Thoracic Aorta Diameter Calculation by Artificial Intelligence Can Predict the Degree of Arterial Stiffness

Background: Arterial aging is characterized by decreased vascular function, caused by arterial stiffness (AS), and vascular morphological changes, caused by arterial dilatation. We analyzed the relationship of pre-AS and AS, as assessed by cardio ankle vascular index (CAVI), with arterial diameters (AD) at nine levels, from the aortic sinus to the abdominal aorta, as measured by artificial intelligence (AI) on non-enhanced chest computed tomography (CT) images.Methods: Overall, 801 patients who underwent both chest CT scan and arterial elasticity test were enrolled. Nine horizontal diameters of the thoracic aorta (from the aortic sinuses of Valsalva to the abdominal aorta at the celiac axis origin) were measured by AI using CT. Patients were divided into non-AS (mean value of the left and right CAVIs [M.CAVI] < 8), pre-AS (8 ≤ M.CAVI < 9), and AS (M.CAVI ≥ 9) groups. We compared AD differences among groups, analyzed the correlation of age, ADs, and M.CAVI or the mean pressure-independent CAVI (M.CAVI0), Furthermore, we evaluated the risk predictors and the diagnostic value of the nine ADs for pre-AS and AS.Results: The AD at mid descending aorta (MD) correlated strongest with CAVI (r = 0.46, p < 0.001) or M.CAVI0 (r = 0.42, p < 0.001). M.CAVI was most affected by the MD AD and by age. An increase in the MD AD independently predicted the occurrence of pre-AS or AS. For MD AD, every 4.37 mm increase caused a 14% increase in the pre-AS and AS risk and a 13% increase in the AS risk. With a cut-off value of 26.95 mm for the MD AD, the area under the curve (AUC) for identifying the risk of AS was 0.743. With a cut-off value of 25.15 mm, the AUC for identifying the risk of the stage after the prophase of AS is 0.739.Conclusions: Aging is associated with an increase in AD and a decrease in arterial elasticity. An increase in AD, particularly at the MD level is an independent predictor of AS development.

An Analytic Solution for an Expanding/Contracting Strain-Hardening Viscoplastic Hollow Cylinder at Large Strains and Its Application to Tube Hydroforming Design

This paper presents a semi-analytic rigid/plastic solution for the expansion/contraction of a hollow cylinder at large strains. The constitutive equations comprise the yield criterion and its associated flow rule. The yield criterion is pressure-independent. The yield stress depends on the equivalent strain rate and the equivalent strain. No restriction is imposed on this dependence. The solution is facilitated using the equivalent strain rate as an independent variable instead of the polar radius. As a result, it reduces to ordinary integrals. In the course of deriving the solution above, the transformation between Eulerian and Lagrangian coordinates is used. A numerical example illustrates the solution for a material model available in the literature. A practical aspect of the solution is that it readily applies to the preliminary design of tube hydroforming processes.

Guaranteed Upper Bounds For The Velocity Error Of Pressure-Robust Stokes Discretisations

This paper aims to improve guaranteed error control for the Stokes problem with a focus on pressure-robustness, i.e. for discretisations that compute a discrete velocity that is independent of the exact pressure. A Prager-Synge type result relates the velocity errors of divergence-free primal and perfectly equilibrated dual mixed methods for the velocity stress. The first main result of the paper is a framework with relaxed constraints on the primal and dual method. This enables to use a recently developed mass conserving mixed stress discretisation for the design of equilibrated fluxes and to obtain pressure-independent guaranteed upper bounds for any pressure-robust (not necessarily divergence-free) primal discretisation. The second main result is a provably efficient local design of the equilibrated fluxes with comparably low numerical costs. Numerical examples verify the theoretical findings and show that efficiency indices of our novel guaranteed upper bounds are close to one.

Effect of Religious Fasting in Ramadan on Blood Pressure: Results From LORANS (London Ramadan Study) and a Meta‐Analysis

Background Ramadan fasting is practiced by hundreds of millions every year. This ritual practice changes diet and lifestyle dramatically; thus, the effect of Ramadan fasting on blood pressure must be determined. Methods and Results LORANS (London Ramadan Study) is an observational study, systematic review, and meta‐analysis. In LORANS, we measured systolic blood pressure (SBP) and diastolic blood pressure (DBP) of 85 participants before and right after Ramadan. In the systematic review, studies were retrieved from PubMed, Embase, and Scopus from inception to March 3, 2020. We meta‐analyzed the effect from these studies and unpublished data from LORANS. We included observational studies that measured SBP and/or DBP before Ramadan and during the last 2 weeks of Ramadan or the first 2 weeks of the month after. Data appraisal and extraction were conducted by at least 2 reviewers in parallel. We pooled SBP and DBP using a random‐effects model. The systematic review is registered with PROSPERO (International Prospective Register of Systematic Reviews; CRD42019159477). In LORANS, 85 participants were recruited; mean age was 45.6±15.9 years, and 52.9% ( n =45) of participants were men. SBP and DBP after Ramadan fasting were lower by 7.29 mm Hg (−4.74 to −9.84) and 3.42 mm Hg (−1.73 to −5.09), even after adjustment for potential confounders. We identified 2778 studies of which 33 with 3213 participants were included. SBP and DBP after/before Ramadan were lower by 3.19 mm Hg (−4.43 to −1.96, I 2 =48%) and 2.26 mm Hg (−3.19 to −1.34, I 2 =66%), respectively. In subgroup analyses, lower blood pressures were observed in the groups who are healthy or have hypertension or diabetes but not in patients with chronic kidney disease. Conclusions Our study suggests beneficial effects of Ramadan fasting on blood pressure independent of changes in weight, total body water, and fat mass and supports recommendations for some governmental guidelines that describe Ramadan fasting as a safe religious practice with respect to blood pressure.

