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Interfacial reactions between the electric arc furnace (EAF) slag, i.e., CaO–SiO2–FeO–MgO–Al2O3–MnO system, and the magnesia refractory as a function of direct reduced iron (DRI) addition (0, 10, 20, 30 wt%) were investigated at 1550 °C under an Ar atmosphere. MgO solubility increases with increasing DRI content by decreasing basicity (i.e., CaO/SiO2 ratio), which is due to an increase in SiO2 supplied from DRI. The measured MgO content was always lower than the theoretical MgO saturation level irrespective of DRI content because the magnesiowustite (MW) intermediate layer, which formed at the slag/refractory interface, retarded the direct dissolution of the refractory by acting as a self-protective layer. The thickness of the MW intermediate layer and dissolution depth were proportional to DRI content. However, the penetrativity decreased with increasing DRI content by decreasing the fluidity of the slag. Several kinetic parameters were estimated, including the dissolution rate constant of the MW intermediate layer, the dissolution rate of the MgO refractory, and the rate constant of MW growth. Dissolution of MgO refractory is controlled by the dissolution of the MW intermediate layer. Increasing the growth rate is very important for protecting refractory after the formation of a MW intermediate layer. In addition, we provided a schematic diagram of the slag/refractory interfacial reaction phenomena that compares situations of low and high DRI content. The results of the present study show that it is necessary to control DRI content to minimize refractory degradation during the EAF process. If a large amount of DRI must be used in the EAF process, then MgO content in the slag should be at the saturation limit at first, which accelerates growth of the MW intermediate layer.

Background and Objectives This work investigates the clinical characteristics of benign paroxysmal positional vertigo (BPPV) according to etiology by comparing idiopathic BPPV (iBPPV), BPPV occurring after head trauma (tBPPV) and BPPV associated with idiopathic sudden sensory neural hearing loss (sBPPV).Subjects and Method A total of 869 patients who were diagnosed and treated for BPPV were reviewed retrospectively. Patients were divided into three groups according to the probable etiology of BPPV: iBPPV vs. tBPPV vs. sBPPV. We investigated and compared demographics, the affected sides and canals, the number of canalith repositioning procedure (CRP) performed to achieve successful reposition, canal conversion and recurrence among the three groups. Among the three groups, BPPV patients who performed caloric test and/or video head impulse test (vHIT) were additionally evaluated and compared.Results The iBPPV group (n=787) had greater female preponderance (72%, 567/787) than the tBPPV (n=51) and sBPPV groups (n=31, p

Background/Aim: This study aimed to investigate the process of homeostatic restoration in the tracheal mucosa (TM) after thyroid surgery. Materials and Methods: Fifty-four rats were divided into normal controls (NC) and three experimental groups: (i) flap elevation (FE), (ii) thyroid exposure (TE), and (iii) thyroid isthmusectomy (TI). Expression of mRNA and proteins of key factors regulating homeostasis were evaluated in the TM obtained 3, 7, and 21 days after thyroid surgery. Results: Increased mRNA expression of transforming growth factor-β1 (TGF-β1), hypoxia-inducible factor-1α (HIF-1α), and matrix metalloproteinase-9 (MMP-9) were observed 21 days after thyroid surgery in all experimental groups compared to that of NC group. Conclusion: Thyroid surgery leads to an actual increase of TGF-β1, HIF-1α, and MMP-9 expression in the TM. This increased expression of key regulators of homeostatic restoration in the TM lasts for a considerable period of time after surgery, especially if the extent of surgery increased.

The influence of slag composition of FeO/TiO2 (=F/T) ratio, Al2O3/(SiO2+Al2O3) (=A/(S+A)) ratio and oxygen partial pressure ( p O 2 = 10 − 10 t o 10 − 9 a t m ) on the thermodynamic behavior of vanadium oxide in molten ilmenite smelting slag, i.e., FetO-TiO2-MgO-Al2O3-SiO2 system, was investigated at 1550 °C. The distribution ratio of vanadium (= L V ) between molten iron and FetO-TiO2-MgO-Al2O3-SiO2 slag increases with increasing F/T ratio, while it decreases with increasing A/(S+A) ratio. In addition, l o g L V generally increases with increasing theoretical optical basicity of the slag (= Λ s l a g ). Vanadium oxide (VOx) is expected to behave as an acidic component in the present system. Vanadium in ilmenite smelting slags primarily consist of V3+, V4+, and V5+ ions, as determined by Gaussian deconvolution of X-ray photoelectron spectra. A linear relationship between l o g ( w t % V 4 + / w t % V 3 + ) and l o g p O 2 is confirmed. Both (wt% V3+) and (wt% V5+) ions increase with increasing F/T ratio, whereas (wt% V4+) ions show the opposite behavior with increasing F/T ratio, irrespective of A/(S+A) ratio. Meanwhile, (wt% V3+) increase while (wt% V4+) and (wt% V5+) decrease with increasing A/(S+A) ratio. The linear relationship between l o g ( w t % V 3 + / w t % V 5 + ) and l o g ( w t % V 4 + ) has a slope of 1.8, which is good agreement with the theoretical slope of 2.0, which indicates that multi-valent vanadium ion species, i.e., V3+, V4+, and V5+, are thermodynamically balanced based on redox equilibria.

