Lowest Instrumented Vertebra at L3 Versus L4 in Posterior Fusion for Moderate Lenke 5C Type Adolescent Idiopathic Scoliosis: A Case-Match Radiological Study

Zhiyi Li,You Du,Yiwei Zhao,Guanfeng Lin,Haoran Zhang,Chenkai Li,Xiaohan Ye,Yang Yang,Shengru Wang,Jianguo Zhang 대한척추신경외과학회 2023 Neurospine Vol.20 No.4

Objective: To compare the radiological outcomes in Lenke 5C type patients whose lowest instrumented vertebra (LIV) was L3 or L4 in a case-match study. Methods: We conducted a retrospective case-match study and included 82 patients in the study. Radiological results before surgery, after surgery, and at last follow-up were recorded and analyzed in the L3 and L4 groups. Results: After matching the age, Risser’s sign, sex, and main Cobb, 41 pairs of patients were enrolled in our study. The total fusion segments in the L3 group (median [interquartile range]: 5.0 [6.0–5.0]) were shorter than those in the L4 group (6.0 [6.5–6.0]). The main curve was significantly corrected after surgery in both groups, and was comparable at the last followup between groups. In addition, according to the results of Fisher precision probability test, there was no significant difference of coronal or sagittal imbalance between the 2 groups at the 2-year follow-up. Conclusion: The correction in coronal and sagittal planes in L3 group and L4 group remains similar. On account of more motion segments, L3 could be an ideal choice as LIV in moderate Lenke 5C type AIS. Long-term follow-up is needed to evaluate the effect of larger compensatory lumbar-sacral curve when stopping at L3.

Potential molecular mechanisms underlying the effect of arsenic on angiogenesis

Juan Zhang,Yue Zhang,Weiyan Wang,Zhiyi Zhang 대한약학회 2019 Archives of Pharmacal Research Vol.42 No.11

Arsenic is a potent chemotherapeutic drug thatis applied as a treatment for cancer; it exerts its functionsthrough multiple pathways, including angiogenesis inhibition. As angiogenesis is a critical component of the progressionof many diseases, arsenic is a feasible treatmentoption for patients with other angiogenic diseases, includingrheumatoid arthritis and psoriasis, among others. However,arsenic is also a well-known carcinogen, demonstrating apro-angiogenesis effect. This review will focus on the dualeffects of arsenic on neovascularization and the relevantmechanisms underlying these effects, aiming to provide arational understanding of arsenic treatment. In particular, weexpect to provide a comprehensive overview of the currentknowledge of the mechanisms by which arsenic influencesangiogenesis.

Comparison of Deformation Behavior of Saturated Sand under Constant and Variable Deviatoric Stress

Zhiyi Zhao,Gang Deng,Yunshan Han,Zhaopeng Zhang,Yanli Dong,Ying Gao 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.3

The cyclic triaxial tests were carried out on Fujian standard sand under two stress paths, the constant deviatoric stress path (CDS) and constant stress-ratio path (variable deviatoric stress, VDS), and the influence of cyclic deviatoric stress on the development characteristics of saturated sand was preliminarily discussed. Under the condition of the same consolidation stress state and amplitude of cyclic spherical stress, the amplitude of deviatoric stress under the two stress paths was different. The test results indicated that cyclic deviatoric stress had significant effect on the volumetric and shear strain in soil. When the consolidation deviatoric stress was relatively small, the volumetric and shear strain curves under these two stress paths almost coincided. However, the cyclic deviatoric stress had a stronger effect with an increase in the consolidation deviatoric stress. During the loading and unloading stages, the slope of the volumetric strain curve under the VDS path was smaller than that under the CDS path. The accumulated volumetric strain under the VDS path was greater than that under the CDS path. In the loading stage, the growth rate of shear strain under the VDS path was greater than that under the CDS path, but the opposite relationship was observed in the unloading stage. The presence of cyclic deviatoric stress accelerated or slowed down the accumulation of shear strain. These phenomena were related to the positional relationship between the stress state of soil and the critical state line.

