Metal–organic frameworks (MOFs) are an attractive catalyst support for stable immobilization of the active sites in their scaffold due to the high tunability of organic ligands. The active ...site‐functionalized ligands can be easily employed to construct MOFs as porous heterogeneous catalysts. However, the existence of active sites on the external surfaces as well as internal pores of MOFs seriously impedes the selective reaction in the pore. Herein, through a simple post‐synthetic ligand exchange (PSE) method we synthesized surface‐deactivated (only core‐active) core–shell‐type MOF catalysts, which contain 2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl (TEMPO) groups on the ligand as active sites for aerobic oxidation of alcohols. The porous but catalytically inactive shell ensured the size‐selective permeability by sieving effects and induced all reactions to take place in the pores of the catalytically active core. Because PSE is a facile and universal approach, this can be rapidly applied to a variety of MOF‐based catalysts for enhancing reaction selectivity.
Site control: Removing catalytic sites near the surface of the MOF crystal allowed for enhanced size discrimination of the reactants thus improving selectivity.
Nuclear factor erythroid 2-related factor (Nrf2) is a transcriptional activator of the cell protection gene that binds to the antioxidant response element (ARE). Therefore, Nrf2 protects cells and ...tissues from oxidative stress. Normally, Kelch-like ECH-associated protein 1 (Keap1) inhibits the activation of Nrf2 by binding to Nrf2 and contributes to Nrf2 break down by ubiquitin proteasomes. In moderate oxidative stress, Keap1 is inhibited, allowing Nrf2 to be translocated to the nucleus, which acts as an antioxidant. However, under unusually severe oxidative stress, the Keap1-Nrf2 mechanism becomes disrupted and results in cell and tissue damage. Oxide-containing atmospheric environment generally contributes to the development of respiratory diseases, possibly leading to the failure of the Keap1-Nrf2 pathway. Until now, several studies have identified changes in Keap1-Nrf2 signaling in models of respiratory diseases, such as acute respiratory distress syndrome (ARDS)/acute lung injury (ALI), chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), and asthma. These studies have confirmed that several Nrf2 activators can alleviate symptoms of respiratory diseases. Thus, this review describes how the expression of Keap1-Nrf2 functions in different respiratory diseases and explains the protective effects of reversing this expression.
Emerging scientific evidence indicates that frequent digital technology use has a
significant impact-both negative and positive-on brain function and behavior. Potential
harmful effects of extensive ...screen time and technology use include heightened
attention-deficit symptoms, impaired emotional and social intelligence, technology
addiction, social isolation, impaired brain development, and disrupted sleep. However,
various apps, videogames, and other online tools may benefit brain health. Functional
imaging scans show that internet-naive older adults who learn to search online show
significant increases in brain neural activity during simulated internet searches.
Certain computer programs and videogames may improve memory, multitasking skills, fluid
intelligence, and other cognitive abilities. Some apps and digital tools offer mental
health interventions providing self-management, monitoring, skills training, and other
interventions that may improve mood and behavior. Additional research on the positive
and negative brain health effects of technology is needed to elucidate mechanisms and
underlying causal relationships.
The synthesis of amine skeletons and catalytic bond formation in aliphatic amines are important synthetic methodologies. Although various metal‐catalyzed organic transformations have been ...successfully used to functionalize and construct amine molecules, there are still many hurdles toward practical application. Moreover, site‐selectivity is generally achieved using a traditional directing group (DG) strategy, which requires at least two additional steps for the installation and removal of the DGs. Recently, a transient directing group (TDG) strategy, also known as traceless DG and temporary DG, has been widely studied for a range of selective transition metal‐catalyzed C─H bond functionalization. In this account, we have focused on the recent developments of the TDG strategy toward the site‐selective C─H bond functionalization of aliphatic amines. The design of the TDGs used for the target reaction and their critical roles in the reaction mechanism will be covered along with their selectivity and synthetic utility.
TDG‐assisted C─H functionalization of aliphatic amines.
This study was conducted to define the abdomen types of Korean elderly women and to develop an abdominal fat ratio (AFR) estimation equation using key body measurements and indexes that well ...represented the body type characteristics of elderly women. An analysis was performed of the correlations between the individual obesity-related measurements and index items to explain the body shape characteristics and obesity trends in elderly women. To derive the equation for estimating the AFR of elderly women, the abdominal types of elderly women were classified, and then, the distribution of each type was investigated. Then, a simple regression analysis was performed in which the dependent variable is predicted by using a single predictor. The AFR and WHtR (Waist-Height Ratio) showed a higher correlation with the obesity-related measurement items and indexes; thus, an equation was derived that enables the estimation of the AFR using simple body measurements. Additionally, the morphological differences of the various abdomen types were analyzed to provide the trends of the abdomen types depending on the AFR in the elderly. This new model for estimating abdominal fat percentage developed in the present study is significant in that it uses relatively easy-to-obtain anthropometric measures like height and waist circumference. The results of the present study demonstrated the relationship between WHtR, which not only well reflects elderly obesity but is also closely related to the prevalence of obesity in the elderly. This finding suggests that the shape of the abdomen will serve as a potential health indicator in the future.
