Epitaxial Growth of Nanostructured Li2 Se on Lithium Metal for All Solid-State Batteries

Lithium is considered to be the ultimate anode material for high energy-density rechargeable batteries. Recent emerging technologies of all solid-state batteries based on sulfide-based electrolytes raise hope for the practical use of lithium, as it is likely to suppress lithium dendrite growth. However, such devices suffer from undesirable side reactions and a degradation of electrochemical performance. In this work, nanostructured Li2 Se epitaxially grown on Li metal by chemical vapor deposition are investigated as a protective layer. By adjusting reaction time and cooling rate, a morphology of as-prepared Li2 Se is controlled, resulting in nanoparticles, nanorods, or nanowalls with a dominant (220) plane parallel to the (110) plane of the Li metal substrate. Uniaxial pressing the layers under a pressure of 50 MPa for a cell preparation transforms more compact and denser. Dual compatibility of the Li2 Se layers with strong chemical bonds to Li metal and uniform physical contact to a Li6 PS5 Csulfide electrolyte prevents undesirable side reactions and enables a homogeneous charge transfer at the interface upon cycling. As a result, a full cell coupled with a LiCoO2 -based cathode shows significantly enhanced electrochemical performance and demonstrates the practical use of Li anodes with Li2 Se layers for all solid-state battery applications.

Flavonoids mitigate neurodegeneration in aged Caenorhabditis elegans by mitochondrial uncoupling

Dietary supplementation of flavonoids has been shown to reduce the severity of neurodegenerative disorders such as dementia, Parkinson's disease, and Alzheimer's disease by their antioxidant effects. However, their low bioavailabilityin vivo raises the question of how much their antioxidant capacity actually contributes to the mitigating effects. The physicochemical properties of flavonoids suggest they could function as mitochondrial uncouplers. Moreover, mitochondrial uncoupling alleviated neurodegeneration in Caenorhabditis elegans during aging in previous research. Therefore, we investigated whether various flavonoids (fisetin, quercetin, apigenin, chrysin, catechin, and naringenin) could reduce neuronal defects by mitochondrial uncoupling in C. elegans. Both neuronal defects and mitochondrial membrane potential were reduced in aged worms in nearly all of the flavonoid treatments suggesting that flavonoids may reduce neurodegeneration in C. elegans. However, there was no significant reduction of neuronal defects in mitophagy-deficient pink-1/pdr-1 double mutants under flavonoid treatments. These results suggest that flavonoids could function as mitochondrial uncouplers to mitigate neurodegeneration in aged C. elegans, possibly via a PINK1/Parkin mitophagy process.

Lysimachia christinae Hance as an anticancer agent against breast cancer cells

Breast cancer is the most common cancer in women, and metastasis is the leading cause of death in breast cancer patients. Although chemoprevention is widely employed to treat breast cancer, anticancer drugs can cause significant adverse effects. Lysimachia christinae Hance (LH) is a traditional Chinese medicinal plant with diverse therapeutic effects. However, its potential anticancer activity has not been fully investigated in breast cancers to date. Using high-performance liquid chromatography-mass spectrometry, we found that the main constituent of LH extract (LHE) was rutin. Our results indicated that LHE or rutin markedly decreased the proliferation and viability of estrogen receptor (ER)-positive MCF-7 and ER-negative HCC38 human breast cancer cells. LHE treatment induced morphological changes in apoptotic nuclei using 4',6-diamidino-2-phenylindole (DAPI) staining. Annexin V-fluorescein isothiocyanate (FITC) propidium iodide (PI) staining assay revealed that apoptosis significantly increased in both breast cancer cell types after LHE treatment. Additionally, the expression of poly (ADP-ribose) polymerase (PARP), Bcl-2, and phospho-Akt decreased, while that of cleaved PARP and p53 increased, in both cell types. Furthermore, LHE treatment inhibited epithelial-mesenchymal transition (EMT). LHE treatment significantly upregulated E-cadherin level in MCF-7 and HCC38 cells, while vimentin level was downregulated in HCC38 cells. In addition, transwell and wound-healing assays revealed that LHE or rutin inhibited breast cancer cell migration. Overall, these findings demonstrate that LHE is a promising therapeutic agent that acts by promoting apoptosis and reducing cell proliferation, EMT, and cell migration in ER-positive and ER-negative breast cancer cells.

A moderated mediation analysis of occupational stress, presenteeism, and turnover intention among occupational therapists in Korea

OBJECTIVES

Presenteeism is undoubtedly a widespread phenomenon in organizations. Research on presenteeism has been conducted for decades in the broader workforce (eg, nurses, doctors, teachers, police officers). Occupational stress and turnover intention in occupational therapy have been extensively studied. However, the effect of presenteeism on the relationship between occupational stress and resultant turnover intention among occupational therapists is unclear. This study aims to explore the mediating effect of presenteeism and moderating effect of perceived organizational support in the relationship between occupational stress and turnover intention among occupational therapists in Korea.

METHODS

We conducted an individual and cross-sectional analysis of 257 occupational therapists from various health care institutions in Korea. Data were collected and hypotheses were tested via Process macro. Quantitative analyses were conducted with SPSS 26 and LISREL 8.54.

RESULTS

Occupational stress was strongly related to presenteeism, which in turn predicted turnover intention. Presenteeism played a mediating role between occupational stress and turnover intention. Moreover, occupational therapists' perception of organizational support acted as an important mechanism through which presenteeism mediated the relationship between occupational stress and turnover intention.

CONCLUSIONS

This study highlights the need to maximize employee productivity and retain talent by providing managers with insight into the mechanism of presenteeism in relation to occupational stress and turnover intention among occupational therapists in Korea.