The economic value of sustainable recycling and waste management policies: The case of a waste management crisis in South Korea.

The price of recyclable waste has declined, and China is refusing solid waste imports. As a result, recycling companies in South Korea are refusing to collect recyclable waste, which caused a solid waste management crisis in April 2018. Due to this crisis, many people are unable to discard their recyclable waste. This study aims to assess the economic value of a sustainable recycling and waste management policy to solve the waste management crisis. The analysis in this study is divided into two parts: The first part estimates the inconvenience costs to residents using a contingent valuation method, whereas the second part analyzes the preferences for a new policy using a mixed logit model with a choice experiment. The results show that mean willingness to pay (WTP) per household is 41,234 (USD 36.96) KRW/year; the total WTP would be able to increase the total disposal capacity by up to 4.51%. In addition, at an adequate price level for the policy alternative, the policy acceptance rate suggests that the price of biodegradable volume-rate disposal bags should increase by no more than KRW 66 (USD 0.06) per bag. This study provides guidance to policy makers who wish to consider both validity and acceptability.

Comparison of echocardiography with dual-source computed tomography for assessment of left ventricular volume in healthy Beagles.

OBJECTIVE: To compare echocardiographic measurements of left ventricular (LV) volume obtained via a modified Simpson or Teichholz method with those obtained via dual-source CT (DSCT). ANIMALS: 7 healthy Beagles. PROCEDURES: Each dog was anesthetized for DSCT; LV volume was determined from contrast-enhanced images of the LV lumen during all phases of contraction. Echocardiography was performed with dogs awake and anesthetized. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume, and ejection fraction were measured via a modified Simpson method and Teichholz method. Each dog was anesthetized twice with a 1-week interval between anesthetic sessions. RESULTS: Results obtained while dogs were anesthetized revealed that the modified Simpson method underestimated LV volume (mean ± SD EDV, 24.82 ± 2.38 mL; ESV, 12.24 ± 1.77 mL), compared with that estimated by the Teichholz method (EDV, 32.57 ± 2.85 mL; ESV, 14.87 ± 2.09 mL) or DSCT (EDV, 34.14 ± 1.57 mL; ESV, 16.71 ± 0.76 mL). Ejection fraction (modified Simpson method, 48.53% ± 4.24%; Teichholz method, 54.33% ± 4.26%; DSCT, 51.00% ± 2.71%) differed significantly among the 3 methods. Echocardiographic results obtained while dogs were awake revealed that EDV, ESV, and stroke volume differed significantly between the modified Simpson and Teichholz methods. CONCLUSIONS AND CLINICAL RELEVANCE: LV volume determined via the Teichholz method was more similar to that determined via DSCT than was the LV volume determined via the modified Simpson method. The modified Simpson method underestimated LV volume, compared with that obtained via the Teichholz method, in both anesthetized and awake dogs.

Comprehensive evaluation of coronary artery disease and aortic atherosclerosis in acute ischemic stroke patients: usefulness based on Framingham risk score and stroke subtype.

BACKGROUND: Evaluation of coronary artery disease (CAD) and aortic atherosclerosis has been performed in patients with acute ischemic stroke. We investigated the usefulness of a dual-source CT (DSCT) protocol enabling the comprehensive evaluation of CAD and aortic atherosclerosis. The clinical characteristics of those patients who would benefit more from this protocol were investigated based on vascular risk factors, Framingham Risk Score (FRS), and stroke subtype. METHODS: Of 469 patients with acute ischemic stroke, the 274 who had no history of CAD and had undergone DSCT were analyzed. Predictors of CAD (≥50% stenosis) or complicated aortic plaque (CAP) were evaluated based on vascular risk factors, FRS and stroke subtype. RESULTS: Of the 274 patients analyzed, asymptomatic CAD (≥50% stenosis) was found in 61 (22.3%) and CAP in 58 (21.2%). Furthermore, the severity of CAD or aortic atherosclerosis was correlated with FRS (CAD, r = 0.291, p < 0.001 and aortic atherosclerosis, r = 0.297, p < 0.001). Additionally, severe CAD and aortic atherosclerosis were independent predictors of each other: CAP for the presence of CAD (≥50% stenosis) [odds ratio (OR), 5.71; 95% confidence interval (CI), 1.94-16.87]; CAD (≥50% stenosis) for the presence of CAP (OR, 4.20; 95% CI, 1.82-9.72). Specific stroke subtypes as well as large-artery atherosclerosis (OR, 5.25; 95% CI, 2.24-12.31) and cardioembolism (OR, 5.22; 95% CI, 1.75-15.60) were associated with the presence of CAP. CONCLUSIONS: A comprehensive evaluation protocol for CAD and aortic atherosclerosis may be useful in acute ischemic stroke patients, especially in those with higher FRS or specific stroke subtypes.

