Vibration Characteristics of Cutter-Head in Soft-Hard Mixed Stratum: An Experimental Case Study on Su’ai Tunnel

Zhenxing Yang,Dongjiang Pan,Jianjun Zhou,Jian Chen,Zhenchuan Sun,Haining Liu 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.4

This paper conducts a simulation experiment research on cutter-head vibration characteristics by evaluating a soft-hard mixed stratum (the upper layer is silty soil, whereas the lower layer is moderately weathered granite of maximum uniaxial compressive strength (UCS) 142.0 MPa and slightly weathered granite of maximum 210.0 MPa). The ratios of hard rock and soil within the tunnel face were designed to be 1:1 and 1:2. Then, the cutter-head and stratum model were subjected to vibration analysis by reasonably deployed accelerometers. Results show that: 1) different conditions of heterogeneous strata mainly affected the acceleration amplitude and frequency distribution of cutter-head, in other words, the stronger hard rock, the larger the strength difference between the hard rock and soil within a tunnel face, the larger the vibration acceleration and the more concentrated the vibration frequency distribution; 2) the radial and circumferential vibration acceleration of the cutter-head in different positions were not largely different; however, axial accelerations were largely different. The axial vibration accelerations first increased and then decreased along the radial direction of cutter-head. Considering the difference between Multi-Mode Boring Test System and real cutter-head structure, the radius of joint between the cutter-head and the flange plate should be reasonably increased according to the ratio of hard rock in tunnel face; 3) with the increasing difference between the strength of the hard rock and soil, the circumferential and axial vibration acceleration multiplied. Thus, the soil remarkably reduces the vibration of the cutter-head. These results can provide some evidence of potential application for advancing manufacturing practice for cutter-head and disc cutter of shield machine.

Pressure-Induced Confined Metal from the Mott InsulatorSr3Ir2O7

Ding, Yang,Yang, Liuxiang,Chen, Cheng-Chien,Kim, Heung-Sik,Han, Myung Joon,Luo, Wei,Feng, Zhenxing,Upton, Mary,Casa, Diego,Kim, Jungho,Gog, Thomas,Zeng, Zhidan,Cao, Gang,Mao, Ho-kwang,van Veenendaal, American Physical Society 2016 Physical Review Letters Vol.116 No.21

<P>The spin-orbit Mott insulator Sr3Ir2O7 provides a fascinating playground to explore insulator-metal transition driven by intertwined charge, spin, and lattice degrees of freedom. Here, we report high-pressure electric resistance and resonant inelastic x-ray scattering measurements on single-crystal Sr3Ir2O7 up to 63-65 GPa at 300 K. The material becomes a confined metal at 59.5 GPa, showing metallicity in the ab plane but an insulating behavior along the c axis. Such an unusual phenomenon resembles the strange metal phase in cuprate superconductors. Since there is no sign of the collapse of spin-orbit or Coulomb interactions in x-ray measurements, this novel insulator-metal transition is potentially driven by a first-order structural change at nearby pressures. Our discovery points to a new approach for synthesizing functional materials.</P>

Transfer properties of Gorenstein homological dimension with respect to a semidualizing module

Zhenxing Di,Xiaoyan Yang 대한수학회 2012 대한수학회지 Vol.49 No.6

The classes of GC homological modules over commutative ring, where C is a semidualizing module, extend Holm and Jgensen's notions of C-Gorenstein homological modules to the non-Noetherian set-ting and generalize the classical classes of homological modules and the classes of Gorenstein homological modules within this setting. On the other hand, transfer of homological properties along ring homomorphisms is already a classical eld of study. Motivated by the ideas mentioned above, in this article we will investigate the transfer properties of C and GC homological dimension.

TRANSFER PROPERTIES OF GORENSTEIN HOMOLOGICAL DIMENSION WITH RESPECT TO A SEMIDUALIZING MODULE

Di, Zhenxing,Yang, Xiaoyan Korean Mathematical Society 2012 대한수학회지 Vol.49 No.6

The classes of $G_C$ homological modules over commutative ring, where C is a semidualizing module, extend Holm and J${\varnothing}$gensen's notions of C-Gorenstein homological modules to the non-Noetherian setting and generalize the classical classes of homological modules and the classes of Gorenstein homological modules within this setting. On the other hand, transfer of homological properties along ring homomorphisms is already a classical field of study. Motivated by the ideas mentioned above, in this article we will investigate the transfer properties of C and $G_C$ homological dimension.

