Search Results (55)

Background: Both-bone forearm fractures (BBFF) are among the most common pediatric injuries. While most cases in younger children can be managed non-operatively, older children and adolescents exhibit less predictable remodeling and longer healing times, potentially leading to higher complication rates. This study aimed to evaluate sex-based anatomical differences in BBFF and their association with complications. Methods: We retrospectively reviewed 163 patients (129 boys, 34 girls; age range: boys > 10 years, girls > 8 years, both < 16 years) with unilateral BBFF treated between 2017 and 2020. All underwent biplanar radiographs of both forearms pre-reduction, post-reduction, and at 8-week follow-up. Measurements included radius and ulna angulation, bone length, maximum radial bow (%), and location of maximum bow (mm). Complications and surgical interventions were recorded. Results: Boys demonstrated significantly greater initial radius angulation on the lateral view (p < 0.05) and longer radius and ulna lengths on the unaffected side (p < 0.05). Maximum radial bow (%) did not differ between sexes; however, the location of maximum bow varied between unaffected and fractured sides within each sex (p < 0.05). Twenty boys (15.5%) required surgery, compared with none of the girls (p = 0.007). Overall complication rates were 44.8% (n = 73) with no significant sex difference (p = 0.074). Conclusions: In older children and adolescents with BBFF, boys exhibit anatomical characteristics—such as longer forearms and greater initial angulation—associated with unstable fracture patterns and higher surgical intervention rates. Recognizing these differences may improve early risk stratification and management strategies. Level of Evidence: IV. Full article

The large-scale deployment of wind energy underscores the critical need for accurate resource characterization to reduce uncertainty in power estimates and to enable the installation of wind farms in increasingly complex terrains. Accurate wind resource assessment in peri-urban and moderately complex terrains remains a significant challenge due to spatial heterogeneity in surface terrain features and atmospheric thermal stability. This study investigates the influence of surface complexity and atmospheric stratification on vertical wind profiles at a utility-scale wind turbine site in Cedar Rapids, Iowa. One year of multi-level wind data from a 106-meter-tall meteorological tower were analyzed to quantify variations in the wind shear exponent $\alpha$, wind direction veer, and horizontal turbulence intensity (TI) across open-field and complex-surface wind sectors and four thermal stability classes, defined by the bulk Richardson number $R{i}_b$. The results show that the wind shear exponent $\alpha$ increases systematically with atmospheric stability. Over the open-field terrain, $\alpha$ ranges from 0.11 in unstable conditions to 0.45 in strongly stable conditions, compared to 0.17 and 0.40 over the complex surface. A pronounced diurnal variation in $\alpha$ was observed, particularly during the summer months. Wind veer was greatest and exceeded 30° under strongly stable conditions over open terrain. Elevated TI values peaked at 32 m in height due to flow separation and wake turbulence from nearby vegetation and sloping terrain. These findings highlight the importance of incorporating terrain-induced and thermally driven variability into wind resource assessments to improve power prediction and turbine siting in complex heterogeneous terrain environments. Full article

Gravity waves play a crucial role in the evolution of convective systems. The unique thermal structure of elevated convection occurring above a stable boundary layer facilitates the generation and propagation of gravity waves. This study focuses on an elevated convection event over Central China on the night of 2–3 February 2024. The WRF model, combined with terrain sensitivity experiments, is employed to analyze the characteristics of gravity waves and the effects of terrain variability. The event consists of two elevated convection clusters; the first triggers gravity waves on its southwestern side, which subsequently initiates the second convection cluster. The gravity waves exhibit a horizontal wavelength of 25 km and a period of 17.5 min, propagating eastward. Below an altitude of 3 km, a stable wave duct layer is present, overlain by an unstable overreflective zone. This stratification creates an ideal channel for ducted gravity wave propagation, which is essential for maintaining the waves. Sensitivity experiments confirm that convective forcing alone is sufficient to generate the observed gravity waves. Although the terrain lies within the stable boundary layer, its ruggedness modulates the distribution of waves and indirectly influences the organization of elevated convection. Full article

