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To clarify the key role of oxygen vacancy defects on enhancing the oxidative activity of the catalysts, metal-organic frameworks (MOFs) derived MnOX catalysts with different morphologies and oxygen vacancy defects were successfully prepared using a facile in-situ self-assembly strategy with different alkali moderators. The obtained morphologies included three-dimensional (3D) triangular cone stacked MnOX hollow sphere (MnOX-H) and 3D nanoparticle stacked MnOX nanosphere (MnOX-N). Compared to MnOX-N, MnOX-H exhibited higher activity for the oxidation of toluene (T90 = 226 °C). This was mainly due to the large number of oxygen vacancy defects and Mn4+ species in the MnOX-H catalyst. In addition, the hollow structure of MnOX-H not only facilitated toluene adsorption and activation of toluene and also provided more active sites for toluene oxidation. Reaction mechanism studies showed that the conversion of toluene to benzoate could be realized over MnOX-H catalyst during toluene adsorption at room temperature. In addition, abundant oxygen vacancy defects can accelerate the activated oxidation of toluene and the formation of oxidation products during toluene oxidation.
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Mn(II)-oxidizing bacteria (MOB) are widely distributed in natural environments and can convert soluble Mn(II) into insoluble Mn(III) and Mn(IV). The biogenic manganese oxides (BioMnOx) produced by MOB have been considered for remediating heavy metal pollution and degrading organic pollutants in an eco-friendly manner. In this study, a manganese-oxidizing bacterium was isolated from Mn-polluted rivulet sediment and identified as Bacillus sp. strain M2 by PCR, phylogenetic tree construction, transmission electron microscopy (TEM), and physiological and biochemical indices. Strain M2 grew well under Mn(II) stress. BioMnOx with nanosized irregular geometric shapes and loose structures generated by strain M2 were found on the surface of the bacterial cells. The content of Mn in the bacteria was as high as 5.36%. Approximately 71.24% and 47.52% of Mn(II) was oxidized to Mn(III/IV) in the cell and in the deposits, respectively, within 3 d of cultivation with Mn(II). Extracellular enzymes contributed to the Mn removal and oxidation. In conclusion, Bacillus sp. strain M2 has a high potential for use in the remediation of Mn-contaminated sites.
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Herein we studied visible-light-driven CO2 reduction using a series of tetra-phenylporphyrin iron catalysts and inexpensive anthraquinone dyes. Varying the functional groups on the phenyl moieties of the catalysts significantly enhances the photocatalytic activity, achieving an optimal turnover number (TON) of 10 476 and a selectivity of 100% in the noble-metal-free systems. The highest activity found in a bromo-substituted catalyst is attributed to favorable electron transfer from the photosensitizer to the iron porphyrin.
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Herein, a novel chitosan Schiff base (CS-FGA) as a sustainable corrosion inhibitor has been successfully synthesized via a simple amidation reaction by using an imidazolium zwitterion and chitosan (CS). The corrosion inhibition property of CS-FGA for mild steel (MS) in a 1.0â¯M HCl solution was studied by various electrochemical tests and physical characterization methods. The findings indicate that the maximum inhibition efficiency of CS-FGA as a mixed-type inhibitor for MS in 1.0â¯M HCl solution with 400â¯mgâ¯L-1 reaches 97.6â¯%, much much higher than the CS and the recently reported chitosan-based inhibitors. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and water contact angle (WCA) results reveal that the CS-FGA molecules firmly adsorb on the MS surface to form a protective layer. The adsorption of CS-FGA on the MS surface belongs to the Langmuir adsorption isotherm containing both the physisorption and chemisorption. According to the X-ray photoelectron spectroscopy (XPS) and UV-vis spectrum, FeN bonds presented on the MS surface further prove the chemisorption between CS-FGA and Fe to generate the stable protective layer. Additionally, theoretical calculations from quantum chemical calculation (DFT) and molecular simulations (MD) were performed to reveal the inhibition mechanism of CS-FGA.
