Spatio-temporal variation and hazard assessment of potentially toxic metal element contamination in sediments and water before and after a water-level fluctuation cycle in the Three Gorges Reservoir, Wanzhou, China.

Previous investigations on heavy metals in the water-sediment compartment focused on their spatial distribution, and the influence of sediment pH and organic matter (OM) on metal environmental occurrences. However, there are limited studies on the effects of physicochemical properties on the migration and transformation of heavy metals in the water-sediment compartments. This study investigated the relationship between the physicochemical properties of sediments and the distribution and chemical speciation of heavy metals, and the potential environmental risk of heavy metals in water and sediment using Risk Assessment Code (RAC) values and the Tessier five-step extraction method. Adsorption and desorption experiments showed that the sediment had weak adsorption and the strongest desorption capacity for Cd. Results of the pH, OM, surface element content, and X-ray diffraction (XRD) patterns suggested that cadmium (Cd) was more likely to partition into the water phase from the sediment during the flooding and water storage periods. When pH was 7-8 and OM content was 3.6-5.9%, the sediment-water distribution coefficient of Cd was low due to its large ionic radius, and the surface adsorption sites were saturated by other elements. These studies can provide a theoretical basis for the management and pollution control of the Three Gorges Reservoir.

Association of left ventricular systolic dysfunction with coronary artery dilation in Kawasaki disease patients: Assessment with cardiovascular magnetic resonance.

PURPOSE: To quantify global and regional left ventricular (LV) strain parameters in patients with Kawasaki disease (KD) using cardiovascular magnetic resonance (CMR) tissue tracking and assess the association of coronary artery dilation (CA dilation) with LV systolic dysfunction. METHODS: Thirty-one KD patients with CA dilation, 22 patients without CA dilation and 27 age- and sex-matched normal controls underwent 3.0 T CMR examination. Z score of >2 was defined as CA dilation. Global LV strain parameters and regional LV strain parameters in 16 American Heart Association segmentation, including radial, circumferential and longitudinal peak strain (PS) and LV function were measured and compared among groups. RESULTS: No significant difference in LV ejection fraction has been observed among controls, KD patients with CA dilation and without CA dilation (all p > 0.05). However, global longitudinal PS (GLPS) was lower in groups with CA dilation than those without CA dilation (-12.6 ± 4.1% vs -14.9 ± 2.6%, p < 0.05). For regional strain parameters, the segments with CA dilation (n = 301) were lower than those in both normal controls (n = 416) and segments without CA dilation (n = 547) in regional radial, circumferential and longitudinal PS (all p < 0.05). The severity of CA dilation was positively correlated to GLPS and regional longitudinal PS (r = 0.388 and r = 0.222; both p < 0.05) in KD patients. After adjusting for clinical characteristics, the multivariate analysis demonstrated that Z score was independently associated with GLPS in KD patients (ß = 0.469, p = 0.000, model R2 = 0.355). CONCLUSIONS: CMR tissue tracking could sensitively identify subclinical LV dysfunction in KD patients with CA dilation. LV systolic dysfunction occurs particularly in the myocardium dominated by the dilated coronary artery. CA dilation is an independent predictor of LV systolic dysfunction.

Utility of single-shot compressed sensing cardiac magnetic resonance cine imaging for assessment of biventricular function in free-breathing and arrhythmic pediatric patients.

BACKGROUND: This study aimed to explore the feasibility and accuracy of single-shot compressed-sensing (CS) cardiac magnetic resonance cine technology for the assessment of biventricular function and morphology in free-breathing (FB) pediatrics, especially those with arrhythmia. METHODS: Seventy consecutive pediatric participants (6.27 ± 3.8 years, range:0.5-14 years) were enrolled between August 2019 and July 2020. Single-shot CS and conventional balanced steady-state free-precession (bSSFP) cine were obtained. The total scanning time, image quality and biventricular function parameters were compared for both sequences. RESULTS: Single-shot CS cine had shorter acquisition time compared with the conventional bSSFP cine (all P < 0.001). The single-shot CS cine also had fewer artifacts than conventional bSSFP cine (breath-hold (BH): 4.6 ± 0.6 vs. 4.3 ± 0.6; FB without ongoing arrhythmia: 4.5 ± 0.6 vs. 3.6 ± 0.9; FB with ongoing arrhythmia: 4.7 ± 0.5 vs. 2.6 ± 1.1; all P < 0.05). No statistical difference of left ventricular parameters and right ventricular end-systolic volume/ejection fraction were found between the single-shot CS and conventional bSSFP cine in both BH and FB without ongoing arrhythmia group. There was an excellent correlation (R2 = 0.60-0.98, all P < 0.001) and good intra-(range: R2 = 0.57-0.99, P < 0.001)/inter-observer agreements (range: R2 = 0.76-1, P < 0.001) for single-shot CS cine images in terms of biventricular function parameters. CONCLUSIONS: The single-shot CS cine can significantly reduce the image acquisition time, offering reliable quantification of biventricular function in free breathing condition for arrhythmic patients.

Supporting a circular economy: Insights from Taiwan's plastic waste sector and lessons for developing countries.

This study investigates how, in the process of industrialization, Taiwan successfully developed its plastic waste industry into an industrial-level circular economy by leveraging a network-based collective bricolage in conjunction with a framework of adaptive institutional governance. Three conclusions are made: industrialized manufacturing sectors are foundations upon which developing nations can accumulate endogenous social capabilities and can enable the emergence of network-based collective bricolages; for developing nations that are attempting to establish circular economies based on their endogenous small-to-medium enterprises, developing network-based collective bricolages in conjunction with adaptive institutional governance is an essential and effective strategy; and transitioning into green-related sectors can further drive economic development and lead to the creation of new ventures, businesses, and job opportunities while supporting the formation of a circular economy. The approach is especially relevant for developing countries starting their industrialization process and waste management initiatives with few resources.

