Association of stress hyperglycemia ratio with left ventricular function and microvascular obstruction in patients with ST-segment elevation myocardial infarction: a 3.0 T cardiac magnetic resonance study.

BACKGROUND: Stress hyperglycemia, which is associated with poor prognosis in patients with acute myocardial infarction (AMI), can be determined using the stress hyperglycemia ratio (SHR). Impaired left ventricular function and microvascular obstruction (MVO) diagnosed using cardiac magnetic resonance (CMR) have also been proven to be linked to poor prognosis in patients with AMI and aid in risk stratification. However, there have been no studies on the correlation between fasting SHR and left ventricular function and MVO in patients with acute ST-segment elevation myocardial infarction (ASTEMI). Therefore, this study aimed to investigate the additive effect of fasting SHR on left ventricular function and global deformation in patients with ASTEMI and to explore the association between fasting SHR and MVO. METHODS: Consecutive patients who underwent CMR at index admission (3-7 days) after primary percutaneous coronary intervention (PPCI) were enrolled in this study. Basic clinical, biochemical, and CMR data were obtained and compared among all patients grouped by fasting SHR tertiles: SHR1: SHR < 0.85; SHR2: 0.85 ≤ SHR < 1.01; and SHR3: SHR ≥ 1.01. Spearman's rho (r) was used to assess the relationship between fasting SHR and left ventricular function, myocardial strain, and the extent of MVO. Multivariable linear regression analysis was performed to evaluate the determinants of left ventricular function and myocardial strain impairment in all patients with AMI. Univariable and multivariable regression analyses were performed to investigate the correlation between fasting SHR and the presence and extent of MVO in patients with AMI and those with AMI and diabetes mellitus (DM). RESULTS: A total of 357 patients with ASTEMI were enrolled in this study. Left ventricular ejection fraction (LVEF) and left ventricular global function index (LVGFI) were significantly lower in SHR2 and SHR3 than in SHR1. Compared with SHR1 and SHR2 groups, left ventricular strain was lower in SHR3, as evidenced by global radial (GRS), global circumferential (GCS), and global longitudinal (GLS) strains. Fasting SHR were negatively correlated with LVEF, LVGFI, and GRS (r = - 0.252; r = - 0.261; and r = - 0.245; all P<0.001) and positively correlated with GCS (r = 0.221) and GLS (r = 0.249; all P <0.001). Multivariable linear regression analysis showed that fasting SHR was an independent determinant of impaired LVEF, LVGFI, GRS, and GLS. Furthermore, multivariable regression analysis after adjusting for covariates signified that fasting SHR was associated with the presence and extent of MVO in patients with AMI and those with AMI and DM. CONCLUSION: Fasting SHR in patients with ASTEMI successfully treated using PPCI is independently associated with impaired cardiac function and MVO. In patients with AMI and DM, fasting SHR is an independent determinant of the presence and extent of MVO.

Incremental Prognostic Value of Left Atrial Strain in Patients With Suspected Myocarditis and Preserved Left Ventricular Ejection Fraction.

BACKGROUND: Analysis of left atrial (LA) strain and left atrioventricular coupling index (LACI) have prognostic value in cardiovascular diseases. However, the prognostic value of LA strain and LACI in patients with suspected myocarditis and preserved left ventricular ejection fraction (LVEF) is unclear. PURPOSE: To investigate the prognostic value of LA strain and LACI in patients with suspected myocarditis and preserved LVEF in comparison with conventional MRI outcome predictors. STUDY TYPE: Retrospective. POPULATION: One hundred sixty-five patients with clinically suspected myocarditis and preserved LVEF with available follow-up data. FIELD STRENGTH/SEQUENCE: Steady-state free precession cine and phase-sensitive inversion recovery segmented gradient echo late gadolinium enhancement sequences at 3.0 T. ASSESSMENT: Left ventricular (LV) and LA strain were evaluated using feature tracking. LACI was calculated as the ratio of LA and LV volumes at LV end-diastole. Patients were followed-up with the primary endpoint being major adverse cardiovascular events (MACE). STATISTICAL TESTS: Independent-samples t-test and Mann-Whitney U test to compare patients with and without MACE, receiver operating characteristic (ROC) curve analysis to define high/low risk groups, Kaplan-Meier survival analysis and Cox proportional hazards regression to assess prognosis. A P value of <0.05 was considered statistically significant. RESULTS: The associations of LV strain parameters (including global radial, circumferential, and longitudinal strain) and LACI with MACE were not significant (P = 0.511, 0.108, 0.148, and 0.847, respectively). An optimal LA conduit strain (Ԑe) cutoff value of 10.4% was identified to best classify patients into low- and high-risk groups. Only Ԑe was significantly associated with MACE in both univariable (hazards ratio [HR] 0.936, 95% confidence interval [CI] 0.884-0.991) and multivariable Cox survival analyses (HR 0.937, 95% CI 0.884-0.994). DATA CONCLUSION: LA conduit strain has prognostic value in patients with suspected myocarditis and preserved LVEF, incremental to conventional MRI outcome predictors, whereas LACI was not associated with MACE occurrence. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

