Microstructure and Mechanical Properties of Cold Drawn Ti–Nb–Ta–Zr–O Wires for Orthodontic Applications

Wei‑dong Zhang,Junye Ren,Bin Liu,Yong Liu,Zhenggang Wu,Jingwen Qiu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.7

Ti–36Nb–2Ta–3Zr–0.35O (TNTZO) alloy is an excellent candidate for biomedical applications. In this study, a new methodcombining cold-swaging and cold-drawing was used to fabricate the TNTZO alloy wires with 0.3 mm diameter for orthodonticapplications. The microstructure and mechanical properties of cold-drawn and annealed TNTZO wires (referred toas TNTZO0.3and TNTZO0.3(HT), respectively) were investigated. The results show that the microstructure of cold drawnTNTZO0.3consists of main-sized elongated grains with 70 nm width. After annealing at 700 °C for 5 min, the microstructureof TNTZO0.3(HT) wires becomes equiaxial with a grain size of ~ 5 μm. The cold drawn TNTZO0.3wires exhibit improvedmechanical properties, higher tensile strength (about 1000 MPa) and similar elastic modulus (69 GPa), compared to annealedTNTZO0.3(HT) wires. Besides, TNTZO0.3has higher creep resistance and lower stress exponent (around 2), compared to Tiwires and TC4 wires with the same diameter. These results prove that TNTZO0.3wires have most of the ideal characteristicsof orthodontic wires.

Homoisoflavanones from Polygonatum odoratum Rhizomes Inhibit Advanced Glycation End Product Formation

Wei Dong,Hai Bo Shi,Heng Ma,Yan Bo Miao,Tong Jun Liu,Wei Wang 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.5

Protein glycation inhibitors from Polygonatum odoratum rhizomes were investigated using a bioassay-guided procedure to characterize active compounds for preventing and treating diabetic complications. The EtOH extract and soluble fractions were evaluated using an in vivo model of renal advanced glycation end-product (AGE) accumulation in streptozotocin-induced diabetic rats and an in vitro bovine serum albumin-glucose assay. Three homoisoflavanones 3-(4’-hydroxybenzyl)-5,7-dihydroxy-6-methyl-8-methoxychroman-4-one (1), 3-(4’-hydroxybenzyl)-5,7-dihydroxy-6,8-dimethylchroman-4-one (2), and 3-(4’-methoxybenzyl)-5,7-dihydroxy-6-methyl-8-methoxychroman-4-one (3), isolated from the active CHCl3-soluble fraction of the EtOH extract, were subjected to in vitro bioassays to evaluate their inhibitory activities against AGE formation. All the isolates inhibited AGE formation more effectively than the positive control, aminoguanidine. These results indicate that pending further study these compounds could be used as novel natural product drug for mitigating diabetic complications.

Anti-HIV-1 Activity of Lignans from the Fruits of Schisandra rubriflora

Wei-Lie Xiao,Rui-Rui Wang,Wei Zhao,Ren-Rong Tian,Shan-Zhai Shang,Liu-Meng Yang,Jian-Hong Yang,Jian-Xin Pu,Yong-Tang Zheng,Han-Dong Sun 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.5

This study investigated the 70% aqueous acetone extract of the fruits of Schisandra rubriflora which led to the isolation of eight lignans, including a new isolate, rubrisandrin C (1), and seven known lignans (2-8) . The structure of 1 was established by extensive 1D and 2D NMR spectroscopy and its absolute stereochemistry was determined by CD spectrum. Compounds 1-5 and 7-8 were evaluated for their anti-HIV-1 activity that showed inhibitory activity on HIV-1IIIB induced syncytium formation with EC50 values in the range of 2.26~20.4 μg/mL. Compounds 1 and 7 exerted their obvious protection of HIV-1IIIB inducted MT-4 host cells lytic effects with a selectivity index of 15.4 and 24.6, respectively.

