Biomechanical Evaluation of 2 Endoscopic Spine Surgery Methods for Treating Lumbar Disc Herniation: A Finite Element Study

Yang Zou,Shuo Ji,Hui Wen Yang,Tao Ma,Yue Kun Fang,Zhi Cheng Wang,Miao Miao Liu,Ping Hui Zhou,Zheng Qi Bao,Chang Chun Zhang,Yu Chen Ye 대한척추신경외과학회 2024 Neurospine Vol.21 No.1

Objective: This study aimed to evaluate the effects of 2 endoscopic spine surgeries on the biomechanical properties of normal and osteoporotic spines. Methods: Based on computed tomography images of a healthy adult volunteer, 6 finite element models were created. After validating the normal intact model, a concentrated force of 400 N and a moment of 7.5 Nm were exerted on the upper surface of L3 to simulate 6 physiological activities of the spine. Five types of indices were used to assess the biomechanical properties of the 6 models, range of motion (ROM), maximum displacement value, intervertebral disc stress, maximum stress value, and articular protrusion stress, and by combining them with finite element stress cloud. Results: In normal and osteoporotic spines, there was no meaningful change in ROM or disc stress in the 2 surgical models for the 6 motion states. Model N1 (osteoporotic percutaneous transforaminal endoscopic discectomy model) showed a decrease in maximum displacement value of 20.28% in right lateral bending. Model M2 (unilateral biportal endoscopic model) increased maximum displacement values of 16.88% and 17.82% during left and right lateral bending, respectively. The maximum stress value of L4–5 increased by 11.72% for model M2 during left rotation. In addition, using the same surgical approach, ROM, maximum displacement values, disc stress, and maximum stress values were more significant in the osteoporotic model than in the normal model. Conclusion: In both normal and osteoporotic spines, both surgical approaches were less disruptive to the physiologic structure of the spine. Furthermore, using the same endoscopic spine surgery, normal spine biomechanical properties are superior to osteoporotic spines.

The changes in the proteolysis activity and the accumulation of free amino acids during chinese traditional dry-cured loins processing

Chang-Yu Zhou,Ying Wang,Dao-Dong Pan,Jin-Xuan Cao,Yin-Ji Chen,Yuan Liu,Yang-Ying Sun,Chang-Rong Ou 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.3

Twelve pieces of longissimus dorsi were processed into Chinese traditional dry-cured loins. The changes in the proteolylic enzymes activities, myofibrillar proteins degradation, and free amino acids content were investigated during processing. Compared with fresh piece (0 day), the cathepsin B ? L and calpains activities decreased after dry-curing and maintained potential activities values of 23.25 and 15.04% in the final products, respectively. The myosin heavy chain (MHC) and C protein were intensely degraded at the dry-ripened stage; the 50 kDa desmin increased at day 2 and then disappeared at day 11. The total free amino acids content increased from 333.18 mg/100 g in the raw to 1096.54 mg/100 g at the end of the dry-ripening. This work provided a mechanism for the accumulation of free amino acids and predicted the proteolysis extent of myofibrillar proteins by monitoring the changes of three marker proteins (MHC, C protein and 50 kDa desmin) during Chinese traditional dry-cured loins processing. Keywords

Transient Characteristics and Physical Constraints of Grid-Tied Virtual Synchronous Machines

Chang Yuan,Chang Liu,Dan Yang,Ruibing Zhou,Niang Tang 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.4

In modern power systems, distributed generators (DGs) result in high stress on system frequency stability. Apart from the intermittent nature of DGs, most DGs do not contribute inertia or damping to systems. As a result, a new control method referred to as a virtual synchronous machine (VSM) has been proposed, which brought new characteristics to inverters such as synchronous machines (SM). DGs employing an energy storage system (ESS) provide inertia and damping through VSM control. Meanwhile, energy storage presents some physical constraints in the VSM implementation level. In this paper, a VSM mathematical model is built and analyzed. The dynamic responses of the output active power are presented when a step change in the frequency occurs. The influences of the inertia constant, damping factor and operating point on the ESS volume margins are investigated. In addition, physical constraints are proposed based on these analyses. The proposed physical constraints are simulated using PSCAD/EMTDC software and tested through RTDS experiment. Both simulation and RTDS test results verify the analysis.