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Quitosano , Ácido Clorhídrico , Acero , Quitosano/química , Acero/química , Corrosión , Ácido Clorhídrico/química , Adsorción , Bases de Schiff/química , Soluciones , Espectroscopía de Fotoelectrones , Propiedades de SuperficieRESUMEN
Photocatalytic oxidation has gained great interest in environmental remediation, but it is still limited by its low efficiency and catalytic deactivation in the degradation of aromatic VOCs. In this study, we concurrently regulated the surface hydroxyl and oxygen vacancies by introducing Al into ZnSn layered double hydroxide (LDH). The presence of distorted Al species induced local charge redistribution, leading to the remarkable formation of oxygen vacancies. These oxygen vacancies subsequently increased the amount of surface hydroxyl and elongated its bond length. The synergistic effects of surface hydroxyl and oxygen vacancies greatly enhanced reactant adsorption-activation and facilitated charge transfer to generate â¢OH, â¢O2-, and 1O2, resulting in highly efficient oxidation and ring-opening of various aromatic VOCs. Compared with commercial TiO2, the optimized ZnSnAl-50 catalyst exhibited about 2-fold activity for the toluene and styrene degradation and 10-fold activity for the chlorobenzene degradation. Moreover, ZnSnAl-50 demonstrated exceptional stability in the photocatalytic oxidation of toluene under a wide humidity range of 0-75%. This work marvelously improves the photocatalytic efficiency, stability, and adaptability through a novel strategy of surface hydroxyl and oxygen vacancies engineering.
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Radical Hidroxilo , Oxígeno , Adsorción , Oxidación-Reducción , ToluenoRESUMEN
Purpose@#This study aimed to assess exposure to traumatic events, knowledge and attitudes concerning post-traumatic stress disorder (PTSD) and the level of resilience among nurses and paramedics working in emergency departments. @*Methods@#Data were collected from May 22 to June 12, 2022, using a self-administered survey questionnaire. The participants comprised 135 nurses and 80 paramedics working in emergency departments. The collected data were analyzed with descriptive statistics, a t-test, and an analysis of variance with Scheffé’s test. @*Results@#Compared with emergency room nurses, paramedics were more positive about the government’s spending on job opportunities for people with PTSD. There were no significant differences in attitude regarding government strategies and people with PTSD between nurses and paramedics. Paramedics had higher scores on the effective treatment for PTSD, while emergency room nurses showed higher scores on effective psychotherapy. General knowledge of PTSD differed according to sex (t=-2.33, p=.021) and education level (F=3.21, p=.042). Resilience scores differed significantly according to sex (t=2.02, p=.045), education level (F=4.10, p=.018), self-reported economic state (F=10.34, p<.001), and self-reported health (F=11.57, p<.001). @*Conclusion@#The findings support that emergency department nurses and paramedics are in need of self-care programs to support their mental health and indicate that intervention programs should be developed to enhance resilience in emergency department professionals.
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The present study assessed the residue levels of six parent neonicotinoids (p-NEOs) and four metabolites (m-NEOs) in indoor dust collected from 12 cities of China. Acetamiprid (ACE) and imidacloprid (IMI) were the predominated p-NEOs (detection rates: 98%) with the median values at 4.54 and 7.48 ng/g dry weight (dw), respectively. N-demethyl-acetamiprid (N-dm-ACE) was the most important m-NEO with the median value at 0.69 ng/g dw, while other m-NEOs were rarely detected (detection rates: < 15%). Significant correlation between ACE and thiacloprid (THD) was observed (p < 0.01), indicating their probably concurrent applications. ACE was significantly correlated to N-dm-ACE (p < 0.01), implicating the degradation of ACE in indoor environment. The estimated daily intake (EDIing) of NEOs via dust ingestion were far lower than the acceptable daily intake for NEOs. To our knowledge, this study provided a baseline nationwide investigation on the occurrence of NEOs in indoor dust of China.
