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1.
Nature ; 593(7857): 67-73, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33953412

RESUMEN

Transition metal (oxy)hydroxides are promising electrocatalysts for the oxygen evolution reaction1-3. The properties of these materials evolve dynamically and heterogeneously4 with applied voltage through ion insertion redox reactions, converting materials that are inactive under open circuit conditions into active electrocatalysts during operation5. The catalytic state is thus inherently far from equilibrium, which complicates its direct observation. Here, using a suite of correlative operando scanning probe and X-ray microscopy techniques, we establish a link between the oxygen evolution activity and the local operational chemical, physical and electronic nanoscale structure of single-crystalline ß-Co(OH)2 platelet particles. At pre-catalytic voltages, the particles swell to form an α-CoO2H1.5·0.5H2O-like structure-produced through hydroxide intercalation-in which the oxidation state of cobalt is +2.5. Upon increasing the voltage to drive oxygen evolution, interlayer water and protons de-intercalate to form contracted ß-CoOOH particles that contain Co3+ species. Although these transformations manifest heterogeneously through the bulk of the particles, the electrochemical current is primarily restricted to their edge facets. The observed Tafel behaviour is correlated with the local concentration of Co3+ at these reactive edge sites, demonstrating the link between bulk ion-insertion and surface catalytic activity.

2.
Analyst ; 149(9): 2542-2555, 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38632960

RESUMEN

Scanning electrochemical cell microscopy (SECCM) has emerged as a transformative technology for electrochemical materials characterisation and the study of single entities, garnering global adoption by numerous research groups. While details on the instrumentation and operational principles of SECCM are readily available, the growing need for practical guidelines, troubleshooting strategies, and a systematic overview of applications and trends has become increasingly evident. This tutorial review addresses this gap by offering a comprehensive guide to the practical application of SECCM. The review begins with a discussion of recent developments and trends in the application of SECCM, before providing systematic approaches to (and the associated troubleshooting associated with) instrumental set up, probe fabrication, substrate preparation and the deployment of environmental (e.g., atmosphere and humidity) control. Serving as an invaluable resource, this tutorial review aims to equip researchers and practitioners entering the field with a comprehensive guide to essential considerations for conducting successful SECCM experiments.

3.
Proc Natl Acad Sci U S A ; 118(47)2021 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-34782464

RESUMEN

Regulatory B cells (Breg cells) that secrete IL-10 or IL-35 (i35-Breg) play key roles in regulating immunity in tumor microenvironment or during autoimmune and infectious diseases. Thus, loss of Breg function is implicated in development of autoimmune diseases while aberrant elevation of Breg prevents sterilizing immunity, exacerbates infectious diseases, and promotes cancer metastasis. Breg cells identified thus far are largely antigen-specific and derive mainly from B2-lymphocyte lineage. Here, we describe an innate-like IL-27-producing natural regulatory B-1a cell (i27-Breg) in peritoneal cavity and human umbilical cord blood. i27-Bregs accumulate in CNS and lymphoid tissues during neuroinflammation and confers protection against CNS autoimmune disease. i27-Breg immunotherapy ameliorated encephalomyelitis and uveitis through up-regulation of inhibitory receptors (Lag3, PD-1), suppression of Th17/Th1 responses, and propagating inhibitory signals that convert conventional B cells to regulatory lymphocytes that secrete IL-10 and/or IL-35 in eye, brain, or spinal cord. Furthermore, i27-Breg proliferates in vivo and sustains IL-27 secretion in CNS and lymphoid tissues, a therapeutic advantage over administering biologics (IL-10, IL-35) that are rapidly cleared in vivo. Mutant mice lacking irf4 in B cells exhibit exaggerated increase of i27-Bregs with few i35-Bregs, while mice with loss of irf8 in B cells have abundance of i35-Bregs but defective in generating i27-Bregs, identifying IRF8/BATF and IRF4/BATF axis in skewing B cell differentiation toward i27-Breg and i35-Breg developmental programs, respectively. Consistent with its developmental origin, disease suppression by innate i27-Bregs is neither antigen-specific nor disease-specific, suggesting that i27-Breg would be effective immunotherapy for a wide spectrum of autoimmune diseases.


