Search Results (27,958)

Spigelian hernia (SH) is an infrequent aponeurotic defect in Spiegel’s semilunar line. The literature on pediatric SH is scarce. A comprehensive review of the previous literature was conducted. Eligible studies were identified by searching primary medical bibliography databases, and a pooled analysis of published case-level data was performed. Medians and interquartile ranges were used to describe the quantitative variables and proportions for categorical variables. The Kruskal–Wallis, Mann–Whitney U, and Fisher’s exact tests were used to compare group variables. Spearman’s and Pearson’s correlation analyses were used to assess the degree of correlation between variables, while Cramér’s V was applied to evaluate the degree of association among the variables. A p-value < 0.05 (two-tailed) was considered statistically significant. Our search identified 82 publications reporting on 123 patients (106 male, 86.2%), with an age range of 0–21 years. Forty-seven patients (38.2%) had a left-sided SH, fifty-six (45.5%) had a right-sided SH, and thirteen (10.6%) had a bilateral SH. Traumatic SH, mostly from bicycle injuries, accounted for 45 cases (36.6%), while 41 (33.3%) were associated with undescended testis (UDT). In this series of published cases, hernia incarceration/strangulation (I/S) was reported in 15 patients (12.2%), who were significantly younger (p = 0.02). Surgical correction was performed in 95 cases (77.2%), 14 of them laparoscopically, with a 35.7% conversion rate. Eight cases (6.5%) were managed conservatively. Overall, outcomes were favorable. SH is an infrequent pediatric condition that, based on the synthesized literature, predominantly affects males. The published cases suggest two main clinical phenotypes: a congenital form, often linked to ipsilateral UDT, and an acquired form, typically resulting from trauma. Analysis of the reported data indicates a higher risk of incarceration in early childhood. Surgical treatment is the most frequently reported approach with generally favorable outcomes, whereas the evidence for conservative management remains limited. This comprehensive review highlights the dual nature of pediatric SH and underscores the need for a high index of suspicion in relevant clinical scenarios. Full article

This study presents an analytical model to reduce the impact of wave-induced forces on a vertical seawall by introducing a floating elastic plate (EP) located at a specific distance from two bottom-standing porous structures (BSPs). The hydrodynamic interaction with the EP is described using thin plate theory, while the fluid flow through the porous medium is described by the model developed by Sollit and Cross. The resulting boundary value problem is addressed through linear potential theory combined with the eigenfunction expansion method (EEM), and model validation is achieved through consistency checks with recognized results from the literature. A comprehensive parametric analysis is performed to evaluate the influence of key system parameters such as the porosity and frictional coefficient of the BSPs, their height and width, the flexural rigidity of the EP, and the spacing between the EP and BSPs on vital hydrodynamic coefficients, including the wave force on the seawall, free surface elevation, wave reflection coefficient, and energy dissipation coefficient. The results indicate that higher frictional coefficients and higher BSP heights significantly enhance wave energy dissipation and reduce reflection, in accordance with the principle of energy conservation. Oscillatory trends observed with respect to wavenumbers in the reflection and dissipation coefficients highlight resonant interactions between the structures. Moreover, compared with a single BSP, the double BSP arrangement is more effective in minimizing the wave force on the seawall and free surface elevation in the region between the EP and the wall, even when the total volume of porous material remains unchanged. The inter-structural gap is found to play a crucial role in optimizing resonance conditions and supporting the formation of a tranquility zone. Overall, the proposed configuration demonstrates significant potential for coastal protection, offering a practical and effective solution for reducing wave loads on marine infrastructure. Full article

High viscosity of alginate means a relatively low substrate concentration, which limits the efficiency of hydrolysis, resulting in one of the main challenges for the large-scale production of alginate oligosaccharides (AOS). In this study, a pilot-scale degradation product (PSDP) of the recombinant enzyme 102C300C-Vgb was produced for the first time at a substrate concentration of up to 20% sodium alginate. The optimal conditions for SA digestion were: enzyme dosage of 25 U/g, enzymatic temperature of 45 °C, enzymatic pH of 7.0, and enzymatic time of 24 h. Under these conditions, the yield of enzymatic hydrolysis was consistently in the range of 69% to 70%. The average molecular weight (Mw) of PSDP was 1496.36 Da, mainly containing oligosaccharides with degrees of polymerization ranging from 2 to 4. The low-Mw PSDP was subsequently applied in the diet of sea cucumber Stichopus japonicus. The results showed that the body wall weight of S. japonicus increased significantly after 40 days of feeding with a 0.09% PSDP-supplemented diet. Furthermore, PSDP-supplemented diet significantly increased the thickness of the serosal and submucosal layers and the width folds of mucosa of the sea cucumber gut. The abundance of pathogenic bacteria was reduced effectively, and that of beneficial bacteria increased significantly after being fed with PSDP. The results demonstrated that PSDP can serve as a digestive health enhancer for sea cucumbers, promoting their healthy growth. Full article

