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Marine collagen (MC) has recently attracted more attention in tissue engineering as a biomaterial substitute due to its significant role in cellular signaling mechanisms, especially in mesenchymal stem cells (MSCs). However, the actual signaling mechanism of MC in MSC growth, which is highly influenced by their molecular pattern, is poorly understood. Hence, we investigated the integrin receptors (α1β1, α2β1, α10β1, and α11β1) binding mechanism and proliferation of MCs (blacktip reef shark collagen (BSC) and blue shark collagen (SC)) compared to bovine collagen (BC) on MSCs behavior through functionalized collagen molecule probing for the first time. The results showed that BSC and SC had higher proliferation rates and accelerated scratch wound healing by increasing migratory rates of MSCs. Cell adhesion and spreading results demonstrated that MC had a better capacity to anchor MSCs and maintain cell morphology than controls. Living cell observations showed that BSC was gradually assembled by cells into the ECM network within 24 h. Interestingly, qRT-PCR and ELISA revealed that the proliferative effect of MC was triggered by interacting with specific integrin receptors such as α2β1, α10β1, and α11β1 of MSCs. Accordingly, BSC accelerated MSCs’ growth, adhesion, shape, and spreading by interacting with specific integrin subunits (α2 and β1) and thereby triggering further signaling cascade mechanisms.

Many waterflooding oil fields, injecting water into an oil-bearing reservoir for pressure maintenance, are in their middle to late stages of development. To explore the geological conditions and improve oilfield recovery of the most important well group of the Hu 136 block, located on the border areas of three provinces (Henan, Shandong, and Hebei), Zhongyuan Oilfield, Sinopec, central China, a 14C cross-well tracer monitoring technology was developed and applied in monitoring the development status and recognize the heterogeneity of oil reservoirs. The tracer response in the production well was tracked, and the water drive speed, swept volume of the injection fluid were obtained. Finally, the reservoir heterogeneity characteristics, such as the dilution coefficient, porosity, permeability, and average pore-throat radius, were fitted according to the mathematical model of the heterogeneous multi-layer inter-well theory. The 14C-AMS technique developed in this work is expected to be a potential analytical method for evaluating underground reservoir characteristics and providing crucial scientific guidance for the mid to late oil field recovery process.

Traditional proper orthogonal decomposition (POD)-Galerkin projection for reduced-order models (ROMs) of fluid flows is based on a fixed domain. The current method removes this limitation by consid...

Skin disease is one of the most common diseases. Due to the intricate categories of skin diseases, their symptoms being very similar in the early stage, and the lesion samples being extremely unbalanced, their classification is challenging. At the same time, under the conditions of limited data, the generalization ability of a single reliable convolutional neural network model is weak, the feature extraction ability is insufficient, and the classification accuracy is low. Therefore, in this paper, we proposed a convolutional neural network model for skin disease classification based on model fusion. Through model fusion, deep and shallow feature fusion, and the introduction of an attention module, the feature extraction capacity of the model was strengthened. In addition, a series of works such as model pre-training, data augmentation, and parameter fine-tuning were conducted to upgrade the classification performance of the model. The experimental results showed that when working on our private dataset dominated by acne-like skin diseases, our proposed model outperformed the two baseline models of DenseNet201 and ConvNeXt_L by 4.42% and 3.66%, respectively. On the public HAM10000 dataset, the accuracy and f1-score of the proposed model were 95.29% and 89.99%, respectively, which also achieved good results compared with other state-of-the-art models.

With the slowdown of the urbanization rate and new buildings in China, the old houses have different degrees of safety problems. Therefore, the importance of reinforcement and reconstruction of old houses has become increasingly apparent. This paper intends to study statically indeterminate trusses in buildings. Based on the finite element analysis, the paper compares the influence of the method of increasing section area on the original truss structure by establishing the reconstruction scheme of the same statically indeterminate truss. The numerical simulation results show that the ultimate bearing capacity of the structure is increased to achieve the purpose of strengthening.

