Mechanical approach of some liver diseases and their impact on hemodynamics.

Is a history of umbilical vein catheterization a contraindication to Meso-Rex bypass for extrahepatic portal vein obstruction in children?

(Bi 2 Te 3 ) x (Sb 2 Te 3 ) 1- x thin films were synthesized using the pressure-gradient-sputtering (PGS) system, and the complex relationship between film thickness, composition, and multi-scale structure was systematically investigated. A hallmark of this study is the observation of a significant structural transition facilitated by the PGS process; while the system establishes a high-quality c -axis-oriented template at the early growth stage, Bi-rich films exhibit a dramatic degradation in orientation ( F -value from 0.97 to 0.17) as thickness increases. This orientation loss is attributed to the stress relaxation-induced grain tilting inherent to the Bi-rich lattice. Remarkably, despite this pronounced structural deterioration, the thermoelectric properties—Seebeck coefficient, electrical conductivity, and power factor—remain nearly invariant across a broad thickness range (0.5 to 4.2 μm). This suggests that the electronic transport is predominantly governed by the stable initial layer formed under the high-energy particle flux of the PGS process, effectively decoupling functional performance from bulk structural changes. Optimization of the composition yielded maximum power factors of 21 μW/(cm‧K 2 ) for p -type ( x = 0.24) and 6.7 μW/(cm‧K 2 ) for n -type ( x = 0.73). These findings demonstrate that the PGS system provides a unique growth kinetic that ensures thickness-tolerant performance even under significant structural instability, offering a robust platform for scalable micro-thermoelectric devices.

The VIATORR Controlled Expansion (VCX) stent-graft was developed to allow more precise control of shunt diameter during transjugular intrahepatic portosystemic shunt (TIPS) creation. However, real-world data on its actual in vivo expansion behavior and short-term clinical implications remain limited. This study aimed to provide fluoroscopic quantitative assessment of early in vivo expansion of VCX stent-grafts and to assess its association with short-term overt hepatic encephalopathy (OHE). This single-center retrospective cohort included consecutive patients with cirrhosis who underwent TIPS using either a legacy 8-mm VIATORR TIPS stent-graft (VTS) or a VCX stent-graft. In the VCX group, stents were initially dilated to 8mm and further dilated to 10mm only when post-procedural portal pressure gradient (PPG) remained > 12 mmHg or decreased by < 50% from baseline. Propensity score matching (PSM) was performed to compare short-term clinical outcomes between the VCX and VTS groups. The primary imaging outcome was early in vivo expansion of the VCX controlled mid-segment, assessed by fluoroscopic diameter measurements at implantation and 3-month follow-up. The main clinical safety outcome was new-onset OHE within 6 months after TIPS. A total of 177 patients were included (108 VTS and 69 VCX). Among VCX patients with paired imaging follow-up, the mid-segment diameter increased from 8.0mm at implantation to a mean of 8.65mm at 3 months (range 8.2-9.1mm; p < 0.001). Mean post-TIPS PPG increased from 7.7 mmHg immediately after TIPS to 11.6 mmHg at 3 months (p < 0.001), with no significant correlation between diameter change and PPG change. After PSM, 132 patients were analyzed. The cumulative 6-month incidence of OHE was numerically higher in the VCX group but did not reach statistical significance compared with VTS (HR 11.74, 95% CI 0.73-4.16; log-rank p = 0.204). VCX stent-grafts exhibit measurable early self-expansion after implantation, indicating that the controlled-expansion segment may not remain fixed at the intended 8-mm diameter during early follow-up. While the incidence of OHE did not differ significantly between the VCX group and the VTS group after PSM, the observed expansion underscores the dynamic nature of post-TIPS stent behavior and supports imaging-based follow-up of shunt configuration and hemodynamic status.

This study employs numerical simulations to analyse the flow field characteristics around the bow of a research vessel under drift angles of 0°, 10°, and 20°, as well as during turning motions. The investigation focuses on how different operating conditions influence the velocity, pressure, streamline distribution, and vortex structures. Results indicate that an increase in drift angle leads to more complex flow patterns and vortex evolution, which consequently intensifies hull rolling and turbulence, thereby affecting navigation stability. Variations in pressure gradients alter the streamline distribution along the hull surface, modifying ship forces and the surrounding flow, and contributing to bubble sweep-down near the bow. During turning motion, the flow field evolves through four sequential stages—straight sailing, yawing, deceleration, and steady rotation—each corresponding to distinct ship motion states and exhibiting clear stage-dependent changes in flow structure and hydrodynamic performance. The identified flow mechanisms, particularly the strong downwash and vortex dynamics under high drift angles, provide critical insights for assessing and mitigating acoustic interference risks for research vessels during complex manoeuvring operations.

