Fused Functional Organic Material with the Alternating Conjugation of Quinone-Pyrazine as Cathode for Aqueous Zinc Ion Batteries.

Organic cathode materials for aqueous rechargeable zinc batteries (ARZBs) are rapidly gaining prominence, while the exploration of compounds with affordable synthesis, satisfactory electrochemical performance, and understandable mechanisms still remains challenging. In this study, 6,8,15,17-tetraaza-heptacene-5,7,9,14,16,18-hexaone (TAHQ) as an easily synthesized organic cathode material with novel quinone/pyrazine alternately conjugated molecule structure is presented. This organic electrode exhibits good capacity with highly reversible redox reactions, and the influence of multi-active structures on the Zn2+ /H+ loading behavior is systematically investigated by ex situ spectroscopy, electrochemical tests, and computation. Both experimental and theoretical studies effectively address the Zn2+ /H+ intercalation/deintercalation kinetics. Benefitting from the fused active functionalities, the assembled Zn//TAHQ battery displays a maximum discharge specific capacity of 254.3 mAh g-1 at 0.5 A g-1 , and it maintains remarkable cycle performance with 71% capacity retention after 1000 cycles under 5 A g-1 .

Engineering Low-Cost Organic Cathode for Aqueous Rechargeable Battery and Demonstrating the Proton Intercalation Mechanism for Pyrazine Energy Storage Unit.

Seeking organic cathode materials with low cost and long cycle life that can be employed for large-scale energy storage remains a significant challenge. This work has synthesized an organic compound, triphenazino[2,3-b](1,4,5,8,9,12-hexaazatriphenylene) (TPHATP), with as high as 87.16% yield. This compound has a highly π-conjugated and rigid molecular structure, which is synthesized by capping hexaketocyclohexane with three molecules of 2,3-diaminophenazine derived from low-cost o-phenylenediamine, and is used as a cathode material for assembling aqueous rechargeable zinc ion batteries. Both experiments and DFT calculations demonstrate that the redox mechanism of TPHATP is predominantly governed by H+ storage. The Zn-intercalation product of nitride-type compound, is too unstable to form in water. Moreover, the TPHATP cathode exhibits a capacity of as high as 318.3 mAh g-1 at 0.1 A g-1 , and maintained a stable capacity of 111.9 mAh g-1 at a large current density of 10 A g-1 for 5000 cycles with only a decay of 0.000512% per cycle. This study provides new insights into understanding pyrazine as an active redox group and offers a potential affordable aqueous battery system for grid-scale energy storage.

High capacity adsorption of antimony in biomass-based composite and its consequential utilization as battery anode.

Antimony is more than an emerging pollutant in water but a scare resource. In this study, we report an adsorbent with the record capacity so far from the balanced view of Sb(III) and Sb(V). The composite adsorbent was fabricated by encapsulating hollow Fe3O4 nanosphere with the EDTA grafted chitosan, and it has superhigh adsorption capacity of for 657.1 mg/g for Sb(III) and 467.3 mg/g for Sb(V), respectively. The mechanism study reveals that the adsorption of Sb initializes from the Fe3O4, propagates along the chitosan with hydrogen bond, and terminates at the inner sphere complex with the EDTA moiety in the adsorbent. In view of the ultra-high adsorption capacity of the adsorbent, the recovered adsorbent that contains abundant (>36.4%) highly dispersed antimony nanoparticles (600-FCSE-Sb) is applied to Li-ion battery anode after reduction. This article provides a new idea for connecting water treatment and electric energy storage.

Fe, Ni-modified ZIF-8 as a tensive precursor to derive N-doped carbon as Na and Li-ion batteries anodes.

Carbon materials derived from metal-organic frameworks have attracted increasing attention as anodes for energy storage. In this study, Fe, Ni-doped ZIF-8 is carbonized at high temperature to obtain bimetallic Fe and Ni modified tension -relaxed carbon (FeNi@trC). Fe and Ni have opposite structural modification effects when the metal ions are doped into the ZIF-8 dodecahedron. The obtained carbon material maintains the regular dodecahedron morphology, which means the relaxation of tension and strong thermal stability during annealing. Moreover, the presence of nickel enhances the carbonization degree and electrochemical stability of FeNi@trC, while the calcination of the tensive ZIF-8 precursor offers more defect sites. The discharge capacities of FeNi@trC materials are stable at 182.9 mAh·g-1and 567.9 mAh·g-1for sodium-ion batterie (SIB) and lithium-ion batterie (LIB) at 0.05 A·g-1. Compared with the current density of 0.05 A·g-1, the discharge capacity of SIB and LIB attenuates by 29.4% and 55.9% at 1 A·g-1, respectively, and the FeNi@trC shows good performance stability in the following cycles.