Transient Characteristics and Physical Constraints of Grid-Tied Virtual Synchronous Machines

Yuan, Chang,Liu, Chang,Yang, Dan,Zhou, Ruibing,Tang, Niang The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.4

In modern power systems, distributed generators (DGs) result in high stress on system frequency stability. Apart from the intermittent nature of DGs, most DGs do not contribute inertia or damping to systems. As a result, a new control method referred to as a virtual synchronous machine (VSM) has been proposed, which brought new characteristics to inverters such as synchronous machines (SM). DGs employing an energy storage system (ESS) provide inertia and damping through VSM control. Meanwhile, energy storage presents some physical constraints in the VSM implementation level. In this paper, a VSM mathematical model is built and analyzed. The dynamic responses of the output active power are presented when a step change in the frequency occurs. The influences of the inertia constant, damping factor and operating point on the ESS volume margins are investigated. In addition, physical constraints are proposed based on these analyses. The proposed physical constraints are simulated using PSCAD/EMTDC software and tested through RTDS experiment. Both simulation and RTDS test results verify the analysis.

Detection of rare point mutation via allele-specific amplification in emulsion PCR

Chang Ming Cheng,Yin Zhou,Chao Yang,Juan Chen,Jie Wang,Jie Zhang,Guo Ping Zhao 생화학분자생물학회(구 한국생화학분자생물학회) 2013 BMB Reports Vol.46 No.5

Construction of a Protein-Protein Interaction Network for Chronic Myelocytic Leukemia and Pathway Prediction of Molecular Complexes

Zhou, Chao,Teng, Wen-Jing,Yang, Jing,Hu, Zhen-Bo,Wang, Cong-Cong,Qin, Bao-Ning,Lv, Qing-Liang,Liu, Ze-Wang,Sun, Chang-Gang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Background: Chronic myelocytic leukemia is a disease that threatens both adults and children. Great progress has been achieved in treatment but protein-protein interaction networks underlining chronic myelocytic leukemia are less known. Objective: To develop a protein-protein interaction network for chronic myelocytic leukemia based on gene expression and to predict biological pathways underlying molecular complexes in the network. Materials and Methods: Genes involved in chronic myelocytic leukemia were selected from OMIM database. Literature mining was performed by Agilent Literature Search plugin and a protein-protein interaction network of chronic myelocytic leukemia was established by Cytoscape. The molecular complexes in the network were detected by Clusterviz plugin and pathway enrichment of molecular complexes were performed by DAVID online. Results and Discussion: There are seventy-nine chronic myelocytic leukemia genes in the Mendelian Inheritance In Man Database. The protein-protein interaction network of chronic myelocytic leukemia contained 638 nodes, 1830 edges and perhaps 5 molecular complexes. Among them, complex 1 is involved in pathways that are related to cytokine secretion, cytokine-receptor binding, cytokine receptor signaling, while complex 3 is related to biological behavior of tumors which can provide the bioinformatic foundation for further understanding the mechanisms of chronic myelocytic leukemia.

REVIEW : Modifiers of TGF-b1 effector function as novel therapeutic targets of pulmonary fibrosis

( Chang Min Lee ),( Jin Wook Park ),( Won Kyung Cho ),( Yang Zhou ),( Bo Ram Han ),( Pyoung Oh Yoon ),( Jei Wook Chae ),( Jack A Elias ),( And Chun Geun Lee ) 대한내과학회 2014 The Korean Journal of Internal Medicine Vol.29 No.3

Pulmonary fibrosis is a fatal progressive disease with no effective therapy. Transforminggrowth factor (TGF)-b1 has long been regarded as a central mediator oftissue fibrosis that involves multiple organs including skin, liver, kidney, and lung. Thus, TGF-b1 and its signaling pathways have been attractive therapeutic targetsfor the development of antifibrotic drugs. However, the essential biological functionsof TGF-b1 in maintaining normal immune and cellular homeostasis significantlylimit the effectiveness of TGF-b1-directed therapeutic approaches. Thus,targeting downstream mediators or signaling molecules of TGF-b1 could be an alternativeapproach that selectively inhibits TGF-b1-stimulated fibrotic tissue responsewhile preserving major physiological function of TGF-b1. Recent studiesfrom our laboratory revealed that TGF-b1 crosstalk with epidermal growth factorreceptor (EGFR) signaling by induction of amphiregulin, a ligand of EGFR, plays acritical role in the development or progression of pulmonary fibrosis. In addition,chitotriosidase, a true chitinase in humans, has been identified to have modulatingcapacity of TGF-b1 signaling as a new biomarker and therapeutic target of scleroderma-associated pulmonary fibrosis. These newly identified modifiers of TGF-b1effector function significantly enhance the effectiveness and flexibility in targetingpulmonary fibrosis in which TGF-b1 plays a significant role.

