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We performed continuous long-term measurements of PM2.5 mass, comprehensive chemical composition, and optical properties, including scattering and absorption coefficients, from March 2011 to December 2020 at the Metropolitan Air Quality Research Center in Seoul, South Korea. PM2.5 peaked at 38 μg/m3 in 2013 and has been declining steadily since then, reaching 22 μg/m3 in 2020. The extinction coefficients also decreased with the decline in PM2.5, but the correlation between the two factors was not as pronounced. This deviation was mainly attributed to the rapid changes in the chemical composition of PM2.5 over the same period. The mass contribution of sulphate to PM2.5 decreased from 33.9 to 24.1%, but the fraction of nitrate and organic carbon increased from 23.4 and 20.0 to 34.1 and 32.2%, respectively, indicating that sulphate has been replaced by nitrate and organic carbon over the past decade. To assess the effect of changing aerosol chemical compositions on light extinction, we compared the measured extinction coefficients with those estimated via the various existing light extinction approaches, including the revised IMPROVE algorithm. We found that the simplified linear regression model provided the best fit to our data, with a slope of 1.03 and R2 of 0.87, and that all non-linear methods, such as the IMPROVE algorithms, overestimated the observed long-term light extinction by 23 to 48%. This suggests that the simple linear regression scheme may be more appropriate for reflecting the varying aerosol conditions over long periods of time, especially for urban air. However, for conditions where the chemical composition does not change much, non-linear methods such as the IMPROVE scheme are likely to be more appropriate for reproducing light extinction. [ABSTRACT FROM AUTHOR]

The prognostic role of the recurrence score (RS) based on the 21‐gene expression assay in premenopausal women is not well delineated, and we investigated the association of outcomes and the RS in premenopausal patients who had 21‐gene expression assay at Asan Medical Center, Seoul, Korea, between June 2005 and July 2018. Invasive breast cancer‐free survival (IBCFS) by STEEP version 2.0 was compared according to the RS and clinical risk factors. A total of 554 patients were included in our study and 116 patients (20.9%) had age <40 years, 238 patients (43.0%) had luminal B subtype (Ki67 ≥ 20%), and 83 patients (15.0%) had RS >25. All patients received adjuvant tamoxifen ± chemotherapy. Overall, patients with RS >25 showed trend toward worse IBCFS from multivariable analysis (adjusted HR 1.89 [95% CI: 0.95‐3.73], P =.069). When comparing outcomes according to age and luminal subtypes, patients with luminal B subtype and age <40 years (n = 60) showed significantly worse outcomes compared to the others (luminal A or luminal B + age ≥40 years, n = 494; adjusted HR 2.95 [95% CI: 1.49‐5.82], log‐rank P <.001). Among patients with luminal B subtype and age <40 years, there was no significant association observed between IBCFS and the RS (log‐rank P =.51). In conclusion, while RS >25 showed association with poor outcomes in premenopausal women, it may have less prognostic significance among those with luminal B subtype and age <40 years. [ABSTRACT FROM AUTHOR]

Objectives: A substantial number of hospitalized patients with terminal cancer at the end-of-life phase receive antibiotics, even with imminent death. We evaluated the impact of palliative care consultation on antibiotic use in hospitalized patients with terminal cancer during the end-of-life phase.Methods: We identified adult patients with metastatic solid cancer who died at a tertiary medical centre in Seoul, Republic of Korea, following at least 4 days of hospitalization (January 2018-December 2020). Patients were divided into palliative and non-palliative care consultation groups. Propensity score-weighted, multivariable logistic regression analysis was used to compare the proportion of patients receiving antibiotics within 3 days before death between the two groups.Results: Among 1143 patients analysed, 940 (82.2%) received antibiotics within 3 days before death. The proportion of patients receiving antibiotics was significantly lower (propensity score-weighted P < 0.001) in the palliative care consultation group (344/468; 73.5%) than in the non-palliative care consultation group (596/675; 88.3%). The decrease in the proportion of patients receiving antibiotics in the palliative care consultation group was significant for a carbapenem (42.4% versus 22.4%; P < 0.001), a glycopeptide (23.3% versus 11.1%; P < 0.001) and a quinolone (30.5% versus 19.4%; P = 0.012). In the multivariable logistic regression analysis, receiving palliative care consultation (adjusted OR 0.46, 95% CI 0.33-0.65; P < 0.001) was independently associated with reduced antibiotic use during the end-of-life phase.Conclusions: Palliative care consultation may reduce aggressive antibiotic use in hospitalized patients with terminal cancer during the end-of-life phase. [ABSTRACT FROM AUTHOR]