Creation of a New Explosive Injury Equipment to Induce a Rabbit Animal Model of Closed Globe Blast Injury via Gas Shock

To establish a rabbit animal model of closed globe blast injury with an application of self-developed explosive injury equipment, we tend to explore the anatomic and pathological changes of eyes under different gas pressure. The device comprises of high-pressure air source compression pump, air channel, and gas shock. There were 36 healthy bluish blue rabbits exposed to one of five blast pressures (500, 1,000, 1,500, 2,000, and 5,000 Kpa). Slit lamp microscope, B-mode ultrasonography, fundus photography, optical coherence tomography (OCT), and intraocular pressure (IOP) examination were performed at 0-, 1-, 3-, and 7-days post exposure, while gross histopathology was assessed with H&E stain at 7 days. The contralateral eyes and non-blast exposed rabbits were used as controls. Definitive evidence of closed globe blast injury was obtained. Corneal edema and hyphema were observed in the models under all pressures with no full-thickness globe injury, or lens rupture, as the severity was pressure independent. There was no obvious retinal abnormality on B ultrasound or OCT scan, while light vitreous hemorrhage, commotio retinae, and heavy retinal pigmentation presented on one eye, respectively, in the eyes exposed to 5,000 Kpa. Increased retinal thickness with disorganizations on the retinal ganglion cell (RGC) layer and RGC apoptosis in groups under higher pressure (>500 Kpa). IOP of injured eyes were statistically decreased at day 1 and 7 post injury (p < 0.05). Conclusively, the rabbit animal model induced by self-developed equipment could mimic the clinical features of closed ocular blast injury successfully that was feasible and easy to operate. This will be a new rabbit animal model for investigating mechanisms and new therapeutic interventions of closed globe blast injury in the future.

Automated High-Pressure Atline Analysis of Photo-High-P,T Vitamin D3 Microfluidic Synthesis

Process analytical technology has become a relevant topic in both industry and academia as a mechanism to control process quality by measuring critical parameters; being mainly applied in pharmaceutical industry. An emerging topic is process monitoring with subsequent process automation in flow chemistry using inline, online and atline analyzers. Flow chemistry often deliberately and favorably uses harsh conditions (termed Novel Process Windows) to achieve process intensification which raises the need for sampling under these conditions. This demands for setting in place a stabilization of the sample before exposing it to the processing. Ignoring this may result in being unable to use inline/online analytics and posing the need for a separation step before quantitative analysis, leaving atline analysis as the only feasible option. That means that sampling and connected operations need also to be automated. This is where this study sets in, and this is enabled by a modified high-performance liquid chromatography (HPLC) autosampler coupled to the photo-high-p,T flow synthesis of vitamin D3. It shows that sampling variables, such as decompression speed, can be even more critical in terms of variability of results than process variables such as concentration, pressure, and temperature. The modification enabled the autosampler fully automated and unattended sampling from the reactor and enabled pressure independent measurements with 89% accuracy, >95% reproducibility, and >96% repeatability, stating decompression speed as the primary responsibility for measurements’ uncertainty.

Hypertension drives microbial translocation and shifts in the fecal microbiome of non-human primates

Accumulating evidence indicates a link between gut barrier dysfunction and hypertension. However, it is unclear whether hypertension dictates gut barrier dysfunction or vice versa and whether the gut microbiome plays a role. To better understand this relationship, first, we cross-sectionally examined hypertension and other cardio-metabolic risk factors and gut barrier function in a population of 150 nonhuman primates. Interestingly, the animals with hypertension showed evidence of gut barrier dysfunction (i.e., translocation of microbes through the gut wall), as indicated by higher plasma levels of lipopolysaccharide-binding protein (LBP)-1, compared to normotensive animals. Further, plasma LBP-1 levels were strongly correlated with diastolic blood pressure, independent of age and other health markers, suggesting specificity of the effect of hypertension on microbial translocation. In a subsequent longitudinal study (analysis at baseline, 12 and 27 months), hypertensive animals had higher plasma levels of LBP-1 at all the time points and greater bacterial gene expression in mesenteric lymph nodes compared to normotensive animals, confirming microbe translocation. Concomitantly, we identified distinct dysbiosis in the gut microbial signature of hypertensive versus normotensive animals at 12 and 27 months. These results suggest that hypertension drives microbial translocation in the gut and eventually unhealthy shifts in the gut microbiome, possibly contributing to poor health outcomes, providing further impetus for the management of hypertension.