Factors associated with burnout among frontline nurses in the post-COVID-19 epidemic era: a multicenter cross-sectional study.

BACKGROUND: The COVID-19 pandemic has significantly increased the risk of burnout among frontline nurses. However, the prevalence of burnout and its associated factors in the post-pandemic era remain unclear. This research aims to investigate burnout prevalence among frontline nurses in the post-pandemic period and pinpoint associated determinants in China. METHODS: From April to July 2023, a cross-sectional study was carried out across multiple centers, focusing on frontline nurses who had been actively involved in the COVID-19 pandemic. The data collection was done via an online platform. The Maslach Burnout Inventory-Human Services Survey was utilized to evaluate symptoms of burnout. A multivariable logistic regression analysis was used to pinpoint factors associated with burnout. RESULTS: Of the 2210 frontline nurses who participated, 75.38% scored over the cut-off for burnout. Multivariable logistic regression revealed that factors like being female [odds ratio (OR) = 0.41, 95%CI = 0.29-0.58] and exercising 1-2 times weekly[OR = 0.53, 95%CI = 0.42-0.67] were protective factors against burnout. Conversely, having 10 or more night shifts per month[OR = 1.99, 95%CI = 1.39-2.84], holding a master's degree or higher[OR = 2.86, 95% CI = 1.59-5.15], poor health status[OR = 2.43, 95% CI = 1.93-3.08] and [OR = 2.82, 95%CI = 1.80-4.43], under virus infection[OR = 7.12, 95%CI = 2.10-24.17], and elevated work-related stress[OR = 1.53, 95% CI = 1.17-2.00] were all associated with an elevated risk of burnout. CONCLUSION: Our findings indicate that post-pandemic burnout among frontline nurses is influenced by several factors, including gender, monthly night shift frequency, academic qualifications, weekly exercise frequency, health condition, and viral infection history. These insights can inform interventions aimed at safeguarding the mental well-being of frontline nurses in the post-pandemic period.

Engineering Ultrafine NiFe-LDH into Self-Supporting Nanosheets: Separation-and-Reunion Strategy to Expose Additional Edge Sites for Oxygen Evolution.

Here, a strategy is reported to prepare Ni-Fe layered double hydroxide (NiFe-LDH) with abundant exposed edge planes for enhanced oxygen evolution reaction (OER). The edge-to-edge assembly of ultrafine NiFe-LDH directed by graphite-like carbon is performed through a one-step hydrothermal process to form self-supporting nanosheet arrays (named NiFe-LDH/C), in which ascorbic acid is employed as the carbon precursor to control both the platelet size and the assembly mode of NiFe-LDH. Benefiting from the unique structural engineering, NiFe-LDH/C can not only achieve a fast surface reconstruction into the highly active γ-phase structure, but also exposes abundant active edge sites, thus leading to a superior OER performance with the overpotential as low as 234 mV at a current density of 50 mA cm-2 . Furthermore, density functional theory (DFT) calculations reveal that the unsaturated Fe-sites and the bridge-sites connecting Ni and Fe atoms, which only exist on the edge planes of NiFe-LDH, are the main active centers responsible for promoting the intrinsic OER activity. This work provides a specific and valuable reference for the rational design of high-quality electrocatalysts through structural engineering for renewable energy applications.

The df-d Dative Bonding in a Uranium-Cobalt Heterobimetallic Complex for Efficient Nitrogen Fixation.

Single transition-metal site catalysts with s-, p-, or d-block atom anchor for nitrogen fixation have been extensively studied, and yet the studies of the f-block atom anchor are rarely reported. Thus, we investigate the feasibility of using a newly synthesized U-Co complex featuring a single CoI site coordinated by tetrakis(phophinoamide) and an UIV anchor for N2-to-NH3 conversion by theoretical modeling. We characterize the evolution of oxidation states of U and Co along the reaction pathways from ab initio density matrix renormalization group (DMRG) calculations, and we find that the variation of the Co → U dative bond is correlated with the changes of oxidation states. Both uranium and cobalt can serve as electron reservoirs to facilitate breaking the N-N bond. Our study demonstrates the viability of metal → metal dative bonds, particularly the df-d one, for the reduction of N2 to NH3, and thus, this opens up a new avenue to the rational design of efficient catalyst for nitrogen fixation.

