PAN Unit의 단일중합체와 공중합체에서의 배향에 관한 연구

박해랑,류주환 충남대학교 산업기술연구소 2003 산업기술연구논문집 Vol.18 No.1

Polyacrylonitrile(PAN) is a well-known crystalline polymer. Even when PAN is in its atactic configuration, as is usual, the crystallinity still strongly persists. This is due to the strong interaction between the nitrile groups. Hence much interest has been focused on the elucidation of the conformation of PAN. However, a full agreement on the crystalline morphology and the conformational state of individual polymer chains is yet to be achieved. In this study, we used as samples a PAN homopolymer and an AN-methyl acrylate(MA) copolymer. In the latter, MA is considered as a way of introducing a slight structural perturbation to the AN sequence in the homopolymer. Then the infrared dichroism technique was used to follow the behavior of orientation as a function of the extension. In carrying out these experiments, detailed considerations on the conformational structure of the PAN chains were given on the molecular basis. As a result, we found that the orientation behavior of the unperturbed AN sequences was more sensitive to the extension and its linearity of the chains was higher than the perturbed counterpart, in good agreement with the conjecture on the molecular level.

ST6Gal-I Predicts Postoperative Clinical Outcome for Patients with Localized Clear-cell Renal Cell Carcinoma

Liu, Hai-Ou,Wu, Qian,Liu, Wei-Si,Liu, Yi-Dong,Fu, Qiang,Zhang, Wei-Juan,Xu, Le,Xu, Jie-Jie Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Hyperactivated ${\alpha}2$-6-sialylation on N-glycans due to overexpression of the Golgi enzyme ${\beta}$-galactoside: ${\alpha}2$-6-sialyltransferase (ST6Gal-I) often correlates with cancer progression, metastasis, and poor prognosis. This study was aimed to determine the association between ST6Gal-I expression and the risk of recurrence and survival of patients with localized clear-cell renal cell carcinoma (ccRCC) following surgery. We retrospectively enrolled 391 patients (265 in training cohort and 126 in validation cohort) with localized ccRCC underwent nephrectomy at a single center. Tissue microarrays were constructed for immunostaining of ST6Gal-I. Prognostic value and clinical outcomes were evaluated. High ST6Gal-I expression was associated with Fuhrman grade (p<0.001 and p=0.016, respectively) and the University of California Los-Angeles Integrated Staging System (UISS) score (p=0.004 and p=0.017, respectively) in both cohorts. Patients with high ST6Gal-I expression had significantly worse overall survival (OS) (p<0.001 and p<0.001, respectively) and recurrence free survival (RFS) (p<0.001 and p=0.002, respectively) than those with low expression in both cohorts. On multivariate analysis, ST6Gal-I expression remained associated with OS and RFS even after adjusting for the UISS score. Stratified analysis suggested that the association is more pronounced among patients with low and intermediate-risk disease defined by the UISS score. High ST6Gal-I expression is a potential independent adverse predictor of survival and recurrence in ccRCC patients, and the prognostic value is most prominent in those with low and intermediate-risk disease defined by the UISS score.

Adsorption of Bovine Serum Albumin onto Tannic Acid-Immobilized Chitosan Resin

Hai-yan Li,Hai-mei Liu,Qin Zhao 한국섬유공학회 2020 Fibers and polymers Vol.21 No.11

A novel tannic acid-immobilized chitosan resin (TICR) was prepared by Mannich reaction for the adsorption ofproteins. The physical properties of TICR were characterized and the effects of contact time, pH, and initial concentration of(bovine serum albumin) BSA on its adsorption by TICR were investigated. The Langmuir isotherm model was applied todescribe the adsorption isotherm. The equilibrium data are fitted to the Langmuir isotherm model. The maximum monolayerBSA adsorption capacities of TICR were found to be 1.094, 1.487, and 1.694 mg/g at 298, 308, and 318 K, respectively. Furthermore, the data were analyzed on the basis of pseudo-first order, pseudo-second order, and intraparticle diffusionmodels. The correlation results suggested that the pseudo-second order model fitted the experimental data very well. Thethermodynamic study indicated that the adsorption process of BSA onto TICR was endothermic, and the Gibbs free energy(ΔGo), enthalpy (ΔHo), and entropy (ΔSo) of the adsorption process were calculated according adsorption isotherm data. TICRcould be reused for 10 times with only 19 % loss of adsorption capacity for BSA.

