• Journal of Microbiology and Biotechnology
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• v.32 no.5
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• pp.645-656
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• 2022

Gossypol, a natural phenolic aldehyde present in cotton plants, was originally used as a means of contraception, but is currently being studied for its anti-proliferative and anti-metastatic effects on various cancers. However, the intracellular mechanism of action regarding the effects of gossypol on pancreatic cancer cells remains unclear. Here, we investigated the anti-cancer effects of gossypol on human pancreatic cancer cells (BxPC-3 and MIA PaCa-2). Cell counting kit-8 assays, annexin V/propidium iodide staining assays, and transmission electron microscopy showed that gossypol induced apoptotic cell death and apoptotic body formation in both cell lines. RNA sequencing analysis also showed that gossypol increased the mRNA levels of CCAAT/enhancer-binding protein homologous protein (CHOP) and activating transcription factor 3 (ATF3) in pancreatic cancer cell lines. In addition, gossypol facilitated the cleavage of caspase-3 via protein kinase RNA-like ER kinase (PERK), CHOP, and Bax/Bcl-2 upregulation in both cells, whereas the upregulation of ATF was limited to BxPC-3 cells. Finally, a three-dimensional culture experiment confirmed the successful suppression of cancer cell spheroids via gossypol treatment. Taken together, our data suggest that gossypol may trigger apoptosis in pancreatic cancer cells via the PERK-CHOP signaling pathway. These findings propose a promising therapeutic approach to pancreatic cancer treatment using gossypol.

• Computers and Concrete
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• v.31 no.5
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• pp.385-394
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• 2023

Displacement is an important element for evaluating the stability and failure mechanism of hydraulic structures. Digital image correlation (DIC) is a useful technique to measure a three-dimensional displacement field using two cameras without any contact with test material. The objective of this study is to evaluate the behavior of stacked geotextile tubes using the DIC technique. Geotextile tubes are stacked to build a small-scale temporary dam model to exclude water from a specific area. The horizontal and vertical displacements of four stacked geotextile tubes are monitored using a dual camera system according to the upstream water level. The geotextile tubes are prepared with two different fill materials. For each dam model, the interface layers between upper and lower geotextile tubes are either unreinforced or reinforced with a cementitious binder. The displacement of stacked geotextile tubes is measured to analyze the behavior of geotextile tubes. Experimental results show that as upstream water level increases, horizontal and vertical displacements at each layer of geotextile tubes initially increase with water level, and then remain almost constant until the subsequent water level. The displacement of stacked geotextile tubes depends on the type of fill material and interfacial reinforcement with a cementitious binder. Thus, the proposed DIC technique can be effectively used to evaluate the behavior of a hydraulic structure, which consists of geotextile tubes.

• Journal of Veterinary Science
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• v.24 no.4
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• pp.53.1-53.12
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• 2023

Background: Mammalian orthoreovirus type 3 (MRV3), which is responsible for gastroenteritis in many mammalian species including pigs, has been isolated from piglets with severe diarrhea. However, the use of pig-derived cells as an infection model for swine-MRV3 has rarely been studied. Objectives: This study aims to establish porcine intestinal organoids (PIOs) and examine their susceptibility as an in vitro model for intestinal MRV3 infection. Methods: PIOs were isolated and established from the jejunum of a miniature pig. Established PIOs were characterized using polymerase chain reaction (PCR) and immunofluorescence assays (IFAs) to confirm the expression of small intestine-specific genes and proteins, such as Lgr5, LYZI, Mucin-2, ChgA, and Villin. The monolayered PIOs and three-dimensional (3D) PIOs, obtained through their distribution to expose the apical surface, were infected with MRV3 for 2 h, washed with Dulbecco's phosphate-buffered saline, and observed. Viral infection was confirmed using PCR and IFA. We performed quantitative real-time reverse transcription-PCR to assess changes in viral copy numbers and gene expressions linked to intestinal epithelial genes and antiviral activity. Results: The established PIOs have molecular characteristics of intestinal organoids. Infected PIOs showed delayed proliferation with disruption of structures. In addition, infection with MRV3 altered the gene expression linked to intestinal epithelial cells and antiviral activity, and these effects were observed in both 2D and 3D models. Furthermore, viral copy numbers in the supernatant of both models increased in a time-dependent manner. Conclusions: We suggest that PIOs can be an in vitro model to study the infection mechanism of MRV3 in detail, facilitating pharmaceutical development.

