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Abstract Pancreatic ductal adenocarcinoma (PDAC) is associated with poor prognosis even without distant metastases, necessitating in-depth characterization of primary tumors for survival prediction. We assessed the feasibility of using FDG-PET/CT radiomics to predict overall survival (OS) in PDAC. This retrospective study included PDAC patients without distant metastasis who underwent FDG-PET/CT for initial staging. Primary tumors were segmented from FDG-PET/CT images, extracting 222 radiomics features. A radiomics-based risk score (Rad-score) was developed using Cox proportional hazards regression with LASSO to predict OS. The prognostic performance of the Rad-score was compared with a clinical model (demographics, disease stage, laboratory results) using Harrell’s concordance index (C-index) and bootstrapping. 140 patients were included, with a mortality rate was 72.9% during follow-up (total population, 19.5 ± 19.2 months; survivors, 34.4 ± 28.8 months). Eleven radiomics features were significant for survival prediction. The Rad-score predicted OS with a C-index of 0.681 [95% CI, 0.632–0.731]. A model integrating clinical parameters and Rad-score outperformed the clinical-only model in predicting OS (C-index 0.740 [0.715–0.816] vs. 0.673 [0.650–0.766]; C-index difference 0.067 [0.014–0.113]; P

Abstract Background Obesity has been suggested to be associated with the coronavirus disease 2019 (COVID-19); however, it is unclear whether obesity or metabolic abnormalities accompanied by obesity have a stronger association with COVID-19 risk. Methods This study used the Korea Disease Control and Prevention Agency database, which includes information about the COVID-19 diagnosis and mortality dates of the entire Korean population between October 2020 and December 2021 (for diagnosis) or March 2022 (for mortality). A total of 24,310,283 adults were included and classified into four metabolic obesity phenotypes: (1) metabolically healthy and normal weight (MHNW), (2) metabolically unhealthy and normal weight (MUNW), (3) metabolically healthy and obese (MHO), and (4) metabolically unhealthy and obese (MUO). COVID-19 mortality and severity were compared according to metabolic obesity phenotypes in the total population and in each age group (20–

Abstract The waiting time to deceased-donor kidney transplantation (DDKT) is long in Asian countries. We investigated the impact of sensitization and ABO blood type (ABO) on DDKT opportunity using two Korean cohorts: a hospital cohort from two centers and a national database. The impact of panel reactive antibody (PRA) based on the maximal PRA% and ABO on DDKT accessibility was analyzed using a competing risks regression model. In the hospital cohort (n = 4722), 88.2%, 8.7%, and 3.1% of patients belonged to

Fishing is considered one of the most dangerous industries alongside mining that needs further efforts to improve safety. In this study, we have investigated safety management of the gillnet fishing industry in South Korea through identifying safety level and classifying common accident types from the statements of accident com-pensation insurance payments for the last 5 years (2016-2020). There were in total 3,895 accidents and 159 fatalities with an average accident frequency of 5.34 × 10−2 per year per fisher and an average fatality of 2.18 × 10−3 fishers per year. We have also identified that 62.4% of the accidents occurred during Fishing (FS), and the most common and the most severe accident type is Slips and Trips (ST) and Other (OT) marine accidents such as collision and capsizing, respectively. The hand was most frequently injured. Finally, the risk assessment indicated that most of the accident types of gillnet fishing in South Korea have unacceptable levels of risks, and it is urgent to implement improved safety measures to reduce accidents during gillnet fishing operation. The findings of this study are expected to provide valuable data to create a safer working environment for fishers working on gillnet fishing vessels.

