Dissecting Causal Relationships Between Gut Microbiota, Blood Metabolites, and Stroke: A Mendelian Randomization Study

Wang Qi,Dai Huajie,Hou Tianzhichao,Hou Yanan,Wang Tiange,Lin Hong,Zhao Zhiyun,Li Mian,Zheng Ruizhi,Wang Shuangyuan,Lu Jieli,Xu Yu,Liu Ruixin,Ning Guang,Wang Weiqing,Bi Yufang,Zheng Jie,Xu Min 대한뇌졸중학회 2023 Journal of stroke Vol.25 No.3

Background and Purpose We investigated the causal relationships between the gut microbiota (GM), stroke, and potential metabolite mediators using Mendelian randomization (MR). Methods We leveraged the summary statistics of GM (n=18,340 in the MiBioGen consortium), blood metabolites (n=115,078 in the UK Biobank), and stroke (cases n=60,176 and controls n=1,310,725 in the Global Biobank Meta-Analysis Initiative) from the largest genome-wide association studies to date. We performed bidirectional MR analyses to explore the causal relationships between the GM and stroke, and two mediation analyses, two-step MR and multivariable MR, to discover potential mediating metabolites. Results Ten taxa were causally associated with stroke, and stroke led to changes in 27 taxa. In the two-step MR, <i>Bifidobacteriales</i> order, <i>Bifidobacteriaceae</i> family, <i>Desulfovibrio</i> genus, apolipoprotein A1 (ApoA1), phospholipids in high-density lipoprotein (HDL_PL), and the ratio of apolipoprotein B to ApoA1 (ApoB/ApoA1) were causally associated with stroke (all <i>P</i><0.044). The causal associations between <i>Bifidobacteriales</i> order, <i>Bifidobacteriaceae</i> family and stroke were validated using the weighted median method in an independent cohort. The three GM taxa were all positively associated with ApoA1 and HDL_PL, whereas <i>Desulfovibrio</i> genus was negatively associated with ApoB/ApoA1 (all <i>P</i><0.010). Additionally, the causal associations between the three GM taxa and ApoA1 remained significant after correcting for the false discovery rate (all q-values <0.027). Multivariable MR showed that the associations between <i>Bifidobacteriales</i> order, <i>Bifidobacteriaceae</i> family and stroke were mediated by ApoA1 and HDL_PL, each accounting for 6.5% (<i>P</i>=0.028) and 4.6% (<i>P</i>=0.033); the association between <i>Desulfovibrio</i> genus and stroke was mediated by ApoA1, HDL_PL, and ApoB/ApoA1, with mediated proportions of 7.6% (<i>P</i>=0.019), 4.2% (<i>P</i>=0.035), and 9.1% (<i>P</i>=0.013), respectively. Conclusion The current MR study provides evidence supporting the causal relationships between several specific GM taxa and stroke and potential mediating metabolites.

Microstructure, Mechanical Properties and Strain Hardening Behavior of Alternative α/β Mg-Li Composite Sheets Prepared by Accumulative Roll Bonding

Huajie Wu,Yang Wang,Ruizhi Wu,Feng Zhong,Dan Wang,Legan Hou,Jinghuai Zhang 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.5

To improve comprehensive mechanical properties of Mg-Li alloy, alternative α/β Mg-Li composite sheets with a bimodalgrainedstructure were prepared by accumulative roll bonding (ARB). The microstructure, texture, mechanical propertiesand strain hardening behavior of the alternative α/β Mg-Li composite sheets were studied. The bimodal grain structure,with ultrafine grains (about 0.79 μm) in the α alloy and coarse grains (about 53.28 μm) in the β alloy, can be observed in thecomposite sheet. The dominant texture of α-Mg and β-Li alloys is {0002} basal texture and {110} texture, respectively. Inthe α alloy, the basal texture decreases gradually with the increase of ARB pass, and the non-basal texture is formed in thesheet processed by 5-pass ARB. The dislocation density of the composite sheet gradually increases and approaches saturationafter 3-pass ARB process due to the balance between dislocation accumulation in the ARB process and dislocationannihilation in dynamic recovery. The sheet processed by 3-pass ARB has the preferable strength and plasticity, with yieldstrength, ultimate tensile strength, elongation of 204 MPa, 216 MPa, 22.73%, respectively. Compared with the as-annealedalloys before ARB, the strain hardening rate of the ARB composite sheets increases gradually at low stress (stage II). Mg-Lisheets produced by ARB process remain a high plasticity because of the longer softening stage (stage III), which is mainlycontributed to the synergistic effect of the bimodal grain structure and the activation of non-basal texture.

Mechanical and Thermodynamic Properties of Unidirectional Flax Fiber Reinforced CNT Modified Epoxy Composites

Hongguang Wang,Lanjie Yang,Huajie Guo,Yagebai Zhao,Jianing Zhao 한국섬유공학회 2019 Fibers and polymers Vol.20 No.6

In this paper, the mechanical and thermodynamic properties of diglycidyl ether of bisphenol-F (DGEBF) epoxyresin and flax fiber FRP composites, which was modified with multi-walled carbon nanotubes (MWCNTs) were studied. Themechanical property tests show significant improvements in the tensile strength (48.7 %), tensile modulus (25.2 %) at1.0 wt.% of MWCNTs. DMTA test reveals that mixture of 1.0 wt.% MWCNTs into the epoxy resin increases 10.68 K of Tg,which is in accordance to the simulated results from molecular dynamics. These improvements in mechanical andthermodynamic properties are attributed to the balanced effect of stress concentration and radiation. The mechanical andthermodynamic properties of flax fiber FRP composites are improved with the addition of MWCNTs. This study is expectedto provide an opportunity to develop high performance of natural fiber FRP composites.

