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Silica aerogel (SA) was synthesized through the sol-gel process followed by ambient pressure drying, with aluminum-deposited silica aerogel (ASA) subsequently produced via aluminum deposition using an AlCl3·6H2O hydrolysis solution. This study examined the impact of deposition time and calcination temperature on ASA's characteristics. Compared to the non-aluminum-deposited SA, ASA with 12 h of deposition time (ASA-12h) showcased a significant increase in specific surface area, reaching 675m2 ∙ g−1 at room temperature. Post-calcination at 800 °C and 1000 °C resulted in specific surface areas of 613m2 ∙ g−1 and 265m2 ∙ g−1, respectively, markedly surpassing those of SA (240 m2∙g−1 at 800 °C and 16m2 ∙ g−1 at 1000 °C). The results demonstrate that during the aging process, the deposited aluminum is coated by the aging solution, enabling it to remain stable and distribute uniformly. This deposition not only increases the particle size but also enhances structural stability. Furthermore, the formation of new Si-O-Al bonds improves the thermal stability of the silicon dioxide lattices. These insights pave the way for the industrial production of aerogels that are resistant to high temperatures. Highlights: The production cost was reduced by using acidic silica sol and TEOS as composite silicon sources. The aluminum element is uniformly and stably distributed in the SiO2 aerogel skeleton by the method of alumina deposition. The high-temperature resistance of aerogel was improved obviously after alumina deposition. [ABSTRACT FROM AUTHOR]

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Bluff-body wakes generally become three-dimensional (3-D) and then turbulent when the Reynolds number exceeds a few hundred. Other than an alternate shedding of the spanwise vortices behind the body and a gradual decay and annihilation of the vortices with distance downstream, whether a secondary vortex street would develop in the relatively far wake has been a long-standing argument in the literature. This argument is addressed in the present study. Specifically, direct numerical simulations and transient growth analysis are performed to examine the two-dimensional and 3-D wakes of different bluff bodies, including circular cylinder, square cylinder, diamond cylinder and rectangular cylinders with different cross-sectional aspect ratios. We found that a secondary vortex street is absent for most 3-D and turbulent wakes. The root cause is the weakening of spanwise vortices by 3-D wake instability modes and streamwise circulation/vorticity. The weakened spanwise vortices induce reduced mean shear in the intermediate wake, which then induces much smaller perturbation energy growth that is below the threshold for the emergence of a secondary vortex street. This finding suggests that the 3-D and turbulence characteristics, and the momentum, mass and heat transport in the relatively far wake of bluff bodies, would not be influenced by extra anisotropy or inhomogeneity caused by a secondary vortex street. [ABSTRACT FROM AUTHOR]

To reduce production costs and enhance the high-temperature resistance of SiO2 aerogels, an aluminum-doped silica aerogel (ASA) was successfully prepared using the sol-gel method and atmospheric drying method. The composite silica sources included TEOS and inexpensive acidic silica sol, while the aluminum source was aluminum sol. The study investigated the influence of the molar ratio of acidic silica sol to TEOS, Al/Si, and calcination temperature on the composition, structure, and high-temperature resistance of the ASA. The results indicate that a sample with an acidic silica sol to TEOS molar ratio of 0.8 achieved a specific surface area of 683.204 m2·g−1. The Al/Si molar ratio significantly impacted the high-temperature resistance of the ASA, with the sample having a molar ratio of 0.02 Al/Si displaying the highest specific surface area of 705.956 m2·g−1 at 600 °C. Moreover, this surface area remained at 273.099 m2·g−1 after calcination at 1000 °C, notably higher than the sample without aluminum sol (16.082 m2·g−1). Mechanism analysis indicated that the addition of aluminum sol to the SiO2 aerogel inhibited phase transitions, and both acidic silica sol and aluminum sol particles enhanced the aerogel structure, contributing to a marked improvement in high-temperature resistance. [ABSTRACT FROM AUTHOR]

The canonical scenario of cross-flow vortex-induced vibration (VIV) of a circular cylinder in the turbulent regime, which has been studied by several physical experiments in the literature, is reexamined in this study through high-fidelity large-eddy simulations (LES) at a Reynolds number 104. The VIV response (including vibration amplitude and frequency) and hydrodynamic coefficients predicted by the present LES agree with the experimental results better than previous numerical attempts. In addition, several phenomena reported by previous experimental studies are confirmed numerically for the first time. After validating against the experiments, new VIV characteristics and physical mechanisms are explored with confidence. First, a collective analysis on the frequency spectra of the displacement, lift, and velocity signals provides a complete picture of the frequency response of the system. In contrast, the use of a single signal may miss certain aspects of the frequency response, so that caution should be exercised. Second, spanwise correlation of primary vortex shedding is examined, where relatively low correlations in the upper and lower branches are likely because the vortex shedding patterns involve complex vortex generation and interaction. Third, the effect of mass ratio (m*) of the cylinder on the VIV response is analyzed with a range of m* (=1.4–3.4) relevant to cylindrical structures used in offshore engineering (such as subsea pipelines). The variations in the amplitude response, frequency response, and hydrodynamic coefficients with m* and reduced velocity are examined in detail. The present results suggest that a lighter pipeline is more susceptible to the onset of VIV. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is an autoimmune disorder characterized by chronic inflammation of the synovial joints and the dysfunction of regulatory T cells (Tregs) in the peripheral blood. Therefore, an optimal treatment strategy should aim to eliminate the inflammatory response in the joints and simultaneously restore the immune tolerance of Tregs in peripheral blood. Accordingly, we developed an efferocytosis‐mimicking nanovesicle that contains three functional factors for immunomodulating of efferocytosis, including "find me" and "eat me" signals for professional (macrophage) or non‐professional phagocytes (T lymphocyte), and "apoptotic metabolite" for metabolite digestion. We showed that efferocytosis‐mimicking nanovesicles targeted the inflamed joints and spleen of mice with collagen‐induced arthritis, further recruiting and selectively binding to macrophages and T lymphocytes to induce M2 macrophage polarization and Treg differentiation and T helper cell 17 (Th17) recession. Under systemic administration, the efferocytosis‐mimicking nanovesicles effectively maintained the pro‐inflammatory M1/anti‐inflammatory M2 macrophage balance in joints and the Treg/Th17 imbalance in peripheral blood to prevent RA progression. This study demonstrates the potential of efferocytosis‐mimicking nanovesicles for RA immunotherapy. [ABSTRACT FROM AUTHOR]

