Статті в журналах з теми "Stress transferring mechanism"
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1
NISHIMURA, YASUSHI, and KOICHI MINAMI. "STRESS TRANSFERRING MECHANISM IN INTERIOR STEEL BEAM-REINFORCED CONCRETE COLUMN JOINT." Journal of Structural and Construction Engineering (Transactions of AIJ) 401 (1989): 77–85. http://dx.doi.org/10.3130/aijsx.401.0_77.
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NISHIMURA, Yasushi, Kohei HORIE, Soichiro OKAMOTO, and Shoko NAGAMINE. "STRESS TRANSFERRING MECHANISM AND RESISTANCE MECHANISM ON CORNER AND EXTERIOR STEEL BEAM - REINFORCED CONCRETE COLUMN JOINTS." Journal of Structural and Construction Engineering (Transactions of AIJ) 78, no. 688 (2013): 1167–74. http://dx.doi.org/10.3130/aijs.78.1167.
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3
Tu, Xiao Qing, Ya Fang Zhang, and Hao Liu. "Effect of Interface Elastic Modulus on Damage Mechanism of the Fiber Reinforced Concrete." Advanced Materials Research 450-451 (January 2012): 1562–66. http://dx.doi.org/10.4028/www.scientific.net/amr.450-451.1562.
Повний текст джерелаАнотація:
This research focuses on the interface’s impact on the macro-mechanics and damage mechanism of the fiber reinforced concrete (FRC). In consideration of the mesoscopic nonhomogeneity of the interface, numerical test has been adopted to simulate failure procedure of fiber reinforced concrete samples. It can, therefore, be concluded, that, the interface elastic modulus have a great impact on the macro-mechanics of the FRC. With interfaces added into FRC, failure could present ductile properties, cracks could be developed horizontally, and then unbonded and slid along the interface. During the process, phenomenons such as interface debonding and sliding, crack deflection, fiber bridging and pulling out could be clearly observed. Under With the premise that strength for interface is adequate for stress transferring, the toughness of the FRC would be enhanced by the interface.
4
Luo, You Xin, Heng Shu Li, Hui Jun Wen, and Yu Zhou. "Research of Advancing Mechanism with Three Circular Arc Equidistant Profile Connection of Drill." Advanced Materials Research 179-180 (January 2011): 895–98. http://dx.doi.org/10.4028/www.scientific.net/amr.179-180.895.
Повний текст джерелаАнотація:
Study the existing advancing mechanism of drill, analyze the disadvantage of the flat key and the spline, and the feature of the three circular arc equidistant profile connection. Taking the common chain advancing mechanism as basis, using three circular arc equidistant curve to make sprocket bore and intermediate shaft external cylindrical fit constitute the three circular arc equidistant profile keyless connection. Then introduce the advancing mechanism with three circular arc equidistant profile connection of drill. Applying Solidworks2010, we created the three-dimensional modeling of the mechanism, which lay the foundation for the further research and application. The new type advancing mechanism has many advantages, such as automatic-centering accurately, convenient in assembling and disassembling, eliminating the stress concentration, simplicity of the fit section，transferring bigger torque, suitable for heavy-loaded rock drill machine.
5
Li, Yong Suo. "The Coupling Effect of Composite Material with Foundation Pile and Soil Mass." Advanced Materials Research 580 (October 2012): 477–80. http://dx.doi.org/10.4028/www.scientific.net/amr.580.477.
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The computer-aided design method is used in modeling for the interaction between pile and geotechnical material soil. The behavior of the shear coupling springs is identical to the shear behavior of a grouted cable. Then a numerical model is founded by FLAC3D, deformation and stress responses are obtained as well as the mechanical response of pile during calculation, whose result reveals the mechanism of pile with soil under the load of gravitation and load transferring mode along pile shaft for different ground surface surcharge load, during simulation, the soil consists of two types, the less consolidated soil and normal consolidated soil, both the negative skin friction stress and positive skin friction stress are studied.
6
Zhang, Yuan Yuan, Li Hua Xu, and Yin Chi. "The Numerical Study on Load-Transferring Model for SFRC Double-Column Combined Six-Pile Caps." Key Engineering Materials 400-402 (October 2008): 321–27. http://dx.doi.org/10.4028/www.scientific.net/kem.400-402.321.
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For discussing the mechanism of load-transferring for reinforced steel fiber reinforced concrete (SFRC) double-column combined six-pile caps, the large-scale general finite element software-ABAQUS is used for the tested SFRC caps with computing in the aspects of modeling, cracking load, limit load, load-deformation curve, distribution of stress in caps and cracks and etc. The results of computing is compared with the result of experiments and the comparison is indicated: The results of computing and experiments are coincided well; The destroy pattern of SFRC double-column combined six-pile caps is sheared damage or punched damage and the model of load-transferring accords with spatial strut-and-tie method (STM); The mixture of steel fiber can improve cracking load and limit load for RC caps, delay the crack for caps, block the cracks’ expansion, and enhance the cap’s ductility.
7
Kuramoto, Hiroshi, and Isao Nishiyama. "Seismic Performance and Stress Transferring Mechanism of Through-Column-Type Joints for Composite Reinforced Concrete and Steel Frames." Journal of Structural Engineering 130, no. 2 (February 2004): 352–60. http://dx.doi.org/10.1061/(asce)0733-9445(2004)130:2(352).
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Wang, Yihan, Fengxin Dong, Hui Chen, Tingying Xu, and Ming Tang. "Effects of Arbuscular Mycorrhizal Fungus on Sodium and Chloride Ion Channels of Casuarina glauca under Salt Stress." International Journal of Molecular Sciences 24, no. 4 (February 12, 2023): 3680. http://dx.doi.org/10.3390/ijms24043680.
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Casuarina glauca is an important coastal protection forest species, which is exposed to high salt stress all year round. Arbuscular mycorrhizal fungi (AMF) can promote the growth and salt tolerance of C. glauca under salt stress. However, the effects of AMF on the distribution of Na+ and Cl− and the expression of related genes in C. glauca under salt stress need to be further explored. This study explored the effects of Rhizophagus irregularis on plant biomass, the distribution of Na+ and Cl−, and the expression of related genes in C. glauca under NaCl stress through pot simulation experiments. The results revealed that the mechanisms of Na+ and Cl− transport of C. glauca under NaCl stress were different. C. glauca took a salt accumulation approach to Na+, transferring Na+ from roots to shoots. Salt accumulation of Na+ promoted by AMF was associated with CgNHX7. The transport mechanism of C. glauca to Cl− might involve salt exclusion rather than salt accumulation, and Cl− was no longer transferred to shoots in large quantities but started to accumulate in roots. However, AMF alleviated Na+ and Cl− stress by similar mechanisms. AMF could promote salt dilution of C. glauca by increasing biomass and the content of K+, compartmentalizing Na+ and Cl− in vacuoles. These processes were associated with the expression of CgNHX1, CgNHX2-1, CgCLCD, CgCLCF, and CgCLCG. Our study will provide a theoretical basis for the application of AMF to improve salt tolerance in plants.
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Urbanavičiūtė, Ieva, Luca Bonfiglioli, and Mario A. Pagnotta. "One Hundred Candidate Genes and Their Roles in Drought and Salt Tolerance in Wheat." International Journal of Molecular Sciences 22, no. 12 (June 15, 2021): 6378. http://dx.doi.org/10.3390/ijms22126378.
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Drought and salinity are major constraints to agriculture. In this review, we present an overview of the global situation and the consequences of drought and salt stress connected to climatic changes. We provide a list of possible genetic resources as sources of resistance or tolerant traits, together with the previous studies that focused on transferring genes from the germplasm to cultivated varieties. We explained the morphological and physiological aspects connected to hydric stresses, described the mechanisms that induce tolerance, and discussed the results of the main studies. Finally, we described more than 100 genes associated with tolerance to hydric stresses in the Triticeae. These were divided in agreement with their main function into osmotic adjustment and ionic and redox homeostasis. The understanding of a given gene function and expression pattern according to hydric stress is particularly important for the efficient selection of new tolerant genotypes in classical breeding. For this reason, the current review provides a crucial reference for future studies on the mechanism involved in hydric stress tolerance and the use of these genes in mark assistance selection (MAS) to select the wheat germplasm to face the climatic changes.
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Xi, Jiaojiao, Xiaoyan Liu, and Zhiqiang Yu. "Investigation of the tensile performance and failure mechanism of carbon–aramid hybrid fibers/epoxy sandwich structure laminates using the UV-thermal synergetic curing mechanism: Experimentation and simulation." Journal of Sandwich Structures & Materials 22, no. 8 (October 25, 2018): 2582–603. http://dx.doi.org/10.1177/1099636218803416.
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The tensile failure mechanism of carbon–aramid hybrid fibers/epoxy sandwich structure laminates was investigated by using experimental and finite element methods. Double curing agents, triarylsulfonium hexafluoroantimonates and triethylene tetramine with a mass ratio of 4:15 were introduced into the laminates. Sandwich structure laminates, with different proportions of hybrid fibers, were cured by UV-initiated anion/cationic dual curing technique. The results showed that the synergetic curing effects of two curing agents were observed under UV irradiation, leading to the better curing of the system, which further plays a positive influence on the mechanical performance. The tensile properties and failure mechanism of the laminates depended on the stacking sequence and fiber volume fractions of the layer structures. The interplay hybrid laminates, containing three alternate plies with fiber contents of 67.7 vol%, presented the optimal tensile performance, and its tensile strength and modulus were 0.82 GPa and 22.09 GPa, respectively. The fracture morphologies revealed that pull-out and debonding of fibers were the main failure mechanism of hybrid laminates. The performance of sandwich structure laminates was determined by the load-carrying capacity of carbon fiber and load-transferring capacity of the aramid fiber and adhesive. The finite element model based on experiments was established to simulate the stress state and failure mechanism of sandwich laminates. The results demonstrated that the stress was better transferred into carbon fibers from the aramid fibers and adhesive, and the relative error rate of maximum stress from finite element analysis and experimental results was less than 5%, which were in reasonable agreement with the experimental results.
