Over the past decade, the catalytic activity of nanozymes has been greatly enhanced, but their selectivity is still low and considered a critical issue to overcome. Herein, Fe–N4 single site embedded ...graphene (Fe–N‐rGO), which resembles the heme cofactor present in natural horseradish peroxidase, shows a marked enhancement in peroxidase‐like catalytic efficiency of up to ≈700‐fold higher than that of undoped rGO as well as excellent selectivity toward target H2O2 without any oxidizing activity. Importantly, when Fe or N is doped alone or when Fe is replaced with another transition metal in the Fe–N4 site, the activity is negligibly enhanced, showing that mimicking the essential cofactor structure of natural enzyme might be essential to design the catalytic features of nanozymes. Density functional theory results for the change in Gibbs free energy during the peroxide decomposition reaction explain the high catalytic activity of Fe–N‐rGO. Based on the high and selective peroxidase‐like activity of Fe–N‐rGO, trace amounts of H2O2 produced from the enzymatic reactions from acetylcholine and cancerous cells are successfully quantified with high sensitivity and selectivity. This work is expected to encourage studies on the rational design of nanozymes pursuing the active site structure of natural enzymes.
Fe–N4 single‐site embedded graphene (Fe–N‐rGO) resembling the heme cofactor present in natural horseradish peroxidase shows a significant enhancement in peroxidase‐like activity without any oxidizing activity. These results demonstrate that mimicking the essential cofactor structure of natural enzyme might be a vital element to design the catalytic features of nanozymes, not limited to horseradish peroxidase alone.
Several studies have reported negative relations between allergic diseases and school performance but have not simultaneously considered various allergic diseases, including allergic rhinitis, ...asthma, and atopic dermatitis, and only examined a limited number of participants. The present study investigated the associations of allergic rhinitis, asthma, and atopic dermatitis with school performance in a large, representative Korean adolescent population. A total of 299,695 7th through 12th grade students participated in the Korea Youth Risk Behaviour Web-based Survey (KYRBWS) from 2009 to 2013. The subjects' history of allergic rhinitis, asthma, and atopic dermatitis and number of school absences due to these diseases in the previous 12 months were examined and compared. School performance was classified into 5 levels. The relations between allergic disorders and school performance were analyzed using multiple logistic regressions with complex sampling and adjusted for the subjects' durations of sleep, days of physical activity, body mass indexes (BMIs), regions of residence, economic levels, parents' education levels, stress levels, smoking status, and alcohol use. A subgroup analysis of the economic groups was performed. Allergic rhinitis was positively correlated with better school performance in a dose-dependent manner (adjusted odds ratios, AOR, 95% confidence interval, CI = 1.50 1.43-1.56 > 1.33 1.28-1.38 > 1.17 1.13-1.22 > 1.09 1.05-1.14 for grades A > B > C > D; P < 0.001). Asthma was negatively correlated with better school performance (AOR 95% CI = 0.74 0.66-0.83, 0.87 0.79-0.96, 0.83 0.75-0.91, 0.93 0.85-1.02 for performance A, B, C, and D, respectively; P < 0.001). Atopic dermatitis was not significantly correlated with school performance. The subgroup analysis of the students' economic levels revealed associations between allergic diseases and school performance. Compared to other allergic disorders, the asthma group had more school absences due to their symptoms (P < 0.001). School performance was positively correlated with allergic rhinitis and negatively correlated with asthma in Korean adolescents, even after adjusting for other variables. The asthma group had an increased number of school absence days, which presumably contributes to these students' poor school performance.