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Contaminación del Aire Interior , Insecticidas , Humanos , Polvo/análisis , Insecticidas/análisis , Neonicotinoides/análisis , Encuestas y Cuestionarios , Nivel sin Efectos Adversos Observados , China , Contaminación del Aire Interior/análisisRESUMEN
Although amorphous materials are popular in oxygen electrocatalysis, their performance requires further improvement to meet the need for rechargeable zinc-air batteries. In this work, an amorphous/crystalline layered manganese oxide (ACMO) was designed, and its unique amorphous/crystalline homogeneous structure activated its oxygen reduction activity with a positive half-wave potential of 0.81â V and oxygen evolution activity with a moderate overpotential of 407â mV at 10â mA cm-2 . Moreover, the amorphous/crystalline structure endowed ACMO with excellent stability. While employed as the air-electrode material for rechargeable zinc-air batteries, ACMO overcame the poor cycling stability of manganese oxide and cycled stably for 1000â cycles (≈17â days) at 10â mA cm-2 . Besides, it delivered a high power density of 159.7â mW cm-2 and a narrow voltage gap of 0.66â V. This work gives an insight into designing oxide materials with amorphous/crystalline structure and feasible guidance for harmonizing electrochemical activity and stability.
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The catalysts for low-temperature selective catalytic reduction of NO with NH3 (NH3 -SCR) are highly desired due to the large demand in industrial furnaces. The characteristic of low-temperature requires the catalyst with rich active sites especially the redox sites. Herein, the authors obtain oxygen defect-rich ß-MnO2 from a crystal phase transformation process during air calcination, by which the as-prepared γ-MnO2 nanosheet and nanorod can be conformally transformed into the corresponding ß-MnO2 . Simultaneously, this transformation accompanies oxygen defects modulation resulted from lattice rearrangement. The most active ß-MnO2 nanosheet with plentiful oxygen defects shows a high efficiency of > 90% NO conversion in an extremely wide operation window of ≈120-350 °C. The detailed characterizations and density functional theory (DFT) calculations reveal that the introduction of oxygen defects enhances the adsorption properties for reactants and decreases the energy barriers of *NH2 formation more than 0.3 eV (≈0.32-0.37 eV), which contributes to a high efficiency of low-temperature SCR activity. The authors finding provides a feasible approach to achieve the oxygen defect engineering and gains insight into manganese-based catalysts for low-temperature NO removal or pre-oxidation.
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Compuestos de Manganeso , Oxígeno , Amoníaco , Catálisis , Oxidación-Reducción , ÓxidosRESUMEN
Purpose@#The number of Korean adolescents engaging in gambling is increasing, especially among out-of-school adolescents. This study aimed to identify patterns of gambling activities and factors related to specific subgroups of out-of-school adolescent gambling activities. @*Methods@#This descriptive study analyzed secondary data from the 2015 Korea Youth Gambling Problem Survey, including 1,200 out-of-school adolescents. Latent class analysis was conducted to identify patterns of gambling activities. The factors related to gambling subgroups were verified with multinomial logistic regression. @*Results@#Three latent classes of gambling activities were identified: rarely gambling (RG), immediate gain gambling (IGG), and broad gambling (BG). These subgroups differed significantly in terms of gender, age at and type of first gambling experience, number and type of gambling activities, gambling frequency, time and money spent on gambling, problem gambling severity, and motivation for gambling. Compared to the RG subgroup, both the IGG and BG subgroups were strongly associated with an older age at the first gambling experience. @*Conclusion@#Out-of-school adolescents who first gambled at an older age and who gambled mainly in order to gain money immediately were at risk of problem gambling. Developing strategies for early screening and referral to professionals is necessary to prevent gambling problems from worsening.
