The vibro-acoustic responses of coupled pump-jet-submarine systems excited by fluid excitations on the wall of the duct are numerically investigated. The unsteady excitations are calculated by ...computational fluid dynamics and the vibration responses for different excitations on the inner and outer walls are contrastively analyzed through establishing a finite element model of the coupled system. Meanwhile, the effect of fluid–structure interaction and the excitation loading methods for the inner flow of duct are considered. The sound radiation characteristics for different excitation sources are predicted through using a boundary element model. The results show that the excitation force spectra of the inner wall have a remarkable discrete peak at blade passing frequency and its multiple, while the excitation force spectra of the outer wall show a broadband characteristic and discrete components appear at blade passing frequency. The modes of hull both dominate the vibro-acoustic responses of the coupled system for different excitation sources of the duct. The transmitted energy for inner excitation forces is significantly greater than that of outer excitation forces, but the sound radiation efficiency is relatively close. The excitations of the duct can transfer to the thrust bearing through stators as well as the hull and cause a coupled vibration between the duct–stator–hull and the shafting system. Besides, the method for applying distributed forces on the inner wall is more reliable.
Frost heave pressure plays a pivotal role in driving the occurrence and expansion of rock cracks. Thus, understanding the distribution and evolution of frost heave pressure on rock crack surfaces is ...integral to elucidate the mechanism of rock mass damage caused by freeze-thaw. In this study, a unique frost heave pressure monitoring experiment was performed, employing a membrane pressure sensor to provide real-time monitoring of frost heave pressure distribution across an entire rock crack surface. Simultaneously, temperature changes within the crack during freeze-thaw were monitored. Various factors including freezing temperature, crack water content, and lithology, were analyzed for their influence on the frost heave pressure distribution on the crack surface. Findings indicate that the frost heave pressure evolution during freeze–thaw can be divided into five stages: incubation, eruption, fall, equilibrium, and dissipation. The frost heave pressure is not uniformly distributed across the rock crack surfaces, with 0 MPa pressure on the upper part of the crack. The distribution pattern of frost heave pressure on the crack surface features smaller edges surrounding a larger middle area. No obvious correlation is observed between the maximum frost heave pressure and the freezing temperature. However, as the freezing temperature decreases, the maximum pressure-bearing area on the rock crack surface gradually increases. Additionally, as the water content within the crack decreases, there is a noticeable decrease in the distribution of frost heave pressure on the rock crack surface. Regarding frost heave pressure monitoring tests under four different lithological conditions, crack expansion was observed in fine sandstone, granite, and limestone specimens, but not in coarse sandstone specimens. The findings from this research enrich our understanding of the incubation mechanism of rock mass freeze–thaw disasters in cold regions, and serve as a reference for calculations and numerical simulations of rock crack frost heave pressure in these areas.
•The evolution of frost heave pressure distribution on a rock crack surface was determined.•The frost heave pressure on the upper part of the crack was found to be 0 MPa.•Frost heave pressure was unevenly distributed across the crack surface.•A lower freezing temperature resulted in a larger pressure-bearing area on the crack surface.
In the field of bone defect repair, 3D printed scaffolds have the characteristics of personalized customization and accurate internal structure. However, how to construct a well-structured vascular ...network quickly and effectively inside the scaffold is essential for bone repair after transplantation. Herein, inspired by the unique biological structure of “lotus seedpod”, hydrogel microspheres encapsulating deferoxamine (DFO) liposomes were prepared through microfluidic technology as “lotus seeds”, and skillfully combined with a three-dimensional (3D) printed bioceramic scaffold with biomimetic “lotus” biological structure which can internally grow blood vessels. In this composite scaffold system, DFO was effectively released by 36% in the first 6 h, which was conducive to promote the growth of blood vessels inside the scaffold quickly. In the following 7 days, the release rate of DFO reached 69%, which was fundamental in the formation of blood vessels inside the scaffold as well as osteogenic differentiation of bone mesenchymal stem cells (BMSCs). It was confirmed that the composite scaffold could significantly promote the human umbilical vein endothelial cells (HUVECs) to form the vascular morphology within 6 h in vitro. In vivo, the composite scaffold increased the expression of vascularization and osteogenic related proteins Hif1-α, CD31, OPN, and OCN in the rat femoral defect model, significantly cutting down the time of bone repair. To sum up, this “lotus seedpod” inspired porous bioceramic 3D printed scaffold with internal vascularization functionality has broad application prospects in the future.