With the extensive application of offshore power plants and attaching importance of nuclear reactor system in marine industry, the narrow rectangular channels used for the compact heat exchanger in marine nuclear plant have drawn growing attention in recent years. Compared to some conventional pipes, the narrow rectangular channels boost the heat removal capacity efficiently and present the characteristics of compact layout, which have extensive application in compact heat exchangers. A significant number of experiments have been conducted on this topic. In this paper, a comprehensive historical review for narrow rectangular thermal-hydraulic characteristics under marine conditions is proposed, including an expansive number of experimental and numerical studies in open literatures for recent decade. The pressure drop and heat transfer characteristics are chiefly clarified in this paper. Additionally, the closely related studies of authors published in the last years are summarized in detailed. The followings are the significant aspects of this paper for dominant contents: (1) on the basis of a compilation of numerous distinguishing criterions, the definitions of narrow rectangular channels and marine motions are presented. (2) the flow characteristics of pressure drop and heat transfer characteristics in narrow rectangular channels under marine conditions are reviewed and summarized, basing on the authors’ published research achievements.

HighlightsThis study developed a mathematical relationship accounting for the production rate of phosphine.The effect of temperature on phosphine sorption into wheat is described mathematically.A computational fluid dynamics (CFD) model was built to predict the phosphine concentration in fumigated grain.Experiments were conducted to validate the CFD model.Abstract. Phosphine gas (PH3) is widely used as a fumigant for stored product insect infestations due to its relatively low price and the near absence of residual chemical on the grain. Understanding the behavior of phosphine gas inside the fumigated space is crucial to maintaining a lethal dosage and protecting stored grain from subsequent insect damage. Phosphine is available either in gas form or is produced from a solid material, as pellets or tablets, that reacts with water in the air. The solid form is the most commonly used; however, limited information is available on the rate of phosphine gas generated from the solid material. In this study, a mathematical equation was formulated, based on previous studies in the literature, to describe the gas generation rate. This equation was incorporated into a computational model using ANSYS Fluent 19.1, a commercial software for computational fluid dynamics (CFD) analysis. The computational model developed here allows prediction of the phosphine concentration within a fumigated grain bulk. The PH3 sorption was included in the model. The effect of temperature on the sorption rate was investigated based on published data, and the rate change due to temperature was characterized. The gas generated by a single pellet was measured in laboratory experiments in a 0.208 m3 sealed barrel. The measurements confirmed the CFD results with an error of 0.3%, 0.9%, and 7.2% for three different configurations. The deviations seen between the experimental replicates increased the error and show the need for further investigation of the effects of temperature, grain age and history, leakage, and other factors. Keywords: CFD, Evolution rate, Phosphine, Sorption.

Background. Yisui Qinghuang powder (YSQHP) is an effective traditional Chinese medicinal formulation used for the treatment of myelodysplastic syndromes (MDS). However, its pharmacological mechanism of action is unclear. Materials and Methods. In this study, the active compounds of YSQHP were screened using the traditional Chinese medicine systems pharmacology (TCMSP) and HerDing databases, and the putative target genes of YSQHP were predicted using the STITCH and DrugBank databases. Then, we further screened the correlative biotargets of YSQHP and MDS. Finally, the compound-target-disease (C-T-D) network was conducted using Cytoscape, while GO and KEGG analyses were conducted using R software. Furthermore, DDI-CPI, a web molecular docking analysis tool, was used to verify potential targets and pathways. Finally, binding site analysis was performed to identify core targets using MOE software. Results. Our results identified 19 active compounds and 273 putative target genes of YSQHP. The findings of the C-T-D network revealed that Rb1, CASP3, BCL2, and MAPK3 showed the most number of interactions, whereas indirubin, tryptanthrin, G-Rg1, G-Rb1, and G-Rh2 showed the most number of potential targets. The GO analysis showed that 17 proteins were related with STPK activity, PUP ligase binding, and kinase regulator activity. The KEGG analysis showed that PI3K/AKT, apoptosis, and the p53 pathways were the main pathways involved. DDI-CPI identified the top 25 proteins related with PI3K/AKT, apoptosis, and the p53 pathways. CASP8, GSK3B, PRKCA, and VEGFR2 were identified as the correlative biotargets of DDI-CPI and PPI, and their binding sites were found to be indirubin, G-Rh2, and G-Rf. Conclusion. Taken together, our results revealed that YSQHP likely exerts its antitumor effects by binding to CASP8, GSK3B, PRKCA, and VEGFR2 and by regulating the apoptosis, p53, and PI3K/AKT pathways.