Surgical correction of cor triatriatum associated with pulmonary artery thrombosis in an adult.

We herein present a case of a successful correction of cor triatriatum associated with thrombotic pulmonary hypertension diagnosed in an adult female patient. We confirmed diagnosis using transthoracic and transesophageal echocardiography in addition to cardiac computed tomography and magnetic resonance imaging. Surgical repair comprised excision of the fibromuscular membranous septum in the left atrium, patch closure of an atrial septal defect, and reconstruction of the pulmonary arteries with a vascular graft. Cor triatriatum complicated pulmonary thrombotic hypertension with atrial septal defect is amenable to surgical correction with satisfactory results.

Force field design and molecular dynamics simulations of factor-inhibiting HIF-1 and its complex with known inhibitors: implications for rational inhibitor design.

Based on molecular dynamics simulations in aqueous solution, we investigate the dynamic properties of factor-inhibiting HIF-1 (FIH1) and its complexes with the substrate 2-oxoglutarate (2OG) and the two known inhibitors, N-oxalylglycine (NOG) and N-oxalyl-D-phenylalanine (NODP). The results obtained with the newly developed force field parameters for the coordination environment of the active-site ferrous ion show that FIH1 undergoes a significant conformational stabilization with a decrease in motional amplitude upon binding of the substrate or the inhibitors. Two loop structures around the active-site reveal a high flexibility in the resting form of FIH1 with the high B-factor values. These high-amplitude motions of the flexible loops are found to be weakened significantly in the presence of the substrate or a weak inhibitor (NOG), and damped out upon binding of a potent and selective inhibitor (NODP) in the active site. A characteristic feature that discriminates the coordination structures of the active-site ferrous ion in complex with 2OG and NOG in solution from those in the X-ray crystal structures lies in the presence of a structural water molecule from bulk solvent at the sixth coordination position, which leads to the formation of a stable octahedral coordination geometry. However, the approach of such a structural water molecule to the active-site ferrous ion is prohibited in the FIH1-NODP complex, which should be attributed to the formation of hydrophobic contacts between the phenyl ring of the inhibitor and the side chains of Tyr102, Leu186, and Trp296 at the entrance of the active site. This indicates that the D-enantiomeric side-chain phenyl group of NODP should play an essential role in potent and selective inhibition of FIH1.

Structure-based virtual screening approach to the discovery of novel inhibitors of factor-inhibiting HIF-1: identification of new chelating groups for the active-site ferrous ion.

The inhibitors of factor-inhibiting HIF-1 (FIH1) have been shown to be useful as therapeutics for the treatment of anemia. We have been able to identify eight novel FIH1 inhibitors with IC(50) values ranging from 30 to 80microM by means of the virtual screening with docking simulations under consideration of the effects of ligand solvation in the scoring function. The newly identified inhibitors are structurally diverse and have various chelating groups for the active-site ferrous ion including sulfonamide, carboxylate, N-benzo[1,2,5]oxadiazol-4-yl amide, and 2-[1,2,4]triazolo[3,4-b]][1,3,4]thiadiazol-3-yl-quinoline moieties. Each of these four structural classes has not been reported as FIH1 inhibitor, and therefore can be considered for further development by structure-activity relationship or denovo design methods. The interactions with the amino acid residues responsible for the stabilizations of the inhibitors in the active site are addressed in detail.

Nanosecond molecular dynamics simulations of Cdc25B and its complex with a 1,4-naphthoquinone inhibitor: implications for rational inhibitor design.