Fluorspar (CaF2) is commonly used to control the fluidity of slag in ladle-refining of steel. However, because it is desirable to reduce CaF2 consumption because of its environmental impacts, the industrial waste material such as white mud (WM) was investigated as a potential substitute for fluorspar. Steel sample (Fe-0.3C-0.9Mn-0.3Si-0.03Al-0.05S, mass pct) was melted in a high-frequency induction furnace, followed by additions of ladle slag (CaO-Al2O3-SiO2-5MgO-xCaF2, CaO/Al2O3=3, x = 0 to 10 mass pct) and fluxing agent (WM) at 1823 K (1550 °C). The desulfurization experiments were carried out by reducing CaF2 content in the ladle slag and increasing the addition of WM. Ladle slag with added WM showed an overall mass transfer coefficient of sulfur (k O) equivalent to or higher than that of conventional 10 mass pct CaF2-containing ladle slag. In a slag melting experiment based on DIN 51730 standard, the melting rate of mixed slag increased with the amount of WM added, which is considered to have a positive effect on the initial desulfurization rate. In addition, adding WM provided sulfide capacity of the slag equivalent to that of CaF2-containing slag. Consequently, the use of WM yielded slag having $$k_{{\text{O}}}$$ k O equivalent to or higher than that of conventional ladle slag with 10 pct CaF2, and thus, WM shows promise as a partial replacement for fluorspar.

The effect of slag composition under M’O (monoxide, M = Fe,Mg) saturation and fully liquid conditions on dephosphorization and slag foamability was evaluated in an electric arc furnace (EAF) steelmaking plant operation by considering thermodynamics and phase equilibria. It was confirmed that M’O saturation slag is more favorable for higher dephosphorization than fully liquid slag due to its high activity of CaO as a thermodynamic driving force. As a quantitative measure of slag foamability, the foaming index was clearly dependent on the temperature and slag composition. Moreover, foam stability was evaluated by applying the predominance stability diagram based on phase equilibria. Consequently, it can be suggested that an efficient direction for dephosphorization and slag foaming during the EAF process is to generate high CaO activity as well as small amounts of M’O monoxide and dicalcium silicate (Ca2SiO4) compounds.

Laboratory experiment and thermodynamic calculation for the Ti-containing 24 mass pct Cr ferritic stainless steel with a CaO-SiO2-Al2O3-MgO system slag were performed to investigate the effect of slag addition on the inclusion characteristics in molten steel. The morphology, composition, and size evolution of inclusions in steel samples were analyzed in three-dimensional by the electrolytic extraction method and in two-dimensional by the automatic analysis method. The results showed that the Ti content significantly decreased after the slag addition. However, the change of the Si content showed an opposite tendency. The decrease of the Ti content in steel was due to the reduction of SiO2 and Al2O3 in the slag by dissolved Ti in steel. An increase of the TiO2 content in the slag can decrease the Ti loss in steel based on the slag-steel kinetic analysis. The total O content in the steel melt decreased from 62 to 26 ppm, and the steel cleanliness was improved, since the number density of inclusions decreased after the slag refining. The results of a kinetic analysis showed that the rate-determining step of the oxidation of Ti in the steel and the reduction of SiO2 in the slag were the mass transfer on the slag side. In addition, high Ti2O3-containing inclusions were found to be transformed to Cr2O3-Ti2O3-Al2O3 and Cr2O3-Ti2O3-SiO2 system inclusions after the slag addition. The Al2O3 contents in inclusions increased while the Ti2O3 contents decreased with time. However, there were some amount of high melting point inclusions with high Al2O3 content, which were not what we expected. When plotted on logarcxithmic scales, the mole ratio $$X_{{{\text{Al}}_{2} {\text{O}}_{3} }} /(X_{{{\text{Ti}}_2 {\text{O}}_{3} }} \cdot X_{{{\text{Cr}}_{2} {\text{O}}_{3} }} )$$ X Al 2 O 3 / ( X Ti 2 O 3 · X Cr 2 O 3 ) values of the inclusions were expressed as a linear function of the $$a_{\text{Al}}^{2} /(a_{Ti}^{2} \cdot a_{\text{Cr}}^{2} \cdot a_{\text{O}}^{3} )$$ a Al 2 / ( a Ti 2 · a Cr 2 · a O 3 ) values of the steel melts with a slope of unity, which was theoretically expected.