Objectives: The mechanisms linking vitamin D deficiency to carotid artery stenosis (CAS) remain unclear. Data on cardiovascular outcomes in CAS patients with vitamin D deficiency are limited. We investigated the association of vitamin D deficiency with carotid plaque morphology and patient outcomes in high-grade CAS. Methods: A total of 332 patients undergoing carotid endarterectomy for symptomatic (n = 113, 34%) or asymptomatic (n = 219, 66%) CAS were included. Preoperative vitamin D levels were measured, and duplex sonography was used to assess luminal narrowing. Associations of vitamin D with clinical presentation were analyzed using univariate and multivariate linear regression. For vitamin D deficiency and the prediction of major adverse cardiovascular events (MACE) and all-cause mortality, the Cox proportional hazard regression model was used. Results: The median age was 69 years (interquartile range (IQR) 64–74), and 94 (29.3%) patients were female. Vitamin D deficiency was present in 84 (25%) patients. Symptomatic patients had significantly lower vitamin D levels (41.2 nmol/L, IQR 25.1–63.5) than asymptomatic patients (51.6 nmol/L, IQR 30.5–74.3, p = 0.011). Patients with echolucent (44.9 nmol/L, IQR 27.4–73.7) or mixed plaques (39.2 nmol/L, IQR 22.9–63.5) had lower vitamin D levels than those with echogenic plaques (52.3 nmol/L, IQR 34.1–75.7). Vitamin D deficiency predicted MACE and all-cause mortality with an adjusted HR of 1.6, 95% CI of 1.1–2.6, and p = 0.030 and an HR of 2.2, 95% CI of 1.3–3.6, and p = 0.002, respectively, in a multivariable Cox proportional hazard regression model. Conclusions: A deficiency in vitamin D was correlated with unstable plaque characteristics and symptomatic CAS. Furthermore, vitamin D deficiency was associated with long-term adverse cardiovascular outcomes and mortality, suggesting its potential as a modifiable risk factor for improved risk stratification in patients undergoing carotid endarterectomy. Full article

This study evaluated the effects of photovoltaic (PV) arrays on critical surface parameters through analysis of observational data collected from a utility-scale PV power station located in Wujiaqu City, Xinjiang, in 2021. The results reveal that: (1) Installation of PV panels reduces surface albedo, which is significantly altered by dust storm conditions; (2) the installation of PV arrays increases the aerodynamic and thermal roughness length by increasing the frictional velocity across the mixed underlying surface; (3) the overall transport coefficients within the PV plant are higher than that of the reference site, with greater diurnal variation than nocturnal variation. The overall transport coefficient is highest in the unstable stratification conditions and lowest under stable stratification conditions; and (4) soil thermal property parameters exhibit seasonal variations. Significant changes in thermal conductivity and specific heat capacity were observed during spring thaw, high and fluctuating diffusivity in summer, and low and stable values in winter. The findings demonstrate that installing PV arrays in arid regions modifies surface energy balance and heat transfer characteristics. This provides a basis for optimizing PV station layouts and conducting climate impact assessments. Full article