Prognostic Value of Left Ventricular Longitudinal Function and Myocardial Fibrosis in Patients With Ischemic and Non-Ischemic Dilated Cardiomyopathy Concomitant With Type 2 Diabetes Mellitus: A 3.0 T Cardiac MR Study.

BACKGROUND: Poorly controlled type 2 diabetes mellitus (T2DM) is known to result in left ventricular (LV) dysfunction, myocardial fibrosis, and ischemic/nonischemic dilated cardiomyopathy (ICM/NIDCM). However, less is known about the prognostic value of T2DM on LV longitudinal function and late gadolinium enhancement (LGE) assessed with cardiac MRI in ICM/NIDCM patients. PURPOSE: To measure LV longitudinal function and myocardial scar in ICM/NIDCM patients with T2DM and to determine their prognostic values. STUDY TYPE: Retrospective cohort. POPULATION: Two hundred thirty-five ICM/NIDCM patients (158 with T2DM and 77 without T2DM). FIELD STRENGTH/SEQUENCE: 3T; steady-state free precession cine; phase-sensitive inversion recovery segmented gradient echo LGE sequences. ASSESSMENT: Global peak longitudinal systolic strain rate (GLPSSR) was evaluated to LV longitudinal function with feature tracking. The predictive value of GLPSSR was determined with ROC curve. Glycated hemoglobin (HbA1c) was measured. The primary adverse cardiovascular endpoint was follow up every 3 months. STATISTICAL TESTS: Mann-Whitney U test or student's t-test; Intra and inter-observer variabilities; Kaplan-Meier method; Cox proportional hazards analysis (threshold = 5%). RESULTS: ICM/NIDCM patients with T2DM exhibited significantly lower absolute value of GLPSSR (0.39 ± 0.14 vs. 0.49 ± 0.18) and higher proportion of LGE positive (+) despite similar LV ejection fraction, compared to without T2DM. LV GLPSSR was able to predict primary endpoint (AUC 0.73) and optimal cutoff point was 0.4. ICM/NIDCM patients with T2DM (GLPSSR < 0.4) had more markedly impaired survival. Importantly, this group (GLPSSR < 0.4, HbA1c ≥ 7.8%, or LGE (+)) exhibited the worst survival. In multivariate analysis, GLPSSR, HbA1c, and LGE (+) significantly predicted primary adverse cardiovascular endpoint in overall ICM/NIDCM and ICM/NIDCM patients with T2DM. CONCLUSIONS: T2DM has an additive deleterious effect on LV longitudinal function and myocardial fibrosis in ICM/NIDCM patients. Combining GLPSSR, HbA1c, and LGE could be promising markers in predicting outcomes in ICM/NIDCM patients with T2DM. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: 5.

Using design thinking to create and implement a 3D digital library of anatomical specimens.

Design thinking (DT) is a five-stage process (empathize, define, ideate, prototype, and test) that guides the creation of user-centered solutions to complex problems. DT is in common use outside of science but has rarely been applied to anatomical education. The use of DT in this study identified the need for flexible access to anatomical specimens outside of the anatomy laboratory and guided the creation of a digital library of three-dimensional (3D) anatomical specimens (3D Anatomy Viewer). To test whether the resource was fit for purpose, a mixed-methods student evaluation was undertaken. Student surveys (n = 46) were employed using the system usability scale (SUS) and an unvalidated acceptability questionnaire. These verified that 3D Anatomy Viewer was usable (SUS of 72%) and acceptable (agreement range of 77%-93% on all Likert-type survey statements, Cronbach's alpha = 0.929). Supplementary interviews (n = 5) were analyzed through content analysis and revealed three main themes: (1) a credible online supplementary learning resource; (2) learning anatomy with 3D realism and interactivity; (3) user recommendations for expanding the number of anatomical models, test questions, and gamification elements. These data demonstrate that a DT framework can be successfully applied to anatomical education for creation of a practical learning resource. Anatomy educators should consider employing a DT framework where student-centered solutions to learner needs are required.