The effect of industrial waste flux addition on dephosphorization of molten steel and refractory corrosion(-protection) by electric arc furnace (EAF) slag using direct reduced iron (DRI) at 1823 K (1550 °C) was investigated. The activity of CaO and FeO is the thermodynamic driving force for dephosphorization, but it decreased with the use of DRI due to increased SiO2 content in the slag. Industrial waste fluxes were added to the slag to minimize refractory corrosion and improve dephosphorization efficiency. Red mud (RM) and white mud (WM), which are generated in the process of manufacturing aluminum hydroxide from bauxite using the Bayer process, were used as fluxing materials. The RM and WM mainly consist of Fe2O3 and CaO, respectively, and these positively affect the dephosphorization. Dephosphorization efficiency increased as industrial waste fluxes addition increased (3 to 7 mass pct). At the same time, the effect of industrial waste fluxes on the refractory corrosion-protection behavior was confirmed by considering the change in thickness of the magnesiowustite (MW) layer that formed at the interface between the ‘FeO-rich’ EAF slag and the magnesia refractory. Experimental results confirmed that 3 to 4 mass pct WM addition in the slag can compensate for the dephosphorization efficiency while minimizing the refractory corrosion in the EAF process using 20 pct DRI as an alternative iron source.

It is unknown whether persistent metabolic syndrome (MetS) is associated with an increased risk of cholangiocarcinoma (CCA). Therefore, we investigated the risk of CCA according to changes in MetS status.This nationwide cohort study included 8,581,407 adults who underwent anthropometric measurements and laboratory tests in two consecutive national health screenings during 2009-2012 and observed the subjects until 2017. Individuals with cancer, or follow-up duration1 year were excluded (n = 377,915). Subjects were classified into the MetS-free, MetS-developed, MetS-improved, and MetS-persistent groups. The outcome was the incidence of CCA, identified using the claims database. Multivariable Cox proportional hazards regression models were used.Among the 8,203,492 subjects (mean age 48.9 ± 12.8 years; 56.7% male), 7506 CCA patients were newly identified during a median follow-up of 5.1 years. The probability of CCA was consistently higher in the MetS-persistent group than in the MetS-free group (P 0.001). MetS-persistent status was significantly associated with an increased risk of CCA compared with the MetS-free status (unadjusted hazard ratio [HR] 2.8, 95% confidence interval [CI] 2.66-2.95), even after adjusting for multiple covariates (adjusted HR 1.07, 95% CI 1.01-1.13). Improved or newly developed MetS was not associated with CCA risk in the fully adjusted model (aHR 1.02, 95% CI 0.94-1.10 and aHR 0.99, 95% CI 0.92-1.06, respectively).MetS was associated with an increased risk of CCA if it persisted for ≥2 years. Our finding suggests that MetS may be a potentially modifiable risk factor for CCA.

Omega-3 fatty acids have been shown to be effective in lowering triglyceride (TG) levels; however, tolerability issues arise due to the large size of the pills. The purpose of this study was to examine the safety, compliance, and efficacy of Omethyl QTlet soft capsules (OQCs). This multi-center, prospective, observational study evaluated the safety, compliance, and efficacy of OQCs. Patients with hypertriglyceridemia with a history of omega-3 fatty acid intake were enrolled in this study and were prescribed OQCs (2 g–4 g/day) for eight weeks. All adverse events (AEs), adverse drug reactions (ADRs), and serious adverse events (SAEs) were recorded for safety evaluation. Adherence to treatment was assessed using questionnaires, and efficacy was assessed by changes in lipid and lipoprotein levels after eight weeks from baseline. The convenience of taking medication was analyzed for 580 patients, and the efficacy test was performed for 563 patients. The AE and ADR rates were 8.2% and 5.7%, respectively. There were only two SAEs. Of the patients, 55.8% responded that the OQC improved medication convenience, and mean changes in TG, total cholesterol, LDL-C, and non-HDL-C from baseline to eight weeks were −37.88 mg/dL, −11.56 mg/dL, −5.55 mg/dL, and −10.87 mg/dL, respectively (p-values < 0.001). In patients who had previously taken omega-3 fatty acids, OQCs showed safety and efficacy in lowering TG, and it was confirmed that compliance with medicine also improved compared to omega-3 fatty acids.

