Sodium‐ion batteries (SIBs) are still confronted with several major challenges, including low energy and power densities, short‐term cycle life, and poor low‐temperature performance, which severely ...hinder their practical applications. Here, a high‐voltage cathode composed of Na3V2(PO4)2O2F nano‐tetraprisms (NVPF‐NTP) is proposed to enhance the energy density of SIBs. The prepared NVPF‐NTP exhibits two high working plateaux at about 4.01 and 3.60 V versus the Na+/Na with a specific capacity of 127.8 mA h g−1. The energy density of NVPF‐NTP reaches up to 486 W h kg−1, which is higher than the majority of other cathode materials previously reported for SIBs. Moreover, due to the low strain (≈2.56% volumetric variation) and superior Na transport kinetics in Na intercalation/extraction processes, as demonstrated by in situ X‐ray diffraction, galvanostatic intermittent titration technique, and cyclic voltammetry at varied scan rates, the NVPF‐NTP shows long‐term cycle life, superior low‐temperature performance, and outstanding high‐rate capabilities. The comparison of Ragone plots further discloses that NVPF‐NTP presents the best power performance among the state‐of‐the‐art cathode materials for SIBs. More importantly, when coupled with an Sb‐based anode, the fabricated sodium‐ion full‐cells also exhibit excellent rate and cycling performances, thus providing a preview of their practical application.
A high‐voltage sodium‐super‐ion‐conductor‐type cathode significantly enhances the energy density of sodium‐ion batteries. Its low‐strain crystal lattice during the successive (de‐)sodiation and superior Na transport kinetics promise high‐rate capabilities, long‐term cycle life, superior low‐temperature performance, and excellent full‐cell performance, providing a preview of their practical applications.
Covalent organic frameworks (COF) possess a robust and porous crystalline structure, making them an appealing candidate for energy storage. Herein, we report an exfoliated polyimide COF composite ...(P‐COF@SWCNT) prepared by an in situ condensation of anhydride and amine on the single‐walled carbon nanotubes as advanced anode for potassium‐ion batteries (PIBs). Numerous active sites exposed on the exfoliated frameworks and the various open pathways promote the highly efficient ion diffusion in the P‐COF@SWCNT while preventing irreversible dissolution in the electrolyte. During the charging/discharging process, K+ is engaged in the carbonyls of imide group and naphthalene rings through the enolization and π‐K+ effect, which is demonstrated by the DFT calculation and XPS, ex‐situ FTIR, Raman. As a result, the prepared P‐COF@SWCNT anode enables an incredibly high reversible specific capacity of 438 mA h g−1 at 0.05 A g−1 and extended stability. The structural advantage of P‐COF@SWCNT enables more insights into the design and versatility of COF as an electrode.
We prepare a polyimide covalent organic framework composite anode by effective in‐situ condensation of anhydride and amine on the surface of single‐walled carbon nanotubes. The construction of the conductive network accelerates the transport of electron. Dual electroactive sites in the framework, carbonyls and aromatic naphthalene rings, could store more potassium ions by the enolization and π‐K+ effect.
Uncontrolled dendrites growth and serious parasitic reactions in aqueous electrolytes, greatly hinder the practical application of aqueous zinc‐ion battery. On the basis of in situ‐chemical ...construction and performance‐improving mechanism, multifunctional fluoroethylene carbonate (FEC) is introduced into aqueous electrolyte to construct a high‐quality and ZnF2‐riched inorganic/organic hybrid SEI (ZHS) layer on Zn metal anode (ZMA) surface. Notably, FEC additive can regulate the solvated structure of Zn2+ to reduce H2O molecules reactivity. Additionally, the ZHS layer with strong Zn2+ affinity can avoid dendrites formation and hinder the direct contact between the electrolyte and anode. Therefore, the dendrites growth, Zn corrosion, and H2 evolution reaction on ZMA in FEC‐included ZnSO4 electrolyte are highly suppressed. Thus, ZMA in such electrolyte realize a long cycle life over 1000 h and deliver a stable coulombic efficiency of 99.1 % after 500 cycles.
Multifunctional FEC is introduced into aqueous electrolyte to produce a ZnF2‐riched inorganic/organic hybrid SEI (ZHS) layer on Zn metal anode (ZMA) surface. The hydrolysate of FEC can favorably regulate the solvated structure of Zn2+ to restrict the H2O‐related parasitic reactions. The in situ formed ZHS layer not only realize uniform Zn deposition, but also suppresses ZMA corrosion.