The Research and Application of Multiple Spindle Dynamic Follow to Improve CNC Thread Milling Products Precision

Peng Xiao,Zhiyi Zhang,Wengang Zheng 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.8

In this paper, a new control method is proposed. The SIEMENS 828D control system reads a feed axis machining of any one time processing, calculates the axis displacement data and draws the other two related linkage axis machining data. it through the PLC program of the control system written way R parameter is assigned to the other two related linkage of shaft processing program. Dynamic following effect of forming milling thread machining, reduce the product processing error, improve the product processing precision, technical indicators satisfy the similar foreign products.

An experiment investigation on the effect of Coulomb friction on the displacement transmissibility of a quasi-zero stiffness isolator

Xingtian Liu,Qiang Zhao,ZhiYi Zhang,Xubin Zhou 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

The effect of the Coulomb friction on a quasi-zero stiffness (QZS) isolator which configured by combining an Euler buckled beam negative stiffness corrector and a linear isolator is presented in this paper. Assuming friction damping provided by linear roller guider, the dynamic responses of the vibration isolation system and the equivalent linear one are obtained by using harmonic balance method (HBM). The static and dynamic characteristics of the QZS isolator are both investigated. For the linear isolator, the resonance frequency will increase and the peak transmissibility will decrease with the increasing of Coulomb friction or the decreasing of the excitation amplitude. However, in the case of QZS isolator, the natural frequency is decreased with the help of the negative stiffness mechanism and the amplification factor at the resonance is not obvious with the presence of the friction damping. Theory and experiment show good accordance. Therefore, it is recommend that one should add light Coulomb friction damping into the system to get better performance when using the QZS isolator in practice. The results present here can be a useful guideline when design such kind of vibration isolator.

Transverse impact characteristics of a rubber pipe expansion joint

Yong Chen,Wang Yu,ZhiYi Zhang,Hongxing Hua 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.6

The transverse impact characteristics of a rubber pipe expansion joint are studied. A pair of joints assembled end to end with an inserted middle mass is tested on a drop shock testing machine. Based on the test results, an equivalent fixed-fixed beam model with polynomial stiffness and damping is applied to predict the transverse impact response and identify the nonlinear impact parameters. The least square residual between the computed and test results is defined to drive the identification optimization. The response surface methodology in combination with the generalized reduced gradient method is used to search the best matching coefficients. Final results show that the equivalent bending stiffness of the tested rubber expansion joint gradually decreases with the transverse deformation and is greatly influenced by its internal working pressure.

Optimization Design of an Ultra-Low Specific-Speed Centrifugal Pump Using Entropy Production Minimization and Taguchi Method

Cong Wang,Yongxue Zhang,Hucan Hou,Zhiyi Yuan,Ming Liu 한국유체기계학회 2020 International journal of fluid machinery and syste Vol.13 No.1

To improve the energy conversion efficiency and cavitation performance of the ultra-low specific-speed centrifugal pump (ULSSCP), the impeller-volute interaction has been studied. Blade outlet setting angle (β₂), wrap angle (φ), volute inlet width (b₃) and throat area (St) were addressed as the design parameters. The entropy production at 0.5 Q0 and NPSHc (critical net positive suction head) at 1.5 Q0 were selected as the target to characterize the energy loss and cavitation performance. The L9 (3⁴) orthogonal matrix was established via Taguchi method. Results show that the contribution ratio of φ on S/NS is the most vital, followed by b₃ and St, while the influence of β₂ is relatively small, and the design parameter combination with β₂=19°, φ=220°, b₃=12mm and St=190㎟ is the best choice for the lowest entropy production at 0.5Q0 and NPSHc. At last, the optimization design reduces the loss greatly before and after cavitation by alleviation of vortex generation and backflow intensity.

Ginsenosides as dietary supplements with immunomodulatory effects: a review

Tang Ping,Liu Sitong,Zhang Junshun,Ai Zhiyi,Hu Yue,Cui Linlin,Zou Hongyang,Li Xia,Wang Yu,Nan Bo,Wang Yuhua 한국응용생명화학회 2024 Applied Biological Chemistry (Appl Biol Chem) Vol.67 No.-