Background: With the consistent increase in life-expectancy, excavating novel sources of regenerative medicine is an important objective to enhance disease free life expectancy. A comprehensive protocol for using human endometrium derived induced pluripotent stem cells to derive hematopoietic and erythroid lineages will be elaborated, through a two-phase culture system. Method: Discarded endometrial tissues were obtained from women receiving hysterectomy in their 4th to 5th decade due to benign uterine conditions. The endometrial cells isolated were expanded to passage 3-4 to allow stromal cells to dominate in the culture environment. pCE-Sox2, Oct4, Klf4, L-Myc and Lin28 episomal vectors were used to electrotransfection the endometrial stromal cells. The erythroblast differentiation of these established induced pluripotent stem cells (iPSCs) were conducted in two phases. The first 8 days involves commitment to hematopoietic stem cells through embryoid body with robust expansion on murine bone marrow stromal cells. The second phase involves feeder free conditions with hydrocortisone, stem cell factor, interleukin-3, and recombinant EPO. After 22 days of feeder free culture, the expression profiles of CD235a+, CD34+, CD43+ and CD 71+ were analyzed by flow cytometry and Wright-Giemsa staining for differential counting. The oxygen carrying capacity of cultured RBCs was measured using a hemoxanalyser. Results: As a result of inducing these cells via co-culture with murine stromal fibroblasts, all endometrium derived iPSCs were differentiated into erythroblasts with stably yielding over 80% of polychromatic and orthochromatic normoblast. The protocol for complete induction of erythroid lineage cells starting from human endometrial tissue via iPS cells has been optimized. Conclusion: Successful induction of hematopoietic cell fate followed by erythroid differentiation up to erythroblast were achieved in an effort to develop transfusion source. And a complete process of actually deriving iPS cells with discarded surgical hysterectomy specimens has significance in the possibility of expanding the scope of use of theses iPSC cell lines in the future.

The effect of oxygen on interfacial phenomena between slag and copper melt was investigated at 1400 °C. The removal of impurities (iron and silicon) in the copper melt during oxygen blowing was confirmed. Also, it was revealed that composition change of the slag occurs due to the oxygen potential in the slag depending on the oxygen injection method. In addition, over-blowing of oxygen after removing impurities is a factor that significantly changes the surface tension of molten copper and slag. Over blown oxygen increases the instability of the interface by reducing interfacial tension between slag and liquid copper. Due to lowered interfacial tension and increased instability, copper droplets can be mixed into slag phase which induces copper loss. Oxygen blowing and/or bubbling is involved in chemical and weak physical reactions in the gas-slag-metal multiphase system, which should be carefully controlled because it is significant factor affecting the recovery rate of the metal. Overall reactions and slag/metal interfacial phenomena in impurity removal regime and over-blowing regime for (a) bottom blowing and (b) top blowing conditions.

BACKGROUND AND PURPOSE Although body weight variability has been associated with mortality, cardiovascular disease, and dementia, the relationship between body weight variability and Parkinson disease (PD) has rarely been studied. We aimed to investigate the longitudinal association between body weight variability and PD incidence. METHODS A nationwide population-based, cohort study was conducted using the database from the Health Insurance Review and Assessment Service of the whole Korean population. We analyzed 2,815,135 participants (≥40 years old, mean age = 51.7 ± 8.6 years, 66.8% men) without a previous PD diagnosis. We determined individual body weight variability from baseline weight and follow-up visits. We used Cox proportional hazards regression models. RESULTS The highest quartile group was associated with increased PD incidence compared with the lowest quartile group after adjustment for confounding factors (hazard ratio [HR] = 1.18, 95% confidence interval [CI] = 1.08-1.29). In contrast, baseline body mass index, baseline waist circumference, and waist circumference variability were not associated with increased PD incidence. In the body weight loss group, individuals within the quartile of the highest variation in body weight showed a higher HR of PD risk than those within other quartiles (HR = 1.41, 95% CI = 1.18-1.68). CONCLUSIONS Body weight variability, especially weight loss, was associated with higher PD incidence. This finding has important implications for clinicians and supports the need for preventative measures and surveillance for PD in individuals with fluctuating body weight.

PURPOSE To determine whether the dose-response association between alcohol consumption and the risk of biliary tract cancer (BTC), including cholangiocarcinoma (CCA) and gallbladder cancer (GBC), differs according to glycemic status. PATIENTS AND METHODS This nationwide cohort study included 9,520,629 individuals age ≥ 20 years without a history of cancer who underwent national health screening under the Korean National Health Insurance Service in 2009. The participants were followed up until December 2018 for BTC development. Cox proportional hazard regression analysis was performed to estimate risk. RESULTS During the 78.3 million person-years of follow-up, 21,079 patients were newly diagnosed with BTC. In individuals with prediabetes and diabetes, light-to-moderate alcohol consumption increased the risk of CCA (adjusted hazard ratio [aHR], 1.20; 95% CI, 1.13 to 1.28 and aHR, 1.58; 95% CI, 1.47 to 1.69) and GBC (aHR, 1.18; 95% CI, 1.07 to 1.31 and aHR, 1.45; 95% CI, 1.28 to 1.64). In normoglycemic individuals, light-to-moderate alcohol consumption was not associated with CCA or GBC risk. When heavy alcohol consumption was combined with diabetes, CCA and GBC risk increased synergistically (aHR, 2.04; 95% CI, 1.83 to 2.26; and aHR, 1.65; 95% CI, 1.33 to 2.04, respectively; all P < .001). Prediabetes and heavy alcohol consumption had a synergistic interactive effect on CCA and GBC risks (all P < .001). Comparable results were obtained for intrahepatic and extrahepatic CCA analyses. CONCLUSION Even light-to-moderate alcohol consumption was associated with an increased risk of BTC in individuals with prediabetes and diabetes, but not in normoglycemic individuals. Complete avoidance of alcohol consumption may help reduce the risk of BTC in patients with prediabetes and diabetes, suggesting the need for individualized prevention strategies for BTC.