An adjoint-based optimization is applied to study the thrust performance of a pitching–rolling ellipsoidal plate in a uniform stream at Reynolds number 100. To achieve the highest thrust, the optim...

The effect of dynamic spanwise bending on the vortex dynamics of an accelerating flat plate is studied with experiments and numerical simulations. A flat plate, held at an angle of attack of 30 degrees, is accelerated from rest to Reynolds number 2400. It was bent dynamically along the span in a controlled manner with a bending ratio of 0.65. We find that a dynamic spanwise bending induces a change in the effective shear layer velocity along the span's bent part and creates spanwise vorticity convection. As a result, the growth of circulation in the leading-edge-vortex gets delayed along the bent part, and the final circulation is smaller than the no bending case.

Traditional dynamic mode decomposition (DMD) methods inevitably involve matrix inversion, which often brings in numerical instability and spurious modes. In this paper, a new algorithm is derived to solve DMD as a general eigenvalue problem, which is then computed with a projection to a subspace with minimal errors in terms of least-squares (LS) or total-least-squares (TLS), leading to a more stable DMD algorithm, named DMD-LS or DMD-TLS, respectively. A new residual criterion, along with a typical energy criterion, is then proposed to select the most dynamically relevant DMD eigenvalues and modes. The accuracy and robustness of DMD-LS and DMD-TLS algorithms are demonstrated by application to the direct simulation data of the three-dimensional flow past a fixed long cylinder, which covers the entire evolution from the asymptotic periodic to the completely periodic stages of the flow. The connection between DMD modes and Floquet modes commonly used in stability studies was demonstrated through the DMD analysis of the asymptotic periodic data for the secondary instability of the flow.

Belt dryers have been widely used in the drying process, a key process for quality control, of aquatic feed or pet food. An important criterion to measure the drying quality of a dryer is moisture uniformity, which directly affected by the distribution of airflow field. The airflow field is determined by several factors, including conveyor position and feed thickness. In this study, effects of conveyor positions on airflow distribution in three types of belt dryers are simulated and compared using computational fluid dynamic analysis. The simulation results show that the conveyor positions had significant effects on airflow rate in a two-layer belt dryer. Furthermore, the simulation provided three different airflow fields for three dryer models, and an optimal dryer model was selected for further analysis of air velocity on feed surface.

Feed drying which uses airflow to remove moisture from the feed is a key process affecting the quality of aquatic feed and pet food. However, uneven distribution of airflow velocity in drying chamber results in moisture non-uniformity of dried feed, which is the main reason for low efficient drying. In this study, computational fluid dynamic technology is utilized to simulate effects of feed thickness on the distribution of airflow flow field in a single-conveyor belt dryer. Results show that feed thickness has significant effects on airflow velocity in a single-conveyor belt dryer. Furthermore, an optimal value of feed thickness is recommended based on the current setting.

To design efficient flapping wing micro air vehicles (FWMAVs), a comprehensive sizing method based on theoretical and statistical analyses is proposed and experimentally verified. This method is composed of five steps including defining and analyzing the MAV mission, determining the flying modes, defining the wing shape and aspect ratio of the wing, applying the constraint analysis based on the defined mission, and estimating the weights of the electrical and structural components of the bio-inspired flapping wing micro air vehicle. To define the vehicle mission and flight plan, path analysis is performed based on the defined mission, the speed of cruise and turning, the turning radius and climatic conditions in the flight area. Following the defined mission analysis, the appropriate modes of flying (i.e., flapping, gliding, hovering, bounding, and soaring) for the flapping wing bird are recognized. After that, the wing shape and the wing aspect ratio are determined based on the defined flight modes. To estimate the wing loading, a constraint analysis is exploited in which flight equitation is simulated based on the modes and missions of the flight. Along with the four listed steps, a statistical method is employed to estimate the FWMAV weight for a well-defined mission. Based on the offered method for wing sizing of flapping wings, a FWMAV named Thunder I has been designed, fabricated, and tested. This developed methodology is very beneficial by giving guidelines for the design of efficient bio-inspired FWMAVs.