoma in the intensity-modulated radiotherapy era: A propensity score matching analysis.

INTRODUCTION: This study aimed to evaluate the survival and prognosis of older patients with nasopharyngeal carcinoma (NPC) who received intensity-modulated radiotherapy (IMRT) alone versus IMRT plus chemotherapy using propensity score matching (PSM). MATERIALS AND METHODS: We enrolled 841 older patients with NPC aged 60 years and above without metastasis receiving IMRT alone or chemoradiotherapy from 2012 to 2019. The comorbidity was assessed by adult comorbidity evaluation (ACE-27). PSM (1:3 ratio) was conducted between the two treatment groups based on four clinical factors including age, T-stage, N-stage, and ACE-27. Differences in overall survival (OS) and cancer-specific survival (CSS) were analyzed by the Kaplan-Meier method and Cox proportional hazard model. RESULTS: A total of 841 patients with NPC were included in the study, there were 94 patients in the IMRT alone group and 747 patients in the chemoradiotherapy (CRT) group. After a 1:3 ratio PSM, 89 patients underwent IMRT alone and 223 patients underwent CRT. The baseline analysis showed an insignificant difference after PSM (P > 0.05). In multivariate analysis, we found that ACE-27 (≥2) was associated with worse five-year OS and CSS (HR = 1.994, 95%CI: 1.276-3.116, P = 0.002; HR = 1.849, 95%CI: 1164-2.935, P = 0.009, respectively). Chemotherapy was an independent prognosticator of better five-year OS and CSS (HR = 0.333, 95%CI: 0.213-0.552, P < 0.001; HR = 0.327, 95%CI: 0.204-0.524, P < 0.001, respectively). In terms of subgroup analysis, chemotherapy was a statistically beneficial predictor for stage III-IV patients (P < 0.05), but no significant difference in stage II patients (P > 0.05). About the adverse events, the incidence of hepatotoxicity (P = 0.002), neutropenia (P < 0.001), anemia (P < 0.001), and thrombocytopenia (P < 0.001) were significantly higher in the CRT group. DISCUSSION: Combined modality therapy was associated with improved five-year OS and CSS in older adults with stage III-IV NPC, but was not associated with improved survival over IMRT alone in patients with stage II disease. Risk factors including T3-4 disease, positive lymph nodes, ACE-27 score ≥ 2, and IMRT alone were were associated with worse OS and CSS. There was a significantly higher incidence of hepatotoxicity and blood toxicity in the CRT group.

NiSe2/CdS composite nanoflakes photocatalyst with enhanced activity under visible light.

Degrading organic pollutants using a photocatalyst under visible light is one of the effective ways to solve the increasingly serious environmental pollution problem. In this work, we have loaded a small amount of NiSe2 nanoflakes on the surface of CdS using a simple and low-cost solvothermal synthesis method. The samples were characterized with detailed X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), photocurrent, photoluminescence spectrometer (PL), photocatalytic properties, etc. The results show that a 2 mol% load of NiSe2 increases the rate of degradation of Rhodamine B (RhB) to more than twice the original rate (0.01000 min-1 versus 0.00478 min-1). Meanwhile, the sample has excellent stability. The improved photocatalytic properties can be attributed to the face-to-face contact between the nanoflakes, accelerated separation and transfer of photon-generated carriers. This work provides a suitable co-catalyst that can be used to optimize the performance of other photocatalytic materials.