Existing studies show that women are more susceptible to chronic obstructive pulmonary disease (COPD) and asthma, and that obesity affects the risk of these airway obstructive diseases. We aimed to determine the effect of body mass index (BMI) and waist circumference (WC) on COPD and asthma development in premenopausal and postmenopausal women.This nationwide population-based cohort study included 1,644,635 women ages ≥30 years without diagnosis of COPD or asthma, who underwent national cancer screening in 2009. We classified them as premenopausal and postmenopausal women based on their menopause status at the time of cancer screening. Baseline BMI and WC were measured, and they were classified into five BMI groups (18.5 kg/m2, 18.5-23 kg/m2, 23-25 kg/m2, 25-30 kg/m2, and ≥30 kg/m2) and WC groups (60 cm, 65-75 cm, 75-85 cm, 85-95 cm, and ≥95 cm). The hazard ratios (HRs) for COPD and asthma were measured for each group.Regardless of the menopausal status, the high BMI and WC groups had a significantly higher COPD and asthma incidence than that of the normal group, and the HRs increased further with increases in BMI and WC. However, the HR in the underweight group was significantly higher among the postmenopausal women. The HR for asthma in the obese group was significantly higher for both premenopausal and postmenopausal women. The HR for COPD was significantly higher in the group with a WC of ≥95 cm for both premenopausal and postmenopausal women, respectively; the HR for asthma was also significantly higher in this group.Obesity and abdominal obesity are risk factors for COPD and asthma in premenopausal and postmenopausal Korean women. Controlling weight and maintaining a healthy body shape can help prevent COPD and asthma in women.

Chromium is normally added to liquid alloy in the form of different grades of ferrochromium (FeCr) alloys for the requirement of different alloy grades, such as stainless steels, high Cr cast iron, etc.. In this work, inclusions in two commercially produced alloys, i.e., high-carbon ferrochromium (HCFeCr) and low-carbon ferrochromium (LCFeCr) alloys, were investigated. The FeCr alloy/liquid iron interactions at an early stage were investigated by inserting solid alloy piece into contact with the liquid iron for a predetermined time using the liquid-metal-suction method. After quenching these samples, a diffusion zone between the alloys and the liquid Fe was studied based on the microstructural characterizations. It was observed that Cr-O-(Fe) inclusions were formed in the diffusion zone, FeO x inclusions were formed in the bulk Fe, and an “inclusion-free” zone was detected between them. Moreover, it was found that the HCFeCr was slowly dissolved, but LCFeCr alloy was rapidly melted during the experiment. The dissolution and melting behaviors of these two FeCr alloys were compared and the mechanism of the early-stage dissolution process of FeCr alloys in the liquid Fe was proposed.

ObjectiveTo investigate the longitudinal association among high-density lipoprotein cholesterol (HDL-C) level, HDL-C variability, and the risk of developing Parkinson disease (PD).MethodsWe conducted a nationwide, population-based cohort study. We included 382,391 patients aged ≥65 years who underwent at least 3 health examinations provided by the Korean National Health Insurance System from 2008 to 2013 and followed up until 2017. Individuals with a history of PD and missing values were excluded (n = 1,987). We assessed HDL-C variability using 3 indices, including variability independent of the mean (VIM). A multivariate-adjusted Cox proportional hazards regression analysis was performed.ResultsAmong the 380,404 participants, 2,733 individuals were newly diagnosed with PD during a median follow-up period of 5 years. The lowest quartile (Q1) group of baseline HDL-C and mean HDL-C was associated with increased PD incidence as compared with the highest quartile (Q4) group (adjusted hazard ratio [aHR], 1.20; 95% confidence interval [CI], 1.08–1.34; and aHR, 1.16; 95% CI, 1.04–1.30, respectively). The Q4 group of HDL-C variability (VIM) was associated with increased PD incidence compared to the Q1 group (aHR, 1.19; 95% CI, 1.06–1.33). The group with the Q1 of baseline HDL-C and with the Q4 of HDL-C variability had the highest risk of PD incidence (aHR, 1.6; 95% CI, 1.31–1.96).ConclusionLower HDL-C level and greater HDL-C variability were associated with a higher incidence of PD.

