| 11. |
- Hu, Li-Xin, et al.
(författare)
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What is in Nigerian waters? Target and non-target screening analysis for organic chemicals
- 2021
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 284
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Tidskriftsartikel (refereegranskat)abstract
- Emerging organic contaminants (e.g., active pharmaceutical ingredients and personal care products ingredients) are ubiquitous in the environment and potentially harmful to ecosystems, have gained increasing public attention worldwide. Nevertheless, there is a scarcity of data on these contaminants in Africa. In this study, various types of water samples (wastewater, surface water and tap water) collected from Lagos, Nigeria were analyzed for these chemicals by both target and non-target analysis on an UHPLC-Orbitrap-MS/MS. In total, 109 compounds were identified by non-target screening using the online database mzCloud. Level 1 identification confidence was achieved for 13 compounds for which reference standards were available and level 2 was achieved for the rest. In the quantitative analysis, 18 of 38 target compounds were detected, including the parent compounds and their metabolites. Acetaminophen, sulfamethoxazole, acesulfame, and caffeine were detected in all samples with their highest concentrations at 8000, 5300, 16, and 7700 μg/L in wastewater, 140000, 3300, 7.7, and 12000 μg/L in surface water, and 66, 62, 0.17 and 1000 μg/L in tap water, respectively. The occurrence of psychoactive substances, anticancer treatments, antiretrovirals, antihypertensives, antidiabetics and their metabolites were reported in Nigeria for the first time. These results indicate poor wastewater treatment and management in Nigeria, and provide a preliminary profile of organic contaminants occurring in Nigerian waters. The findings from this study urge more future research on chemical pollution in the aquatic environments in Nigeria.
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| 12. |
- McEvoy, John W., et al.
(författare)
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Isolated Diastolic Hypertension in the IDACO Study : An Age-Stratified Analysis Using 24-Hour Ambulatory Blood Pressure Measurements
- 2021
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Ingår i: Hypertension. - : Wolters Kluwer. - 0194-911X .- 1524-4563. ; 78:5, s. 1222-1231
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Tidskriftsartikel (refereegranskat)abstract
- The prognostic implications of isolated diastolic hypertension (IDH), as defined by 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines, have not been tested using ambulatory blood pressure (BP) monitor thresholds (ie, 24-hour mean systolic BP <125 mm Hg and diastolic BP >= 75 mm Hg). We analyzed data from 11 135 participants in the IDACO (International Database on Ambulatory Blood Pressure in Relation to Cardiovascular Outcomes). Using 24-hour mean ambulatory BP monitor values, we performed Cox regression testing independent associations of IDH with death or cardiovascular events. Analyses were conducted in the cohort overall, as well as after age stratification (<50 years versus >= 50 years). The median age at baseline was 54.7 years and 49% were female. Over a median follow-up of 13.8 years, 2836 participants died, and 2049 experienced a cardiovascular event. Overall, irrespective of age, IDH on 24-hour ambulatory BP monitor defined by 2017 American College of Cardiology/American Heart Association criteria was not significantly associated with death (hazard ratio, 0.95 [95% CI, 0.79-1.13]) or cardiovascular events (hazard ratio, 1.14 [95% CI, 0.94-1.40]), compared with normotension. However, among the subgroup <50 years old, IDH was associated with excess risk for cardiovascular events (2.87 [95% CI, 1.72-4.80]), with evidence for effect modification based on age (P interaction <0.001). In conclusion, using ambulatory BP monitor data, this study suggests that IDH defined by 2017 American College of Cardiology/American Heart Association criteria is not a risk factor for cardiovascular disease in adults aged 50 years or older but is a risk factor among younger adults. Thus, age is an important consideration in the clinical management of adults with IDH.
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| 13. |
- Melgarejo, Jesus D., et al.
