New microporous organic-inorganic hybrid nickel phosphonate material has been synthesized via non-templated hydrothermal pathway, which can be pyrolyzed in air and nitrogen atmospheres to produce ...heteroatom-doped NP/NiO and NO/NiP materials with good electrocatalytic activities for oxygen evolution reaction.
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•Synthesis of NiPPA derived heteroatom doped material NP/NiO, NO/NiP by pyrolysis.•NP/NiO material exhibited excellent electrocatalytic behavior.•Overpotential and Tafel slope of NP/NiO are 332 mV and 65.6 mV dec−1.•NP/NiO reveals the excellent stability up to 15 h.
Designing low-cost and highly efficient electrocatalysts based on widely abundant elements is highly desirable for future green energy production. Transition metal oxides and phosphides have recently been demonstrated to be promising and cost-effective electrocatalysts due to their distinct surface properties and good conductivity. Herein, we have synthesized a new microporous organic-inorganic hybrid nickel phosphonate (NiPPA) material under hydrothermal reaction condition without the use of structure directing agent. The microporous NiPPA material can be converted to N, P-codoped nickel oxide (NP/NiO) and N, O-codoped nickel phosphide (NO/NiP) following pyrolysis under air and nitrogen atmospheres, respectively. These high surface area materials are subsequently explored as electrocatalysts towards oxygen evolution reaction (OER) in alkaline media. Among the three catalysts, NP/NiO exhibits the highest electrocatalytic activity for OER with an overpotential of 332 mV to reach a current density of 10 mA cm−2 and a low Tafel slope of 65.6 mV dec−1 in 1.0 M KOH solution. Furthermore, the as-prepared NP/NiO catalyst displays an outstanding stability over a period of 15 h, suggesting the high durability of this catalyst for OER.
A synthesis strategy for the preparation of ultrathin free‐standing ternary‐alloy nanosheets is reported. Ultrathin Pd‐Pt‐Ag nanosheets with a thickness of approximately 3 nm were successfully ...prepared by co‐reduction of the metal precursors in an appropriate molar ratio in the presence of CO. Both the presence of CO and the interplay between the constituent metals provide fine control over the anisotropic two‐dimensional growth of the ternary‐alloy nanostructure. The prepared Pd‐Pt‐Ag nanosheets were superior catalysts of ethanol electrooxidation owing to their specific structural and compositional characteristics. This approach will pave the way for the design of multicomponent 2D nanomaterials with unprecedented functions.
Ultrathin Pd‐Pt‐Ag nanosheets with a thickness of approximately 3 nm were successfully prepared by the co‐reduction of suitable metal precursors in an appropriate molar ratio in the presence of CO. These nanosheets are superior catalysts of ethanol electrooxidation owing to their specific structural and compositional characteristics.
Post-inflammatory hyperpigmentation is a skin discoloration process that occurs following an inflammatory response or wound. As the skin begins to heal, macrophages first exhibit a proinflammatory ...phenotype (M1) during the early stages of tissue repair and then transition to a pro-healing, anti-inflammatory phenotype (M2) in later stages. During this process, M1 macrophages remove invading bacteria and M2 macrophages remodel surrounding tissue; however, the relationship between macrophages and pigmentation is unclear. In this study, we examined the effect of macrophages on melanin pigmentation using human induced pluripotent stem cells. Functional melanocytes were differentiated from human induced pluripotent stem cells and named as hiMels. The generated hiMels were then individually cocultured with M1 and M2 macrophages. Melanin synthesis decreased in hiMels cocultured with M1 macrophages but significantly increased in hiMels cocultured with M2 macrophages. Moreover, the expression of vascular endothelial growth factor was increased in M2 cocultured media. Our findings suggest that M2 macrophages, and not M1 macrophages, induce hyperpigmentation in scarred areas of the skin during tissue repair.
Due to unique structural porosity, low‐cost, and good catalytic activity, oxygen evolution reactions over 3d transition elements have gained immense attention in recent years. Herein, we report the ...fabrication of three different metal phosphates, e. g. Co‐phosphate (CoPO), Ni‐phosphate (NiPO), and Ni−Co‐phosphate (NiCoPO) using the corresponding metal sources and phosphoric acid as a phosphorus source under hydrothermal conditions without using any structure‐directing agent. Since the as‐prepared metal‐based phosphates exhibit high surface area with good interparticle porosity and contain transition metals in the material frameworks, these materials have been investigated for electrocatalytic oxygen evolution reaction (OER). Among the three metal phosphates, the as‐synthesized CoPO catalyst shows efficient electrocatalytic activity toward OER, with an overpotential of 350 mV at 10 mA cm−2 in 1.0 M KOH solution and a relatively low Tafel slope of 60.7 mV dec−1. The good electrocatalytic performance of CoPO is attributed to its higher specific surface area and pore volume compared to other two catalysts. The CoPO‐modified electrode also shows a high stability up to 15 h at a constant potential of 1.58 V, suggesting its promising future for OER catalysis.