Two-dimensional (2-D) and three-dimensional (3-D) direct numerical simulations are conducted for flow past rectangular cylinders with various cross-sectional aspect ratios. The primary focuses are the interactions between the 2-D wake transitions in the spanwise vortex street (with distance downstream) and the 3-D wake transitions in the streamwise vortices, and the influence of both 2-D and 3-D wake transitions on the hydrodynamic forces on the cylinder. The 2-D wake transitions generally move upstream with increasing Reynolds number and decreasing aspect ratio. The corresponding reasons are explained. The 2-D wake transitions emerging close to the cylinder may directly alter the hydrodynamic forces on the cylinder, e.g. the Strouhal number, time-averaged drag coefficient and root-mean-square lift coefficient. By using specifically designed numerical cases to decompose the effects of the two 2-D transitions, it is found that the first 2-D transition from the primary to the two-layered vortex street results in reductions in the hydrodynamic forces, while the second 2-D transition to the secondary vortex street results in increases in the forces. The reduction/increase in the hydrodynamic forces becomes more significant when the transition location moves closer to the cylinder. The physical mechanisms for the influence on the hydrodynamic forces are elucidated. The upstream movement of the 2-D wake transitions also induces complex interactions between the 2-D and 3-D wake transitions (which also depends on the type of the 3-D mode). Correspondingly, the 3-D hydrodynamic forces may be governed by both 2-D and 3-D wake transitions (and their mutual influence). [ABSTRACT FROM AUTHOR]

Background: Osteonecrosis of the femoral head caused by glucocorticoids (GIONFH) is a significant issue resulting from prolonged or excessive clinical glucocorticoid use. Astaxanthin, an orange-red carotenoid present in marine organisms, has been the focus of this study to explore its impact and mechanism on osteoblast apoptosis induced by dexamethasone (Dex) and GIONFH. Methods: In this experiment, bioinformatic prediction, molecular docking and dynamics simulation, cytotoxicity assay, osteogenic differentiation, qRT-PCR analysis, terminal uridine nickend labeling (TUNEL) assay, determination of intracellular ROS, mitochondrial function assay, immunofluorescence, GIONFH rat model construction, micro-computed tomography (micro-CT) scans were performed. Results: Our research demonstrated that a low dose of astaxanthin was non-toxic to healthy osteoblasts and restored the osteogenic function of Dex-treated osteoblasts by reducing oxidative stress, mitochondrial dysfunction, and apoptosis. Furthermore, astaxanthin rescued the dysfunction in poor bone quality, bone metabolism and angiogenesis of GIONFH rats. The mechanism behind this involves astaxanthin counteracting Dex-induced osteogenic damage by activating the Nrf2 pathway. Conclusion: Astaxanthin shields osteoblasts from glucocorticoid-induced oxidative stress and mitochondrial dysfunction via Nrf2 pathway activation, making it a potential therapeutic agent for GIONFH treatment. [ABSTRACT FROM AUTHOR]

The utilization of extracellular vesicles (EV) in immunotherapy, aiming at suppressing peripheral immune cells responsible for inflammation, has demonstrated significant efficacy in treating various inflammatory diseases. However, the clinical application of EV has faced challenges due to their inadequate targeting ability. In addition, most of the circulating EV would be cleared by the liver, resulting in a short biological half-life after systemic administration. Inspired by the natural microvesicles (MV, as a subset of large size EV) are originated and shed from the plasma membrane, we developed the immunosuppressive MV-mimetic (MVM) from endotoxin tolerant dendritic cells (DC) by a straightforward and effective extrusion approach, in which DC surface proteins were inherited for providing the homing ability to the spleen, while αCD3 antibodies were conjugated to the MVM membranes for specific targeting of T cells. The engineered MVM carried a large number of bioactive cargos from the parental cells, which exhibited a remarkable ability to promote the induction of regulatory T cells (Treg) and polarization of anti-inflammatory M2 macrophages. Mechanistically, the elevated Treg level by MVM was mediated due to the upregulation of miR-155-3p. Furthermore, it was observed that systemic and local immunosuppression was induced by MVM in models of sepsis and rheumatoid arthritis through the improvement of Treg and M2 macrophages. These findings reveal a promising cell-free strategy for managing inflammatory responses to infections or tissue injury, thereby maintaining immune homeostasis. [ABSTRACT FROM AUTHOR]

Background: Rheumatoid arthritis (RA) is a prevalent inflammatory autoimmune disease characterised by persistent inflammation and joint damage with elevated levels of reactive oxygen species (ROS). Current treatment modalities for RA have significant limitations, including poor bioavailability, severe side effects, and inadequate targeting of inflamed joints. Herein, we synthesised cerium/manganese oxide nanoparticles (NPs) as efficient drug carriers with antioxidant and catalytic-like functions that can eliminate ROS to facilitate the polarization of macrophages phenotype from M1 to M2 and alleviate inflammation. Methotrexate (MTX), a first-line RA medication, was loaded into the NPs, which were further modified with bovine serum albumin (BSA) and integrated into dissolving hyaluronic acid-based microneedles (MNs) for transdermal delivery. Result: This innovative approach significantly enhanced drug delivery efficiency, reduced RA inflammation, and successfully modulated macrophage polarization toward an anti-inflammatory phenotype. Conclusion: This research not only presents a promising drug delivery strategy for RA but also contributes broadly to the field of immune disease treatment by offering an advanced approach for macrophage phenotypic reprogramming. [ABSTRACT FROM AUTHOR]

In recent years, the vitrified bond diamond grinding wheel has been applied widely in automotive, aerospace and machine tools of manufacturing industries. However, the main problems of low intensity and poor wettability between the vitrified bond and diamond abrasive limit its further application. In this study, BaO was added into the basic SiO2–B2O3–Al2O3–R2O vitrified bond system, and the impact of BaO on the wettability, thermal and mechanical behavior of vitrified bond and vitrified bond diamond composites was systematically discussed, respectively. The test indicated that when the vitrified bond containing BaO of 6 wt.% was sintered with diamond abrasive at 750 °C, a continuous barium feldspar phase transition layer between diamond abrasive and the bond was generated, which ameliorated the wet property of the bond–diamond abrasive. The contact angle varied from 59° on the blank sample to 35°, and the expansion coefficient changed from 6.24 × 10−6/K to 5.30 × 10−6/K. The Rockwell hardness and flexural strength of the vitrified bond diamond composites achieved the peaks of 117.5 MPa and 113.6 MPa, respectively, which increased by 20.2% and 16.5% compared with that of sample without the addition of BaO. [ABSTRACT FROM AUTHOR]

The preparation of aluminum-doped silica aerogel (ASA) typically utilizes alumina alkoxides or inorganic aluminum salts as precursors usually hindered by high cost or precursor instability. In this study, we prepared a high-temperature resistant ASA via the sol-gel and atmospheric pressure drying (APD) method, utilizing an inexpensive aluminum sol as the aluminum source, tetraethyl orthosilicate (TEOS) and basic silica sol as the composite silicon source. The effects of the Al/Si molar ratio and calcination temperature on the structure, morphology, and thermal stability of ASA were investigated. The results revealed that ASA-0.2 (with an Al/Si molar ratio of 0.2) exhibited a specific surface area of 616.3 m2/g at room temperature, whereas ASA-0 was 508.2 m2/g. After calcination at 1000 °C for 2 h, ASA-0.2 maintained a significantly higher specific surface area (290.0 m2/g) compared to ASA-0 (23.9 m2/g). Mechanism analysis indicated that adding aluminum sol not only improved the strength of the aerogel skeleton but also inhibited the phase transition of silica, effectively enhancing the high-temperature resistance of the aerogel. The utilization of inexpensive and stable aluminum sol as a precursor presents a promising approach for the industrial production of heat-resistant aerogels. Highlights: The preparation of aluminum-doped silica aerogels from aluminum sol as the aluminum source is discussed for the first time. The appropriate amount of aluminum sol can increase the specific surface area and optimize the pore structure of the aluminum-doped silica aerogels. The addition of aluminum sol significantly improves the high-temperature resistance of silica aerogels. [ABSTRACT FROM AUTHOR]