Organic Zinc-Ion Battery: Planar, π-Conjugated Quinone-Based Polymer Endows Ultrafast Ion Diffusion Kinetics.

A novel poly(phenazine-alt-pyromellitic anhydride) (PPPA) has been successfully designed and synthesized via a condensation polymerization strategy as promising cathode material in organic zinc-ion batteries. Electrochemical quartz crystal microbalance (EQCM), FTIR and XPS characterizations verify a reversible Zn2+ -coordination mechanism in our PPPA cathode. Intriguingly, an ultrahigh Zn2+ diffusion coefficient of 1.2×10-7  cm2 s-1 was found in this large π-conjugated system, which is the highest one among all organic cathode materials for zinc-ion batteries. Theoretical calculations reveal the extended π-conjugated plane in our PPPA sample results in a significant reduction on energy gap, effectively accelerating intramolecular electron transfer during charge/discharge process. Our finding provides insights to achieve high zinc-ion transport kinetics by a design strategy on planar polymer system.

Engineering monodispersed 2 nm Sb2S3 particles embedded in a porphyrin-based MOF-derived mesoporous carbon network via an adsorption method to construct a high-performance sodium-ion battery anode.

Sodium ion batteries (SIBs) are expected to replace lithium ion batteries (LIBs) as the next generation of large-scale energy storage applications because of their superior cost performance. However, the larger ionic radius of Na+ causes a remarkable volume expansion than that of Li+ during charge and discharge, which reduces the performance of the battery. In this work, we engineered a composite material in that monodispersed 2 nm Sb2S3 particles are uniformly loaded into a carbon matrix (Sb2S3/CZM), which is obtained by carbonization of a zirconium-based MOF with adsorption of Sb. The obtained composite material has a high specific surface area in favor of mass transfer, and the porous structure can resist many volume changes in the circulation process. Moreover, the ultrafine Sb2S3 particles are well-distributed in the composite material, which increases the utilization of the active substance and is promising for the storage of Na+. Based on its unique structure, the Sb2S3/CZM composite shows a specific capacity of 550 mA h g-1 at 100 mA g-1 and an excellent cycling stability of 88.9% retention after 1000 cycles at 3 A g-1. The excellent electrochemical performance provides enlightenment for the rational design of hierarchical heterostructures for energy storage applications.

Time-variant reproductive number of COVID-19 in Seoul, Korea / 한국역학회지

OBJECTIVES@#To estimate time-variant reproductive number (Rt) of coronavirus disease 19 based on either number of daily confirmed cases or their onset date to monitor effectiveness of quarantine policies. @*METHODS@#Using number of daily confirmed cases from January 23, 2020 to March 22, 2020 and their symptom onset date from the official website of the Seoul Metropolitan Government and the district office, we calculated Rt using program R’s package “EpiEstim”. For asymptomatic cases, their symptom onset date was considered as -2, -1, 0, +1, and +2 days of confirmed date. @*RESULTS@#Based on the information of 313 confirmed cases, the epidemic curve was shaped like ‘propagated epidemic curve’. The daily Rt based on Rt_c peaked to 2.6 on February 20, 2020, then showed decreased trend and became <1.0 from March 3, 2020. Comparing both Rt from Rt_c and from the number of daily onset cases, we found that the pattern of changes was similar, although the variation of Rt was greater when using Rt_c. When we changed assumed onset date for asymptotic cases (-2 days to +2 days of the confirmed date), the results were comparable. @*CONCLUSIONS@#Rt can be estimated based on Rt_c which is available from daily report of the Korea Centers for Disease Control and Prevention. Estimation of Rt would be useful to continuously monitor the effectiveness of the quarantine policy at the city and province levels.

Validation of the Korean Version of the 15-Item CommunityAssessment of Psychic Experiences in a College Population