With the increasing demand for urban rail transit capacity, shield tunneling has become the predominant method for constructing underground metro systems in densely populated cities. However, the spatial interaction between shield tunnels and adjacent retaining structures poses significant engineering challenges, potentially leading to excessive ground settlement, structural deformation, and even stability failure. This study systematically investigates the deformation behavior and associated risks of retaining systems during adjacent shield tunnel construction. An orthogonal multi-factor analysis was conducted to evaluate the effects of grouting pressure, grout stiffness, and overlying soil properties on maximum surface settlement. Results show that soil cohesion and grouting pressure are the most influential parameters, jointly accounting for over 72% of the variance in settlement response. Based on the numerical findings, a Bayesian network model was developed to assess construction risk, integrating expert judgment and field monitoring data to quantify the conditional probability of deformation-induced failure. The model identifies key risk sources such as geological variability, groundwater instability, shield steering correction, segmental lining quality, and site construction management. Furthermore, the effectiveness and cost-efficiency of various grouting reinforcement strategies were evaluated. The results show that top grouting increases the reinforcement efficiency to 34.7%, offering the best performance in terms of both settlement control and economic benefit. Sidewall grouting yields an efficiency of approximately 30.2%, while invert grouting shows limited effectiveness, with an efficiency of only 11.6%, making it the least favorable option in terms of both technical and economic considerations. This research provides both practical guidance and theoretical insight for risk-informed shield tunneling design and management in complex urban environments. Full article

Excessive stress disrupts cardiac homeostasis via complex and multifactorial mechanisms, resulting in cardiac dysfunction, cardiovascular disease, or even sudden cardiac death, yet the underlying molecular mechanisms remain poorly understood. Accordingly, we aimed to elucidate how stress induces calcium dysregulation and contributes to cardiac dysfunction and injury through the nuclear receptor subfamily 3 group c member 1 (NR3C1)/Glomulin (GLMN)/FK506-binding protein 12.6 (FKBP12.6) signaling pathway. Using mouse models of acute and chronic restraint stress, we observed that stress-exposed mice exhibited reduced left ventricular ejection fraction, ventricular wall thickening, elevated serum and myocardial cTnI levels, along with pathological features of myocardial ischemia and hypoxia, through morphological, functional, and hormonal assessments. Using transmission electron microscopy and Western blotting, we found that stress disrupted mitochondrial quality control in cardiomyocytes, evidenced by progressive mitochondrial swelling, cristae rupture, decreased expression of fusion proteins (MFN1/OPA1) and biogenesis regulator PGC-1α, along with aberrant accumulation of fission protein (FIS1) and autophagy marker LC3. At the cellular level, ChIP-qPCR and siRNA knockdown confirmed that stress activates the glucocorticoid receptor NR3C1 to repress its downstream target GLMN, thereby preventing FKBP12.6 ubiquitination and degradation, resulting in calcium leakage and overload, which ultimately impairs mitochondrial quality control and damages cardiomyocytes. In conclusion, our findings reveal that stress induces myocardial damage through NR3C1/GLMN-mediated FKBP12.6 ubiquitination, disrupting calcium homeostasis and mitochondrial quality control, and lay a theoretical foundation for dissecting the intricate molecular network of stress-induced cardiomyopathy. Full article

Urban planning in arid climates must overcome numerous nonclimatic constraints that often result in outdoor thermal discomfort. This is particularly evident in Béchar, a city in southern Algeria known for its long, intense summers with temperatures frequently exceeding 45 °C. This study investigates the influence of urban morphology on thermal comfort and explores architectural and digital solutions to enhance energy performance in buildings. This research focuses on Béchar’s city center, where various urban configurations were analyzed using a multidisciplinary approach that combines typomorphological and climatic analysis with numerical simulations (ENVI-met 3.0 and TRNSYS 16). The results show that shaded zones near buildings have lower thermal loads (under +20 W/m²), while open areas may reach +100 W/m². The thermal comfort rate varies between 22% and 60%, depending on wall materials and occupancy patterns. High thermal inertia materials, such as stone and compressed stabilized earth blocks (CSEBs), reduce hot discomfort hours to under 1700 h/year but may increase cold discomfort. Combining these materials with targeted insulation improves thermal balance. Key recommendations include compact urban forms, vegetation, shading devices, and high-performance envelopes. Early integration of these strategies can significantly enhance thermal comfort and reduce energy demand in Saharan cities. Full article