Glucocorticoid‐induced osteonecrosis of the femoral head (GIONFH) is the main complication secondary to long‐term or excessive use of glucocorticoids (GCs). Taxifolin (TAX) is a natural antioxidant with various pharmacological effects, such as antioxidative stress and antiapoptotic properties. The purpose of this study was to explore whether TAX could regulate oxidative stress and apoptosis in GIONFH by activating the nuclear factor erythroid 2‐related factor 2 (Nrf2) pathway. We conducted qRT‐PCR, Western blotting, TUNEL assays, flow cytometry, and other experiments in vitro. Microcomputed tomography analysis, hematoxylin–eosin staining, and immunohistochemical staining were performed to determine the therapeutic effect of TAX in vivo. TAX mitigated the overexpression of ROS and NOX gene expression induced by DEX, effectively reducing oxidative stress. Additionally, TAX could alleviate DEX‐induced osteoblast apoptosis, as evidenced by qRT‐PCR, Western blotting, and other experimental techniques. Our in vivo studies further demonstrated that TAX mitigates the progression of GIONFH in rats by combating oxidative stress and apoptosis. Mechanistic exploration revealed that TAX thwarts the progression of GIONFH through the activation of the Nrf2 pathway. Overall, our research herein reports that TAX‐mediated Nrf2 activation ameliorates oxidative stress and apoptosis for the treatment of GIONFH. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is a common degenerative joint disease characterized by progressive cartilage degradation and inflammation. In recent years, mesenchymal stem cells (MSCs) derived exosomes (MSCs-Exo) have attracted widespread attention for their potential role in modulating OA pathology. However, the unpredictable therapeutic effects of exosomes have been a significant barrier to their extensive clinical application. In this study, we investigated whether fucoidan-pretreated MSC-derived exosomes (F-MSCs-Exo) could better protect chondrocytes in osteoarthritic joints and elucidate its underlying mechanisms. In order to evaluate the role of F-MSCs-Exo in osteoarthritis, both in vitro and in vivo studies were conducted. MiRNA sequencing was employed to analyze MSCs-Exo and F-MSCs-Exo, enabling the identification of differentially expressed genes and the exploration of the underlying mechanisms behind the protective effects of F-MSCs-Exo in osteoarthritis. Compared to MSCs-Exo, F-MSCs-Exo demonstrated superior effectiveness in inhibiting inflammatory responses and extracellular matrix degradation in rat chondrocytes. Moreover, F-MSCs-Exo exhibited enhanced activation of autophagy in chondrocytes. MiRNA sequencing of both MSCs-Exo and F-MSCs-Exo revealed that miR-146b-5p emerged as a promising candidate mediator for the chondroprotective function of F-MSCs-Exo, with TRAF6 identified as its downstream target. In conclusion, our research results demonstrate that miR-146b-5p encapsulated in F-MSCs-Exo effectively inhibits TRAF6 activation, thereby suppressing inflammatory responses and extracellular matrix degradation, while promoting chondrocyte autophagy for the protection of osteoarthritic cartilage cells. Consequently, the development of a therapeutic approach combining fucoidan with MSC-derived exosomes provides a promising strategy for the clinical treatment of osteoarthritis. [ABSTRACT FROM AUTHOR]

Background: Steroid-induced avascular necrosis of the femoral head (SANFH) is characterized by osteoblast apoptosis, leading to a loss of bone structure and impaired hip joint function. It has been demonstrated that erythropoietin (EPO) performs a number of biological roles. Objective: We examined the effects of EPO on SANFH and its regulation of the STAT1-caspase 3 signaling pathway. Method: In vitro, osteoblasts were treated with dexamethasone (Dex) or EPO. We identified the cytotoxicity of EPO by CCK-8, the protein expression of P-STAT1, cleaved-caspase9, cleaved-caspase3, Bcl-2, BAX, and cytochrome c by Western blotting, and evaluated the apoptosis of osteoblasts by flow cytometry. In vivo, we analyzed the protective effect of EPO against SANFH by hematoxylin and eosin (H&E), Immunohistochemical staining, and Micro-computed tomography (CT). Results: In vitro, EPO had no apparent toxic effect on osteoblasts. In Dex-stimulated cells, EPO therapy lowered the protein expression of BAX, cytochrome c, p-STAT1, cleaved-caspase9, and cleaved-caspase3 while increasing the expression of Bcl-2. EPO can alleviate the apoptosis induced by Dex. In vivo, EPO can lower the percentage of empty bone lacunae in SANFH rats. Conclusion: The present study shows that EPO conferred beneficial effects in rats with SANFH by inhibiting STAT1-caspase 3 signaling, suggesting that EPO may be developed as a treatment for SANFH. [ABSTRACT FROM AUTHOR]

The low-valence cations Na+ and Sr2+ were selected as the co-dopants to increase the vacancies concentration in the Y2.982Ce0.018Al2Ga3O12 phosphor. The successful incorporation of Na+ and Sr2+ was confirmed by the X-Ray Diffraction (XRD) results. All the samples show 5d-4f green persistent luminescence of Ce3+ after 450 nm excitation. The decay curves demonstrate that the persistent luminescence is effectively enhanced with Na+ and Sr2+ doping. The thermoluminescence glow curves also show not only does the trap concentration increase, but also the distribution of trap depths is broadened. In addition, the air- and H2/Ar-annealing treatments were conducted on every as-made sample. The experimental results prove that the increased traps after the Na+/Sr2+ doping are mainly attributed to the oxygen vacancies, and the traps have a continuous and broad distribution of trap depths. We hope this work could give new inspiration for designing a high-performance persistent phosphor. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to detect the printing failures (such as warpage and collapse) in material extrusion (MEX) process effectively and timely to reduce the waste of printing time, energy and material. Design/methodology/approach: The approach is designed based on the frequently observed fact that printing failures are accompanied by abnormal material phenomena occurring close to the nozzle. To effectively and timely capture the phenomena near the nozzle, a camera is delicately installed on a typical MEX printer. Then, aided by the captured phenomena (images), a smart printing failure predictor is built based on the artificial neural network (ANN). Finally, based on the predictor, the printing failures, as well as their types, can be effectively detected from the images captured by the camera in real-time. Findings: Experiments show that printing failures can be detected timely with an accuracy of more than 98% on average. Comparisons in methodology demonstrate that this approach has advantages in real-time printing failure detection in MEX. Originality/value: A novel real-time approach for failure detection is proposed based on ANN. The following characteristics make the approach have a great potential to be implemented easily and widely: (1) the scheme designed to capture the phenomena near the nozzle is simple, low-cost, and effective; and (2) the predictor can be conveniently extended to detect more types of failures by using more abnormal material phenomena that are occurring close to the nozzle. [ABSTRACT FROM AUTHOR]