Analysis the role of arabidopsis CKRC6/ASA1 in auxin and cytokinin biosynthesis

Dong-Wei Di,Lei Wu,Pan Luo,Li Zhang,Tian-Zi Zhang,Xue Sun,Shao-Dong Wei,Chen-Wei An,Guang-Qin Guo 한국식물학회 2016 Journal of Plant Biology Vol.59 No.2

The crosstalk between auxin and cytokinin (CK) is important for plant growth and development, although the underlying molecular mechanisms remain unclear. Here, we describe the isolation and characterization of a mutant of Arabidopsis Cytokinin-induced Root Curling 6 (CKRC6), an allele of ANTHRANILATE SYNTHASE ALPHA SUBUNIT 1 (ASA1) that encodes the á-subunit of AS in tryptophan (Trp) biosynthesis. The ckrc6 mutant exhibits root gravitropic defects and insensitivity to both CK and the ethylene precursor 1-aminocyclopropane-1-carboxylicacid (ACC) in primary root growth. These defects can be rescued by exogenous indole-3-acetic acid (IAA) or tryptophan (Trp) supplementation. Furthermore, our results suggest that the ckrc6 mutant has decreased IAA content, differential expression patterns of auxin biosynthesis genes and CK biosynthesis isopentenyl transferase (IPT) genes in comparison to wild type. Collectively, our study shows that auxin controls CK biosynthesis based on that CK sensitivity is altered in most auxin-resistant mutants and that CKs promote auxin biosynthesis but inhibit auxin transport and response. Our results also suggest that CKRC6/ASA1 may be located at an intersection of auxin, CK and ethylene metabolism and/or signaling.

Chemical Constituents from the Aerial Parts of Isodon coetsa and their Cytotoxicity

Wei Zhao,Jian Xin Pu,Xue Du,Yong Zhao,Fei He,Hai Bo Zhang,Yong Bo Xue,Wei Lie Xiao,Han Dong Sun,Ying Li Wu,Guo Qiang Chen 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.12

Three new compounds (1-3), including a neolignan, a triterpenoid, and a diterpenoid, together with twenty known compounds (4-23), were isolated from the aerial parts of Isodon coetsa. Their structures and relative configurations were elucidated on the basis of spectroscopic data. Compounds 1, 3, 5-9, 11-13, 16-17, and 19-23 were evaluated for their cytotoxicity against HT-29, BEL-7402, and SK-OV-3 human tumor cell lines. Compound 7 showed significant inhibitory effects on all three types of cells, with IC50 values of 2.52, 3.06, 2.14 μM, respectively.

A New C-10 Acetylene and A New Triterpenoid from Conyza canadensis

Wei Dong Xie,Xue Gao,Zhong Jian Jia 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.5

From the whole plants of Conyza canadensis (Compositae), a new C-10 acetylene, namely 8R, 9R-dihydroxymatricarine methyl ester (1), and a new triterpenoid, namely 3β, 16β, 20β–trihydroxytaraxast- 3-O-palmitoxyl ester (4), were isolated along with eleven known compounds (2, 3, 5-13). The structures of all 13 compounds were elucidated on the basis of their spectral data. The antibacterial activities of compounds 1-3 were evaluated.

Fracture toughness improvement of epoxy resins with short carbon fibers

Wei Dong,Fan-Long Jin,박수진,Heng-Chang Liu 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

This study examined the thermal stability and fracture toughness of diglycidylether of bisphenol-A (DGEBA)/short carbon fiber (SCF) composites using several techniques. The thermal stability of the DGEBA/SCF composites was similar to that of neat epoxy resin. The fracture toughness of the composites was significantly improved relative to the neat resin. The SEM micrographs indicated that a relatively rough surface with shear deformation and tortuous cracks was formed, thereby preventing deformation and crack propagation and inducing higher fracture toughness in the DGEBA/SCF composites.

A Rerouting-Controlled ISL Handover Protocol For LEO Satellite Networks

( Wei Dong ),( Junfeng Wang ),( Minhuan Huang ),( Jian Tang ),( Hongxia Zhou ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.10

In this paper, a rerouting-controlled ISL (Inter-Satellite link) handover protocol for LEO satellite networks (RCIHP) is proposed. Through topological dynamics and periodic characterization of LEO satellite constellation, the protocol firstly derives the ISL related information such as the moments of ISL handovers and the intervals during which ISLs are closed and cannot be used to forward packet. The information, combined with satellite link load status, is then been utilized during packet forwarding process. The protocol makes a forwarding decision on a per packet basis and only routes packets to living and non-congested satellite links. Thus RCIHP avoids periodic rerouting that occurs in traditional routing protocols and makes it totally unnecessary. Simulation studies show that RCIHP has a good performance in terms of packet dropped possibility and end-to-end delay.