A GPC-based Multi-variable PID Control Algorithm and Its Application in Anti-swing Control and Accurate Positioning Control for Bridge Cranes

Bin Yang,Zhenxing Liu,Hui-Kang Liu,Yan Li,Sen Lin 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.10

It is one of the key tasks for the bridge crane to achieve anti-swing control of the hook and the accurate positioning of the body to work efficiently, safely and automatically. Based on the Lagrange equation, this paper is to propose a dynamic model of the crane motion system for designing controller. In the controller design, ProportionalIntegral-Derivative (PID), the most widely used controller in engineering, is adopted and a new parameter tuning algorithm for a multi-variable PID controller based on generalized predictive control (GPC) is given. It is foundthat the multi-variable PID controller shares the same structural mathematical expressions with the GPC law, which makes for the transfer and calculation of the three parameters P, I and D, and that the new algorithm enables the traditional PID controller to perform as brilliantly as the GPC. The results of both the simulation and real-time control experiments show that the newly-proposed PID controller can effectively eliminate the swing of the hook and control the bridge cranes moving position accurately.

Differential Effects of Lactobacillus casei Strain Shirota on Patients With Constipation Regarding Stool Consistency in China

Shanbin Chen,Yangwenshan Ou,Liang Zhao,Yang Li,Zhenxing Qiao,Yanling Hao,Fazheng Ren 대한소화기 기능성질환∙운동학회 2019 Journal of Neurogastroenterology and Motility (JNM Vol.25 No.1

Background/Aims Probiotics are expected to confer benefits on patients with constipation, but how probiotics act on constipated patients with variable stool consistencies remains unclear. We investigated the effect of Lactobacillus casei strain Shirota (LcS) on constipation-related symptoms, especially stool consistency, of constipated patients. Methods Constipated patients meeting the Rome III criteria were divided into 3 groups according to the Bristol Stool Form Scale (BSFS): hard (hard stool [HS], BSFS < 3), normal (normal stool [NS], ≤ 3 BSFS ≤ 4), and soft (soft stool [SS], 4 < BSFS ≤ 5) stools. Subjects in each group consumed a probiotic beverage containing 1010 colony-forming units of LcS daily for 28 days. Results LcS intervention significantly alleviated constipation-related symptoms and increased defecation frequency in all subjects. Four weeks of LcS supplementation softened the hard stools in HS, hardened the soft stools in SS, and did not alter the ideal stool consistency in NS. The short-chain fatty acid (SCFA) concentrations were highest in SS, followed by NS and HS. LcS intervention increased the stool SCFA levels in HS but reduced or did not alter the levels in NS and SS. LcS intervention increased the Pseudobutyrivibrio and Roseburia abundances in HS and decreased the Pseudobutyrivibrio abundance in SS. Conclusions LcS supplementation improved the constipation-related symptoms in constipated subjects. Differences in baseline stool consistency could result in different anti-constipation effects of LcS intervention. LcS balanced the stool consistency—softened the HS and hardened the SS. These effects could be associated with modulation of the gut microbiota and SCFA production.

Impaired Na+ −K+-ATPase signaling in renal proximal tubule contributes to hyperuricemia-induced renal tubular injury

Jing Xiao,Xiaoli Zhang,Chensheng Fu,Qingmei Yang,Ying Xie,Zhenxing Zhang,Zhibin Ye 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Hyperuricemia contributes to renal inflammation. We aimed to investigate the role of Na+–K+–ATPase (NKA) in hyperuricemiainduced renal tubular injury. Human primary proximal tubular epithelial cells (PTECs) were incubated with uric acid (UA) at increasing doses or for increasing lengths of time. PTECs were then stimulated by pre-incubation with an NKA α1 expression vector or small interfering RNA before UA (100 μg ml−1, 48 h) stimulation. Hyperuricemic rats were induced by gastric oxonic acid and treated with febuxostat (Feb). ATP levels, the activity of NKA and expression of its α1 subunit, Src, NOD-like receptor pyrin domain-containing protein 3 (NLRP3) and interleukin 1β (IL-1β) were measured both in vitro and in vivo. Beginning at concentrations of 100 μg ml−1, UA started to dose-dependently reduce NKA activity. UA at a concentration of 100 μg ml−1 time-dependently affected the NKA activity, with the maximal increased NKA activity at 24 h, but the activity started to decrease after 48 h. This inhibitory effect of UA on NKA activity at 48 h was in addition to a decrease in NKA α1 expression in the cell membrane, but an increase in lysosomes. This process also involved the subsequent activation of Src kinase and NLRP3, promoting IL-1β processing. In hyperuricemic rats, renal cortex NKA activity and its α1 expression were upregulated at the 7th week and both decreased at the 10th week, accompanied with increased renal cortex expression of Src, NLRP3 and IL-1β. The UA levels were reduced and renal tubular injuries in hyperuricemic rats were alleviated in the Feb group. Our data suggested that the impairment of NKA and its consequent regulation of Src, NLRP3 and IL-1β in the renal proximal tubule contributed to hyperuricemia-induced renal tubular injury.