This paper presents a new flow control approach to suppress the vortex shedding in the wake of a circular cylinder through high-frequency oscillation. The circular cylinder is forced to oscillate in the streamwise direction at high-frequency and low amplitude, corresponding to a high Stokes number (β = 100–1000) and low Keulegan–Carpenter number (KC = 0.001–4). Two-dimensional (2-D) and three-dimensional (3-D) direct numerical simulations of an oscillating circular cylinder in steady current have been carried out in the parameter space of KC, Rec, and β. Our numerical results show that when the flow remains in the two-dimensional vortex shedding regime, the cylinder wake sequentially experiences transitions from the vortex shedding regime to the suppression of the vortex shedding regime and finally to the symmetry breaking regime, with increasing KC. Corresponding wake characteristics and variations of hydrodynamic forces over the three wake regimes are explored. Three quantities that represent shear-layer characteristics, including the length of separating shear layers, the circulation of shear layers and wake recirculation length, reach maxima at the onset of suppression. The physical mechanisms for the suppression of vortex shedding and occurrence of symmetry breaking are also explained. Once the flow becomes 3-D, vortex shedding from the cylinder cannot be suppressed, primarily because the outer shear layers induced by the steady approaching flow are enhanced in 3-D flows. The cylinder oscillation over the frequency range investigated in the present study delays wake transition to 3-D. The cylinder oscillation alters the 3-D vortical structure and its spanwise wavelength significantly. [ABSTRACT FROM AUTHOR]

We investigate the theoretical complexity of branch-and-bound (BB) and cutting plane (CP) algorithms for mixed-integer optimization. In particular, we study the relative efficiency of BB and CP, when both are based on the same family of disjunctions. We extend a result of Dash (International Conference on Integer Programming and Combinatorial Optimization (IPCO), pp. 145–160, 2002) to the nonlinear setting which shows that for convex 0/1 problems, CP does at least as well as BB, with variable disjunctions. We sharpen this by giving instances of the stable set problem where we can provably establish that CP does exponentially better than BB. We further show that if one moves away from 0/1 sets, this advantage of CP over BB disappears; there are examples where BB finishes in O(1) time, but CP takes infinitely long to prove optimality, and exponentially long to get to arbitrarily close to the optimal value (for variable disjunctions). We next show that if the dimension is considered a fixed constant, then the situation reverses and BB does at least as well as CP (up to a polynomial blow up factor), for quite general families of disjunctions. This is also complemented by examples where this gap is exponential (in the size of the input data). [ABSTRACT FROM AUTHOR]

We define a new cutting plane closure for pure integer programs called the two-halfspace closure. It is a natural generalization of the well-known Chvátal-Gomory closure. We prove that the two-halfspace closure is polyhedral. We also study the corresponding two-halfspace rank of any valid inequality and show that it is at most the split rank of the inequality. Moreover, while the split rank can be strictly larger than the two-halfspace rank, the split rank is at most twice the two-halfspace rank. A key step of our analysis shows that the split closure of a rational polyhedron can be obtained by considering the split closures of all k-dimensional (rational) projections of the polyhedron, for any fixed k ≥ 2 . This result may be of independent interest. [ABSTRACT FROM AUTHOR]

The turbulent kinetic energy and energy dissipation rate in the wake of a circular cylinder are examined at a Reynolds number of 1000. The turbulence characteristics are quantified using direct numerical simulation, which provides a comprehensive dataset that is almost impossible to acquire from physical experiments. The energy dissipation rate is decomposed into the components due to the mean flow, the coherent primary vortices and the remainder. It is found that the remainder component, which develops only in a three-dimensional turbulent wake and resides mainly in the regions of vortices, accounts for 95 % and 97 % of the total dissipation rate for 10 and 20 cylinder diameters downstream of the cylinder, respectively (while the remainder accounts for 62 % and 83 % of the total turbulent kinetic energy). Based on the remainder component, the validity of local isotropy, local axisymmetry, local homogeneity and homogeneity in the y–z plane for the turbulent dissipation in the wake is examined. The analysis reveals that the turbulent dissipation is largely locally homogeneous, but not locally isotropic or axisymmetric, even after the annihilation of the primary vortex street. In addition, the performances of the four corresponding surrogates to the true dissipation rate are evaluated. Owing to the general validity of local homogeneity, the surrogates of local homogeneity and homogeneity in the y–z plane perform well. Although local axisymmetry does not hold, the corresponding surrogate performs well, because errors from different terms largely cancel out. However, the surrogate of local isotropy generally underestimates the true dissipation rate. [ABSTRACT FROM AUTHOR]

The effects of yaw angle on wake characteristics of a stationary square cylinder were investigated in terms of the hydrodynamic forces, the vortex shedding frequency, and the vortical structures using direct numerical simulations (DNS) at a Reynolds number of 1000. In total, four yaw angles, namely, α = 0°, 15°, 30°, and 45°, were considered. The three-dimensional (3D) Navier–Stokes equations were solved directly using the finite volume method in OpenFOAM. It was found that the first-order statistics of the drag coefficient and the Strouhal number satisfied the independence principle (IP) closely. However, the second-order statistics of the drag and lift coefficients deviated apparently from the IP for α ≥ 25°. The iso-surfaces of the spanwise vorticity gradually disorganized and the magnitudes of the spanwise vorticity contour decreased as the yaw angle α was increased from 0° to 45°. By contrast, the streamwise vorticity iso-surfaces were found to become more organized and the magnitudes of the spanwise velocity contour became larger as a result of the increase in yaw angle, indicating the impairment of the quasi-two-dimensionality and the enhancement of the three-dimensionality of the wake flow. Extensive comparisons were also made with previous DNS results for a yawed circular cylinder, and both similarities and differences between these two kinds of cylinder wakes are discussed. [ABSTRACT FROM AUTHOR]