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Purpose@#The Life Transition Scale (LTS) consists of 24 items that assess the life transition process of parents of autistic children. This study aimed to examine the validity and reliability of the LTS in parents of children with a wide spectrum of disabilities. @*Methods@#Data were collected from 260 parents of children with disabilities through self-report questionnaires. Validity was examined using exploratory and confirmative factor analysis to determine the factor structures of the LTS; socio-demographic differences in LTS scores were examined using the t-test or ANOVA. Reliability was examined using Cronbach's ⍺ coefficient. @*Results@#A four-factor structure was validated (x2=640.0, p<.001, GFI=.81, RMSEA=.07, NNFI=.89, CFI=.89, PNFI=.74, Q [x2/df]=2.60). The validity of the LTS was verified by exploratory factor analysis, with factor loading ranging from .30 to .80. There were significant differences in the accepting phase according to children's and parents' age and the type of disability, and in the wandering phase according to parental gender, educational level, job, and socioeconomic status. The Cronbach's ⍺s for the reliability of each of the four structures were acceptable, within a range of .80~.90. @*Conclusion@#The LTS is a valid and reliable measurement to assess the life transition process of parents with disabled children.
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Purpose@#This study aimed to identify attitude and knowledge level on post-traumatic stress disorder (PTSD) among nursing and paramedic students. @*Methods@#A questionnaire survey was conducted from December 1st to 20th in 2019. A total of 210 students participated from two universities in Korea. Data were analyzed using descriptive statistics, t-tests and one-way analysis of variance. @*Results@#Students were positive about the government's spending on PTSD treatment (91.4%), and professional training (92.4%). PTSD patients were considered to be more dangerous (68.1%) and violent (42.4%) than the general population. There were no significant differences in attitude and general knowledge on PTSD between nursing and paramedic students. However, general knowledge on PTSD differed according to education experience on PTSD (t=2.04, p=.043). Knowledge scores for PTSD treatment differed significantly according to the academic major (t=2.02, p=.044), and education experience on PTSD (t=2.87, p=.005). @*Conclusions@#The results of this study indicate nursing and paramedic students lack knowledge on PTSD. Therefore, developing curriculum regarding PTSD-related contents in undergraduate and continuing education in both departments is needed to provide better quality health care to people with PTSD.
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Purpose@#This study aimed to identify attitude and knowledge level on post-traumatic stress disorder (PTSD) among nursing and paramedic students. @*Methods@#A questionnaire survey was conducted from December 1st to 20th in 2019. A total of 210 students participated from two universities in Korea. Data were analyzed using descriptive statistics, t-tests and one-way analysis of variance. @*Results@#Students were positive about the government's spending on PTSD treatment (91.4%), and professional training (92.4%). PTSD patients were considered to be more dangerous (68.1%) and violent (42.4%) than the general population. There were no significant differences in attitude and general knowledge on PTSD between nursing and paramedic students. However, general knowledge on PTSD differed according to education experience on PTSD (t=2.04, p=.043). Knowledge scores for PTSD treatment differed significantly according to the academic major (t=2.02, p=.044), and education experience on PTSD (t=2.87, p=.005). @*Conclusions@#The results of this study indicate nursing and paramedic students lack knowledge on PTSD. Therefore, developing curriculum regarding PTSD-related contents in undergraduate and continuing education in both departments is needed to provide better quality health care to people with PTSD.
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Developing a highly active and cost-effective cathode electrocatalyst with strong stability for oxygen reduction reaction (ORR) is extremely necessary. In this work, we reported a facile synthetic path to prepare a hybrid nanostructure formed of nitrogen-doped Ketjenblack carbon (N-KC) supported Co3O4 nanoparticles (Co3O4/N-KC), which could be used as a promising and stable electrocatalyst for ORR. Compared with the physical mixture of Co3O4 and N-KC and pure N-KC samples, the resulting Co3O4/N-KC nanohybrid afforded remarkably superb ORR activity with a half-wave potential of 0.82 V (vs. reversible hydrogen electrode, RHE) and a limiting current density of 5.70 mA cm-2 in KOH solution (0.1 M). Surprisingly, the Co3O4/N-KC sample possessed a similar electrocatalytic activity but better durability to the 20 wt% Pt/C catalyst. The remarkable ORR activity of the Co3O4/N-KC nanohybrid was mainly due to the strong coupling effect between Co3O4 and N-KC, the N species dopant, high electroconductivity, and the large BET surface area. Our work enlightens the exploitation of advanced Co3O4/carbon hybrid material alternative to the Pt-based electrocatalysts.