Psychological distress is common yet often underrecognized in chronic obstructive pulmonary disease (COPD). Physiological correlates beyond spirometry may support biopsychosocial assessment in routine care, but their relation to depressive and anxiety symptoms remain insufficiently characterized. In this single-center cross-sectional study, 56 clinically stable Japanese COPD outpatients (mean age 73 years; 87.5% men) completed the Self-Rating Depression Scale (SDS) and the State-Trait Anxiety Inventory (STAI). Clinical assessments included spirometry, %DLCO/VA, echocardiographic tricuspid regurgitation pressure gradient (TRPG), body mass index (BMI), and blood biomarkers. Associations were examined using Spearman's rank correlation and multivariable linear regression adjusted for age, sex, and BMI; Model 1 included %DLCO/VA and Model 2 included TRPG. Bootstrap resampling was used to assess the stability of key regression coefficients. Depressive symptoms (SDS ≥ 40) were present in 46.5% of the patients (severe 5.4%), and elevated state anxiety in 41.1% (severe 12.5%). SDS scores were correlated with lower %DLCO/VA, higher TRPG, and lower BMI. STAI-state scores were correlated with higher TRPG. In adjusted analyses, lower %DLCO/VA was independently associated with higher SDS scores, whereas higher TRPG was independently associated with higher SDS and STAI-state scores. %FEV1 was not associated with SDS or STAI scores. In this Japanese outpatient COPD cohort, depressive and anxiety symptoms were common. Elevated TRPG showed a more consistent association with psychological symptoms in bootstrap analyses, whereas lower %DLCO/VA was associated with depressive symptoms but showed less stable bootstrap support than the TRPG findings. These findings support an integrated biopsychosocial assessment approach to routine COPD care, incorporating physiological information beyond spirometric airflow measures.

Abstract Some aspects of synoptic to subseasonal variability of currents in the southern Japan/East Sea (JES) were investigated using high-resolution current measurements and reanalysis model products. Current measurements were made at multiple moorings containing acoustic Doppler current profilers (ADCPs) deployed during MJES (Mixing in the Japan/East Sea, 2021–2022) and LINKS (Linkages of Asian Marginal Seas, 1999–2000) programs. MJES measurements were collected over the southern slope of the Ulleung Basin (SSUB) and near the southeastern coast of Korea, and LINKS measurements were collected within the Korea-Tsushima Strait (KTS). Both LINKS and MJES observations revealed synoptic (2–7 days) to subseasonal (7–30 days) velocity fluctuations. Specifically, velocity fluctuations in the East Korea Warm Current on the southeastern Korean shelf from March to June 2022 reached magnitudes of 0.3 m s⁻ 1 , with broad periods ranging from 10 to 15 days. Local winds and currents were highly correlated here with a coherence of 0.95 at 12–13-day periods and a 2.7-day lag. Similar velocity fluctuations were observed at moored ADCPs on the SSUB and the northwestern corner of the KTS, but without any significant correlations between winds and currents. However, atmospheric surface-pressure distributions over the JES displayed 10–15 day oscillating along-basin pressure gradients of magnitudes $$\sim$$ 10 –5 mb m −1 . Our analysis suggests that wind and atmospheric pressure-gradient forcing can be important forcing mechanisms for generating the observed velocity fluctuations in the southern JES.

The quantitative flow ratio (QFR)-derived pullback pressure gradient (PPG) characterizes the pathophysiological patterns of coronary atherosclerosis. This study investigated the plaque morphologies associated with these disease patterns. This study used the institutional QFR-PPG database registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN000056097). Patients who underwent elective stenting with pre-procedural optical coherence tomography and near-infrared spectroscopy intravascular ultrasound were included. Offline QFR and QFR-PPG analyses were performed, and the lesions were stratified into tertiles. A total of 168 de novo lesions were analyzed in this study. The QFR tertiles were defined as severe (＜0.61), moderate (0.61-0.71), and mild (＞0.71); the QFR-PPG tertiles were defined as diffuse (＜0.66), intermediate (0.66-0.79), and focal (＞0.79). The Severe QFR tertiles exhibited a smaller minimum lumen area (MLA) and higher frequencies of thin-cap fibroatheroma (TCFA) and layered plaque. In contrast, across the QFR-PPG tertiles, MLA and TCFA frequencies were similar, whereas the diffuse group exhibited more layered plaques and larger calcium angles. The maximum lipid-core burden index did not vary across the QFR-PPG tertiles. A multivariable analysis identified MLA and TCFA as independent predictors of QFR, while layered plaque and calcium angle independently predicted QFR-PPG. However, the lipidic features were not independent predictors of QFR. Multimodal intracoronary imaging demonstrated that QFR reflects luminal narrowing and the features of vulnerable plaques. Conversely, QFR-PPG reflects disease diffuseness, characterized by layered plaques and calcium burden rather than lipid-rich features.