A lotus seedpod-inspired internal vascularized 3D printed bioceramic scaffold with internal vascularization and osteogenesis functionalities was successfully constructed. Bioceramic scaffold takes the role of the lotus “coat” while the DFO-liposome-loaded injectable hydrogel microspheres as “lotus seeds”. The “lotus seeds” are injected directly into the scaffold to construct an internally vascularized bioceramic scaffold to promote the repair bone defects. Display omitted
•3D printed bioceramic scaffold with biomimetic structure for blood vessels.•Well-structured vascular network quickly and effectively inside the scaffold.•Promoting the growth of blood vessels inside the scaffold quickly.•Increased the expression of vascularization and osteogenic related proteins Hif1-α.
With the rapid development of telemedicine equipment and information communication technology, telemedicine has developed rapidly and is used widely around the world as a new mode of medical service. ...This new technology has been used widely in China and has benefited a large number of patients. Due to the hospital-centric structure in health sector, resources and patients became increasingly concentrated in hospitals instead of primary care. In this way, telemedicine is a crucial method for government to the inequality of medical resources between urban and rural areas. But little is known about the influence of telemedicine on public primary hospitals in China. The objective of this study is to review the influence of telemedicine on capacity development of respiratory department in public primary hospital in China. A scoping review was conducted using electronic databases including PubMed, Cochrane Library, EMBASE and Google Scholar. Telemedicine has a major impact on the establishment of a complete national health system. The immediate sharing of medical information effectively alleviates the situation of serious information imbalance between doctors and patients. It also guides the public to make rational choice of medical behaviour. In public emergencies, telemedicine can quickly concentrate all kinds of high-quality medical resources to the sites, ensure the safety of people's lives, and provide effective rescue and treatment for the wounded in various special environments. It is conducive to giving full play to the market competition value of public hospital reputation, encouraging hospitals to continuously improve medical technology level, improving medical service quality, actively taking social medical and health responsibility, and this could promote the overall medical and health capacities development.
Clean fracturing fluids are environmentally friendly and could have broad applications in permeability enhancement of coal seams. The hydrophobic chain length of the viscoelastic surfactant (VES) and ...the mixing of VESs with different ionic types have marked effects on the performance of clean fracturing fluids. This paper analyzes the effects of the hydrocarbon chain length of VES and mixing of VESs with different ion types on the pores of coal and discusses the mechanisms controlling the pore changes from a physical and chemical perspective. We found that the coal samples treated with clean fracturing fluid B had the largest porosity change. Adding two methylene groups to the hydrocarbon chain of the cationic VES will increase clay swelling in coal treated with fracturing fluids. Adding 0.1 wt % cocoamidopropyl betaine (zwitterionic VES) to cationic VES fracturing fluids can reduce the extent of clay expansion induced by fracturing fluids. VES with a long hydrocarbon chain has a strong ability to remove kaolinite in hard coal, and the addition of zwitterion VES increases the ability of a clean fracturing fluid to remove kaolinite. These results provide theoretical guidance for the synthesis of new VES molecules and the design of new fracturing fluid formulations.
The overall thermal performance of a solar water heating (SWH) system is significantly affected by the mismatch between the temporal distribution of solar radiation and the heating load. Therefore, a ...favorable correlation between the collector and storage size should be generated based on the dynamic characteristics of the system. This study focuses on the optimal matching of solar collector area with storage volume for an SWH system (with short-term heat storage capability) for a space heating application. A simplified model of an SWH system based on hourly energy flow is established. System control strategy is integrated into the model in a simple manner without sacrificing computing speed. Based on this model, the combined effect of collector area and storage volume on system thermal performance and economy is analyzed, and a simple procedure for determining the optimal system size is illustrated. A case study showed that for an SWH system utilized for space heating application, the optimized ratio between storage volume and collector area is dependent on the total collector area of the system, and is dominated by the requirement of overheating prevention. The minimum storage volume for a specific collector area that can prevent the storage tank from being overheated can be adopted as the optimum storage volume for that collector area. The optimum ratio between storage volume and collector area increases as the collector area increases. Therefore, a trade-off between heat collection and heat loss has to be made while attempting to increase solar fraction by improving collector area.
The precise structural design and reproducible manufacturing advantages of the 3D printed scaffold make it attract attention in clinical applications. However, the inability of scaffolds to achieve ...internal and external co-induced vascularized osteogenesis limits their application. After observing the ingenious and functionalized structural combination of "pinecone", this study prepared hydrogel microspheres encapsulating strontium ranelate (SrR)-dendrimer (PAMAM) as a functionalized "pine nuts" through microfluidic technology. The 3D-printed Polycaprolactone (PCL) scaffold was used as a framework in which hydrogel microspheres and a 3D-printed scaffold were cleverly combined. In this pinecone 3D-scaffold system, the slow release of SrR is beneficial to promote vascularization and osteogenic differentiation inside and outside the scaffold. Furthermore, the rat femoral defect model verified that the pinecone scaffold promoting the formation of internal vascular network, osteogenic differentiation and shortening the bone repair time in vivo. In summary, this pinecone degradable biomimetic composite scaffold with internal osteogenic differentiation and vascular activation functions has great potential for clinical demand in segmental bone defects.