In urban areas, a major source of harmful particulate matter is generated by vehicles. In particular, bus stops, where people often stay for public transportation, generate high concentrations of ...particulate matter compared to the general atmosphere. In this study, a non-powered type brush filter that generates electrostatic force without using a separate power source was developed to manage the concentration of particulate matter exposed at bus stops, and the removal performance of particulate matter was evaluated. The dust collection performance of the non-motorized brush filter varied by material, with particle removal efficiencies of 82.1 ± 3.4, 76.1 ± 4.7, and 73.7 ± 4.5% for horse hair, nylon, and stainless steel, respectively. In conditions without the fan running to see the effect of airflow, the particle removal efficiency was relatively low at 58.2 ± 8.4, 53.6 ± 9.2, and 58.0 ± 7.3%. Then, to check the dust collection performance according to the density, the number of brushes was increased to densify the density, and the horse hair, nylon, and stainless steel brush filters showed a maximum dust collection performance of 89.6 ± 2.2, 88.3 ± 3.2, and 82.1 ± 3.8%, respectively. To determine the replacement cycle of the non-powered brush filter, the particulate removal performance was initially 88.0 ± 3.2% when five horse hair brushes were used. Over time, particulate matter tended to gradually decrease, but after a period of time, particulate matter tended to increase again. The purpose of this study is to evaluate the particulate matter removal performance using a brush filter that generates electrostatic force without a separate power source. This study’s brush filter is expected to solve the maintenance problems caused by the purchase and frequent replacement of expensive HEPA filters that occur with existing abatement devices, and the ozone problems caused by abatement devices that use high voltages.
Aerosols carrying viruses that are released from the oral cavity of infected individuals are the primary, if not the only, means of transmission during viral respiratory disease epidemics. This makes ...crowded rooms and tiny, enclosed public areas like bathrooms prime environments for the transmission of diseases. Volatile organic compounds (VOCs) and formaldehyde are two contaminants that pose serious threats to human health and well-being in indoor environments. The varied disinfectant properties of chlorine dioxide (ClO2) make it a key player in treating a range of air quality issues. To balance effectiveness and safety, however, the careful application of chlorine dioxide is essential to achieving the best results in air quality while preserving human health and well-being. This study explores the many functions of chlorine dioxide, including the prevention of the spread of viruses, the elimination of harmful gases like ammonia and hydrogen sulfide, and its effects on formaldehyde and total volatile organic compounds (TVOCs) in indoor environments using BT100. The results indicate a reduction of 98.5%, 81.01%, 62.22%, 46.5%, and 63.84% in minimizing aerosolized viruses, ammonia, and hydrogen sulfide gas in addition to formaldehyde and total volatile organic compounds.
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Despite the worldwide effect of the coronavirus disease 2019 (COVID-19) pandemic, the underlying mechanisms of fatal viral pneumonia remain elusive. Here, we show that critical COVID-19 is associated ...with enhanced eosinophil-mediated inflammation when compared to non-critical cases. In addition, we confirm increased T helper (Th)2-biased adaptive immune responses, accompanying overt complement activation, in the critical group. Moreover, enhanced antibody responses and complement activation are associated with disease pathogenesis as evidenced by formation of immune complexes and membrane attack complexes in airways and vasculature of lung biopsies from six fatal cases, as well as by enhanced hallmark gene set signatures of Fcγ receptor (FcγR) signaling and complement activation in myeloid cells of respiratory specimens from critical COVID-19 patients. These results suggest that SARS-CoV-2 infection may drive specific innate immune responses, including eosinophil-mediated inflammation, and subsequent pulmonary pathogenesis via enhanced Th2-biased immune responses, which might be crucial drivers of critical disease in COVID-19 patients.
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•Critical COVID-19 is associated with enhanced eosinophil-mediated inflammation•FcγR signal and complement activation are elevated in critical COVID-19•Immune complexes and MAC are consistently detected in lung tissues from fatal cases•Th2-biased humoral responses are associated with critical COVID-19
Kim et al. find that critical COVID-19 is associated with enhanced eosinophil-mediated inflammation when compared to non-critical cases. Increased Th2-biased immune responses, accompanying overt complement activation, are seen in the critical group. These findings suggest that enhanced eosinophil-mediated inflammation and dysregulated humoral responses might be drivers of severe COVID-19.
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