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Controlled oxidation of palladium nanoparticles provided high-valent PdIV oxo-clusters which efficiently promote directed C-H halogenation reactions. In addition, palladium nanoparticles can undergo changes in oxidation states to provide both high-valent PdIV and low-valent Pd0 species within one system, and thus a tandem reaction of C-H halogenation and cross-coupling (C-N, C-C, and C-S bond formation) was successfully established.
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This paper reviews recent developments in the field of hybrid Pd nanoparticles and their catalytic activity in the Suzuki coupling reaction, which is used extensively in the fabrication of both simple and complex biaryl compounds. We developed three types of Pd-silica hybrid nanoparticles. Pd/SiO2 nanobeads containing tiny Pd clusters, Pd@nickel phyllosilicate yolk-shell nanoparticles, Pd@porous SiO2 yolk-shell nanoparticles were synthesized, and they displayed highly efficient catalytic activity and excellent reusability. The hybrid nanoparticles also catalyzed the Suzuki coupling reaction with various substrates, including bromobenzene and chlorobenzene. This review also briefly discusses the synthesis procedure, structural characterization, and catalytic activity of hybrid Pd nanoparticles.
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Ácidos Borónicos/química , Halógenos/química , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Paladio/química , Catálisis , Tamaño de la PartículaRESUMEN
Particulate matter (PM) and volatile organic compounds (VOCs) are recognised as hazardous air pollutants threatening human health. Disposable filters are generally used for air purification despite frequent replacement and waste generation problems. However, the development of a novel regenerable and robust filter for long-term use is a huge challenge. Here, we report on a new class of facile water-washing regenerable ceramic catalyst filters (CCFs), developed to simultaneously remove PM (>95%) and VOCs (>82%) in single-pass and maximized space efficiency by coating the inner and outer filter channels with an inorganic membrane and a Cu2O/TiO2 photocatalyst, respectively. The CCFs reveal four-fold increase in the maximum dust loading capacity (approximately 20 g/L) in relation to conventional filters (5 g/L), and can be reused after ten regeneration capability with simple water washing retaining initial PM and VOC removal performances. Thus, the CCFs can be well-suited for indoor and outdoor air purification for 20 years, which shows a huge increase in lifetime compared to the 6-month lifespan of conventional filters. Finally, we believe that the development and implementation of CCFs for air purification can open new avenues for sustainable technology through renewability and zero-waste generation.
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The surface of Pd@SiO(2) core-shell nanoparticles (1) was simply modified by the formation of nickel phyllosilicate. The addition of nickel salts formed branched nickel phyllosilicates and generated pores in the silica shells, yielding Pd@SiO(2)-Niphy nanoparticles (Niphy = nickel phyllosilicate; 2, 3). By removal of the silica residue, Pd@Niphy yolk-shell nanoparticles (4) was uniformly obtained. The four distinct nanostructures (1-4) were employed as catalysts for Suzuki coupling reactions with aryl bromide and phenylboronic acid, and the conversion yields were in the order of 1 < 2 < 3 < 4 as the pore volume and surface area of the catalysts increased. The reaction rates were strongly correlated with shell porosity and surface exposure of the metal cores. The chemical inertness of nickel phyllosilicate under the basic conditions rendered the catalysts reusable for more than five times without loss of activity.
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PURPOSE: This study investigated the changes in the health-related behaviors of adult women in Korea during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: Data from the eighth Korea National Health and Nutrition Examination Survey (2019- 2020) were analyzed. The participants were 4,848 women aged 19 to 64 years in 2019 and 2020. Data analysis using the complex sampling design was performed using SPSS 20.1. RESULTS: Positive changes during the pandemic compared to before the pandemic in Korean adult women were found for improved subjective oral health perceptions (odds ratio [OR], 1.77; p<.001), increased moderate-intensity exercise in work and leisure activities (OR, 1.75; p<.001 and OR; 1.29, p=.004), and a decrease in secondhand smoke exposure at the workplace and in public places (OR, 0.64; p=.004 and OR, 0.60; p<.001). However, the following negative health behavior changes were found: decreased frequency of walking 5 days a week (OR, 0.81; p=.011) and an increase in unhealthy daytime sleep durations (OR, 1.40; p=006). CONCLUSION: Compared to before the COVID-19 pandemic, Korean adult women perceived their subjective dental health more positively during the COVID-19 pandemic, decreased their exposure to secondhand smoke at work and in public places, decreased walking, and increased sleep duration during the week. Since this study only compared data between 1 year before and after the start of the pandemic, it is necessary to investigate a longer period of time in the future. A future study should attempt to identify the factors related to changes in health behaviors caused by the pandemic.
