Selaginella austrotibetica (Selaginellaceae), a new spikemoss from Xizang, China

Meng-Hua Zhang,Jie Yang,Aleksandr Petrovich Shalimov,강종수,Xian Chun Zhang 국립생물자원관 2024 Journal of species research Vol.13 No.1

Selaginella austrotibetica, a new spikemoss species from China, is described. The species is epipetric and was found on a moss-covered rocky cliff by a riverbank. Morphologically, it is unlike any anisosporophyllous species in the genus Selaginella. However, it resembles species of the S. sanguinolenta group, especially similar to S. sajanensis in gross morphology, except for the characters of strobilus. The molecular phylogenetic analysis clearly showed that S. austrotibetica was nested within the anisosporophyllous species clade, forming a sister relationship with the clade of S. vaginata and S. xipholepis, and distinct from the S. sanguinolenta group, including S. sajanensis. Although S. austrotibetica is sister to the clade of S. vaginata and S. xipholepis, the species can be clearly distinguished by its sparse leaves on branches, dorsal leaves that are broad-ovate, base obtuse to rounded, margin denticulate or very shortly sparsely ciliolate, and leaves that are slightly thick and shiny. Therefore, we described Selaginella austrotibetica as a new species and discuss its phylogenetic relationships within the genus Selaginella.

Lateral Structural Performance of Column Frame Layer and Dou-Gong Layer in a Timber Structure

Xian-jie Meng,Tie-ying Li,Qing-shan Yang 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.2

In this study, a 1:2 scale model of a timber building with a column frame layer and a Dou-Gong layer was fabricated according to the construction method that prevailed during the Song dynasty, China (A.D. 960–1279). Three quasi-static tests were conducted on the model under three levels of vertical loads to study the seismic response of the column frame layer and Dou-Gong layer in a timber structure. The experimental results indicated that the ultimate loading state of the timber structure was mainly controlled by the lateral displacement of the column frame layer. The hysteretic behaviour and stiffness characteristics of the column frame layer were quite similar to those of the overall structure. The stiffness of the Dou-Gong layer was much higher than that of the column frame layer, and no stiffness degradation was observed in the Dou-Gong layer. Fairly little energy was dissipated by the Dou-Gong layer; more than 80% of the structural energy dissipation that occurred was attributable to the column frame layer. Moreover, based on the deformation features of the column frame and Dou-Gong layer, a theoretical model for estimating the restoring force of the overall structure was established.

Fault Tolerant H∞ Control for a Class of Polynomial Non-linear Discrete-time Systems

Xian-Ji Meng,Guang-Hong Yang 제어·로봇·시스템학회 2012 International Journal of Control, Automation, and Vol.10 No.4

This paper studies the fault tolerant control (FTC) problem for a class of polynomial nonlinear discrete-time systems with guaranteed H∞ performance in the presence of actuator faults. The con-cerned fault is considered as a multi-model of the typical aberration in actuators’ effectiveness. A quadratic-like polynomial Lyapunov function is presented for the H∞ specification. The main contribution of this paper is that the effect of the nonlinear terms appear in FTC analysis is described as an index in order to transform the controller design into a semi-definite programming (SDP). A numerical example is given to verify the applicability of this new approach for the nonlinear FTC synthesis.

100W-class arcjet thrusters with ammonia propellant

Xian MENG,Wenxia PAN,Chengkang WU 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

Selaginella subvaginata (Selaginellaceae), a new spikemoss from China

Xian-Chun Zhang,Aleksandr Petrovich Shalimov,강종수,Meng-Hua Zhang 국립생물자원관 2020 Journal of species research Vol.9 No.3

Selaginella vaginata is a common montane species with broad distribution in China and the Himalaya region, and several species that are morphologically similar to S. vaginata are distributed in Asia. The taxonomic revision of S. vaginata and related species was performed by morphological comparison of leaves, strobili, and spores, and phylogenetic analysis. Based on these results, a new species, S. subvaginata, sp. nov., has been identified. Morphologically, S. subvaginata has intermediate form between S. vaginata and S. repanda, which differs mainly in its main stem being erect, dorsal leaves long-ciliolate on inner margin and outer margin denticulate or with 2-4 cilia at base (long-ciliolate on both inner and outer margins in S. vaginata, denticulate on both inner and outer margins in S. repanda), and acroscopic base of ventral leaves long ciliolate (sparsely long ciliolate in S. vaginata, short ciliolate to denticulate in S. repanda). Moreover, phylogenetic analysis using three chloroplast markers (rbcL, atpI, and psbA) revealed that S. subvaginata is a distinct species among the anisosporophyllous species clade in Selaginellaceae.