Cdc25 phosphatases have been considered as attractive drug targets for anticancer therapies due to the correlation of their overexpression with a wide variety of cancers. To gain insight into designing new potent inhibitors, we investigate the dynamic properties of Cdc25B and its complex with a 1,4-naphtoquinone inhibitor NSC 95397 by means of molecular dynamics simulations in aqueous solution. It is shown from the calculated dynamic properties that the malleability of the residues 530-532 residing at the start of C-terminal region around the active site should be responsible for the catalytic action of Cdc25B. However, binding of the inhibitor in the active site leads to a substantial decrease in the motional amplitude of the flexible residues, due to the hydrophobic interactions with the side chain of Met531. The simulation results also indicate that at least four hydrogen bonds are involved in the enzyme-inhibitor complex. Among them, the hydrogen bond between the side chain carboxylate group of Glu478 and one of the hydroxyl groups of the inhibitor is found to be the most significant binding force stabilizing the inhibitor in the active site. This result supports the previous experimental implication that the possession of a single hydroxyl group is sufficient for the inhibitory activity of 1,4-naphthoquinone inhibitors.

Incidence and clinical significance of myocardial bridging with ECG-gated 16-row MDCT coronary angiography.

AIMS: The aims of this study were to evaluate the incidence and the clinical significance of myocardial bridging in 401 patients with chest pain examined with 16-row Multidetector CT (MDCT) coronary angiography. MATERIAL AND METHODS: Four hundred nine consecutive patients who had chest pain or symptoms suggestive of coronary artery disease were involved in this study. Patients with heart rates >or=65 beats/min received 25-50 mg of atenolol orally 1 h before the scan. CT coronary angiography was performed with a 16-row MDCT scanner. CT coronary angiographic images were evaluated by consensus of two radiologists, who were blinded to clinical information. Clinical correlation was made between the presence and type of myocardial bridging on MDCT and the clinical results based on history, examination, and any subsequent clinical workup at the 2-month follow-up by a consensus of two physicians. RESULTS: Among the 401 patients, 23 (5.7%) cases of myocardial bridging were detected. Twenty-one (5.2%) cases of myocardial bridging were located at the middle third of the left anterior descending coronary artery (LAD), one (0.25%) case was at the proximal third of the LAD, and one (0.25%) case was at the distal third of the LAD. Superficial bridging was identified in 15 patients and deep bridging in 8. The length of tunneled artery was between 5 and 27 mm, with a mean of 15.7 mm, and the depth of tunneled artery was between 1.0 and 7.0 mm, with a mean of 3.2 mm. Out of four patients whose chest pain was assumed to be associated with myocardial bridging, three patients had deep bridging. In the other 19 patients with bridging, alternative causes of chest pain were present. CONCLUSIONS: We found the incidence of myocardial bridging in this patient group to be 5.7%. Larger multicenter studies are required to evaluate the incidence of myocardial bridging and to determine a link between myocardial bridging and chest pain.

Early and delayed myocardial enhancement in myocardial infarction using two-phase contrast-enhanced multidetector-row CT.

OBJECTIVE: The purpose of this study was to describe the myocardial enhancement patterns in patients with myocardial infarction using two-phase contrast-enhanced multidetector-row computed tomography (MDCT). MATERIALS AND METHODS: Twenty-three patients with clinically proven myocardial infarction (17 acute myocardial infarction [AMI] and 6 chronic myocardial infarction [CMI]) were examined with two-phase contrast-enhanced ECG-gated MDCT. The presence, location, and patterns of myocardial enhancement on two-phase MDCT images were compared with infarcted myocardial territories determined by using electrocardiogram, echocardiography, thallium-201 single photon emission computed tomography, catheter and MDCT coronary angiography. RESULTS: After clinical assessment, the presence of myocardial infarctions were found in 27 territories (19 AMI and 8 CMI) of 23 patients. Early perfusion defects were observed in 30 territories of all 23 patients. Three territories not corresponding to a myocardial infarction were detected in three patients with AMI and were associated with artifacts. Fourteen of perfusion defects were in the left anterior descending artery territory, four in the left circumflex artery territory, and nine in the right coronary artery territory. Delayed enhancement was observed in 25 territories (17 AMI and 8 CMI) of 21 patients. Delayed enhancement patterns were variable. Transmural early perfusion defects (n =12) were closely associated with transmural late enhancement (n = 5) and subendocardial residual defect with subepicardial late enhancement (n = 5). CONCLUSION: Myocardial infarction showed early perfusion defects and variable delayed enhancement patterns on two-phase contrast-enhanced MDCT. Delayed enhancement technique of MDCT could provide additional information of the location and extent of infarcted myocardium, and could be useful to plan appropriate therapeutic strategies in patients with AMI.