11
Huang, Zhi Qiang, Qin Li, Yong Tao Fan, Zhen Qiang Wei, and Hai Yan Zhu. "Study on Mechanism of Hammer Bit and Rock Interaction in Geophysical Prospecting Percussion Drilling." Advanced Materials Research 291-294 (July 2011): 2266–71. http://dx.doi.org/10.4028/www.scientific.net/amr.291-294.2266.
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Percussion drilling has been widely used in oil and gas industry, yet it still has some shortcomings, such as severe damages to drilling tools, low energy transferring efficiency and low rock-fragmenting efficiency. Thus it is necessary to reveal the mechanism of interactions between the hammer bit and rock in geophysical prospecting percussion drilling. Taking account of the coupling effect of the Weight on Bit (WOB), impact force and rotary torque, this paper constructed a Finite Element Method (FEM) model using the finite element analysis software (ANSYS/LS-DYNA) and conducted a computer simulation of bit-rock interaction under rotating and simple impact effect, which showed the rock-fragmenting process of hammer bit and the curves of volume-time and depth-time of craters as well as the effective stress-time curves of the centre tooth, second-row tooth and peripheral tooth. The results showed that: the percussion drilling process under rotating impact effect is characterized as four fundamental processes; the crater depth mainly depends on impact force rather than rotary torque; the crater created under rotating impact effect is twice the volume of that under impact effect; the effective stress of each tooth changes severely: the stress of second-row tooth is the largest, centre tooth the second, and peripheral tooth the smallest. This study provided a guide for the structural optimization of hammer bit and general applications of percussion drilling.
12
Zhang, Zhenting, Zhen Tong, and Xiangqian Jiang. "Development of the Concurrent Multiscale Discrete-Continuum Model and Its Application in Plasticity Size Effect." Crystals 12, no. 3 (February 26, 2022): 329. http://dx.doi.org/10.3390/cryst12030329.
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A concurrent multiscale model coupling discrete dislocation dynamics to the finite element method is developed to investigate the plastic mechanism of materials at micron/submicron length scales. In this model, the plastic strain is computed in discrete dislocation dynamics (DDD) and transferred to the finite element method (FEM) to participate in the constitutive law calculation, while the FEM solves the complex boundary problem for DDD simulation. The implementation of the whole coupling scheme takes advantage of user subroutines in the software ABAQUS. The data structures used for information transferring are introduced in detail. Moreover, a FE mesh-based regularization method is proposed to localize the discrete plastic strain to continuum material points. Uniaxial compression tests of single crystal micropillars are performed to validate the developed model. The results indicate the apparent dependence of yield stress on sample size, and its underlying mechanisms are also analyzed.
13
Cui, Wen, and Zi Jing Wang. "Field Experiment Study on the Bearing Characteristics of Squeezed Branch Pile in Loess Area." Applied Mechanics and Materials 166-169 (May 2012): 1329–32. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.1329.
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The load-transferring mechanism under the action of vertical load and the role of bearing load by bearing disks in loess area were analyzed based on results of field static loading test of the squeezed branch piles. The results indicate that load transfer law of squeezed branch pile is transferred from top to bottom, and load of bearing disks is about 60 percent of the top load of the pile, stress superposition efficiency existed between bearing disks, and the minimum critical spacing of disks is 2D (D is the diameter of the bearing disk), the estimated bearing capacity of the squeezed branch pile is higher than the measured value.
14
Alafiah, A. H., M. Normahira, and M. N. Anas. "A Three Dimensional Finite Element of Anterior Cruciate Ligament Model." Advanced Materials Research 626 (December 2012): 896–901. http://dx.doi.org/10.4028/www.scientific.net/amr.626.896.
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Anterior Cruciate Ligament (ACL) is of the major knee ligament. A three dimensional model that reflects the geometric characteristics of the human ACL developed to explore and analyze finite element parameters such as contact pressure and stress distribution on ACL in response to complex loading conditions. Moreover, various cases studied such as cases involving and uninvolving ligament in order to obtain and analyze the stress and contact pressure relationship between ACL, meniscus and cartilage. It is known that the contact and friction caused by the ACL wrapping around the bone during knee motion played the role of transferring the force from the ACL to the bone, and had a direct effect on the stress distribution of the ACL. Thus, the project lead to better understand the mechanism of injury, to improve the design of ACL reconstruction using suitable material and optimizing rehabilitation protocols by investigation of contact pressure with and without ACL.
15
Huang, Cunhan, Wenhao Dong, Zhengzheng Cao, Yue Wang, Gangjian An, Huanqi Chen, Yunlong Jia, and Qiuyu Pan. "Water Inrush Mechanism of Fault Zone in Karst Tunnel under Fluid-Solid Coupling Field considering Effective Stress." Geofluids 2022 (May 26, 2022): 1–11. http://dx.doi.org/10.1155/2022/4205174.
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At present, the tunnel construction engineering is increasingly transferring to southwest mountainous areas with complex terrain and geological conditions in China and presents a trend of “large buried depth, long tunnel line, high stress, strong karst, high water pressure, complex structure and frequent disasters.” Taking water inrush disaster of karst tunnel fault zone as the research object, an evolutionary mechanical model of rock damage under the coupling action of stress-seepage is proposed in this paper. Besides, based on Comsol Multiphysics numerical software, the tunnel excavation is simulated, and the stress field, seepage field, and rock damage during the excavation are analyzed; thus, the mechanical mechanism of water inrush disaster from tunnel fault in karst area is obtained. The research results indicate that the tunnel excavation is a dynamic construction process, and the construction disturbance redistributes the original rock stress field and changes the state of seepage field. With the increase of excavation steps, the contour distribution of vertical stress ratio near the tunnel face is a circle shape, indicating that the rock mass is obviously disturbed by excavation, and the ratio of principal stress difference of rock mass at arch crown and bottom plate is large. Besides, the fault fissures expand and penetrate under the influence of tunnel excavation disturbance, increasing the permeability of fault zone in karst tunnel. In addition, the water seepage erosion takes away the granular rock mass, and the lithology becomes more weaker, which makes it possible for the occurrence of water inrush disaster in karst tunnel. Therefore, the advanced geological prediction is important in tunnel construction in karst area. The research results can be treated as an important theoretical basis for the prevention and treatment for water inrush disaster of fault zone in karst tunnel.
16
Chen, Xi. "Stress Transferring Mechanism and the Bearing Capacity of Joints between Concrete-Filled Square Steel Tubular Special-Shaped Columns and Steel Beams." Applied Mechanics and Materials 105-107 (September 2011): 926–30. http://dx.doi.org/10.4028/www.scientific.net/amm.105-107.926.
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In recent years, a new type of frame consisting of steel beam and concrete-filled square steel tubular special-shaped column is increasingly widespread. Compared with the joint of ordinary reinforced concrete special shaped frame, the joint between concrete-filled square steel tubular special-shaped columns and steel beams has the advantage of better ductility, higher loading capacity, uncomplicated reinforcement disposing and convenience in construction. This paper indicates that the joint has strong energy dissipation capacity and high loading capacity, and the use of diaphragm is effective to enhance the structural performance of the joints. Stress transferring mechanism in the joints is discussed, and the calculating model of the shear strength of panel zone is established. This study is helpful for further study of the design and use of the joint between concrete-filled square steel tubular special-shaped columns and steel beams.
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Dragotakes, Quigly, Ella Jacobs, Lia Sanchez Ramirez, Olivia Insun Yoon, Caitlin Perez-Stable, Hope Eden, Jenlu Pagnotta, et al. "Bet-hedging antimicrobial strategies in macrophage phagosome acidification drive the dynamics of Cryptococcus neoformans intracellular escape mechanisms." PLOS Pathogens 18, no. 7 (July 11, 2022): e1010697. http://dx.doi.org/10.1371/journal.ppat.1010697.
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The fungus Cryptococcus neoformans is a major human pathogen with a remarkable intracellular survival strategy that includes exiting macrophages through non-lytic exocytosis (Vomocytosis) and transferring between macrophages (Dragotcytosis) by a mechanism that involves sequential events of non-lytic exocytosis and phagocytosis. Vomocytosis and Dragotcytosis are fungal driven processes, but their triggers are not understood. We hypothesized that the dynamics of Dragotcytosis could inherit the stochasticity of phagolysosome acidification and that Dragotcytosis was triggered by fungal cell stress. Consistent with this view, fungal cells involved in Dragotcytosis reside in phagolysosomes characterized by low pH and/or high oxidative stress. Using fluorescent microscopy, qPCR, live cell video microscopy, and fungal growth assays we found that the that mitigating pH or oxidative stress reduced Dragotcytosis frequency, whereas ROS susceptible mutants of C. neoformans underwent Dragotcytosis more frequently. Dragotcytosis initiation was linked to phagolysosomal pH, oxidative stresses, and macrophage polarization state. Dragotcytosis manifested stochastic dynamics thus paralleling the dynamics of phagosomal acidification, which correlated with the inhospitality of phagolysosomes in differently polarized macrophages. Hence, randomness in phagosomal acidification randomly created a population of inhospitable phagosomes where fungal cell stress triggered stochastic C. neoformans non-lytic exocytosis dynamics to escape a non-permissive intracellular macrophage environment.