TLR4 in POMC neurons regulates thermogenesis in a sex-dependent manner.

The rising prevalence of obesity has become a worldwide health concern. Obesity usually occurs when there is an imbalance between energy intake and energy expenditure. However, energy expenditure consists of several components, including metabolism, physical activity, and thermogenesis. Toll-like receptor 4 (TLR4) is a transmembrane pattern recognition receptor, and it is abundantly expressed in the brain. Here, we showed that pro-opiomelanocortin (POMC)-specific deficiency of TLR4 directly modulates brown adipose tissue thermogenesis and lipid homeostasis in a sex-dependent manner. Deleting TLR4 in POMC neurons is sufficient to increase energy expenditure and thermogenesis resulting in reduced body weight in male mice. POMC neuron is a subpopulation of tyrosine hydroxylase neurons and projects into brown adipose tissue, which regulates the activity of sympathetic nervous system and contributes to thermogenesis in POMC-TLR4-KO male mice. By contrast, deleting TLR4 in POMC neurons decreases energy expenditure and increases body weight in female mice, which affects lipolysis of white adipose tissue (WAT). Mechanistically, TLR4 KO decreases the expression of the adipose triglyceride lipase and lipolytic enzyme hormone-sensitive lipase in WAT in female mice. Furthermore, the function of immune-related signaling pathway in WAT is inhibited because of obesity, which exacerbates the development of obesity reversely. Together, these results demonstrate that TLR4 in POMC neurons regulates thermogenesis and lipid balance in a sex-dependent manner.

A workflow for the creation of photorealistic 3D cadaveric models using photogrammetry.

Three-dimensional (3D) representations of anatomical specimens are increasingly used as learning resources. Photogrammetry is a well-established technique that can be used to generate 3D models and has only been recently applied to produce visualisations of cadaveric specimens. This study has developed a semi-standardised photogrammetry workflow to produce photorealistic models of human specimens. Eight specimens, each with unique anatomical characteristics, were successfully digitised into interactive 3D models using the described workflow and the strengths and limitations of the technique are described. Various tissue types were reconstructed with apparent preservation of geometry and texture which visually resembled the original specimen. Using this workflow, an institution could digitise their existing cadaveric resources, facilitating the delivery of novel educational experiences.

Right Ventricular Function in Takayasu's Arteritis Patients With Pulmonary Artery Involvement Using MRI Feature Tracking.

BACKGROUND: Pulmonary artery involvement (PAI) is not rare in Takayasu arteritis (TA). Persistently elevated pulmonary arterial pressure in TA-PAI patients leads to pulmonary hypertension (PH), and eventually cardiac death. Thus, the early detection of right ventricular dysfunction before the onset of PH is important. PURPOSE: To explore the potential of right ventricular global peak longitudinal and circumferential strain (RVGLS and RVGCS, respectively) in detecting right ventricular myocardial damage in TA-PAI patients without PH. STUDY TYPE: Retrospective. POPULATION: One hundred and six TA patients (39.6 ± 13.9 years), of whom 52 were non-PAI and 54 were PAI patients (36 without PH and 18 with PH), along with 58 sex- and age-matched healthy volunteers (HVs) (36.7 ± 13.2 years). The involved arteries were validated by aorta magnetic resonance (MR) angiography and pulmonary artery computed tomography angiography. FIELD STRENGTH/SEQUENCE: 3 T/Cine imaging sequence with a steady-state free precession readout. ASSESSMENT: Cardiac MRI-derived parameters measured by two radiologists independently were compared among HVs, and TA patients with and without PAI. In addition, these indices were further compared among HVs, and TA-PAI patients with and without PH. STATISTICAL TESTS: Student's t test, one-way ANOVA analysis, Pearson and Spearman correlation analysis, and reproducibility analysis. A P-value of <0.05 was considered statistically significant. RESULTS: Although the TA-PAI patients without PH had a similar RV ejection fraction (RVEF) with HV (P = 0.348), RVGLS (non-PH 20.6 ± 3.7% vs. HV 24.0 ± 3.1%) was significantly lower and RVGCS (non-PH 14.8 ± 3.9% vs. HV 13.0 ± 2.7%) higher. The TA-PAI patients with PH had significantly poorer RVGLS (PH 13.5 ± 3.8% vs. non-PH 20.6 ± 3.7%) and RVGCS (PH 10.9 ± 3.2% vs. non-PH 14.8 ± 3.9%) than those without PH. DATA CONCLUSION: Right ventricular dysfunction was detected in the TA-PAI patients without PH. MR-feature tracking may be an effective method for detecting early cardiac damage in the TA-PAI patients without PH. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 3.