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Purpose: This study examined health behaviors, use of health services, and depression among women who perform daytime and shift work in Korea, as well as factors related to depression. Methods: We conducted a secondary analysis using data from the 2018 data of the 7th Korea National Health and Nutrition Examination Survey. Data on women, 1,493 regular daytime workers and 322 shift workers, were analyzed. Results: Women shift workers were younger (χ2=43.97, p<.001), had a lower education level (χ2=45.56, p<.001), and lower personal income (χ2=16.85, p=.030) than their daytime counterparts. A higher proportion of shift workers were unmarried (χ2=37.47, p<.001) and they typically worked fewer than 40 hours per week (χ2=69.94, p<.001). The depression score of shift workers was higher than that of daytime workers (t=2.85, p=.005). A higher proportion of shift workers also drank alcohol (χ2=6.49, p=.032) and smoked (χ2=30.79, p<.001). Over 8% of shift workers typically slept fewer than 5 hours per night (χ2=14.17, p=.024). It was confirmed that depression in women shift workers was affected by age, personal income, marital status, health status, and smoking status, in addition to cancer screening participation, unmet medical care needs, and unmet dental care needs. Conclusion: More attention should be given to the health needs of women working shifts. Health promotion programs specific for women shift workers are needed to improve their physical and mental health, encourage use of medical care services, and improve public health policies and systems.
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Purpose: This study investigated the impact of coronavirus disease 2019 (COVID-19) on women's health nursing clinical practicums in undergraduate nursing schools in Korea during the spring 2020 semester. Methods: A cross-sectional online survey on clinical practicum teaching experiences in the spring 2020 semester was distributed to members of the Korean Society of Women Health Nursing (KSWHN) who taught undergraduate nursing. One faculty member from each of 203 institutions was requested to respond and there were no duplicate participants. Seventy-nine participants (38.9%) responded and 74 responses were analyzed. Descriptive statistics were presented for all survey items. Results: Fifty-two faculty members (70.3%) belonged to universities and 22 (29.7%) taught at colleges. Thirty-eight (51.4%) answered that their institutions had affiliated teaching hospitals. More than half (52.7%) conducted hospital-based clinical practicums either entirely (n=20) or partially (n=19), whereas the rest of them (47.3%) conducted clinical practicums at school or home via online teaching. The typical teaching methods for offline or online education were case conferences, tests or quizzes, scenario studies, nursing skill practicums, (virtual) nursing simulations, and simulated patient education. Most of faculties (93.2%) supported the development of an educational platform to share educational materials and resources, such as case scenarios. Conclusion: Nursing faculty members utilized various teaching methods to enhance clinical skills and mitigate limited clinical exposure during the early stage of the COVID-19 pandemic. The KSWHN should move forward to develop an education platform and modalities for members who face many challenges related to the accessibility and quality of nursing education contents.
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An approach for gram-scale synthesis of uniform Cu2O nanocubes by a one-pot polyol process was used. The CuO hollow nanostructures were prepared by adding aqueous ammonia solutions with Cu2O nanocube colloidal solutions. CuO hollow nanospheres on acetylene black (CuO/AB), were synthesized and used for the catalytic [3+2] cycloaddition of azides with terminal alkynes to provide products in good yields with high regioselectivity. The CuO/AB was readily separated by centrifugation and could be reused ten times under the present reaction conditions without any loss of catalytic activity. Transition metals loaded onto acetylene black are useful reagents for a wide variety of organic transformations. Moreover, these heterogeneous systems are promising industrial catalysts.
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Purpose: This study was conducted to identify unmet healthcare needs among man and woman one-person households and to explore related factors by gender. Methods: Data were drawn from the 2017 Korea National Health and Nutrition Examination Survey. The final sample consisted of 820 one-person households. The statistical analysis, conducted in SPSS version 20.1, included complex sampling analysis; descriptive statistics, the chi-square test, and logistic regression. Results: The demographic and socioeconomic characteristics of women in one-person households were significantly different from those of men in one-person households. Women in single-person households were mainly in their 70s or older and married, and they tended to have a low education level, low income, and no formal occupation. Unmet healthcare needs were experienced by 17.3% of women in one-person households and 13.5% of men in one-person households, which was not a statistically significant difference (χ2=2.17, p=.139). Factors related to unmet healthcare needs were subjective health status and unmet dental care needs in single-person-household men. By contrast, having experienced impairment within the past year, stress, and unmet dental care needs were factors related to unmet healthcare needs in single-person-household women. Conclusion: As one-person households become increasingly common, more attention needs to be paid to them and our understanding of them needs to be improved. Women in one-person households, in particular, are especially vulnerable, as they experience more unmet healthcare needs.
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PURPOSE: This study was to identify health behavior, health service use, and health related quality of life of adult women in one-person and multi-person households. METHODS: It was used data from the 7th Korea National Health and Nutrition Examination Survey (KNHANES VII-2017). Subjects were 2,522 women with age of 19 to 64 years in 2017. Complex sampling design and data analysis were performed using SPSS 20.1. RESULTS: Women in one-person households had higher rates of alcohol drinking (χ²=13.77, p=.003), smoking (χ²=16.07, p=.001), unmet medical care (χ²=8.77, p=.004) and non-practice of cancer screening (χ²=13.77, p=.003) compared to women in multi-person households. Health-related quality of life was also lower for women in one-person households (t=-2.46, p=.015). Factors affecting health-related quality of life in one-person households were household income, job status, and unmet dental care, having 32.4% explanatory power. One-person household women with low incomes, no jobs, and unmet dental care showed low health-related quality of life. In comparison, factors affecting health-related quality of life of women in multi-person household women were age, education level, unmet medical care, and unmet dental care, having 10.4% explaining power. Women in multi-person households with age of 60-64, low education level, unmet medical care, and unmet dental care showed low health-related quality of life. CONCLUSION: Health promotion strategies should be developed based on unique understanding of social, economic, and health of adult women in one-person and multi-person households.
