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Background: The endothelial glycocalyx (EG) is an important structure that regulates vascular homeostasis. Deep inferior epigastric perforator (DIEP) flap is expected to cause substantial EG breakdown owing to the long procedural duration and ischemia– reperfusion injury. This prospective, randomized, controlled study aimed to compare syndecan-1 levels during sevoflurane-remifentanil and propofol-remifentanil anesthesia in patients who underwent DIEP flap breast reconstruction.Methods: Fifty-one patients were randomized to either sevoflurane (n = 26) or propofol (n = 25) groups. Anesthesia was maintained with remifentanil in combination with either sevoflurane or propofol. The primary endpoint was the concentration of serum syndecan-1 measured at 1 h after surgery.Results: Fifty patients (98.0%) completed the study. Patients in the propofol group had significantly lower levels of syndecan-1 than patients in the sevoflurane group at 1 h after operation (23.8 ± 1.6 vs. 30.9 ± 1.7 ng/ml, respectively; Bonferroni corrected P = 0.012). There were no significant differences between groups in postoperative complications. The postoperative hospital stay was 8.4 ± 2.5 days in the sevoflurane group and 7.4 ± 1.0 days in the propofol group (P = 0.077).Conclusions: Propofol-remifentanil anesthesia resulted in lesser increases in syndecan-1 levels compared to increases with sevoflurane-remifentanil anesthesia in patients who underwent DIEP flap reconstruction. Our results suggest that propofol-remifentanil anesthesia shows protective effects against EG damage during DIEP flap breast reconstruction in contrast to sevoflurane-remifentanil anesthesia.

This study reports measurements of size-resolved aerosol composition at a site in Incheon along with other aerosol characteristics for contrast between Incheon (coastal) and Seoul (inland), South Korea, during a transboundary pollution event during the early part of an intensive sampling period between 4 and 11 March 2019. Anthropogenic emissions were dominant in the boundary layer over the study region between 4 and 6 March, with much smaller contributions from dust, smoke, and sea salt. The meteorology of this period (shallow boundary layer, enhanced humidity, and low temperature) promoted local heterogeneous formation of secondary inorganic and organic species, including high nitrate (NO3-) relative to sulfate (SO42-). Seoul exhibited higher PM2.5 levels than Incheon, likely due to local emissions. The following findings point to secondary aerosol formation and growth sensitivity to water vapor during this pollution event: (i) significant concentrations of individual inorganic and organic acids in the supermicrometer range relative to their full size range (∼40 %) at higher humidity; (ii) high correlation (r=0.95) between oxalate and SO42-, a marker of secondary aqueous production of oxalate; (iii) increased sulfur and nitrogen oxidation ratios as a function of humidity; and (iv) matching composition apportionment (for soluble ions) between the PM1 and PM2.5−1 size fractions. The last finding confirms that PM1 aerosol composition measurements fully capture PM2.5 composition apportionment (for soluble ions) during haze events and may therefore be reliably applied in modeling studies of such events over the full PM2.5 size range. However, the differences evident in the periods following the haze event imply that under other atmospheric conditions PM1 composition measurements will not fully reflect the apportionment of PM2.5 aerosols. The study period was marked by relatively low temperatures that made NO3- the most abundant species detected, pointing to the sensitivity of PM2.5 levels and composition as a function of season during such transboundary events. For instance, other such events in previous studies exhibited more comparable levels between SO42- and NO3- coincident with higher temperatures than the current study. This dataset can contribute to future evaluation of model PM2.5 composition to better support regulatory efforts to control PM2.5 precursors.