Microenvironment Modulation of Single-Atom Ru in ZrSBA-15 for CO2 Hydrogenation to Formic Acid.

The chemical microenvironment modulation of active sites holds promise for facilitating their catalytic performance. Herein, single-atom Ru anchored by ZrSBA-15 modified with diverse organic amine groups has been fabricated and enabled CO2 hydrogenation to produce formic acid (FA) under mild conditions. However, the reaction cannot be achieved without the modification of organic amines. The functional groups as the microenvironment around Ru active sites effectively regulated the activity, in which Ru encapsulated in ZrSBA-15 bearing -NH2 groups exhibited the highest activity, with turnover number (TON) and turnover frequency (TOF) values of 505 and 64 h-1, respectively. Both characterization and experimental results validated that the functional group manipulated the adsorption capacity of the reactant, the electronic state of Ru and hydrophilicity/hydrophobicity of the materials, and thus the catalytic performance.

Synergistic Enhancement of Photocatalytic H2 Evolution over NH2-MIL-125 Modified with Dual Cocatalyst.

The construction of efficient photocatalysts for water splitting to enable H2 evolution is pivotal to alleviate energy issues and environmental concerns. In this work, carbon dots (CDs) were prepared by employing "green solvent" ionic liquids as carbon sources and then combined with Pt/NH2-MIL-125, resulting in the emergence of a high-efficiency photocatalyst termed CDs-Pt/NH2-MIL-125 for the first time. This composite photocatalyst exhibited outstanding photocatalytic activity in H2 production under visible light irradiation. Notably, the H2 production rate of CDs100-Pt/NH2-MIL-125 reaches up to 951.4 µmol/g/h, which was 3.1 times that of Pt/NH2-MIL-125. The characterization results indicate that CDs and Pt uniformly dispersed on the surface of NH2-MIL-125 and fabricated a synergistic compact structure, providing a high BET surface area (985 m2 g-1) and a suitable band gap. Furthermore, the distinctive embeddable-dispersed CDs and Pt, as dual cocatalyst, can harvest light and facilitate the transfer of photogenerated electrons, thereby significantly augmenting the exploitation of visible light. The plausible mechanism of photocatalytic H2 evolution over the CDs-Pt/NH2-MIL-125 catalyst was also discussed. This work introduces a promising strategy for designing high-performance CDs-MOFs-based photocatalysts, an innovative step toward achieving efficient photocatalytic water splitting for H2 production.

Three-dimensional printing, holograms, computational modelling, and artificial intelligence for adult congenital heart disease care: an exciting future.

Congenital heart disease (CHD) is often comprised of complex three-dimensional (3D) anatomy that must be well understood to assess the pathophysiological consequences and guide therapy. Thus, detailed cardiac imaging for early detection and planning of interventional and/or surgical treatment is paramount. Advanced technologies have revolutionized diagnostic and therapeutic practice in CHD, thus playing an increasing role in its management. Traditional reliance on standard imaging modalities including echocardiography, cardiac computed tomography (CT) and magnetic resonance imaging (MRI) has been augmented by the use of recent technologies such as 3D printing, virtual reality, augmented reality, computational modelling, and artificial intelligence because of insufficient information available with these standard imaging techniques. This has created potential opportunities of incorporating these technologies into routine clinical practice to achieve the best outcomes through delivery of personalized medicine. In this review, we provide an overview of these evolving technologies and a new approach enabling physicians to better understand their real-world application in adult CHD as a prelude to clinical workflow implementation.

Corticotropin-releasing factor receptor type 2 in the midbrain critically contributes to the hedonic feeding behavior of mice under heat stress.