Positioning technology is an important component of environmental perception and the basis of decision-making and motion control for intelligent vehicles. Current independent positioning methods inevitably have defects and poor environmental adaptability. To improve positioning accuracy and stability using low-cost sensors, a multi-sensor fusion positioning strategy for intelligent vehicles using global pose graph optimization is proposed in this paper. This strategy complements the advantages of multiple sensors to obtain global optimal positioning results, and it can cope with a variety of challenging working conditions. Considering the fast response of the inertial measurement unit (IMU) and the advantages of a camera without drift, this strategy realizes the tightly coupled fusion of vision and the IMU to obtain the optimal pose of visual-inertial odometry (VIO) by nonlinear optimization. Moreover, this strategy refines the modeling of the IMU, and proposes a keyframe selection strategy to deal with driving in a straight line without obvious feature changes, turning, and other driving conditions. Taking into account the versatility of the global positioning system (GPS) and the low cost of the network real-time kinematic (NRTK) positioning, the output of VIO and GPS/NRTK is adaptively fused through global pose graph optimization to maintain global consistency. Finally, the multi-sensor fusion positioning strategy is verified using the KITTI dataset on the ROS simulation platform. The results show that the multi-sensor fusion positioning strategy for intelligent vehicles has better accuracy and environmental adaptability at a lower cost than state-of-the-art strategies. [ABSTRACT FROM AUTHOR]

Long non-coding RNAs (lncRNAs) in immune cells play critical roles in tumor cell–immune cell interactions. This study aimed to characterize the landscape of tumor-infiltrating immune-related lncRNAs (Ti-lncRNAs) and reveal their correlations with prognoses and immunotherapy response in head and neck squamous cell carcinoma (HNSCC). We developed a computational model to identify Ti-lncRNAs in HNSCC and analyzed their associations with clinicopathological features, molecular alterations, and immunotherapy response. A signature of nine Ti-lncRNAs demonstrated an independent prognostic factor for both overall survival and disease-free survival among the cohorts from Fudan University Shanghai Cancer Center, The Cancer Genome Atlas, GSE41613, and GSE42743. The Ti-lncRNA signature scores in immune cells showed significant associations with TP53 mutation, CDKN2A mutation, and hypoxia. Inferior signature scores were enriched in patients with high levels of PDCD1 and CTLA4 and high expanded immune gene signature (IGS) scores, who displayed good response to PD-1 blockade in HNSCC. Consistently, superior clinical response emerged in melanoma patients with low signature scores undergoing anti-PD-1 therapy. Moreover, the Ti-lncRNA signature was a prognostic factor independent of PDCD1, CTLA4, and the expanded IGS score. In conclusion, tumor-infiltrating immune profiling identified a prognostic Ti-lncRNA signature indicative of clinical response to PD-1 blockade in HNSCC. [ABSTRACT FROM AUTHOR]

In recent years, a large number of studies have reported that neuroinflammation aggravates the occurrence of secondary injury after spinal cord injury. Gramine (GM), a natural indole alkaloid, possesses various pharmacological properties; however, the anti‐inflammation property remains unclear. In our study, Gramine was investigated in vitro and in vivo to explore the neuroprotection effects. In vitro experiment, our results suggest that Gramine treatment can inhibit release of pro‐inflammatory mediators. Moreover, Gramine prevented apoptosis of PC12 cells which was caused by activated HAPI microglia, and the inflammatory secretion ability of microglia was inhibited by Gramine through NF‐κB pathway. The in vivo experiment is that 80 mg/kg Gramine was injected orthotopically to rats after spinal cord injury (SCI). Behavioural and histological analyses demonstrated that Gramine treatment may alleviate microglia activation and then boost recovery of motor function after SCI. Overall, our research has demonstrated that Gramine exerts suppressed microglia activation and promotes motor functional recovery after SCI through NF‐κB pathway, which may put forward the prospect of clinical treatment of inflammation‐related central nervous diseases. [ABSTRACT FROM AUTHOR]

Three-dimensional (3-D) wake transition for flow past a diamond cylinder is investigated numerically. Detailed 3-D direct numerical simulations (DNS) show that the wake is represented by mode A with global vortex dislocations for Reynolds numbers Re = 121–150, followed by a mode swapping between modes A and B for Re = 160–210 and increasingly disordered mode B for Re ≥ 220. In the mode swapping regime, different characteristics of the dislocation and non-dislocation periods are revealed by decomposing flow properties (e.g. the root-mean-square lift coefficient) into the values corresponding to the dislocation and non-dislocation periods. Such decomposition helps to explain some major differences observed for the cases of a diamond and a circular cylinder. In addition to DNS, Floquet stability analyses are conducted to identify the 3-D wake instability modes of a diamond cylinder up to Re = 300. Phase-averaged base flow is used to eliminate the quantitative uncertainties induced by the aperiodic secondary vortex street of the base flow. Interestingly, a subharmonic instability mode is identified at Re ≥ 285, whereas mode B is absent. The origin of the subharmonic mode is explained. The disagreement between the DNS and the Floquet analysis regarding the existence of mode B and the subharmonic mode is also explained. It is found that the natural 3-D flow involves complex interactions between the streamwise and spanwise vortices, as well as between the 3-D wake transition and the two-dimensional base-flow transition, which excite mode B and suppress the subharmonic mode. [ABSTRACT FROM AUTHOR]

Background: A number of long non-coding RNAs (lncRNAs) have been found to be involved in tumor progression and associated with disease prognoses in various types of cancer. Our study identified a novel three-lncRNA signature to predict survival of head and neck squamous cell caner (HNSCC) patients. Methods: We utilized The Cancer Genome Atlas (TCGA) cohort to screen out overall survival (OS)-associated lncRNAs in HNSCC and further developed a model to identify a lncRNA signature for evaluating disease status and prognosis. The lncRNA signature was then validated in HNSCC patients from our Fudan University Shanghai Cancer Center (FUSCC) cohort. Results: LINC02434, AL139327.2, and AC126175.1 were identified by multivariable Cox regression analyses of independent risk factors for deceased status. We built a risk score model based on the three-lncRNA signature using coefficient of multivariable Cox regression and expression value of the three lncRNAs. The high-risk signature score was significantly associated with decreased OS in both the TCGA cohort and the FUSCC cohort. The high-risk group had worse overall survival than the low-risk group in TCGA cohort. To further validate the robustness of three-lncRNA signature risk score model developed in the TCGA dataset, the performance of risk score also evaluated in our institute FUSCC cohort. Additionally, the signature score showed a positive correlation with aggressive outcomes of HNSCC, such as III/IV stage, TP53 mutation, and PI3KCA mutation. The gene set enrichment analysis indicates that the risk score is associated with cancer metastasis-related pathways. Several cancer-related pathways, such as epithelial mesenchymal transition, TNFα signaling via NF-κB, MYC targets, and angiogenesis. Conclusions: The three-lncRNA signature could provide a novel prediction insight into the prognosis of HNSCC patients. The three-lncRNA signature was identified as a predictor of poor prognoses in HNSCC, which may serve as a potential therapeutic target. [ABSTRACT FROM AUTHOR]