Background/Objectives: Carotid artery disease is a condition affecting 3% of the general population which significantly contributes to the development of cerebrovascular events. Fibroblast Growth Factor-23 (FGF-23) is a hormone that has been linked to atherosclerosis and increased cardiovascular risk, including stroke and myocardial infarction. This review explores the association of FGF-23 with carotid artery disease progression in an endarterectomy clinical context. Methods: Based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), a search was performed relying on MEDLINE, Scopus and Web of Science, identifying publications focused on the correlation between serum FGF-23 and carotid artery disease. Assessment of study quality was made using National Heart, Lung and Blood Institute Study Quality Assessment Tool (NHLBI). Results: Three observational studies, comprising 1039 participants, were included. There was considerable heterogeneity among the populations from the different studies. Elevated FGF-23 levels were consistently associated with unstable plaque features, including intraplaque neovascularization, as identified through Superb Microvascular Imaging (SMI). Plasma levels of inflammatory mediators, such as Interleukin-6 (Il-6), Monocyte Chemoattractant Protein-1 (MCP-1), and Osteoprotegerin (OPG), positively correlated with carotid artery disease, but their link to unstable plaques is conflicting. None of the studies investigated clinical complications following carotid endarterectomy. Conclusions: FGF-23 is a potential biomarker for plaque vulnerability in carotid disease. Despite promising findings, limitations such as small sample sizes and lack of longitudinal data suggest the need for larger and more diverse studies to improve risk stratification and inform personalized treatment strategies for carotid atherosclerosis. Full article

Tsuga forrestii Downie, a vulnerable species endemic to China, is confined to small, fragmented habitats in the northwestern Yunnan and southwestern Sichuan Provinces, China. Understanding the current status of its communities and populations is crucial for protecting existing natural forest resources. We surveyed 33 plots in Yunnan and Sichuan, where T. forrestii is the primary dominant species. We analyzed their community characteristics including vertical stratification, species diversity, and population structure, and classified them into four distinct forest types: (1) Tsuga forrestii evergreen coniferous forest; (2) Tsuga forrestii-Lithocarpus variolosus evergreen coniferous and broad-leaved mixed forest; (3) Tsuga forrestii-Quercus guyayifolia evergreen coniferous and broad-leaved mixed forest; (4) Tsuga forrestii-Abies forrestii evergreen coniferous forest. These forests exhibited a multilayered vertical structure, and T. forrestii as a dominant species appeared in the arborous and shrub layers, and the associated taxa were mainly species of Abies, Lithocarpus, Quercus, Castanopsis, and Rhododendron. No significant differences in species richness or diversity indices or phylogenetic relatedness metrics among the forest types were found. The maximum age of the remaining wild specimens was 344 years, with individuals under 20 years or over 170 years old being rare. The average growth rate of T. forrestii, based on ring width, fluctuated over time, and the range of mean values was 0.92 to 3.31 mm/year. Established seedlings/saplings were rare and mainly found in unstable microhabitats. These findings highlight the poor regeneration and a decline in its populations. Improving its regeneration status is crucial to maintaining its population status. Full article

Background/Objectives: Vitamin K2 analogs are associated with decreased vascular calcification, which may provide protective benefits for individuals with coronary artery disease (CAD) by stimulating anti-calcific proteins like matrix Gla protein and adjusting innate immune responses. This study addresses a significant gap in understanding the association between serum levels of vitamin K2 analogs in different CAD types and examines their correlations with clinical risk parameters in CAD patients. Methods: This case–control study enrolled CAD patients and healthy controls to assess and compare serum concentrations of two vitamin K2 analogs including menaquinone-4 (MK-4) and menaquinone-7 (MK-7) via ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS). CAD risk factors were evaluated and related to serum levels of vitamin K2 analogs. The CAD group was further subdivided into stable angina, STEMI, NSTEMI, and unstable angina groups to investigate potential differences in vitamin K2 analog levels. Results: Patients experiencing acute coronary syndrome exhibited notably reduced serum levels of MK-4 and MK-7 (1.61 ± 0.66, and 1.64 ± 0.59 ng/mL, respectively) in comparison to the control group (2.29 ± 0.54, and 2.16 ± 0.46 ng/mL, respectively), with MK-4 and MK-7 displaying stronger associations with CAD risk indicators. Notable variations in vitamin K2 analog levels were found between CAD patients and control groups (p < 0.001). Unstable angina patients showed the lowest serum levels of MK-4 and MK-7. Conclusions: The present study demonstrated a higher prevalence rate of vitamin K2 deficiency among patients with CAD. The most pronounced decrease in MK-4 and MK-7 was observed in unstable angina patients. Moreover, these outcomes indicate the imperative requirement for an integrative approach that incorporates metabolic, lipid, and vitamin K2-related pathways in the risk stratification and management of CAD. Full article