Surface Single-Cluster Catalyst for N2-to-NH3 Thermal Conversion.

The ammonia synthesis from N2 is of vital importance, with imitating biological nitrogen fixation attracted much interest. Herein, we investigate the catalytic mechanisms of N2-to-NH3 thermal conversion on the singly dispersed bimetallic catalyst Rh1Co3/CoO(011), and find that the preferred pathway is an associative mechanism analogous to the biological process, in which alternating hydrogenations of the N2 occur, with H2 activation on both metal sites. We propose that the singly dispersed bimetallic M1An catalyst, in which the doped metal atom M substitutes an oxygen atom on the oxide surface of metal A, serves as a new surface single-cluster catalyst (SCC) design platform for the biomimetic N2-to-NH3 thermal conversion. The catalytic ability of M1An catalyst is attributed to both the charge buffer capacity of doped metal M and the complementary role of synergic metal A in catalysis. Our work provides insights and guidelines for further optimizing the M1An catalyst.

Efficient Nitrogen Fixation via a Redox-Flexible Single-Iron Site with Reverse-Dative Iron → Boron σ Bonding.

Model systems of the FeMo cofactor of nitrogenase have been explored extensively in catalysis to gain insights into their ability for nitrogen fixation that is of vital importance to the human society. Here we investigate the trigonal pyramidal borane-ligand Fe complex by first-principles calculations, and find that the variation of oxidation state of Fe along the reaction path correlates with that of the reverse-dative Fe → B bonding. The redox-flexibility of the reverse-dative Fe → B bonding helps to provide an electron reservoir that buffers and stabilizes the evolution of Fe oxidation state, which is essential for forming the key intermediates of N2 activation. Our work provides insights for understanding and optimizing homogeneous and surface single-atom catalysts with reverse-dative donating ligands for efficient dinitrogen fixation. The extension of this kind of molecular catalytic active center to heterogeneous catalysts with surface single-clusters is also discussed.

Mechanistic Insights into the Directed Hydrogenation of Hydroxylated Alkene Catalyzed by Bis(phosphine)cobalt Dialkyl Complexes.

The mechanism of directed hydrogenation of hydroxylated alkene catalyzed by bis(phosphine)cobalt dialkyl complexes has been studied by DFT calculations. The possible reaction channels of alkene hydrogenation catalyzed by catalytic species (0T, 0P, and 0) were investigated. The calculated results indicate that the preferred catalytic activation processes undergo a 1,2 alkene insertion. 0P and 0 prefer the ß hydrogen elimination mechanism with an energy barrier of 9.5 kcal/mol, and 0T prefers the reductive elimination mechanism with an energy barrier of 11.0 kcal/mol. The second H2 coordination in the σ bond metathesis mechanism needs to break the agostic H2-ßC bond of metal-alkyl intermediates (21P and 21T), which owns the larger energetic span compared to the reductive elimination. This theoretical study shows that the most favorable reaction pathway of alkene hydrogenation is the ß hydrogen elimination pathway catalyzed by the planar (dppe)CoH2. The hydrogenation activity of Co(II) compounds with redox-innocent phosphine donors involves the Co(0)-Co(II) catalytic mechanism.

Identification of potential crucial genes and therapeutic targets for epilepsy.