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Steinchen, Wieland, Jan S. Schuhmacher, Florian Altegoer, Christopher D. Fage, Vasundara Srinivasan, Uwe Linne, Mohamed A. Marahiel, and Gert Bange. "Catalytic mechanism and allosteric regulation of an oligomeric (p)ppGpp synthetase by an alarmone." Proceedings of the National Academy of Sciences 112, no. 43 (October 12, 2015): 13348–53. http://dx.doi.org/10.1073/pnas.1505271112.
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Nucleotide-based second messengers serve in the response of living organisms to environmental changes. In bacteria and plant chloroplasts, guanosine tetraphosphate (ppGpp) and guanosine pentaphosphate (pppGpp) [collectively named “(p)ppGpp”] act as alarmones that globally reprogram cellular physiology during various stress conditions. Enzymes of the RelA/SpoT homology (RSH) family synthesize (p)ppGpp by transferring pyrophosphate from ATP to GDP or GTP. Little is known about the catalytic mechanism and regulation of alarmone synthesis. It also is unclear whether ppGpp and pppGpp execute different functions. Here, we unravel the mechanism and allosteric regulation of the highly cooperative alarmone synthetase small alarmone synthetase 1 (SAS1) fromBacillus subtilis. We determine that the catalytic pathway of (p)ppGpp synthesis involves a sequentially ordered substrate binding, activation of ATP in a strained conformation, and transfer of pyrophosphate through a nucleophilic substitution (SN2) reaction. We show that pppGpp—but not ppGpp—positively regulates SAS1 at an allosteric site. Although the physiological significance remains to be elucidated, we establish the structural and mechanistic basis for a biological activity in which ppGpp and pppGpp execute different functional roles.
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Wang, Junlin, and Zhao Li. "Experimental Study of Thermal Response of Vertically Loaded Energy Pipe Pile." Sustainability 13, no. 13 (July 2, 2021): 7411. http://dx.doi.org/10.3390/su13137411.
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Energy piles are a relatively new technology that have dual function as heat transferring and load bearing. Due to the influence of temperature cycles, additional thermal stress and relative displacement of the pile will be generated; this is different from the load transferring mechanism of the conventional pile. In order to study the thermodynamic characteristics of the energy pipe pile under dual working conditions and temperature cycles, field tests were carried out on the PHC (prestressed high-strength concrete) energy pipe pile without constraining on the top of the piles. Displacement gauges were arranged on the top of the pile, and concrete strain gauges (temperature, strain) were embedded in the pile. The variation laws of temperature, thermal strain, thermal stress, side friction resistance, and displacement of the pile top during the temperature cycling were analyzed. The test results show that the heat exchange system reached a stable state after being heated for 5 days in summer. The average temperature of the pile increased by 15.17 °C, to 34.68 °C; it was low at both ends and high in the middle part. After 5 days in the winter environment, the average temperature of the pile decreased by 10.09 °C, to 9.54 °C, which was high at both ends and low in the middle. The thermal stress was generated inside the pile, and the maximum compressive stress was 3.446 MPa and the maximum tensile stress was 2.69 MPa. The neutral point of the side friction resistance appeared 8 m below the pile top, about 2/3 of the pile length. The maximum negative side friction resistance under the summer condition was 42.06 KPa, the maximum positive side friction resistance under the winter condition was 29.93 KPa, and the lateral resistance of the pile degraded in winter. Under the influence of thermal load, the final pile top displacements in the summer and winter were −0.7 mm (0.175%D) and 0.77 mm (0.193%D), respectively.
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Smith, FW, WA Jackson, and PJV Berg. "Internal Phosphorus Flows During Development of Phosphorus Stress in Stylosanthes hamata." Functional Plant Biology 17, no. 4 (1990): 451. http://dx.doi.org/10.1071/pp9900451.
Повний текст джерелаАнотація:
Partitioning and net transfer of phosphorus between shoots and roots in the tropical forage legume Stylosanthes hamata cv. Verano during the development of phosphorus deficiency has been studied. Plants were stressed by either growing them in dilute flowing culture on continuously maintained external phosphorus concentrations that were inadequate for maximal growth, or by transferring plants of varying phosphorus status to phosphorus-free media. An external phosphorus concentration of 1 �M P was found to be just adequate for maximal growth of S. hamata. Phosphorus stress caused rapid and substantial increases in root weight percentage. It is proposed that this represents an important adaptive mechanism for maximising phosphorus uptake by S. hamata growing in phosphorus-deficient soils. Roots contained the minimum proportion of the plant's phosphorus content when root phosphorus concentrations were 8-10 �mol P g-1 root, and shoot phosphorus concentrations were 16-20 �mol P g-1 shoot. When tissue concentrations were less than these values, plants suffered from phosphorus stress and phosphorus was either preferentially retained by the roots or rapidly transferred from shoots to roots, reducing the growth rates of shoots, but permitting root growth to continue. Upon reducing the external phosphorus supply to plants whose root phosphorus concentrations exceeded 8 to 10 �mol P g-1 root, excess phosphorus was rapidly transferred from the root to the shoot to maintain shoot growth rates. The mobility of phospborus within the plant, and the apparent lack of any delay in transferring phosphorus from shoots to roots as phosphorus stress developed, represent another adaptive feature that is likely to be important to the successful growth of S. hamata in low phosphorus soils. When the phosphorus supply was limited, the plant's resources were directed toward maintaining root growth. Even extremely phosphorus deficient plants, in which shoot growth had ceased, maintained linear rates of root growth. These linear rates were related to the total phosphorus content of the plant. In the latter stages of phosphorus deprivation, linear rates of root growth were maintained by remobilisation of phosphorus from the older parts of the root system to sustain the phosphorus supply to the root meristems.
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Hu, Chengjun, Changliang Han, Lixin Wang, Baofu Zhao, and Houqiang Yang. "Cooperative Control Mechanism of Efficient Driving and Support in Deep-Buried Thick Top-Coal Roadway: A Case Study." Energies 15, no. 12 (June 14, 2022): 4349. http://dx.doi.org/10.3390/en15124349.
Повний текст джерелаАнотація:
For deep-buried thick top-coal roadways under high stress, there exists great difficulty in controlling the stability of the surrounding rock as well as in the necessity for low driving speeds. Taking the return air roadway 20201 (RAR 20201) of the Dahaize Coal Mine as the background, this paper presents a typical engineering case of a deep-buried thick top-coal roadway in a western mine. Through methods such as in situ investigation, theoretical analysis, numerical simulation and engineering practice, we studied the deformation and failure mechanisms of the surrounding rock in a deep-buried high-stress thick top-coal roadway, and revealed the driving speed effect. Results show that compared with shallow buried roadways, the deep-buried thick-roof coal roadway suffers a greater range of damage and failure. The roof damage is so deep that it exceeds the action range of bolts, resulting in the stress transferring to both sides, which affects the stability of the roadway surroundings. The curve of unloading disturbance stress produced by roadway head-on driving is in accordance with the “power exponential” composite function; that is, the faster the driving speed, the less unloading disturbance intensity that is exerted on the roof strata. This paper puts forward targeted cooperative control countermeasures of efficient driving and support in a deep-buried thick top-coal roadway. On one hand, the support efficiency of a single bolt is improved so as to reduce the overall support density; on the other hand, under low support density, the driving-supporting circulation efficiency is also accelerated so as to weaken the unloading disturbance and improve roadway formation speed. Engineering practice shows great control effect of the roadway surrounding rock, and the roadway formation speed is also greatly improved. This research can provide reference for efficient driving and support design in similar deep-buried thick top-coal roadways.
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Cao, Anye, Yaoqi Liu, Siqi Jiang, Qi Hao, Yujie Peng, Xianxi Bai, and Xu Yang. "Numerical Investigation on Influence of Two Combined Faults and Its Structure Features on Rock Burst Mechanism." Minerals 11, no. 12 (December 19, 2021): 1438. http://dx.doi.org/10.3390/min11121438.
Повний текст джерелаАнотація:
With the increase in coal mining depth, engineering geological conditions and the stress environment become more complex. Many rock bursts triggered by two combined faults have been observed in China, but the mechanism is not understood clearly. The focus of this research aims at investigating the influence of two combined faults on rock burst mechanisms. The six types of two combined faults were first introduced, and two cases were utilized to show the effects of two combined faults types on coal mining. The mechanical response of the numerical model with or without combined faults was compared, and a conceptual model was set up to explain the rock burst mechanism triggered by two combined faults. The influence of fault throw, dip, fault pillar width, and mining height on rock burst potential was analyzed. The main control factors of rock burst in six models that combined two faults were identified by an orthogonal experiment. Results show that six combinations of two faults can be identified, including stair-stepping fault, imbricate fault, graben fault, horst fault, back thrust fault, and ramp fault. The particular roof structure near the two combined faults mining preventing longwall face lateral abutment pressure from transferring to deep rock mass leads to stress concentration near the fault areas. Otherwise, a special roof structure causing the lower system stiffness of mining gives rise to the easier gathering of elastic energy in the coal pillars, which makes it easier to trigger a rock burst. There is a nonlinear relationship between fault parameters and static or dynamic load for graben faults mining. The longwall face has the highest rock burst risk when the fault throw is between 6 and 8 m, the fault dip is larger than 65°, the mining height is greater than 6 m, and the coal pillar width is less than 50 m. The stair-stepping, imbricate, horst, and ramp fault compared to the other fault types will produce higher dynamic load stress during longwall retreat. Fault pillar width is the most significant factor for different two combined faults, leading to the rise of static load stress and dynamic proneness.