Ensemble deep learning methods have demonstrated significant improvements in forecasting the solar panel power generation using historical time-series data. Although many studies have used ensemble deep learning methods with various data partitioning strategies, most have only focused on improving the predictive methods by associating several different models or combining hyperparameters and interactions. In this study, we contend that we can enhance the precision of power generation forecasting by identifying a suitable data partition strategy and establishing the ideal number of partitions and subset sizes. Thus, we propose a feasibility study of the influence of data partition strategies on ensemble deep learning. We selected five time-series data partitioning strategies—window, shuffle, pyramid, vertical, and seasonal—that allow us to identify different characteristics and features in the time-series data. We conducted various experiments on two sources of solar panel datasets collected in Seoul and Gyeongju, South Korea. Additionally, LSTM-based bagging ensemble models were applied to combine the advantages of several single LSTM models. The experimental results reveal that the data partition strategies positively influence the forecasting of power generation. Specifically, the results demonstrate that ensemble models with data partition strategies outperform single LSTM models by approximately 4–11% in terms of the coefficient of determination (R2) score. [ABSTRACT FROM AUTHOR]

Background and Objectives: Recently, the single-port (SP) robotic system was introduced for minimally invasive operative techniques. Thus, this study aimed to validate the safety and feasibility of SP trans-axillary robotic thyroidectomy (SP-TART) through experiences in a single tertiary institution. Materials and Methods: This study retrospectively analyzed 100 consecutive patients who underwent SP-TART from October 2021 to June 2022 in Seoul St. Mary's Hospital in Seoul, Korea. We analyzed the clinicopathological characteristics and perioperative outcomes, including complications. Results: Less than total thyroidectomy (LTT) was performed in 81, total thyroidectomy (TT) in 16, and TT with modified radical neck dissection (mRND) in 3 patients. The mean operation time (min) was 53.3 ± 13.7, 86.3 ± 15.1, and 245.7 ± 36.7 in LTT, TT, and TT with mRND, respectively. The mean postoperative hospital stay was 2.0 ± 0.2, 2.1 ± 0.3, and 3.7 ± 1.5 days, respectively. A total of 84 cases of thyroid cancer were included, and 97.6% of them (82 cases) were papillary carcinoma and the rest were follicular and poorly differentiated carcinomas. Regarding complications, five cases had major complications, including three cases of vocal cord palsy and two cases of transient hypoparathyroidism. Conclusions: SP-TART is safe and feasible with a short operation time and a short length of hospital stay. [ABSTRACT FROM AUTHOR]

Aim: Although the incidence of urinary tract infection (UTI) in children with lower respiratory tract infection (LRTI) has been reported as 3.1–10.0%, the exact concomitant prevalence is questionable. Here, we evaluated the prevalence and related risk factors of UTI associated with LRTI in children under 36 months of age. Methods: We retrospectively reviewed the medical charts of 1574 patients under 36 months of age who were hospitalised with LRTI from January 2017 to December 2019 in a single centre, Seoul, South Korea. Among them, we analysed 278 patients who showed fever and performed urine evaluation. Urine was collected by catheterisation in children under 24 months of age and by voided urine between 24 and 36 months of age. Results: The prevalence of concomitant UTI and LRTI was 13.6% in children under 24 months of age. Mean age was significantly younger in the UTI versus non‐UTI group (6.93 ± 7.26 months vs. 12.61 ± 11.70 months; P < 0.001). When the participants were stratified by age, the prevalence of UTI was significantly higher in children younger than 24 months of age compared to older ones (P = 0.006). UTIs were more prevalent in boys than in girls (14.6% vs. 5.8%, P = 0.018). Peak body temperature, fever duration, premature birth and detected respiratory virus type did not differ between groups. Conclusions: It is not uncommon for children with LRTI with fever to be accompanied by UTI. When evaluating for UTI in children with febrile LRTI, age and sex must be considered. [ABSTRACT FROM AUTHOR]