The gut microbiota can play an important role in enhancing the host’s complex immune system. In this regard, many studies indicate that probiotics consumption has a beneficial impact on alterations in the composition of the gut microbiota. Our previous study demonstrated that the oral administration of Lacticaseibacillus rhamnosus HDB1258 (HDB1258) enhances immune cell activity and alters the composition of gut microbiota in C57BL/6 mice, thereby showing its potential as a novel immunostimulatory ingredient. Therefore, this clinical trial assessed the effects of HDB1258 on human natural killer (NK) cell activity and changes in gut microbiota. It also investigated the correlation between gut microbiota and NK cell activity following HDB1258 supplementation. Participants (n = 71) were randomized into placebo and HDB1258 groups, and NK cell activity and gut microbiota were investigated at baseline (week 0) and endline (week 8). The present study showed that HDB1258 significantly increased NK cell activity and resulted in positive regulatory effects on the gut microbial balance in subjects compared to the placebo group. HDB1258 affected the gut microbial balance by inducing the growth of beneficial bacteria such as Lactococcus and Sutterella. Especially, the changes in Escherichia–Shigella composition were negatively correlated with the changes in NK cell activity after HDB1258 consumption. There was also a positive correlation between the NK cell activity in the HDB1258 group and the composition of Prevotella 9 and Adlercreutzia. These findings suggest that HDB1258 may improve the host’s intestinal environment by regulating gut bacteria related to immune response and promote NK cell activation. This study was registered at clinical research information service (CRIS: KCT0008204).

Abstract Magnesium ferrite (MF0.33) impregnated flower-shaped mesoporous ordered silica foam (MOSF) was successfully synthesized in present study. MOSF was added with precursor solution of MF0.33 during MF0.33 synthesis which soaked the materials and further chemical changes occurred inside the pore. Therefore, no additional synthesis process was required for magnesium ferrite impregnated mesoporous ordered silica foam (MF0.33-MOSF) synthesis. MF0.33-MOSF showed higher morphological properties compared to other magnesium ferrite modified nanomaterials and adsorbed arsenic III [As(III)] and arsenic V [As(V)] 42.80 and 39.73 mg/g respectively. These were higher than those of other Fe-modified adsorbents at pH 7. As MOSF has no adsorption capacity, MF0.33 played key role to adsorb arsenic by MF0.33-MOSF. Data showed that MF0.33-MOSF contain about 2.5 times lower Fe and Mg than pure MF0.33 which was affected the arsenic adsorption capacity by MF0.33-MOSF. Adsorption results best fitted with Freundlich isotherm model. The possible mechanism of arsenic adsorption might be chemisorption by electrostatic attraction and inner or outer-sphere surface complex formation.

Abstract Although aptamers have shown excellent target specificity in preclinical and clinical studies either by themselves or as aptamer‐drug conjugates, their in vivo tissue pharmacokinetic (PK) analysis is still problematic. We aimed to examine the utility of image‐based positron emission tomography (PET) to evaluate in vivo tissue PK, target specificity, and applicability of oligonucleotides. For this, fluorine‐18‐labeled aptamers with erb‐b2 receptor tyrosine kinase 2 (ERBB2)‐specific binding were synthesized by base‐pair hybridization using a complementary oligonucleotide platform. To investigate the PKs and properties of in vivo tissue, usefulness of in vivo PET imaging in the development of an oligonucleotide‐based drug as an assessment tool was evaluated in normal and tumor xenografted mice. ERBB2‐cODN‐idT‐APs‐[18F]F ([18F]1), injected intravenously showed significant and rapid uptake in most tissues except for the initial brain and muscle; the uptake was highest in the heart, followed by kidneys, liver, lungs, gall bladder, spleen, and stomach. The main route of excretion was through the renal tract ~77.8%, whereas about 8.3% was through the biliary tract of the total dose. The estimated effective dose for an adult woman was 0.00189 mGy/MBq, which might be safe. ERBB2‐positive tumor could be well visualized in the KPL4 xenograft animal model by in vivo PET imaging. Consequently, the distribution in each organ including ERBB2 expression could be well determined and quantified by PET with fluorine‐18‐labeled aptamers. In vivo PK parameters such as terminal half‐life, time to maximum concentration, area under the curve, and maximum concentration, were also successfully estimated. These results suggest that image‐based PET with radioisotope‐labeled aptamers could be provide valuable information on properties of oligonucleotide‐based drugs in drug discovery of targeted therapeutics against various diseases.