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Liu, Huanxin, Xingquan Liu, Zhuoying Tan, Yang Liu, and Guilin Li. "Improving the Stability of Subsurface Structures in Deep Metal Mines by Stress and Energy Adjustment: A Case Study." Advances in Civil Engineering 2021 (April 20, 2021): 1–12. http://dx.doi.org/10.1155/2021/6613985.
Повний текст джерелаАнотація:
In deep hard-rock mines, the failure of subsurface structures (e.g., tunnels, stopes, and shafts) has been a significant problem affecting mining safety due to the high-stress environment. In this paper, the mechanism of structural failure and instability is discussed, and optimized excavation methods are proposed for stress control in deep gold mines. Based on the field observation and investigation of the joints distribution and rock failure modes at 800–1200 m depth of several large gold mines and a typical ultradeep borehole (2017 m depth) in northwest Jiaodong Peninsula, three engineering methods for reducing stress, including the stress transferring by mining optimizations, pressure relief by boreholes, and energy release in advance by optimizations of excavation and support, are analyzed by numerical simulation and field monitoring. Results show that stress reduction by excavation alone is limited and the backfill mining method is more conducive to stress transfer than the opening stope method. Roof contacted backfill can produce an unloading zone around the stope and reduce the stress of the surrounding stope. Relief boreholes can reduce the stress concentration of stopes, but the effect of cutting seams generated by presplitting blasting on pressure relief is not significant. The technology “short excavation and short support” releases less energy. By increasing the bench height and the reasonable timing of support by calculating, the elastic strain energy of rock in the shaft is prereleased, which benefits the long-term stability of the shaft.
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Li, Tao, Yumin Zhang, Ying Liu, Xudong Li, Guanglong Hao, Qinghui Han, Lynnette M. A. Dirk, et al. "Raffinose synthase enhances drought tolerance through raffinose synthesis or galactinol hydrolysis in maize and Arabidopsis plants." Journal of Biological Chemistry 295, no. 23 (May 4, 2020): 8064–77. http://dx.doi.org/10.1074/jbc.ra120.013948.
Повний текст джерелаАнотація:
Raffinose and its precursor galactinol accumulate in plant leaves during abiotic stress. RAFFINOSE SYNTHASE (RAFS) catalyzes raffinose formation by transferring a galactosyl group of galactinol to sucrose. However, whether RAFS contributes to plant drought tolerance and, if so, by what mechanism remains unclear. In this study, we report that expression of RAFS from maize (or corn, Zea mays) (ZmRAFS) is induced by drought, heat, cold, and salinity stresses. We found that zmrafs mutant maize plants completely lack raffinose and hyper-accumulate galactinol and are more sensitive to drought stress than the corresponding null-segregant (NS) plants. This indicated that ZmRAFS and its product raffinose contribute to plant drought tolerance. ZmRAFS overexpression in Arabidopsis enhanced drought stress tolerance by increasing myo-inositol levels via ZmRAFS-mediated galactinol hydrolysis in the leaves due to sucrose insufficiency in leaf cells and also enhanced raffinose synthesis in the seeds. Supplementation of sucrose to detached leaves converted ZmRAFS from hydrolyzing galactinol to synthesizing raffinose. Taken together, we demonstrate that ZmRAFS enhances plant drought tolerance through either raffinose synthesis or galactinol hydrolysis, depending on sucrose availability in plant cells. These results provide new avenues to improve plant drought stress tolerance through manipulation of the raffinose anabolic pathway.
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KIMURA, Yoshihiro, Sachi FURUKAWA, Katsunori KANEDA, Toru WATANABE, and Akira WADA. "COMPRESSIVE STRENGTH AND STRESS TRANSFERRING MECHANISM OF JOINT BETWEEN STEEL AND RC COLUMNS FOR STEEL MOMENT RESISTING FRAMES WITH NEW COLUMN SUPPORT SYSTEM." Journal of Structural and Construction Engineering (Transactions of AIJ) 80, no. 712 (2015): 905–15. http://dx.doi.org/10.3130/aijs.80.905.
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Fernando, Veani, Xunzhen Zheng, Yashna Walia, Vandana Sharma, Joshua Letson, and Saori Furuta. "S-Nitrosylation: An Emerging Paradigm of Redox Signaling." Antioxidants 8, no. 9 (September 17, 2019): 404. http://dx.doi.org/10.3390/antiox8090404.
Повний текст джерелаАнотація:
Nitric oxide (NO) is a highly reactive molecule, generated through metabolism of L-arginine by NO synthase (NOS). Abnormal NO levels in mammalian cells are associated with multiple human diseases, including cancer. Recent studies have uncovered that the NO signaling is compartmentalized, owing to the localization of NOS and the nature of biochemical reactions of NO, including S-nitrosylation. S-nitrosylation is a selective covalent post-translational modification adding a nitrosyl group to the reactive thiol group of a cysteine to form S-nitrosothiol (SNO), which is a key mechanism in transferring NO-mediated signals. While S-nitrosylation occurs only at select cysteine thiols, such a spatial constraint is partially resolved by transnitrosylation, where the nitrosyl moiety is transferred between two interacting proteins to successively transfer the NO signal to a distant location. As NOS is present in various subcellular locales, a stress could trigger concerted S-nitrosylation and transnitrosylation of a large number of proteins involved in divergent signaling cascades. S-nitrosylation is an emerging paradigm of redox signaling by which cells confer protection against oxidative stress.
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Li, Guo Chang, Chen Fang, and Hong Ping Yu. "Finite Analysis on Performance of Joint between Gangue Concrete Filled Steel Tubular Column with through Rebar and Gangue Concrete Beam under the Monotonic Loading." Applied Mechanics and Materials 204-208 (October 2012): 3724–30. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.3724.
Повний текст джерелаАнотація:
In order to study the performance of the joint between gangue concrete filled steel tubular column with through rebar and gangue concrete beam under the monotonic loading, element analysis model, which is taken into consideration the material nonlinearity, the geometrical nonlinearity and the contact nonlinearity, is established by finite element analysis software ABAQUS. The results show the force transferring mechanism, the stress distribution, the failure model and the load-displacement curve of the joint under the monotonic loading. It indicates in this paper that the joint between gangue concrete filled steel tubular column with through rebar and gangue concrete beam has such numerous advantages as high bearing capacity, large stiffness and good performance. Meanwhile, the paper provides the calculation evidences to analyze the composite construction of gangue concrete filled steel tubular column and the results can be used to make the analysis on the practical structures.
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Somma, Giuliana, Alessandro Pieretto, and Alberto Dassie'. "Steel to Concrete Bond Transferring in CFST Columns Connected to Beams through the Concrete." Applied Mechanics and Materials 847 (July 2016): 513–20. http://dx.doi.org/10.4028/www.scientific.net/amm.847.513.
Повний текст джерелаАнотація:
An important innovation in structural design in the last thirty years has been the use of steel-concrete composite columns, with particular diffusion of tubular profiles. These elements are known in the technical Literature as concrete filled steel tube (CFST) and the metal profiles that characterize the external jacket are usually circular, square or rectangular.A relevant issue that must be considered is the transfer of shear stresses by adhesion between steel and concrete in composite columns. The problem of adhesion, and thus its formulation, depends primarily on the type of technology used to connect beams to columns. In particular, two different models can be produced: the first case where the beams are connected only to the metal external jacket of the pillar (i.e. steel beams connected with bolted flanges to the column), and the second where beams and columns are connected also in the concrete matrix (i.e. the case of beams in steel-concrete technology, or traditional reinforced concrete beams).International Standards, regarding the problem of adhesion in jacketed columns, only referee to the first connection type, giving a constant value for adhesion coefficient along the transferring length, with no dependence to the size of the section, and indicate transferring lengths independently from the type of beam-to-column connection and the shape of the section. In the Paper are hence proposed expressions that quantify the fundamental values that govern the action transfer mechanism by adhesion in CFST, such as the transfer length, the perimeter of the active transfer and the shear stress distribution, as a function of the slenderness ratio and of the type of connection adopted. All this has been carried in order to produce a model for the estimation of bond stresses for the second of the two construction system mentioned above.
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Guo, Zhibiao, Haohao Wang, Zimin Ma, Pengfei Wang, Xiaohui Kuai, and Xianzhe Zhang. "Research on the Transmission of Stresses by Roof Cutting near Gob Rocks." Energies 14, no. 5 (February 24, 2021): 1237. http://dx.doi.org/10.3390/en14051237.
Повний текст джерелаАнотація:
Pressure relief for roadways retained by roof cutting is essentially caused by stress transfer. In this paper, the stress transfer mechanism of 16011 tail entry with roof cutting in Zhaogu No.1 coal mine is studied from the following two aspects: the change of the tail entry surrounding the rock structure and the interaction between the roadway surrounding rock and supporting structures. It is found by numerical simulation that roof cutting can significantly reduce the magnitude of roadway roof stress, transferring the concentrated stress induced by excavation and mining away from the roadway, and forming an obvious triangle pressure relief area in front of the working face. In the early stage after mining, most of the overburden load is transferred downward through the immediate roof of the roadway. With the movement of overlying strata, the stress, initially transferred to the immediate roof strata, is gradually transferred to the gob, and the calculation formula and influence factors of the transferred stress are derived. In addition, through the establishment of the mechanical model and theoretical calculation of the key rock block of the main roof, the roadside support resistance required to ensure the stability of the main roof block is determined. The field monitoring shows that the lateral pressure coefficient of the roadside caved rocks is 0.36 and the constant resistance and large deformation anchor cable (CRLDAC) and the roadway temporary support play roles of conduction and control in the process of stress transfer, and effectively ensure the stability of surrounding rock during the service life of the retained gob-side entry by roof cutting (RGERC).