BACKGROUND: Epilepsy, a central neurological disorder, has a complex genetic architecture. There is some evidence suggesting that genetic factors play a role in both the occurrence of epilepsy and its treatment. However, the genetic determinants of epilepsy are largely unknown. This study aimed to identify potential therapeutic targets for epilepsy. METHODS: Differentially expressed genes (DEGs) were extracted from the expression profiles of GSE44031 and GSE1834. Gene co-expression analysis was used to confirm the regulatory relationship between newly discovered epilepsy candidate genes and known epilepsy genes. Expression quantitative trait loci analysis was conducted to determine if epilepsy risk single-nucleotide polymorphisms regulate DEGs' expression in human brain tissue. Finally, protein-protein interaction analysis and drug-gene interaction analysis were performed to assess the role of DEGs in epilepsy treatment. RESULTS: The study found that the protein tyrosine phosphatase receptor-type O gene (PTPRO) and the growth arrest and DNA damage inducible alpha gene (GADD45A) were significantly upregulated in epileptic rats compared to controls in both datasets. Gene co-expression analysis revealed that PTPRO was co-expressed with RBP4, NDN, PAK3, FOXG1, IDS, and IDS, and GADD45A was co-expressed with LRRK2 in human brain tissue. Expression quantitative trait loci analysis suggested that epilepsy risk single-nucleotide polymorphisms could be responsible for the altered PTPRO and GADD45A expression in human brain tissue. Moreover, the protein encoded by GADD45A had a direct interaction with approved antiepileptic drug targets, and GADD45A interacts with genistein and cisplatin. CONCLUSIONS: The results of this study highlight PTPRO and GADD45A as potential genes for the diagnosis and treatment of epilepsy.

Vacancy Defects Inductive Effect of Asymmetrically Coordinated Single-Atom Fe─N3 S1 Active Sites for Robust Electrocatalytic Oxygen Reduction with High Turnover Frequency and Mass Activity.

The development of facile, efficient synthesis method to construct low-cost and high-performance single-atom catalysts (SACs) for oxygen reduction reaction (ORR) is extremely important, yet still challenging. Herein, an atomically dispersed N, S co-doped carbon with abundant vacancy defects (NSC-vd) anchored Fe single atoms (SAs) is reported and a vacancy defects inductive effect is proposed for promoting electrocatalytic ORR. The optimized catalyst featured of stable Fe─N3 S1 active sites exhibits excellent ORR activity with high turnover frequency and mass activity. In situ Raman, attenuated total reflectance surface enhanced infrared absorption spectroscopy reveal the Fe─N3 S1 active sites exhibit different kinetic mechanisms in acidic and alkaline solutions. Operando X-ray absorption spectra reveal the ORR activity of Fe SAs/NSC-vd catalyst in different electrolyte is closely related to the coordination structure. Theoretical calculation reveals the upshifted d band center of Fe─N3 S1 active sites facilitates the adsorption of O2 and accelerates the kinetics process of *OH reduction. The abundant vacancy defects around the Fe─N3 S1 active sites balance the OOH* formation and *OH reduction, thus synergetically promoting the electrocatalytic ORR process.

CO assisted N2 functionalization activated by a dinuclear hafnium complex: a DFT mechanistic exploration.

In this paper, the reaction mechanisms of CO assisted N(2) cleavage and functionalization activated by a dinuclear hafnium complex are studied using a density function theory (DFT) method. Several key intermediates (Ia, Ib, Ic and Id) with axial/equatorial N=C=O coordination structures are found to be of importance along reaction pathways of CO assisted N(2) functionalization, which could provide a profound theoretical insight into the C-N bond formation and N-N bond cleavage. There are two different attack directions to insert the first CO molecule into the Hf-N bonds of the dinuclear hafnium complex, which lead to C-N bond formation. The calculated results imply that CO insertion into the Hf(1)-N(3) bond (Path A1) reacts more easily than that into the Hf(2)-N(3) bond (Path A3). But for the insertion of the second CO insertion to give 2A, there are two possibilities (Path A1 and Path A2) according to this insertion being after/before N-N bond cleavage. Two pathways (Path A1 and Path A2) are proved to be possible to form final dinitrogen functionalized products (oxamidide 2A, 2B and 2C) in this study, which explain the formation of different oxamidide isomers in CO assisted N(2) functionalization activated by a dinuclear hafnium complex.