Objective@#To investigate the reliability and validity of the Korean version of the Community Assessment of Psychic Experiences-15item positive scale (CAPE-15) in college students. @*Methods@#This study had two stages: initial screening with self-report questionnaires including the CAPE-15, and semi-structured interviewsto investigate the instrument’s diagnostic validity. The initial screening involved 1,749 college students. The modified Korean versionof Prodromal Questionnaire-16 item (mKPQ-16) was also administered. The criteria for ultra-high risk (UHR) of psychosis in theComprehensive Assessment of At-Risk Mental States (CAARMS) were the gold standard for diagnosis. @*Results@#Twelve of the interviewed subjects met the CAARMS criteria for UHR of psychosis. The area under the receiver operating characteristiccurve was highest (0.936) for the CAPE-15 distress score (p<0.001). The use of 6 as the cutoff for the CAPE-15 distress score resultedin the best balance of sensitivity (91.7%) and specificity (85.2%), with a favorable positive predictive value of 32.4%. The coefficientsof correlation between the CAPE-15 and mKPQ-16 were significant. @*Conclusion@#The Korean version of the CAPE-15 is a good instrument for screening for psychosis risk in collegiate settings. The validationof this scale could contribute to the early identification of psychosis in the Korean community. Psychiatry Investig 2020;17(4):306-311

Application of Testing-TracingTreatment Strategy in Response to the COVID-19 Outbreak in Seoul, Korea

Background@#Following the coronavirus disease 2019 (COVID-19) outbreak in Wuhan, China, a total of 637 patients had been diagnosed with the disease in Seoul as of May 2, 2020. Our study aimed to describe the impact of the 3T strategies (preemptive testing, prompt tracing and proper treatment) on the epidemiological characteristics of COVID-19 in Seoul. @*Methods@#The descriptive and explanatory analysis was carried out on critical indicators such as epidemiological characteristics and key duration of patient status change from January 24 to May 2 in Seoul before and after preemptive testing for patients under investigation associated with COVID-19 clusters. @*Results@#Preemptive testing increased the positive test rate (3.9% to 4.2%), an asymptomatic case at diagnosis (16.9% to 30.6%), and reduced the time from symptom onset to quarantine (4.0 to 3.0 days). Prompt tracing decreased unknown sources of infection (6.9% to 2.8%), the mean number of contacts (32.2 to 23.6), and the time-varying reproduction number R(t) (1.3 to 0.6). With proper treatment, only 2 cases of mortality occurred, resulting in a fatality rate of just 0.3%. @*Conclusion@#In the first wave of the COVID-19 pandemic lasting 100 days, the effect of the 3T strategies flattened the curve and decreased the time during which infected individuals were contagious, thereby lowering the R(t) below 1 in Seoul.

Introduction of Community-Based Preconception Care for Men and Women of Childbearing Age in Seoul

Community-based preconception care for men and women of childbearing age has been introduced in Seoul. The program aims to focus on problem areas such as low birth rate, fertility issues potentially due to late marriages, preterm or premature births, and low-birthweight in newborn babies. The district administration officials of Seoul, as well as, academics from the Korean Society of Maternal and Child Health, developed a protocol by using a questionnaire and laboratory test for screening risk factors in pregnancy. The protocol was tested on a trial basis in four local districts in Seoul from July 2017 to 2018, extended to 12 local districts in 2019, and all 25 districts in Seoul in 2020. The protocol includes AntiMullerian Hormone tests to assess women’s ovarian reserve and male health checkups that include semen analysis and physical examinations of genitalia. These tests are conducted for early detection and treatment of infertility, especially in cases of late marriages. In order to prevent women being abandoned during pregnancy (leading them to single-parenting), the protocol also emphasizes building a gender-sen sitive environment by encouraging more male participation. A monitoring group comprised of Seoul city district officials and academics from the Korean Society of Maternal and Child Health, regularly visited the local districts to observe improvements and keep the program officials up to date. In addition, the group also conducted a mobile phone survey for feedback on the program. The interest and support of the resi dents in Seoul city, and positive results and development in pregnancy care and childbirth, are needed to stabilize and extend this protocol.

Time-variant reproductive number of COVID-19 in Seoul, Korea / 한국역학회지

OBJECTIVES@#To estimate time-variant reproductive number (Rt) of coronavirus disease 19 based on either number of daily confirmed cases or their onset date to monitor effectiveness of quarantine policies. @*METHODS@#Using number of daily confirmed cases from January 23, 2020 to March 22, 2020 and their symptom onset date from the official website of the Seoul Metropolitan Government and the district office, we calculated Rt using program R’s package “EpiEstim”. For asymptomatic cases, their symptom onset date was considered as -2, -1, 0, +1, and +2 days of confirmed date. @*RESULTS@#Based on the information of 313 confirmed cases, the epidemic curve was shaped like ‘propagated epidemic curve’. The daily Rt based on Rt_c peaked to 2.6 on February 20, 2020, then showed decreased trend and became <1.0 from March 3, 2020. Comparing both Rt from Rt_c and from the number of daily onset cases, we found that the pattern of changes was similar, although the variation of Rt was greater when using Rt_c. When we changed assumed onset date for asymptotic cases (-2 days to +2 days of the confirmed date), the results were comparable. @*CONCLUSIONS@#Rt can be estimated based on Rt_c which is available from daily report of the Korea Centers for Disease Control and Prevention. Estimation of Rt would be useful to continuously monitor the effectiveness of the quarantine policy at the city and province levels.