In Cartesian coordinates $\left(x,y,z\right),$ the gradient Richardson number $Ri$ is the ratio between the square of the buoyancy frequency N and the square of the vertical shear S, $Ri=N^2/S^2$, where $N^2=-\left(g/\rho \right)\partial \rho /\partial z$ and $S^2={\left(\partial u/\partial z\right)}^2+{\left(\partial v/\partial z\right)}^2$, with ρ potential density, $\left(u,v\right)$ the horizontal velocity components and g gravity acceleration. In isopycnic coordinates $\left(x,y,\rho \right)$, $Ri$ is expressed as the ratio between ${M^2\equiv N}^{-2}$ and the squared diapycnal shear ${S_{\rho }}^2={\left(\rho /g\right)}^2\left[{\left(\partial u/\partial \rho \right)}^2+{\left(\partial v/\partial \rho \right)}^2\right]$, $Ri=M^2/{S_{\rho }}^2$. This could suggest that a decrease (increase) in stratification brings a decrease (increase) in dynamic stability in Cartesian coordinates, but a stability increase (decrease) in isopycnic coordinates. The apparently different role of stratification arises because S and $S_{\rho }$ are related through the stratification itself, $S_{\rho }=S/N^2$. In terms of characteristic times, this is equivalent to $\tau \equiv S_{\rho }={t_o}^2/t_d$, which is interpreted as a critical dynamic time $\tau$ that equals the buoyancy period $t_o\equiv N^{-1}$ normalized by the ratio $t_d/t_o$, where $t_d=S^{-1}$ is the deformation time. Here we follow simple arguments and use field data from three different regions (island shelf break, Gulf Stream and Mediterranean outflow) to endorse the usefulness of the isopycnal approach. In particular, we define the reduced squared diapycnal shear ${{\sigma }_{\rho }}^2={S_{\rho }}^2-M^2$ and compare it with the reduced squared vertical ${\sigma }^2=S^2-N^2$, both being positive (negative) for unstable (stable) conditions. While both Ri and ${\sigma }^2$ remain highly variable for all stratification conditions, the mean ${{\sigma }_{\rho }}^2$ values approach ${S_{\rho }}^2$ with increasing stratification. Further, the field data follow the relation ${{\sigma }_{\rho }}^2=\left(1-Ri\right)/\left(N^{2}Ri\right)$, with a subcritical $Ri=0.22$ for both the island shelf break and the Mediterranean outflow. We propose ${{\sigma }_{\rho }}^2$ and ${S_{\rho }}^2$ to be good indexes for the occurrence of effective mixing under highly stratified conditions. Full article

The increasing concerns regarding water usage in mineral processing have led to a growing interest in dry jigging in recent years. However, there is still a need for a more comprehensive examination of the operational aspects of the technique. In this sense, this study focused on three main elements: (a) examining the air pulse pattern during dry jig operation; (b) assessing the evolution of the stratification profile over time using partition analysis; and (c) evaluating the specific energy consumption of batch dry jigging during operation. Also, an innovative operational strategy known as “transient pulsing” was proposed and analyzed, involving varying the intensity and frequency of the air pulse throughout the stratification process. All tests were conducted using density tracers spread across 11 density ranges (0.4–2.4 g/cm³) and a base bed (gravel) to analyze their separation in a batch, pilot-scale dry jig. Pressure drop and active power data were collected to measure the pulse characteristics and energy consumption. The airflow curves, obtained through pressure drop data, indicated that the pulsation process is more unstable as the airflow increases, possibly due to the pressure fluctuations experienced by air during valve closure. For the pulsation conditions used in the tests, the specific energy consumption was 10.66 Wh/kg of jigged material, with most of it related to the blower drive system. Analysis of the stratification evolution over time showed an oscillatory behavior, alternating between states of better (Ep < 0.1) and worse (Ep > 0.1) separation, especially for the near-gravity material (NGM). Results of the transient pulsation tests suggested that progressively increasing the vertical displacement of the bed during stratification resulted in slightly better segregation levels and more stable jigging evolution over time in comparison to stationary pulse conditions. Full article