Nipple-areolar complex (NAC)-related complications are common during nipple-sparing mastectomy (NSM), with obesity as a risk factor. Although the incidence of NAC-related complications after robotic NSM (RNSM) with immediate breast reconstruction (IBR) is lower than that after conventional NSM, it remains one of the most unwanted complications. We aimed to evaluate body composition-based risk factors for NAC-related complications after RNSM with IBR. Data of 92 patients with breast cancer who underwent RNSM with IBR using direct-to-implant or tissue expander from November 2017 to September 2020 were analyzed retrospectively. Risk factors for NAC-related complications were identified with a focus on body composition using preoperative transverse computed tomography at the third lumbar vertebra level. Postoperative complications were assessed for 6 months. The most common complication was NAC ischemia, occurring in 15 patients (16%). Multivariate analysis revealed a low skeletal muscle index/total adipose tissue index (SMI/TATI) ratio as an independent NAC ischemia risk factor. An increase in the SMI/TATI ratio by one decreased the incidence of NAC ischemia by 0.940-fold (p = 0.030). A low SMI/TATI ratio is a risk factor for postoperative NAC ischemia in patients undergoing RNSM with IBR for breast cancer. Preoperative body composition-focused evaluation is more valuable than simple body mass index assessment.

Intraoperative hemodynamics can affect postoperative kidney function. We aimed to investigate the effect of intraoperative mean arterial pressure (MAP) as well as other risk factors on the occurrence of acute kidney injury (AKI) after robot-assisted laparoscopic prostatectomy (RALP). We retrospectively evaluated the medical records of 750 patients who underwent RALP. The average real variability (ARV)-MAP, standard deviation (SD)-MAP, time-weighted average (TWA)-MAP, area under threshold (AUT)-65 mmHg, and area above threshold (AAT)-120 mmHg were calculated using MAPs collected within a 10-s interval. Eighteen (2.4%) patients developed postoperative AKI. There were some univariable associations between TWA-MAP, AUT-65 mmHg, and AKI occurrence; however, multivariable analysis found no association. Alternatively, American Society of Anesthesiologists physical status ≥ III and the low intraoperative urine output were independently associated with AKI occurrence. Moreover, none of the five MAP parameters could predict postoperative AKI, with the area under the receiver operating characteristic curve values for ARV-MAP, SD-MAP, TWA-MAP, AUT-65 mmHg, and AAT-120 mmHg being 0.561 (95% confidence interval [CI], 0.424–0.697), 0.561 (95% CI, 0.417–0.704), 0.584 (95% CI, 0.458–0.709), 0.590 (95% CI, 0.462–0.718), and 0.626 (95% CI, 0.499–0.753), respectively. Therefore, intraoperative MAP changes may not be a determining factor for AKI after RALP.

Background Mammography yields inevitable recall for indeterminate findings that need to be confirmed with additional views. Purpose To explore whether the artificial intelligence (AI) algorithm for mammography can reduce false-positive recall in patients who undergo the spot compression view. Material and Methods From January to December 2017, 236 breasts from 225 women who underwent the spot compression view due to focal asymmetry, mass, or architectural distortion on standard digital mammography were included. Three readers who were blinded to the study purpose, patient information, previous mammograms, following spot compression views, and any clinical or pathologic reports retrospectively reviewed 236 standard mammograms and determined the necessity of patient recall and the probability of malignancy per breast, first without and then with AI assistance. The performances of AI and the readers were evaluated with the recall rate, area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and accuracy. Results Among 236 examinations, 8 (3.4%) were cancers and 228 (96.6%) were benign. The recall rates of all three readers significantly decreased with AI assistance ( P Conclusion AI assistance significantly reduced false-positive recall without compromising cancer detection in women with focal asymmetry, mass, or architectural distortion on standard digital mammography regardless of mammographic breast density.

This study aimed to investigate whether parity is associated with the prevalence of low muscle mass in postmenopausal women.This study was performed using data from the 2010-2011 Korean National Health and Nutrition Examination Survey, which included 1,338 postmenopausal women aged 46 to 70 years. The association between parity and low muscle mass was analyzed after adjusting parity, multiparity, age, body mass index, diabetes mellitus, education level, and Homeostatic Model Assessment of Insulin Resistance and using weighted multiple logistic regression analysis. Modifiable risk factors were evaluated in a susceptible population. Low muscle mass was defined as an appendicular skeletal muscle mass index below 2 SDs with a cutoff value of 5.45 kg/m 2 .The low muscle mass group ( n = 343) had lower parity, lower body mass index, more frequent previous history of diabetes mellitus, higher Homeostatic Model Assessment of Insulin Resistance, and higher education level compared with the non-low muscle mass group ( n = 995). After adjusting for the confounding factors, parity with three births or more was associated with a significantly lower odds of postmenopausal low muscle mass than nulliparity (model 1: odds ratio, 0.32; 95% confidence interval, 0.12-0.87; P = 0.03; model 2: odds ratio, 0.27; 95% confidence interval, 0.11-0.67; P0.05). In the subgroup analysis of the lower parity group, moderate aerobic activity was associated with a lower low muscle mass prevalence.A lower parity is associated with increasing the odds of low muscle mass in postmenopausal Korean women. Moderate aerobic activity may be effective in lowering the odds of low muscle mass in postmenopausal women with lower parity.

