Deep Learning Image Reconstruction for Transcatheter Aortic Valve Implantation Planning: Image Quality, Diagnostic Performance, Contrast volume and Radiation Dose Assessment.

RATIONALE AND OBJECTIVES: To assess image quality, contrast volume and radiation dose reduction potential and diagnostic performance with the use of high-strength deep learning image reconstruction (DLIR-H) in transcatheter aortic valve implantation (TAVI) planning CT. METHODS: We prospectively enrolled 128 patients referred to TAVI-planning CT. Patients were randomly divided into two groups: DLIR-H group (n = 64) and conventional group (n = 64). The DLIR-H group was scanned with tube voltage of 80kVp and body weighted-dependent contrast injection rate of 28mgI/kg/s, images reconstructed using DLIR-H; the conventional group was scanned with 100kVp and contrast injection rate of 40mgI/kg/s, and images reconstructed using adaptive statistical iterative reconstruction-V at 50% (ASIR-V 50%). Radiation dose, contrast volume, contrast injection rate, and image quality were compared between the two groups. The diagnostic performance of TAVI planning CT for coronary stenosis in 115 patients were calculated using invasive coronary angiography as golden standard. RESULTS: DLIR-H group significantly reduced radiation dose (4.94 ± 0.39mSv vs. 7.93 ± 1.20mSv, p < 0.001), contrast dose (45.28 ± 5.38 mL vs. 63.26 ± 9.88 mL, p < 0.001), and contrast injection rate (3.1 ± 0.31 mL/s vs. 4.9 ± 0.2 mL/s, p < 0.001) compared to the conventional group. Images in DLIR-H group had significantly higher SNR and CNR (all p < 0.001). For the diagnostic performance on a per-patient basis, TAVI planning CT in the DLIR-H group provided 100% sensitivity, 92.1% specificity, 100% negative predictive value (NPV), and 84.2% positive predictive value for the detection of > 50% stenosis. In the conventional group, the corresponding results were 94.7%, 95.3%, 97.6%, and 90.0%, respectively. CONCLUSION: DLIR-H in TAVI-planning CT provides improved image quality with reduced radiation and contrast doses, and enables satisfactory diagnostic performance for coronary arteries stenosis.

Unravelling crystal growth of nanoparticles.

Crystal growth from nanoscale constituents is a ubiquitous phenomenon in biology, geology and materials science. Numerous studies have focused on understanding the onset of nucleation and on producing high-quality crystals by empirically sampling constituents with different attributes and varying the growth conditions. However, the kinetics of post-nucleation growth processes, an important determinant of crystal morphology and properties, have remained underexplored due to experimental challenges associated with real-space imaging at the nanoscale. Here we report the imaging of the crystal growth of nanoparticles of different shapes using liquid-phase transmission electron microscopy, resolving both lateral and perpendicular growth of crystal layers by tracking individual nanoparticles. We observe that these nanoscale systems exhibit layer-by-layer growth, typical of atomic crystallization, as well as rough growth prevalent in colloidal systems. Surprisingly, the lateral and perpendicular growth modes can be independently controlled, resulting in two mixed crystallization modes that, until now, have received only scant attention. Combining analytical considerations with molecular dynamics and kinetic Monte Carlo simulations, we develop a comprehensive framework for our observations, which are fundamentally determined by the size and shape of the building blocks. These insights unify the understanding of crystal growth across four orders of magnitude in particle size and suggest novel pathways to crystal engineering.

Health risk assessment of cadmium exposure by integration of an in silico physiologically based toxicokinetic model and in vitro tests.

