Improvement of thermal behaviors of biodegradable poly(lactic acid) polymer: A review

Jin, Fan-Long,Hu, Rong-Rong,Park, Soo-Jin Elsevier Science Ltd 2019 Composites Part B, Engineering Vol.164 No.-

<P><B>Abstract</B></P> <P>Owing to its excellent mechanical properties, processability, and biodegradability, poly(lactic acid) (PLA) has been widely investigated in the past few decades as a biomaterial. However, the poor heat resistance of PLA severely limits its applicability. In this review, several heat resistance modification methods, such as nucleating agent addition, fiber reinforcement, compounding, blending, stereoisomer complexation, and chemical modification, have been reviewed and their related mechanisms have been discussed in brief.</P>

하천 퇴적물 중 PCBs 농도분포 및 발생원 해석

김영호(Rong Hu Jin),오정근(Jung Keun Oh),김종국(Jong Guk Kim),김경수(Kyoung Soo Kim) 大韓環境工學會 2010 대한환경공학회지 Vol.32 No.11

하천 퇴적물 중 PCBs 농도수준 파악과 발생원 추정을 위해 낙동강 수계를 대상으로 21개 지점을 선정하고 지점당 3개씩 총 63개의 샘플을 분석한 결과 퇴적물 표층에서 검출된 DL-PCBs 농도분포는 3.0~6,600(평균440) pg/g-dry의 범위였고 TEQ값은 <LOQ~3.0(평균 0.34) pgTEQ/g-dry의 범위였다. 추가적으로, 고농도로 검출된 지점에 대해 발생원을 추정하기 위하여 낙동강 유역을 상, 중 및 하류로 구분하고 각 유역 별 고농도 지점을 중심으로 상류 1지점, 중류 2지점, 하류 2지점에 대해 분석을 실시하였다. 그 결과 T-PCBs의 농도는 3.9~60 ng/g-dry였다. 오염원을 해석하기 위하여 전이성체 분석 데이터의 이성체별, 동족체별 농도분포 패턴을 확인하였다. 시료의 동족체별 이성체 패턴이 혼합된 제품의 동족체별 패턴과 유사한 것으로 나타났다. 낙동강 수계 표층 퇴적물의 발생원을 추적하기 위해 통계적 방법을 이용하여 전이성체 분석한 시료를 해석한 결과 군집분석에서는 PCBs 제품에 영향을 받는 그룹으로 분류되었고, 특히 Aroclor 1254와 1260 제품에 주된 영향을 받는 것으로 나타났다. 주성분분석 결과에서도 PCBs의 제품의 특성이 주로 나타났다. To investigate the relationship between polychlorinated byphenyls (PCBs) sources and concentration level in sediment, total 63 sediment samples with three-time sampling at one site were measured at 21 sites in Nakdong River. As a result of analysis, total concentrations and toxic equivalent (TEQ) concentration of Dioxin-like PCBs were ranged from 3.0 to 6,600 pg/g-dry with a mean value of 440 pg/g-dry and <LOQ to 3.0 pgTEQ/g-dry with a mean value of 0.34 pgTEQ/g-dry, respectively. In addition, 5 sampling sites detected high concentration level were selected in order to examine PCBs sources and total 209 congeners were analyzed. The subject sites were 1 site at the upper stream, 2 sites at the middle stream, and 2 sites at the down stream. The concentration level of total PCBs was ranged from 3.9 to 60 ng/g-dry. In order to comprehend pollution sources, data analysis using isomers and congeners patterns was conducted. The isomer patterns in each homologue showed similar between sediment and PCB products. In addition, statistical methods were used to PCBs sources identification. According to the cluster analysis, the sediment samples were classified as one group that influenced by PCBs products. The results showed that they were especially influenced by Aroclor 1254 and 1260 products. The principal component analysis also showed that the samples contained the characteristics of PCBs products.

마이크로파를 이용한 슬레이트 중 석면 무해화처리 연구

김영호 ( Rong-hu Jin ),김종국 ( Jong-guk Kim ),윤길도 ( Gil-do Yun ),송병주 ( Byung-joo Song ) 한국환경기술학회 2011 한국환경기술학회지 Vol.12 No.4

본 연구에서는 향후 대량으로 발생하게 될 석면 함유 폐슬레이트의 안정적 처리를 위해 고형화나매립과 같은 방법들에 비해 석면의 유해성을 근본적으로 제거하고 신속하고 대량 처리가 가능한 마이크로파를 이용한 석면 무해화 처리 가능성을 평가하였다. 슬레이트를 대상으로 2.45 GHz의 마이크로파를 사용하여 500℃, 600℃, 700℃, 800℃ 및 900℃에서 석면의 무해화 실험을 수행하였으며 PLM, SEM/EDS 및 XRD 분석 결과, 700℃ 이상에서 석면이 모두 무해화 되었으며 석면 본래의 섬유 결정구조가 사라졌고 다른 미세한 입자들로 바뀌어 섬유질이 재결정되었음을 알 수 있었다. XRD 패턴 분석 결과 700℃에서는 백석면의 피크는 모두 사라지고 calcite, calcium-silicate및 SiO2만이 존재하였으며 특히 calcite 성분이 주를 이루었다. 마이크로파 처리 후 슬레이트 중 중금속 함량 변화는 거의 없었으며 현행 폐기물관리법 시행규칙의 중금속의 함량 기준을 만족하고 있어 재활용에도 문제가 없는 것으로 나타났다. The objectives of this study are evaluating the possibilities of the treatment of ACS(Asbestos-containing slate) using microwave to overcome the existing problems such as the limit of landfill capacity and safe treatment of ACS. The experiments were conducted under the condition of various temperature(500℃, 600℃, 700℃, 800℃, and 900℃) using 2.45 GHz microwave aiming at ACS. Asbestos was destructed and the original fiber structure of Asbestos disappeared and the re-crystallization occurred at the temperature over 700℃. These results were confirmed using the analysis of PLM (polarized light microscope), SEM/EDS(scanning electron microscope/energy dispersive spectrometer), and XRD(X-ray diffraction). It was confirmed that all the peaks of chrysotile disappeared and calcite, calcium-silicate, and SiO2 remained at the temperature over 700℃ through the analysis of XRD pattern. The change of heavy metal contents in the samples was not found and the concentrations of heavy metal in the samples that Asbestos was destructed were below than the criteria on recycling of wastes.