We aimed to investigate the relationship between intraoperative mean arterial pressure (MAP) and acute kidney injury (AKI) occurrence after robot-assisted laparoscopic prostatectomy (RALP), as well as the relationship between MAP and the maximal increase in serum creatinine (SCr) levels. We retrospectively evaluated the medical records of 750 patients who underwent RALP. The average real variability (ARV)-MAP, standard deviation (SD)-MAP, time-weighted average (TWA)-MAP, area under threshold (AUT)-65 mmHg, and area above threshold (AAT)-120 mmHg were calculated using MAPs collected within a 10-s interval. Eighteen (2.4%) patients developed postoperative AKI. None of the five MAP parameters could predict postoperative AKI, with the area under the receiver operating characteristic curve values for ARV-MAP, SD-MAP, TWA-MAP, AUT-65 mmHg, and AAT-120 mmHg being 0.561 (95% confidence interval [CI], 0.424–0.697), 0.561 (95% CI, 0.417–0.704), 0.584 (95% CI, 0.458–0.709), 0.590 (95% CI, 0.462–0.718), and 0.626 (95% CI, 0.499–0.753), respectively. ARV-MAP (per 15-mmHg/min increase) and TWA-MAP (per 30-mmHg increase) were positively correlated with delta-SCr levels (β = 0.21, P = 0.010 and β = 0.14, P = 0.002; respectively). However, the resulting increases did not cause AKI. Therefore, intraoperative MAP changes may not be a determining factor for AKI after RALP.

Seven nitrosamines and three nitramines in particulate matter with an aerodynamic diameter of less than or equal to 2.5 μm (PM2.5) collected in 2018 in Seoul, South Korea, were quantified. Annual mean concentrations of the sum of nitrosamines and nitramines were 9.81 ± 18.51 and 1.12 ± 0.70 ng/m3, respectively, and nitrosodi-methylamine (NDMA) and dimethyl-nitramine (DMN) comprised the largest portion of nitrosamines and nitramines, respectively. Statistical analyses such as non-parametric correlation analysis, positive matrix factorization, analysis of covariance, and orthogonal partial least squared discrimination analysis were carried out to identify contribution of the atmospheric reactions in producing NDMA and DMN. In addition, kinetic calculation using reaction information obtained from the previous chamber studies was performed to estimate concentrations of NDMA and DMN that might be produced from the atmospheric reactions. It was concluded that (1) the atmospheric reactions contributed to the concentrations of NDMA more than they did for those of DMN, (2) the contribution of atmospheric reactions to the concentrations of NDMA and DMN was significant due to high NO2 concentrations in winter, and (3) primary emissions predominantly affected the ambient concentrations of NDMA and DMN in spring, summer, and autumn.

대기 중 수증기는 미세먼지의 흡습 성장을 야기하고, 입자상 물질의 측정에 있어 오차를 수반한다. 본 연구에서는 미세먼지 측정기 내부의 습기가 측정 결과에 미치는 영향에 대해 분석하였다. 1년간 연속으로 측정된 외기습도, 측정기기 상대습도, PM2.5 및 광산란계수를 관찰했다. 기기 상대습도가 저습으로 유지되는 기간과 그렇지 않은 기간 동안 광산란계수 ≤ 200 Mm-1와 PM2.5 ≤ 90 ㎍/m³에서 질량산란효율을 계산했고, 저습일 때 PM2.5와 광산란계수의 상관성이 높게 나타났다. 연간 대기 절대습도를 이용해 실제 습기량이 측정에 미치는 영향을 분석했다. 겨울철과 여름철의 외기절대습도 평균은 각각 0.34%와 1.84%로 기기 상대습도가 50%에 도달하는 시간은 약 668일과 46일로 예측되었다. 결론적으로 본 연구를 통하여 외기절대습도에 따른 기기 상대습도의 시간에 대한 변화를 선형 회귀분석해 확산건조기의 수명을 예측할 수 있다.