Background and Objectives: Ureteral kinking may hinder endoscopic access and reduce the success of ureteroscopic lithotripsy (URSL). This study evaluated whether kinking can be predicted preoperatively using non-contrast computed tomography (CT) by introducing a novel metric—Maximum Horizontal Ureteral Displacement (HUDmax)—and assessed its predictive value for procedural success. Materials and Methods: Data from 1261 patients who underwent URSL for a single ureteral stone were retrospectively analyzed. Patients were categorized into two groups based on whether the stone could be reached using a semirigid ureteroscope. Propensity score matching (1:2) was performed based on stone size and location, resulting in two matched cohorts: Group 1—Semirigid Inaccessible (SRI, n = 72), and Group 2—Semirigid Accessible (SRA, n = 144). Stone characteristics, ureteral wall thickness (UWT), and HUDmax were evaluated. Correlations between HUDmax and surgical parameters were analyzed, and the predictive value of HUDmax was assessed using receiver operating characteristic (ROC) analysis. Results: The SRI group showed significantly higher HUDmax values (median 2.36 mm vs. 1.2 mm, p < 0.0001). Semirigid access failure necessitated conversion to flexible ureteroscopy in all SRI cases, compared to 15% in the SRA group (p < 0.0001). Stone-free rates were significantly lower in the SRI group (45% vs. 82%, p < 0.0001), and the use of a double-J stent or nephrostomy placement was more frequent. Operative times were also longer in the SRI group (55 vs. 42 min, p < 0.0001). HUDmax correlated positively with operative time (r = 0.258, p = 0.005) but not with stone size, density, UWT, or hydronephrosis. ROC analysis showed HUDmax strongly predicted semirigid access failure (AUC: 0.805; cutoff: 1.58 mm), and moderately predicted stone-free status (AUC: 0.697; cutoff: 1.68 mm). Conclusions: Severe ureteral kinking constitutes a significant anatomical obstacle to the success of semirigid URSL. This study is the first to demonstrate that clinically relevant kinking can be predicted preoperatively using a non-contrast imaging modality, via the novel HUDmax parameter. Full article

The transport behavior of particles in tortuous fractures is prevalent in the oil and gas extraction process and has a profound impact on engineering. However, due to a variety of factors, drilling fluid leakage is prone to occur during drilling and completion, and an evaluation system for the influence of meander characteristics on the kinetic properties of particles has not yet been established. To this end, this paper constructs a numerical model based on CFD-DEM numerical simulation to simulate the particle–fluid two-phase flow in the meandering fracture, investigates the mechanism of surface meandering on particle force, particle transport velocity, and particle residence time, and proposes a mathematical method based on meandering for predicting particle transport velocity and particle residence time in the stable transport phase. The results show that the increase in tortuosity makes the force state of particles in the fracture show significant instability and intensifies the interaction between fluid and particles in the fracture; the effect of the tortuous wall intensifies the inhomogeneity of transport velocity, and the perturbation effect of the complex path structure on the x-direction velocity of particles is stronger; and the increase in tortuosity is not conducive to particle retention in the fracture. The results of the study can provide theoretical guidance for reducing the risk of drilling fluid leakage during drilling and completion. Full article

In order to explore new wall panel materials and structural systems suitable for prefabricated buildings, this study proposes a polypropylene fiber-reinforced concrete sandwich wall panel (PFRC sandwich wall panel) and a polypropylene fiber-reinforced concrete sandwich wall panel with glass fiber grid (G-PFRC sandwich wall panel). A comparative investigation was conducted using finite element analysis to numerically simulate the mechanical response of these composite wall panels under impact loads. The simulation results were compared with those of an unreinforced concrete sandwich wall panel with glass fiber grid (G-UC sandwich wall panel). Key findings include: (1) Compared with the G-UC sandwich wall panel, the G-PFRC sandwich wall panel exhibited 19.3% lower peak deformation and 23.7% reduced residual deformation; (2) Relative to the standard PFRC sandwich wall panel, the G-PFRC sandwich wall panel demonstrated 16.5% smaller peak deformation and 27.9% less residual deformation under impact loads; (3) Damage analysis revealed that the G-PFRC sandwich wall panel developed fewer cracks with lower damage severity compared to both the PFRC and G-UC sandwich wall panels. Parametric studies further indicated that the G-PFRC sandwich wall panel maintains superior deformation resistance and impact performance across varying impact heights and impact masses. The synergistic combination of polypropylene fiber with a glass fiber grid significantly enhances the impact resistance of composite sandwich panels, providing valuable theoretical insights for engineering applications of these novel wall systems in prefabricated construction. Full article

