Synthesis and Solution Properties of Zwitterionic Copolymer of Acrylamide with 3-[(2-Acrylamido)dimethylammonio]propanesulfonate

Hui Xiao,Jing Hu,Shuailin Jin,Rui Hai Li 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.9

A novel zwitterionic monomer 3-[(2-acrylamido)dimethylammonio]propanesulfonate (DMADAS) was designed and synthesized in this study. Then it was polymerized with acrylamide (AM) by free radical polymerization in 0.5 mol/L NaCl solution with ammonium persulfate ((NH4)2S2O8) and sodium sulfate (NaHSO3) as initiator. The structure and composition of DMADAS and acrylamide-3-[(2-acrylamido)- dimethylammonio]propanesulfonate copolymer (P-AM-DMADAS) were characterized by FT-IR spectroscopy, 1H NMR and elemental analyses. Isoelectric point (IEP) of P-AM-DMADAS was tested by nanoparticle size and potential analyzer. Solution properties of copolymer were studied by reduced viscosity. Antipolyelectrolyte behavior was observed and was found to be enhanced with increasing DMADAS content in copolymer. The results showed that the viscosity of P-AM-DMADAS is 5.472 dl/g in pure water. Electrolyte was added, which weakened the mutual attraction between sulfonic acid group and quaternary ammonium group. The conformation became loose, which led to the increase of reduced viscosity. The ability of monovalent and divalent cation influencing the viscosity of zwitterionic copolymer obeyed the following sequence: Li+ < Na+ < K+, Mg2+ < Ca2+ < Ba2+, and that of anion is in the order: Cl− < Br− < I−, CO3 2− > SO3 2− ≈ SO4 2−.

In-situ photocrosslinked hydroxide conductive membranes based on photosensitive poly(arylene ether sulfone) block copolymers for anion exchange membrane fuel cells

He, Rui,Wen, Pushan,Zhang, Hai-Ning,Guan, Shumeng,Xie, Guangyong,Li, Li-Zhong,Lee, Myong-Hoon,Li, Xiang-Dan Elsevier 2018 Journal of membrane science Vol.556 No.-

<P><B>Abstract</B></P> <P>A series of photocrosslinkable multi-block poly(arylene ether sulfone) copolymers containing various block lengths of hydrophilic segments were synthesized. For comparison, a series of random poly(arylene ether) copolymers were also synthesized. The anion exchange membranes(AEMs) were fabricated and in-situ photocrosslinking was carried out by UV irradiation in a swollen state. The microphase-separated morphologies of the multi-block membranes were characterized by SAXS and TEM experiments, and the membrane properties were investigated by measuring ion exchange capacity (IEC), water uptake, water swelling ratio, ionic conductivity, methanol permeability and alkaline stability. IECs and water uptakes of the crosslinked multi-block membranes were in the range of 1.11–1.42 meq g<SUP>−1</SUP> and 14.36–31.01% at 20 °C, respectively. The hydroxide conductivity was in the range of 11.38–25.00 mS cm<SUP>−1</SUP> at 20 °C, and showed a maximum value of 178.77 mS cm<SUP>−1</SUP> at 100 °C. The multi-block membranes exhibited low methanol permeability (2.75 × 10<SUP>−7</SUP> cm<SUP>2</SUP> s<SUP>−1</SUP>) at room temperature, which is one order of magnitude lower than that of Nafion® 117 (23.8 × 10<SUP>−7</SUP> cm<SUP>2</SUP> s<SUP>−1</SUP>). The crosslinked membranes showed excellent dimensional stability and alkaline stability with only a slight decrease in ionic conductivity. All the multi-block membranes showed superior properties compared to their corresponding random copolymers.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Multi-block poly(arylene ether sulfone) copolymers were synthesized for AEMs. </LI> <LI> <I>In-situ</I> photo-crosslinking was carried out by UV irradiation in hydrated states. </LI> <LI> The block copolymers exhibited hydrophilic/hydrophobic phase separated morphology. </LI> <LI> The block copolymers showed superior properties compare to the random copolymers. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Phylogeny and molecular evolution of the DMC1 gene within the StH genome species in Triticeae (Poaceae)

Xiao-Li Wang,Xing Fan,Jian Zeng,Li-Na Sha,Hai-Qin Zhang,Hou-Yang Kang,Rui-Wu Yang,Li Zhang,Chun-Bang Ding,Yong-Hong Zhou 한국유전학회 2012 Genes & Genomics Vol.34 No.3

To estimate the phylogeny and molecular evolution of a single-copy nuclear disrupted meiotic cDNA (DMC1) gene within the StH genome species, two DMC1 homoeologous sequences were isolated from nearly all the sampled StH genome species and were analyzed with those from seven diploid taxa representing the St and H genomes in Triticeae. Sequence diversity patterns and genealogical analysis suggested that (1) there is a close relationship among North American StH genome species;(2) the DMC1 gene sequences of the StH genome species from North America and Eurasia are evolutionarily distinct;(3) the StH genome polyploids have higher levels of sequence diversity in the St genome homoeolog than the H genome homoeolog;(4) the DMC1 sequence may evolve faster in the polyploid species than in the diploids; (5) high dN and dN/dS values in the St genome within polyploid species could be caused by low selective constraints or AT-biased mutation pressure. Our result provides some insight on evolutionary dynamics of duplicate DMC1 gene, the polyploidization events and phylogeny of the StH genome species.