IMPORTANCE: Among young adults, the association of the 2017 American College of Cardiology/American Heart Association (ACC/AHA) High Blood Pressure Clinical Practice Guidelines with risk of ...cardiovascular disease (CVD) later in life is uncertain. OBJECTIVE: To determine the association of blood pressure categories before age 40 years with risk of CVD later in life. DESIGN, SETTING, AND PARTICIPANTS: This population-based cohort study from the Korean National Health Insurance Service consisted of 2 488 101 adults aged 20 through 39 years with blood pressure measurements taken twice from 2002 through 2005. Starting from January 1, 2006, participants were followed up until the date of CVD diagnosis, death, or December 31, 2015. EXPOSURES: Participants were categorized by blood pressure readings: normal (systolic, <120 mm Hg; diastolic, <80 mm Hg), elevated (sytolic, 120-129 mm Hg; diastolic, <80 mm Hg), stage 1 hypertension (systolic, 130-139 mm Hg; diastolic, 80-89 mm Hg), and stage 2 hypertension (systolic, ≥140 mm Hg; diastolic, ≥90 mm Hg). MAIN OUTCOMES AND MEASURES: The primary outcome was CVD defined as 2 or more days of hospitalization due to CVD or death due to CVD. The secondary outcomes were coronary heart disease (CHD) and stroke. RESULTS: The study population consisted of 2 488 101 participants (median age, 31 years interquartile range, 27-36 years, 789 870 women 31.7%). A total of 44 813 CVD events were observed during a median follow-up duration of 10 years. Men with baseline stage 1 hypertension compared with those with normal blood pressure had higher risk of CVD (incidence, 215 vs 164 per 100 000 person-years; difference, 51 per 100 000 person-years 95% CI, 48-55; adjusted hazard ratio HR, 1.25 95% CI, 1.21-1.28), CHD (incidence, 134 vs 103 per 100 000 person-years; difference, 31 per 100 000 person-years 95% CI, 28-33; adjusted HR, 1.23 95% CI, 1.19-1.27), and stroke (incidence, 90 vs 67 per 100 000 person-years; difference, 23 per 100 000 person-years 95% CI, 21-26; adjusted HR, 1.30 95% CI, 1.25-1.36). Women with baseline stage 1 hypertension compared with those with normal blood pressure had increased risk of CVD (incidence, 131 vs 91 per 100 000 person-years; difference, 40 per 100 000 person-years 95% CI, 35-45; adjusted HR, 1.27 95% CI, 1.21-1.34), CHD (incidence, 56 vs 42 per 100 000 person-years; difference, 14 per 100 000 person-years 95% CI, 11-18; adjusted HR, 1.16 95% CI, 1.08-1.25), and stroke (incidence, 79 vs 51 per 100 000 person-years; difference, 28 per 100 000 person-years 95% CI, 24-32; adjusted HR 1.37, 95% CI, 1.29-1.46). Results for state 2 hypertension were consistent. CONCLUSIONS AND RELEVANCE: Among Korean young adults, stage 1 and stage 2 hypertension, compared with normal blood pressure, were associated with increased risk of subsequent cardiovascular disease events. Young adults with hypertension, defined by the 2017 ACC/AHA criteria, may be at increased risk of cardiovascular disease.
Sodium‐ion hybrid supercapacitors (Na‐HSCs) have potential for mid‐ to large‐scale energy storage applications because of their high energy/power densities, long cycle life, and the low cost of ...sodium. However, one of the obstacles to developing Na‐HSCs is the imbalance of kinetics from different charge storage mechanisms between the sluggish faradaic anode and the rapid non‐faradaic capacitive cathode. Thus, to develop high‐power Na‐HSC anode materials, this paper presents the facile synthesis of nanocomposites comprising Nb2O5@Carbon core–shell nanoparticles (Nb2O5@C NPs) and reduced graphene oxide (rGO), and an analysis of their electrochemical performance with respect to various weight ratios of Nb2O5@C NPs to rGO (e.g., Nb2O5@C, Nb2O5@C/rGO‐70, ‐50, and ‐30). In a Na half‐cell configuration, the Nb2O5@C/rGO‐50 shows highly reversible capacity of ≈285 mA h g−1 at 0.025 A g−1 in the potential range of 0.01–3.0 V (vs Na/Na+). In addition, the Na‐HSC using the Nb2O5@C/rGO‐50 anode and activated carbon (MSP‐20) cathode delivers high energy/power densities (≈76 W h kg−1 and ≈20 800 W kg−1) with a stable cycle life in the potential range of 1.0–4.3 V. The energy and power densities of the Na‐HSC developed in this study are higher than those of similar Li‐ and Na‐HSCs previously reported.