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Li, Yongjun, Yuqing Liu, Feihua Wang, and Fei Yang. "Load Transfer Mechanism of Hybrid Pylon Joint with Cells and Bearing Plates." Advances in Civil Engineering 2018 (December 24, 2018): 1–12. http://dx.doi.org/10.1155/2018/6289721.
Повний текст джерелаАнотація:
To investigate the load transfer mechanism of the steel-concrete hybrid pylon joint with cells and bearing plates, a theoretical model based on the continuous elastic interlayer method was established. Both the slip effect at the steel-concrete interface and the local compression effect of the bearing plate were considered in the proposed theoretical model. A segment model test with a 1 : 3 scale was carried out to obtain the strain distribution of the hybrid joint and the relative slip between steel and concrete components. Finite element analysis was implemented on the tested segment model, and the structural performance of the tested hybrid joint was compared with the FEA results. The test and analysis results show that the stress of steel and concrete components is at a lower level, and the relative slip between steel and concrete components is extremely limited. The bearing plates and shear connectors are the two load-transferring components and could transfer 40% and 60% of the vertical force into the lower concrete pylon, respectively. The vertical force of shear connectors is at a much lower magnitude within 0.6 times the length of the hybrid joint from the bearing plate and will increase gradually within 0.6 to 1.0 times the length of the hybrid joint. The FEA results are in good agreement with the model test results, and the maximum shear force difference between the theoretical analysis results and the FEA results is less than 10%, proving that the proposed theoretical model can reasonably predict the shear force distribution at the steel-concrete interface of the hybrid joint. In addition, the stiffness of shear connectors has limited effect on the shear force distribution at the steel-concrete interface.
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Wang, Kang, Xinglong Huang, Haibo Li, Feng Zhang, Jiazhen Li, and Zhijie Zhu. "Surrounding Rock Stresses on a Working Face-End Roof under Mining Influence." Advances in Civil Engineering 2021 (November 10, 2021): 1–11. http://dx.doi.org/10.1155/2021/9915008.
Повний текст джерелаАнотація:
The evolution process of the surrounding rock failure mechanism is studied because of spalling and roof fall accidents at the top corner of longwall top coal caving faces affected by mining and the difficulty of moving the advanced end support. Methods are proposed to improve the stability of surrounding rocks at the top corner of the end including cutting at the top corner of the end, reinforcing the anchor cable, changing the stress distribution of surrounding rocks at the top corner of the end, and transferring the stress concentration area of surrounding rocks to the deeper rock. Field observations of the surrounding rocks at the top corner of the 15107 fully mechanized caving face show that the stress value of the surrounding rocks at the corner between the roof of the return airway and the coal wall of the working face is 28.9 MPa when the surrounding rocks are in a stable state without mining. The stress value of surrounding rocks at the top corner of the end is 32.3 MPa when it is affected by mining, which results in spalling and roof fall. The surrounding rocks are in a stable state when the maximum stress of the surrounding rocks at the top corner of the reinforced anchor cable’s back-end is 26.1 MPa. The results show that cutting of the surrounding rocks at the top corner of the end and the reinforcement of the anchor cable can avoid the spalling and roof fall when the top corner of the end is affected by mining and can ensure that the end support advances and working face moves forward.
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Valkov, Nedyalka, Avash Das, Nathan R. Tucker, Guoping Li, Ane M. Salvador, Mark D. Chaffin, Getulio Pereira De Oliveira Junior, et al. "SnRNA sequencing defines signaling by RBC-derived extracellular vesicles in the murine heart." Life Science Alliance 4, no. 12 (October 18, 2021): e202101048. http://dx.doi.org/10.26508/lsa.202101048.
Повний текст джерелаАнотація:
Extracellular vesicles (EVs) mediate intercellular signaling by transferring their cargo to recipient cells, but the functional consequences of signaling are not fully appreciated. RBC-derived EVs are abundant in circulation and have been implicated in regulating immune responses. Here, we use a transgenic mouse model for fluorescence-based mapping of RBC-EV recipient cells to assess the role of this intercellular signaling mechanism in heart disease. Using fluorescent-based mapping, we detected an increase in RBC-EV–targeted cardiomyocytes in a murine model of ischemic heart failure. Single cell nuclear RNA sequencing of the heart revealed a complex landscape of cardiac cells targeted by RBC-EVs, with enrichment of genes implicated in cell proliferation and stress signaling pathways compared with non-targeted cells. Correspondingly, cardiomyocytes targeted by RBC-EVs more frequently express cellular markers of DNA synthesis, suggesting the functional significance of EV-mediated signaling. In conclusion, our mouse model for mapping of EV-recipient cells reveals a complex cellular network of RBC-EV–mediated intercellular communication in ischemic heart failure and suggests a functional role for this mode of intercellular signaling.
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Strážnická, Michaela, Silvia Marková, Jeremy Searle, and Petr Kotlík. "Playing Hide-and-Seek in Beta-Globin Genes: Gene Conversion Transferring a Beneficial Mutation between Differentially Expressed Gene Duplicates." Genes 9, no. 10 (October 12, 2018): 492. http://dx.doi.org/10.3390/genes9100492.
Повний текст джерелаАнотація:
Increasing evidence suggests that adaptation to diverse environments often involves selection on existing variation rather than new mutations. A previous study identified a nonsynonymous single nucleotide polymorphism (SNP) in exon 2 of two paralogous β-globin genes of the bank vole (Clethrionomys glareolus) in Britain in which the ancestral serine (Ser) and the derived cysteine (Cys) allele represent geographically partitioned functional variation affecting the erythrocyte antioxidative capacity. Here we studied the geographical pattern of the two-locus Ser/Cys polymorphism throughout Europe and tested for the geographic correlation between environmental variables and allele frequency, expected if the polymorphism was under spatially heterogeneous environment-related selection. Although bank vole population history clearly is important in shaping the dispersal of the oxidative stress protective Cys allele, analyses correcting for population structure suggest the Europe-wide pattern is affected by geographical variation in environmental conditions. The β-globin phenotype is encoded by the major paralog HBB-T1 but we found evidence of bidirectional gene conversion of exon 2 with the low-expression paralog HBB-T2. Our data support the model where gene conversion reshuffling genotypes between high- and low- expressed paralogs enables tuning of erythrocyte thiol levels, which may help maintain intracellular redox balance under fluctuating environmental conditions. Therefore, our study suggests a possible role for gene conversion between differentially expressed gene duplicates as a mechanism of physiological adaptation of populations to new or changing environments.
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Zhang, Jicheng, Yong Li, Yu Zheng, and Zhijie Wang. "Seismic Damage Investigation of Spatial Frames with Steel Beams Connected to L-Shaped Concrete-Filled Steel Tubular (CFST) Columns." Applied Sciences 8, no. 10 (September 20, 2018): 1713. http://dx.doi.org/10.3390/app8101713.
Повний текст джерелаАнотація:
Currently, the frame structures with special-shaped concrete-filled steel tubular columns have been widely used in super high-rise buildings. Those structural members can be used to improve architectural space. To investigate the seismic behavior of spatial composite frames that were constructed by connecting steel beams to L-shaped concrete-filled steel tubular (CFST) columns, a finite element analysis (FEA) model using commercial finite element software ABAQUS was proposed to simulate the behavior of the composite spatial frames under a static axial load on columns and a fully-reversed lateral cyclic load applied to frames in this paper. Several nonlinear factors, including geometry and material properties, were taken into account in this FEA model. Four spatial specimens were designed, and the corresponding experiments were conducted to verify the proposed FEA model. Each testing specimen was two-story structure consisting of eight single span steel beams and four L-shaped CFST columns. The test results showed that the proposed FEA model in this paper could evaluate the behavior of the composite spatial frames accurately. Based on the results of the nonlinear analysis, the stress developing progress of columns is investigated. The load transferring mechanism and failure mechanism are also determined. The results are discussed and conclusions about the behavior of those spatial frame structures are presented.
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Tang, Guirong, Qiong Li, Shenghui Xing, Ningning Li, Zheng Tang, Liangliang Yu, Junhui Yan, Xuan Li, and Li Luo. "The LsrB Protein Is Required for Agrobacterium tumefaciens Interaction with Host Plants." Molecular Plant-Microbe Interactions® 31, no. 9 (September 2018): 951–61. http://dx.doi.org/10.1094/mpmi-02-18-0041-r.
Повний текст джерелаАнотація:
Agrobacterium tumefaciens infects and causes crown galls in dicot plants by transferring T-DNA from the Ti plasmid to the host plant via a type IV secretion system. This process requires appropriate environmental conditions, certain plant secretions, and bacterial regulators. In our previous work, a member of the LysR family of transcriptional regulators (LsrB) in Sinorhizobium meliloti was found to modulate its symbiotic interactions with the host plant alfalfa. However, the function of its homolog in A. tumefaciens remains unclear. In this study, we show that the LsrB protein of A. tumefaciens is required for efficient transformation of host plants. A lsrB deletion mutant of A. tumefaciens exhibits a number of defects, including in succinoglycan production, attachment, and resistance to oxidative stress and iron limitation. RNA-sequencing analysis indicated that 465 genes were significantly differentially expressed (upregulation of 162 genes and downregulation of 303 genes) in the mutant, compared with the wild-type strain, including those involved in succinoglycan production, iron transporter, and detoxification enzymes for oxidative stress. Moreover, expression of the lsrB gene from S. meliloti, Brucella abortus, or A. tumefaciens rescued the defects observed in the S. meliloti or A. tumefaciens lsrB deletion mutant. Our findings suggest that a conserved mechanism of LsrB function exists in symbiotic and pathogenic bacteria of the family Rhizobiaceae.