Dexamethasone Disrupts Cytoskeleton Organization and Migration of T47D Human Breast Cancer Cells by Modulating the AKT/mTOR/RhoA Pathway

Meng, Xian-Guo,Yue, Shou-Wei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Background: Glucocorticoids are commonly co-administered with chemotherapy to prevent drug-induced allergic reactions, nausea, and vomiting, and have anti-tumor functions clinically; however, the distinct effects of GC on subtypes of tumor cells, especially in breast cancer cells, are still not well understood. In this study, we aimed to clarify the effect of GC on subtypes of T47D breast cancer cells by focusing on apoptosis, cell organization and migration, and underluing molecular mechanisms. Materials and Methods: The cell scratch test was performed to observe the cell migration rate in T47D cells treated with dexamethasone (Dex). Hoechst and MTT assays were conducted to detect cell survival and rhodamine-labeled phalloidin staining to observe cytoskeleton dynamics. Related factors in the AKT/mTOR pathway were determined by Western blotting. Results: Dex treatment could effectively inhibit T47D breast cancer cell migration with disruption of the cytoskeletal dynamic organization. Moreover, the effect of Dex on cell migration and cytoskeleton may be mediated by AKT/mTOR/RhoA pathway. Although Dex inhibited T47D cell migration, it alone may not induce cell apoptosis in T47D cells. Conclusions: Dex in T47D human breast cancer cells could effectively inhibit cell migration by disrupting the cytoskeletal dynamic organization, which may be mediated by the AKT/mTOR/RhoA pathway. Our work suggests that glucocorticoid/Dex clinical use may prove helpful for the treatment of breast cancer metastasis.

Different Morphology of Hydroxyapatite Coatings on Titanium by Electrophoretic Deposition

Meng, Xian Wei,Kwon, Tae Yub,Kim, Kyo Han Trans Tech Publications, Ltd. 2006 Key Engineering Materials Vol.309 No.-

<P>Commercial hydroxyapatite powders were electrophoretically deposited on titanium substrates. In this study, the effect of deposition durations and applied voltages on deposition yield was investigated. Green and sintered coatings were studied by SEM and XRD. It was observed that by applying low voltages and presedimentation, uniform and smooth hydroxyapatite coating can be prepared. In order to obtain roughened hydroxyapatite coatings, high voltages have to be applied. It was concluded that experimental conditions of powder concentration, applied potential, and presedimentation have a significant effect on the deposited coating morphology.</P>

Involvement of Nuclear Factor Kappa B in High-Fat Diet-Related Pancreatic Fibrosis in Rats

( Ming Xian Yan ),( Hong Bo Ren ),( Yi Kou ),( Min Meng ),( Yan Qing Li ) 대한소화기학회 2012 Gut and Liver Vol.6 No.3

Background/Aims: High-fat diets contribute to pancreatic fibrogenesis, but the pathogenesis remains unclear. This study investigated the role of nuclear factor kappa B (NF-κB) in high-fat diet-induced pancreatic fi brosis in rats. Methods: Male Wistar rats were fed a high-fat diet or standard normal chow for 20 weeks. Pancreatic fibrosis was determined by Sirius red staining. Immunohistochemical staining, reverse transcription-polymerase chain reaction and Western blotting were used to identify NF-κB-associated genes or protein expressions. Results: Infl ammation, fat deposition, pancreatic stellate cell activation and fi brosis were observed in the pancreases of the high-fat diet group. NF-κB subunit p65 (NF-κB/ p65) expression was localized to the nucleus, and intercellular adhesion molecule 1 (ICAM-1) was over-expressed. Pancreatic gene expression levels of NF-κB/p65, ICAM-1 and tumor necrosis factor α were all elevated signifi cantly in rats fed a high-fat diet compared with control rats. Western blotting also revealed signifi cantly increased levels of ICAM-1 and nuclear NF-κB/p65 in rats fed high-fat diets comparison with control rats. Conclusions: NF-κB is involved in high-fat diet-related pancreatic fi brosis. (Gut Liver 2012;6:381-387)

역사학 : 장영덕(張永德)과 오대(五代)에서 송초(宋初)의 정치(政治)

맹헌옥 ( Xian Yu Meng ),고도민 ( Diao Min Ja ) 경희대학교 인문학연구소 2007 인문학연구 Vol.11 No.-

Calcium-sensing receptor-mediated L-tryptophan-induced secretion of cholecystokinin and glucose-dependent insulinotropic peptide in swine duodenum

Xiuying Zhao,Yihan Xian,Chao Wang,Liren Ding,Xianglong Meng,Weiyun Zhu,Suqin Hang 대한수의학회 2018 JOURNAL OF VETERINARY SCIENCE Vol.19 No.2

This study aimed to elucidate the effect of tryptophan (Trp) on gut hormone secretion as well as the roles of the calcium-sensing receptor (CaSR)and its downstream signaling pathway in gut hormone secretion by assessing swine duodenal perfusion in vitro. Swine duodenum was perfusedwith Krebs-Henseleit buffer as a basal solution. Various concentrations (0, 10, and 20 mM) of Trp were applied to investigate its effect ongut hormone secretion. A CaSR antagonist was used to detect the involvement of CaSR and its signal molecules. The 20 mM Trp concentrationpromoted the secretion of cholecystokinin (CCK) and glucose-dependent insulinotropic peptide (GIP), elevated the mRNA level of CaSR,and upregulated the protein levels of CaSR, protein kinase C (PKC), and inositol trisphosphate receptor (IP3R). However, NPS 2143, aninhibitor of CaSR, attenuated the CCK and GIP release, reduced the mRNA level of CaSR, and decreased the protein levels of CaSR, PKC,and IP3R with 20 mM Trp perfusion. The results indicate that CCK and GIP secretion can be induced by Trp in swine duodenum in vitro,and the effect is mediated by CaSR and its downstream signal molecules PKC and IP3R.