Anxiety prevalence and associated factors among frontline nurses following the COVID-19 pandemic: a large-scale cross-sectional study.

Introduction: Nurses are more likely to experience anxiety following the coronavirus 2019 epidemic. Anxiety could compromise nurses' work efficiency and diminish their professional commitment. This study aims to investigate nurses' anxiety prevalence and related factors following the pandemic in multiple hospitals across China. Methods: An online survey was conducted from April 16 to July 3, 2023, targeting frontline nurses who had actively participated in China. Anxiety and depression symptoms were assessed using the Self-rating Anxiety Scale and the Self-rating Depression Scale (SDS), respectively. Multivariable logistic regression analysis was employed to identify factors linked with anxiety. Results: A total of 2,210 frontline nurses participated in the study. Overall, 65.07% of participants displayed clinically significant anxiety symptoms. Multivariable logistic regression revealed that nurses living with their families [2.52(95% CI: 1.68-3.77)] and those with higher SDS scores [1.26(95% CI: 1.24-1.29)] faced an elevated risk of anxiety. Conversely, female nurses [0.02(95% CI: 0.00-0.90)] and those who had recovered from infection [0.05(95%CI: 0.07-0.18)] demonstrated lower rates of anxiety. Discussion: This study highlights the association between SDS score, gender, virus infection, living arrangements and anxiety. Frontline nurses need to be provided with emotional support to prevent anxiety. These insights can guide interventions to protect the mental well-being of frontline nurses in the post-pandemic period.

Comprehensive analyses identify potential biomarkers for encephalitis in HIV infection.

Human immunodeficiency virus encephalitis (HIVE) is a severe neurological complication after HIV infection. Evidence shows that genetic factors play an important role in HIVE. The aim of the present study was to identify new potential therapeutic targets for HIVE. Differentially expressed gene (DEG), functional annotation and pathway, and protein-protein interaction analyses were performed to identify the hub genes associated with HIVE. Gene co-expression analysis was carried out to confirm the association between the hub genes and HIVE. Finally, the role of the hub genes in HIVE therapy was evaluated by conducting drug-gene interaction analysis. A total of 20 overlapping DEGs closely related to HIVE were identified. Functional annotation and pathway enrichment analysis indicated that the markedly enriched DEG terms included ion transport, type II interferon signaling, and synaptic signaling. Moreover, protein-protein interaction analysis revealed that 10 key HIVE-related genes were hub genes, including SCN8A, CDK5R2, GRM5, SCN2B, IFI44L, STAT1, SLC17A7, ISG15, FGF12, and FGF13. Furthermore, six hub genes were co-expressed with HIVE-associated host genes in human brain tissue. Finally, three hub genes (STAT1, ISG15, and SCN2B) interacted with several inflammation-associated drugs. These findings suggested that SCN8A, CDK5R2, GRM5, SCN2B, IFI44L, STAT1, SLC17A7, ISG15, FGF12, and FGF13 may be new targets for diagnosis and therapy of HIVE.

Construction of N, P Co-Doped Carbon Frames Anchored with Fe Single Atoms and Fe2 P Nanoparticles as a Robust Coupling Catalyst for Electrocatalytic Oxygen Reduction.