The goal of the 8th edition of the Clinical Practice Guidelines for Obesity is to help primary care physician provide safe, effective care to patients with obesity by offering evidence-based recommendations to improve the quality of treatment. The Committee for Clinical Practice Guidelines comprised individuals with multidisciplinary expertise in obesity management. A steering board of seven experts oversaw the entire project. Recommendations were developed as the answers to key questions formulated in patient/problem, intervention, comparison, outcomes (PICO) format. Guidelines underwent multi-level review and cross-checking and received endorsement from relevant scientific societies. This edition of the guidelines includes criteria for diagnosing obesity, abdominal obesity, and metabolic syndrome; evaluation of obesity and its complications; weight loss goals; and treatment options such as diet, exercise, behavioral therapy, pharmacotherapy, and bariatric and metabolic surgery for Korean people with obesity. Compared to the previous edition of the guidelines, the current edition includes five new topics to keep up with the constantly evolving field of obesity: diagnosis of obesity, obesity in women, obesity in patients with mental illness, weight maintenance after weight loss, and the use of information and communication technology-based interventions for obesity treatment. This edition of the guidelines features has improved organization, more clearly linking key questions in PICO format to recommendations and key references. We are confident that these new Clinical Practice Guidelines for Obesity will be a valuable resource for all healthcare professionals as they describe the most current and evidence-based treatment options for obesity in a well-organized format.

Background: Glaceum Inc. has proposed HSG4112, a structural analogue of glabridin, as a novel anti-obesity compound. Animal studies and phase I human trials have shown that HSG4112 improves energy consumption, normalises weight, and is safe and drug-resistant. Based on these results, the company plans to conduct a phase 2a clinical trial to determine the safety and efficacy of HSG4112 in overweight and obese patients. Methods: A 16-week randomised, double-blind, placebo-controlled, parallel-group trial will be conducted at five large hospitals in South Korea to assess the safety and efficacy of HSG4112 in overweight and obese patients. Participants who meet the inclusion/exclusion criteria will be assigned a subject number and randomly assigned to one of the four treatment groups (one group receiving a placebo) in a 1:1:1:1 ratio. The study’s primary outcome will be to monitor the change in body weight (kg) from baseline to the end of treatment while monitoring safety and tolerability. Discussion: This trial will evaluate the efficacy and safety of HSG4112 in overweight and obese adults. Upon proving the safety and effectiveness of the newly developed mechanism, it might significantly improve the perception of the product among medical personnel and obese patients. Furthermore, it may aid in managing chronic conditions that require long-term treatment.Trial registration:ClinicalTrials.gov, identifier [NCT05197556].

Loss of excitatory synapses occur prior to the formation of amyloid plaques in Alzheimer’s disease. Here the authors show in an animal model that the loss of synapses induced by amyloid-beta oligomers requires over-activation of a stress-response pathway inducing structural remodelling of mitochondria in dendrites of cortical and hippocampal neurons.

Background As the need for a nationwide organ-transplant registry emerged, a prospective registry, the Korean Organ Transplantation Registry (KOTRY), was initiated in 2014. Here, we present baseline characteristics and outcomes of the kidney-transplant cohort for 2014 through 2019. Methods The KOTRY consists of five organ-transplant cohorts (kidney, liver, lung, heart, and pancreas). Data and samples were prospectively collected from transplant recipients and donors at baseline and follow-up visits; and epidemiological trends, allograft outcomes, and patient outcomes, such as posttransplant complications, comorbidities, and mortality, were analyzed. Results From 2014 to 2019, there were a total of 6,129 registered kidney transplants (64.8% with living donors and 35.2% with deceased donors) with a mean recipient age of 49.4 ± 11.5 years, and 59.7% were male. ABO-incompatible transplants totaled 17.4% of all transplants, and 15.0% of transplants were preemptive. The overall 1- and 5-year patient survival rates were 98.4% and 95.8%, respectively, and the 1- and 5-year graft survival rates were 97.1% and 90.5%, respectively. During a mean follow-up of 3.8 years, biopsy-proven acute rejection episodes occurred in 17.0% of cases. The mean age of donors was 47.3 ± 12.9 years, and 52.6% were male. Among living donors, the largest category of donors was spouses, while, among deceased donors, 31.2% were expanded-criteria donors. The mean serum creatinine concentrations of living donors were 0.78 ± 0.62 mg/dL and 1.09 ± 0.24 mg/dL at baseline and 1 year after kidney transplantation, respectively. Conclusion The KOTRY, a systematic Korean transplant cohort, can serve as a valuable epidemiological database of Korean kidney transplants.