Asunto(s)
Enfermedades Autoinmunes/inmunología , Enfermedades del Sistema Nervioso Central/inmunología , Interleucina-27/metabolismo , Enfermedades Neuroinflamatorias/inmunología , Animales , Linfocitos B Reguladores/inmunología , Diferenciación Celular , Encefalitis , Factores Reguladores del Interferón , Interleucina-10 , Ratones , Uveítis/inmunología
4.
J Korean Med Sci ; 39(3): e27, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38258362

RESUMEN

BACKGROUND: Coronary artery disease patients undergoing percutaneous coronary intervention (PCI) often exhibit reduced left ventricular ejection fraction (LVEF). However, the impact of LV dysfunction status in conjunction with platelet reactivity on clinical outcomes has not been previously investigated. METHODS: From the multicenter PTRG-DES (Platelet function and genoType-Related long-term prognosis in DES-treated patients) consortium, the patients were classified as preserved-EF (PEF: LVEF ≥ 50%) and reduced-EF (REF: LVEF< 5 0%) group by echocardiography. Platelet reactivity was measured using VerifyNow P2Y12 assay and high platelet reactivity (HPR) was defined as PRU ≥ 252. The major adverse cardiac and cerebrovascular events (MACCEs) were a composite of death, myocardial infarction, stent thrombosis and stroke at 5 years after PCI. Major bleeding was defined as Bleeding Academic Research Consortium bleeding types 3-5. RESULTS: A total of 13,160 patients from PTRG-DES, 9,319 (79.6%) patients with the results of both PRU and LVEF were analyzed. The incidence of MACCE and major bleeding was higher in REF group as compared with PEF group (MACCEs: hazard ratio [HR] 2.17, P < 0.001, 95% confidence interval [CI] 1.85-2.55; major bleeding: HR 1.78, P < 0.001, 95% CI 1.39-2.78). The highest rate of MACCEs was found in patients with REF and HPR, and the difference between the groups was statistically significant (HR 3.14 in REF(+)/HPR(+) vs. PEF(+)/HPR(-) group, P < 0.01, 95% CI 2.51-3.91). The frequency of major bleeding was not associated with the HPR in either group. CONCLUSION: LV dysfunction was associated with an increased incidence of MACCEs and major bleeding in patients who underwent PCI. The HPR status further exhibited significant increase of MACCEs in patients with LV dysfunction in a large, real-world registry. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04734028.


Asunto(s)
Stents Liberadores de Fármacos , Intervención Coronaria Percutánea , Disfunción Ventricular Izquierda , Humanos , Volumen Sistólico , Intervención Coronaria Percutánea/efectos adversos , Pronóstico , Función Ventricular Izquierda , Hemorragia/etiología
5.
J Adv Nurs ; 2024 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-39315744

RESUMEN

AIM: To examine the association between nurses' insomnia, presenteeism and care left undone and explore the mediating effect of presenteeism on the relationship between insomnia and care left undone among nurses in acute care hospitals, applying a dynamic model of presenteeism and absenteeism. DESIGN: A cross-sectional design. METHODS: A secondary data analysis was conducted using online survey data collected in January 2023. Participants were 1154 registered nurses who provided direct nursing care to patients in tertiary or general hospitals (hospitals with 300 or more beds) in South Korea. Poisson regression analysis was used to examine the association between nurses' insomnia, presenteeism and care left undone. Generalised structural equation modelling was performed to examine the mediating effect of presenteeism on the relationship between insomnia and care left undone. RESULTS: The prevalence of insomnia was 15.3%. More than half of the participants (63.7%) reported experiencing presenteeism in the past 4 weeks. All reported at least one nursing care left undone during their last shift. Insomnia and presenteeism were positively associated with care left undone, and presenteeism mediated the relationship between insomnia and care left undone among nurses in acute care hospitals. CONCLUSION: Nurses experienced insomnia and presenteeism, related to higher rates of care left undone. Nurses' insomnia had a direct effect on care left undone and an indirect effect through presenteeism. IMPLICATIONS FOR THE PROFESSION: Nurse managers and administrators need to make greater efforts to reduce insomnia and presenteeism among nurses, thereby reducing care left undone and improving patient safety in acute care settings. IMPACT: Nurse managers and administrators should consider proactive interventions to address nurses' insomnia and foster a workplace with healthy systems and culture to reduce sleep disturbance and presenteeism, which can effectively decrease care left undone. REPORTING METHOD: STROBE guidelines. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution.