Nb2O5@Carbon core–shell nanoparticles and reduced graphene oxide nanocomposites (Nb2O5@C/rGO) for new energy storage systems, namely sodium‐ion hybrid supercapacitors (Na‐HSCs), are presented. A Na‐HSC system comprising an Nb2O5@C/rGO anode and an MSP‐20 cathode delivers high energy and power densities (≈76 W h kg−1 and ≈20 800 W kg−1), with excellent cycling stability.
The purpose of this study was to examine the difference between self-reported hearing status and hearing impairment assessed using conventional audiometry. The associated factors were examined when a ...concordance between self-reported hearing and audiometric measures was lacking.
In total, 19,642 individuals ≥20 years of age who participated in the Korea National Health and Nutrition Examination Surveys conducted from 2009 through 2012 were enrolled. Pure-tone hearing threshold audiometry (PTA) was measured and classified into three levels: <25 dB (normal hearing); ≥25 dB <40 dB (mild hearing impairment); and ≥40 dB (moderate-to-severe hearing impairment). The self-reported hearing loss was categorized into 3 categories. The participants were categorized into three groups: the concordance (matched between self-reported hearing loss and audiometric PTA), overestimation (higher self-reported hearing loss compared to audiometric PTA), and underestimation groups (lower self-reported hearing loss compared to audiometric PTA). The associations of age, sex, education level, stress level, anxiety/depression, tympanic membrane (TM) status, hearing aid use, and tinnitus with the discrepancy between the hearing self-reported hearing loss and audiometric pure tone threshold results were analyzed using multinomial logistic regression analysis with complex sampling.
Overall, 80.1%, 7.1%, and 12.8% of the participants were assigned to the concordance, overestimation, and underestimation groups, respectively. Older age (adjusted odds ratios AORs = 1.28 95% confidence interval = 1.19-1.37 and 2.80 2.62-2.99 for the overestimation and the underestimation groups, respectively), abnormal TM (2.17 1.46-3.23 and 1.59 1.17-2.15), and tinnitus (2.44 2.10-2.83 and 1.61 1.38-1.87) were positively correlated with both the overestimation and underestimation groups. Compared with specialized workers, service workers, manual workers, and the unemployed were more likely to be in the overestimation group (1.48 1.11-1.98, 1.39 1.04-1.86, and 1.50 1.18-1.90, respectively), and service workers were more likely to be in the underestimation group (AOR = 1.42 1.01-1.99). Higher education level (0.77 0.59-1.01 and 0.43 0.33-0.57) and hearing aid use (0.36 0.17-0.77 and 0.23 0.13-0.43) were negatively associated with being in the underestimation group (0.43 0.37-0.50). Compared with males, females were less likely to be assigned to the underestimation group (0.43 0.37-0.50). Stress (1.98 1.32-2.98) and anxiety/depression (1.30 1.06-1.59) were associated with overestimation group.
Older age, lower education level, occupation, abnormal TM, non-hearing aid use, and tinnitus were related to both overestimation and underestimation groups. Male gender was related to underestimation, and stress and anxiety/depression were correlated with overestimation group. An understanding of these factors associated with the self-reported hearing loss will be instrumental to identifying and managing hearing-impaired individuals.
The objective of this study was to compare the incidence of post-operative depression in breast cancer patients who have undergone mastectomy with the incidence of post-operative depression in ...non-breast cancer participants (controls).