The Diagnostic Utility of Prone Position Chest CT for the Evaluation of Esophageal Cancer / 전남의대학술지

The aim of this study was to assess the potential of a prone chest CT for the evaluation of esophageal cancer, as compared with a routine supine chest CT. 69 patients (67±18 years old) with pathologically confirmed esophageal cancers underwent MDCT in the supine and prone positions. The supine CT was performed first, followed by the prone position. Localization and staging of individual esophageal lesions on both the prone and supine CTs were assessed by two thoracic radiologists, using a scoring system that consisted of three confidence scales, and the results were correlated with the endoscopic and surgical findings. The mean confidence score for the detection of esophageal cancer was higher in the prone position (2.58±0.74) than that in the supine position (2.42±0.83) with statistical significance (p=0.002). The mean confidence score for predicting local invasion in the selected patients (n=18) who underwent esophagectomy was also higher in the prone position (2.39±0.85) than that in the supine position (2.06±0.73) with statistical significance (p=0.01). In 10 of 11 cases that showed definitive determination for periesophageal infiltration or adjacent organ invasion on the prone CT (score 3), the corresponding findings were also observed in the post-operative evaluations. In conclusion, prone chest CT for evaluating esophageal cancer could have advantages in regards to the localization of esophageal cancer and predicting local invasion compared to that of routine supine CT and can improve the diagnostic accuracy of chest CTs.

Effect of Inhalational Anesthetics and Positive-pressure Ventilation on Ultrasound Assessment of the Great Vessels: A Prospective Study at a Children's Hospital.

BACKGROUND: Bedside ultrasound has emerged as a rapid, noninvasive tool for assessment and monitoring of fluid status in children. The inferior vena cava (IVC) varies in size with changes in blood volume and intrathoracic pressure, but the magnitude of change to the IVC with inhalational anesthetic and positive-pressure ventilation (PPV) is unknown. METHODS: Prospective observational study of 24 healthy children aged 1 to 12 yr scheduled for elective surgery. Ultrasound images of the IVC and aorta were recorded at five time points: awake; spontaneous ventilation with sevoflurane by mask; intubated with peak inspiratory pressure/positive end-expiratory pressure of 15/0, 20/5, and 25/10 cm H2O. A blinded investigator measured IVC/aorta ratios (IVC/Ao) and changes in IVC diameter due to respiratory variation (IVC-RV) from the recorded videos. RESULTS: Inhalational anesthetic decreased IVC/Ao (1.1 ± 0.3 vs. 0.6 ± 0.2; P < 0.001) but did not change IVC-RV (median, 43%; interquartile range [IQR], 36 to 58% vs. 46%; IQR, 36 to 66%; P > 0.99). The initiation of PPV increased IVC/Ao (0.64 ± 0.21 vs. 1.16 ± 0.27; P < 0.001) and decreased IVC-RV (median, 46%; IQR, 36 to 66% vs. 9%; IQR, 4 to 14%; P < 0.001). There was no change in either IVC/Ao or IVC-RV with subsequent incremental increases in peak inspiratory pressure/positive end-expiratory pressure (P > 0.99 for both). CONCLUSIONS: Addition of inhalational anesthetic affects IVC/Ao but not IVC-RV, and significant changes in IVC/Ao and IVC-RV occur with initiation of PPV in healthy children. Clinicians should be aware of these expected vascular changes when managing patients. Establishing these IVC parameters will enable future studies to better evaluate these measurements as tools for diagnosing hypovolemia or predicting fluid responsiveness.

Why Women Living in an Obstetric Care Underserved Area Do Not Utilize Their Local Hospital Supported by Korean Government for Childbirth

PURPOSE: This study aimed to understand why mothers do not utilize the prenatal care and delivery services at their local hospital supported by the government program, the Supporting Program for Obstetric Care Underserved Area (SPOU). METHODS: We conducted a focus group interview by recruiting four mothers who delivered in the hospital in their community (a rural underserved obstetric care area) and another four mothers who delivered in the hospital outside of the community. RESULTS: From the finding, the mothers were not satisfied with the quality of services that the community hospital provided, in terms of professionalism of the obstetric care team, and the outdated medical device and facilities. Also, the mothers believed that the hospital in the metropolitan city is better for their health as well as that of their babies. The mothers who delivered in the outside community hospital considered geographical closeness less than they did the quality of obstetric care. The mothers who delivered in the community hospital gave the reason why they chose the hospital, which was convenience and emergency preparedness due to its geographical closeness. However, they were not satisfied with the quality of services provided by the community hospital like the other mothers who delivered in the hospital outside of the community. CONCLUSIONS: Therefore, in order to successfully deliver the SPOU program, the Korean government should make an effort in increasing the quality of maternity service provided in the community hospital and improving the physical factors of a community hospital such as outdated medical equipment and facilities.