ZNF435, a Novel Human SCAN-containing Zinc Finger Protein, Inhibits AP-1-mediated Transcriptional Activation

Xing Gu,Mei Zheng,Xiangwei Fei,Zhenxing Yang,Fan Li,Chaoneng Ji,Yi Xie,Yumin Mao 한국분자세포생물학회 2007 Molecules and cells Vol.23 No.3

High yield engineered nanovesicles from ADSC with enriched miR-21-5p promote angiogenesis in adipose tissue regeneration

Sun Di,Mou Shan,Chen Lifeng,Yang Jie,Wang Rongrong,Zhong Aimei,Wang Wei,Tong Jing,Wang Zhenxing,Sun Jiaming 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background: Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been found to have a great potential for soft tissue repair due to various biological functions, including pro-angiogenesis and low immunogenicity. However, the low yield and heterogeneity of MSC-EVs limited their clinical transformation. This study was designed to develop a novel adipose-derived stem cell engineered nanovesicles (ADSC-NVs) with high production and explore its pro-angiogenetic effect and application in adipose tissue regeneration. Methods: Adipose-derived stem cell-derived extracellular vesicles (ADSC-EVs) were isolated from an EVs-free culture medium for human ADSCs (hADSCs). ADSC-NVs were prepared by sequentially extruding ADSCs followed by iodixanol density gradient ultracentrifugation and were compared with ADSC-EVs in morphology, size distribution, protein contents and yield. The pro-angiogenetic effect of ADSC-NVs in different doses (0, 5, 20 and 80 μg/mL) in vitro was determined using transwell assay, tube formation assay, western blot and qRT-PCR. In vivo, BALB/c nude mice were administered injection of a mixture of fat granules and different dose of ADSC-NVs and grafts were harvested at 12 weeks post-transplantation for further analysis. By analyzing the weight and volume of grafts and histological evaluation, we investigated the effect of ADSC-NVs in vessel formation and adipose tissue regeneration. Results: Our results showed yield of purified ADSC-NVs was approximately 20 times more than that of ADSC-EVs secreted by the same number of ADSCs. In vitro, both ADSC-NVs and ADSC-EVs exhibited a dose-dependent proangiogenetic effect, despite their distinct miRNA profiles. These effects of ADSC-NVs may be mediated by enriched miR-21-5p via PTEN inhibition and PI3K/p-Akt signaling activation. Furthermore, after a mixed injection of ADSC-NVs, vessel formation and adipose regeneration were observed in vivo in fat implants. Conclusions: Our study developed a potent alternative of ADSC-EVs. ADSC-NVs have a high pro-angiogenesis potential and can be used as cell-free therapeutic biomaterials in soft tissue regeneration.

Increased Piezo1 channel activity in interstitial Cajal-like cells induces bladder hyperactivity by functionally interacting with NCX1 in rats with cyclophosphamide-induced cystitis

Qian Liu,Bishao Sun,Jiang Zhao,Qingqing Wang,Fan An,Xiaoyan Hu,Zhenxing Yang,Jie Xu,Mingjia Tan,Longkun Li 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

The Piezo1 channel is a mechanotransduction mediator, and Piezo1 abnormalities have been linked to several clinical disorders. However, the role of the Piezo1 channel in cystitis-associated bladder dysfunction has not been documented. The current study aimed to discover the functional role of this channel in regulating bladder activity during cyclophosphamide (CYP)-induced cystitis. One hundred four female rats were randomly assigned to the control, CYP-4h, CYP-48h and CYP-8d groups. CYP successfully induced acute or chronic cystitis in these rats. CYP treatment for 48h or 8d significantly increased Piezo1 channel expression in bladder interstitial Cajal-like cells (ICC-LCs), and the increase in CYP-8d rats was more prominent. In addition, 2.5 μM Grammostola spatulata mechanotoxin 4 (GsMTx4) significantly attenuated bladder hyperactivity in CYP-8d rats by inhibiting the Piezo1 channel in bladder ICCLCs. Furthermore, by using GsMTx4 and siRNA targeting the Piezo1 channel, we demonstrated that hypotonic stressinduced Piezo1 channel activation significantly triggered Ca2+ and Na+ influx into bladder ICC-LCs during CYPinduced chronic cystitis. In addition, the Piezo1 channel functionally interacted with the relatively activated reverse mode of Na+/Ca2+ exchanger 1 (NCX1) in bladder ICC-LCs from CYP-8d rats. In conclusion, we suggest that the functional role of the Piezo1 channel in CYP-induced chronic cystitis is based on its synergistic effects with NCX1, which can significantly enhance [Ca2+]i and result in Ca2+ overload in bladder ICC-LCs, indicating that the Piezo1 channel and NCX1 are potential novel therapeutic targets for chronic cystitis-associated bladder hyperactivity.