B-cell Lymphoma 2 rs17757541 C>G Polymorphism was Associated with an Increased Risk of Gastric Cardiac Adenocarcinoma in a Chinese Population

Li, Qiong,Yin, Jun,Wang, Xu,Wang, Li-Ming,Shi, Yi-Jun,Zheng, Liang,Tang, Wei-Feng,Ding, Guo-Wen,Liu, Chao,Liu, Rui-Ping,Gu, Hai-Yong,Sun, Jia-Ming,Chen, Suo-Cheng Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.7

Aim: Apoptosis has been considered as a fundamental component in cancer pathogenesis, and related genetic factors might play an important role in gastric cardiac adenocarcinoma (GCA) genesis. Methods: We conducted a hospital based case.control study to evaluate the genetic effects of functional single nucleotide polymorphisms (SNPs): BCL2 rs17757541 C>G, BCL2 rs12454712 T>C, FAS rs2234767 G>A, FASL/FASLG rs763110 C>T, ERBB2 rs1136201 A>G and VEGFR2/KDR rs11941492 C>T on the development of GCA. A total of 243 GCA cases and 476 controls were recruited for the study and genotypes were determined using a custom-by-design 48-Plex SNPscan$^{TM}$ Kit. Results: The BCL2 rs17757541 C>G polymorphism was associated with increased risk of GCA. However, there was no significant associations with the other five SNPs. Stratified analyses indicated a significantly increased risk of GCA associated with the BCL2 rs17757541 C>G polymorphism among males, older patients and those with a history of smoking or drinking. Conclusion: These findings indicated that the functional polymorphism BCL2 rs17757541 C>G might contribute to GCA susceptibility. However, our results were limited by small sample size. Future larger studies are required to confirm our current findings.

Effect of Matrix Metalloproteinase on Autolysis of Sea Cucumber Stichopus japonicus

Li-Ming Sun,Ting-Ting Wang,Bei-Wei Zhu,Hai-Ling Niu,Rui Zhang,Hong-Man Hou,Gong-Liang Zhang,Yoshiyuki Murata 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.5

To investigate the relationship between matrix metalloproteinase (MMPs) and autolysis of sea cucumber Stichopus japonicus, the dermis homogenate was incubated at 25oC to induce autolysis. EDTA Na2 and 1,10-phenanthroline were used to verify the effect of MMPs on autolysis, which was measured by soluble protein and protein pattern. Soluble protein level increased during a 6-h autolysis process. SDS-PAGE demonstrated obvious protein degradation with the concomitant occurrence of degradation products. The above two indicators could be inhibited significantly by EDTA Na2 and 1,10-phenanthroline, indicating that MMPs might play a significant role in autolysis of sea cucumber.

Ursolic Acid Promotes Apoptosis of SGC-7901 Gastric Cancer Cells through ROCK/PTEN Mediated Mitochondrial Translocation of Cofilin-1

Li, Rui,Wang, Xia,Zhang, Xiao-Hong,Chen, Hong-Hai,Liu, Yan-Dong Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.22

Ursolic acid, extracted from the traditional Chinese medicine bearberry, can induce apoptosis of gastric cancer cells. However, its pro-apoptotic mechanism still needs further investigation. More and more evidence demonstrates that mitochondrial translocation of cofilin-1 appears necessary for the regulation of apoptosis. Here, we report that ursolic acid (UA) potently induces the apoptosis of gastric cancer SGC-7901 cells. Further mechanistic studies revealed that the ROCK1/PTEN signaling pathway plays a critical role in UA-mediated mitochondrial translocation of cofilin-1 and apoptosis. These findings imply that induction of apoptosis by ursolic acid stems primarily from the activation of ROCK1 and PTEN, resulting in the translocation of cofilin-1 from cytoplasm to mitochondria, release of cytochrome c, activation of caspase-3 and caspase-9, and finally inducing apoptosis of gastric cancer SGC-7901 cells.

Effects of Differential Distribution of Microvessel Density, Possibly Regulated by miR-374a, on Breast Cancer Prognosis

Li, Jian-Yi,Zhang, Yang,Zhang, Wen-Hai,Jia, Shi,Kang, Ye,Tian, Rui Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.3