Facile Fabrication of Superhydrophobic Cellulose/Fe2O3-STA Film with Nanoflower Morphologies for Heavy Oil Removal

Chang-Lian Xu,Shiyi Wang,Lu Zhou,Yiwen Bi,Gang Yang,Jun Wu,Xiaohong Zhang 한국섬유공학회 2022 Fibers and polymers Vol.23 No.10

Heavy oils induced water pollutions are difficult to be eliminated due to the oils located under water. Herein, wefabricated superhydrophobic cellulose film with nanoflower structures via a Facile method to eliminate heavy oil from water. Cellulose films were in-situ modified with Fe2O3 and stearic acid (STA) for superhydrophobic modification. Thecorresponding superhydrophobic cellulose/Fe2O3-STA film has water contact angle of 155.5 º and sliding angle of 5.5 º, andcan maintains its superhydrophobicity when it is immersed in water. The film exists excellent self-cleaning property, and thedusts on the film could be easily swept away by running water drops. The film was further applied to separate heavy oil/watermixture with separation efficiency of 99.37 %, and the separation efficiency was maintained after 20 separation cycles aswell. The film can also be utilized to absorb small heavy oil drops under water. Thus, we not only develop a simple way toproduce superhydrophobic cellulose based films, but also provide superhydrophobic materials to solve water pollutioncaused by heavy oil.

Effects of the Hippo Signaling Pathway in Human Gastric Cancer

Zhou, Guang-Xi,Li, Xiao-Yu,Zhang, Qi,Zhao, Kun,Zhang, Cui-Ping,Xue, Chang-Hu,Yang, Kun,Tian, Zi-Bin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.9

Background/Aim: The Hippo signaling pathway is a newly discovered and conserved signaling cascade, which regulates organ size control by governing cell proliferation and apoptosis. This study aimed to investigate its effects in human gastric cancer. Methods: Tumor tissues (n=60), adjacent non-tumor tissues (n=60) and normal tissues (n=60) were obtained from the same patients with primary gastric cancer (GC). In addition, 70 samples of chronic atrophic gastritis (CAG) tissues were obtained from patients with intestinal metaplasia (IM) by endoscopic biopsy. Hippo signaling molecules, including Mst1, Lats1, YAP1, TAZ, TEAD1, Oct4 and CDX2, were determined by quantitative polymerase chain reaction (qPCR). Protein expression of Mst1, Lats1, YAP1, TEAD1 and CDX2 was assessed by immunohistochemistry and Western blotting. Results: Mst1, Lats1 and Oct4 mRNA expression showed an increasing tendency from GC tissues to normal gastric tissues, while the mRNA expression of YAP1, TAZ and TEAD1 was up-regulated (all P<0.01). Mst1 and Lats1 protein expression presented a similar trend with their mRNA expression. In addition, YAP1 and TEAD1 protein expression in GC was significantly higher than in the other groups (all P<0.01). CDX2 mRNA and protein expression in the CAG group were higher than in the other groups (all P<0.01). In GC, mRNA expression of Mst1, Lats1, Oct4, YAP1, TAZ, TEAD1 and CDX2 had a close correlation with lymphatic metastasis and tumor TNM stage (all P<0.01). Furthermore, protein expression of Mst1, Lats1, YAP1, TAZ, TEAD1 and CDX2 had a close correlation between each other (P<0.05). Conclusion: The Hippo signaling pathway is involved in the development, progression and metastasis of human gastric cancer. Therefore, manipulation of Hippo signaling molecules may be a potential therapeutic strategy for gastric cancer.

Evaluation of different media for ex vivo porcine lung culture model

Yang, Myeon-Sik,Zhou, Zixiong,Khatun, Amina,Nazki, Salik,Jeong, Chang Gi,Kim, Won Il,Lee, Sang Myeong,Kang, Seog-Jin,Lim, Chae Woong,Kim, Bumseok The Korean Society of Veterinary Service 2018 韓國家畜衛生學會誌 Vol.41 No.4

Developing drugs targeting respiratory pathogen is essential to control respiratory diseases. Many experiments have been performed under in vivo situation. However, in vivo experiments have economical and ethical issues. The objective of this study was to determine the possibility of developing an ex vivo lung culture system with possible application for respiratory infection studies. After isolating lungs from naïve pigs, agarose-inflated lung tissues were prepared and sliced manually. These sliced lung tissues were then subsequently placed on 24-well plates. Eight different combinations of media were used to determine the optimum ex vivo lung culture condition. In addition, lung tissues were infected with porcine reproductive and respiratory syndrome (PRRS) virus at a titer of $1{\times}10^4\;TCID_{50}/mL$. Virus growth was confirmed by titration in MARC-145 cells at 2, 4, 6 days post infection (dpi). We found that ex vivo lung culture in physiological environment was not media specific based on histopathology and cytotoxicity. However, under virus-infected condition, thickened alveolar walls in the lung tissues and stable virus titers at 2, 4, 6 dpi were shown in F12K medium suggesting that it was useful for tissue maintenance and virus infection using PRRS virus infected lung tissues. The present study shows the possibility of using porcine ex vivo lung model for respiratory infection studies.