The present study investigates transient nanofluid flow in a vertical porous channel with buoyancy effects and Navier slip at the walls, with particular emphasis on thermodynamic irreversibility, entropy generation, and mixed convection. The study formulates dimensionless, coupled nonlinear governing equations for velocity, temperature, and entropy generation. These equations are solved numerically using a finite-difference scheme (FDS) that is second-order accurate in space and first-order accurate in time, capturing both transient and steady-state behaviors. Parametric analyses are conducted for permeability (Darcy number), buoyancy (Grashof number), pressure gradient, Biot number, Prandtl number, Brinkman number, and distinct Navier slip coefficients at the heated and cooled walls. Increasing permeability and buoyancy accelerate the flow and enhance convective heat transfer, but intensify entropy generation near the walls where velocity and temperature gradients are highest. Stronger pressure forcing sharpens the centerline velocity and increases near-wall irreversibility. Higher Biot and Prandtl numbers reduce velocity and temperature levels across the channel, while potentially increasing entropy generation due to steeper thermal gradients. Increased viscous dissipation raises temperatures near the heated wall and amplifies entropy generation near both plates.

The global current systems of a planet represent electrodynamic interactions between its different parts, and between its magnetosphere and the ambient solar wind. Although some local currents of Mercury's magnetosphere have already been revealed by previous observational studies, the global picture of current systems in Mercury's magnetosphere remains unknown. Here we reconstruct the global current systems in the Mercury's magnetosphere, using five years magnetic field and plasma measurements made by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. It reveals a complex picture: a magnetopause current, cross-tail current, inner and outer equatorial ring currents and an unexpected polar ring current. The equatorial ring currents and the polar ring current agree with the prediction of the plasma drifting model in a region with a pressure gradient. These ring currents could reshape Mercury's magnetosphere and reveal new dynamics and energy transfer processes in Mercury.

Hygroscopic hydrogels are promising materials for high-efficiency sorption-based atmospheric water harvesting (SAWH); however, their practical application is constrained by intrinsically slow water transport within the collapsed dehydrated polymer networks, a process predominantly governed by osmotic pressure gradient (∇πos). Here, we develop a rigid-polymer-network-based interconnected macroporous hygroscopic hydrogel (HRIMP) via a facile foaming-assisted polyelectrolyte diffusion-complexation strategy, enabling ultrafast sorption/desorption kinetics for high-efficiency SAWH. The antishrinkage rigid network resists structural collapse during dehydration, preserving a hierarchical porous architecture that synergistically combines ∇πos with capillary pumping to accelerate water transport beyond the limitations of conventional hydrogels. Consequently, the HRIMP exhibits excellent sorption/desorption kinetics across a wide humidity range, achieving equilibrium water uptake within just 45 and 90 min at 30% and 90% relative humidity (RH), respectively, and releasing 83.4% of adsorbed water within only 29.5 min under one sun irradiation. Leveraging this ultrafast kinetics, we design a continuous cyclic SAWH device that maintains high water productivity (1.07 Lwater kgsorbents-1 day-1) even under cold, dry winter conditions (around 0 °C, 43% RH). This rigid-network design strategy provides a generalizable approach to overcome the inherent mass-transfer limitations of gel-based adsorbents, promoting the practical application of high-performance SAWH systems.

Quantitative 3D-TEE Analysis of Mitral Valve Geometry for TEER Strategy in Atrial Functional Mitral Regurgitation.

Prognostic Value of Coronary Sinus Flow and Aortic Pressure Gradient Quantified by 4D Flow CMR in AMI.

Transmitral Pressure Gradient and Residual Mitral Regurgitation After Transcatheter Edge-to-Edge Repair in Patients With and Without Hemodialysis.

