Intermedins A and B; New Metabolites from Schisandra propinqua var. intermedia

Li, Hong-Mei,Lei, Chun,Luo, Yong-Ming,Li, Xiao-Nian,Li, Xiao-Lei,Pu, Jian-Xin,Zhou, San-Yun,Li, Rong-Tao,Sun, Han-Dong 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.6

A new dibenzocyclooctadiene lignan, intermedin A (1), and a new natural bisabolane sesquiterpenoid, intermedin B (2), were isolated from the aerial parts of Schisandra propinqua var. intermedia. Their structures were elucidated on the basis of extensive spectroscopical analysis.

Intermedins A and B; New Metabolites from Schisandra propinqua var. intermedia

Hong-Mei Li,Chun Lei,Yong-Ming Luo,Xiao-Nian Li,Xiao-Lei Li,Jian-Xin Pu,San-Yun Zhou,Rong-Tao Li,Han-Dong Sun 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.6

A new dibenzocyclooctadiene lignan, intermedin A (1), and a new natural bisabolane sesquiterpenoid, intermedin B (2), were isolated from the aerial parts of Schisandra propinqua var. intermedia. Their structures were elucidated on the basis of extensive spectroscopical analysis.

ent-Abietane Diterpenoids from Isodon xerophilus

Li Mei Li,Jian Xin Pu,Wei Lie Xiao,Han-Dong Sun 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.6

Three new ent-abietanoids, named xerophilusins XIV–XVI, and four known analogues, as well as four known chemical constituents were isolated from the leaves of Isodon xerophilus. Their structures were elucidated by extensive spectroscopic studies, and comparison with literature data. In addition, the cytotoxic activity of the ent-abietanoids against chronic myelogenous leukemia (K562), stomach adenocarcinoma (MKN45), and hepatocellular carcinoma (HepG2) human cell lines was investigated and no activities were observed.

Effects of Reheating Time on Microstructure and Tensile Properties of SiCp/ 2024 Al-Based Composites Fabricated Using Powder Thixoforming

Pu Bo Li,Ti Jun Chen,Su Qing Zhang 대한금속·재료학회 2017 METALS AND MATERIALS International Vol.23 No.1

The present investigation addresses a new technology, named powder thixoforming, used to fabricate SiCp/ 2024 Al-based composites. The effects of reheating time on microstructure and mechanical properties have been studied. The results indicated that the quantity of liquid, the coarsening behavior of the primary particles, the subsequent plastic deformation occurring during thixoforging, and thus the resulting microstructural compactness and mechanical properties changed as a function of reheating time. The best comprehensive tensile properties of the composite, that is an ultimate tensile strength of 370 MPa and an elongation of 4.4%, were obtained after reheating for 80 min at 625 °C, which was an increase of 23.3% and a decrease of 57.7%, respectively, compared to the 2024 alloy thixoforged under the same conditions as the composite. The fracturing in the composites occurred through interconnecting cracked SiCp and debonded SiC/Al interfaces caused by a higher concentration of stress and a coalescence of microvoids.

Association between Pax8-PPARγ1 Rearrangement and Follicular Thyroid Cancer: a Meta-Analysis

Li, Hang-Yu,Xie, Zhi-Hao,Xu, Cong-Hui,Pu, Mei-Ling,Chen, Zi-Yan,Yu, Miao,Wang, Heng-Shu,Zhou, Chen-Ming,Pu, Chao-Yu,Liu, Wei Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.9

Background: Pax8 and peroxisome proliferator-activated receptor gamma 1 gene (Pax8-$PPAR{\gamma}1$) are important factors in tumors. Several studies have suggested that follicular thyroid cancer may arise from Pax8- $PPAR{\gamma}1$ rearrangement. In order to have a better understanding of the association between Pax8-$PPAR{\gamma}1$ rearrangement and follicular thyroid cancer, we conducted the presenmt meta-analysis. Materials and Methods: The information was extracted from PubMed, EMBASE and Web of Science. Statistic analysis was performed with Stata12.0 software. Odds ratios (ORs) were calculated using a fixed-effects model. We also performed heterogeneity and publication bias analyses. Results: Nine studies including 198 follicular thyroid cancer patients and 268 controls were considered eligible. The frequency of Pax8-$PPAR{\gamma}1$ rearrangement was significantly higher in the follicular thyroid cancer group than in the control group, with a pooled OR of 6.63 (95%CI=3.50-12.7). In addition, through subgroup analysis, the OR between Pax8-$PPAR{\gamma}1$ rearrangement and follicular thyroid cancer was 6.04 (95%CI = 3.18-11.5) when using benign tumor tissues as controls. The OR for the method subgroup was 9.99 (95% CI =4.86-20.5) in the RT-PCR. Conclusions: The final results demonstrated that Pax8-$PPAR{\gamma}1$ rearrangement has significant association with follicular thyroid cancer.

Explicit co-simulation with interface Jacobian approximation

Pu Li,Qi Yuan 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.3

Explicit co-simulation denotes a weak coupling of subsystems without iteration between the communication time points (macro-time points). Extrapolated polynomials are commonly used to represent coupling variables. The error introduced by the polynomials can induce instability. Partial derivatives of the interface variables are used in the iterative cosimulation (implicit or semi-implicit co-simulation) to enhance stability. However, repetition of macro-time step becomes a main drawback especially for practical applications. In this manuscript we approximate the interface Jacobian using a truncated matrix exponential and study the numerical behavior in the framework of explicit co-simulations. The stability is greatly improved compared to the classical explicit method. The error of the interface Jacobian approximation has been investigated. A supported pendulum is used to validate the proposed cosimulation method.