This work investigates the dynamics of heavy particles dispersed in turbulent channel flows under unstable thermal stratification conditions using point-particle direct numerical simulations (PP-DNS), to quantify the influence of large-scale coherent vortex rolls, arising from the combined effects of shear and buoyancy, on the spatial distribution and preferential sampling behavior of inertial particles. We examined three particle Stokes numbers (${\mathrm{St}}^{+}=0.6,60,120$) and two friction Richardson numbers, ${\mathrm{Ri}}_{\tau }=0.272$ and ${\mathrm{Ri}}_{\tau }=27.2$, which exemplify the regimes below and above the critical condition for vortex roll formation, respectively. The results indicate that the flow reorganization into large-scale longitudinal vortices significantly alters the topological features of small scales in the near-wall region impinged by the thermal plumes, resulting in a prevalence of vorticity-dominated topologies. The interplay between this phenomenon and the tendency of particles to preferentially sample strain-dominated topologies leads to a distinctive asymmetric particle distribution in the near-wall planes. Inertial particles markedly accumulate in the strain-dominated regions where the coherent thermal plumes emerge from the walls, while avoiding the vorticity-dominated impingement zones. This peculiar particle response to the vortex rolls is most pronounced when the particle response time matches the characteristic timescale of the large-scale coherent motions in the cross-stream planes. Full article

Desmoid tumors (DTs) are non-metastasizing and locally aggressive soft-tissue mesenchymal neoplasms. Those that become enlarged often become locally invasive and cause significant morbidity. DTs have a varied pattern of clinical presentation, with up to 50–60% not growing after diagnosis and 20–30% shrinking or even disappearing after initial progression. Enlarging tumors are considered unstable and progressive. The management of symptomatic and enlarging DTs is challenging, and primarily consists of chemotherapy. Despite wide surgical resection, DTs carry a rate of local recurrence as high as 50%. There is a consensus that contrast-enhanced magnetic resonance imaging (MRI) or, alternatively, computerized tomography (CT) is the preferred modality for monitoring DTs. Each uses Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1), which measures the largest diameter on axial, sagittal, or coronal series. This approach, however, reportedly lacks accuracy in detecting response to therapy and fails to detect tumor progression, thus calling for more sophisticated methods. The objective of this study was to detect unique features identified by deep learning that correlate with the future clinical course of the disease. Between 2006 and 2019, 51 patients (mean age 41.22 ± 15.5 years) who had a tissue diagnosis of DT were included in this retrospective single-center study. Each had undergone at least three MRI examinations (including a pretreatment baseline study), and each was followed by orthopedic oncology specialists for a median of 38.83 months (IQR 44.38). Tumor segmentations were performed on a T2 fat-suppressed treatment-naive MRI sequence, after which the segmented lesion was extracted to a three-dimensional file together with its DICOM file and run through deep learning software. The results of the algorithm were then compared to clinical data collected from the patients’ medical files. There were 28 males (13 stable) and 23 females (15 stable) whose ages ranged from 19.07 to 83.33 years. The model was able to independently predict clinical progression as measured from the baseline MRI with an overall accuracy of 93% (93 ± 0.04) and ROC of 0.89 ± 0.08. Artificial intelligence may contribute to risk stratification and clinical decision-making in patients with DT by predicting which patients are likely to progress. Full article