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Developing economic, effective and stable bifunctional electrocatalysts to achieve sustainable hydrogen production is highly desired. Herein, C-coated CoP hollow microporous nanocages (C-CoP-1/12) are synthesized by calcination of a Prussian blue analog precursor and subsequent phosphorization treatment. Under alkaline condition, the C-CoP-1/12 exhibit splendid electrocatalytic performance with a low overpotential of 173 mV for hydrogen evolution reaction (HER) and 333 mV for oxygen evolution reaction (OER) at a current density of 10 mA cm-2. The C-CoP-1/12 show high electrocatalytic performance for overall water splitting at a low potential of only 1.650 V for the driving current density of 10 mA cm-2, and they exhibit remarkable stability for at least 24 h. The engineering of phosphating is the critical step for the synthesis of pure-phase CoP with hollow nanoarchitecture. Compared with Co2P, CoP possesses lower water dissociation barrier and favorable ΔGH* value according to theoretical calculations, resulting in superior electrocatalytic performance. Such impressive water splitting performance is mainly attributed to the collective effects of metal phosphide with unique electronic structure, the shortened electron transport paths, and the conductive C coating. This strategy is believed to provide a basis for the development of electrode materials with highly efficient electrocatalytic water-splitting capability.
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PURPOSE: The purpose of this study was to identify the attributes, antecedents, and consequences of the transition of simulation-based learning (SBL) in nursing schools.METHODS: The study was conducted in accordance with Walker and Avant's conceptual analysis process. We searched MEDLINE, CINAHL, EMBASE, Google Scholar, and RISS (Korean Education and Research Information Service) databases, resulting in nine studies for an in-depth review.RESULTS: The attributes of transition of SBL include (1) preparing for a professional role, (2) practicing in a real clinical setting, and (3) progressing toward expected competency. Antecedents of the concept include novice status, changing roles, clinical experience in controlled settings, and expected competency in the clinical setting.CONCLUSION: The transition of SBL includes the important feature of progression toward expected competency. Further research is needed to identify graduate nurses' experiences during this transition to establish a strategy for improving it and developing a measurement tool that reflects attributes of the concept.
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Educación , Aprendizaje , Enfermería , Rol Profesional , Facultades de Enfermería , AndadoresRESUMEN
We present a facile method for the fabrication of hematite nanocrystal-carbon cloth (Fe2O3-CC) composite. Hierarchical manganite is chosen as the sacrificial precursor, that does not contribute to the component of final iron oxide but can be in situ dissolved by the acid produced from the Fe3+ hydrolysis. This method effectively enhances the specific surface area and conductivity of hematite (Fe2O3) by attaching Fe2O3 nanocrystals (around 5 nm) firmly on the surface of carbon fibers. The obtained Fe2O3-CC can be directly used as a binder-free electrode for a supercapacitor. Interestingly, the composite electrode exhibits synergistic electrochemical capacitance (electrochemical double-layer capacitance and pseudo-capacitance). It manifests a very high areal capacitance of 1.66 F cm-2 (1660 F g-1) at 2 mA cm-2 and excellent cycling performance at large current densities (88.6% retention at 30 mA cm-2 after 5000 cycles) in a three-electrode testing system, which is among the best performances reported in the literature. Importantly, when fabricated as a solid-state flexible symmetric supercapacitor it still shows a maximum energy density of 8.74 mW h cm-3 and power density of 253.9 mW cm-3. Additionally, its good flexibility makes it suitable for portable devices.