Investigation on crack propagation properties of flange-stiffened plate structure in a sleeve

Qinglin Lian,Huaji Wang,Xiaowei Ren,Xiaochen Fan,Dingshi Li,Jinbiao Zhao,Long Ju,Guodong Zhang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.11

A 3D FE model has been developed to investigate the crack propagation properties of flange-stiffened plate structure in a sleeve used for loading transition, according to practical observations of the crack morphology. The stress intensity factor (SIF) was applied to analyze the crack propagation properties along crack tip in different positions of the sleeve;simulation models including either one crack or multiple cracks were studied. Results showed that crack formation had insignificant influence on the structural effective stress and deformation variations. The faces of the crack formed at the bolt hole edge were opened, meanwhile the crack possessed the highest potential to grow, while cracks in the connecting fillet between flange and stiffened plate and the flange mounting interface were less likely to propagate. Compared with the one-crack model, when multiple cracks co-existed there were limited changes on the crack respective propagation properties.

Advances of molecular dynamics simulation in tribochemistry and lubrication investigations: A review

Jiaqi He,Huajie Tang,Chenglong Wang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.126 No.-

As a hot topic in recent years, molecular dynamics (MD) simulation has become an effective tool in tribochemistryand lubrication investigations, which provides unique insight on dealing with these issues fromatomic scale. This review paper presents an overview of recent MD simulation studies on revealing the frictionlaws, wear mechanism and lubrication performance of materials and lubricants, which aims to provideguidance and reference for future theoretical investigations on revealing the essence of friction, wear andlubrication. MD simulation researches upon the tribology, tribochemistry and lubrication are summarized,focusing on the field of friction and wear mechanism, nano-tribology, liquid lubricants, lubricant additives,superlubricity phenomenon, etc. Besides, the challenges and problems remain to be considered, as well asfuture development directions of MD simulation are briefly discussed.With the help of MD method, the obstacleto tribology research caused by insufficient experimental methods can be reduced in the future.

Cascade Antidisturbance Control of Hydraulically Driven Bipedal Robots for High Dynamic Locomotion by Using Model Prediction and Task Hierarchical Optimization

Jie Huang,Huajie Hong,Nan Wang,Hongxu Ma,Honglei An,Lin Lang 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.4

The development of hydraulically driven heavy legs that can withstand external interference for realizing the high-velocity dynamic walking of bipedal robots with eight degrees-of-freedom is challenging. Therefore, in this study, a cascade antidisturbance algorithm was proposed for highly dynamic trajectory tracking based on model prediction and task hierarchical optimization. First, in the upper layer, the time-sharing control framework of underactuated robots based on the single rigid body model ignoring the legs was designed. Linear model predictive control (MPC) was designed to calculate the contact force spin to control the posture and height of floating base in the stand phase. The desired foot location principle was used to control the forward and lateral velocity in the swing phase. Next, in the lower layer, task hierarchical optimization control (THOC) was designed to track the contact force spin predicted by MPC. The relaxation variable of the force spin was designed in the optimized variable and subsequently used to compensate for the contact force between single rigid body and whole-body dynamic models. Thus, the tie relationship was developed between the upper MPC and lower THOC. The control robustness of the proposed model under high-velocity locomotion and disturbance was verified by performing simulation experiments investigating high-velocity walking and external impact, and the fast walking velocity was increased from 2.15 m/s of nonlinear MPC to 2.5 m/s with accurate velocity tracking.

Static and Seismic Experimental Study of Novel Prefabricated Beam-Column Joints with Elongated-Hole Brackets

Zhang Zhiwei,Li Dong,Wang Huajie,Li Songling,Qian Hongliang,Bi Yanhua,Wang Guoxing,Jin Xiaofei,Fan Feng 한국강구조학회 2024 International Journal of Steel Structures Vol.24 No.1

To enhance the structural connectivity of prefabricated steel frame systems and augment their construction effi ciency, this study introduces an innovative prefabricated joint design tailored for square steel columns and H-beams characterized by varying beam heights. This study includes both static loading tests and seismic tests performed on full-scale joints featuring two diff erent beam heights. This investigation involved a comprehensive analysis of the static and seismic performance of the joints, employing various performance metrics such as ultimate load capacities, ultimate rotation angles, hysteresis curves, skeleton curves, stiff ness degradation curves, and ductility coeffi cients, in alignment with established structural codes and standards. The results indicate that the plasticity of the H-beam is fully developed, exhibiting a relative slip phenomenon. Additionally, the joints demonstrate commendable rotational capacity, with hysteresis curves consistently manifesting an inverse S-shape and exhibiting noteworthy stiff ness degradation. Furthermore, the comparison with the unimproved joint shows that the novel joint, in addition to being easy to construct, has better ductility and energy dissipation capacity. The results of the study will provide a technical reference for further optimization and application of prefabricated beam-column joints.