Abstract Late Pneumocystis jirovecii pneumonia (PJP) is not rare in the era of universal prophylaxis after kidney transplantation. We aimed to determine the nationwide status of PJP prophylaxis in Korea and compare the incidence, risk factors, and outcomes of early and late PJP using data from the Korean Organ Transplantation Registry (KOTRY), a nationwide Korean transplant cohort. We conducted a retrospective analysis using data of 4,839 kidney transplant patients from KOTRY between 2014 and 2018, excluding patients who received multi-organ transplantation or were under 18 years old. Cox regression analysis was performed to determine risk factors for early and late PJP. A total of 50 patients developed PJP. The number of patients who developed PJP was same between onset before 6 months and onsets after 6 months. There were no differences in the rate, duration, or dose of PJP prophylaxis between early and late PJP. Desensitization, higher tacrolimus dose at discharge, and acute rejection were associated with early PJP. In late PJP, old age as well as acute rejection were significant risk factors. In conclusion late PJP is as common and risky as early PJP and requires individualized risk-based prophylaxis, such as prolonged prophylaxis for old patients with a history of rejection.

Abstract Data for Asian kidney transplants are very limited. We investigated the relative importance of prognostic markers in Asian kidney transplants by using Korean Organ Transplantation Registry (KOTRY) cohort. Prediction models were developed by data-driven variable selection approach. The relative importance of the selected predictors was measured by dominance analysis. A total of 4854 kidney transplant donor-recipient pairs were analyzed. Overall patient survival rates were 99.8%, 98.8%, and 91.8% at 1, 3, and 5 years, respectively. Death-censored graft survival rates were 98.4%, 97.0%, and 95.8% at 1, 3, and 5 years. Biopsy-proven acute rejection free survival rates were 90.1%, 87.4%, and 87.03% at 1, 3, and 5 years. The top 3 dominant predictors for recipient mortality within 1 year were recipient cardiovascular disease history, deceased donor, and recipient age. The dominant predictors for death-censored graft loss within 1 year were acute rejection, deceased donor, and desensitization. The dominant predictors to acute rejection within 1 year were donor age, HLA mismatched numbers, and desensitization. We presented clinical characteristics of patients enrolled in KOTRY during the last 5 years and investigated dominant predictors for early post-transplant outcomes, which would be useful for clinical decision-making based on quantitative measures.

Hemangioblastoma (HB) is a rare benign tumor that most commonly occurs in the cerebellum. HB is composed of neoplastic stromal cells and abundant small vessels. However, the exact origin of stromal cells is controversial. Extraneural HBs have been reported in a small series, and peripheral HBs arising in the adrenal gland are extremely rare. Herein, we report a case of sporadic adrenal HB in a 54-year-old woman. The tumor was a well-circumscribed, yellow mass measuring 4.2 cm in diameter. Histologically, the tumor was composed of small blood vessels and vacuolated stromal cells with clear cytoplasm. On immunohistochemical stain, the stromal cells were positive for S-100 protein, neuron-specific enolase, and synaptophysin. The tumor did not reveal mutation of VHL alleles. We herein present a case of HB of the adrenal gland and review of the literature.

We develop a model of bailout stigma in which accepting a bailout signals a firm's balance‐sheet weakness and reduces its funding prospects. To avoid stigma, high‐quality firms withdraw from subsequent financing after receiving bailouts or refuse bailouts altogether to send a favorable signal. The former leads to a short‐lived stimulation followed by a market freeze even worse than if there were no bailout. The latter revives the funding market, albeit with delay, to the level achievable without any stigma and implements a constrained optimal outcome. A menu of multiple bailout programs compounds bailout stigma and exacerbates the market freeze. [ABSTRACT FROM AUTHOR]