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PURPOSE: Maternal Fetal Intensive Care Unit (MFICU), which provides intensive care to high-risk mothers with increasing maternal age and high-risk newborns, has become a new field of nursing work in South Korea. The present study was conducted to identify the educational needs and self-assessing clinical competence of nurses in MFICU. METHODS: The education needs and competencies of MFICU nurses were measured through prepared questionnaires by researchers based on the previous studies on job analysis of nurses in MFICU. Data were collected from January 2019 to March 2019. The study involved 168 nurses working in MFICUs at 12 hospitals nationwide as study subjects. The data were analyzed using the SPSS WIN 23.0 program. RESULTS: The education needs of nurses in MFICU had an average of 4.21 points (±0.50) and their nursing competence was average 3.38 points (±0.60). The items reported as high education needs but low competency by nurses in MFICU were as following: 'postpartum hemorrhage and shock,' 'cardiopulmonary resuscitation (CPR) for neonate,' 'CPR during pregnancy,' 'disseminated intravascular coagulation,' 'sepsis,' and 'mechanical ventilation during pregnancy.' CONCLUSION: Based on these results, it is proposed that a comprehensive education program for nurses in MFICU should be developed by considering low capabilities among MFICU nurses as a priority factor.
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PURPOSE: To describe nursing students' experience of sexual harassment during clinical practicum. METHODS: An interpretive phenomenological qualitative approach was used to understand contextual experiences of participants. Individual in-depth interviews were conducted to collect data from thirteen nursing students who experienced sexual harassment during clinical practice in general hospitals at D metropolitan city. All interviews were recorded and transcribed into Korean and English. Transcripts were analyzed using the data analysis method described by Diekelmann, Allen, and Tanner. RESULTS: The following 12 themes emerged from the data: 'unprepared to respond', 'lack of education', 'unsure about when behavior crosses the line', 'power differential for nursing students', 'balancing self-preservation with obligations to patients', 'shame', 'feeling responsible for not being able to prevent the harassment', 'impact on patient care', 'fear of what might have happened', 'fear of repercussions', 'long term impact', and 'peer support'. CONCLUSION: Participants in this study described feeling an obligation to care for their patients. However, they seemed to be unable to balance this while feeling vulnerable to sexual harassment with strong negative feelings. Helping students recognize and effectively deal with sexual harassment is a critical element to assure quality learning for participants and maintain quality of care during clinical practice.
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Although numerous morphologies of MnO nanostructures have been reported, an exact structural analysis and mechanistic study has been lacking. In the present study, the formation of regular MnO octapods was demonstrated in a simple procedure, comprising the thermal decomposition of manganese oleate. Because of their structural uniformity, an ideal three-dimensional model was successfully constructed. The eight arms protruded from the cubic center with tip angles of 38° and surface facets of {311} and {533} with rounded edges. The concentrations of oleate and chloride ions were the determining factors for the octapod formation. Selective coordination of the oleate ions to the {100} faces led to edge growth along the <111> direction, which was then limited by the chloride ions bound to the high-index surface facets. These structural and mechanistic analyses should be helpful for understanding the complex nanostructures and for tuning their structure-related properties.
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PURPOSE: This study is to investigate the influencing factors in the consistent use of contraception methods by comparing consistent and inconsistent users on partner communication, contraceptive control perception, and sexual autonomy among married Korean women. METHOD: This study consists of 243 married women living in Korea. A convenient sampling technique was used and data were collected by self report questionnaires from September 14, 2000 to October 20, 2000. RESULT: Only 41.6% of women were using contraception methods consistently and the rest of them were using contraception methods inconsistently. Between the two groups, statistical significances were noted in sexual communication(t=-2.5, p=.01), perceived contraceptive control(t=-7.5, p=.00) and sexual autonomy(t=-3.1, p=.00). As for general communication, it was not statistically significant(t=-1.0, p=.31). CONCLUSION: Family planning program advisors should recognize that intervention programs for the promotion of consistent contraceptive behavior should focus on the sexual communication, perceived contraceptive control, and sexual autonomy.
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The Pd(iv) species, known to be critical intermediates in homogeneous catalysis, were successfully generated on the surface of Pd nanocatalysts via oxidation with iodobenzene dichloride (PhICl2) or N-chlorosuccinimide (NCS). In particular, the Pd@SiO2 yolk-shell nanocatalyst activated by PhICl2 showed high reactivity and superior stability to the other Pd-based catalysts for hydroalkoxylation reactions even at 25 °C.