Background: Differentiated thyroid cancer (DTC) is the most common type of thyroid cancer. Many of them can relapse to dedifferentiated thyroid cancer (DDTC) and exhibit different gene expression profiles. The underlying mechanism of dedifferentiation and the involved genes or pathways remained to be investigated. Methods: A discovery cohort obtained from patients who received surgical resection in the Fudan University Shanghai Cancer Center (FUSCC) and two validation cohorts derived from Gene Expression Omnibus (GEO) database were used to screen out differentially expressed genes in the dedifferentiation process. Weighted gene co-expression network analysis (WGCNA) was constructed to identify modules highly related to differentiation. Gene Set Enrichment Analysis (GSEA) was used to identify pathways related to differentiation, and all differentially expressed genes were grouped by function based on the GSEA and literature reviewing data. Least absolute shrinkage and selection operator (LASSO) regression analysis was used to control the number of variables in each group. Next, we used logistic regression to build a gene signature in each group to indicate differentiation status, and we computed receiver operating characteristic (ROC) curve to evaluate the indicative performance of each signature. Results: A total of 307 upregulated and 313 downregulated genes in poorly differentiated thyroid cancer (PDTC) compared with papillary thyroid cancer (PTC) and normal thyroid (NT) were screened out in FUSCC cohort and validated in two GEO cohorts. WGCNA of 620 differential genes yielded the seven core genes with the highest correlation with thyroid differentiation score (TDS). Furthermore, 395 genes significantly correlated with TDS in univariate logistic regression analysis were divided into 11 groups. The areas under the ROC curve (AUCs) of the gene signature of group transcription and epigenetic modification, signal and substance transport, extracellular matrix (ECM), and metabolism in the training set [The Cancer Genome Atlas (TCGA) cohort] and validation set (combined GEO cohort) were both >0.75. The gene signature based on group transcription and epigenetic modification, cilia formation and movement, and proliferation can reflect the patient's disease recurrence state. Conclusion: The dedifferentiation of DTC is affected by a variety of mechanisms including many genes. The gene signature of group transcription and epigenetic modification, signal and substance transport, ECM, and metabolism can be used as biomarkers for DDTC. [ABSTRACT FROM AUTHOR]

The benchmarking case of flow past a circular cylinder at the Reynolds number (Re) of 3900 is computed with two open-source codes, OpenFOAM and Nektar++, which are based on the conventional finite volume method (FVM) and the high-order spectral/hp element method, respectively. By using the Nektar++ model, mesh convergence for the case Re = 3900 is demonstrated (perhaps for the first time) through a systematic mesh dependence study, which includes separate examinations of the spanwise domain length (Lz/D), spanwise resolution, and the resolution in the plane perpendicular to the spanwise direction. The computational efficiencies for the Nektar++ and OpenFOAM approaches are then compared. This benchmarking study adds value to the broad Nektar++ and OpenFOAM communities and to the numerical modeling of bluff-body flows in general. Based on the Nektar++ approach, the computations are then generalized to a range of Re = 400–3900. It is found that Lz/D = 3 is adequate for Re = 2500–3900, while an increased Lz/D = 6 is recommended for Re = 400–2000. Based on the present high-fidelity numerical data, the physical mechanisms for the variations in the wake recirculation length and the hydrodynamic forces and pressure on the cylinder with Re are explored. In particular, the physics behind the inverse correlation between the root mean square lift coefficient (CL′) and the wake recirculation length, which includes a significant decrease in CL′ over Re = 270–1500, is highlighted. [ABSTRACT FROM AUTHOR]

Background and Objectives: Targeting cancer-associated fibroblast (CAF) is being explored as an approach to improve cancer therapies. The roles of CAF remain unclarified in malignant transformation of papillary thyroid cancer (PTC) into dedifferentiated thyroid cancer (DDTC). This study aimed to investigate correlations of CAF with dedifferentiation and clinicopathological characteristics of thyroid cancer. Materials and Methods: We applied three different mRNA-based CAF gene signatures to quantify CAF in our cohort, the Gene Expression Omnibus (GEO) cohort and The Cancer Genome Atlas (TCGA) cohort, and analyzed expression of α-SMA by immunohistochemistry in thyroid cancer. The CAF score was analyzed for its associations with clinicopathological characteristics, genetic mutations, tumor-associated signaling pathways and immune landscape. Results: The CAF score increased significantly in DDTCs compared with normal thyroid tissues and PTCs, and the α-SMA-positive CAFs were found enriched in DDTCs. The high CAF score showed a significant correlation with the anaplastic phenotype in DDTC and low thyroid differentiation score in PTC. Patients with a high CAF score remarkably increased the risk of aggressive outcomes in both DDTC and PTC. Furthermore, the CAF score was positively correlated with genetic mutations, oncogenic signaling pathways, the immune score and increased expression of tumor microenvironment (TME) target markers. Conclusion: Our findings suggest CAFs positively correlate with dedifferentiation and aggressive outcomes of thyroid cancer, and targeting CAFs as a therapeutic approach may benefit DDTC patients. [ABSTRACT FROM AUTHOR]

Background: Recently, radioiodine refractory differentiated thyroid cancer (RR-DTC) has received increasing attention due to its poor prognosis. The roles of clinical, pathological, and molecular features in the development of RR-DTC remain controversial and require additional investigation. This study aimed to evaluate the association between these risk factors and the occurrence of RR-DTC. Methods: We performed a systematic search for relevant literature following the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) in PubMed, EMBASE, Medline, SCOPUS, and Web of Science up to the July 15, 2020. Observational studies that investigated the risk factors for RR-DTC were included. Fixed- or random-effects models were used to calculate pooled odds ratios (ORs) or mean differences (MD) with corresponding 95% confidence intervals. Results: We included 13 eligible studies incorporating 1,431 cases, of which 603 were patients with RR-DTC. The pooled analysis indicated that four parameters significantly increased the risk of RR-DTC: extrathyroidal extension (ETE) (OR: 2.28, 95% CI: 1.43–3.64, I 2 = 14%), BRAF V 600 E mutation (OR: 3.60, 95% CI: 1.74–7.46, I 2 = 69%), TERT promoter mutation (OR: 9.84, 95% CI: 3.60–26.89, I 2 = 61%) and high-risk histological subtype (OR: 1.94, 95% CI: 1.15–3.27, I 2 = 15%), including tall cell variant papillary thyroid carcinoma (PTC), sclerosing diffuse PTC, hobnail variant PTC, follicular thyroid carcinoma (FTC) (including Hürthle cell), and poorly differentiated thyroid carcinoma (PDTC). However, there was no statistical significance regarding sex, age, tumor size, multifocality, or lateral lymph node metastasis. Subgroup and sensitivity analyses were conducted to further confirm the robustness of the results. Conclusions: Histological subtype, ETE, BRAF V 600 E mutation, and TERT promoter mutation could be considered clinicopathological factors and biomarkers. They could assist in risk stratification, prognostic prediction, and individual therapy options for RR-DTC. [ABSTRACT FROM AUTHOR]