Abstract Since the waiting time for deceased donor kidney transplantation continues to increase, living donor kidney transplantation is an important treatment for end stage kidney disease patients. Barriers to living kidney donation have been rarely investigated despite a growing interest in the utilization of living donor transplantation and the satisfaction of donor safety. Here, we retrospectively analyzed 1658 potential donors and 1273 potential recipients who visited the Seoul National University Hospital for living kidney transplantation between 2010 and 2017 to study the causes of donation discontinuation. Among 1658 potential donors, 902 (54.4%) failed to donate kidneys. The average number of potential donors that received work-up was 1.30 ± 0.66 per recipient. Among living donor kidney transplant patients, 75.1% received kidneys after work-up of the first donor and 24.9% needed work-up of two or more donors. Donor-related factors (49.2%) were the most common causes of donation discontinuation, followed by immunologic or size mismatches between donors and recipients (25.4%) and recipient-related factors (16.2%). Interestingly, withdrawal of donation consent along with refusal by recipients or family were the commonest causes, suggesting the importance of non-biomedical aspects. The elucidation of the barriers to living kidney donation could ensure more efficient and safer living kidney donation.

Abstract We evaluated the association between aspirin, statins, and metformin use and prostate cancer (PC) incidence and mortality using a large population-based dataset. 388,760 men who participated in national health screening program in Korea during 2002–2003 were observed from 2004 to 2013. Hazard ratios of aspirin, statins, and metformin use for PC incidence and PC mortality were calculated with adjustment for simultaneous drug use. Cumulative use of each drug was inserted as time-dependent variable with 2-year time windows. Aspirin use ≥ 1.5 year (per 2-year) was associated with borderline decrease in PC mortality when compared to non-users (adjusted hazard ratio [aHR] 0.71, 95% confidence interval [CI] 0.50–1.02). Statins use was not associated with either PC incidence or PC mortality. Metformin ever-use was associated with decreased PC incidence compared with non-diabetics (aHR 0.86, 95% CI 0.77–0.96). Diabetics who were not using metformin or using low cumulative doses had higher PC mortality than non-diabetics (aHR 2.01, 95% CI 1.44–2.81, and aHR 1.70, 95% CI 1.07–2.69, respectively). However, subjects with higher cumulative doses of metformin did not show increased PC mortality. In conclusion, metformin use was associated with lower PC incidence. Use of aspirin and that of metformin among diabetic patients were associated with lower PC mortality.

Background : The new kidney allocation system in the United States has introduced longevity matching, which gives priority to allocating the best quality organs to wait-listed candidates with the longest predicted survival for the efficient utilization of organs that are of limited availability. The estimated post-transplant survival (EPTS) score was developed in the United States to risk-stratify all wait-listed patients. However, prognostic indices used in Western countries were derived from data that may be different for Korea and do not necessarily reflect prognostic values for Korean deceased donor kidney transplantation. Prognostic indices for Korean wait-listed candidates therefore need to be developed from Korean data. Methods : We analyzed 6,731 adult solitary kidney transplant patients for candidate risk prediction using the national data from the Korean Network for Organ Sharing (KONOS) and National Health Insurance Data Sharing Service (NHISS). Cox regression analysis was used to model the risk of patient death. Results : The Korean EPTS (K-EPTS) score was developed based on four recipient parameters (age, diabetes mellitus, hepatitis C virus, and duration of dialysis) that showed a significant association with post-transplant survival. K-EPTS scores showed good discrimination (C-statistics: 0.690; 95% confidence interval, 0.666–0.715). Moreover, the ability of the K-EPTS score to discriminate patient survival was better than that of the EPTS according to the criteria of the United Network for Organ Sharing (US-EPTS) score (P