Background: Preoperative chemoradiotherapy (pre-CRT) followed by total mesorectal excision (TME) is currently a standard therapy for locally advanced mid-to-low rectal cancer. Less aggressive, organ-preserving option such as local excision (LE) or watchful wait can alternatively be used for patients who respond well to pre-CRT. High-resolution rectal magnetic resonance imaging (MRI) is one of the most useful methods to assess pre-CRT response, and the MERCURY group has shown that the MR tumor regression grade (mrTRG) correlated with the pathologic TRG. The aim of this study is to compare postoperative complication and oncologic outcomes between LE and TME in mid-to-low rectal cancer patients whose tumors are mrTRG grade 1 (radiological complete remission) or 2 (predominant fibrosis; near-complete remission) after pre-CRT.Methods: A prospective, double-arm, randomized, open-labeled, single center, clinical trial will be conducted in patients with mid-to-low rectal cancer whose tumors are mrTRG 1/2 after pre-CRT at the Asan Medical Center, Seoul, Korea, after approval from the Institution Review Board. Patient medical records will be de-identified using a serial number to protect personal information. Inclusion criteria will include rectal adenocarcinoma with an inferior border < 8 cm from the anal verge, mrTRG 1/2, age > 20, and provision of informed consent. Postoperative complications will be assessed by Clavien-Dindo Classification Grade. Oncologic and functional outcomes will be collected and risk factors related to these outcomes will be investigated.Discussion: We believed that the rate of postoperative complication of LE will be comparable to that of TME in mid-to-low advanced rectal cancer patients with a favorable response after pre-CRT.Trial Registration: KCT0002579 ( https://cris.nih.go.kr ) Dec-2017. [ABSTRACT FROM AUTHOR]

The meteorological, physical, chemical, and optical characteristics of long-lasting haze in Seoul were studied. Four episodes were observed between 2009 and 2014, all in winter. PM10 mass concentration (PM10), chemical species, and aerosol optical depth (AOD) were analyzed along with the synoptic meteorological conditions. During the episodes, the temporal variations of the PM10 generally proceeded from the west along the Yellow Sea. The ground-based AOD was also high in Seoul and other sites. High AOD (MODIS) distributions were observed to move from China to Korea. The high sulfate concentration, along with the high sulfur oxidation ratio value of the third and fourth episodes (Eps. 3 and 4), respectively, corroborated the possible long-range transport of air pollutants. Stagnant meteorological conditions were a reason for the occurrence of long-lasting hazes. An anticyclone system had a dominant influence on the Korean peninsula during all episodes. The air mass over China was able to rise, and that over Korea was more stagnant in terms of climatology except Ep. 2. In addition to transport from outside, locally emitted air pollutants contributed to the PM10 partly due to the stagnant conditions, during which diurnal variations in NO2 and nitrates showed similar peak times during Eps. 3 and 4. Analysis of the episodes consistently showed that the long-lasting haze episodes were influenced by both the long-range transport of air pollutants from outside Seoul, mostly from China, and the accumulation of air pollutants that were locally emitted and transformed. [ABSTRACT FROM AUTHOR]

Since flood frequency increases with the impact of climate change, the damage that is emphasized on flood-risk maps is based on actual flooded area data; therefore, flood-susceptibility maps for the Seoul metropolitan area, for which random-forest and boosted-tree models are used in a geographic information system (GIS) environment, are created for this study. For the flood-susceptibility mapping, flooded-area, topography, geology, soil and land-use datasets were collected and entered into spatial datasets. From the spatial datasets, 12 factors were calculated and extracted as the input data for the models. The flooded area of 2010 was used to train the model, and the flooded area of 2011 was used for the validation. The importance of the factors of the flood-susceptibility maps was calculated and lastly, the maps were validated. As a result, the distance from the river, geology and digital elevation model showed a high importance among the factors. The random-forest model showed validation accuracies of 78.78% and 79.18% for the regression and classification algorithms, respectively, and boosted-tree model showed validation accuracies of 77.55% and 77.26% for the regression and classification algorithms, respectively. The flood-susceptibility maps provide meaningful information for decision-makers regarding the identification of priority areas for flood-mitigation management. [ABSTRACT FROM AUTHOR]