Despite frequent observations of high particulate matter (PM) concentrations in Seoul, Korea, the sulfate (SO42−) concentrations in PM with an aerodynamic diameter below or equal to 2.5 μm (PM2.5) in Seoul have been reduced during the 1990s. However, there has been no decreasing trend during the 2000s. Despite the very low ambient SO2 concentrations, high SO42− concentration episodes frequently occur in Seoul; however, the reasons for this remain poorly understood. In the present study, we sought to determine the major factors that enhance sulfur oxidation in Seoul by analyzing measurement data from an intensive air quality monitoring station in the Seoul metropolitan area acquired in 2015. Additionally, we aimed to distinguish the contributions of local sources and long-range transport to the elevated SO42− concentrations in PM2.5 in Seoul. In some cases in March and October 2015, the molar ratio of SO42− to SO2, which reflects sulfur partitioning between the particle and gas phases, showed an exponential increase with an increase of relative humidity (RH). However, despite the fact that the RH was high during August 2015, no statistically significant relationship was observed between RH and the molar ratio of SO42− to SO2 during this month. In August 2015, the molar ratio of SO42− to SO2 showed an exponential increase with increasing O3 concentration. Therefore, under sufficient RH, the concentrations of radical oxidants might be the most important factor that underlies the increase in ambient SO42− concentrations. No significant relationship was observed between the molar ratio of SO42− to SO2 and O3 in October. Furthermore, using Potential Source Density Function (PSDF) and backward trajectory analysis, the high SO42− concentrations in March 2015 were found to be caused by the transportation of air pollutants from China and local sources around Seoul. The high SO42− concentrations in August 2015 are concluded to have been greatly affected by these power plant emissions in the Taean area on the west coast of Korea. The high SO42− concentrations in October 2015 appear to have been caused by the transportation of air pollutants from North Korea. In summary, the high SO42− concentration in Seoul is affected by long-range transport from China and by the emissions from around the Seoul metropolitan area, such as Taean or North Korea.

We aimed to investigate the optimal radiologic method to determine Milan criteria (MC) for the prediction of recurrence in patients who underwent locoregional treatment (LRT) for hepatocellular carcinoma (HCC) and subsequent liver transplantation (LT).This retrospective study included 121 HCC patients who underwent LRT and had both liver dynamic CT and MRI. They were classified with MC using four cross combinations of two imaging modalities (CT and MRI) and two diagnostic criteria (modified Response Evaluation Criteria in Solid Tumors [mRECIST] and Liver Imaging Reporting and Data System treatment response algorithm [LI-RADS TRA]). Competing risk regression was performed to analyze the time to recurrence after LT. The predictive abilities of the four methods for recurrence were evaluated using the time-dependent area under the curve (AUC).Competing risk regression analyses found that beyond MC determined by MRI with mRECIST was independently associated with recurrence (hazard ratio, 6.926; p = 0.001). With mRECIST, MRI showed significantly higher AUCs than CT at 3 years and 5 years after LT (0.597 vs. 0.756, p = 0.012 at 3 years; and 0.588 vs. 0.733, p = 0.024 at 5 years). Using the pathologic reference standard, MRI with LI-RADS TRA showed higher sensitivity (61.5%) than CT with LI-RADS TRA (30.8%, p0.001) or MRI with mRECIST (38.5%, p0.001).MRI with mRECIST was the optimal radiologic method to determine MC for the prediction of post-LT recurrence in HCC patients with prior LRT.• MRI with modified RECIST (mRECIST) is the optimal preoperative method to determine Milan criteria for the prediction of post-transplant HCC recurrence in patients with prior locoregional treatment. • With mRECIST, MRI was better than CT for the prediction of post-transplant recurrence.