• Geomechanics and Engineering
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• v.35 no.4
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• pp.395-409
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• 2023

Long-span suspension bridges have tunnel anchor systems to maintain stable cables. More investigations are required to determine how closely tunnel excavation beneath the tunnel anchor impacts the stability of the tunnel anchor. In order to investigate the impact of the adjacent tunnel's excavation on the stability of the tunnel anchor, a large-span suspension bridge tunnel anchor is utilised as an example in a three-dimensional numerical simulation approach. In order to explore the deformation control mechanism, orthogonal tests are employed to pinpoint the major impacting elements. The construction of an advanced pipe shed, strengthening the primary support. Moreover, according to the findings the grouting reinforcement of the surrounding rock, have a significant control effect on the settlement of the tunnel vault and plug body. However, reducing the lag distance of the secondary lining does not have such big influence. The greatest way to control tunnel vault settling is to use the grout reinforcement, which increases the bearing capacity and strength of the surrounding rock. This greatly minimizes the size of the tunnel excavation disturbance area. Advanced pipe shed can not only increase the surrounding rock's bearing capacity at the pipe shed, but can also prevent the tunnel vault from connecting with the disturbance area at the bottom of the anchorage tunnel, reduce the range of shear failure area outside the anchorage tunnel, and have the best impact on the plug body's settlement control.

• Journal of the Korean Regional Science Association
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• v.40 no.1
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• pp.111-127
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• 2024

Our study investigates the impact of paternalistic leadership on organizational citizenship behavior in the Chinese context. First, we explore whether the benevolent, moral, and authoritative dimensions of paternalistic leadership positively influence organizational citizenship behavior. Second, we examine the mediating role of affective commitment. Third, we investigate whether power distance orientation and follower's age moderate the paternalistic leadership-affective commitment-organizational citizenship behavior mechanism. The results confirm the positive effects of the three sub-dimensions. We also confirm power distance orientation and follower's age moderate the effect of benevolent and moral aspects of paternalistic leadership. These underscore the importance of a dimensional analysis of paternalistic leadership. Theoretical and practical implications are also suggested.

• Korean Journal of Applied Biomechanics
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• v.34 no.2
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• pp.81-92
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• 2024

Objective: The purpose of this study was to analyze the impact acceleration, shock attenuation and biomechanical variables at various running speed. Method: 20 subjects (height: 176.15 ± 0.63 cm, weight: 70.95 ± 9.77 kg, age: 27.00 ± 4.65 yrs.) participated in this study. The subjects ran at four different speeds (2.5 m/s, 3.0 m/s, 3.5 m/s, 4.0 m/s). Three-dimensional accelerometers were attached to the distal tibia, sternum and head. Gait parameters, biomechanical variables (lower extremity joint angle, moment, power and ground reaction force) and acceleration variables (impact acceleration, shock attenuation) were calculated during the stance phase of the running. Repeated measures ANOVA was used with an alpha level of .05. Results: In gait parameters, decreased stance time, increasing stride length and stride frequency with increasing running speed. And at swing time 2.5 m/s and 4.0 m/s was decreased compared to 3.0 m/s and 3.5 m/s. Biomechanical variables statistically increased with increasing running speed except knee joint ROM, maximum ankle dorsiflexion moment, and maximum hip flexion moment. In acceleration variables as the running speed increased (2.5 m/s to 4.0 m/s), the impact acceleration on the distal tibia increased by more than twice, while the sternum and head increased by approximately 1.1 and 1.2 times, respectively. And shock attenuation (tibia to head) increased as the running speed increased. Conclusion: When running speed increases, the magnitude and increasing rate of sternum and head acceleration are lower compared to the proximal tibia, while shock attenuation increases. This suggests that limiting trunk movement and increasing lower limb movement effectively reduce impact from increased shock. However, to fully understand the body's mechanism for reducing shock, further studies are needed with accelerometers attached to more segments to examine their relationship with kinematic variables.

• Geomechanics and Engineering
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• v.36 no.6
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• pp.545-561
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• 2024

Piled raft foundation has become widely used in the recent years because it can increase bearing capacity of foundation with control settlement. The design for a piled raft in terms vertical load and lateral load need to understands contribution load behavior to raft and pile in piled raft foundation system. The load-bearing behavior of the piled raft, especially concerning lateral loads, is highly complex and challenge to analyze. The complex mechanism of piled rafts can be clarified by using three dimensional (3-D) Finite Element Method (FEM). Therefore, this paper focuses on free-standing head pile group, on-ground piled raft, and embedded raft for the piled raft foundation systems. The lateral resistant of piled raft foundation was investigated in terms of relationship between vertical load, lateral load and displacement, as well as the lateral load sharing of the raft. The results show that both vertical load and raft position significantly impact the lateral load capacity of the piled raft, especially when the vertical load increases and the raft embeds into the soil. On the same condition of vertical settlement and lateral displacement, piled raft experiences a substantial demonstrates a higher capacity for lateral load sharing compared to the on-ground raft. Ultimately, regarding design considerations, the piled raft can reliably support lateral loads while exhibiting behavior within the elastic range, in which it is safe to use.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2029-2038
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• 2024