Purpose: Mediastinal nodal staging is crucial for surgical candidate selection in non-small cell lung cancer (NSCLC), but conventional imaging has limitations often necessitating invasive staging. We investigated the additive clinical value of fibroblast activation protein inhibitor (FAPI) PET/CT, an imaging technique targeting fibroblast activation protein, for mediastinal nodal staging of NSCLC. Methods: In this prospective pilot study, we enrolled patients scheduled for surgical resection of NSCLC based on specific criteria designed to align with indications for invasive staging procedures. Patients were included when meeting at least one of the following: (1) presence of FDG-positive N2 lymph nodes, (2) clinical N1 stage, (3) central tumor location or tumor diameter of ≥ 3 cm, and (4) adenocarcinoma exhibiting high FDG uptake. [68Ga]FAPI-46 PET/CT was performed before surgery after a staging workup including [18F]FDG PET/CT. The diagnostic accuracy of [68Ga]FAPI-46 PET/CT for "N2" nodes was assessed through per-patient visual assessment and per-station quantitative analysis using histopathologic results as reference standards. Results: Twenty-three patients with 75 nodal stations were analyzed. Histopathologic examination confirmed that nine patients (39.1%) were N2-positive. In per-patient assessment, [68Ga]FAPI-46 PET/CT successfully identified metastasis in eight patients (sensitivity 0.89 (0.52–1.00)), upstaging three patients compared to [18F]FDG PET/CT. [18F]FDG PET/CT detected FDG-avid nodes in six (42.8%) of 14 N2-negative patients. Among them, five were considered non-metastatic based on calcification and distribution pattern, and one was considered metastatic. In contrast, [68Ga]FAPI-46 PET/CT correctly identified all non-metastatic patients solely based on tracer avidity. In per-station analysis, [68Ga]FAPI-46 PET/CT discriminated metastasis more effectively compared to [18F]FDG PET/CT-based (AUC of ROC curve 0.96 (0.88–0.99) vs. 0.68 (0.56–0.78), P < 0.001). Conclusion: [68Ga]FAPI-46 PET/CT holds promise as an imaging tool for preoperative mediastinal nodal staging in NSCLC, with improved sensitivity and the potential to reduce false-positive results, optimizing the need for invasive staging procedures. [ABSTRACT FROM AUTHOR]

Objectives:By measuring the solids loading rate for the sidestream, it was intended to achieve increased treatment capacity and improved process performance by developing control technologies for primary sludge removal, recirculation, and input. Methods:The pilot plant was manufactured by the primary clarifier+MLE process similar to the full-scale plant and was configured to control the amount of sludge withdrawal based on the inflow solids loading rate. The state point analysis was used to determine removal underflow withdrawal rate and the total underflow withdrawal rate for the primary sludge. The operation was divided into manual withdrawal, automatic withdrawal, automatic withdrawal+recirculation, and automatic withdrawal+input methods. The performance evaluation items for primary sludge control technology were primary sludge concentration and SS removal efficiency for primary and secondary clarifiers. The improvement in the performance of the bioreactor by recirculation and input was judged through the removal efficiency of ammonium nitrogen, TIN (Total Inorganic Nitrogen) and phosphate phosphorus, SNR (Specific Nitrification Rate), and SDNR (Specific Denitrification Rate). The cause of the performance improvement was analyzed by comparing the acetic acid concentration changed by recirculation and the microbial community characteristics. Results and Discussion:The average value of SS monitoring of the sidestream influent was 2.2 (0.7~6.3) g/L and the primary clarifier needed treatment in response to high concentration SS and fluctuations. It is judged that the state point analysis based on the actual settling rate can accurately suggest whether the stable operation of primary sludge removal, recirculation, and input is the possible and specific design and operation standards. The automatic withdrawal that controls the underflow withdrawal rate according to the change of the inflow solids loading rate could stably draw out the high-concentration sludge and maintain the SS removal efficiency. It is believed that stable operation is possible even in the sludge recirculation operation, and the treatment capacity of the primary clarifier can be increased more than two times in a full-scale plant. By recirculation of the primary sludge, the TIN removal efficiency in the bioreactor was improved by 24.2~52.3%, and the phosphate phosphorus removal efficiency was improved by up to 20.1%. The TIN removal efficiency in the bioreactor was improved by 32.6% by the input of primary sludge. VFAs (Volatile Fatty Acids) including acetic acid was produced and the removal efficiency was improved because it was in contact with primary sludge by recirculation and the ratio of major fermentation microorganisms was present at 2.0%. It is determined that 26.4% of the main species of microorganisms treated with nitrogen and phosphorus exist in the sidestream inflow and the removal efficiency was improved by supplying microorganisms through the input of primary sludge. Conclusions:Technology that controls primary sludge removal, recirculation, and input by measuring the solids loading rate for the sidestream is believed to increase the treatment capacity of the primary clarifier and improve the nitrogen and phosphorus removal efficiency of the bioreactor.