A pathology‐adaptive nanosystem, in which nest‐like hosts are built based on nanofibers that are transformed from i.v. injected nanoparticles under the acidic tumor microenvironment. The solid tumor ...is artificially modified by nest‐like hosts readily and firmly, resulting in highly efficient accumulation and stabilization of guest theranostics. This strategy shows great potential for the theranostics delivery to tumors.
Cerebral amyloid β-peptide (Aβ) accumulation resulting from an imbalance between Aβ production and clearance is one of the most important causes in the formation of Alzheimer's disease (AD). In order ...to preserve the maintenance of Aβ homeostasis and have a notable AD therapy, achieving a method to clear up Aβ plaques becomes an emerging task. Herein, we describe a self-destructive nanosweeper based on multifunctional peptide-polymers that is capable of capturing and clearing Aβ for the effective treatment of AD. The nanosweeper recognize and bind Aβ via co-assembly through hydrogen bonding interactions. The Aβ-loaded nanosweeper enters cells and upregulates autophagy thus promoting the degradation of Aβ. As a result, the nanosweeper decreases the cytotoxicity of Aβ and rescues memory deficits of AD transgenic mice. We believe that this resourceful and synergistic approach has valuable potential as an AD treatment strategy.
Aim
To measure the prevalence of compassion fatigue among Chinese clinical nurses and to examine the effects of resilience and self‐efficacy on compassion fatigue.
Design
A cross‐sectional ...descriptive survey was conducted in accordance with the STROBE guidelines.
Methods
Participants were recruited from three tertiary hospitals in central China from October 3 to December 15, 2019, using convenience sampling. Clinical nurses (n = 992) from different nursing departments completed the General Information Questionnaire, Professional Quality of Life Scale, Connor‐Davidson Resilience Scale, and General Perceived Self‐Efficacy Scale. Descriptive statistics, t‐tests, one‐way analysis of variance, Pearson or Spearman's correlation analyses, and multiple linear regression models were used.
Results
Nurses experienced moderate levels of compassion fatigue (burnout and secondary traumatic stress). Resilience and self‐efficacy were significantly negatively correlated with burnout but not with secondary traumatic stress. Linear regression analysis showed that resilience, self‐efficacy, exercise, and physical conditions were the main predictors of burnout. Only physical conditions and marital status significantly predicted secondary traumatic stress.
Conclusion
Nurses are vulnerable to compassion fatigue in China. Resilience and self‐efficacy significantly negatively predicted nurses’ compassion fatigue. Physical conditions, healthy lifestyles, and social support are also important factors for compassion fatigue.
Impact
Our findings can be used to generate targeted intervention and coping strategies for nurses to improve their resilience and self‐efficacy to alleviate compassion fatigue.
Aims and objectives
To investigate the prevalence and extent of burnout on nurses and its association with personal resilience.
Background
With the worldwide shortage of nurses, nurse burnout is ...considered one of the main contributing factors and has been the focus of studies in recent years. Given the well‐documented high level of burnout among nurses, resilience is expected to be a significant predictor of nurse burnout. The association between burnout and resilience has not previously been investigated extensively.
Design
A cross‐sectional survey design was selected.
Methods
A total of 1,061 nurses from six separate three‐level hospitals in Hunan Province, China, returned self‐reported questionnaires from March–June 2015. Data were collected using a socio‐demographic sheet, Maslach Burnout Inventory‐General Survey and the Connor‐Davidson Resilience Scale.
Results
Nurses experienced severe burnout symptoms and showed a moderate level of resilience. Three metrics of burnout had significantly negative correlations with the total score and following variables of resilience. Linear regression analysis showed resilience, especially strength, demographic characteristics (exercise, alcohol use and marital status) and job characteristics (income per month, ratio of patients to nurses, shift work and professional rank) were the main predictors of the three metrics of burnout.
Conclusion
The findings of this study may help nurse managers and hospital administrators to have a better understanding of nurse burnout and resilience. The significantly negative relationship between burnout symptoms and resilience has been demonstrated, and this informs the role of resilience in influencing burnout.
Relevance to clinical practice
Adaptable and effective interventions for improving resilience are needed to relieve nurses’ burnout and reduce workplace stress. Moreover, nurse managers and hospital administrators should establish an effective management system to cultivate a healthy workplace and adopt positive attitudes and harmonious relationships.
Aims and objectives
To investigate burnout among nurses from Australia and China and explore the effects of resilience and turnover intention on nurse burnout between the two countries.
Background
...Nursing shortages and burnout have become serious problems worldwide in recent years. In both developed and developing countries, such as Australia and China, nurse burnout levels are high and therefore attract concern from nurse managers, hospital administrators, nurse educators and researchers. However, few studies have been conducted exploring the differences in burnout and its predictors between Australian and Chinese nurses, particularly investigating the differences in the effect sizes of the predictors.