Heat stress is an important factor that affects food intake. Previous studies have proven that heat stress can regulate feeding behavior through a homeostasis pathway and decrease appetite in animals and humans. However, the relationship between heat stress and midbrain reward regulation has not been reported. Corticotropin-releasing factor receptor type 2 (CRFR2) is the receptor of corticotropin-releasing factor (CRF), which is the key hypothalamic pituitary adrenal axis (HPA axis) regulating the stress response. In our study, the effects of heat stress on hedonic feeding behavior were investigated. The results showed that heat stress can affect hedonic feeding behavior and decrease high-fat diet (HFD) intake. Furthermore, the mRNA expression of tyrosine hydroxylase in the VTA decreased under heat stress compared with that at 25 °C. Meanwhile, intraventricular injection of a CRFR2 antagonist reversed the decrease in HFD intake and conditional place preference (CPP) caused by heat stress. In conclusion, CRFR2 in the midbrain plays an important role in the decrease in hedonic feeding behavior caused by heat stress.

The role of 3D printed heart models in immediate and long-term knowledge acquisition in medical education.

BACKGROUND: The long-term effect of three-dimensional printed heart model (3DPHM) on knowledge acquisition of congenital heart disease (CHD) remains unknown. This prospective cohort study aims to investigate the role of 3DPHM in improving immediate knowledge gain and long-term knowledge retention on CHD among the medical students. METHODS: Fifty-three second and third year medical students were assigned into two groups to compare their immediate knowledge acquisition and knowledge retention after an education session on anatomy and pathophysiology of CHD. During the 1.5 hour-long education session, both the control (n = 25) and study groups (n = 28) had access to identical teaching materials: digital 3D heart models, 2D diagrams, and medical images, except for 3DPHM which were only used in the study group. The immediate knowledge gain was assessed via an online quiz, whereas the long-term knowledge retention was assessed using another quiz in 6-weeks' time post-intervention. A survey was also conducted to evaluate the participants' learning experience. RESULTS: There is no significant difference in the immediate knowledge acquisition and long-term knowledge retention between the groups (U = 272, p = 0.16 and r = -0.143, p = 0.15 respectively). Majority of the students (96% in control group and 85% in 3DPHM group) responded that the 3DPHM would have/had improved their learning experience. Despite that, there is no significant difference in the self-perceived knowledge improvement between the groups. CONCLUSIONS: This study concludes that the 3DPHM do not significantly improve both immediate knowledge acquisition and knowledge retention among the medical students. However, further research with larger sample size, as well as categorizing the type of questions in the quiz, is needed to better assess the role of 3DPHM in different educational components.

Comparison of Different Thoracic Aortic Wall Characteristics for Assessment of Disease Activity in Takayasu Arteritis: A Quantitative Study with 3.0 T Magnetic Resonance Imaging.

BACKGROUND: Determination of disease activity in Takayasu arteritis (TAK) is crucial for clinical management but challenging. The value of different magnetic resonance imaging (MRI) characteristics for the assessment of disease activity remains unclear. This study investigated the imaging findings of the thoracic aortic wall and elasticity by using a comprehensive 3.0 T MRI protocol. METHODS: We prospectively enrolled 52 consecutive TAK patients. TAK activity was recorded according to the ITAS2010. All the patients underwent thoracic aortic MRI. The luminal morphology of the thoracic aorta and its main branches were quantitatively evaluated using a contrast-enhanced magnetic resonance angiography (MRA) sequence. The maximum wall thickness of the thoracic aorta, postcontrast enhancement ratio, and aortic wall edema were analyzed in each patient through pre- and post-enhanced T1-weighted and T2-weighted imaging. Pulse-wave velocity (PWV) of the thoracic aorta was calculated using a four-dimensional flow technique. RESULTS: The majority of the 52 patients had type V disease (34.62%, 18/52). Among all the MRI indicators of the thoracic aorta, the area under the curve was the largest for the maximal wall thickness (0.804, 95% confidence interval [CI] = 0.667-0.941). The maximal wall thickness (93.33%, 95% CI = 68.1%-99.8%) exhibited the highest sensitivity with a cutoff value of 3.12 mm. Wall edema (84.00%, 95% CI = 63.9%-95.5%) presented the highest specificity. A positive correlation was noted between PWV and patients' age (r = 0.54, p < 0.001), disease duration (r = 0.52, p < 0.001), and the maximum wall thickness (r = 0.45, p = 0.001). CONCLUSIONS: MRI enabled the comprehensive assessment of aortic wall morphology and functional markers for TAK disease activity. Aortic maximal wall thickness was the most accurate indicator of TAK activity. The early phase was superior to the delay phase for aortic wall enhancement analysis for assessing TAK activity.