Objectives:This study aimed to achieve improved process performance and energy saving by developing a technology to control the air supply of an aerobic basin by measuring the conductivity in the anoxic basin. Methods:To verify whether conductivity can be used as an operation indicator of biological treatment, the correlation analysis between water quality factor and conductivity of each process was conducted by dividing into summer (methanol input), winter and autumn periods. An empirical formula was presented by briefly arranging the required air quantity formula, and a quick reference was prepared by putting air supply in the conductivity range sequentially. The performance evaluation was judged based on the removal efficiency of ammonia nitrogen and total inorganic nitrogen, SNR and SDNR, the change of air supply, the stability of the process against inflow change. Results and Discussion:The seasonal correlation coefficients of conductivity and water quality items were calculated in the order of ammonia nitrogen, total inorganic nitrogen, DOC, and phosphate in the range of 0.5267~0.9115. It was found that the conductivity could be used as an operation indicator of the biological treatment process with a correlation coefficient of 0.5 or more. The regression equations for the conductivity and ammonia nitrogen are secured by season, so it is possible to estimate the ammonia nitrogen through the conductivity. At the end of the aerobic basin DO was 3.4 mg/L, the nitrogen treatment efficiency in winter was the best. The aerobic basin DO can be controlled by the air supply, and it can be seen that it is possible to control the air supply and improve the nitrogen treatment efficiency by directly measuring the conductivity having a high correlation with nitrogen. An empirical formula for estimating the required air volume through conductivity and inflow is presented. A' and (B' + X') are 0.0589 (m3-air/h)/(m3/h)/(µS/cm) and –77.562 (m3-air/h)/(m3/h). The result of automatic control of air supply according to the measured conductivity of anoxic tank during winter season showed that total inorganic nitrogen removal efficiency and SDNR were 8.3% and 0.007 g-N/g-MLSS/d higher than the actual plant conditions, respectively. During the automatic control period, the air supply/inflow average ratio was 36 (m3-air/h)/(m3/h), which could reduce the air supply by 21.7% compared to the actual plant conditions. Conclusions:The air supply can be estimated from the flow rate and conductivity. The air supply control technology of the conductivity-based MLE process will be able to simultaneously improve nitrogen removal efficiency and reduce energy consumption.

Abstract Background While smoking elevates the risk for cardiovascular disease (CVD) among atrial fibrillation (AF) patients, whether smoking cessation after AF diagnosis actually leads to reduced CVD risk is unclear. We aimed to determine the association of smoking cessation after AF diagnosis with subsequent CVD Risk among South Korean men. Methods This retrospective cohort study included 2372 newly diagnosed AF male patients during 2003–2012 from the Korean National Health Insurance Service database. Self-reported smoking status within 2 years before and after diagnosis date were determined, after which the participants were divided into continual smokers, quitters (smokers who quit after AF diagnosis), sustained-ex smokers (those who quit prior to AF diagnosis), and never smokers. Participants were followed up from 2 years after AF diagnosis until 31 December 2015 for CVD. Cox proportional hazards regression was used to determine the adjusted hazard ratios (aHRs) and 95% confidence interval (CIs) for CVD according to the change in smoking habits before and after AF diagnosis. Results The mean (standard deviation, minimum-maximum) age of the study subjects was 62.5 (8.6, 41–89) years. Among AF patients, quitters had 35% reduced risk (aHR 0.65, 95% CI 0.44–0.97) and never smokers had 32% reduced risk (aHR 0.68, 95% CI 0.52–0.90) for CVD compared to continual smokers (p for trend 0.020). Similarly, compared to continual smokers, quitters had 41% risk-reduction (aHR 0.59, 95% CI 0.35–0.99) and never smokers 34% risk-reduction (aHR 0.66, 95% CI 0.46–0.93) for total stroke (p for trend 0.047). Quitters had 50% reduction (aHR 0.50, 95% CI 0.27–0.94), sustained ex-smokers had 36% reduction (aHR 0.64, 95% CI 0.42–0.99), and never smokers had 39% reduction (aHR 0.61, 95% CI 0.41–0.91) in ischemic stroke risk (p for trend 0.047). The risk-reducing effect of quitting on CVD risk tended to be preserved regardless of aspirin or warfarin use. Conclusions Smoking cessation after AF diagnosis was associated with reduced CVD, total stroke, and ischemic stroke risk.