A Three-dimensional Biomechanical Model for Numerical Simulation of Dynamic Pressure Functional Performances of Graduated Compression Stocking (GCS)

Liu, Rong,Kwok, Yi-Lin,Li, Yi,Lao, Terence-T,Zhang, Xin,Dai, Xiao-Qun The Korean Fiber Society 2006 Fibers and polymers Vol.7 No.4

The beneficial effects of graduated compression stockings (GCS) in prophylaxis and treatment of venous disorders of human lower extremity have been recognized. However, their pressure functional performances are variable and unstable in practical applications, and the exact mechanisms of action remain controversial. Direct surface pressure measurements and indirect material properties testing are not enough for fully understanding the interaction between stocking and leg. A three dimensional (3D) biomechanical mathematical model for numerically simulating the interaction between leg and GCS in dynamic wear was developed based on the actual geometry of the female leg obtained from 3D reconstruction of MR images and the real size and mechanical properties of the compression stocking prototype. The biomechanical solid leg model consists of bones and soft tissues, and an orthotropic shell model is built for the stocking hose. The dynamic putting-on process is simulated by defining the contact of finite relative sliding between the two objects. The surface pressure magnitude and distribution along the different height levels of the leg and stress profiles of stockings were simulated. As well, their dynamic alterations with time processing were quantitatively analyzed. Through validation, the simulated results showed a reasonable agreement with the experimental measurements, and the simulated pressure gradient distribution from the ankle to the thigh (100:67:30) accorded with the advised criterion by the European committee for standardization. The developed model can be used to predict and visualize the dynamic pressure and stress performances exerted by compression stocking in wear, and to optimize the material mechanical properties in stocking design, thus, helping us understand mechanisms of compression action and improving medical functions of GCS.

The effects of paeoniflorin injection on soluble triggering receptor expressed on myeloid-1 (sTREM-1) levels in severe septic rats

Liu, Xiao-Rong,Xu, Jie,Wang, Yi-Min,Ji, Ming-Suo,Liu, Fu-Shan The Korean Society of Pharmacology 2016 The Korean Journal of Physiology & Pharmacology Vol.20 No.6

Paeoniflorin (PAE) is the most abundant compound in Xuebijing injection widely used to treat sepsis. We aimed to investigate effect of PAE on expression of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in a rat model of sepsis. Wistar rats were divided into Normal, Model, and PAE groups (n=20 each). Endotoxin was administrated at 5 mg/ml/kg in Model and PAE rats to establish rat sepsis model. 1 h after endotoxin administration, PAE was administrated at 4 ml/kg in PAE group once per day for 3 days. Routine blood tests and biochemical indexes were assessed, including aspartate aminotransferase (AST) and creatine kinase-MB (CK-MB). The plasma sTREM-1 level was measured using quantitative ELISA. At the end of experiment, the small intestine, liver, kidney and lung were subjected to pathological examinations. A rat model of sepsis-induced multiple organ dysfunction syndrome (MODS) was established successfully with endotoxin administration (5 mg/ml/kg), evidenced by histo-pathological examinations, routine blood tests and biochemical indexes: platelet count decreased and white blood cell count increased (p<0.05), CK-MB and AST increased (p<0.05). PAE treatment significantly reduced the plasma levels of AST, CK-MB, and sTREM-1, compared to Model group (p<0.05). Meanwhile, sepsis-induced damages in the liver, lung, stomach and intestinal mucosa were also markedly ameliorated by PAE treatment. PAE demonstrated a significantly protective effect in a rat model of sepsis by decreasing plasma sTREM-1 level, reducing inflammation, preventing MODS and protecting organ functions.

Numerical Simulation of Internal Stress Profiles and Three-dimensional Deformations of Lower Extremity Beneath Medical Graduated Compression Stocking (GCS)

Liu, Rong,Kwok, Yi-Lin,Li, Yi,Lao, Terence-T,Dai, Xiao Qun,Zhang, Xin The Korean Fiber Society 2007 Fibers and polymers Vol.8 No.3

The most significant medical function of graduated compression stocking (GCS) is to provide controlled support and pressure to the skin surface and the underlying tissues of the lower extremity, to prevent and treat venous disease, thus improving the blood circulation. However, due to lack of suitable technologies for the experimental measurements, the transfer mechanisms of the external pressure applied by GCS and internal stress states within the leg soft tissue were not well examined, which bring some difficulties to GCS compression design. The present study numerically simulated and analyzed surface pressure applied by GCS and the cross-sectional deformations at the target region of leg. The underlying tissues stress profiles as well as their dynamic alterations with time processing were presented and quantitatively investigated. Moreover, the medical significance of the cross-sectional inner stress distributions was discussed. The validation results indicated that the simulated pressure profiles applied by GCS agreed reasonably well with the measured ones. The developed biomechanical model can be used for prediction and analysis of the pressure functional performances applied by GCSs, thus helping us more understanding mechanisms of compression action and improving their medical functions.