Estimation of shallow groundwater ages and circulation rates in the Henan Plain, China: CFC and deuterium excess methods

Wei-hong Dong,Bo Kang,Shang-hai Du,Xu-fei Shi 한국지질과학협의회 2013 Geosciences Journal Vol.17 No.4

CFC age and deuterium excess methods were applied to the estimation of groundwater circulation rates in the Quaternary shallow groundwater system of the Henan Plain. The results provide a basis for groundwater renewability evaluation. The spatial distribution of CFC age shows that the groundwater system mainly comprises modern water, less than 50 a. The groundwater of less than 30 a was in the piedmont zone of the Taihang, Funiu, and Dabie Mountains, indicating short groundwater residence times,and fast groundwater cycling, with circulation rates of 27–31 m/d. Groundwater cycling along the Yellow River was also rapid because of exchange with the Yellow River. The circulation rates were 34–54m/d. In the areas around Tongxu, Shangqiu, Taikang, Xiangcheng,in the middle of the study area, and east of Huaxian-Changyuan and Xixian, Gushi in the south, groundwater age was 30–40 a, suggesting a longer groundwater residence time. The groundwater cycle in these areas was slower than in the piedmonts, and the area along the Yellow River. The circulation rates were 15–26 m/d. In the areas of Luyi, Yongcheng, Zhumadian, Xincai and Huaibin,the groundwater age was older than 40 a, with the longest residence times and slowest circulation rates (~12 m/d). The correlation between groundwater age and deuterium excess averages for the northern, central, southern shallow groundwater systems and the <30 a, 30–40 a, >40 a groundwater age divisions was strong (R = 0.9714), showing that the groundwater residence time embodied by the deuterium excess parameter was consistent with groundwater age estimated using the CFC method.

Identifying a Cinnamoyl Coenzyme A Reductase (CCR) Activity with 4-Coumaric Acid: Coenzyme A Ligase (4CL) Reaction Products in Populus tomentosa

Dong-Dong Wang,Hua Bai,Wei-Qi Chen,Hai Lu,Xiang-Ning Jiang 한국식물학회 2009 Journal of Plant Biology Vol.52 No.5

A cinnamoyl coenzyme A reductase (CCR, EC 1.2.1.44), one of the key enzyme involved in lignin biosynthesis, was cloned from Populus tomentosa (Chinese white poplar). At the same time, a 4CL1 gene was cloned from P. tomentosa, too. The two genes were subcloned in pQE31 vector and expressed in Escherichia coli M15. Both of them were purified by Ni-NTA. Purified CCR protein was digested by trypsin and analyzed by HPLC-MS; the peptide segments had 27% similarity with the sequence of the CCR protein. 4CL was thought to be a neighbor enzyme of CCR in lignin biosynthesis. In this paper, a 4CL1 from P. tomentosa was cloned, and its enzyme reaction products were extracted for the substrates of CCR. Three 4CL1 enzyme reaction products were monitored by HPLC-MS and then the CCR enzyme reaction was detected by GC-MS. In the CCR reaction, the three corresponding aldehyde (p-coumaraldehyde, caffealdehyde, and coniferaldehyde) were detected and identified by Frontier3 software. The results showed that the CCR that we cloned from P. tomentosa had affinities with 4CL1 enzyme reaction products and a ptCCR that was cloned from aspen (Li et al., Plant Cell Physiol 46(7):1073–1082, 2005) only had affinity with feruloyl-CoA. The different results maybe depend on the different study method. The method of exacting 4CL enzyme products as the substrates of CCR in the paper was reliable and can be used in lignin biosynthesis network to detect the enzymes in the neighborhood that depended on the polarity of the substrates and products. This CCR gene had eight homology sequence CCR gene when a BLAST was conducted in Populus trichocarpa genome database. The CCR homology genes in Populus suggested that some CCRs may take part in the lignin biosynthesis, too. The gene family would be the hot spot in the future study.