Using data from the Korean Health Insurance Review and Assessment Service (HIRA), we selected 2,130 patients with breast cancer who have undergone mastectomy for this national cohort study and matched these patients 1:4 with 8,520 control participants according to age, sex, income, region, and pre-operative depression. The incidence of post-operative depression was measured from mastectomy year to post-op year 10. The Mann-Whitney U test was used for data analysis, and the false-discovery rate was applied to determine statistical significance (P < 0.05).
The incidence of depression was higher in the breast cancer with mastectomy group than in the control group up to 3 years after mastectomy). However, there was no difference in the incidence of depression between the breast cancer with mastectomy group and the control group after post-op 4 years. The incidence of depression was higher in the breast cancer with mastectomy group than in the control group up to 2 years after mastectomy, and there was no difference in the incidence of depression between the two groups after post-op 3 years in middle-aged and older adults (≥ 40 years old). In young adults (≤ 39 years old), the incidence of depression was significantly higher in the breast cancer with mastectomy group than in the control group in mastectomy year.
Patients undergoing mastectomy for breast cancer experience depression more frequently than healthy people. However, patients overcome their depressive mood symptoms during the postoperative period. Young adults overcome their symptoms more quickly than middle-aged and older adults.
Although overuse of the internet has been suggested to be related to poor academic performance, the effects of internet use for education on academic performance showed conflict results in previous ...studies. Accordingly, the associations of school performance with internet use for study and for general purpose were explored in a large population of Korean adolescents. Cross-sectional data from the 2013 Korean Youth Risk Behaviour Web-based Survey (KYRBWS) were retrieved for 59,105 12- to 18-year-old adolescents. The associations between school performance and internet use were analysed using multinomial logistic regression with complex sampling. Days of physical activity, sex, obesity, region of residence, income level, parental education level, stress, sleep time, smoking, alcohol consumption, drug use, and total study time were recorded and adjusted for as confounders. Higher school performance was positively associated with longer internet use for study (adjusted odds ratio, AOR, of 2+ h 95% confidence interval = 2.43 2.10-2.82, 2.02 1.78-2.30, 1.66 1.46-1.89, and 1.30 1.15-1.47 for performance groups A, B, C, and D, respectively, P < 0.001) but negatively associated with longer internet use for general purpose (AOR of 3+ h 95% confidence interval = 0.68 0.60-0.78, 0.85 0.76-0.94, 0.83 0.75-0.92, and 0.98 0.89-1.08 for performance groups A, B, C, and D, respectively, P < 0.001). Higher school performance significantly positively correlated with internet use for study but negatively correlated with internet use for general purpose. Academic use of the internet could be a means of achieving good school performance.
Current antisense oligonucleotide (ASO) therapies for the treatment of central nervous system (CNS) disorders are performed through invasive administration, thereby placing a major burden on ...patients. To alleviate this burden, we herein report systemic ASO delivery to the brain by crossing the blood–brain barrier using glycemic control as an external trigger. Glucose‐coated polymeric nanocarriers, which can be bound by glucose transporter‐1 expressed on the brain capillary endothelial cells, are designed for stable encapsulation of ASOs, with a particle size of about 45 nm and an adequate glucose‐ligand density. The optimized nanocarrier efficiently accumulates in the brain tissue 1 h after intravenous administration and exhibits significant knockdown of a target long non‐coding RNA in various brain regions, including the cerebral cortex and hippocampus. These results demonstrate that the glucose‐modified polymeric nanocarriers enable noninvasive ASO administration to the brain for the treatment of CNS disorders.
The sweet spot: Antisense‐oligonucleotide‐loaded glucosylated‐polyion‐complex micelles can be used for RNA knockdown in various brain regions using blood‐glucose level as an external trigger. Glucose transporter‐1 expressed on the brain capillary endothelial cells binds the glucose‐coated nanocarrier and transports it, along with its cargo, across the blood–brain barrier. This could be used for the treatment of disorders of the central nervous system.
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