Background: The discovery that microRNAs (miRNAs) regulate proliferation, invasion and metastasis provides a principal molecular basis of tumor heterogeneity. Microvessel distribution is an important characteristic of solid tumors, with significant hypoxia occurring in the center of tumors with low blood flow. The distribution of miR-374a in breast tumors was examined as a factor likely to be important in breast cancer progression. Methods: Breast tissue samples from 40 patients with breast cancer were classified into two groups: a highly invasive and metastatic group (HIMG) and a low-invasive and metastatic Group (LIMG). Samples were collected from the center and edge of each tumor. In each group, six specimens were examined by microRNA array, and the remaining 14 specimens were used for real-time RT-qPCR, Western blot and immunohistochemical analyses. Correlation analysis was performed for the miRNAs and target proteins. Follow-up was carried out during 28 months to 68 months after surgery, and survival data were analyzed. Results: In the LIMG, the relative content of miR-374a was lower in the center of the tumor than at its edge; in the HIMG, it was lower at the edge of the tumor, and miR-374a levels were lower in breast cancer tissues than in normal tissues. There was no difference between VEGF-A and VCAM-1 mRNA levels at the edge and center of the tumor; however, we observed a significant difference between VEGF-A and VCAM-1 protein expression levels in these two regions. There was a negative correlation between miR-374a and target protein levels. The microvessel density (MVD) was lower in the center of the tumor than at its edge in HIMG, but the LIMG vessels were uniformly distributed. There was a significant positive correlation between MVD and the number of lymph node metastases (Pearson correlation, r=0.912, P<0.01). The median follow-up time was 48.5 months. LIMG had higher rate of disease-free survival (100%, P=0.013) and longer median survival time (66 months) than HIMG, which had a lower rate of 75% and shorter median survival time (54 months). Conclusions: Our data demonstrated miR-374a to be differentially distributed in breast cancer; VEGF-A and VCAM-1 mRNA had coincident distribution, and the distribution of teh respective proteins was uneven and opposite to that for the miR-374a. These data might explain the differences in the distribution of MVD in breast cancer and variation in breast cancer prognosis.

Spreading behaviors of high-viscous nanofluid droplets impact on solid surfaces

Hai Long Liu,Xuefeng Shen,RUI WANG,Yuanping Huo,Changfeng Li,Junfeng Wang 한국유변학회 2019 Korea-Australia rheology journal Vol.31 No.3

In this work, the impact dynamics of high-viscous nanofluid droplets onto a solid surface has been investigated experimentally by means of high-speed camera visualization technique. We dispersed various nanoparticles (multiwall carbon nanotube (MWCNT), nano-graphene, and nano-graphite powder) into highviscous base fluid (epoxy resin) to obtain the stable and homogenous nanofluids without surfactant additives. The well dispersed nanofluids show different degree of shear-thinning behaviors, and the shear-thinning properties of those fluids have been characterized by the power-law rheology model. The dynamic contact angle (DCA), transient dimensionless height, and transient contacting factor along with the spreading time under different Weber numbers (We) have been investigated. The results show that the nanofluid with a lower shear viscosity over the entire range of the shear rates results in larger variations of the contacting factor and the dimensionless height. The effect of surface wettability on droplet impact behaviors is more significant for the fluid with higher shear viscosity and less shear-thinning degree during the receding phase. The latter spreading and receding motions of the droplet with higher shear viscosity and shearthinning degree are suppressed significantly, regardless of the Weber numbers in current study. Finally, a model based on experimental data has been proposed to predict the maximum spreading factor of high-viscous droplet impact on solid surface.

Molecular Dynamics Simulation to Investigate the Rake Angle Effects on Nanometric Cutting of Single Crystal Ni3Al

Rui-cheng Feng,Yong-nian Qi,Zong-xiao Zhu,Wen-yuan Song,Hai-yan Li,Mao-mao Wang,Zhi-yuan Rui,Feng-shou Gu 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.4

Molecular dynamics, an eff ective method to gain an insight into nanometric behaviour of materials, was employed to studythe nano-cutting behaviour of single crystal Ni 3 Al in nanometric scale. In this paper, comparisons were made for compressive/tensile stress, subsurface damage and surface roughness with three rake angles of a diamond tool. Subsurface damage waspartitioned by region and studied with work hardening in detail. A model for precise characterization of surface roughnesswas established with consideration of local surface fl uctuation. Simulation results showed that the chip thickness increasedas rake angle changed from negative to positive, and the boundary formed between tensile and compressive stress was inconsistent with the glide direction of stacking fault. Subsurface damage decreased as the increase of rake angle, and regularglide planes of stacking faults were found in front of the cutting tool. Further, the pinned dissociated 1/2 < 110 > superpartialdislocation with anti-phase boundary was demonstrated. The model was tested and characterized by implanted pits onperfect surface. Results showed that surface roughness can be well characterized, and an evident discrepancy was observedamong three rake angles, especially for 30° rake angle, which showed an distinct smooth surface compared with the others.

LEACH Protocol based Two-Level Clustering Algorithm

Zhen-rui Peng,Hong Yin,Hai-tang Dong,Hui Li 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.10

For wireless sensor networks, it is difficult to balance the energy distribution and reduce the energy consumption in the data transmission process. On the basis of the original LEACH protocol and level technique, a new method of cluster heads collection and two-level clustering transmission is proposed. By controlling the distances among the cluster heads, the uniform distribution of cluster heads is satisfied. And then using two-level mode, the data are transmitted to the base station. LEACH is compared with the improved method about the remaining energy and alive nodes. Simulation results show that the improved method can reduce the network consumption energy greatly and lengthens the network lifetime efficiently.