Cadmium (Cd) is a common environmental pollutant that can damage multiple organs, including the kidney. To prevent renal effects, international authorities have set health-based guidance values of Cd from epidemiological studies. To explore the health risk of Cd exposure and whether human equivalent doses (HEDs) derived from in vitro tests match the current guidance values, we integrated renal tubular epithelial cell-based assays with a physiologically based toxicokinetic model combined with the Monte Carlo method. For females, the HEDs (µg/kg/week) derived from KE2 (DNA damage), KE3 (cell cycle arrest), and KE4 (apoptosis) were 0.20 (2.5th-97.5th percentiles: 0.09-0.48), 0.52 (0.24-1.26), and 2.73 (1.27-6.57), respectively; for males the respective HEDs were 0.23 (0.10-0.49), 0.60 (0.27-1.30), and 3.11 (1.39-6.78). Among them, HEDKE4 (female) was close to the tolerable weekly intake (2.5 µg/kg/week) set by the European Food Safety Authority. The margin of exposure (MOE) derived from HEDKE4 (female) indicated that risks of renal toxicity for populations living in cadmium-contaminated regions should be of concern. This study provided a new approach methodology (NAM) for environmental chemical risk assessment using in silico and in vitro methods.

Assessment of intestinal injury of hexavalent chromium using a modified in vitro gastrointestinal digestion model.

Intestinal injury assessment of hexavalent chromium (Cr-VI) in humans is crucial for quantifying assessment of adverse health risk posed by the intake of Cr (VI)-contaminated water. To overcome the deficiency in simulating human gastric reduction and intestinal absorption, we modified the constituents of simulated gastric fluid in in vitro digestion method by adding reductants glutathione (18 µM) and ascorbic acid (180 µM), which incorporated with human intestinal epithelial model to construct an in vitro gastrointestinal digestion (IVGD) model for intestinal injury assessment. Cr-VI bioaccessibility results from IVGD model showed that weak gastric acidity significantly increased the intestinal accessible Cr-VI dose by 22.41-38.43 folds. The time-course intestinal absorption indicated prolongation of intestinal exposure destroyed the intestinal epithelium, and 24 h after Cr-VI treatment was a good time point to perform intestinal absorption and toxicity assessment. A series of cell-based bioassays provided initial warning of adverse effect, suggesting that epithelial integrity exhibited greatest sensitivity to Cr-VI exposure and might be used as a sensitive marker for the toxicity assessment of oral exposure to Cr-VI. Notably, this study provides a feasible strategy for delineation of Cr-VI biotransformation and intestinal injury following ingestion exposure, which contributes to address the toxicity data gap of low-dose exposure in humans and puts forward a reference for intestinal toxicity assessment of other chemicals.

Systematic Analysis of the Global, Regional and National Burden of Cardiovascular Diseases from 1990 to 2017.

BACKGROUND: Previous studies on the burden of cardiovascular diseases (CVDs) were mainly based on limited data of the study period or area, or did not include detailed risk factor analysis. OBJECTIVE: To investigate up-to-date temporal and regional trends and risk factors of mortality and disability-adjusted life years (DALYs) attributed to CVDs by age, sex, and disease throughout the world. METHODS: Data for the disease burden of CVDs in 195 countries and territories from 1990 to 2017, including mortality, DALYs, age-standardized mortality rates, and age-standardized DALY rates, were estimated from the Global Burden of Disease Study 2017. Risk factors attributable to deaths and DALYs for CVDs were also estimated using the comparative risk assessment framework. RESULTS: The number of deaths from CVDs increased by 48.62%, from 11.94 (95% UI 11.78-12.18) million in 1990 to 17.79 (17.53-18.04) million in 2017. However, the age-standardized mortality rate decreased by an average of - 1.45% (- 1.72% to - 1.18%) annually. After fluctuation in the expected age-standardized mortality rate of CVDs in most of the socio-demographic index (SDI) scale, these rates decrease rapidly for SDI values of 0.7 and higher. In 2017, metabolic risks accounted for 73.48% of deaths and 73.25% of DALYs due to CVDs, behavioral factors accounted for 63.23% of deaths and 66.71% of attributable DALYs. CONCLUSION: CVDs remain a major global health burden due to the increment in death numbers and DALYs. Aging and the main risk factors are the main drivers of mortality and health loss. More attention to main risk factors should be paid with supportive health policies.

An Empirical Study on Hazardous Chemicals Risk of Urban Residents in China: Analysis of Mediating Effect and Channel Preference of Response Action Decision Model.