The purpose of this study was to assess the effect of alcohol consumption on metabolic syndrome (MetS) and obesity in Koreans by analysis of big data from the National Health Insurance Service health checkup database. A total of 26,991,429 subjects aged 20 years or older were included. Alcohol consumption was divided into five groups: nondrinkers, ≤7.0 g/d, 7.1–14.0 g/d, 14.1–28.0 g/d, ≥28.1 g/d. Logistic regression analyses were performed after adjusting for age, exercise, smoking, and income. The odds ratios (ORs) of MetS and obesity in men and women were lowest at ≤7.0 g/d, similar to that of the nondrinkers at 7.1–14.0 g/d, and increased with the alcohol consumption. At 7.1–14.0 g/d in older men, the ORs of metabolic syndrome and obesity were similar to those in the nondrinkers, but the OR of obesity was slightly increased in older women. This study suggests that the risk of MetS and obesity may be higher in Korean men, women, and the elderly who drink more than 14 g/d than the nondrinkers. In people with obesity or abdominal obesity, or those who need to manage their blood pressure, glucose, or triglyceride, drinking more than 7 g/d may increase the risk of MetS.

Countries in Northeast Asia have been regulating PM

Postoperative bowel dysfunction poses difficulty to patients during their recovery from surgery, and reversal agents may affect bowel function. This study aimed to investigate and compare the effects of sugammadex and a neostigmine/glycopyrrolate combination on postoperative bowel movement in patients undergoing robotic thyroidectomy. The electronic medical records of 122 patients, who underwent robotic thyroidectomy between March 2018 and December 2020, were retrospectively reviewed. Demographic, clinical, and laboratory findings and the first gas-passing time after surgery were assessed. The number of patients with a first gas emission time over 24 h was significantly higher in the neostigmine group than in the sugammadex group (p = 0.008). Multivariate logistic regression analysis indicated that sugammadex was a prognostic factor for the first gas-passing time within 24 h (odds ratio = 4.60, 95% confidence interval 1.47–14.36, p = 0.005). Although postoperative bowel motility, based on the first gas emission time, was comparable, the number of patients with a first gas emission time within 24 h was significantly higher in the sugammadex group than in the neostigmine group. This shows that the use of sugammadex did not affect the delayed recovery of postoperative bowel motility after robotic thyroidectomy.

Chemical effects on the size-resolved hygroscopicity of urban aerosols were examined based on the Korea–US Air Quality Study (KORUS-AQ, 2020) field campaign data. The information on size-resolved hygroscopicity and the chemical composition of aerosols were obtained by a hygroscopic tandem differential mobility analyzer (HTDMA) and a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), respectively. Good correspondence was shown between measured and estimated κ values calculated from the combination of bulk chemical composition data and oxidation parameters of organic aerosols (f44 and O∕C). These results imply that chemical composition is closely associated with aerosol hygroscopicity. However, the correlation between measured and estimated κ values degraded as particle size decreased, implying that size-resolved chemical composition data are required for more detailed hygroscopicity analysis. In addition to size-resolved chemical data, the m∕z tracer method was applied for size-resolved organic factors. Specifically, m∕z 57 and 44 were used as AMS spectral markers for hydrocarbon-like organic aerosol (HOA) and oxygenated organic aerosol (OOA), respectively. These size-resolved chemical composition data were found to be critical in explaining size-dependent hygroscopicity, as well as the diurnal variation in κ for small particles, i.e., low κ in the morning and high κ in the afternoon. Additionally, aerosol mixing state information was associated with the size-resolved chemical composition data. That is to say that the relationship between the number fraction of each hygroscopicity mode and the volume fraction of different chemical composition was investigated. For example, the HOA volume fraction comprised about 60 % of the variation in less hygroscopic (LH) mode number fractions for externally mixed aerosols.