(författare)
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Association of Fatal and Nonfatal Cardiovascular Outcomes With 24-Hour Mean Arterial Pressure
- 2021
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Ingår i: Hypertension. - : Wolters Kluwer. - 0194-911X .- 1524-4563. ; 77:1, s. 39-48
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Tidskriftsartikel (refereegranskat)abstract
- Major adverse cardiovascular events are closely associated with 24-hour blood pressure (BP). We determined outcome-driven thresholds for 24-hour mean arterial pressure (MAP), a BP index estimated by oscillometric devices. We assessed the association of major adverse cardiovascular events with 24-hour MAP, systolic BP (SBP), and diastolic BP (DBP) in a population-based cohort (n=11 596). Statistics included multivariable Cox regression and the generalized R-2 statistic to test model fit. Baseline office and 24-hour MAP averaged 97.4 and 90.4 mm Hg. Over 13.6 years (median), 2034 major adverse cardiovascular events occurred. Twenty-four-hour MAP levels of <90 (normotension, n=6183), 90 to <92 (elevated MAP, n=909), 92 to <96 (stage-1 hypertension, n=1544), and >= 96 (stage-2 hypertension, n=2960) mm Hg yielded equivalent 10-year major adverse cardiovascular events risks as office MAP categorized using 2017 American thresholds for office SBP and DBP. Compared with 24-hour MAP normotension, hazard ratios were 0.96 (95% CI, 0.80-1.16), 1.32 (1.15-1.51), and 1.77 (1.59-1.97), for elevated and stage-1 and stage-2 hypertensive MAP. On top of 24-hour MAP, higher 24-hour SBP increased, whereas higher 24-hour DBP attenuated risk (P<0.001). Considering the 24-hour measurements, R-2 statistics were similar for SBP (1.34) and MAP (1.28), lower for DBP than for MAP (0.47), and reduced to null, if the base model included SBP and DBP; if the ambulatory BP indexes were dichotomized according to the 2017 American guideline and the proposed 92 mm Hg for MAP, the R-2 values were 0.71, 0.89, 0.32, and 0.10, respectively. In conclusion, the clinical application of 24-hour MAP thresholds in conjunction with SBP and DBP refines risk estimates.
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| 14. |
- Melgarejo, Jesus D., et al.
(författare)
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Relative and Absolute Risk to Guide the Management of Pulse Pressure, an Age-Related Cardiovascular Risk Factor
- 2021
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Ingår i: American Journal of Hypertension. - : Oxford University Press. - 0895-7061 .- 1941-7225. ; 34:9, s. 929-938
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND Pulse pressure (PP) reflects the age-related stiffening of the central arteries, but no study addressed the management of the PP-related risk over the human lifespan.METHODS In 4,663 young (18-49 years) and 7,185 older adults (>= 50 years), brachial PP was recorded over 24 hours. Total mortality and all major cardiovascular events (MACEs) combined were coprimary endpoints. Cardiovascular death, coronary events, and stroke were secondary endpoints.RESULTS In young adults (median follow-up, 14.1 years; mean PP, 45.1 mm Hg), greater PP was not associated with absolute risk; the endpoint rates were <= 2.01 per 1,000 person-years. The adjusted hazard ratios expressed per 10-mm Hg PP increments were less than unity (P <= 0.027) for MACE (0.67; 95% confidence interval [CI], 0.47-0.96) and cardiovascular death (0.33; 95% CI, 0.11-0.75). In older adults (median follow-up, 13.1 years; mean PP, 52.7 mm Hg), the endpoint rates, expressing absolute risk, ranged from 22.5 to 45.4 per 1,000 person-years and the adjusted hazard ratios, reflecting relative risk, from 1.09 to 1.54 (P < 0.0001). The PP-related relative risks of death, MACE, and stroke decreased >3-fold from age 55 to 75 years, whereas absolute risk rose by a factor 3.CONCLUSIONS From 50 years onwards, the PP-related relative risk decreases, whereas absolute risk increases. From a lifecourse perspective, young adulthood provides a window of opportunity to manage risk factors and prevent target organ damage as forerunner of premature death and MACE. In older adults, treatment should address absolute risk, thereby extending life in years and quality.
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| 15. |
- Qin, Shuang-Jian, et al.