Diagnostic and Prognostic Value of Cardiac Magnetic Resonance Strain in Suspected Myocarditis With Preserved LV-EF: A Comparison Between Patients With Negative and Positive Late Gadolinium Enhancement Findings.

BACKGROUND: Late gadolinium enhancement (LGE) is absent in many patients with suspected myocarditis and preserved left ventricular ejection fraction (LV-EF), which poses difficulties in diagnosis and risk stratification. PURPOSE: To investigate the diagnostic and prognostic value of ventricular myocardial strain in patients with suspected myocarditis, preserved LV-EF, and negative Lake Louis Criteria (LLC) by comparing the findings in LGE negative and LGE positive patients. STUDY TYPE: Retrospective. POPULATION: A total of 108 patients with clinically suspected myocarditis who did not satisfy LLC were divided into LGE negative (N = 65) and LGE positive (N = 43) groups. A control group consisted of 50 healthy volunteers. FIELD STRENGTH/SEQUENCE: Steady-state free precession cine and phase-sensitive inversion recovery segmented gradient echo LGE sequences at 3.0 T. ASSESSMENT: Myocardial strain of the ventricles was evaluated by feature tracking, major adverse cardiovascular events (MACE) were assessed during follow-up since the date of magnetic resonance examination. STATISTICAL TESTS: Independent-samples t test, Mann-Whitney U test, receiver operating characteristic curve analysis, and Cox proportional hazard regression were performed. A P-value <0.05 was considered statistically significant. RESULTS: Cardiac function and myocardial deformability were impaired in all patients relative to controls. Left ventricular-global radial (LV-GRS), circumferential (LV-GCS), and longitudinal (LV-GLS) strain had diagnostic value, even in LGE negative patients (sensitivity = 0.446, 0.523, and 0.662; specificity = 0.92, 0.80, and 0.64; AUC = 0.685, 0.675, and 0.648, respectively). After a median follow-up of 530.5 (interquartile range: 168.5-969.25) days, MACE occurred in 18 (16.67%) patients. Right ventricular GLS showed prognostic value in all patients and in LGE negative patients, both in univariable analysis (hazard ratio [HR] 1.049, 95% confidence interval [CI] 1.001-1.099 and HR 1.068, 95% CI 1.011-1.127, respectively) and in multivariable Cox survival analysis. LV-GLS was associated with MACE in LGE positive patients in multivariable Cox survival analysis. DATA CONCLUSION: Myocardial strain provides diagnostic and prognostic value in suspected myocarditis with preserved LV-EF, even in the absence of LGE. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: 2.

Assessment of Image Quality of Coronary Computed Tomography Angiography in Obese Patients by Comparing Deep Learning Image Reconstruction With Adaptive Statistical Iterative Reconstruction Veo.

OBJECTIVE: The aim of the study was to evaluate the image quality of coronary computed tomography (CT) angiography (CCTA) in obese patients by using deep learning image reconstruction (DLIR) in comparison with adaptive statistical iterative reconstruction Veo (ASiR-V). METHODS: We prospectively evaluated 60 obese patients (body mass index [BMI] ≥ 30 kg/m2) who underwent coronary CT angiography in a single center. All CT scans were performed with GE Revolution 256-row CT at 120 kV (group A; 20 men, 10 women; mean age = 54.3 years; mean BMI = 33.4 kg/m2) or 100 kV (group B; 18 men; 12 women; mean age = 56.8 years; mean BMI = 32.9 kg/m2). Images in group A were reconstructed using ASiR-V, whereas images in group B were reconstructed using ASiR-V, DLIR-medium (DLIR-M), and DLIR-high (DLIR-H). Three blinded independent readers assessed the subjective image quality and measured the objective image quality. Radiation dose estimates were calculated and compared between patients by using 0.014 and 0.026 mSv·mGy-1 cm-1 corresponding to chest and heart conversion coefficients, respectively. RESULTS: The subjective score was significantly higher for images reconstructed using 120-kV ASiR-V (3.8), DLIR-M (3.9), and DLIR-H (4.0) compared with those reconstructed using 100-kV ASiR-V (3.5). Image noise was significantly lower in images reconstructed using DLIR-H compared with those reconstructed using other reconstruction algorithm (P < 0.001, respectively). The contrast-to-noise ratio was significantly higher in the DLIR-H group than in the groups using other reconstruction algorithm (P < 0.001). The effective radiation dose was significantly lower in group B than in group A (P < 0.001). CONCLUSIONS: Compared with ASiR-V, DLIR improved image quality in obese individuals without comprising image quality or increasing the radiation dose.