6.
J Adv Nurs ; 2024 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-39306857

RESUMEN

AIM(S): To investigate job characteristic profiles based on the job demands-resources (JD-R) model and the association between job characteristic profiles and presenteeism. DESIGN: Cross-sectional study. METHODS: Data were collected from shift nurses in South Korea in January 2023 using an online survey. This study included 544 nurses working in tertiary and general hospitals in South Korea. The participants were classified into four job characteristic profiles based on the JD-R model using latent profile analysis. Multiple logistic and linear regression analyses were performed to examine the association between job characteristic profiles and presenteeism. RESULTS: Four profiles were derived from the latent profile analysis: low strain-low motivation, high strain-low motivation, low strain-high motivation and high strain-high motivation. The high strain-low motivation, low strain-high motivation and high strain-high motivation groups were 1.74, 1.37 and 3.51 times more likely to experience presenteeism than the low strain-low motivation group respectively. The number of days worked while sick and the level of reduced job productivity was also the highest in the high strain-high motivation group. In addition, general health, multimorbidities and insomnia were significant factors affecting presenteeism, number of days worked while sick and productivity loss among shift nurses. CONCLUSIONS: This study found that even with higher levels of job resources, work environments with high levels of job demands were associated with higher rates of presenteeism. IMPACT: Study findings suggest that various strategies are needed to improve the physical and mental health of shift nurses, and create a healthy organisational environment by reducing excessive job demands to reduce presenteeism and increase productivity. REPORTING METHOD: STROBE guidelines. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution.

7.
Int J Mol Sci ; 25(14)2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39063066

RESUMEN

Loss of the inner blood-retinal barrier (BRB) integrity is a main feature of ocular diseases such as diabetic macular edema. However, there is a lack of clarity on how inner BRB function is modulated within the diabetic retina. The current study examined whether eucalyptol inhibited inner BRB destruction and aberrant retinal angiogenesis in 33 mM glucose-exposed human retinal microvascular endothelial (RVE) cells and db/db mice. This study further examined the molecular mechanisms underlying endothelial dysfunction including retinal endoplasmic reticulum (ER) stress and angiopoietin (Ang)/Tie axis in conjunction with vascular endothelial growth factor (VEGF). Eucalyptol is a naturally occurring monoterpenoid and an achiral aromatic component of many plants including eucalyptus leaves. Nontoxic eucalyptol reduced the production of amyloid-ß (Aß) protein in glucose-loaded RVE cells and in diabetic mice. This natural compound blocked apoptosis of Aß-exposed RVE cells in diabetic mouse eyes by targeting ER stress via the inhibition of PERK-eIF2α-ATF4-CHOP signaling. Eucalyptol promoted activation of the Ang-1/Tie-2 pathway and dual inhibition of Ang-2/VEGF in Aß-exposed RVE cells and in diabetic eyes. Supply of eucalyptol reversed the induction of junction proteins in glucose/Aß-exposed RVE cells within the retina and reduced permeability. In addition, oral administration of eucalyptol reduced vascular leaks in diabetic retinal vessels. Taken together, these findings clearly show that eucalyptol inhibits glucose-induced Aß-mediated ER stress and manipulates Ang signaling in diabetic retinal vessels, which ultimately blocks abnormal angiogenesis and loss of inner BRB integrity. Therefore, eucalyptol provides new treatment strategies for diabetes-associated RVE defects through modulating diverse therapeutic targets including ER stress, Ang-1/Tie-2 signaling, and Ang-2/VEGF.


Asunto(s)
Diabetes Mellitus Experimental , Retinopatía Diabética , Estrés del Retículo Endoplásmico , Eucaliptol , Transducción de Señal , Animales , Estrés del Retículo Endoplásmico/efectos de los fármacos , Eucaliptol/farmacología , Ratones , Retinopatía Diabética/metabolismo , Retinopatía Diabética/tratamiento farmacológico , Retinopatía Diabética/patología , Transducción de Señal/efectos de los fármacos , Humanos , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/tratamiento farmacológico , Factor A de Crecimiento Endotelial Vascular/metabolismo , Células Endoteliales/metabolismo , Células Endoteliales/efectos de los fármacos , Barrera Hematorretinal/metabolismo , Barrera Hematorretinal/efectos de los fármacos , Masculino , Apoptosis/efectos de los fármacos , Angiopoyetina 1/metabolismo , Ratones Endogámicos C57BL , Vasos Retinianos/metabolismo , Vasos Retinianos/efectos de los fármacos , Vasos Retinianos/patología
8.
Nurs Crit Care ; 29(5): 923-930, 2024 09.
Artículo en Inglés | MEDLINE | ID: mdl-38516768