Three-dimensional (3D) multicellular ex vivo cultures have become central tools for cancer research and drug testing under physiologically relevant conditions. Organ-on-a-chip technologies based on microfluidics provide platforms for culturing and analyzing 3D tissues under flow. However, maintaining long-term continuous perfusion typically requires pumps and complex tubing networks, increasing operational complexity, cost, and limiting scalability for routine use. Pumpless approaches have been explored but often suffer from short flow duration, inconsistent unidirectional perfusion, and frequent reservoir replenishment. Here, we present a vertical pump-free fluidic platform designed for spheroid formation, culture, and biological testing. The system integrates molds for spheroid assembly with a modular 3D-printed culture chamber that allows direct sample access. A stackable cartridge-like design enables parallel assays under identical conditions, while the incorporation of commercially available syringes as structural elements improves standardization and reduces the footprint. Continuous perfusion over several days is achieved using a hydrogel-based flow resistor that generates passive pressure gradients. Using three human ovarian cancer cell lines (Ovcar-3, A2780, and Ovcar-8), we demonstrate the formation of uniform spheroids that maintain viability and metabolic activity for up to one week within the 3D-printed cartridges. Drug response was evaluated using paclitaxel, with measurable effects on spheroid growth and invasion. Flow simulations and experimental measurements confirm stable perfusion for approximately 3 days, followed by a gradual decline until cessation at day 7. Overall, this pump-free platform provides a scalable, modular solution for controlled 3D culture and multi-functional assays without external pumping systems.

ObjectivesTo evaluate the diagnostic performance of four-dimensional flow MRI alone and in combination with spleen volume and splenic extracellular volume fraction (ECV) for identifying high-risk esophageal variceal (HRV) in patients with liver cirrhosis.Materials and methodsA total of 58 cirrhosis patients who underwent four-dimensional flow MRI and endoscopy were prospectively recruited and were divided into HRV group (n = 25) and non-HRV (NHRV) group (n = 33). The hemodynamic parameters of the portal vein (PV), superior mesenteric vein (SMV), and splenic vein (SV) derived from four-dimensional flow MRI for identifying HRV were analyzed and compared with spleen volume and splenic ECV. Then a combined model for identifying HRV was constructed by using the least absolute shrinkage and selection operator (LASSO) regression and multivariate logistic regression analysis with stepwise forward.ResultsThe peak velocity and maximum pressure gradient of the PV, SMV, and SV, as well as the total volume of the SMV, were significantly greater in the HRV group than in the NHRV group. The SV peak velocity had the highest AUROC for identifying HRV and was comparable to the spleen volume and splenic ECV. The combined model incorporating these three indicators showed superior performance with an AUC of 0.945, outperforming individual imaging indicators and other laboratory-based models.ConclusionFour-dimensional flow MRI is a valuable noninvasive technique for detecting HRV in cirrhosis patients. The combined model incorporating SV peak velocity, spleen volume, and splenic ECV provided an accurate prediction of HRV, which may help avoid unnecessary screening endoscopy.Critical relevance statementThe combined model incorporating spleen vein peak velocity derived by 4D flow MRI, spleen volume, and spleen ECV performed better than individual imaging indicators and laboratory-based models, which may help to avoid unnecessary screening endoscopy and aid in clinical decision-making.Key PointsNoninvasive assessment of the risk of HRV in cirrhosis remains crucial but inadequate.Four-dimensional flow MRI can effectively identify HRV in patients with cirrhosis.Combining SV peak velocity, splenic volume, and ECV effectively identifies HRV.Graphical

The nasal passages of bats that emit their echolocation call through their nostrils have adapted for sound emission as well as standard respiratory and olfactory functions. Rhinolophids, hipposiderids and rhinonycterids all use a high duty cycle (HDC) echolocation strategy. In this study we used computational fluid dynamics (CFD) to simulate airflow through models of the nasal passages of 12 members of Rhinolophoidea, with the aim of gaining a greater insight into how differences in nasal passage anatomy and echolocation strategy influence airflow. We also aimed to gain greater insight into the function of the unique strands housed in the rhinolophid nasal passage, by comparing models with the strands intact and digitally removed. We found that nasal passage anatomy (e.g., the presence or lack of an ethmoturbinal I projecting into the rostral part of the nasal chamber), not echolocation strategy (HDC vs. low duty cycle) appeared to influence simulated airflow patterns and rates. Further, our results revealed digital removal of the unique strands within the nasal passages of the rhinolophids resulted in a reduction in the overall pressure gradient across the nasal passage models and altered the airflow patterns. How this pressure gradient change influences either the functions of echolocation and/or respiration warrants further investigation.