Impact of Sublingual Nitroglycerin on the Assessment of Computed Tomography-derived Fractional Flow Reserve: An Intraindividual Comparison Study.

OBJECTIVE: The aim of this study was to investigate the impact of nitroglycerin (NTG) on the assessment of computed tomography-derived fractional flow reserve (CT-FFR). MATERIALS AND METHODS: Seventy-seven patients with suspected coronary artery disease were recruited, and they underwent computed tomography angiography (CCTA) before and after NTG administration. The CT-FFRs were compared at 2 CCTAs. The difference was compared using the Wilcoxon signed rank test. Patients were divided into normal and stenosis groups according to CCTA results. Vessels in the stenosis group were further divided into different groups based on coronary artery calcium score (CACS) and stenosis degree. The poststenotic CT-FFR differences before and after NTG (DCT-FFR) were calculated to evaluate the impact of stenosis degree and CACS. Terminal CT-FFRs derived from CCTAs before and after NTG in total and vessel-specific levels were compared in the normal group. RESULTS: Of 47 patients in the stenosis group, poststenotic CT-FFR was significantly increased after NTG at per-vessel level. By taking CT-FFR of 0.75 or lower as the threshold, 5 and 4 patients showed abnormal CT-FFR before and after NTG, respectively. No significant differences were noted among the various stenosis degree and CACS groups regarding DCT-FFR. Of 30 patients in the normal group, terminal CT-FFR was significantly increased after NTG in total level and vessel-specific level of left anterior descending and right coronary artery, but not in the left circumflex. CONCLUSIONS: Both post lesion and distal vessel CT-FFR significantly improved after the administration of GTN with the degree of change not affected by stenosis severity or CACS.

P450s mediated enhanced herbicide metabolism involved in the thifensulfuron-methyl resistance in Ipomoea purpurea L.

Ipomea purpurea (L.) Roth. reduces dry land crop yield and quality in Northeast China, especially in Liaoning Province. Frequent use of thifensulfuron-methyl in recent years has resulted in herbicide resistance in I. purpurea. We evaluated resistance levels of I. purpurea to thifensulfuron-methyl, an acetolactate synthase (ALS) inhibitor, in Liaoning Province and further investigated the resistance mechanisms. The results showed that 15 populations of I. purpurea have evolved up to 5.81-34.44-fold resistance to thifensulfuron-methyl, compared to the susceptible population (S), among which LN3 was the most resistant. DNA sequencing of the ALS gene in susceptible and resistant populations did not reveal any target site mutations that could be associated with resistance to thifensulfuron-methyl in I. purpurea. Additionally, no significant difference was detected between the in vitro ALS activity of LN3 and S. The GR50 of LN3 decreased sharply by 47% when malathion (a P450 inhibitor) was applied with thifensulfuron-methyl. Absorption of thifensulfuron-methyl by LN3 was equal to that of S; however, LN3 metabolized the herbicide significantly faster. This was repressed after the inhibition of P450s activity. Collectively, our results confirmed that I. purpurea in Liaoning Province has developed resistance to thifensulfuron-methyl and implied that the resistance was conferred by the increase in detoxification mediated by P450s. Furthermore, LN3 was sensitive to fluroxypyr, which can be used as an alternative to control I. purpurea.

Food reward depends on TLR4 activation in dopaminergic neurons.

