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Selecting appropriate governing equations for fluid flow in fractured rock masses is of special importance for estimating the permeability of rock fracture networks. When the flow velocity is small, the flow is in the linear regime and obeys the cubic law, whereas when the flow velocity is large, the flow is in the nonlinear regime and should be simulated by solving the complex Navier-Stokes equations. The critical conditions such as critical Reynolds number and critical hydraulic gradient are commonly defined in the previous works to quantify the onset of nonlinear fluid flow. This study reviews the simplifications of governing equations from the Navier-Stokes equations, Stokes equation, and Reynold equation to the cubic law and reviews the evolutions of critical Reynolds number and critical hydraulic gradient for fluid flow in rock fractures and fracture networks, considering the influences of shear displacement, normal stress and/or confining pressure, fracture surface roughness, aperture, and number of intersections. This review provides a reference for the engineers and hydrogeologists especially the beginners to thoroughly understand the nonlinear flow regimes/mechanisms within complex fractured rock masses.

Active or semi-active vibration control systems require real-time vibration information from controlled structures as feedback. However, integrating vibration sensors into some controlled structures remains a challenge due to factors such as mass and signal lines. This issue is particularly prominent in attachment structures located far from the spacecraft, such as robotic arms and solar panels. This paper presents a miniaturized autonomous inertial sensor that can be easily attached to the controlled structure to acquire vibration data and wirelessly transmit the data. We also establish the relationship between cantilevered structural vibration and the inertial acceleration or angular velocity directly measured by the sensor. Consequently, the feedback information for the control system can be calculated by the processor in real-time. This autonomous inertial sensor consists of an inertial measurement unit (IMU) named BMI088 and a common wireless communication unit. An improved Extended Kalman Filter (EKF) algorithm is employed to enhance the quality of the sensing data in practical environments. The experimental results validated the theoretical model, indicating that the miniaturized inertial sensor effectively captures the bending vibration characteristics of the controlled structure.

A sound knowledge of the transmissivity of rock fractures is of special importance to the fields of mining, CO2 sequestration, underground oil storage. and contaminant containment. For fluid flow in fractured rock masses, it is commonly assumed that the transmissivity of fractures is much larger than that of the rock matrix and that flow in fractures follows the cubic law, in which the flow rate is linearly correlated with the pressure drop.

Enhancing convective heat transfer efficiency in waste heat recovery applications is critical for improved energy utilization. This study conducts a convective heat transfer optimization of a tube bundle for waste heat recovery of flue gas based on an exergy destruction minimization method. The results indicate that the multi-longitudinal vortex flow is the optimal flow field for heat transfer in a tube bundle. To achieve this flow field, a novel tube bundle equipped with symmetrically inclined annular fins has been proposed and the thermal–hydraulic performance has been numerically investigated. The effects of key geometric parameters, including fin inclination angle (θ = 30°, 35°, 40°, 45°, 50°) and fin diameters (D = 62, 68, 74 mm), were systematically analyzed under varying inlet velocities (8–16 m/s) and heat flux densities (23,000–49,000 W/m2) at inlet temperatures of 527 K and 557 K. Results demonstrate that both the convective heat transfer coefficient (h) and tube bundle power consumption (Pw) increase with rising fin diameters and inclination angle. At a constant D, h and Pw exhibit a positive correlation with θ. Crucially, compared to a traditional smooth-tube bundle, the optimal annular fin configuration (θ = 45°, D = 74 mm) achieved a significant enhancement in the convective heat transfer coefficient of 22.76% to 31.22%. This improvement is attributed to intensified vortex generation near the fins, particularly above and below them at higher angles, despite a reduction in vortex count. These findings provide valuable insights for the design of high-efficiency finned tube heat exchangers for flue gas waste heat recovery.

Background Although tumor cell heterogeneity between the tumor center (TC) and invasion front (IF) of oral squamous cell carcinoma (OSCC) is well documented, the morphological, molecular, and functional characteristics of cancer-associated fibroblasts (CAFs) in these regions remain poorly understood. Methods We examined hematoxylin and eosin (H&E)–stained OSCC sections to assess CAF morphology and correlation with patient prognosis. We then isolated paired CAFs from the tumor center (CAF TC ) and invasion front (CAF IF ) of four OSCC patients and compared their ECM-remodeling activity and pro-tumorigenic effects on OSCC cells. Furthermore, RNA sequencing identified differentially expressed genes between CAF TC and CAF IF . Finally, based on RNA-seq findings, we knocked down hyaluronan synthase 1 (HAS1) in CAF IF to evaluate its role in extracellular matrix (ECM) remodeling and tumor invasion. Results Compared to CAF TC , CAF IF exhibited a plump cell morphology and were associated with shorter disease-free survival. Functionally, CAF IF showed higher ECM-remodeling activity and more effective ability for promoting OSCC invasion and lymph node metastasis than CAF TC . RNA-seq identified HAS1 was significantly upregulated in CAF IF , promoting hyaluronic acid (HA) production and ECM remodeling. HAS1 knockdown in CAF IF diminished ECM remodeling and attenuated the ability of CAF IF to promoting OSCC invasion. Conclusion CAF IF with plump cell morphology showed pro-invasive abilities, driven in part by HAS1 overexpression and ECM remodeling, suggesting that targeting HAS1-driven ECM remodeling could be a promising therapeutic strategy.