In order to develop high-performance diamond wheels, the vitrified bond with different contents of Li2O addition and corresponding diamond composites were prepared. The experimental results show that the addition of a small content of Li2O leads the formation of the mullite phase in vitrified bond. When the Li2O content is 3wt%, the mullite content in the vitrified bond reaches the maximum. Whereas, the vitrified bond turns into a pure glass phase when the Li2O content further increases to 5wt%. The softening temperature of vitrified bond, wetting angle between the vitrified bond and the diamond film decrease with the increasing of the Li2O content. The softening point of the vitrified bond with 5wt% Li2O is 537 °C and the contact angle is 32°, which are 44 °C and 44° lower than those of the sample without Li2O. The CTE (coefficient of thermal expansion), the flexural strength and hardness of the diamond composite sample first increase and then decrease with the increasing of the Li2O content. When the Li2O addition is 3wt%, the flexural strength and hardness of the composites reaches the maximum values of 93 MPa and 98 HRB, respectively, which are 43.1% and 12.6% higher than those of the sample without Li2O. [ABSTRACT FROM AUTHOR]

Flow (of a Newtonian and incompressible fluid) separation around a square cylinder for Reynolds numbers (Re) in the range of 10–400 is investigated through direct numerical simulations. In contrast to the general belief that for a square cylinder, the flow would always separate at the leading and/or trailing edges of the cylinder, this study shows that the flow (both time-averaged and instantaneous) may not separate at the sharp corners for a certain range of moderate Re values. Instead, separation emerges at approximately a quarter of the cylinder length downstream of the leading edge at critical Re values of 100.36 and 96 for the time-averaged and instantaneous flows, respectively. With the increase in Re, the time-averaged separation location gradually moves toward the leading edge, while its instantaneous variation range reduces. The evolution of the separation pattern with Re is categorized with a fine Re resolution of 1. A critical point is identified at Re = 156 (for the time-averaged flow), where a saddle point emerges away from the upper/lower surface of the cylinder to give rise to wake flow entrainment to the upper/lower side of the cylinder. The rate of the entrained flow is governed by the location of the saddle point. The flow three-dimensionality occurring at Re > 165.7 affects the location of the saddle point but has almost no influence on the location of the separation point. The corresponding physical mechanism is explained. [ABSTRACT FROM AUTHOR]

Instantaneous and time-averaged flow separation locations for the canonical case of flow past a circular cylinder are investigated through direct numerical simulations. It is found that the instantaneous movement of the upper/lower separation point on the cylinder surface is governed by a dynamic balance between the upper/lower separating shear layer and a shear layer generated at the back of the cylinder due to wake recirculation. It is also found that flow three-dimensionality contributes to an upstream movement of the time-averaged separation point through the effect of the separating shear layer. For the three-dimensional flow, the disordered mode B flow structures developed in the separating shear layer (which is directly responsible for the flow three-dimensionality) would result in turbulent energy dissipation and, therefore, the separating shear layer is less rolled-up in the cross-flow direction, which weakens the effect of the separating shear layer in pushing the separation point downstream. The time-averaged separation angle vs the Reynolds number ( θ s ¯ − R e) relationship is not monotonic over the three-dimensional wake transition regimes of Re = 190–270 since there is a transition sequence of different wake flow patterns with different levels of flow three-dimensionality. For Re ≥ 270, on the physical basis that the increasingly disordered mode B flow becomes the sole wake flow pattern, an empirical formula is proposed for the θ s ¯ − R e relationship, i.e., θ s ¯ = 78.8 + 505 R e − 1 / 2 (270 ≤ Re ≲ 105). [ABSTRACT FROM AUTHOR]

The evolution of Mode C wake characteristics with the Reynolds number (Re) for Re up to 400 is investigated numerically. The Mode C wake instability is generated by placing a small wire in the near wake of a main circular cylinder. This setup ensures that the wake is unstable to Mode C only (without potential mode interactions), as demonstrated by Floquet stability analysis. Based on three-dimensional direct numerical simulations, three evolution regimes are identified for the fully developed Mode C flow. In the uniform periodic regime (Re = 166.4–210), the Mode C structure is uniformly distributed along the spanwise direction. The flow structure is 2T-periodic (T being the vortex shedding period) but retains a spatiotemporal symmetry every 1T. In the nonuniform periodic regime (Re = 220–230), the slightly nonuniform Mode C structure remains 2T-periodic at Re = 220 but undergoes a period quadrupling to 4T-periodic at Re = 230 before transitioning to chaos. In the chaotic regime (Re ≥ 240), the flow loses periodicity and becomes increasingly chaotic with increasing Re. The progressive wake transition to chaos is found to originate from the instability in the braid shear layer region through the uneven growth in strength and the consequent nonuniformity of the Mode C streamwise vortices. The wake transitions to chaos through the routes of Mode C and Mode B (for an isolated circular/square cylinder) are compared. [ABSTRACT FROM AUTHOR]

In recent years, circular RNAs (circRNAs) have been identified to be essential regulators of various human cancers. However, knowledge of the functions of circRNAs in prostate cancer remains very limited. The correlation between circABCC4 and human cancer is largely unknown. This study aims to investigate the biological functions of circABCC4 in prostate cancer progression and illustrate the underlying mechanism. We found that circABCC4 was remarkably up‐regulated in prostate cancer tissues and cell lines and promoted FOXP4 expression by sponging miR‐1182 in prostate cancer cells. CircABCC4 knockdown markedly suppressed prostate cancer cell proliferation, cell‐cycle progression, migration and invasion in vitro. Furthermore, silencing of the circRNA also delayed tumor growth in vivo. Taken together, our findings indicated that circABCC4 facilitates the malignant behaviour of prostate cancer by promoting FOXP4 expression through sponging of miR‐1182. The circABCC4–miR‐1182‐FOXP4 regulatory loop may be a promising therapeutic target for prostate cancer intervention. [ABSTRACT FROM AUTHOR]

Al2O3 hollow microspheres without noticeable aggregation have been prepared via a facile templating route with urea-mediated precipitation. The precipitation process is different from the surface-adsorption method which is confined to the adsorption capacity of the template surface. TEM and SEM images indicate that most of these Al2O3 hollow microspheres with shell thickness of tens of nanometers and diameters in a narrow range of 100–200 nm consist of a shell of closely packed nanoparticles. The optimal amount of H2O and EtOH are 40 and 120 mL, respectively. The specific surface area, average pore size and pore volume of the Al2O3 hollow microspheres (calcinated at 600 °C) are 328.52 m2/g, 17.496 nm and 1.985 cm3/g, respectively. As the calcination temperature increases from 600 to 1 100 °C, the phase composition changes from γ-Al2O3 to θ-Al2O3 and α-Al2O3, and the surface morphology appears to change from a relatively rough surface formed by nanoparticles to a smooth surface formed by lamellar, which lead to the closure of pore channels and the reduction of specific surface. [ABSTRACT FROM AUTHOR]