Effects of Fdft 1 gene silencing and VD3 intervention on lung injury in hypoxia-stressed rats

Pu Xiaoyan,Lin Xue,Qi Yinglian,Li Yinglian,Li Tiantian,Liu Yang,Wei Dengbang 한국유전학회 2022 Genes & Genomics Vol.44 No.10

Background: Hypoxia can induce lung injury such as pulmonary arterial hypertension and pulmonary edema. And in the rat model of hypoxia-induced lung injury, the expression of Farnesyl diphosphate farnesyl transferase 1 (Fdft 1) was highly expressed and the steroid biosynthesis pathway was activated. However, the role of Fdft 1 and steroid biosynthesis pathway in hypoxia-induced lung injury remains unclear. Objective: The study aimed to further investigate the relationship between Fdft1 and steroid biosynthesis pathway with hypoxia-induced lung injury. Methods: A rat model of lung injury was constructed by hypobaric chamber with hypoxic stress, the adenovirus interference vector was used to silence the expression of Fdft 1, and the exogenous steroid biosynthesis metabolite Vitamin D3 (VD3) was used to treat acute hypoxia-induced lung injury in rats. Results: Sh-Fdft 1 and exogenous VD3 significantly inhibited the expression of Fdft 1 and the activation of the steroid pathway in hypoxia-induced lung injury rats, which showed a synergistic effect on the steroid activation pathway. In addition, sh-Fdft 1 promoted the increase of pulmonary artery pressure and lung water content, the decrease of oxygen partial pressure and oxygen saturation, and leaded to the increase of lung cell apoptosis and the aggravation of mitochondrial damage in hypoxia-stressed rats. And VD3 could significantly improve the lung injury induced by hypoxia and sh-Fdft 1 in rats. Conclusions: Fdft 1 gene silencing can promote hypoxic-induced lung injury, and exogenous supplement of VD3 has an antagonistic effect on lung injury induced by Fdft 1 gene silencing and hypoxic in rats, suggesting that VD3 has a preventive and protective effect on the occurrence and development of hypoxia-induced lung injury.

Preparation and Characteristics of MnAlC Nanoparticles by Plasma Arc-Discharge

Li, Pu,Lee, Jung Goo,Dong, Xing Long,Choi, Chul Jin Trans Tech Publications, Ltd. 2011 Materials science forum Vol.675 No.-

<P>MnAlC nanoparticles were synthesized by plasma arc-discharge method. Heat treatment of these nanoparticles at temperature from 400 to 600 °C resulted in the formation of the ferromagnetic τ-phase. Most of the nanoparticles had nearly spherical shape, smooth surface and core/shell structure. The shells of the nanoparticles mainly consisted of Al2O3 and a small amount of Mn oxides. Though the saturation magnetization of MnAlC nanoparticles was lower than that of bulk samples due to the effect of nonmagnetic phases (β, γ2 and Mn3AlC) and the oxide shell, the highest coercivity, up to 5.6 kOe in the MnAlC magnets, was achieved when annealed at 500 °C for 30 min.</P>

A quasi-sequential parameter estimation for nonlinear dynamic systems based on multiple data profiles

Pu Li,Chao Zhao,Quoc Dong Vu 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.2

A three-stage computation framework for solving parameter estimation problems for dynamic systems with multiple data profiles is developed. The dynamic parameter estimation problem is transformed into a nonlinear programming (NLP) problem by using collocation on finite elements. The model parameters to be estimated are treated in the upper stage by solving an NLP problem. The middle stage consists of multiple NLP problems nested in the upper stage, representing the data reconciliation step for each data profile. We use the quasi-sequential dynamic optimization approach to solve these problems. In the lower stage, the state variables and their gradients are evaluated through integrating the model equations. Since the second-order derivatives are not required in the computation framework this proposed method will be efficient for solving nonlinear dynamic parameter estimation problems. The computational results obtained on a parameter estimation problem for two CSTR models demonstrate the effectiveness of the proposed approach.

Influence of coupling approximation on the numerical stability of explicit co-simulation

Pu Li,Qi Yuan 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.6

Co-simulation allows the parallelization of several subsystems in a distributed manner with data exchanges at discrete user-defined communication points (macro-time points). Between two macro-time points, subsystems are integrated in a local circumstance using specified solvers. By adopting the technique, the computational efficiency can be enhanced greatly without exposure of inner information. As a weak coupling, communication between subsystems is usually approximated by extrapolated or interpolated polynomials that may induce instability. Implicit or semi-implicit co-simulation with iteration of macro-time steps can improve stability behavior significantly. However, reinitialization may be unfeasible for realtime simulation or not supported by most commercial tools. Therefore, stabilized non-iterative co-simulation has been more popular that can be achieved either by appropriate communication techniques or by interface error estimations. However, the influence of the coupling approximations on numerical stability is not well understood. In this paper, the numerical stability of explicit co-simulation will be studied using different approximations of coupling techniques. The influence of communication schemes (parallel and sequential coupling scheme), least square as well as relaxation techniques using an applied force coupling approach will be investigated quantitatively with the help of a linear two-mass oscillator. A quarter car model is used to validate the stability analysis of the linear oscillator. The results indicate that by adopting appropriate coupling techniques, stability improvement can be accomplished. Higher order of extrapolation (interpolation) introduces damping to the distributed system while relaxation and least square approaches might trigger artificial oscillations.