The rising prevalence of obesity and being overweight is a worldwide health concern. Food reward dysregulation is the basic factor for the development of obesity. Dopamine (DA) neurons in the ventral tegmental area (VTA) play a vital role in food reward. Toll-like receptor 4 (TLR4) is a transmembrane pattern recognition receptor that can be activated by saturated fatty acids. Here, we show that the deletion of TLR4 specifically in DA neurons increases body weight, increases food intake, and decreases food reward. Conditional deletion of TLR4 also decreased the activity of DA neurons while suppressing the expression of tyrosine hydroxylase (TH) in the VTA, which regulates the concentration of DA in the nucleus accumbens (NAc) to affect food reward. Meanwhile, AAV-Cre-GFP mediated VTA-specific TLR4-deficient mice recapitulates food reward of DAT-TLR4-KO mice. Food reward could be rescued by re-expressing TLR4 in VTA DA neurons. Moreover, effects of intra-VTA infusion of lauric acid (a saturated fatty acid with 12 carbon) on food reward were abolished in mice lacking TLR4 in DA neurons. Our study demonstrates the critical role of TLR4 signaling in regulating the activity of VTA DA neurons and the normal function of the mesolimbic DA system that may contribute to food reward.

Hemodynamic Comparison of Stent-Grafts for the Treatment of Aortoiliac Occlusive Disease.

PURPOSE: To compare the flow patterns and hemodynamics of the AFX stent-graft and the covered endovascular reconstruction of aortic bifurcation (CERAB) configuration using laser particle image velocimetry (PIV) experiments. MATERIALS AND METHODS: Two anatomically realistic aortoiliac phantoms were constructed using polydimethylsiloxane polymer. An AFX stent-graft with a transparent cover made with a new method was inserted into one phantom. A CERAB configuration using Atrium's Avanta V12 with transparent covers made with a previously established method was inserted into the other phantom, both modified stent-grafts were suitable for laser PIV, enabling visualization of the flow fields and quantification of time average wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT). RESULTS: Disturbed flow was observed at the bifurcation region of the AFX, especially at the end systolic velocity (ESV) time-point where recirculation was noticeable due to vortical flow. In contrast, predominantly unidirectional flow was observed at the CERAB bifurcation. These observations were confirmed by the quantified hemodynamic results from PIV analysis where mean TAWSS of 0.078 Pa (range: 0.009-0.242 Pa) was significantly lower in AFX as compared with 0.229 Pa (range: 0.013-0.906 Pa) for CERAB (p<0.001). Mean OSI of 0.318 (range: 0.123-0.496) in AFX was significantly higher than 0.252 (range: 0.055-0.472) in CERAB (p<0.001). Likewise, mean RRT of 180 Pa-1 (range: 9-3603 Pa-1) in AFX was also significantly higher than 88 Pa-1 (range: 2-840 Pa-1) in CERAB (p=0.0086). CONCLUSION: In this in vitro study, the flow pattern of a modified AFX stent-graft was found to be more disturbed especially at the end systolic phase, its hemodynamic outcomes less desirable than CERAB configuration. CLINICAL RELEVANCE: While the AFX stent-graft has an advantage over the CERAB configuration in eliminating radial mismatch, and maintaining the anatomical bifurcation for future endovascular intervention, this in vitro study revealed that the associated lower TAWSS, higher OSI and RRT may predispose to thrombosis and are, thus, less desirable as compared to a CERAB configuration. Further investigation is warranted to confirm whether these findings translate into the clinical setting.

Shear Wave Elastography of the Maternal Cervix: A Comparison of Transvaginal and Transabdominal Ultrasound Approaches.

OBJECTIVES: This work aimed to compare the use of shear wave elastography on the maternal cervix with transvaginal (TV) and transabdominal (TA) ultrasound approaches to assess differences in shear wave speeds (SWSs) obtained for possible clinical use. METHODS: In both TV and TA ultrasound approaches, SWS measurements were attempted at the anterior and posterior portions of the internal and external cervical os on 38 gravid participants. RESULTS: A larger number of SWS measurements were obtained at the anterior portion of the cervix by both approaches. The numbers of reliable measurements of the SWS obtained at the anterior and posterior portions of the internal and external os were 99, 65, 103, and 77 in the TA approach and 93, 53, 110, and 87 in the TV approach, respectively. The mean difference in -the SWS obtained between the TV and TA ultrasound approaches was statistically significant at the anterior and posterior portions of the internal os, with differences of 0.67 and 0.52 m/s (P < .05). Differences were not significant at the external os both anteriorly and posteriorly, with differences of 0.15 and - 0.07 m/s (P > .05). CONCLUSIONS: Both TA and TV ultrasound approaches may be used to obtain SWSs in the maternal cervix. This study has shown that SWSs obtained by each approach need to be considered independently, as the TV approach produced significantly greater SWSs at the internal os compared to the TA approach, but the values were similar at the external os.