The heat island effect in cities becomes intensified due to rapid urbanization and industrialization. This urban heat island has negative effects such as increase in cooling energy use and impairment of urban air quality. This study aims to develop a predictive model for heat island in Seoul, Korea using neural networks. To create the neural network predictive model, air temperatures of 28 locations in Seoul for a year have been collected from automatic weather stations operated by the Korea Meteorological Administration. The neural network model was created and tested for estimating the urban heat island intensity according to albedo, building coverage, green area, building area, water area, road area, temperature, humidity, wind speed and direction, and precipitation. Finally, prediction results from the neural network model were compared with the measured data. The coefficients of correlation of the developed models range from 0.95 to 0.99. The analysis also indicates that the neural network model has better predictive performance compared to the multiple regression model. [ABSTRACT FROM AUTHOR]

ABSTRACT The Korea Meteorological Administration has limited understanding of how users interpret probabilistic forecast information and use it in their decision-making processes. Thus, a survey was conducted among users to find out at which probability threshold for adverse weather they would react and take protective action to minimize the losses. According to previous studies, probability threshold depends on the type of users but they are in general higher than a 50% forecasts chance of adverse weather, even though research has shown that the forecast value is maximized when actions are taken for probability of adverse weather lower than 50%. A collective value score model, defined as a weighted sum of user's satisfaction and threshold distribution in a group of users, is introduced as a measure of total satisfaction of a user group. The collective value score model is applied to a set of precipitation probabilistic forecasts of Seoul, South Korea during 2002-2011. The results show that the collective value score can be improved if the range of users' probability thresholds is widened rather than improving the forecast accuracy. [ABSTRACT FROM AUTHOR]

This paper aims to assess how occupants perceived their visual environments of diverse luminous ambiences created by daylight in apartment buildings. Daylighting can have a large influence on environmental condition to improve ambience, visual comfort, well-being and health of occupants. Thus, it is essential to understand what visual adaptive actions for the satisfaction of occupants and how they respond to given visual environments. A purpose-built living room with balcony extension was situated at Kyung Hee University in Korea (latitude 37.17N, longitude 127.01E) to monitor data throughout a 1-month period in winter. Thirty-two subjects participated and each subject spent a day in the test room. All subjects were given the opportunity to have artificial lighting and blinds control over the lighting ambience appropriate for their activity. Physical measurements such as illuminance levels of vertical and floor-planes, window luminance were monitored simultaneously which were cross-linked to the subjective assessment of blinds control. Experimental results revealed the factors affecting the occupant use of shading systems; visual comfort, seating orientation and blinds types could have an effect. The results of this study should provide useful information on daylighting as a function of photometrical and behavioural factors for future application in building design. [ABSTRACT FROM AUTHOR]

The number of social hymenoptera have decreased due to accelerated urbanization in Seoul, Korea, during the 1970s-1990s. However, recent changes in environmental conditions have brought distinct re-growth of their colonies. In this study, we analyzed the re-colonization trend of social hymenoptera in Seoul with moving-out reports submitted to 119 rescue services from 2000 to 2009. A total of 14 253 social hymenoptera findings and treatment cases were reported during that time, and the reported numbers increased continuously every year. Among them, 87% of the cases were related to social wasps and 13% were for honeybees. Social wasps peaked from July to September, when the colonies matured, whereas honeybees peaked from April to July when colonies divided. As observed by geographical information system ( GIS), moving-out cases formed hotspots in low-story buildings around green areas such as nearby forests or city green parks in Eunpyeong-gu and Gwanak-gu in Seoul. Among the social wasps, the most frequent species that caused a nuisance and direct stinging was Polistes rothneyi koreanus, the majority of which nested under eaves (63%). Among the honeybees, Apis mellifera was a nuisance while attaching to buildings and walls in the city (60%) during hive splitting. We present herein the situation of the return of social hymenoptera to Seoul and discuss the possible reasons for the recent increase in social wasps in urban areas, including enlarging the green space in urban areas and stable nesting places, which benefited colony development due to the relatively higher urban temperature and the few natural predators and parasitoids. [ABSTRACT FROM AUTHOR]