A coupling catalyst of highly dispersed N, P co-doped carbon frames (NPCFs) anchored with Fe single atoms (SAs) and Fe2 P nanoparticles (NPs) is synthesized by a novel in situ doping-adsorption-phosphatization strategy for the electrocatalytic oxygen reduction reaction (ORR). The optimized Fe SAs-Fe2 P NPs/NPCFs-2.5 catalyst shows a superior ORR activity and stability in 0.5 m H2 SO4 and 0.1 m KOH, respectively. Theoretical calculations reveal a synergistic effect, in that the existence of Fe2 P weakens the adsorption of ORR intermediates on active sites and lowers the reaction free energy. The doped P atoms with a strong electron-donating ability elevate the energy level of Fe-3d orbitals and facilitate the adsorption of O2 . The active Fe atoms exist in a low oxidation state and are less positively charged, and they serve as an electron reservoir capable of donating and releasing electrons, thus improving the ORR activity. Operando and in situ characterization results indicate that the atomically dispersed FeN4 /FeP coupled active centers in the Fe SAs-Fe2 P NPs/NPCFs-2.5 catalyst are characteristic of the different catalytic mechanisms in acidic and alkaline media. This work proposes a novel idea for constructing coupling catalysts with atomic-level precision and provides a strong reference for the development of high-efficiency ORR electrocatalysts for practical application.

Heterogeneous Fe3 single-cluster catalyst for ammonia synthesis via an associative mechanism.

The current industrial ammonia synthesis relies on Haber-Bosch process that is initiated by the dissociative mechanism, in which the adsorbed N2 dissociates directly, and thus is limited by Brønsted-Evans-Polanyi (BEP) relation. Here we propose a new strategy that an anchored Fe3 cluster on the θ-Al2O3(010) surface as a heterogeneous catalyst for ammonia synthesis from first-principles theoretical study and microkinetic analysis. We have studied the whole catalytic mechanism for conversion of N2 to NH3 on Fe3/θ-Al2O3(010), and find that an associative mechanism, in which the adsorbed N2 is first hydrogenated to NNH, dominates over the dissociative mechanism, which we attribute to the large spin polarization, low oxidation state of iron, and multi-step redox capability of Fe3 cluster. The associative mechanism liberates the turnover frequency (TOF) for ammonia production from the limitation due to the BEP relation, and the calculated TOF on Fe3/θ-Al2O3(010) is comparable to Ru B5 site.

Substituent effects and chemoselectivity of the intramolecular Buchner reaction of diazoacetamide derivatives catalyzed by the di-Rh(ii)-complex.

A density functional theory (DFT) study was performed to reveal that the substituent effects in the α-site have an effect on the chemoselectivity of the intramolecular Buchner reaction of diazoacetamide catalyzed by Rh2(OAc)4. The substituent effect is investigated considering five different groups (Z = -Me, -OMe, -H, -CN and -C(O)Me) in the substrates. The substituent group in the α-site changes the electronegativity of the C-atom in carbene and affects the chemoselectivity. The basis of chemoselectivity is the distribution of products that was analyzed by DFT calculations. The barrier energy of the favorable pathway is clearly lower than that of the other pathways. Nucleophilic substituent groups, such as -H, -OMe and -Me, are regarded as electron-donating groups, which increase the electropositivity of the C-atom in carbene compounds and improve the reactivity of the aromatic addition reaction. Electrophilic substituent groups, such as -CN and -C(O)Me, are regarded as electron-withdrawing groups, which decrease the electropositivity of the C-atom in carbene compounds and favor the C-H activation step. The computational results showed that the main product is cycloheptatriene when Z = -H/-OMe. The main product is ß-lactam when the substituent group is -CN/-C(O)Me. When the substituent group is -Me, the products are a mixture of γ-lactams, ß-lactams and cycloheptatriene.

Bent and planar structures of µ-η²:η²-N2 dinuclear early transition metal complexes.

This work studied the bent and planar structures of M2N2 cores of a series of dinuclear early transition-metal complexes (M = Zr, Hf, Nb, Ta, Mo and W) containing a side-on bridging dinitrogen ligand using DFT method. The calculated results propose three key factors favoring a bent structure: (1) the availability of a single electron in the metal centers which leads to the bonding interaction between two metal atoms, (2) no remarkable steric effect around the metal centers, and (3) the cis conformation of the ligands in the dinitrogen dinuclear complexes. In addition, the bent and planar structures of M2N2 could be transformed into each other if the steric hindrance was slight.