Risk factors and outcomes of acute renal infarction

BACKGROUND: Renal infarction (RI) is an uncommon disease that is difficult to diagnose. As little is known about clinical characteristics of this disease, we investigated its underlying risk factors and outcomes. METHODS: We performed a retrospective single-center study of 89 patients newly diagnosed with acute RI between January 2002 and March 2015 using imaging modalities. Clinical features, possible etiologies, and long-term renal outcome data were reviewed. RESULTS: The patients' mean age was 63.5 ± 15.42 years; 23.6% had diabetes and 56.2% had hypertension. Unilateral and bilateral involvements were shown in 80.9% and 19.1% of patients, respectively; proteinuria and hematuria were reported in 40.4% and 41.6%, respectively. Cardiovascular disease was the most common underlying disease, followed by renal vascular injury and hypercoagulability disorder. Fourteen patients had no specific underlying disease. At the time of diagnosis, acute kidney injury (AKI) was found in 34.8% of patients. Univariate analysis revealed diabetes mellitus (DM), leukocytosis, and high C-reactive protein (CRP) as significant risk factors for the development of AKI. On multivariate analysis, DM and high CRP levels were independent predictors for AKI. During follow-up, chronic kidney disease developed in 27.4% of patients. Univariate and multivariate Cox regression analyses showed old age to be an independent risk factor for this disease, whereas AKI history was a negative risk factor. CONCLUSION: DM patients or those with high CRP levels should be observed for renal function deterioration. Clinicians should also monitor for RI in elderly patients.

Anti-interleukin-33 Reduces Ovalbumin-Induced Nephrotoxicity and Expression of Kidney Injury Molecule-1 / 대한배뇨장애요실금학회지

PURPOSE: To evaluate the effect of anti-interleukin-33 (anti-IL-33) on a mouse model of ovalbumin (OVA)-induced acute kidney injury (AKI). METHODS: Twenty-four female BALB/c mice were assigned to 4 groups: group A (control, n=6) was administered sterile saline intraperitoneally (i.p.) and intranasally (i.n.); group B (allergic, n=6) was administered i.p./i.n. OVA challenge; group C (null treatment, n=6) was administered control IgG i.p. before OVA challenge; and group D (anti-IL-33, n=6) was pretreated with 3.6 µg of anti-IL-33 i.p. before every OVA challenge. The following were evaluated after sacrifice: serum blood urea nitrogen and creatinine levels, Kidney injury molecule-1 gene (Kim-1) and protein (KIM-1) expression in renal parenchyma, and expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), phosphorylated endothelial NOS (p-eNOS), and phosphorylated AMP kinase (p-AMPK) proteins in renal parenchyma. RESULTS: After OVA injection and intranasal challenge, mice in groups B and C showed significant increases in the expression of Kim-1 at both the mRNA and protein levels. After anti-IL-33 treatment, mice in group D showed significant Kim-1 down-regulation at the mRNA and protein levels. Group D also showed significantly lower COX-2 protein expression, marginally lesser iNOS expression than groups B and C, and p-eNOS and p-AMPK expression at baseline levels. CONCLUSIONS: Kim-1 could be a useful marker for detecting early-stage renal injury in mouse models of OVA-induced AKI. Further, anti-IL-33 might have beneficial effects on these mouse models.

Development and Adjustment of Indicators for Underserved Area / 보건행정학회지

Underserved area is a region that has a lack of healthcare resources. In the context of Korea, however, there are not enough detailed criteria for underserved areas. In this study, we aimed to develop indicators for underserved area through Delphi technique. We systematically reviewed the existing measure of underserved area. Sixty indicators were extracted as candidates across four domains in secondary medical care. Four domains are demand, medical resource, quality of care, and health outcome. To develop indicator, two round Delphi survey was conducted among 15 professional experts such as professionals and public administrators. In conclusion, 2 final indicators (accessibility, medical utilization) was determined as an appropriate measure in order to designate underserved area for secondary medical services. Using our criteria from Delphi technique, 36 areas were found as underserved areas for the secondary medical care.