RESUMEN

BACKGROUND: Delirium commonly occurs in paediatric patients with acute critical illness and negatively affects clinical outcomes. Variations in delirium knowledge levels and its management have been noted among nurses. AIMS: This study investigated nurses' experiences and knowledge levels regarding paediatric delirium. Additionally, we aimed to assess the gap between knowledge levels and practical experiences with paediatric delirium. STUDY DESIGN: This cross-sectional descriptive study conveniently sampled paediatric nurses from a university hospital in South Korea between September 2022 and March 2023. Nursing experiences with paediatric delirium and delirium knowledge levels were measured using structured survey questionnaires. Delirium knowledge was scored 0 to 47, and higher scores indicated higher levels of delirium-related knowledge. Data were analysed using descriptive statistics and presented as mean, standard deviation, frequency and percentage. RESULTS: A total of 127 paediatric nurses participated in this study; 40.2% had experience with 1-5 delirium cases in the previous year, and 86.6% (n = 110) had never used assessment tools for paediatric delirium assessment. The mean total delirium knowledge score was 34.45 ± 5.4; the mean scores of knowledge regarding aetiology, signs and symptoms and nursing management of delirium were 8.93 ± 1.31, 13.24 ± 2.81 and 12.3 ± 2.7, respectively. Interventions associated with a lower level of delirium-related knowledge and a lower performance rate included avoiding restraint use and maintaining hydration and electrolyte levels. Interventions associated with a higher level of delirium-related knowledge but a lower rate of performance comprised providing orientation, offering emotional support, allowing participants to stay with family members and administering medications to manage delirium. CONCLUSIONS: Although nurses working in paediatric units exhibited high rate of delirium nursing care, there was the gap between their delirium-related knowledge and practice. Nurses need to be aware of the insufficient part of delirium care, and paediatric delirium education should be reinforced. RELEVANCE TO CLINICAL PRACTICE: Preventing, assessing and systematically managing paediatric delirium is crucial, and considering the study results, delirium education among nurses is needed.


Asunto(s)
Competencia Clínica , Delirio , Conocimientos, Actitudes y Práctica en Salud , Humanos , Delirio/enfermería , Estudios Transversales , Femenino , Masculino , República de Corea , Encuestas y Cuestionarios , Adulto , Niño , Enfermería de Cuidados Críticos , Enfermería Pediátrica , Personal de Enfermería en Hospital/psicología , Personal de Enfermería en Hospital/educación
9.
Small ; 19(40): e2303442, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37269212

RESUMEN

Understanding the solid electrolyte interphase (SEI) formation and (de)lithiation phenomena at silicon (Si) electrodes is key to improving the performance and lifetime of Si-based lithium-ion batteries. However, these processes remain somewhat elusive, and, in particular, the role of Si surface termination merits further consideration. Here, scanning electrochemical cell microscopy (SECCM) is used in a glovebox, followed by secondary ion mass spectrometry (SIMS) at identical locations to study the local electrochemical behavior and associated SEI formation, comparing Si (100) with a native oxide layer (SiOx /Si) and etched with hydrofluoric acid (HF-Si). HF-Si shows greater spatial electrochemical heterogeneity and inferior lithiation reversibility than SiOx /Si. This is attributed to a weakly passivating SEI and irreversible lithium trapping at the Si surface. Combinatorial screening of charge/discharge cycling by SECCM with co-located SIMS reveals SEI chemistry as a function of depth. While the SEI thickness is relatively independent of the cycle number, the chemistry - particularly in the intermediate layers - depends on the number of cycles, revealing the SEI to be dynamic during cycling. This work serves as a foundation for the use of correlative SECCM/SIMS as a powerful approach to gain fundamental insights on complex battery processes at the nano- and microscales.

10.
Acc Chem Res ; 55(3): 241-251, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-35020363

RESUMEN

ConspectusElectrochemical reduction of the greenhouse gas CO2 offers prospects for the sustainable generation of fuels and industrially useful chemicals when powered by renewable electricity. However, this electrochemical process requires the use of highly stable, selective, and active catalysts. The development of such catalysts should be based on a detailed kinetic and mechanistic understanding of the electrochemical CO2 reduction reaction (eCO2RR), ideally through the resolution of active catalytic sites in both time (i.e., temporally) and space (i.e., spatially). In this Account, we highlight two advanced spatiotemporal voltammetric techniques for electrocatalytic studies and describe the considerable insights they provide on the eCO2RR. First, Fourier transformed large-amplitude alternating current voltammetry (FT ac voltammetry), as applied by the Monash Electrochemistry Group, enables the resolution of rapid underlying electron-transfer processes in complex reactions, free from competing processes, such as the background double-layer charging current, slow catalytic reactions, and solvent/electrolyte electrolysis, which often mask conventional voltammetric measurements of the eCO2RR. Crucially, FT ac voltammetry allows details of the catalytically active sites or the rate-determining step to be revealed under catalytic turnover conditions. This is well illustrated in investigations of the eCO2RR catalyzed by Bi where formate is the main product. Second, developments in scanning electrochemical cell microscopy (SECCM) by the Warwick Electrochemistry and Interfaces Group provide powerful methods for obtaining high-resolution activity maps and potentiodynamic movies of the heterogeneous surface of a catalyst. For example, by coupling SECCM data with colocated microscopy from electron backscatter diffraction (EBSD) or atomic force microscopy, it is possible to develop compelling correlations of (precatalyst) structure-activity at the nanoscale level. This correlative electrochemical multimicroscopy strategy allows the catalytically more active region of a catalyst, such as the edge plane of two-dimensional materials and the grain boundaries between facets in a polycrystalline metal, to be highlighted. The attributes of SECCM-EBSD are well-illustrated by detailed studies of the eCO2RR on polycrystalline gold, where carbon monoxide is the main product. Comparing SECCM maps and movies with EBSD images of the same region reveals unambiguously that the eCO2RR is enhanced at surface-terminating dislocations, which accumulate at grain boundaries and slip bands. Both FT ac voltammetry and SECCM techniques greatly enhance our understanding of the eCO2RR, significantly boosting the electrochemical toolbox and the information available for the development and testing of theoretical models and rational catalyst design. In the future, it may be possible to further enhance insights provided by both techniques through their integration with in situ and in operando spectroscopy and microscopy methods.