An 18-year-old Chinese woman presented with chief complaints of crowded teeth and mild mandibular prognathism. Clinical and imaging examinations revealed a concave profile, a protruded chin, increased lower anterior facial height mild, skeletal Class III and Angle’s Class III malocclusion, with anterior crossbites, and crowded teeth. Extraction camouflaged therapy combined with miniscrews skeletal anchorage was employed to relieve crowding and retract the mandibular anterior teeth. The total active treatment time was 31 months. After treatment, functional occlusion and smile esthetics were significantly improved.

Cleft lip and palate is a congenital craniofacial anomaly that affects the lip and oral cavity. The management and orthodontic treatment of this anomaly is important but challenging. This article reports the successful treatment of a patient with bilateral cleft lip and palate, Class III malocclusion, bilateral crossbite, crowding and microdontic maxillary lateral incisors. One mandible incisor was extracted, and three miniscrew anchorages were utilized to distalize the maxillary left dental arch and retract the mandibular arch. After treatment, ideal occlusion and a better profile were established, and long-term stability was confirmed by a 4-year follow-up. This article represents a successful attempt of orthodontic camouflage treatment of severe dentofacial discrepancy, as an important part of the series treatment of cleft lip and palate, to provide some insight into the clinical field.

Human adipose-derived stem cells (hASCs) are a promising cell type for bone tissue regeneration. Circular RNAs (circRNAs) have been shown to play a critical role in regulating various cell differentiation and involve in mesenchymal stem cell osteogenesis. However, how circRNAs regulate hASCs in osteogenesis is still unclear. Herein, we found circ_0003204 was significantly downregulated during osteogenic differentiation of hASCs. Knockdown of circ_0003204 by siRNA or overexpression by lentivirus confirmed circ_0003204 could negatively regulate the osteogenic differentiation of hASCs. We performed dual-luciferase reporting assay and rescue experiments to verify circ_0003204 regulated osteogenic differentiation via sponging miR-370-3p. We predicted and confirmed that miR-370-3p had targets in the 3′-UTR of HDAC4 mRNA. The following rescue experiments indicated that circ_0003204 regulated the osteogenic differentiation of hASCs via miR-370-3p/HDAC4 axis. Subsequent in vivo experiments showed the silencing of circ_0003204 increased the bone formation and promoted the expression of osteogenic-related proteins in a mouse bone defect model, while overexpression of circ_0003204 inhibited bone defect repair. Our findings indicated that circ_0003204 might be a promising target to promote the efficacy of hASCs in repairing bone defects.

Purpose Intraoperative blood transfusion is associated with adverse events. We aimed to establish a machine learning model to predict the probability of intraoperative blood transfusion during intracranial aneurysm surgery. Methods Patients, who underwent intracranial aneurysm surgery in our hospital between January 2019 and December 2021 were enrolled. Four machine learning models were benchmarked and the best learning model was used to establish the nomogram, before conducting a discriminative assessment. Results A total of 375 patients were included for analysis in this model, among whom 108 received an intraoperative blood transfusion during the intracranial aneurysm surgery. The least absolute shrinkage selection operator identified six preoperative relative factors: hemoglobin, platelet, D-dimer, sex, white blood cell, and aneurysm rupture before surgery. Performance evaluation of the classification error demonstrated the following: K-nearest neighbor, 0.2903; logistic regression, 0.2290; ranger, 0.2518; and extremely gradient boosting model, 0.2632. A nomogram based on a logistic regression algorithm was established using the above six parameters. The AUC values of the nomogram were 0.828 (0.775, 0.881) and 0.796 (0.710, 0.882) in the development and validation groups, respectively. Conclusions Machine learning algorithms present a good performance evaluation of intraoperative blood transfusion. The nomogram established using a logistic regression algorithm showed a good discriminative ability to predict intraoperative blood transfusion during aneurysm surgery.

Background Many clinical studies have shown a correlation between proton pump inhibitors (PPIs) and osteoporosis or fractures. The purpose of this study was to establish a murine model of chronic oral PPI administration to verify whether PPIs caused bone metabolic impairment and investigate the relevant molecular mechanism underlying the effects of PPIs on MC3T3-E1 murine osteoblasts. Methods A lansoprazole-induced bone loss model was used to investigate the damaging effects of PPIs. In vivo, immunohistochemistry, Hematoxylin–Eosin (HE) staining, micro-CT analysis, and blood biochemical analyses were used to evaluate the effect of lansoprazole on bone injury in mice. In vitro, the effects of lansoprazole and related signaling pathways in MC3T3-E1 cells were investigated by CCK-8 assays, EdU assays, flow cytometry, laser confocal microscopy, patch clamping, reverse transcription-quantitative polymerase chain reaction and Western blotting. Results After 6 months of lansoprazole gavage in ICR mice, the micro-CT results showed that compared with that in the vehicle group, the bone mineral density (BMD) in the high-dose group was significantly decreased ( P  < 0.05), and the bone microarchitecture gradually degraded. Biochemical analysis of bone serum showed that blood calcium and phosphorus were both decreased ( P  < 0.01). We found that long-term administration of lansoprazole impaired skeletal function in mice. In vitro, we found that lansoprazole (LPZ) could cause calcium overload in MC3T3-E1 cells leading to apoptosis, and 2-APB, an inhibitor of IP3R calcium release channel and SOCE pathway, effectively blocked increase in calcium caused by LPZ, thus protecting cell viability. Conclusions Longterm administration of LPZ induced osteoporotic symptoms in mice, and LPZ triggered calcium increases in osteoblasts in a concentration-dependent manner. Intracellular calcium ([Ca 2+ ] i ) persisted at a high concentration, thereby causing endoplasmic reticulum stress (ERS) and inducing osteoblast apoptosis.