Myocardial perfusion assessment in the infarct core and penumbra zones in an in-vivo porcine model of the acute, sub-acute, and chronic infarction.

OBJECTIVES: To assess the longitudinal changes of microvascular function in different myocardial regions after myocardial infarction (MI) using myocardial blood flow derived by dynamic CT perfusion (CTP-MBF), and compare CTP-MBF with the results of cardiac magnetic resonance (CMR) and histopathology. METHODS: The CTP scanning was performed in a MI porcine model 1 day (n = 15), 7 days (n = 10), and 3 months (n = 5) following induction surgery. CTP-MBF was measured in the infarcted myocardium, penumbra, and remote myocardium, respectively. CMR perfusion and histopathology were performed for validation. RESULTS: From baseline to follow-up scans, CTP-MBF presented a stepwise increase in the infarcted myocardium (68.51 ± 11.04 vs. 86.73 ± 13.32 vs. 109.53 ± 26.64 ml/100 ml/min, p = 0.001) and the penumbra (104.92 ± 29.29 vs. 120.32 ± 24.74 vs. 183.01 ± 57.98 ml/100 ml/min, p = 0.008), but not in the remote myocardium (150.05 ± 35.70 vs. 166.66 ± 38.17 vs. 195.36 ± 49.64 ml/100 ml/min, p = 0.120). The CTP-MBF correlated with max slope (r = 0.584, p < 0.001), max signal intensity (r = 0.357, p < 0.001), and time to max (r = - 0.378, p < 0.001) by CMR perfusion. Moreover, CTP-MBF defined the infarcted myocardium on triphenyl tetrazolium chloride staining (AUC: 0.810, p < 0.001) and correlated with microvascular density on CD31 staining (r = 0.561, p = 0.002). CONCLUSION: CTP-MBF could quantify the longitudinal changes of microvascular function in different regions of the post-MI myocardium, which demonstrates good agreement with contemporary CMR and histopathological findings. KEY POINTS: • The CT perfusion-based myocardial blood flow (CTP-MBF) could quantify the microvascular impairment in different myocardial regions after myocardial infarction (MI) and track its recovery over time. • The assessment of CTP-MBF is in good agreement with contemporary cardiac MRI and histopathological findings, which potentially facilitates a rapid approach for pathophysiological insights following MI.

[Accuracy comparison of preoperative histological assessment in differentiation and grading of rectal adenocarcinoma].

OBJECTIVE: To compare the accuracy of preoperative assessment in differentiation and grading of rectal adenocarcinoma. METHODS: One hundred consecutive patients diagnosed as invasive rectal cancer by colonoscopy biopsy and undergone operation in the Changhai Hospital from March 2006 to May 2008 were studied retrospectively. Patient characteristics, examination records, operative and pathologic reports were reviewed. The slides of preoperative biopsy and postoperative pathologic specimen were reviewed to identify the differentiation by a single pathologist. The results of preoperative biopsy were compared to those of postoperative specimen which was considered as final diagnosis. The accuracy of preoperative assessment of differentiation was calculated. Patients were then divided into two groups based on the preoperative differentiation:the low-grade tumor including well and moderately differentiated tumors, and the high-grade tumor consisting of poorly differentiated and undifferentiated tumors. The accuracy of grading was also calculated. RESULTS: The accuracy of preoperative assessment of differentiation was 72%, with 20% overgrading and 8% undergrading, while the accuracy of preoperative grading was 91%, with 4% overgrading and 5% undergrading. The accuracy of grading was significantly higher than that of specific differentiation(P<0.01). CONCLUSION: The grading of preoperative biopsy has high accuracy rate and should be considered in clinical practice.

Time location analysis for exposure assessment studies of indoor workers based on active RFID technology.

In this article, we describe the development of a radio frequency identification exposure monitoring system (RFEMS) suitable for tracking and identifying workers' locations in indoor workplaces. Five workers in southern Taiwan wore the RFEMS integrated into their equipment vests. Location and exposure data were transferred to data analysis software for visualization and tabular analysis in real-time. Data were grouped into seven task activity location categories to determine the time spent and percentage reception in each location. The RFEMS could also synchronously indicate the surrounding conditions using various sensors. Additional experiments were focused on locating of boundaries and determining the instrument stability, power sustainability, and reception efficiency in typical environments. The RFEMS instruments provided adequate range for locating (typically ca. 6-45 m in each zone), allowing us to locate subjects within distinct microenvironments and to distinguish between the activities of a variety of workers, the average time activity pattern (TAP) recording deviation for both human observations and RFEMS was ca. 0.21-1.57%. Power consumption experiments revealed that the system could be sustained for more than 124 h. A pilot field test indicated that the RFEMS offers a new level of accuracy for direct quantification of time activity patterns in exposure assessments of indoor workers over long periods of time.

Potential ecological risk assessment of heavy metal pollution in sediments of the Yangtze River within the Wanzhou section, China.

A potential ecological risk assessment was conducted based on the analyzing results of the typical pollutants (Pb, Cu, Cr, Cd, and Zn) contents in the sediments of Yangtze River within the Wanzhou section using the index number techniques of single factor and Hakanson method for the quality status of the sediments. The results indicted that cadmium (Cd) had the largest pollution index and was the main pollution factor among the metals. The ecological risk sequence of the metals was Cd > Zn >Pb > Cu >Cr, while the sequence of the potential ecological risk posed by the metals was Cd > Pb > Cu> Zn >Cr. The index range of potential ecological risk was from 101.39 to 184.31, and the average index of potential ecological risk factors (RI) was 152.35. The Yangtze River within the Wanzhou section has a middle potential ecological risk.