(författare)
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Neurotoxicity of fine and ultrafine particulate matter : a comprehensive review using a toxicity pathway-oriented adverse outcome pathway framework
- 2024
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 947
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Forskningsöversikt (refereegranskat)abstract
- Fine particulate matter (PM2.5) can cause brain damage and diseases. Of note, ultrafine particles (UFPs) with an aerodynamic diameter less than or equal to 100 nm are a growing concern. Evidence has suggested toxic effects of PM2.5 and UFPs on the brain and links to neurological diseases. However, the underlying mechanism has not yet been fully illustrated due to the variety of the study models, different endpoints, etc. The adverse outcome pathway (AOP) framework is a pathway-based approach that could systematize mechanistic knowledge to assist health risk assessment of pollutants. Here, we constructed AOPs by collecting molecular mechanisms in PM-induced neurotoxicity assessments. We chose particulate matter (PM) as a stressor in the Comparative Toxicogenomics Database (CTD) and identified the critical toxicity pathways based on Ingenuity Pathway Analysis (IPA). We found 65 studies investigating the potential mechanisms linking PM2.5 and UFPs to neurotoxicity, which contained 2, 675 genes in all. IPA analysis showed that neuroinflammation signaling and glucocorticoid receptor signaling were the common toxicity pathways. The upstream regulator analysis (URA) of PM2.5 and UFPs demonstrated that the neuroinflammation signaling was the most initially triggered upstream event. Therefore, neuroinflammation was recognized as the MIE. Strikingly, there is a clear sequence of activation of downstream signaling pathways with UFPs, but not with PM2.5. Moreover, we found that inflammation response and homeostasis imbalance were key cellular events in PM2.5 and emphasized lipid metabolism and mitochondrial dysfunction, and blood-brain barrier (BBB) impairment in UFPs. Previous AOPs, which only focused on phenotypic changes in neurotoxicity upon PM exposure, we for the first time propose AOP framework in which PM2.5 and UFPs may activate pathway cascade reactions, resulting in adverse outcomes associated with neurotoxicity. Our toxicity pathway-based approach not only advances risk assessment for PM-induced neurotoxicity but shines a spotlight on constructing AOP frameworks for new chemicals.
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| 16. |
- Song, Kai, et al.
(författare)
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An Impedance Decoupling-Based Tuning Scheme for Wireless Power Transfer System under Dual-Side Capacitance Drift
- 2021
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Ingår i: IEEE Transactions on Power Electronics. - 0885-8993 .- 1941-0107. ; 36:7, s. 7526-7536
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Tidskriftsartikel (refereegranskat)abstract
- High performance of a wireless power transfer system is related to the resonance. However, the capacitance drift caused by temperature variation leads to detuning. In this article, a tuning scheme against dual-side capacitance drift using the impedance decoupling algorithm is investigated. First, the impact of the capacitance drift on transmission efficiency and output power are analyzed. Second, it is difficult to compensate for the dual-side capacitance drift quickly since the primary and secondary sides are coupled. Therefore, the impedance decoupling algorithm is introduced. The primary and secondary reactances are decoupled from the total impedance. The two independent reactances are only determined by the capacitance drift of the corresponding side. Then, by adjusting system frequency and the phase-shift angle of the semiactive rectifier, the reactances of both sides can be eliminated, respectively. Compared with the existing tuning methods focusing on total input impedance, the continuous adjustment on two sides is avoided, so the tuning time is significantly reduced. The experimental results prove that the proposed method can improve the system efficiency by 5%-40% and reduce the tuning time by 67% under different capacitance drift.
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| 17. |
- Song, Kai, et al.
(författare)
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Constant Current Charging and Maximum System Efficiency Tracking for Wireless Charging Systems Employing Dual-Side Control
- 2020
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Ingår i: IEEE Transactions on Industry Applications. - 0093-9994 .- 1939-9367. ; 56:1, s. 622-634
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Tidskriftsartikel (refereegranskat)abstract
- Wireless power transfer (WPT) systems have attracted much attention because of their safety, convenience, and environmental friendliness. For wireless supercapacitor charging, the system efficiency and charging current are highly dependent on the load that varies over a wide range. In this article, a simultaneous maximum system efficiency (MSE) tracking and constant current (CC) charging control scheme for a supercapacitor is proposed. For CC charging, a double-sided LCC topology is chosen due to its characteristic of providing a load-independent output current. Furthermore, the impact of the coil internal resistance on the system characteristics (especially the charging current) is investigated, so a semiactive rectifier is introduced on the secondary side to achieve accurate CC charging and improve the system robustness. Based on the variable-step perturbation and observation algorithm, the MSE is tracked by searching for the minimum system input dc current using a primary-side buck converter on the premise that the charging current reaches its target value. The abovementioned two control loops are independent, and mutual communication is unnecessary when they cooperate; thus, the system is simplified. The simulation and experimental results show great consistency with the theoretical analysis. The experimental system maintains the MSE of 86% during charging the supercapacitor from 20 to 50 V with 2 A.