Design
A comparative cross‐sectional design was employed.
Methods
A total of 100 Australian nurses and 197 Chinese nurses participated in the study. Australian participants completed an online questionnaire, while Chinese participants completed a hardcopy questionnaire. Burnout, resilience and turnover intention were measured.
Results
Burnout was worse for Australian participants than Chinese participants. Only having turnover intention significantly predicted burnout in Australian participants, while low resilience, having turnover intention and low level of regular exercise strongly predicted burnout in Chinese participants. The effect size of turnover intention on burnout in the Australian group was almost twice that of the Chinese group.
Conclusion
The findings of this study show that there are differences in burnout between Australian and Chinese nurses. The effects of resilience and turnover intention on burnout between the two groups are also identified.
Relevance to clinical practice
The differences in nurse burnout and the effects of resilience and turnover intention on burnout should be better understood by nurse managers from Australia and China. Moreover, developing effective strategies relevant to their own country to reduce nurse burnout is recommended.
Aqueous zinc metal batteries have garnered unprecedented attention owing to their high theoretical specific capacity, appropriate redox potential, and remarkable sustainability. Nevertheless, the ...intractable issues induced by the notorious Zn dendrite growth and serious interfacial side reactions significantly impede their large‐scale utilization. Inducing Zn to electrodeposit through parallel arrangement mode is critical to realizing dendrite‐free Zn metal anodes (ZMAs). To realize this purpose, a unique polymeric molecular design strategy through chemically grafting a thin polyanthraquinone (PAQ) overlayer on the Zn surface in the manner of spontaneous polymerization reaction of anthraquinone diazonium tetrafluoroborate (AQN2+BF4−) is proposed firstly. Impressively, thus‐derived PAQ overlayer as an artificial protective layer can constrain the Zn2+ ions 2D diffusion and homogenize the electric field and Zn2+ ions concentration distribution, further guiding preferential growth along the Zn(002) plane. Assisted by the PAQ overlayer, the dendrite growth, H2 evolution reaction, and Zn corrosion on ZMAs are suppressed effectively. Accordingly, such polymeric molecular modified ZMAs ensure a remarkably high Coulombic efficiency of 99.7% at 4 mA cm−2 and achieve a long cycling lifespan up to 1750 h at 1 mA cm−2 and superior rate capability. This work provides a new insight into designing an interface protective layer for achieving highly stable ZMAs.
A unique polymeric molecular design strategy through chemical grafting of a thin polyanthraquinone overlayer on the Zn anode surface in the manner of spontaneous polymerization reaction of anthraquinone diazonium tetrafluoroborate (AQN2+BF4−) is first proposed to constrain Zn2+ 2D diffusion and realize the oriented growth of (002) crystal plane, then successfully suppressing the dendrite growth and H2 evolution reaction.
Tim-3, a member of the novel Tim (T cell immunoglobulin and mucin domain) family, has been reported to negatively regulate the immune responses against viral infection and had implications for ...autoimmune disease. However, the nature and role of Tim-3(+) CD4 T cells in human tumors remain largely unknown. In the present study, we characterized Tim-3(+) CD4 T cells in 100 specimens from human hepatocellular, cervical, colorectal and ovarian carcinoma patients. Compared with peripheral blood and nontumor-infiltrating lymphocytes, the lymphocytes isolated from the corresponding tumor tissues of hepatocellular, cervical, colorectal and ovarian carcinoma patients contained significantly greater proportion of Tim-3(+) CD4 T cells. The majority of tumor-derived Tim-3(+) CD4 T cells exhibited an impaired capacity to produce IFN-γ and IL-2, but expressed higher levels of CD25, Foxp3, CTLA-4 and GITR than their Tim-3(-) CD4 T cell counterparts. In contrast, most Tim-3(+) CD4 T cells isolated from the paired nontumor tissues and peripheral blood did not express these molecules. Moreover, tumor-derived Tim-3(+) CD4 T cells, but not tumor-derived Tim-3(-) CD4 T cells, significantly suppressed the proliferation of autologous CD8(+) T cells in vitro. Notably, multi-color immunofluorescence and confocal microscopy demonstrated that Tim-3(+)Foxp3(+)CD4(+) cells were preferentially distributed in the tumor nest rather than the peritumoral stroma of hepatocellular carcinoma. Together, our data indicate that Tim-3-expressing CD4 T cells in human tumors could represent the functional regulatory T cells which contribute to the formation of the immune-suppressive tumor micromilieu.
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