Objective Pleural adhesion makes video-assisted thoracoscopic surgery (VATS) an arduous procedure and can increase postoperative pain from accompanying adhesiolysis. For the present study, the feasibility of lung ultrasonography for the prediction of pleural adhesions and postoperative pain in VATS was investigated. Design Blinded, prospective, observational study. Setting Tertiary teaching hospital, Seoul, South Korea. Participants Sixty patients (American Society of Anesthesiologists physical status I to III) scheduled to undergo VATS were assessed for eligibility. After exclusions, 53 patients were enrolled and followed-up. Interventions None. Measurements and Main Results Patients were evaluated with lung ultrasonography during deep spontaneous respiration before induction of anesthesia, and surgeons confirmed the presence of pleural adhesions during the surgery. Pain was evaluated using a numeric rating scale and by the amount of opioid consumption until 24 hours postoperatively. Lung ultrasonography showed acceptable predictability of pleural adhesions, with the area under the receiver operating characteristic curve (0.75, 95% confidence interval [CI] 0.67-0.83) and high specificity (0.97, 95% CI 0.91-0.99) but low sensitivity (0.53, 95% CI 0.38-0.68). The pain score was not different between sonographic adhesion (+) and (–) groups; however, the sonographic adhesion (+) group consumed more opioids until 24 hours postoperatively (fentanyl 675 [558-805] μg v 420 [356-476] μg; p Conclusions Lung ultrasonography may help with planning postoperative pain management in VATS; however, it was a better tool for ruling out rather than detecting pleural adhesions.

Nb is an important microalloying element in steelmaking. Its interaction with liquid Fe during an early stage of the alloying process has a considerable influence on the Nb recovery. In the present ...

Gold solubility in the CaO-SiO2-Al2O3-Fe2O3 slag system was measured at 1723 K under an oxidizing atmosphere. Gold solubility in the present slag system increased with increasing slag basicity, which was quantified by the Vee ratio (= CaO/SiO2), theoretical optical basicity, and activity of CaO. However, the effect of Fe2O3 and Al2O3 on gold solubility was negligible. From the thermodynamic assessment, it was found that gold was stabilized as the AuO− (aurate) complex ion, and thus the dissolution reaction into the slag was proposed. The aurate capacity was originally defined from the dissolution reaction. The iso-Au solubility contours were plotted in the CaO-Fe2O3-(SiO2 + Al2O3) pseudo-ternary diagram, from which the lower content of CaO can be proposed to be useful for higher recovery of gold (i.e., lower solubility) based on the thermodynamic view during pyrometallurgical processing of gold-containing E-waste materials. However, because the viscosity of the slag increases by decreasing the content of CaO, the operating window for best practice should be carefully proposed by considering the physicochemical properties of molten slag.

The impact of obesity could differ according to menopausal status since women undergo significant physiologic and metabolic changes due to menopause. We investigated the association between various major obesity indicators and the risk of impaired fasting glucose (IFG) according to menopausal status using nationally representative data. A total of 571,286 premenopausal and 519,561 postmenopausal women who underwent both Korean National Health Insurance Service (NHIS) cancer screening in 2009 and health check-ups in 2017 were analyzed. Multivariate logistic regression analyses were used to assess the effect of independent variables of body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) in 2009, on dependent variable IFG in 2017. After adjusting for potential confounders, the adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of developing IFG were analyzed. In the premenopausal group, the OR of obese BMI (≥25 kg/m2

This study was performed to evaluate etiologies and secular trends in primary amenorrhea in South Korea.This retrospective multi-center study analyzed 856 women who were diagnosed with primary amenorrhea between 2000 and 2016. Clinical characteristics were compared according to categories of amenorrhea (hypergonadotropic/hypogonadotropic hypogonadism, eugonadism, disorders of sex development) or specific causes of primary amenorrhea. In addition, we assessed secular trends of etiology and developmental status based on the year of diagnosis.The most frequent etiology was eugonadism (39.8%). Among specific causes, Müllerian agenesis was most common (26.2%), followed by gonadal dysgenesis (22.4%). Women with hypergonadotropic hypogonadism were more likely to have lower height and weight, compared to other categories. In addition, the proportion of cases with iatrogenic or unknown causes increased significantly in hypergonadotropic hypogonadism category, but overall, no significant secular trends were detected according to etiology. The proportion of anovulation including polycystic ovarian syndrome increased with time, but the change did not reach statistical significance.The results of this study provide useful clinical insight on the etiology and secular trends of primary amenorrhea. Further large-scale, prospective studies are necessary.