11.
Int J Mol Sci ; 24(2)2023 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-36675135

RESUMEN

Osteoporosis is evident in postmenopausal women and is an osteolytic disease characterized by bone loss that further increases the susceptibility to bone fractures and frailty. The use of complementary therapies to alleviate postmenopausal osteoporosis is fairly widespread among women. Edible Cirsium setidens contains various polyphenols of linarin, pectolinarin, and apigenin with antioxidant and hepatoprotective effects. This study aimed to determine whether Cirsium setidens water extracts (CSEs), the component linarin, and its aglycone acacetin blocked ovariectomy (OVX)-induced bone loss. This study employed OVX C57BL/6 female mice as a model for postmenopausal osteoporosis. CSEs, acacetin, or linarin was orally administrated to OVX mice at a dose of 20 mg/kg for 8 weeks. Surgical estrogen loss in mice for 8 weeks reduced bone mineral density (BMD) of mouse femur and serum 17ß-estradiol level and enhanced the serum receptor activator of NF-κB ligand/osteoprotegerin ratio with uterine atrophy. CSEs and linarin reversed such adverse effects and enhanced femoral BMD in OVX mice. Oral administration of CSEs and linarin attenuated tartrate-resistant acid phosphate activity and the induction of αvß3 integrins and proton suppliers in resorption lacunae in femoral bone tissue of OVX mice. In addition, CSEs and linarin curtailed the bone levels of cathepsin K and matrix metalloproteinase-9 responsible for osteoclastic bone resorption. On the other hand, CSEs and linarin enhanced the formation of trabecular bones in estrogen-deficient femur with increased induction of osteocalcin and osteopontin. Further, treatment with CSEs and linarin enhanced the collagen formation-responsive propeptide levels in the circulation along with the increase in the tissue non-specific alkaline phosphatase level in bone exposed to OVX. Supplementing CSEs, acacetin, or linarin to OVX mice elevated the formation of collagen fibers in OVX trabecular bone, evidenced using Picrosirius red staining. Accordingly, CSEs and linarin were effective in retarding osteoclastic bone resorption and promoting osteoblastic bone matrix mineralization under OVX conditions. Therefore, linarin, which is abundant in CSEs, may be a natural compound for targeting postmenopausal osteoporosis and pathological osteoresorptive disorders.


Asunto(s)
Resorción Ósea , Cirsium , Osteoporosis Posmenopáusica , Animales , Femenino , Ratones , Densidad Ósea , Resorción Ósea/tratamiento farmacológico , Resorción Ósea/etiología , Colágeno/farmacología , Estrógenos/farmacología , Ratones Endogámicos C57BL , Osteoporosis Posmenopáusica/tratamiento farmacológico , Ovariectomía/efectos adversos
12.
Glia ; 70(3): 414-429, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34773273

RESUMEN

Oligodendrocytes are the cells that myelinate axons and provide trophic support to neurons in the CNS. Their dysfunction has been associated with a group of disorders known as demyelinating diseases, such as multiple sclerosis. Oligodendrocytes are derived from oligodendrocyte precursor cells, which differentiate into premyelinating oligodendrocytes and eventually mature oligodendrocytes. The development and function of oligodendrocytes are tightly regulated by a variety of molecules, including laminin, a major protein of the extracellular matrix. Accumulating evidence suggests that laminin actively regulates every aspect of oligodendrocyte biology, including survival, migration, proliferation, differentiation, and myelination. How can laminin exert such diverse functions in oligodendrocytes? It is speculated that the distinct laminin isoforms, laminin receptors, and/or key signaling molecules expressed in oligodendrocytes at different developmental stages are the reasons. Understanding molecular targets and signaling pathways unique to each aspect of oligodendrocyte biology will enable more accurate manipulation of oligodendrocyte development and function, which may have implications in the therapies of demyelinating diseases. Here in this review, we first introduce oligodendrocyte biology, followed by the expression of laminin and laminin receptors in oligodendrocytes and other CNS cells. Next, the functions of laminin in oligodendrocyte biology, including survival, migration, proliferation, differentiation, and myelination, are discussed in detail. Last, key questions and challenges in the field are discussed. By providing a comprehensive review on laminin's roles in OL lineage cells, we hope to stimulate novel hypotheses and encourage new research in the field.