A Global Graph-based Approach for Transaction and QoS-aware Service Composition

( Hai Liu ),( Zibin Zheng ),( Weimin Zhang ),( Kaijun Ren ) 한국인터넷정보학회 2011 KSII Transactions on Internet and Information Syst Vol.5 No.7

In Web Service Composition (WSC) area, services selection aims at selecting an appropriate candidate from a set of functionally-equivalent services to execute the function of each task in an abstract WSC according to their different QoS values. In despite of many related works, few of previous studies consider transactional constraints in QoS-aware WSC, which guarantee reliable execution of Composite Web Service (CWS) that is composed by a number of unpredictable web services. In this paper, we propose a novel global selection-optimal approach in WSC by considering both transactional constraints and end-to-end QoS constraints. With this approach, we firstly identify building rules and the reduction method to build layer-based Directed Acyclic Graph (DAG) model which can model transactional relationships among candidate services. As such, the problem of solving global optimal QoS utility with transactional constraints in WSC can be regarded as a problem of solving single-source shortest path in DAG. After that, we present Graph-building algorithms and an optimal selection algorithm to explain the specific execution procedures. Finally, comprehensive experiments are conducted based on a real-world web service QoS dataset. The experimental results show that our approach has better performance over other competing selection approaches on success ratio and efficiency.

Reactive Synthesis of ZrB₂-based Ultra High Temperature Ceramics

Liu, Hai-Tao,Zhang, Guo-Jun The Korean Ceramic Society 2012 한국세라믹학회지 Vol.49 No.4

Reactive processing, such as reactive hot pressing (RHP) and reactive spark plasma sintering (R-SPS), is effective densification method to prepare $ZrB_2$-based ultra high temperature ceramics (UHTCs). The present paper reviewed some typical reactive processing of $ZrB_2$-based UHTCs. All the reactions from the starting materials in the reactive processing are thermodynamically favorable, which generate enough energy and driving force for the densification of the final products under a relatively low temperature. Besides, compared with non-reactive processing, anisotropic $ZrB_2$ grains, such as $ZrB_2$ platelets, can only be obtained in the reactive processing, resulting in an improvement of the mechanical properties.

The Effect of Postural Correction and Subsequent Balloon Inflation in Deformity Correction of Acute Osteoporotic Vertebral Fractures

Liu, Hai-Xiao,Xu, Cong,Shang, Ping,Shen, Yue,Xu, Hua-Zi The Korean Neurosurgical Society 2014 Journal of Korean neurosurgical society Vol.55 No.6

Objective : To determine deformity correction by postural correction and subsequent balloon inflation in acute vertebral compression fractures (OVCFs) and to examine the effect of bone mineral density on deformity correction. Methods : A totol of 50 acute OVCFs received balloon kyphoplasty. Lateral radiographs were taken and analyzed at five different time points : 1) preoperative, 2) after placing the patient in prone hyperextended position, 3) after balloon inflation, 4) after deposition of the cement, and 5) postoperative. All fractures were analyzed for height restoration of anterior (Ha), middle (Hm) and posterior (Hp) vertebra as well as Cobb angle and Kyphotic angle. The bone mineral density (BMD) of lumbar spine was measured by dual-energy X-ray absorptiometry. According to the T-score, the patients were divided into two groups which were osteoporosis group and osteopenia group. Results : Postoperative measurements of Ha, Hm and the Cobb angle demonstrated significant reduction of 4.62 mm, 3.66 mm and $5.34^{\circ}$ compared with the preoperative measurements, respectively (each p<0.05). Postural correction significantly increased Ha by 5.51 mm, Hm by 4.35 mm and improved the Cobb angle by $8.32^{\circ}$ (each p<0.05). Balloon inflation did not demonstrate a significant improvement of Ha, Hm or the Cobb angle compared with baseline prone hyperextended. Postural correction led to greater improvements of Ha, Hm and Cobb angle in osteoporosis group than osteopenia group (each p<0.05). Conclusion : In acute OVCFs, the height restoration was mainly attributed to postural correction rather than deformity correction by balloon inflation. BMD affected deformity correction in the process of postural correction.

Comprehensive Study on Associations Between Nine SNPs and Glioma Risk

Liu, Hai-Bo,Peng, Yu-Ping,Dou, Chang-Wu,Su, Xiu-Lan,Gao, Nai-Kang,Tian, Fu-Ming,Bai, Jie Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.10

Aim: Glioma cancer is the most common type of adult brain tumor. Recent genome-wide association studies (GWAS) have identified various new susceptibility regions and here we conducted an extensive analysis of associations between 12 single nucleotide polymorphisms (SNPs) and glioma risk. Methods: A total of 197 glioma cases and 197 health controls were selected, and 9 SNPs in 8 genes were analyzed using the Sequenom MassARRAY platform and Sequenom Assay Design 3.1 software. Results: We found the MAF among selected controls were consistent with the MAF from the NCBI SNP database. Among 9 SNPs in 8 genes, we identified four significant SNP genotypes associated with the risk of glioma, C/C genotype at rs730437 and T/T genotype at rs1468727 in ERGF were protective against glioma, whereas the T/T genotype at rs1799782 in XRCC1 and C/C genotype at rs861539 in XRCC3 conferred elevated risk. Conclusion: Our comprehensive analysis of nine SNPs in eight genes suggests that the rs730437 and rs1468727 in ERGF, rs1799782 in XRCC1 gene, and rs861539 in XRCC3 gene are associated with glioma risk. These findings indicate that genetic variants of various genes play a complex role in the development of glioma.