Objective To investigate the three-dimensional (3D) surgical accuracy between virtually planned and actual surgical movements (SM) of the maxilla in two-jaw orthognathic surgery. Methods The sample consisted of 15 skeletal Class III patients who underwent two-jaw orthognathic surgery performed by a single surgeon using a virtual surgical simulation (VSS) software. The 3D cone-beam computed tomography (CBCT) images were obtained before (T0) and after surgery (T1). After merging the dental cast image onto the T0 CBCT image, VSS was performed. SM were classified into midline correction (anterior and posterior), advancement, setback, anterior elongation, and impaction (total and posterior). The landmarks were the midpoint between the central incisors, the mesiobuccal cusp tip (MBCT) of both first molars, and the midpoint of the two MBCTs. The amount and direction of SM by VSS and actual surgery were measured using 3D coordinates of the landmarks. Discrepancies less than 1 mm between VSS and T1 landmarks indicated a precise outcome. The surgical achievement percentage (SAP, [amount of movement in actual surgery/amount of movement in VSS] × 100) (%) and precision percentage (PP, [number of patients with precise outcome/number of total patients] × 100) (%) were compared among SM types using Fisher’s exact and Kruskal–Wallis tests. Results Overall mean discrepancy between VSS and actual surgery, SAP, and PP were 0.13 mm, 89.9%, and 68.3%, respectively. There was no significant difference in the SAP and PP values among the seven SM types (all p > 0.05). Conclusions VSS could be considered as an effective tool for increasing surgical accuracy.

Contrast-induced acute kidney injury (CI-AKI) is one of the leading causes of new-onset renal failure in hospitalized patients. Statin has been evaluated for its protective effect against CI-AKI but rarely in patients receiving intravenous (IV) administrations of iodine-based contrast media for enhanced computed tomography (CT). In total, 12,371 patients who underwent contrast-enhanced abdominopelvic CT were retrospectively reviewed and stratified into statin users and statin nonusers. Subgroup analyses comparing high-intensity statins with low- to moderate-intensity statins were conducted within statin users and similar comparisons were performed within statin users stratified based on baseline eGFR. Overall, CI-AKI events did not occur less in statin users compared with non-statin users (p = 0.342). Within statin users, CI-AKI events did not decrease in high-intensity statin users compared with low- to moderate-intensity statin users (p = 0.355). Moreover, no significant difference in CI-AKI events was found between high-intensity statin users and low- to moderate-intensity statin users even after stratifying the patients with baseline eGFR. Collectively, statin was not significantly associated with the risk of CI-AKI events in patients undergoing contrast-enhanced abdominopelvic CT and high-intensity statins did not show significant association with CI-AKI over low- to moderate-intensity statins in the subgroup analysis. • Statin is not associated with risk of CI-AKI events in patients undergoing intravenous administration of contrast-enhanced CT. • CI-AKI incidence among high-intensity statin users was not significantly different from that of low- to moderate-intensity statin users.

Background: Long-term antiviral therapy (AVT) for chronic hepatitis B (CHB) reduces the risk of hepatocellular carcinoma (HCC). We assessed the temporal trends in the incidence of HCC over time during long-term AVT among Asian patients with CHB. Methods: Patients with CHB receiving entecavir/tenofovir (ETV/TDF) as a first-line antiviral were recruited from four academic hospitals in the Republic of Korea. We compared the incidence of HCC during and after the first 5 years of ETV/TDF treatment. Results: Among 3,156 patients, the median age was 49.6 years and males predominated (62.4%). During the follow-up, 9.0% developed HCC. The annual incidence of HCC per 100 person-years during the first 5 years (n = 1,671) and after the first 5 years (n = 1,485) was statistically similar (1.93% vs. 2.27%, P = 0.347). When the study population was stratified according to HCC prediction model, that is, modified PAGE-B score, the annual incidence of HCC was 0.11% versus 0.39% in the low-risk group ( 0.05). A Poisson regression analysis indicated that the duration of AVT did not significantly affect the overall trend of the incidence of HCC (adjusted annual incidence rate ratio = 0.85; 95% confidence interval, 0.66–1.11; P = 0.232). Conclusions: Despite long-term AVT, the risk of HCC steadily persists over time among patients with CHB in the Republic of Korea, in whom HBV genotype C2 predominates. Impact: Careful HCC surveillance is still essential.