Asunto(s)
Vaina de Mielina , Células Precursoras de Oligodendrocitos , Diferenciación Celular/fisiología , Laminina/metabolismo , Vaina de Mielina/metabolismo , Neurogénesis , Oligodendroglía/metabolismo
13.
Anal Chem ; 94(11): 4729-4736, 2022 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-35255211

RESUMEN

Indium tin oxide (ITO) is a popular electrode choice, with diverse applications in (photo)electrocatalysis, organic photovoltaics, spectroelectrochemistry and sensing, and as a support for cell biology studies. Although ITO surfaces exhibit heterogeneous local electrical conductivity, little is known as to how this translates to electrochemistry at the same scale. This work investigates nanoscale electrochemistry at ITO electrodes using high-resolution scanning electrochemical cell microscopy (SECCM). The nominally fast outer-sphere one-electron oxidation of 1,1'-ferrocenedimethanol (FcDM) is used as an electron transfer (ET) kinetic marker to reveal the charge transfer properties of the ITO/electrolyte interface. SECCM measures spatially resolved linear sweep voltammetry at an array of points across the ITO surface, with the topography measured synchronously. Presentation of SECCM data as current maps as a function of potential reveals that, while the entire surface of ITO is electroactive, the ET activity is highly spatially heterogeneous. Kinetic parameters (standard rate constant, k0, and transfer coefficient, α) for FcDM0/+ are assigned from 7200 measurements at sites across the ITO surface using finite element method modeling. Differences of 3 orders of magnitude in k0 are revealed, and the average k0 is about 20 times larger than that measured at the macroscale. This is attributed to macroscale ET being largely limited by lateral conductivity of the ITO electrode under electrochemical operation, rather than ET kinetics at the ITO/electrolyte interface, as measured by SECCM. This study further demonstrates the considerable power of SECCM for direct nanoscale characterization of electrochemical processes at complex electrode surfaces.


Asunto(s)
Compuestos de Estaño , Electroquímica , Electrodos , Oxidación-Reducción , Compuestos de Estaño/química
14.
Nat Mater ; 20(7): 1000-1006, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33737727

RESUMEN

Understanding how the bulk structure of a material affects catalysis on its surface is critical to the development of actionable catalyst design principles. Bulk defects have been shown to affect electrocatalytic materials that are important for energy conversion systems, but the structural origins of these effects have not been fully elucidated. Here we use a combination of high-resolution scanning electrochemical cell microscopy and electron backscatter diffraction to visualize the potential-dependent electrocatalytic carbon dioxide [Formula: see text] electroreduction and hydrogen [Formula: see text] evolution activity on Au electrodes and probe the effects of bulk defects. Comparing colocated activity maps and videos to the underlying microstructure and lattice deformation supports a model in which CO2 electroreduction is selectively enhanced by surface-terminating dislocations, which can accumulate at grain boundaries and slip bands. Our results suggest that the deliberate introduction of dislocations into materials is a promising strategy for improving catalytic properties.