Characterization of LasR Protein Involved in Bacterial Quorum Sensing Mechanism of Pseudomonas aeruginosa

Hai Bo Liu,Kyong Pyo Koh,Joon Hee Lee,Jung Sun Kim,Sunghoon Park 한국생물공학회 2008 한국생물공학회 학술대회 Vol.2008 No.10

Transient filling simulations in unidirectional fibrous porous media

Liu, Hai Long,Hwang, Wook-Ryol The Korean Society of Rheology 2009 Korea-Australia rheology journal Vol.21 No.1

The incomplete saturation and the void formation during the resin infiltration into fibrous porous media in the resin transfer molding process cause failure in the final product during its service. In order to better understand flow behavior during the filling process, a finite-element scheme for transient flow simulation across the micro-structured fibrous media is developed in the present work. A volume-of- fluid (VOF) method has been incorporated in the Eulerian frame to capture the evolution of flow front and the vertical periodic boundary condition has been combined to avoid unwanted wall effect. In the microscale simulation, we investigated the transient filling process in various fiber structures and discussed the mechanism leading to the flow fingering in the case of random fiber distribution. Effects of the filling pressure, the shear-thinning behavior of fluid and the volume fraction on the flow front have been investigated for both intra-tow and the inter-tow flows in dual-scale fiber tow models.

Magmatic and metamorphic imprints from the root of an Archean continental arc: Evidence from the Qianhuai microblock in the North China Craton

Liu, Hai-Dong,Santosh, M.,Samuel, Vinod O. Elsevier 2019 Precambrian research Vol.321 No.-

<P><B>Abstract</B></P> <P>The Archean tectonic framework of the North China Craton (NCC) involved the assembly of several micro-continents along zones of ocean closure during the late Neoarchean, followed by high-grade metamorphism associated with the final assembly and cratonization of continental blocks during Late Paleoproterozoic. Here we investigate a metamorphosed igneous suite comprising pyroxenite, gabbro and trondhjemite in association with charnockite from the margin of the Qianhuai micro-block with a view to understand the magmatic and metamorphic history and crustal evolution in the NCC during late Neoarchean. We present new data from field investigations, petrology, geochemistry and zircon U-Pb, REE and Lu-Hf analyses. Mineral phase equilibria modeling shows that the pyroxenite formed at P-T conditions of 1.5–1.6 GPa and 900–1000 °C, possibly representing underplating of high temperature basaltic magma at the base of the continental arc, with the subsequent metamorphic conditions estimated as 1.2–1.4 GPa and 840–870 °C from the metagabbros. Both metagabbro and pyroxenite show an anticlockwise P-T path characterized by initial heating followed by moderate to high-pressure metamorphism and cooling. The base of a thickened arc is a viable tectonic settings to account for this scenario. Geochemical data suggest that the pyroxenite-gabbro-trondhjemite association represent the fractionated sequence from a common mafic magma, whereas the charnockite corresponds to anhydrous lower crustal melts. The high degree of hydration of the mafic and ultramafic units suggest retrograde metamorphism under hydrous conditions associated with slab subduction. The mafic-ultramafic rocks fall within the field of island arc tholeiite and the trondhjemite falls in the field of oceanic arc basalt. Geochemical data indicate arc signature of the rocks and the subduction processes involved in the generation of precursor basaltic melts that underplated the overriding arc crust and triggered lower crustal melting.</P> <P>The U-Pb data on magmatic zircon grains from the trondhjemite, metagabbro, pyroxenite and charnockite yield emplacement ages of 2481 Ma, 2449 Ma and 2464 and 2480 Ma and suggest subduction-related magmatism during Neoarchean-early Paleoproterozoic transition, followed by high grade metamorphism at ca. 1.94 Ga as indicated by the lower intercept ages. Zircon REE data confirm the magmatic crystallization history. The zircon Lu-Hf data show consistently positive εHf(t) values (0.5–11.7) and plot between CHUR and new crust line suggesting that depleted mantle sources contributed significantly to arc building and crustal growth. The computed model ages suggest that the magma source involved Neoarchean-Mesoarchean juvenile components. Our study provides important insights into magmatic and metamorphic processes at the base of an Archean continental arc and contributes to the understanding of the formation and growth of micro-continents within the NCC.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Magma underplating at 1.5–1.6 GPa and 900–1000 °C and metamorphism at 1.2–1.4 GPa and 840–870 °C. </LI> <LI> Source magma shows island arc tholeiite affinity in convergent margin. </LI> <LI> Magma emplacement during Neoarchean – early Paleoproterozoic transition. </LI> <LI> Vertical growth of the continental arc aided by magma addition from depleted mantle source. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>