Creating comfortable indoor climates is one of fundamental functions of buildings and buildings use a large amount of energy to fulfill their function. Therefore, it is important to understand how and under what thermal environments, the occupants can achieve their comfort in their normal lives. This paper reports the results from a longitudinal field investigation, which has been conducted to reveal the comfort temperatures of occupants in open plan offices in summer, autumn and winter in Seoul, Korea and to identify the environmental factors that could affect comfort temperatures. The survey results confirm that comfort temperature would vary with seasons. This research provides the evidence to link the indoor and outdoor temperatures along with past thermal experience with comfort temperatures. An adaptive comfort model has been developed by this study for building occupants in Seoul, Korea based on the field investigation. Comparisons between the new adaptive comfort model and existing models have been also made. The establishment of an adaptive thermal comfort model for Seoul would have a significant impact on energy saving and for setting of thermal comfort standard for office buildings in Korea. [ABSTRACT FROM AUTHOR]

In 2009, a survey of 177 samples of fish and fishery products from the markets in Seoul was carried out to investigate total mercury and organic mercury (methylmercury) concentrations and to establish a correlation, if any, between total and organic mercury levels. Concentrations of total and organic mercury in canned tuna ranged 0.001–2.581 and 0.003–1.307 mg/kg, respectively; those for fish, such as cod or salmon, ranged 0.012–2.529 and 0.021–0.507 mg/kg, respectively. Ethylmercury was not detected. More than 50% of total mercury in the samples existed as organic mercury. The correlation coefficients (r 2) between total mercury and methylmercury concentrations of fish and fishery products found to have methylmercury were 0.844 and 0.976, respectively, which was statistically significant. There was a higher correlation in fishery products than in fish. Although there was no product in which mercury exceeded the standard set by the Food Code in 2008, with the exception of marlin steak, a processed food, which contained 1.307 mg/kg methylmercury. None exceeded the provisional tolerable weekly intake (PTWI) for mercury. Collectively, the results indicate that fish or fishery products marketed in Seoul, with the exception of marlin, have low levels of total or organic mercury and, thus, intake of these products is not a risk to public health. [ABSTRACT FROM PUBLISHER]

Background Candidemia is one of the fatal causes of nosocomial infection, requiring prompt recognition and treatment. Echinocandins are recommended for the treatment of invasive candidiasis and candidemia. Although similar clinical efficacy and safety are well known between caspofungin and micafungin, there are few studies comparing micafungin and anidulafungin. The objective of this study was to evaluate the clinical efficacy and safety between micafungin and anidulafungin treatment for adult patients with candidemia. Methods This retrospective cohort study was performed on adult candidemia patients diagnosed from January 2006 through December 2018 at a tertiary medical center, Seoul, South Korea. The study subjects included adult patients ≥19 years with candidemia who were only treated with micafungin or anidulafungin for more than 3 days. Baseline and clinical characteristics were reviewed through electrical medical records. Liver function was assessed according to Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0. Hepatotoxicity was defined as the elevation of more than CTCAE grade 1 and severe hepatotoxicity was defined as the CTCAE grade 3 or higher elevations. Results A total of 98 patients with candidemia was treated with micafungin (n = 46, 46.9%) or anidulafungin (n = 52, 53.1%). In the univariate analysis, there were no significant differences in age, sex, source of candidemia, and comorbidities between the micafungin and anidulafungin groups. Although the clearance time of candidemia after echinocandin treatment was shorter in the anidulafungin than in the micafungin (5.64 ± 2.79 vs. 8.06 ± 5.30 days, P = 0.009) group, there was no significant difference in terms of clinical response (51.9% vs. 46.7%), mycological response (76.9% vs. 67.4%), and mortality (54.3% vs. 55.8%) between these two groups. The overall incidence of hepatotoxicity was similar. Also, there was no difference in the development of hepatotoxicity or severe hepatotoxicity between micafungin and anidulafungin groups for patients with normal baseline liver function test(LFT) and abnormal baseline LFT. Conclusion Our results suggest that clinical efficacy and hepatotoxicity may be similar between micafungin and anidulafungin treatment for adult patients with candidemia. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]