15.
J Pathol ; 253(1): 55-67, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32918742

RESUMEN

Nonalcoholic fatty liver disease is a chronic condition involving steatosis, steatohepatitis and fibrosis, and its progression remains unclear. Although the tetraspanin transmembrane 4 L six family member 5 (TM4SF5) is involved in hepatic fibrosis and cancer, its role in nonalcoholic steatohepatitis (NASH) progression is unknown. We investigated the contribution of TM4SF5 to liver pathology using transgenic and KO mice, diet- or drug-treated mice, in vitro primary cells, and in human tissue. TM4SF5-overexpressing mice exhibited nonalcoholic steatosis and NASH in an age-dependent manner. Initially, TM4SF5-positive hepatocytes and liver tissue exhibited lipid accumulation, decreased Sirtuin 1 (SIRT1), increased sterol regulatory-element binding proteins (SREBPs) and inactive STAT3 via suppressor of cytokine signaling (SOCS)1/3 upregulation. In older mice, TM4SF5 promoted inflammatory factor induction, SIRT1 expression and STAT3 activity, but did not change SOCS or SREBP levels, leading to active STAT3-mediated ECM production for NASH progression. A TM4SF5-associated increase in chemokines promoted SIRT1 expression and progression to NASH with fibrosis. Suppression of the chemokine CCL20 reduced immune cell infiltration and ECM production. Liver tissue from high-fat diet- or CCl4 -treated mice and human patients exhibited TM4SF5-dependent steatotic or steatohepatitic livers with links between TM4SF5-mediated SIRT1 modulation and SREBP or SOCS/STAT3 signaling axes. TM4SF5-mediated STAT3 activation in fibrotic NASH livers increased collagen I and laminin γ2. Both collagen I α1 and laminin γ2 suppression resulted in reduced SIRT1 and active STAT3, but no change in SREBP1 or SOCS, and abolished CCl4 -mediated mouse liver damage. TM4SF5-mediated signaling pathways that involve SIRT1, SREBPs and SOCS/STAT3 promoted progression to NASH. Therefore, TM4SF5 and its downstream effectors may be promising therapeutic targets to treat nonalcoholic fatty liver disease. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/enzimología , Matriz Extracelular/enzimología , Metabolismo de los Lípidos , Cirrosis Hepática Experimental/enzimología , Hígado/enzimología , Proteínas de la Membrana/metabolismo , Enfermedad del Hígado Graso no Alcohólico/enzimología , Sirtuina 1/metabolismo , Animales , Tetracloruro de Carbono , Línea Celular Tumoral , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Enfermedad Hepática Inducida por Sustancias y Drogas/genética , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Dieta Alta en Grasa , Progresión de la Enfermedad , Matriz Extracelular/patología , Humanos , Hígado/patología , Cirrosis Hepática Experimental/inducido químicamente , Cirrosis Hepática Experimental/genética , Cirrosis Hepática Experimental/patología , Proteínas de la Membrana/genética , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Enfermedad del Hígado Graso no Alcohólico/inducido químicamente , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/patología , Transducción de Señal
16.
J Pediatr Nurs ; 65: e93-e98, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35422366

RESUMEN

PURPOSE: Depressive symptoms among adolescents are a major concern for increased risk of adverse health condition outcomes later in life. Specifically, previous studies have reported that multicultural adolescents experience more depressive symptoms than non-multicultural ones. Using the Korean Children and Youth Panel Survey, this study examined the relationships between ego-resilience, social support, and depression among multicultural adolescents in South Korea, as well as the moderating effect of social support on the association between ego-resilience and depression. DESIGN AND METHODS: A total of 1500 multicultural adolescents were included in the analyses, where generalized estimating equation models were employed. RESULTS: Depression scores increased slightly from 2012 to 2015. Higher levels of ego-resilience, family support, and friend support were associated with lower levels of depression, while teacher support was not a significant predictor. The moderating effect of friends and family support on the association between ego-resilience and depression was not statistically significant. CONCLUSIONS: To reduce the level of depression among multicultural adolescents, future research should develop interventions that enhance ego-resilience ability, as well as necessary social systems that strengthen family and friend support. PRACTICE IMPLICATIONS: Supportive interventions, such as enhancing ego-resilience to reduce depression should be provided to multicultural adolescents. It is recommended to include family and friends to develop effective intervention programs for multicultural adolescents who are suffering from depression.


Asunto(s)
Amigos , Apoyo Social , Adolescente , Niño , Ego , Humanos , República de Corea , Encuestas y Cuestionarios
17.
Int J Mol Sci ; 23(15)2022 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-35897732

RESUMEN

Interleukin-27 is constitutively secreted by microglia in the retina or brain, and upregulation of IL-27 during neuroinflammation suppresses encephalomyelitis and autoimmune uveitis. However, while IL-35 is structurally and functionally similar to IL-27, the intrinsic roles of IL-35 in CNS tissues are unknown. Thus, we generated IL-35/YFP-knock-in reporter mice (p35-KI) and demonstrated that photoreceptor neurons constitutively secrete IL-35, which might protect the retina from persistent low-grade inflammation that can impair photoreceptor functions. Furthermore, the p35-KI mouse, which is hemizygous at the il12a locus, develops more severe uveitis because of reduced IL-35 expression. Interestingly, onset and exacerbation of uveitis in p35-KI mice caused by extravasation of proinflammatory Th1/Th17 lymphocytes into the retina were preceded by a dramatic decrease of IL-35, attributable to massive death of photoreceptor cells. Thus, while inflammation-induced death of photoreceptors and loss of protective effects of IL-35 exacerbated uveitis, our data also suggest that constitutive production of IL-35 in the retina might have housekeeping functions that promote sterilization immunity in the neuroretina and maintain ocular immune privilege.