A deep understanding of the characteristics and mechanism of geyser boiling and capillary pumping is necessary to optimize a high-temperature sodium heat pipe. In this work, the Volume of Fluid (VOF) two-phase model and the capillary force model in the mesh wick were used to model the complex phase change and fluid flow in the heat pipe. Computational Fluid Dynamics (CFD) simulations successfully predicted the process of bubble nucleation, growth, aggregation, and detachment from the wall in the liquid pool of the evaporation section of the heat pipe in horizontal and tilted states, as well as the reflux phenomenon of capillary suction within the wick. The accuracy and stability of the capillary force model within the wick were verified. In addition, the causes of geyser boiling in heat pipes were analyzed by extracting the oscillation distribution of heat pipe wall temperature. The results show that adding the capillary force model within the wick structure can reasonably simulate the liquid backflow phenomenon at the condensation; Under the horizontal and inclined operating conditions of the heat pipe, the phenomenon of local dry-out will occur, resulting in a sharp increase in local temperature. The speed of bubble detachment and the timely reflux of liquid sodium (condensate) replenishment in the wick play a vital role in the geyser temperature oscillation of the tube wall. The numerical simulation method and the results of this study are anticipated to provide a good reference for the investigation of geyser boiling in high-temperature heat pipes.

• Geomechanics and Engineering
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• v.38 no.4
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• pp.381-395
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• 2024

With the wide application of urban subway tunnels, the foundation pits of new stations and existing subway tunnels are becoming increasingly close, and even zero-distance close-fitting construction has taken place. To optimize the construction support scheme, the existing tunnel's vertical displacement is theoretically analyzed using the two-stage analysis method to understand the action mechanism of the construction of zero-distance deep large foundation pits on both sides of the existing stations; a three-dimensional numerical calculation is also performed for further analysis. First, the additional stress field on the existing tunnel caused by the unloading of zero-distance foundation pits on both sides of the tunnel is derived based on the Mindlin stress solution of a semi-infinite elastic body under internal load. Then, considering the existing subway tunnel's joints, shear stiffness, and shear soil deformation effect, the tunnel is regarded as a Timoshenko beam placed on the Kerr foundation; a sixth-order differential control equation of the tunnel under the action of additional stress is subsequently established for solving the vertical displacement of the tunnel. These theoretical calculation results are then compared with the numerical simulation results and monitoring data. Finally, an optimized foundation pit support scheme is obtained considering the pit corner effect and external corner failure mode. The research shows a high consistency between the monitoring data,analytical and numerical solution, and the closer the tunnel is to the foundation pit, the more uplift deformation will occur. The internal corner of the foundation pit can restrain the deformation of the tunnel and the retaining structure, while the external corner can cause local stress concentration on the diaphragm wall. The proposed optimization scheme can effectively reduce construction costs while meeting the safety requirements of foundation pit support structures.

• Geomechanics and Engineering
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• v.38 no.3
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• pp.319-334
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• 2024

The current theories on the interaction between surrounding rock and support in deep-buried tunnels do not consider the form of pre-reinforcement support or the flexibility of primary support, leading to a discrepancy between theoretical solutions and practical applications. To address this gap, a comprehensive mechanical model of the tunnel with pre-reinforced rock was established in this study. The equations for internal stress, displacement, and the radius of the plastic zone in the surrounding rock were derived. By understanding the interaction mechanism between flexible support and surrounding rock, the three-dimensional construction analysis solution of the tunnel could be corrected. The validity of the proposed model was verified through numerical simulations. The results indicate that the reduction of pre-deformation significantly influences the final support pressure. The pre-reinforcement support zone primarily inhibits pre-deformation, thereby reducing the support pressure. The support pressure mainly affects the accelerated and uniform movement stage of the surrounding rock. The generation of support pressure is linked to the deformation of the surrounding rock during the accelerated movement stage. Furthermore, the strength of the pre-reinforcement zone of the surrounding rock and the strength of the shotcrete have opposite effects on the support pressure. The parameters of the pre-reinforcement zones and support materials can be optimized to achieve a balance between surrounding rock deformation, support pressure, cost, and safety. Overall, this study provides valuable insights for predicting the deformation of surrounding rock and support pressure during the dynamic construction of deep-buried weak rock tunnels. These findings can guide engineers in improving the construction process, ensuring better safety and cost-effectiveness.