Porous metal phosphates for electrochemical water oxidation: Three different transition metal‐based phosphates have been synthesized under hydrothermal conditions which have been explored for electrochemical water oxidation reaction in alkaline KOH solution.
The development of telemonitoring via wireless body area networks (WBANs) is an evolving direction in personalized medicine and home-based mobile health. A WBAN consists of small, intelligent medical ...sensors which collect physiological parameters such as electrocardiogram, electroencephalography, and blood pressure. The recorded physiological signals are sent to a coordinator via wireless technologies, and are then transmitted to a healthcare monitoring center. One of the most widely used wireless technologies in WBANs is ZigBee because it is targeted at applications that require a low data rate and long battery life. However, ZigBee-based WBANs face severe interference problems in the presence of WiFi networks. This problem is caused by the fact that most ZigBee channels overlap with WiFi channels, severely affecting the ability of healthcare monitoring systems to guarantee reliable delivery of physiological signals. To solve this problem, we have developed an algorithm that controls the load in WiFi networks to guarantee the delay requirement for physiological signals, especially for emergency messages, in environments with coexistence of ZigBee-based WBAN and WiFi. Since WiFi applications generate traffic with different delay requirements, we focus only on WiFi traffic that does not have stringent timing requirements. In this paper, therefore, we propose an adaptive load control algorithm for ZigBee-based WBAN/WiFi coexistence environments, with the aim of guaranteeing that the delay experienced by ZigBee sensors does not exceed a maximally tolerable period of time. Simulation results show that our proposed algorithm guarantees the delay performance of ZigBee-based WBANs by mitigating the effects of WiFi interference in various scenarios.
Reliable nutrient load estimation of a reservoir is challenging due to inconsistent spatial extent and temporal frequency of water quality and quantity measurements. This study aims to collect ...consistent spatial extent and temporal frequency of water depths and nitrate concentrations of a reservoir in South Korea using uncrewed surface vehicle (USV). In this study, reservoir nitrate loads were estimated using four methods to examine how spatial variation in water depth and nitrate concentrations affected load estimates. Based on dual measurements of water depth and nitrate concentration, reservoir nitrate loads across 30 sampling dates (0.7 million tons of fresh water on average) ranged from one to four tons. Results showed that a point measurement of water depths and nitrate concentrations can cause up to −17% of underestimation of nitrate loads, particularly after intense rainfall events. This study highlights potential opportunities and challenges of the USV‐based dual monitoring systems for water quality and quantity.
Plain Language Summary
Water quantity and quality are monitored at different spatial extent and temporal frequency. This study used an uncrewed boat to measure the water depth and nitrate concentration of a reservoir in the mid‐eastern Korean Peninsula at considering the spatial component and temporal components. This uncrewed boat was equipped with water depth and nitrate concentration sensors. During the study period (2021–2022), uncrewed boats conducted 30 surveys. We found strong seasonal variations in nitrate load estimates in the reservoir, particularly during the wet season These results suggest that estimating nitrate loads from depth measurements at a point measurement in a reservoir can lead to underestimates. This study is a case study how the cutting‐edge technologies like our uncrewed boat equipped with environmental sensors can be used for the next‐generation water monitoring system.
Key Points
An uncrewed surface vehicle (USV) was used to map water depth and nitrate concentration at a 10‐m resolution
Nutrient load estimates varied up to 17% when comparing the USV method to a point‐measurement method
Limitations and challenges of USV‐based surveys for water quantity and quality were discussed
Large-scale integration of vanadium dioxide (VO2) on mechanically flexible substrates is critical to the realization of flexible smart window films that can respond to environmental temperatures to ...modulate light transmittance. Until now, the formation of highly crystalline and stoichiometric VO2 on flexible substrate has not been demonstrated due to the high-temperature condition for VO2 growth. Here, we demonstrate a VO2-based thermochromic film with unprecedented mechanical flexibility by employing graphene as a versatile platform for VO2. The graphene effectively functions as an atomically thin, flexible, yet robust support which enables the formation of stoichiometric VO2 crystals with temperature-driven phase transition characteristics. The graphene-supported VO2 was capable of being transferred to a plastic substrate, forming a new type of flexible thermochromic film. The flexible VO2 films were then integrated into the mock-up house, exhibiting its efficient operation to reduce the in-house temperature under infrared irradiation. These results provide important progress for the fabrication of flexible thermochromic films for energy-saving windows.