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| 18. |
- Wang, Gang, et al.
(författare)
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US2Mask : Image-to-mask generation learning via a conditional GAN for cardiac ultrasound image segmentation
- 2024
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Ingår i: Computers in Biology and Medicine. - Oxford : Elsevier. - 0010-4825 .- 1879-0534. ; 172, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- Cardiac ultrasound (US) image segmentation is vital for evaluating clinical indices, but it often demands a large dataset and expert annotations, resulting in high costs for deep learning algorithms. To address this, our study presents a framework utilizing artificial intelligence generation technology to produce multi-class RGB masks for cardiac US image segmentation. The proposed approach directly performs semantic segmentation of the heart's main structures in US images from various scanning modes. Additionally, we introduce a novel learning approach based on conditional generative adversarial networks (CGAN) for cardiac US image segmentation, incorporating a conditional input and paired RGB masks. Experimental results from three cardiac US image datasets with diverse scan modes demonstrate that our approach outperforms several state-of-the-art models, showcasing improvements in five commonly used segmentation metrics, with lower noise sensitivity. Source code is available at https://github.com/energy588/US2mask. © 2024 Elsevier Ltd
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| 19. |
- Xiao, Sen, et al.
(författare)
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A Study of Lumbar Disc Injury under Typical Frontal Impact Load
- 2021
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Ingår i: Journal of the Chinese Society of Mechanical Engineers, Transactions of the Chinese Institute of Engineers, Series C/Chung-Kuo Chi Hsueh Kung Cheng Hsuebo Pao. - 0257-9731. ; 42:6, s. 605-612
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Tidskriftsartikel (refereegranskat)abstract
- Although the number of seriously injured cases of frontal impact has been sharply decreased, the spine injury especially the lumber injury is still at a high level, thereby resulting in serious consequences. This paper is aimed to investigate the lumber injury mechanism in terms of the extension, compression, flexion and rotation loads during the frontal crash using the newly established lumbar model, especially to study the injury mechanism in the lumber disc on a microscale. A new detailed model for the lumbar was used, and the micro index of stress and strain was then investigated to analyze the injury mechanism of the lumber disc in the regulation frontal crash. The complex load can be divided into several representable load patterns. Four representative loads were used to reflect the loads in real accident. At last, the correlation of load types and the micro distribution was discussed to describe the injury mechanism. The results show that the disc will have the greatest stress when the loads applied on the sample. The strain in the disc is several times larger than that on the spine, which indicates the disc is the crucial part when considering the spine injury in the frontal crash. Each load poses its unique strain/stress response on the disc. The annulus fibrosus of the disc is dangerous under all loads, though the nucleus pulposus of the disc is safe during the impacts. Results in this study can provide a reference to the spine used in the study of spine cord injury.
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| 20. |
- Yang, Guang, et al.
(författare)
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Improved Interoperability Evaluation Method for Wireless Charging Systems Based on Interface Impedance
- 2021
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Ingår i: IEEE Transactions on Power Electronics. - 0885-8993 .- 1941-0107. ; 36:8, s. 8588-8592
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Tidskriftsartikel (refereegranskat)abstract
- The interoperability between the vehicle assembly (VA) and ground assembly (GA) of wireless charging systems has been specified in international standards. SAE J2954 first proposed an interoperability evaluation method based on interface impedance. However, the impedance measurement is challenging at high frequency since the phase difference between the voltage and current is not easy to measure accurately, especially when it is close to 90. Small errors in phase angle measurement are amplified in impedance calculation due to the sine/cosine function. This letter proposes an impedance measurement method using the power decomposition algorithm. By decomposing the input power into two orthogonal components, the impedance angle can be calculated without directly measuring the phase difference between the voltage and current. Thus, the measurement results of the impedance angle do not introduce errors. With the proposal, the high-cost probe or complex high-precision phase difference measurement circuit is not needed. The experimental results show that the conventional methods maximum relative error reaches 80%, making interoperability hard to determine. Reversely, with the proposed method, the relative error of impedance measurement is reduced to less than 10%.
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