Novel stent technologies offer early intravascular treatment options for coarctation (COA). Mid-to-long-term cardiovascular responses to early COA stent interventions are undefined. We studied a porcine model of COA, with and without early stent implantation with serial dilation to adult aortic diameters, aiming to define longitudinal cardiovascular changes. In total, 18 swine were studied: 6 shams, 6 COA controls (CC), and 6 COA stents (CS). Surgical COA was induced at 2 weeks (4.5 kg) followed by stent implant at 6 weeks, with serial dilations at 12 and 20 weeks (80 kg). All animals were terminally studied at 20 weeks. Successful stent implantation with serial dilation matching somatic growth occurred in all CS animals with predictable stent performance and elimination of COA. No in-stent stenosis observed. Final stent dimensions equaled the proximal descending aorta (DAo) of shams (16.8 ± 1.5 vs. 17.5 ± 0.8, p = 0.3); however, DAo narrowing (13.3 ± 1.1 mm) just distal to the stent without gradient was created because of stent shortening, and this DAo segment demonstrated decreased vessel wall collagen content. Four of 6 animals developed peri-stent aneurysms treated with covered stents. CS prevented post stenotic dilation and collateralization and resulted in near normalization of catheter-derived hemodynamics. Cardiac MRI documented similar ventricular function, cardiac index, and myocardial tissue characterization between groups. Early COA stenting was associated with increased systemic arterial elastin content. In this swine COA model, early stent implants effectively dilated to adult aortic dimensions, prevented blood pressure gradients, collateralization, and adverse myocardial remodeling. Early stenting with serial dilations altered systemic arterial elastin content, and additional stents may be necessary to enlarge the adjacent DAo. Aneurysm formation frequently occurred.

Despite the effectiveness of the surgical or percutaneous treatment of coarctation of the aorta, the presence of hypertension in these patients remains a common and concerning issue. This study was undertaken to explore the relation between the severity of coarctation of the aorta and renal perfusion and to evaluate the role of renal scintigraphy as a predictive tool for clinical outcomes after percutaneous treatment of coarctation of the aorta. Adult patients with coarctation of the aorta and concomitant arterial hypertension were enrolled in the study. Ambulatory 24-hour blood pressure monitoring, CT angiography, and a renal perfusion scan were performed, along with invasive pressure gradient measurements. Patients with invasive peak gradients ≥20mmHg and/or a difference of ≥50% in diameter between the isthmus and the descending aorta at the diaphragmatic level were selected for percutaneous stent implantation. The mean time to peak change in renal scintigraphy after captopril did not significantly differ between the Medical group (-1.01 ± 2.526 min. for the left kidney and -0.19 ± 1.46 min. for the right kidney) and the Stent group (-0.59 ± 1.188 min. for the left kidney and -0.17 ± 1.461 min. for the right kidney) (p-values > 0.05). No statistically significant changes in renal perfusion were observed between pre-and post-stent implantation measurements. In this pilot study, no clear association was found between the degree of aortic narrowing and renal perfusion, and no measurable reduction in renal perfusion was detected. Stent implantation did not result in significant short-term changes in blood pressure. These findings are exploratory and require confirmation in larger studies.

Polymer hydrogels are the optimal hydrogels for water channeling control applications, and water-dominant channels in deep reservoirs are often blocked by them.A dual-network hydrogel system (DN-Gel) is innovatively proposed in this study. A chemical crosslinking network (ACL-HG) is constructed via glycidyl methacrylate (GMA), poly(ethylene glycol) methyl ether methacrylate (PEGMA), and dopamine methacrylamide (DMA), and is composited with a physical crosslinking network (GQDs-Gel) of functionalized graphene quantum dots (GQDs-GX)/ascorbic acid. A dense dual-network structure is formed through the synergistic effect of Michael addition reaction and hydrogen bonding.FTIR and SEM characterization results show that DN-Gel possesses both the functional group characteristics of the chemical crosslinking network and the nano-reinforcement effect of the physical crosslinking network, and its cross-sectional pore structure is significantly denser than that of single-network hydrogels.Under the optimal ratio and concentration, the viscosity reduction rates of DN-Gel both before and after three shearing cycles within 56 days are maintained below 20%.Under high-temperature and high-salinity conditions, a mass retention rate of over 80.6% is achieved after 60 days.Core simulation results show that DN-Gel has a breakthrough pressure gradient of 129.21MPa/m and a permeability change rate as high as 99.21%, which is significantly improved compared with traditional plugging agents.This study provides a new material design method and theoretical basis for the green and efficient plugging of sandstone reservoirs.