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Hu, Ya Hui, K. H. Lin, S. C. Chang, and Ming Chang. "Design of a Compliant Micromechanism for Optical-Fiber Alignment." Key Engineering Materials 381-382 (June 2008): 141–44. http://dx.doi.org/10.4028/www.scientific.net/kem.381-382.141.
Повний текст джерелаАнотація:
The optical-fiber alignment system is a critical role on micro/nano precision engineering. In this paper, the design and fabrication of a novel, six-axis compliant nano-stage which uses flexure hinge and negative Poisson’s Ratio is presented. Every single axis is a designed planar geometry, so it is easily fabricated via laser cutting processes that enable cost down to achieve batch products. The material of six-axis mechanism is aluminum. The micromechanism consists of six trapeziform displacement structures and two hexagonal plates which are on the top and bottom. The displacement structures includes of a signal layer flexure hinge toggle mechanism stage and asymmetrical multi-layer flexure hinge toggle mechanism stage. The computer simulation of the transferring behavior was performed with a commercial package, named SolidWorks ANSYS@. The model states of stress, strain and the displacement of ratio can be estimated. The experiment was carried out with Piezoelectric(PZT) actuators and LVDT which drives and measures the displacement. Comparison of the simulation and experimental result between the single-axis and six-axis stage are presented. The results shown that the displacement of ratio is 32 times as the single-axis structures. The system maximum displacement of vertical translation, horizontal translation, tilt angle and rotational angle is 50 µm, 50 µm, 0.5° and 0.5°. In experimental, the results not only demonstrate that this micromechanism of flexure hinge and negative Poisson’s Ratio increases the displacement of ratio and reduces the size of system, but can also be applied on the optical-fiber alignment system.
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Gerasimova, Elena L., Elena R. Gazizullina, Maria V. Borisova, Dinara I. Igdisanova, Egor A. Nikiforov, Timofey D. Moseev, Mikhail V. Varaksin, Oleg N. Chupakhin, Valery N. Charushin, and Alla V. Ivanova. "Design and Antioxidant Properties of Bifunctional 2H-Imidazole-Derived Phenolic Compounds—A New Family of Effective Inhibitors for Oxidative Stress-Associated Destructive Processes." Molecules 26, no. 21 (October 29, 2021): 6534. http://dx.doi.org/10.3390/molecules26216534.
Повний текст джерелаАнотація:
The synthesis of inhibitors for oxidative stress-associated destructive processes based on 2H-imidazole-derived phenolic compounds affording the bifunctional 2H-imidazole-derived phenolic compounds in good-to-excellent yields was reported. In particular, a series of bifunctional organic molecules of the 5-aryl-2H-imidazole family of various architectures bearing both electron-donating and electron-withdrawing substituents in the aryl fragment along with the different arrangements of the hydroxy groups in the polyphenol moiety, namely derivatives of phloroglucinol, pyrogallol, hydroxyquinol, including previously unknown water-soluble molecules, were studied. The structural and antioxidant properties of these bifunctional 5-aryl-2H-imidazoles were comprehensively studied. The redox transformations of the synthesized compounds were carried out. The integrated approach based on single and mixed mechanisms of antioxidant action, namely the AOC, ARC, Folin, and DPPH assays, were applied to estimate antioxidant activities. The relationship “structure-antioxidant properties” was established for each of the antioxidant action mechanisms. The conjugation effect was shown to result in a decrease in the mobility of the hydrogen atom, thus complicating the process of electron transfer in nearly all cases. On the contrary, the conjugation in imidazolyl substituted phloroglucinols was found to enhance their activity through the hydrogen transfer mechanism. Imidazole-derived polyphenolic compounds bearing the most electron-withdrawing functionality, namely the nitro group, were established to possess the higher values for both antioxidant and antiradical capacities. It was demonstrated that in the case of phloroglucinol derivatives, the conjugation effect resulted in a significant increase in the antiradical capacity (ARC) for a whole family of the considered 2H-imidazole-derived phenolic compounds in comparison with the corresponding unsubstituted phenols. Particularly, conjugation of the polyphenolic subunit with 2,2-dimethyl-5-(4-nitrophenyl)-2H-imidazol-4-yl fragment was shown to increase ARC from 2.26 to 5.16 (104 mol-eq/L). This means that the considered family of compounds is capable of exhibiting an antioxidant activity via transferring a hydrogen atom, exceeding the activity of known natural polyphenolic compounds.
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Hong, Zhenyu, Xiaoli Yu, Zhenpeng He, and Guichang Zhang. "The multi-objective optimization of the damaged aircraft trailer based on a dynamic model." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 232, no. 11 (October 23, 2017): 1481–93. http://dx.doi.org/10.1177/0954407017730439.
Повний текст джерелаАнотація:
A damaged aircraft trailer is an essential piece of airport emergency rescue equipment which is made up of frames and multiple suspensions. As a load–force transferring mechanism, the suspension bears heavy loads which can cause fatigue damage. Therefore, reducing the maximum stress of the suspension is necessary to improve the vehicle performance. Besides, lightweight design should be considered to reduce energy consumption. Thus, lighter suspension which can bear more pressure is the optimization objective of this research. A multi-objective optimization method was carried out to analyze the suspension arm of a damaged aircraft trailer. Firstly, to investigate the dynamic characteristics and the reliability of the damaged aircraft trailer, a detailed three combined damaged aircraft trailers model was built. Based on the flexible-rigid coupled method, dynamic simulation of the damaged aircraft trailer was conducted in MSC.ADAMS. Then a suspension model was established, and the stress under different loads was measured to verify the accuracy of the finite element suspension arm model by experiments. Based on the design of experiment method, the effect of suspension arm parameters were obtained to build the approximate models. Besides, the influences of some effect parameters on optimal objectives were analyzed based on the surface response method. During the optimization process, a non-dominated sorting genetic algorithm II was adopted to optimize the mass and stress of the suspension arm. The results show that the mass of the suspension arm is reduced from 146.81 kg to 126.69 kg, which is a reduction of 14%. The maximum von Mises stress is changed from 325 MPa to 297 MPa, which is a decrease of 8.6%. This optimal method can be extended to the overall vehicle, which has an important significance in the whole damaged aircraft trailer characteristics improvement design.
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Plecitá-Hlavatá, Lydie, Hana Engstová, Jan Ježek, Blanka Holendová, Jan Tauber, Lucie Petrásková, Vladimír Křen та Petr Ježek. "Potential of Mitochondria-Targeted Antioxidants to Prevent Oxidative Stress in Pancreatic β-cells". Oxidative Medicine and Cellular Longevity 2019 (21 травня 2019): 1–16. http://dx.doi.org/10.1155/2019/1826303.
Повний текст джерелаАнотація:
Pancreatic β-cells are vulnerable to oxidative stress due to their low content of redox buffers, such as glutathione, but possess a rich content of thioredoxin, peroxiredoxin, and other proteins capable of redox relay, transferring redox signaling. Consequently, it may be predicted that cytosolic antioxidants could interfere with the cytosolic redox signaling and should not be recommended for any potential therapy. In contrast, mitochondrial matrix-targeted antioxidants could prevent the primary oxidative stress arising from the primary superoxide sources within the mitochondrial matrix, such as at the flavin (IF) and ubiquinone (IQ) sites of superoxide formation within respiratory chain complex I and the outer ubiquinone site (IIIQ) of complex III. Therefore, using time-resolved confocal fluorescence monitoring with MitoSOX Red, we investigated various effects of mitochondria-targeted antioxidants in model pancreatic β-cells (insulinoma INS-1E cells) and pancreatic islets. Both SkQ1 (a mitochondria-targeted plastoquinone) and a suppressor of complex III site Q electron leak (S3QEL) prevented superoxide production released to the mitochondrial matrix in INS-1E cells with stimulatory glucose, where SkQ1 also exhibited an antioxidant role for UCP2-silenced cells. SkQ1 acted similarly at nonstimulatory glucose but not in UCP2-silenced cells. Thus, UCP2 can facilitate the antioxidant mechanism based on SkQ1+ fatty acid anion- pairing. The elevated superoxide formation induced by antimycin A was largely prevented by S3QEL, and that induced by rotenone was decreased by SkQ1 and S3QEL and slightly by S1QEL, acting at complex I site Q. Similar results were obtained with the MitoB probe, for the LC-MS-based assessment of the 4 hr accumulation of reactive oxygen species within the mitochondrial matrix but for isolated pancreatic islets. For 2 hr INS-1E incubations, some samples were influenced by the cell death during the experiment. Due to the frequent dependency of antioxidant effects on metabolic modes, we suggest a potential use of mitochondria-targeted antioxidants for the treatment of prediabetic states after cautious nutrition-controlled tests. Their targeted delivery might eventually attenuate the vicious spiral leading to type 2 diabetes.
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Jia, Yanling, Yongxu Xia, Xindong Chen, Yongdi Zhou, Xingbo Han, and Shaowen Zhou. "Force and Deformation Characteristics during the Reconstruction and Expansion of Shallow Single-Tube Tunnels into Large-Span Multiarch Tunnels." Advances in Materials Science and Engineering 2019 (December 24, 2019): 1–13. http://dx.doi.org/10.1155/2019/2783784.