Immune disorders have become one of the public health problems and imposes a serious economic and social burden worldwide. Ginsenosides, the main active constituents of ginseng, are regarded as a novel supplementary strategy for preventing and improving immune disorders and related diseases. This review summarized the recent research progress of ginsenosides in immunomodulation and proposed future directions to promote the development and application of ginsenosides. After critically reviewing the immunomodulatory potential of ginsenosides both in vitro and in vivo and even in clinical data of humans, we provided a perspective that ginsenosides regulated the immune system through activation of immune cells, cytokines, and signaling pathways such as MAPK, PI3K/ Akt, STAT, and AMPK, as well as positively affected immune organs, gut flora structure, and systemic inflammatory responses. However, the evidence for the safety and efficacy of ginsenosides is insufficient, and the immune pathways of ginsenosides remain incompletely characterized. We believe that this review will provide a valuable reference for further research on ginsenosides as dietary supplements with immunomodulatory effects.

Identification of floral aromatic volatile compounds in 29 cultivars from four groups of Osmanthus fragrans by gas chromatography–mass spectrometry

Jianxin Fu,Dan Hou,Yiguang Wang,Chao Zhang,Zhiyi Bao,Hongbo Zhao,Shaoqing Hu 한국원예학회 2019 Horticulture, Environment, and Biotechnology Vol.60 No.4

Osmanthus fragrans Lour. is a popular aromatic ornamental plant and its fl owers are used to enhance the color and fragrance of food. In this study, we analyzed the volatiles of 29 cultivars from all four groups of O. fragrans using a solid-phase microextraction (SPME) technique and gas chromatography–mass spectrometry (GC–MS). We identifi ed 41 volatile organic components that were distributed over fi ve diff erent compound classes, with the majority of the volatile components being dominated by alcohols, ketones, and terpenes, which accounted for 56.6–95.06% of the total volatiles in all tested materials except ‘Zao Yingui’. In ‘Zao Yingui’, alcohols, ketones, and terpenes accounted for only 48.19% of the total volatiles. The diversity of the volatile compounds and their relative contents varied among the four groups and cultivars within each group. The major volatile compounds were α-ionone, β-ionone, 2H-β-ionone, linalool, trans -linalool oxide, cis -linalool oxide, epoxy linalool, geraniol ( Z )-ocimene, and γ-decalactone in all tested cultivars, while nerol and ( Z )-3-hexenyl butanoic acid ester were abundant in several cultivars. The 29 cultivars were classifi ed into fi ve clusters in a hierarchical cluster analysis based on their fl oral volatile compounds. The cultivars of diff erent sexes (male vs. hermaphrodite) had no signifi cant diff erences in the relative contents of the major volatile compounds. This study provides valuable information for understanding the chemical composition of the volatile compounds of O. fragrans fl owers as well as a theoretical basis for the origin, development, and application of modern cultivars of O. fragrans.

Design and Analysis of a Parallel Hybrid Memory Architecture for Per-Flow Buffering in High-Speed Switches and Routers

Ling Zheng,Zhiliang Qiu,Shiyong Sun,Weitao Pan,Ya Gao,Zhiyi Zhang 한국통신학회 2018 Journal of communications and networks Vol.20 No.6

The network switches and routers require both highspeedand large-capacity packet buffers. However, existing packetbuffer architectures have the problems of speed scaling and flownumber scaling limitations. To address the two problems simultaneously,this paper proposes a parallel hybrid SRAM/DRAMarchitecture for per-flow buffering in high-speed switches androuters. Tail SRAM and head SRAM are used to apply per-flowbuffering for packet aggregation, so that the middle DRAM is accessedin a larger granularity and the DRAM’s bandwidth utilizationis improved. To mitigate the flow number scaling limitation,a dynamic memory allocation with hard timeout (DMA-HT) memorymanagement algorithm is designed. The key idea of DMA-HTis that the memory space is dynamically allocated for the newly arrivedflows, and a hard timeout is assigned for each queue. Aftera specific period of time, the memory space is freed, so that theSRAM space is efficiently utilized by the most recently active flows. A queuing system is used to model the proposed method, and theoreticalanalysis is performed to optimize the timeout value. Withthe derived formulas, multiple performance parameters are quantitativelyanalyzed, and the optimal timeout can be obtained. Bothnumerical results and simulations show that the proposed architecturecan and reduce packet loss rate and average delay significantlycompared with previous solutions with the same SRAM capacity.