This study focuses on the temporal variation in the compositional characteristics of atmospheric aerosols in Seoul, South Korea, during the consecutive high aerosol concentration episode from 30 December 2013 to 2 January 2014. The temporal variations in the observed physical, optical, and chemical properties show that there were three distinct episodes during the period: haze, mixed haze/Asian dust, and Asian dust episodes. For the haze period, the concentration of secondary inorganic aerosols increased and both secondary inorganic aerosols and calcium species exhibited simultaneously high concentrations during the mixed haze/Asian dust period. The neutralization factors by ammonia in the haze periods were higher as 1.03 than the other periods, meanwhile the neutralization contribution by calcium carbonate was relatively higher as 1.39 during the Asian dust episode. The backward trajectory analysis showed that concentrations of SO42−, NO3−, and NH4+ were relatively high when air masses moved over East China. Principal component analysis showed that water-soluble components originated from soil dust/incineration, secondary aerosols/biomass burning, and road dust from the haze aerosol. For the mixed haze/Asian dust episode, the major source of aerosols was estimated to have originated from soil dust, pollutants from fossil fuel combustion, biomass burning, and sea-salt emissions. Furthermore, the main sources of ionic species in the Asian dust aerosols were estimated to be sea-salt/soil dust, secondary aerosols/coal combustion, and road dust. [ABSTRACT FROM AUTHOR]

Background: Mild cognitive impairment (MCI) is an intermediate phase between normal aging and dementia. Since a majority of amnestic MCI (aMCI) cases progress to Alzheimer's disease (AD), it is considered the prodromal stage of AD and, therefore, a treatment target for the prevention of further cognitive decline. However, there is no approved treatment for MCI at present. Kami Guibi-tang (KGT) is a herbal drug used in Korean medicine to treat amnesia, insomnia, loss of appetite, and depression. We will explore the effectiveness and safety of KGT in amnestic MCI in this trial.Methods/design: The study will be a single-center, randomized, placebo-controlled, double-blind trial. Eligible participants diagnosed with amnestic MCI will be randomly allocated to a treatment or control group. Participants will take KGT or placebo granules, three times a day, for 24 weeks. The primary outcomes will be changes in Seoul Neuropsychological Screening Battery (SNSB) scores, and magnetic resonance imaging (MRI) measurements including those of brain metabolites, neurotransmitters, and cerebral blood flow. The secondary outcomes will include the safety assessment, measured by changes in blood chemistry, changes in blood protein and cholesterol levels related to AD pathology, and a comparison of MRI changes between the two groups, using age and genotype as covariates.Discussion: This study will be the first clinical trial to identify the therapeutic potential of Kami Guibi-tang for amnestic MCI. The findings will provide insight into the feasibility of large-scale trials to gather evidence for KGT as a treatment for MCI.Trial Registration: Korean Clinical Trial Registry, ID: KCT0002407 . Registered on 30 March 2017. [ABSTRACT FROM AUTHOR]

This study conducted an investigation on the damage by social wasps within the metropolis of Seoul and Busan of Korea. Damage by social wasps in Seoul has increased 5.5 times with total 12,406 cases in the past ten years. Damages were arisen from July to September the most at the outskirts of a city near mountains and continuously increased within the internal area of city. Social wasps turned out to inhabit open spaces such as eaves, window frame and garden among 49 nesting places and Polistes rothneyi koreanus were most frequently found of all species. As the final outcome, increase of green space within the urban area, stability of nesting place, city temperature, stability against natural enemy, influence of media are believed to be the reasons of increase of social wasps within the city. [ABSTRACT FROM AUTHOR]