Because urban residents do not have a strong understanding of hazardous chemicals, they cannot effectively make response action decisions to ensure safety, protect lives, and reduce property damage. This paper constructs the Response Action Decision Model of hazardous chemicals, and analyzes the mediating effect of Information Processing and Threat Perception, as well as channel preferences of urban residents with different demographic characteristics. A total of 1700 questionnaires were collected in Chongqing, Tianjin, Fujian Zhangzhou, Shandong Zibo and Lanzhou, where there are significant hazardous chemicals factories. The results show that: Firstly, Information Processing and Threat Perception have significant mediating effects on the relationship between Mass Media, Social Media, Face-to-face communication and Response Action Decision in a single channel, which can effectively promote the spread effect of different channels, affecting the ways that urban residents make hazard response action decisions; secondly, Information Processing and Threat Perception do not have a mediating effect on the relationship between the channel combination of "Mass Media ↔ Social Media", "Mass Media ↔ Face-to-face communication", "Social Media ↔ Face-to-face communication" and Response Action Decision, and the channel combination can directly link to the Response Action Decision; thirdly, in terms of the extent that it affects urban residents to make response action decisions, Mass Media is greater than Social Media and greater than Face-to-face communication; fourthly, two demographic characteristics of gender and experience have a stronger moderating effect for the Mass Media channel, while other demographic characteristics have greater influences on the Response Action Decision Model; finally, the Response Action Decision Model can be better applied to those analyses and research which address threat perception of hazardous chemicals and response action decisions of urban residents in China.

Jointed Synchronous Photocatalytic Oxidation and Chromate Reduction Enabled by the Defect Distribution upon BiVO4: Mechanism Insight and Toxicity Assessment.

Exploring active and ecological materials for the restoration of complex pollution system is highly desired. This study presents a facile defect-tailoring strategy for combined pollutants purification with BiVO4 photocatalysis in which the jointed synchronous reaction of oxidation and reduction is integrated instead of the sequential reaction in two individual systems. XPS and EPR reveal that BiVO4 with a suitable oxygen vacancies (OVs) concentration and distribution exhibits superior photocatalytic activity under the coexistence of TC-HCl and Cr(VI) with Cr(VI) reduction efficiency increased by 71 times compared with the individual Cr(VI) system along with TC-HCl removal efficiency comparable to a single TC-HCl system. The mechanism of synchronous redox reactions mediated by surface OVs is revealed by comprehensive characterization together with reaction kinetic analysis, and the electronic band structure adjustment induced by the OVs variation is confirmed. Active species identification tests and intermediate product analysis confirm that singlet oxygen (1O2) accounts for the selective oxidation of TC-HCl, while electrons dominate the reduction of Cr(VI), under a coexistent environment. The influence of water quality parameters (e.g., pH, cations, anions, and organic substances) on the photocatalytic activity is investigated considering the complexity of the real aquatic environment. Importantly, toxicity assessment with Gram-negative strain E. coli as a model bacterium validates that the toxicity of the intermediates can be reduced to low or even ultralow levels. This work is dedicated to the mechanistic study of defect photocatalysis over BiVO4 and provides a jointed synchronous reaction system for combined pollutant purification.

Content and Dietary Exposure Assessment of Toxic Elements in Infant Formulas from the Chinese Market.

In this study, the content of chromium (Cr), arsenic (As), cadmium (Cd) and lead (Pb) in domestic and imported infant formulas from Beijing, China were analyzed using inductively coupled plasma mass spectrometry. The content of Cr, As, Cd and Pb was 2.51-83.80, 0.89-7.87, 0.13-3.58 and 0.36-5.57 µg/kg, respectively. Even though there were no significant differences in toxic elements content between domestic and imported infant formulas, Cd content was slightly lower in domestic samples. The estimated daily intake (EDI), target hazard quotient (THQ) and hazard index (HI) were calculated for infants between 0.5 and 5 y of age. The EDIs were lower than the oral reference doses. THQ of As, Cr, Cd and Pb was 0.027-0.103, 0.024-0.093, 0.0025-0.0090 and 0.0015-0.0046, respectively. HI values were 0.055-0.192 for boys and 0.056-0.209 for girls and were inversely associated with age with a threshold < 1. The non-carcinogenic risk value were in the safe range, indicating that exposure of As, Pb, Cr and Cd from infant formulas do not represent a health risk in China.