The demand for bio-based retinol (vitamin A) is currently increasing, however its instability represents a major bottleneck in microbial production. Here, we developed an efficient method to selectively produce retinol in Yarrowia lipolytica. The β-carotene 15,15'-dioxygenase (BCO) cleaves β-carotene into retinal, which is reduced to retinol by retinol dehydrogenase (RDH). Therefore, to produce retinol, we first generated β-carotene-producing strain based on a high-lipid-producer via overexpressing genes including heterologous β-carotene biosynthetic genes, GGS1

Objectives. Human amniotic membrane extract (AME) is known to contain numerous bioactive factors and anti-inflammatory substances. However, the anti-inflammatory effects of AME on the middle ear (ME) mucosa are unclear. This study assessed the effects of AME on the growth of the ME mucosa in response to bacterially-induced otitis media (OM).Methods. OM was induced by inoculating nontypeable Haemophilus influenzae (NTHi) into the ME cavity of rats. ME mucosal explants were cultured in AME concentrations of 0, 5, 10, or 50 μg/mL. The area of explant outgrowth was measured in culture and analyzed at 1, 3, 5, and 7 days after explantation. The expression of Ki-67, mucin 5AC (MUC5AC), tumor necrosis factor-α (TNF-α), and interleukin-10 (IL-10) in the explants was also evaluated using quantitative polymerase chain reaction (PCR) and immunocytochemistry (ICC).Results. The NTHi-induced ME mucosa growth increased gradually over the 7-day culture period in all explants at different AME concentrations. There was a trend for mucosal growth inhibition at higher concentrations of AME, although the growth was not significantly different among the groups until day 5. The ME mucosal explants treated with the 50 μg/mL concentration of AME showed significantly suppressed growth on postexplantation day 7 compared with other explants on the same day. PCR and ICC staining revealed that the expression of Ki-67, MUC5AC, TNF-α, and IL-10 further decreased in the explants with higher concentrations of AME than in those with lower concentrations of AME.Conclusion. Our results showed that higher concentrations of AME reduced the mucosal proliferative response in bacterial OM in rats. These findings provide evidence that AME has an influence on the inflammatory and proliferative responses to NTHi infection in ME mucosa.

The specific distribution characteristics of inclusions along with the sliver defect were analyzed in detail to explain the formation mechanism of the sliver defect on the automobile exposed panel surface. A quantitative electrolysis method was used to compare and evaluate the three-dimensional morphology, size, composition, quantity, and distribution of inclusions in the defect and non-defect zone of automobile exposed panel. The Al2O3 inclusions were observed to be aggregated or chain-like shape along with the sliver defect of about 3–10 µm. The aggregation sections of the Al2O3 inclusions are distributed discretely along the rolling direction, with a spacing of 3–7 mm, a length of 6–7 mm, and a width of about 3 mm. The inclusion area part is 0.04%–0.16% with an average value of 0.08%, the inclusion number density is 40 mm−2 and the inclusion average spacing is 25.13 µm. The inclusion spacing is approximately 40–160 µm, with an average value of 68.76 µm in chain-like inclusion parts. The average area fraction and number density of inclusions in the non-defect region were reduced to about 0.002% and 1–2 mm−2, respectively, with the inclusion spacing of 400 µm and the size of Al2O3 being 1–3 µm.

Background: The association of metabolic syndrome and its components with the risk of thyroid cancer is unclear. Thus, we conducted a large-scale, nationwide, population-based, cohort study to inve...

Background The effects of far-infrared radiation (FIR) on the treatment of rotator cuff diseases remains unknown. We evaluated the safety and efficacy of FIR after arthroscopic rotator cuff repair with regard to postoperative pain and healing. Methods This prospective randomized comparative study included 38 patients who underwent arthroscopic rotator cuff repair due to a medium-sized tear. Patients were randomly divided into the FIR or control group (n = 19 per group). In the FIR group, FIR with an FIR radiator started 1 week postoperatively for 30 minutes per session twice daily. It lasted until abduction brace weaning at 5 weeks postoperatively. We assessed pain using a pain visual analogue scale (pVAS) and measured the range of motion (ROM) of the shoulder at 5 weeks, and 3 and 6 months, postoperatively. The anatomical outcome was evaluated using magnetic resonance imaging at 6 months postoperatively. Results At 5 weeks postoperatively, the average pVAS score was lower in the FIR group than in the control group (1.5 ± 0.8 vs. 2.7 ± 1.7; P = 0.019). At 3 months postoperatively, the average forward flexion was higher in the FIR group (151.6° ± 15.3° vs. 132.9° ± 27.8°; P = 0.045), but there was no significant difference at 6 months postoperatively. There was no significant difference in healing failure between the groups (P = 0.999). Conclusions FIR after arthroscopic rotator cuff repair could be an effective and safe procedure to reduce postoperative pain, thereby facilitating rehabilitation and better ROM in the early postoperative period.