Background: A biopsy of first recurrence or metastatic disease is recommended to re-evaluate oestrogen receptor status in patients with breast cancer and to select appropriate treatment. However, retesting for oestrogen receptor status with rebiopsy is not always feasible, depending on lesion location and the risk associated with biopsy, and in these cases clinicians continue to treat patients according to the oestrogen receptor status of the primary tumour. Consequently suboptimal therapy might be offered to these patients. We assessed the diagnostic accuracy and safety of 16α-[18F]fluoro-17β-oestradiol (18F-FES) PET-CT to assess oestrogen receptor status in patients with recurrent or metastatic breast cancer.Methods: We did a prospective cohort study at the Asan Medical Center, Seoul, South Korea. Eligible patients had breast cancer, with first recurrence or metastatic disease at presentation, were 19 years or older, and had an Eastern Cooperative Oncology Group performance status of 0-2. The primary objective was to show the agreement between qualitative 18F-FES PET-CT interpretation and the results of oestrogen receptor expression by immunohistochemical assay, a non-reference standard test. Whole-body 18F-FES PET-CT imaging was done after intravenous injection of 111-222 MBq of 18F-FES, with dosing primarily determined by radiation dosimetry analysis. 18F-FES uptake above background intensity was interpreted as positive. Efficacy was assessed in all patients with histologically confirmed recurrent or metastatic breast cancer who received 18F-FES and had PET-CT images available (intention-to-diagnose analysis), and safety was assessed in all patients who received 18F-FES. This study is registered with ClinicalTrials.gov, number NCT01986569.Findings: Between Nov 27, 2013, and Nov 10, 2016, 93 patients were enrolled. Of the 85 patients included in the efficacy analysis, 47 (55%) were oestrogen receptor-positive and 38 (45%) were oestrogen receptor-negative. Positive status percent agreement between the 18F-FES PET-CT results and oestrogen receptor status by immunohistochemical assay was 76·6% (95% CI 62·0-87·7) and the negative status percent agreement was 100·0% (90·8-100·0). Patients who were oestrogen receptor-positive and had a positive 18F-FES PET-CT result had a significantly higher progesterone receptor expression than those who were oestrogen receptor-positive and had a negative 18F-FES PET-CT result (23 [68%] of 34 patients vs 0 of 11 patients; p<0·0001). The most common adverse event was procedural pain in nine (10%) of 90 patients injected with 18F-FES. No adverse events were related to the study drug except injection site pain in one (1%) patient. No serious adverse events were recorded.Interpretation: The high negative percent agreement between 18F-FES PET-CT and oestrogen receptor status by immunohistochemical assay in this cohort suggests that positive 18F-FES uptake by recurrent or metastatic oestrogen receptor-positive breast cancer lesions could be an alternative to oestrogen receptor assays in this setting. Staging assessment should include 18F-FES PET-CT when retesting oestrogen receptor status is not feasible.Funding: Asan Institute for Life Sciences, Ministry of Health and Welfare, South Korea. [ABSTRACT FROM AUTHOR]

A vehicle fleet representative of passenger vehicles driven in the Seoul Metropolitan Region was investigated for primary emissions and secondary chemistry. Exhaust was photochemically oxidized in a flow reactor to determine the ammonium nitrate (NH 4 NO 3 ) aerosol formation potential from vehicles of gasoline, diesel and liquid petroleum gasoline (LPG) fuel types. Secondary formation of aerosol NH 4 NO 3 , was larger than primary emissions for all vehicle fuel types except diesel, for which negligible secondary NH 4 NO 3 production was observed. Although diesel vehicles emitted more primary nitrogen oxides than other vehicle types, ammonia emitted from gasoline and liquid petroleum gasoline fuels types limited the secondary production of NH 4 NO 3 . The results suggest that gasoline and liquid petroleum gasoline vehicles with three-way catalysts could be an important source of ammonia for NH 4 NO 3 aerosol formation in ammonia-limited environments, including the Seoul Metropolitan Region. [ABSTRACT FROM AUTHOR]