Повний текст джерелаАнотація:
At present, there are an ever-increasing number of tunnel expansion projects in China. Studying the mechanical properties of the expanded tunnels is of great significance for guiding their safe construction. Through model testing and numerical simulation, the mechanical properties of a double-arch tunnel constructed through the expansion of the middle pilot heading from an existing single-tube tunnel were studied. The variation characteristics of the surface subsidence, surrounding rock stress, and stress and strain of the middle partition wall and lining during the tunnel reconstruction and expansion were investigated. The mechanism for transferring stress and strain between the left and right tunnel tubes was studied by a numerical simulation method. The results showed that the surface subsidence caused by the excavation of the left (i.e., the subsequent) tunnel tube was larger, and the maximum surface subsidence occurred at the right (i.e., the first) tunnel tube. The surrounding rock on the middle wall was the sensitive part of the tunnel excavation, the stress of the surrounding rock at the left spandrel of the right tunnel tube fluctuated and exhibited the most complex variation, and the stress of the surrounding rock at the right spandrel of the left tunnel tube exhibited the largest variation. The excavation of the left tunnel tube had a great influence on the forces of the middle partition wall and the lining structure of the right tunnel tube, the middle partition wall was subjected to eccentric compression towards the left tunnel tube, and the stress at the left spandrel under the initial support of the right tunnel tube exhibited complex variations. The excavation of the left and right tunnel tubes had a great influence on the stability of the surrounding rock, as well as on the force-induced deformation of the middle partition wall and the support structure, within the width of the single tunnel tube span behind the tunnel working face. Due to the different construction sequences, the stress and strain at the symmetric measurement points of the middle partition wall, as well as the left and right tunnel support structures, were very different.
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Shih, Kao-Shang, Ching-Shiow Tseng, Chia-Ching Lee, Tung-Wu Lu, Sheng-Mou Hou, and Shang-Chih Lin. "EFFECTS OF DISTAL NAIL-HOLE DIMENSION AND WALL THICKNESS ON THE FEMORAL NAILING STRESSES — FINITE-ELEMENT ANALYSIS." Biomedical Engineering: Applications, Basis and Communications 21, no. 03 (June 2009): 177–85. http://dx.doi.org/10.4015/s1016237209001234.
Повний текст джерелаАнотація:
Background. For the available systems, the two paired nail holes at the distal femoral portion were of identical size and shape. However, the higher incidence of the first nail-hole failure was reported at the medial than lateral side. In practice, the nail was initially stabilized by the screw insertion into the first hole from the lateral-to-medial side. If the lateral first hole was adequately strengthened, the larger nail-hole diameter could ease to insert the screws into the lateral hole. Methods. The finite-element method was used to investigate the effect of the configuration of the lateral first hole on the screw insertion and stress distribution of the distal nailing system. The distal nail-hole thickness was increased and its edge was intentionally chamfered to increase its effectively projected area onto the sagittal plane. There were eight variations of the nail-hole configuration in the parametric analyses. Findings. The deflected nail diagonally contacts the screws at the medial first and lateral second nail-screw sites. The medial first hole was the most stressed and the stress of the medial second hole was the least. The increase in the nail-hole thickness significantly reduces the concentrated stresses of all four holes, thus allowing the lateral first nail-hole diameter to be increased without the strength loss at that site. The enlargement and chamfer of the lateral first hole significantly increase the effective nail-hole projected area and potentially facilitate the screw insertion. Comparatively, the size and shape re-design of the lateral first hole induced the minor increase in stress values of the other holes and screws. Interpretation. In nature, the load-transferring mechanism between the distal nail-screw interfaces was the point-contact problem. If the wall-thickness, diameter, and chamfer of the lateral first hole were well-controlled, this re-design decreases the stress at the medial first distal hole where most failures occur and renders the overall system mechanically safer and more surgically effective.
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Gu, Qian, Cheng Fang Sun, and Shao Min Peng. "Experimental Study on Deep Four-Pile Caps with Different Reinforcement Layouts Based on 3D Strut-and-Tie Analogy." Key Engineering Materials 400-402 (October 2008): 917–22. http://dx.doi.org/10.4028/www.scientific.net/kem.400-402.917.
Повний текст джерелаАнотація:
Based on 3D strut-and-tie analogy developed for analyzing the load-transferring mechanism of deep pile cap, this paper focuses on the effect of different longitudinal reinforcement layouts at the lower part of cap on the mechanical behaviors of deep four-pile cap. Besides a common layout of uniformly distributed reinforcement by the flexural theory, three different layouts of concentrated reinforcement over piles were designed by 3D strut-and-tie analogy. All specimens were limited in same reinforcement percentages, dimensions, materials and test procedures. Four specimens with the scale ratio of 1/5 were tested under the statically incremental gravity loading. The load capacity, deflection, strain of longitudinal reinforcement of specimens were measured, and the failure mode, crack propagation, deformation of specimens and stress distribution of reinforcement were analyzed. Through comparisons of the test results among all specimens, it was found that deep pile cap failed in shear and corner-pile punching whether with concentrated or uniform reinforcement, and the reinforcement concentrated over each two adjacent piles, similar to the tension bars in the strut-and-tie model, had considerable advantages than common uniform reinforcement layout. The ultimate strength of deep pile cap with concentrated reinforcement was significantly increased, while the improvement of deformation resistance and brittleness of deep pile cap was limited. According to above findings, the appropriate reinforcement layouts for deep pile cap were suggested in this paper.
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Tikhonov, G. M., and S. B. Ponomarev. "LONELINESS AS ONE OF THE STRESS FACTORS OF THE PENITENTIARY SYSTEM." Intelligence. Innovations. Investment, no. 2 (2022): 134–41. http://dx.doi.org/10.25198/2077-7175-2022-2-134.
Повний текст джерелаАнотація:
Abstract. The article is devoted to the problem of the phenomenon of prison loneliness. The relevance of this study is due to the fact that the phenomenon of prison loneliness underlies penitentiary stress, as a complex psychophysiological reaction of the body to being in a penitentiary space. One of the functions of the execution of punishment as a response of society to the unlawful actions of a criminal is punishment for a committed crime, which acts in the form of induction of mental suffering of a person as a result of his artificial separation from the usual social environment, the creation of prison loneliness. At the same time, the effect of transferring suffering from the body of the criminal to his soul, noted by M. Foucault, is realized. The purpose of the work involves the analysis of the phenomenon of loneliness in the conditions of places of deprivation of liberty. The main characteristic features of prison loneliness are described. It is shown that the punishment of a criminal by imprisonment, his forcible isolation from the mainstream society is based on the mechanism of creating artificial prison deprivation. It is noted that one of the attributes of punishing a criminal is the intentional creation of a special type of loneliness — prison, causing a high level of penitentiary stress. The article shows that two types of prison loneliness can be considered. The first one is proposed to be called “physical loneliness”, which is created by the physical isolation of the convict. At the heart of the generation of suffering of the personality of this type of loneliness is the effect of a violation of the human need inherent at the gene level to communicate with other members of society. This type of prison loneliness leads to a change in the psyche of the prisoner, the loss of communication skills, his slow emotional and mental degradation. The second type of prison loneliness (loneliness in the crowd) is characterized by the fact that in conditions of prison isolation, the prisoner is almost never left alone and is constantly under the influence of carriers of the penitentiary subculture, which has a powerful negative impact on the personality of the person serving the sentence. In an environment where interests are reduced to the satisfaction of vital needs, and interpersonal aggression is the norm of behavior, negative emotions prevail in the prisoner’s sense of self, the dominant of which will be a feeling of loneliness.
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Chovancova, Barbora, Sona Hudecova, Lubomira Lencesova, Petr Babula, Ingeborg Rezuchova, Adela Penesova, Marian Grman, Roman Moravcik, Michal Zeman, and Olga Krizanova. "Melatonin-Induced Changes in Cytosolic Calcium Might be Responsible for Apoptosis Induction in Tumour Cells." Cellular Physiology and Biochemistry 44, no. 2 (2017): 763–77. http://dx.doi.org/10.1159/000485290.
Повний текст джерелаАнотація:
Background/Aims: Melatonin is a hormone transferring information about duration of darkness to the organism and is known to modulate several signaling pathways in the cells, e.g. generation of endoplasmic reticulum stress, oxidative status of the cells, etc. Melatonin has been shown to exert antiproliferative and cytotoxic effects on various human cancers. We proposed that this hormone can differently affect tumour cells and healthy cells. Methods: We compared the effect of 24 h melatonin treatment on calcium transport (by fluorescent probes FLUO-3AM and Rhod-5N), ER stress (determined as changes in the expression of CHOP, XBP1 and fluorescently, using Thioflavin T), ROS formation (by CellROX® Green/Orange Reagent) and apoptosis induction (by Annexin-V-FLUOS/propidiumiodide) in two tumour cell lines – ovarian cancer cell line A2780 and stable cell line DLD1 derived from colorectal carcinoma, with non-tumour endothelial cell line EA.hy926. Results: Melatonin increased apoptosis in both tumour cell lines more than twice, while in EA.hy926 cells the apoptosis was increased only by 30%. As determined by silencing with appropriate siRNAs, both, type 1 sodium/calcium exchanger and type 1 IP3 receptor are involved in the apoptosis induction. Antioxidant properties of melatonin were significantly increased in EA.hy926 cells, while in tumour cell lines this effect was much weaker. Conclusion: Taken together, melatonin has different antioxidative effects on tumour cells compared to non-tumour ones; it also differs in the ability to induce apoptosis through the type 1 sodium/calcium exchanger, and type 1 IP3 receptor. Different targeting of calcium transport systems in tumour and normal, non-tumour cells is suggested as a key mechanism how melatonin can exert its anticancer effects. Therefore, it might have a potential as a novel therapeutic implication in cancer treatment.