An internal geomembrane (GMB)–clay seepage control system is an important form of seepage control structure for rockfill dams. In order to investigate the stress and deformation characteristics of GMB in GMB–clay core-wall rockfill dams (GMCWRD) under different construction and operation conditions, the stress and deformation fields of GMCWRDs were calculated by numerical simulation under a variety of working conditions. The stress and deformation characteristics of the dam and GMB during the impoundment period were investigated, and the influences of the spreading thickness of the clay core-wall and the location of the GMB defects and hydraulic head on the stress and deformation of the GMB were analyzed. The results show that the maximum tensile strain of the GMB upstream of the clay core-wall during the impoundment period occurs at the anchorage of the GMB and the concrete cut-off, with a maximum tensile strain of 2.70%. With the increase in the spreading thickness of the clay core-wall, the maximum tensile stress and strain of the GMB fluctuated. Under the dam construction and foundation conditions in this paper, when the spreading thickness of the clay core-wall was 2 m, the tensile stress and strain of GMB were at the lowest level. As the defect location of the GMB decreases, the phreatic line of the dam gradually increases, and the seepage discharge of the dam and the tensile strain of the GMB gradually increase, with the maximum tensile strain of 3.98%. The maximum deformation of the GMB in each case is much smaller than the maximum elastic deformation range of the selected PVC GMB, and the conclusion of the study provides a certain scientific basis for the design and construction of the seepage control of the core rockfill dam. Full article

To meet the requirements of a prefabricated building with specific strength limitations and assembly rate criteria, the research proposes a Low-Strength Foamed Concrete Cold-Formed Steel (CFS) Framing Composite Enclosure Wall Panel (LFSW). The ABAQUS 2024 finite element analysis (FEA) combined with bending performance tests on five specimens were employed to examine crack propagation and failure modes of wall panels under wind load, investigating the influence mechanisms of foamed concrete strength, CFS framing wall thickness, CFS framing section height, and concrete cover thickness on the flexural performance of wall panels. The experimental results demonstrate that increasing the steel thickness from 1.8 mm to 2.5 mm enhances the ultimate load-carrying capacity by 46.15%, while enlarging the section height from 80 mm to 100 mm improves capacity by 26.67%. When the foamed concrete strength increased from 0.5 MPa to 1.0 MPa, the wall panel cracking load increased by 50%, while the ultimate load capacity changed by less than 5%. Increasing the concrete cover thickness from 25 mm to 35 mm enhanced the ultimate capacity by 7%, indicating that both parameters exert limited influence on the composite wall panel’s flexural capacity. Finite element simulations demonstrate excellent agreement with experimental results, confirming effective composite action between foamed concrete and CFS framing under service conditions. This validation establishes that the simplified analytical model neglecting interface slip provides better accuracy for engineering design, offering theoretical foundations and practical references for optimizing prefabricated building envelope systems. Full article

Film-cooling holes are the key cooling structures of turbine blades, and there are still great challenges in manufacturing high-quality film-cooling holes. Although abrasive flow machining can be used as a post-processing technique to optimize the quality of film-cooling holes, its action process and influence mechanism have not been systematically studied. Herein, the drilling method of femtosecond laser combined with abrasive flow is studied in detail. Moreover, for comparison, the drilling methods of single femtosecond laser, single electrical discharge machining, and electrical discharge machining combined with abrasive flow are also discussed. The microstructure and composition distribution of the hole walls before and after abrasive flow machining were systematically characterized, indicating that abrasive flow can effectively remove the recast layer and cause local plastic deformation. Due to the surface hardening and non-uniform residual stress caused by abrasive impact, abrasive flow machining can increase the high-temperature endurance time of film-cooling holes while reducing the elongation. The combination of femtosecond laser and abrasive flow machining demonstrates the best high-temperature mechanical properties, with the endurance time and elongation reaching 136.15 h and 12.1%, respectively. The fracture mechanisms of different drilling methods are further discussed in detail. The research results provide theoretical guidance for the manufacturing of high-quality film-cooling holes through the composite processing of femtosecond laser and abrasive flow. Full article