The effect of CaF2 addition on dephosphorization reaction between molten steel and electric arc furnace (EAF) slag using direct reduced iron (DRI) at 1823 K (1550 °C) was investigated. Basicity, the thermodynamic parameter affecting the removal capacity of phosphorus (i.e., phosphate capacity), decreased using DRI due to an increased SiO2 concentration in the slag. To minimize slag volume and maximize dephosphorization efficiency, the CaF2 was added to the slag. As CaF2 content increased (0 to 10 mass pct), dephosphorization efficiency also increased. Thermodynamic analysis in conjunction with slag structural studies using Raman spectroscopy were conducted to explain the complicated phenomena. The results exhibited that even 5 to 6 mass pct CaF2 can improve the dephosphorization efficiency when DRI is used as raw material in an EAF process.

Objective This study aimed to confirm the accuracy of a machine-learning-based model in predicting the 30-day mortality of patients with pneumonia and evaluating whether they were required to be admitted to the intensive care unit (ICU). Methods The study conducted a retrospective analysis of pneumonia patients at an emergency department (ED) in Seoul, Korea, from January 1, 2016 to December 31, 2017. Patients aged 18 years or older with a pneumonia registry designation on their electronic medical record were enrolled. We collected their demographic information, mental status, and laboratory findings. Three models were used: the pre-existing CURB-65 model, and the CURB-RF and Extensive CURB-RF models, which were machine-learning models that used a random forest algorithm. The primary outcomes were ICU admission from the ED or 30-day mortality. Receiver operating characteristic curves were constructed for the models, and the areas under these curves were compared. Results Out of the 1,974 pneumonia patients, 1,732 patients were eligible to be included in the study; from these, 473 patients died within 30 days or were initially admitted to the ICU from the ED. The area under receiver operating characteristic curves of CURB-65, CURB-RF, and extensive-CURB-RF were 0.615 (0.614-0.616), 0.701 (0.700-0.702), and 0.844 (0.843-0.845), respectively. Conclusion The proposed machine-learning models could predict the mortality of patients with pneumonia more accurately than the pre-existing CURB-65 model and can help decide whether the patient should be admitted to the ICU.

The formation of multiphase inclusions was investigated in resulphurised steel. Samples were taken at different stages of the steelmaking process, from primary deoxidation through calcium modificat ...

OBJECTIVE Obesity and type 2 diabetes are risk factors for cardiovascular diseases and mortality, and they commonly result in weight variabilities. We aimed to investigate the association between body weight variability and risk of major cardiovascular outcomes and mortality in individuals with type 2 diabetes using large-scale, nationwide cohort data on the Korean population. RESEARCH DESIGN AND METHODS We enrolled 624,237 individuals with type 2 diabetes who underwent health examinations provided by the Korean National Health Insurance System between 2009 and 2010, with three or more body weight measurements within 5 years since enrollment and followed up until the end of 2017. We assessed body weight variability using four indices, including variability independent of the mean (VIM). A multivariate-adjusted Cox proportional hazards regression analysis was performed. RESULTS During the follow-up, 15,832, 25,038, and 44,716 cases of myocardial infarction (MI), stroke, and all-cause mortality, respectively, were recorded. Body weight variability was associated with increased risks of major cardiovascular outcomes after adjusting for confounding variables. Compared with the hazard ratios (HRs) of the lowest quartile group, the HRs (95% CIs) of the highest quartile group of VIM for body weight were 1.15 (1.10–1.20), 1.22 (1.18–1.26), and 1.58 (1.53–1.62) for MI, stroke, and all-cause mortality, respectively. CONCLUSIONS Body weight variability was associated with increased risks of MI, stroke, and all-cause mortality in patients with type 2 diabetes and may be a predictor of cardiovascular outcomes in such patients. Appropriate interventions to maintain stable weight could positively influence health outcomes in patients with type 2 diabetes.

Fluorspar (CaF2) has been widely used to control the physicochemical properties of slag in steelmaking processes. However, it is very important to reduce the CaF2 consumption because it causes various environmental problems. In the current study, therefore, the effect of industrial waste materials such as red mud (RM) and ferromanganese slag (FMS) on the desulfurization behavior of molten steel was investigated to find potential substitutes for fluorspar. Compared to conventional 10 pct CaF2-containing ladle slag, when excess industrial wastes were added (i.e., more than 10 mass pct), the composition of the slag was dramatically changed (SiO2 increases, while FetO and MnO decrease). Therefore, the sulfide capacity of the slag decreased, and the viscosity of the slag increased. Thus, the desulfurization efficiency was also reduced. However, when the RM or FMS were added not more than 10 mass pct to lean-CaF2 (3 pct) slag, the sulfide capacity of the slag was equivalent to 10 pct CaF2-containing ladle slag; thus, the desulfurization efficiency was also equivalent with lower melting point and higher fraction of liquid phase. Consequently, it was confirmed that a small amount (less than 10 mass pct) of industrial wastes can be added as a desulfurization fluxing agent as a partial substitute for fluorspar.