Sustainable production of acrolein from biodiesel-derived crude glycerol over H3PW12O40 supported on Cs-modified SBA-15

Rong Liu,Shuting Lyu,Tiefeng Wang 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.37 No.-

The feasibility of producing acrolein from crude glycerol was studied by the dehydration reaction overH3PW12O40 (HPW) supported on Cs-modified SBA-15 (HPW/Cs-SBA). The influence of impurities incrude glycerol was investigated. Only the alkali metal ions caused catalyst deactivation and decreasedthe acrolein selectivity because they decreased the amount of catalytically effective medium Brønstedacid sites. This problem was solved by glycerol desalination, and a stable acrolein yield of 85% wasobtained through 60 h of reaction, which was as good as that with pure glycerol. In addition, HPW/Cs-SBA showed good thermal stability and regeneration ability after the reaction with desalted crudeglycerol.

Complex molecules in the W51 North region

Rong, J.,Qin, S.-L.,Zapata, L. A.,Wu, Y.,Liu, T.,Zhang, C.,Peng, Y.,Zhang, L.,Liu, Y. Oxford University Press 2016 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.455 No.2

Lack of Associations of the COMT Val158Met Polymorphism with Risk of Endometrial and Ovarian Cancer: a Pooled Analysis of Case-control Studies

Liu, Jin-Xin,Luo, Rong-Cheng,Li, Rong,Li, Xia,Guo, Yu-Wu,Ding, Da-Peng,Chen, Yi-Zhi Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

This meta-analysis was conducted to examine whether the genotype status of Val158Met polymorphism in catechol-O-methyltransferase (COMT) is associated with endometrial and ovarian cancer risk. Eligible studies were identified by searching several databases for relevant reports published before January 1, 2014. Pooled odds ratios (ORs) were appropriately derived from fixed-effects or random-effects models. In total, 15 studies (1,293 cases and 2,647 controls for ovarian cancer and 2,174 cases and 2,699 controls for endometrial cancer) were included in the present meta-analysis. When all studies were pooled into the meta-analysis, there was no evidence for significant association between COMT Val158Met polymorphism and ovarian cancer risk (Val/Met versus Val/Val: OR=0.91, 95% CI=0.76-1.08; Met/Met versus Val/Val: OR=0.90, 95% CI=0.73-1.10; dominant model: OR=0.90, 95% CI=0.77-1.06; recessive model: OR=0.95, 95% CI=0.80-1.13). Similarly, no associations were found in all comparisons for endometrial cancer (Val/Met versus Val/Val: OR 0.97, 95% CI=0.77-1.21; Met/Met versus Val/Val: OR=1.02, 95% CI=0.73-1.42; dominant model: OR=0.98, 95% CI=0.77-1.25; recessive model: OR=1.02, 95% CI=0.87-1.20). In the subgroup analyses by source of control and ethnicity, no significant associations were found in any subgroup of population. This meta-analysis strongly suggests that COMT Val158Met polymorphism is not associated with increased endometrial and ovarian cancer risk.

Surrounding rock pressure of shallow-buried bilateral bias tunnels under earthquake

Liu, Xin-Rong,Li, Dong-Liang,Wang, Jun-Bao,Wang, Zhen Techno-Press 2015 Geomechanics & engineering Vol.9 No.4

By means of finite element numerical simulation and pseudo-static method, the shallow-buried bilateral bias twin-tube tunnel subject to horizontal and vertical seismic forces are researched. The research includes rupture angles, the failure mode of the tunnel and the distribution of surrounding rock relaxation pressure. And the analytical solution for surrounding rock relaxation pressure is derived. For such tunnels, their surrounding rock has sliding rupture planes that generally follow a "W" shape. The failure area is determined by the rupture angles. Research shows that for shallow-buried bilateral bias twin-tube tunnel under the action of seismic force, the load effect on the tunnel structure shall be studied based on the relaxation pressure induced by surrounding rock failure. The rupture angles between the left tube and the right tube are independent of the surface slope. For tunnels with surrounding rock of Grade IV, V and VI, which is of poor quality, the recommended reinforcement range for the rupture angles is provided when the seismic fortification intensity is VI, VII, VIII and IX respectively. This study is expected to provide theoretical support regarding the ground reinforcement range for the shallow-buried bilateral bias twin-tube tunnel under seismic force.