Recently, the world has witnessed increased participation from nondemocratic countries in international cultural institutions, such as UNESCO's International Assistance (IA) program. This study poses ...the question of why several authoritarian countries request IA programs more frequently than others do. In addition to economic and international factors, we argue that differences in domestic institutions within autocracies influence the decision-making of such states in requesting IA programs because these programs can be a useful tool for several incumbent regimes to generate public support or maintain their status. We implement negative binomial regressions for 131 authoritarian countries between 1979 and 2014 and demonstrate that politically competitive regimes are more likely to request IA programs than non-competitive ones. The findings suggest that authoritarian regimes with competitive political institutions are likely to utilize the programs of cultural international regimes.
Recientemente, el mundo ha observado una mayor participación de países no democráticos en instituciones culturales internacionales, tales como el programa de Asistencia Internacional (International Assistance, IA) de la UNESCO. Este estudio plantea la pregunta de por qué numerosos países autoritarios solicitan programas de IA con más frecuencia que otros países. Además de los factores internacionales y económicos, sostenemos que las diferencias en las instituciones nacionales dentro de las autocracias influyen en la toma de decisiones de tales estados al solicitar programas de IA, ya que estos programas pueden ser una herramienta útil para que los regímenes de turno obtengan el apoyo del público o mantengan su posición. Implementamos regresiones binomiales negativas para 131 países autoritarios entre 1979 y 2014, y demostramos que los regímenes políticamente competitivos son más propensos a solicitar programas de IA que los que no lo son. Los resultados sugieren que es probable que los regímenes autoritarios con instituciones políticas competitivas utilicen los programas de regímenes culturales internacionales.
Le monde a récemment été témoin d'une participation accrue des pays non démocratiques aux institutions culturelles internationales, notamment au niveau des programmes d'aide internationale de l'UNESCO. Cette étude s'interroge sur les raisons pour lesquelles plusieurs pays autoritaires demandent des programmes d'aide internationale plus fréquemment que d'autres. En plus des facteurs économiques et internationaux, nous soutenons que les différences dans les institutions nationales des autocraties influencent la prise de décision de ces États lorsqu'ils demandent des programmes d'aide internationale, car ces programmes peuvent être un outil utile pour plusieurs régimes en place pour générer un soutien public ou maintenir leur statut. Nous avons appliqué des régressions binomiales négatives pour 131 pays autoritaires entre 1979 et 2014 et nous démontrons que les régimes politiquement concurrents sont davantage susceptibles de demander des programmes d'aide internationale que les régimes non concurrents. Nos conclusions suggèrent que les régimes dont les institutions politiques sont concurrentes sont susceptibles d'avoir recours aux programmes des régimes culturels internationaux.
Dendritic Au−Pd alloy nanoparticles were synthesized in high yield through the coreduction of HAuCl4 and K2PdCl4 in aqueous solutions by using hydrazine as a reducing agent. Relative compositions ...between Au and Pd at the particle surfaces as well as in bulk phases could be modulated by controlling the molar ratios between metal precursors in the feeding solutions. The formation of nanodendrites may be the result of the fast reduction rate of metal ions and subsequent fast, kinetically controlled growth of particles. The prepared alloy nanoparticles exhibit efficient electrocatalytic activities and stabilities toward ethanol oxidation in alkaline media. The enhanced electrocatalytic properties of dendritic particles can be attributed to the presence of a large number of active sites on their surfaces.
Background/Objectives
Subcutaneous panniculitis‐like alpha‐beta T‐cell lymphoma is a rare disease, which comprises less than 1% of all non‐Hodgkin lymphoma. The epidemiology of this disorder has not ...been established in New Zealand, particularly the ethnic variation.
Methods
A retrospective study was conducted from 2005 to 2017 in South Auckland, New Zealand. Patients with histopathologically confirmed subcutaneous panniculitis‐like alpha‐beta T‐cell lymphoma, according to the WHO‐EORTC classification, were included. Cases were identified from multiple data sources to ensure the study population was completely surveyed. Census data were used as the denominator.
Results
Ten cases were identified. Five were men and five women. The median age at diagnosis was of 38.5 years (range 17–73 years). Nine were Māori/Pacific, and one was European. The ethnic relative risk of subcutaneous panniculitis‐like alpha‐beta T‐cell lymphoma in Māori/Pacific versus European was 11.1 (95% Cl 1.83–246.1, P = 0.005).
Conclusion
Māori and Pacific have a higher relative risk of subcutaneous panniculitis‐like alpha‐beta T‐cell lymphoma compared to non‐Māori/Pacific.