Background: Hereditary transthyretin amyloidosis (ATTRv) is a rare, autosomal dominant multisystem disease caused by pathogenic variants in the transthyretin (TTR) gene. Although ATTRv is classically categorized into “cardiac” and “neurologic” phenotypes, recent evidence suggests a more complex and overlapping disease spectrum. Objectives: This study investigates the relationship between neurological staging and cardiac involvement through an integrated assessment of patients with confirmed TTR mutations. Methods and Results: Fifty-eight patients with genetically confirmed ATTRv (41% female, mean age 60 ± 15 years) were evaluated. Genotypes included Phe64Leu, Val30Met, Val122Ile, and others. Patients were stratified by neurological stage: G0 (asymptomatic carriers), G1 (symptomatic but ambulatory), and G2 (requiring walking support). Cardiac assessment included clinical evaluation, echocardiography with tissue Doppler, global longitudinal strain (GLS), and NT-proBNP levels. Cardiac markers worsened with neurological stage. NT-proBNP, left ventricular mass index, maximal wall thickness, and E/E′ ratio increased progressively, while GLS declined (G0: –19%, G1: –14%, G2: –13%; p < 0.001), indicating a progressive structural and functional myocardial disease. Ejection fraction remained preserved. Neurological stage independently predicted cardiac dysfunction after age adjustment. Conclusions: This is the first study to assess cardiac abnormalities across neurological stages in a well-characterized cohort of ATTRv patients. Cardiac involvement in ATTRv begins early, even in asymptomatic carriers, and progresses with neurological deterioration. GLS and diastolic parameters are sensitive indicators of early myocardial dysfunction, highlighting the need for integrated neurologic and cardiac monitoring in all patients with ATTRv, regardless of initial phenotype. Full article

The use of single-layer aerated concrete walls in residential construction has a tradition of over 60 years. Its main advantage is thermal insulation. It is the most advantageous among construction materials used for the construction of external walls. The possibility of modifying the dimensions of the blocks leads to meeting subsequent restrictive values of the heat transfer coefficient U. The high dimensional accuracy of the blocks allows the use of dry vertical joints and thin joints with a thickness of 1–3 mm, the thermal influence of which is omitted. However, the thermal uniformity of such a wall is strictly dependent on the quality of workmanship. The main objective of the analysis is to assess the impact of moisture on the U_wall of walls as a function of vertical joint spacing and horizontal joint thickness. It should be said that the effect of humidity and manufacturing accuracy on the thermal properties of aerated concrete walls has not been sufficiently studied. Further study of these patterns is necessary. Particular attention should be paid to the thin-bed mortar, which depends on the manufacturing accuracy. The separation of AAC masonry elements that occurs during bricklaying significantly affects the thermal insulation of walls. This issue has not yet been analysed. The scientific objective of this article is to develop a procedure for determining the thermal properties of a small, irregular air space created as a result of the separation of masonry elements and the impact of this separation on the thermal insulation of the wall. Based on the analysis of the thermal conductivity of voids and masonry elements, it was determined that this impact is visible at low AAC densities. A detailed analysis taking into account both these joints and horizontal joints, as well as different moisture levels, made it possible to determine the permissible separation of AAC blocks, at which the high thermal insulation requirements applicable in most European countries are met. The analysis showed that it is possible to meet the thermal protection requirements for 42 cm wide blocks intended for single-layer walls with a maximum vertical contact width of 3 mm and a joint thickness of up to 2 mm. AAC moisture content plays a major role in thermal insulation. Insulation requirements can be met for AAC in an air-dry state, as specified by ISO 10456. Full article

Tomato brown rugose fruit virus (ToBRFV) has been causing severe agricultural damage worldwide since its recent discovery. While related to tobacco mosaic virus, its properties and infection mechanisms are poorly understood. To uncover their structure and nanomechanics, we carried out atomic force microscopy (AFM) measurements on individual ToBRFV particles. The virions are rod-shaped with a height and width of 9 and 30 nm, respectively. Length is widely distributed (5–1000 nm), with a mode at 30 nm. ToBRFV rods displayed a 22.4 nm axial periodicity related to structural units. Force spectroscopy revealed a Young’s modulus of 8.7 MPa, a spring constant of 0.25 N/m, and a rupture force of 1.7 nN. In the force curves a step was seen at a height of 3.3 nm, which is related to virion wall thickness. Wall thickness was also estimated by predicting coat protein structure with AlphaFold, yielding a protein with a length of 7.3 nm. Accordingly, the structural element of ToBRFv is a right circular cylinder with an equal height and diameter of ~22 nm and a wall thickness between 3.3 and 7.3 nm. Thus, at least four to nine serially linked units are required to encapsidate a single, helically organized RNA genome. Fragmentation of ToBRFV into these cylindrical structural units may result in a facilitated release of the genome and thus efficient infection. Full article