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PURPOSE: The purpose of this study was to evaluate the psychometric quality and feasibility of measurements for screening dysphagia in older adults to identify the 'right tool' for nurses to use in nursing homes. METHODS: A systematic review was done. Electronic databases were searched for studies related to dysphagia screening measurements. A checklist was used to evaluate the psychometric quality and applicability. Tools were evaluated for feasible incorporation into routine care by nurses. RESULTS: 29 tools from 31 studies were identified. Dysphagia screening tools with an acceptable validity and reliability had sensitivity between 68% and 100% and specificity between 52% and 100%. The Gugging Swallowing Screen (GUSS) and the Standardized Swallowing Assessment (SSA) were the tools with high psychometric quality, especially with high sensitivity, that nurses could perform feasibly to identify the risk and to grade the severity of dysphagia and aspiration of nursing home residents. CONCLUSION: Results show that GUSS and SSA are reliable and sensitive tools for screening dysphagia which nurses can use in nursing homes. Further research is needed to examine feasibility of screening with identified tools, and also, to establish effective and standardized protocols for these tools so they can be effectively incorporated into routine care.
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Humanos , Bases de Datos Factuales , Deglución , Trastornos de Deglución/diagnóstico , Casas de Salud , Sensibilidad y EspecificidadRESUMEN
In this work, we report the preparation of a free-standing membrane with strong mechanical stability and flexibility through a facile vacuum filtration approach. A field-emission scanning electron microscopy image demonstrates that the membrane composed of MnO2 nanowires is 50 nm in width and up to 100 µm long and the nanowires are assembled in parallel into bundles. A possible formation mechanism for the ultralong nanowires and the free-standing membrane has been proposed. Meanwhile, the properties of the membrane could be controlled by incorporating different materials to achieve composite membranes. In order to demonstrate the broad applicability of the MnO2 membrane, we fabricate a variety of composite membranes exhibiting various novel properties including magnetism and reversibly switchable wettability between hydrophilicity and hydrophobicity through various material modification, including CoFe2O4 nanoparticles and organic triethoxy(octyl)silane. Furthermore, the free-standing membrane could also simultaneously be functionalized with two materials, which reveal multiple properties. The synthesis method of a free-standing MnO2 membrane is simple and environmentally friendly, and it is easily scalable for industry. These composite membranes constitute a significant contribution to advanced technology.
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Compuestos de Manganeso/química , Nanocables/química , Óxidos/química , Técnicas Biosensibles , Catálisis , Interacciones Hidrofóbicas e Hidrofílicas , Sustancias Macromoleculares/química , Magnetismo , Ensayo de Materiales , Membranas Artificiales , Microscopía Electrónica de Transmisión/métodos , Nanopartículas/química , Nanotecnología/métodos , Oxígeno/química , Propiedades de Superficie , Temperatura , Agua/química , Humectabilidad , Difracción de Rayos XRESUMEN
PURPOSE: This study aimed to describe Korean nursing home nurses' perceptions on dysphagia management and their working experiences of older adults with dysphagia. METHODS: Using a purposive sampling design, 23 eligible nurses were interviewed as four focus groups from 4 facilities out of nursing homes. The qualitative data from focus group interviews were analyzed using thematic analysis to classify common themes into larger categories. RESULTS: Two main themes on the attributes of caring nursing home residents with dysphagia were 'Need for nursing resources' and 'Need for support'. In addition, four subthemes emerged as a result of analysis: 'need for nursing protocols for assessing and managing dysphagia', 'need for emergency care skills of nurses and nurse assistants', 'need for prompt and accurate management by cooperation of physicians and therapists', and 'need for partnership upon comprehension of visiting family members concerning dysphagia'. CONCLUSION: Nursing home nurses fully recognized the importance of dysphagia management; however, they experienced substantial barriers due to lack of adequate nursing protocols or partnership with family caregivers, insufficient training for emergency care, and deficient support from medical staff. Development of nursing guidelines tailored to the nursing home context and based on partnership among medical experts and family caregivers is needed.