Asunto(s)
Enfermedades Autoinmunes , Interleucinas , Uveítis , Animales , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Privilegio Inmunológico , Inflamación/metabolismo , Interleucina-27/metabolismo , Interleucinas/genética , Interleucinas/metabolismo , Ratones , Ratones Endogámicos C57BL , Células Fotorreceptoras/metabolismo , Retina/metabolismo , Células Th17 , Uveítis/metabolismo
18.
J Nurs Manag ; 30(7): 2811-2824, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35593655

RESUMEN

AIMS: This study aimed to estimate the overall presenteeism prevalence in the nursing workforce. BACKGROUND: Nurses are more prone to presenteeism, which is associated with adverse outcomes for both nurses and patients. However, comprehensive information on the global prevalence of presenteeism in nursing workforce is lacking. EVALUATION: Seven databases were systematically searched without year or language restrictions in July 2021. Studies that reported the prevalence rate of presenteeism among nurses were included. A meta-analysis was performed using a random-effects model. KEY ISSUES: A total of 28 studies from 14 countries were included. The overall pooled estimate of presenteeism prevalence among nursing workforce was 49.2% (95% CI: 0.411, 0.574). Subgroup analyses showed that the prevalence of presenteeism was higher when the reporting time frame was >1 month and <1 year compared with ≤1 month or ≥1 year. CONCLUSION: The results of this meta-analysis showed the substantial prevalence of presenteeism in the nursing workforce with variations across different reporting time frames. IMPLICATION FOR NURSING MANAGEMENT: The findings can be used to support nurse managers, administrators and policymakers in recognizing the prevalence of presenteeism and developing relevant prevention strategies against presenteeism among global nursing workforce.


Asunto(s)
Personal de Enfermería , Presentismo , Humanos , Prevalencia , Recursos Humanos
19.
Medicina (Kaunas) ; 58(9)2022 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-36143949

RESUMEN

BACKGROUND AND OBJECTIVES: Bacterial antibiotics have had several side effects. Therefore, interest in natural substances with less side effects is increasing these days. Paeonia lactiflora, the root of Paeonia lactiflora, is used as a raw material for medicines. In this study, we investigated the antibacterial effect and the cytotoxicity of Paeonia lactiflora extract. MATERIALS AND METHODS: For cytotoxicity, MTT analysis according to ISO 10993-5 was performed. The antibacterial test of the Paeonia lactiflora was determined from bacterial viability, Inhibition zone test, CFU (colony forming unit) and SEM (scanning electron microscope). To confirm the antibacterial component of Paeonia lactiflora, the content of flavonoids and polyphenols was analyzed. RESULTS: Our results showed that Paeonia lactiflora extract contained flavonoids and polyphenols, which exhibited antimicrobial activity against Streptococcus mutans (S. mutans) and Candida albicans (C. ablicans). Further, the cytotoxicity of Paeonia lactiflora extract was low. CONCLUSIONS: We believe that our study makes a significant contribution to the literature because it demonstrates that Paeonia lactiflora extract can be used as an antibiotic.


Asunto(s)
Antiinfecciosos , Antineoplásicos , Paeonia , Antibacterianos/farmacología , Humanos , Metanol , Extractos Vegetales/farmacología , Polifenoles
20.
Medicina (Kaunas) ; 58(11)2022 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-36363513

RESUMEN

Background and Objectives The antimicrobial efficacy of a nonthermal atmospheric-pressure plasma jet (NAPPJ) on dental impression materials was investigated. Materials and Methods Type 3 polyvinyl siloxane was used as the impression material, and air and nitrogen NAPPJ were applied. The antibacterial effect of the NAPPJ was measured using the number of colony-forming units (CFUs) and scanning electron microscopy (SEM) images of Streptococcus mutans. Surface chemical characteristics of the impression material were examined using X-ray photoelectron spectroscopy (XPS) and contact angle measurement. Additionally, physical properties were analyzed through surface roughness measurement, detail reproduction, and strain-in-compression test. Results Compared with the control group, the plasma treatment group showed ruptured bacteria membranes, destroyed bacteria structures, a significant reduction in the number of CFUs, and a significantly reduced contact angle. Further, XPS analysis showed that their surface was significantly richer in hydroxyl groups. The surface roughness, detail reproduction, and strain-in-compression results indicated no significant differences between the plasma treatment and control groups. NAPPJ treatment could remove bacteria from polyvinyl siloxane dental impression materials without changing the surface's physical properties. Conclusion Therefore, it is considered a promising method for disinfection.


Asunto(s)
Gases em Plasma , Humanos , Gases em Plasma/farmacología , Gases em Plasma/química , Propiedades de Superficie , Ensayo de Materiales , Materiales de Impresión Dental
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