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Ji, Zhanling, Yunhua Li, Rui Xi, and Juntao Jia. "Elastic-plastic analysis for wet multidisc brake during repeated braking." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 230, no. 17 (August 9, 2016): 2968–81. http://dx.doi.org/10.1177/0954406215605334.
Повний текст джерелаАнотація:
To reveal the mechanism and evolution laws of the braking performance declining from heat load in the repeated braking applied for wet multidisc brake, a finite element analysis was carried out by using the bidirectional thermal-structure coupling method. Based on the fundamental principles of the energy conservation and virtual work principle, the elemental equations between temperature and heat load, and deformation displacement and load with heat transferring boundary conditions and heat–structure interaction were derived. Taking a steel disk in the brake for example, the deformation state of its elements, and the starting time, the location, the severity, and evolution laws of the plastic deformation were analyzed and demonstrated by using dimensionless stress distribution contours. The area in contact along the interface and the ratio of the element numbers to produce plastic deformation to the total element numbers on the steel disk were described by contact ratio and plasticity ratio, respectively. Moreover, the results under the repeated braking case were compared with that under the lasting braking case, which indicates that the influence of the temperature load on the performance declining of the repeated braking case is much lower than one of the lasting braking case, and the temperature is lower than 40 K and the plasticity ratio is smaller than 0.35 after the braking time is longer than 350 s. The conducted finite element analyses provided the theoretical fundamentals for the design and the application of the brake in the heavy type of trucks.
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Wu, Wenqing, Hui Zhang, Zheng Liu, and Yunpeng Wang. "Numerical Analysis on Transverse Splicing Structure for the Widening of a Long Multi-Span Highway Concrete Continuous Box Girder Bridge." Materials 15, no. 19 (September 30, 2022): 6805. http://dx.doi.org/10.3390/ma15196805.
Повний текст джерелаАнотація:
For the bridge widening of long multi-span highway concrete continuous box girder with a conventional splicing structure, due to the large longitudinal difference deformation by concrete shrinkage and creep between the existing and new ones, the widened structure will have an overlarge bending deformation after widening, especially an obvious transverse deformation at the end of girder, which will lead to structural damage to the newly widened structure. To effectively absorb the difference deformation mentioned above, this study proposes a novel transverse splicing structure based on the folding effect of a corrugated steel plate (CSP) (hereinafter referred to as “the CSP splicing structure”). Then, a finite element structural analysis was performed on the mechanical properties of the widened structure with the CSP splicing structure, and compared to those of a widened structure adopting the conventional concrete splicing mode, to clarify the transverse load transferring mechanism of the structure. Finally, by conducting a sensitivity analysis on CSP thickness, corrugation length, splicing stitch width, and other structural parameters, a sound parameter combination scheme was put forward. According to the research results, to ensure effective utilization of the CSP folding effect, the corrugation pattern direction of CSP should be set as horizontal, and the wave angle as the degree of 90°. In addition, it mitigated the transverse tensile stress to effectively avoid concrete cracking feasibility on the top flange of the box girder at the end of the girder. This study offers a feasible way of avoiding the structural damage produced by an excess transverse deformation at the end of the girder after bridge widening of a long multi-span concrete continuous box girder.
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Sandrini, Sara M., Raminder Shergill, Jonathan Woodward, Remya Muralikuttan, Richard D. Haigh, Mark Lyte, and Primrose P. Freestone. "Elucidation of the Mechanism by Which Catecholamine Stress Hormones Liberate Iron from the Innate Immune Defense Proteins Transferrin and Lactoferrin." Journal of Bacteriology 192, no. 2 (October 9, 2009): 587–94. http://dx.doi.org/10.1128/jb.01028-09.
Повний текст джерелаАнотація:
ABSTRACT The ability of catecholamine stress hormones and inotropes to stimulate the growth of infectious bacteria is now well established. A major element of the growth induction process has been shown to involve the catecholamines binding to the high-affinity ferric-iron-binding proteins transferrin (Tf) and lactoferrin, which then enables bacterial acquisition of normally inaccessible sequestered host iron. The nature of the mechanism(s) by which the stress hormones perturb iron binding of these key innate immune defense proteins has not been fully elucidated. The present study employed electron paramagnetic resonance spectroscopy and chemical iron-binding analyses to demonstrate that catecholamine stress hormones form direct complexes with the ferric iron within transferrin and lactoferrin. Moreover, these complexes were shown to result in the reduction of Fe(III) to Fe(II) and the loss of protein-complexed iron. The use of bacterial ferric iron uptake mutants further showed that both the Fe(II) and Fe(III) released from the Tf could be directly used as bacterial nutrient sources. We also analyzed the transferrin-catecholamine interactions in human serum and found that therapeutically relevant concentrations of stress hormones and inotropes could directly affect the iron binding of serum-transferrin so that the normally highly bacteriostatic tissue fluid became significantly more supportive of the growth of bacteria. The relevance of these catecholamine-transferrin/lactoferrin interactions to the infectious disease process is considered.
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Malorni, W., F. Iosi, M. T. Santini, and U. Testa. "Menadione-induced oxidative stress leads to a rapid down-modulation of transferrin receptor recycling." Journal of Cell Science 106, no. 1 (September 1, 1993): 309–18. http://dx.doi.org/10.1242/jcs.106.1.309.
Повний текст джерелаАнотація:
It has been demonstrated that perturbation of oxidative balance plays an important role in numerous pathological states as well as in physiological modifications leading to aging. In order to evaluate the role of the oxidative state in cells, biochemical and ultrastructural studies were carried out on K562 and HL-60 cell cultures. Particular attention was given to the transferrin receptor, which plays an important role in cellular iron metabolism. In order to evaluate if oxidative stress influences the transferrin receptor regulation process, the free-radical inducer menadione was used. The results obtained seem to indicate that oxidative stress is capable of inducing a rapid and specific down-modulation of the membrane transferrin receptor due to a block of receptor recycling on the cell surface, without affecting ligand-binding affinity. These effects were observed in the early stages of menadione treatment and before any typical signs of subcellular damage, including surface blebbing, a well-known cytopathological marker of menadione-induced injury. The mechanisms underlying such phenomena appear to be related to cytoskeletal protein thiol group oxidation as well as to the perturbation of calcium homeostasis, both induced by menadione. It is thus hypothesized that the data reported here represent a specific example of a general mechanism by which cell surface receptor expression and recycling can be influenced by oxidative balance.
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MATSUI, Tomoya, and Hiroshi KURAMOTO. "STRESS TRANSFERRING MECHANISMS OF COMPOSITE CES BEAM-COLUMN JOINTS UNDER LATERAL LOAD REVERSALS." Journal of Structural and Construction Engineering (Transactions of AIJ) 73, no. 630 (2008): 1401–7. http://dx.doi.org/10.3130/aijs.73.1401.
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Medica, Davide, Rossana Franzin, Alessandra Stasi, Giuseppe Castellano, Massimiliano Migliori, Vincenzo Panichi, Federico Figliolini, Loreto Gesualdo, Giovanni Camussi, and Vincenzo Cantaluppi. "Extracellular Vesicles Derived from Endothelial Progenitor Cells Protect Human Glomerular Endothelial Cells and Podocytes from Complement- and Cytokine-Mediated Injury." Cells 10, no. 7 (July 2, 2021): 1675. http://dx.doi.org/10.3390/cells10071675.
Повний текст джерелаАнотація:
Glomerulonephritis are renal inflammatory processes characterized by increased permeability of the Glomerular Filtration Barrier (GFB) with consequent hematuria and proteinuria. Glomerular endothelial cells (GEC) and podocytes are part of the GFB and contribute to the maintenance of its structural and functional integrity through the release of paracrine mediators. Activation of the complement cascade and pro-inflammatory cytokines (CK) such as Tumor Necrosis Factor α (TNF-α) and Interleukin-6 (IL-6) can alter GFB function, causing acute glomerular injury and progression toward chronic kidney disease. Endothelial Progenitor Cells (EPC) are bone-marrow-derived hematopoietic stem cells circulating in peripheral blood and able to induce angiogenesis and to repair injured endothelium by releasing paracrine mediators including Extracellular Vesicles (EVs), microparticles involved in intercellular communication by transferring proteins, lipids, and genetic material (mRNA, microRNA, lncRNA) to target cells. We have previously demonstrated that EPC-derived EVs activate an angiogenic program in quiescent endothelial cells and renoprotection in different experimental models. The aim of the present study was to evaluate in vitro the protective effect of EPC-derived EVs on GECs and podocytes cultured in detrimental conditions with CKs (TNF-α/IL-6) and the complement protein C5a. EVs were internalized in both GECs and podocytes mainly through a L-selectin-based mechanism. In GECs, EVs enhanced the formation of capillary-like structures and cell migration by modulating gene expression and inducing the release of growth factors such as VEGF-A and HGF. In the presence of CKs, and C5a, EPC-derived EVs protected GECs from apoptosis by decreasing oxidative stress and prevented leukocyte adhesion by inhibiting the expression of adhesion molecules (ICAM-1, VCAM-1, E-selectin). On podocytes, EVs inhibited apoptosis and prevented nephrin shedding induced by CKs and C5a. In a co-culture model of GECs/podocytes that mimicked GFB, EPC-derived EVs protected cell function and permeselectivity from inflammatory-mediated damage. Moreover, RNase pre-treatment of EVs abrogated their protective effects, suggesting the crucial role of RNA transfer from EVs to damaged glomerular cells. In conclusion, EPC-derived EVs preserved GFB integrity from complement- and cytokine-induced damage, suggesting their potential role as therapeutic agents for drug-resistant glomerulonephritis.