Two 3D Cd^II and Zn^II Complexes Based on Flexible Dicarboxylate Ligand and Nitrogen-containing Pillar: Synthesis, Structure, and Luminescent Properties

Liu, Liu,Fan, Yan-Hua,Wu, Lan-Zhi,Zhang, Huai-Min,Yang, Li-Rong Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.12

Two 3D isomorphous and isostructural complexes, namely, $[Zn(BDOA)(bpy)(H_2O)_2]_n$ (1) and $[Cd(BDOA)-(bpy)(H_2O)_2]_n$ (2); (BDOA = Benzene-1,4-dioxyacetic acid, bpy = 4,4'-bipyridine) were synthesized under hydrothermal conditions and characterized by means of elemental analyses, thermogravimetric (TG), infrared spectrometry, and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the triclinic system, space group P-1 and each metal ion in the complexes are six-coordinated with the same coordination environment. In the as-synthesized complexes, $BDOA^{2-}$ anions link central metal ions to form a 1D zigzag chain $[-BDOA^{2-}-Zn(Cd)-BDOA^{2-}-Zn(Cd)-]_{\infty}$, whereas bpy pillars connect metal ions to generate a 1D linear chain $[-bpy-Zn(Cd)-bpy-Zn(Cd)-]_{\infty}$. Both infinite chains are interweaved into 2D grid-like layers which are further constructed into a 3D open framework, where hydrogen bonds play as the bridges between the adjacent 2D layers. Luminescent properties of complex 1 showed selectivity for $Hg^{2+}$ ion.

Multiple Acyl-CoA Dehydrogenase Deficiency Presenting as Rhabdomyolysis After Gastrointestinal Endoscopy

Rong-Rong Liu,Qiu Han,Li Ma 대한신경과학회 2023 Journal of Clinical Neurology Vol.19 No.4

Senescence as A Consequence of Ginsenoside Rg₁ Response on K562 Human Leukemia Cell Line

Liu, Jun,Cai, Shi-Zhong,Zhou, Yue,Zhang, Xian-Ping,Liu, Dian-Feng,Jiang, Rong,Wang, Ya-Ping Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

Aims and Background: Traditional chemotherapy strategies for human leukemia commonly use drugs based on cytotoxicity to eradicate cancer cells. One predicament is that substantial damage to normal tissues is likely to occur in the course of standard treatments. Obviously, it is urgent to explore therapies that can effectively eliminate malignant cells without affecting normal cells. Our previous studies indicated that ginsenoside $Rg_1$ ($Rg_1$), a major active pharmacological ingredient of ginseng, could delay normal hematopoietic stem cell senescence. However, whether $Rg_1$ can induce cancer cell senescence is still unclear. Methods: In the current study, human leukemia K562 cells were subjected to $Rg_1$ exposure. The optimal drug concentration and duration with K562 cells was obtained by MTT colorimetric test. Effects of $Rg_1$ on cell cycle were analyzed using flow cytometry and by SA-${\beta}$-Gal staining. Colony-forming ability was measured by colony-assay. Telomere lengths were assessed by Southern blotting and expression of senescence-associated proteins P21, P16 and RB by Western blotting. Ultrastructural morphology changes were observed by transmission electron microscopy. Results: K562 cells demonstrated a maximum proliferation inhibition rate with an $Rg_1$ concentration of $20{\mu}\;mol{\cdot}L^{-1}$ for 48h, the cells exhibiting dramatic morphological alterations including an enlarged and flat cellular morphology, larger mitochondria and increased number of lysosomes. Senescence associated-${\beta}$-galactosidase (SA-${\beta}$-Gal) activity was increased. K562 cells also had decreased ability for colony formation, and shortened telomere length as well as reduction of proliferating potential and arrestin $G_2$/M phase after $Rg_1$ interaction. The senescence associated proteins P21, P16 and RB were significantly up-regulated. Conclusion: Ginsenoside $Rg_1$ can induce a state of senescence in human leukemia K562 cells, which is associated with p21-Rb and p16-Rb pathways.