Inspired by the special biological structure of "pine cones", 3D printed porous scaffolds with internal and external co-induced bone repair and angiogenesis have been innovatively constructed, which is expected to open up a new type of functional bone repair scaffold. Display omitted
•The application case of constructed stratified "pinecone" structure bionic 3D-printed scaffold was discussed.•The pinecone 3D scaffold showed excellent vascularization ability and osteoinductive potential in vitro tests.•The pinecone 3D scaffold realized the simultaneous vascularization of the inside and outside of the scaffold, and promote bone reconstruction.
The present study focuses on the influence of the swirling flows on flow behaviors and performance of a radial-flow turbocharger turbine under pulsating inflow condition. To characterize the effects ...of swirling flow, three sets of simulations of the turbine were carried out, which are an unsteady simulation under pulsating swirling inflow, an unsteady simulation under equivalent pulsating uniform inflow, and quasi-steady simulations under uniform inflow. Results proved that swirling flow has a considerable negative influence on turbine instantaneous performance and lead to 2.5% cycle-averaged efficiency reduction under pulsating flow condition. Swirling inflow would lead to significant losses in both the volute and the rotor, while the pulsating inflow leads to higher losses in the rotor and shows little influence on the losses in the volute. The instantaneous efficiency reduction of the turbine could be correlated with the time-varying inlet swirl strength. Under the influence of unsteady inlet swirls, the volute flow field is highly distorted and the free vortex relation is no longer valid. The swirling flow has strong interactions with the wake flow of the volute tongue, leading to additional losses. Relative flow angle at rotor inlet is remarkably reduced and its distribution is significantly distorted. Strong separation flows and passage vortices would appear in the rotor because of the swirling inflow, leading to inferior rotor performance.
...it was shown that EMT is a vital mechanism in the progression of human cancer and resistance of cancers to conventional anti-cancer therapies 8, 9. ...when considering the roles of IL-4Rα and ...IL-13Rα1 in JAK-related cancer progression 2, 3, 5, IL-4Rα and IL-13Rα1 might be involved in the progression of ovarian cancers. ...this study investigated the expression of IL-4Rα and IL-13Rα1 in human ovarian cancer tissues and further evaluated the roles of IL-4Rα and IL-13Rα1 in the progression of ovarian carcinomas in conjunction with the EMT phenotype. ...the overexpression of IL-4Rα or IL-13Rα1 did not influence the expression of mRNA of IL-4Rα or IL-13Rα1 (Figure 1J). ...these data suggest that IL-4Rα and IL-13Rα1 might be involved in the stabilization of each other. Knockdown of IL-4Rα, IL-13Rα1, and both IL-4Rα and IL-13Rα1 significantly decreased tumor size compared with controls (Figure 1M-O). ...when considering the results of the expression of IL-4Rα and IL-13Rα1 in human ovarian cancers and ovarian cancer cells, our results suggest that IL-4Rα and IL-13Rα1 are co-operatively involved in the progression of ovarian carcinomas by stabilizing each other.
Background: FAM83H has been implicated in cancer progression, and PD1 is an important target for anti-cancer immune checkpoint therapy. Recent studies suggest an association between FAM83H expression ...and immune infiltration. However, studies on the roles of FAM83H and its relationship with PD1 in breast carcinomas have been limited. Methods: Immunohistochemical expression of FAM83H and PD1 and their prognostic significance were evaluated in 198 breast carcinomas. Results: The expression of FAM83H in cancer cells was significantly associated with the presence of PD1-positive lymphoid cells within breast carcinoma tissue. Individual and co-expression patterns of nuclear FAM83H and PD1 were significantly associated with shorter survival of breast carcinomas in univariate analysis. In multivariate analysis, the expression of nuclear FAM83H (overall survival, p < 0.001; relapse-free survival, p = 0.003), PD1 (overall survival, p < 0.001; relapse-free survival, p = 0.003), and co-expression patterns of nuclear FAM83H and PD1 (overall survival, p < 0.001; relapse-free survival, p < 0.001) were the independent indicators of overall survival and relapse-free survival of breast carcinoma patients. Conclusions: This study suggests a close association between FAM83H expression and the infiltration of PD1-positive lymphoid cells in breast carcinomas and their expression as the prognostic indicators for breast carcinoma patients, and further studies are needed to clarify this relationship.
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