Instabilities and flow characteristics in the far wake of a circular cylinder are examined through direct numerical simulations. The transitions to the two-layered and secondary vortex streets are quantified by a new method based on the time-averaged transverse velocity field. Two processes for the transition to the secondary vortex street are observed: (i) the merging of two same-sign vortices over a range of low Reynolds numbers (Re) between 200 and 300, and (ii) the pairing of two opposite-sign vortices, followed by the merging of the paired vortices into subsequent vortices, over a range of Re between 400 and 1000. Single vortices may be generated between the merging cycles due to mismatch of the vortices. The irregular merging process results in flow irregularity and an additional frequency signal ƒ2 (in addition to the primary vortex shedding frequency ƒ1) in the two-layered and secondary vortex streets. In particular, a gradual energy transfer from ƒ1 to ƒ2 with distance downstream is observed in the two-layered vortex street prior to the merging. The frequency spectra of ƒ2 are broad-band for Re = 200 –300 but become increasingly sharp-peaked with increasing Re because the vortex merging process becomes increasingly regular. The ratio of the sharp-peaked frequencies ƒ2 and ƒ1 is equal to the ratio of the numbers of vortices observed after and before the merging. The general conclusions drawn from a circular cylinder are expected to be applicable to other bluff bodies. [ABSTRACT FROM AUTHOR]

This study attempts to investigate the relationship among electricity consumption, economic growth, and employment in China. Distinct from most of the previous studies, our empirical research identifies a long-run equilibrium cointegration relationship among the three covariates during the period of 1971–2009 with the recently developed autoregressive distributed lag (ARDL) bounds testing approach. The parameters are estimated through a long-run static solution of the estimated ARDL model and short-run dynamic solutions of the error correction model. The estimated models successfully pass diagnostic tests and both the long-run and short-run elasticities are found to be statistically significant. The study also indicates the existence of short-run and long-run causalities from electricity consumption and employment to economic growth. Results of this study show that electricity serves as an important driver of economic growth. Based on these results, several policy prescriptions on energy use and economic development are suggested for China. [ABSTRACT FROM AUTHOR]

Objects: To evaluate prognostic factors and treatment outcomes of primary squamous cell carcinoma in thyroid (PSCCTh) over the past decades using a large national database. Methods: All patients diagnosed with PSCCTh between 1973 and 2015 were identified with the Surveillance, Epidemiology, and End Results Program (SEER) 18-registry database. Relevant clinical data were collected, and prognostic factors of overall survival (OS) and disease-specific survival (DSS) were analyzed. Results: This cohort study included 242 patients, accounting for 0.12% of all primary thyroid carcinomas from 1973 to 2015 nationwide. Of the patients with PSCCTh, 75% were older than 60 years at diagnosis. Patient age older than 60 years (HR 2.242, 95% CI 1.367–3.676, P = 0.001) and a tumor size larger than or equal to 50 mm (HR 1.479, 95% CI 1.011–2.165, P = 0.044) were independent negative prognostic factors. The univariate analysis suggested that the morphological subtype (OS, P = 0.033; DSS, P = 0.048), clinical treatment modality (OS, P < 0.0001; DSS, P < 0.0001), and T stage (OS, P = 0.004; DSS, P = 0.001) were important predictive factors for OS and DSS. In contrast, gender, race, year of diagnosis, geographic location, N stage, and M stage were not prognostic factors. Conclusions: PSCCTh is a rare malignancy with an aggressive nature and poor prognosis. Survival is predicted by the treatment modality, patient age, T stage, tumor size, and morphological subtypes. This study showed that early diagnosis and complete surgical resection plus adjuvant radiation therapy were associated with a better outcome. [ABSTRACT FROM AUTHOR]

This paper studies the friendship paradox for weighted and directed networks, from a probabilistic perspective. We consolidate and extend recent results of Cao and Ross and Kramer, Cutler and Radcliffe, to weighted networks. Friendship paradox results for directed networks are given; connections to detailed balance are considered. [ABSTRACT FROM AUTHOR]

Xonotlite fibers (XFs) reinforced silica aerogel composites were prepared by a sol-gel method under ambient pressure drying. XFs were synthesized through a dynamic hydrothermal route and had a noodle-like structure with length of 5-10 μm and average diameter of 150-200 nm. The microstructure analysis showed that XFs were inlaid in silica aerogel matrix by physical combination which contributed to restrict the volume shrinkage of alcogels and maintain the integrality aerogels during drying process. The physical, naonporous and thermal properties of the as prepared aerogel composites were investigated and discussed in detail. The new aerogel composites possessed porous nanostructure, which exhibited typical properties of 0.126 g/cm3 density, 4.132 cm3/g pore volume, and thermal conductivity of 0.0285 W/(m K). The results indicated that the introduced XFs didn’t significantly alter the porosity, hydrophobicity or thermal conductivity of aerogel matrix. It was also found that the aerogel composites had much more outstanding porosity than that of pure aerogel upon calcinations at 800 °C. This study fabricated XFs-silica aerogel composites and explored a new way for silica aerogels to endure and remain monolithic under ambient pressure drying. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) and three-dimensional (3D) hydrodynamic characteristics of flow past a square cylinder are investigated using direct numerical simulations. The variations of the hydrodynamic forces and wake flow characteristics with the Reynolds number (Re) are examined for Re = 10–400 with a high resolution in Re. Distinct features in the variation trends of the hydrodynamic forces with Re are examined and explained. In addition, for the 3D flows up to Re = 400, three critical conditions are observed at Re of approximately 165.7, 210, and 330. At the onset of the secondary wake instability of Re = 165.7, a sudden increase or decrease in the 3D flow property with respect to its 2D counterpart is observed, which is due to the sudden increase in the flow three-dimensionality at the mode A instability that is subcritical in nature. The second critical condition is because for Re > 210, the mode B flow structure becomes increasingly disordered and the wake flow becomes increasingly turbulent such that the 3D flow property is increasingly deviated from its 2D counterpart. The third critical condition at Re ∼ 330 is related to the disappearance and reappearance of the recirculation regions on the upper and lower sides of the cylinder. While the first two critical conditions are also observed for flow past a circular cylinder, the third one is not since the geometry of a circular cylinder does not give rise to recirculation regions on the upper and lower sides of the cylinder. [ABSTRACT FROM AUTHOR]

Sr2MgSi2O7:Eu2+,Dy3+ long afterglow materials were prepared by a high-temperature solid-state reaction method with different cooling rates. The cooling rate had a slight effect on X-ray diffraction patterns and photoluminescence performance, but significantly modified the grain boundaries and long afterglow properties of the Sr2MgSi2O7:Eu2+,Dy3+ materials. When the cooling rate was 1°C/min, grains remained intact with clear grain boundaries. As the cooling rate increased from 1°C/min to 5°C/min, some grain boundaries became indistinguishable. The afterglow properties were optimized, presenting best performance at the cooling rate of 3°C/min. The trap state was investigated and illustrated through thermoluminescence curves. The depths of the traps of all the samples were unchanged, whereas densities changed to a large extent, leading to different afterglow properties. The retrapping process is discussed based on the afterglow curves. [ABSTRACT FROM AUTHOR]