We study electrohydrodynamic (EHD) linear (in)stability of microfluidic channel flows, i.e., the stability of interface between two shearing viscous (perfect) dielectrics exposed to an electric field in large aspect ratio microchannels. We then apply our results to particular microfluidic systems known as two-liquid electroosmotic (EO) pumps. Our novel results are detailed analytical expressions for the growth rate of two-dimensional EHD modes in Couette–Poiseuille flows in the limit of small Reynolds number (R); the expansions to both zeroth and first order in R are considered. The growth rates are complicated functions of viscosity-, height-, density-, and dielectric-constant ratio, as well as of wavenumbers and voltages. To make the results useful to experimentalists, e.g., for voltage-control EO pump operations, we also derive equations for the impending voltages of the neutral stability curves that divide stable from unstable regions in voltage–wavenumber stability diagrams. The voltage equations and the stability diagrams are given for all wavenumbers. We finally outline the flow regimes in which our first-order-R voltage corrections could potentially be experimentally measured. Our work gives insight into the coupling mechanism between electric field and shear flow in parallel-planes channel flows, correcting an analogous EHD expansion to small R from the literature. We also revisit the case of pure shear instability, when the first-order-R voltage correction equals zero, and replace the renowned instability mechanism due to viscosity stratification at small R with the mechanism due to discontinuity in the slope of the unperturbed velocity profile. Full article

Background: this study aimed to assess the complex relationship between EAT thickness, as measured with echocardiography, and the severity of coronary artery disease (CAD). We investigated whether individuals with higher EAT thickness underwent coronary revascularization. Subsequently, we conducted a three-year follow-up to explore any potential modifications in EAT depots post-angioplasty. Methods: we conducted a prospective and retrospective cross-sectional observational study involving 150 patients consecutively referred for acute coronary syndrome, including ST-elevation myocardial infarction (STEMI), non-ST elevation myocardial infarction (NSTEMI), and unstable angina. Upon admission (T0), all patients underwent coronary angiography to assess the number of pathologic coronary vessels. Percutaneous transluminal coronary angioplasty (PTCA) was performed based on angiogram results if indicated. The sample was categorized into two groups: non-revascularized (no-PTCA) and revascularized (PTCA). Transthoracic echocardiograms to measure epicardial fat thickness were conducted at admission (T0) and after a 3-year follow-up (T1). Results and conclusions: findings revealed a positive correlation between EAT thickness and the severity of coronary artery disease (CAD), with patients undergoing PTCA showing decreased EAT thickness after three years. Echocardiography demonstrated reliability in assessing EAT, offering potential for risk stratification. The study introduces a cut-off value of 0.65 cm as a diagnostic tool for cardiovascular risk. Incorporating EAT measurements into clinical practice may lead to more precise risk stratification and tailored treatment strategies, ultimately reducing the burden of cardiovascular disease. Full article

Rainstorms always occur in the southeast and northeast quadrants of the Northeast China Cold Vortex (NCCV), resulting in significant flooding. This study investigated water vapor and trigger mechanisms for rainstorms within these two regions of an NCCV event during 11–14 June 2022 in terms of Lagrangian backward tracking, stratification stability, and upward motion using the ERA5 reanalysis. In the mid-troposphere, a quasi-stationary “ridge-NCCV-ridge” pattern resided over northeastern China, with an “anticyclonic-cyclonic-anticyclonic” airflow in the lower troposphere. As a result, water vapor originated from the Yellow Sea and was transported in an “L” shape toward both two regions. The southeast region was influenced by southwesterly and northwesterly airflows, resulting in the convergence of moist air from the Yangtze River and Lake Baikal and significant vertical shear of positive vorticity advection. This dynamic created deep and pronounced upward currents in the southeast of the NCCV, leading to the development of intensive and extensive rainstorms in situ. In contrast, the northeast region of the NCCV was dominated by southerly airflow. The moist air converged against the lee side of the Great Khingan Mountains and generated shallow, unstable stratification. The upward motion in this area was relatively weaker and thus induced regional rainstorms. Full article