Calpain-10 SNP43 and SNP19 Polymorphisms and Colorectal Cancer: a Matched Case-control Study

Hu, Xiao-Qin,Yuan, Ping,Luan, Rong-Sheng,Li, Xiao-Ling,Liu, Wen-Hui,Feng, Fei,Yan, Jin,Yang, Yan-Fang Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.11

Objective: Insulin resistance (IR) is an established risk factor for colorectal cancer (CRC). Given that CRC and IR physiologically overlap and the calpain-10 gene (CAPN10) is a candidate for IR, we explored the association between CAPN10 and CRC risk. Methods: Blood samples of 400 case-control pairs were genotyped, and the lifestyle and dietary habits of these pairs were recorded and collected. Unconditional logistic regression (LR) was used to assess the effects of CAPN10 SNP43 and SNP19, and environmental factors. Both generalized multifactor dimensionality reduction (GMDR) and the classification and regression tree (CART) were used to test gene-environment interactions for CRC risk. Results: The GA+AA genotype of SNP43 and the Del/Ins+Ins/Ins genotype of SNP19 were marginally related to CRC risk (GA+AA: OR = 1.35, 95% CI = 0.92-1.99; Del/Ins+Ins/Ins: OR = 1.31, 95% CI = 0.84-2.04). Notably, a high-order interaction was consistently identified by GMDR and CART analyses. In GMDR, the four-factor interaction model of SNP43, SNP19, red meat consumption, and smoked meat consumption was the best model, with a maximum cross-validation consistency of 10/10 and testing balance accuracy of 0.61 (P < 0.01). In LR, subjects with high red and smoked meat consumption and two risk genotypes had a 6.17-fold CRC risk (95% CI = 2.44-15.6) relative to that of subjects with low red and smoked meat consumption and null risk genotypes. In CART, individuals with high smoked and red meat consumption, SNP19 Del/Ins+Ins/Ins, and SNP43 GA+AA had higher CRC risk (OR = 4.56, 95%CI = 1.94-10.75) than those with low smoked and red meat consumption. Conclusions: Though the single loci of CAPN10 SNP43 and SNP19 are not enough to significantly increase the CRC susceptibility, the combination of SNP43, SNP19, red meat consumption, and smoked meat consumption is associated with elevated risk.

Clinical and Pathologic Features of Multifocal and Multicentric Breast Cancer in Chinese Women: A Retrospective Cohort Study

Mei-rong Zhou,Zhong-hua Tang,Jing Li,Jin-Hu Fan,Yi Pang,Hong-jian Yang,Shan Zheng,Jing-qiao Bai,Ning Lv,You-Lin Qiao,Feng Xu,Hai-zhi Qi 한국유방암학회 2013 Journal of breast cancer Vol.16 No.1

Purpose: This study aims to analyze the clinical-pathological characteristics of multifocal and multicentric breast cancer (MMBC) in Chinese women. Methods: Sixty-seven cases with MMBC were randomly collected and reviewed at seven hospitals in representative districts of China during 1999 to 2008. Results: The incidence of MMBC in breast cancer in China was 1.75%. Compared to those with unifocal breast cancer, women with MMBC were more likely to have larger tumor size, lymph node metastasis (59.70% vs. 45.62%) and stage III to IV (46.26% vs. 21.10%). The peak age at onset of MMBC was 40 to 49 years old and has been gradually increasing during 1999 to 2008. Most of the MMBC women were treated with surgery and adjuvant therapy. Conclusion: In China, the incidence of MMBC in breast cancer is significantly lower than that in Western countries. Compared to unifocal breast cancer, MMBC is biologically more aggressive. Most MMBC women underwent mastectomy, instead of breast conservation surgery.

Improved impact strength of poly(lactic acid) by incorporating poly(butylene succinate) and silicon dioxide nanoparticles

Fan-Long Jin,Rong-Rong Hu,박수진 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.5

The surface of silicon dioxide (SiO2) nanoparticles was treated with oleic acid, and the resulting surface properties were characterized. Bio-based poly(lactic acid) (PLA)/poly(butylene succinate)/SiO2 nanocomposites were fabricated via solution blending. The influence of the SiO2 content on the thermal stability, flexural properties, impact strength, and morphology of the prepared nanocomposites was investigated using several techniques. The impact strength of the nanocomposites with surface treated SiO2 (O-SiO2) nanoparticles substantially increased with increasing O-SiO2 content from 0 to 3wt%. Scanning electron microscopy imaging revealed that the nanocomposites with OSiO2 nanoparticles exhibited numerous tortuous cracks and ridges, indicating ductile deformation prior to fracturing.

Genomic rearrangement between wheat and Thinopyrum elongatum revealed by mapped functional molecular markers

Li-Jun Hu,Cheng Liu,Zi-Xian Zeng,Guang-Rong Li,Xiao-Jin Song,Zu-Jun Yang 한국유전학회 2012 Genes & Genomics Vol.34 No.1

Thinopyrum elongatum serves as an excellent gene pool for wheat improvement. Genes for resistance to many biotic and abiotic stresses have been transferred from Th. elongatum to wheat through chromosome manipulation. For breeding programs,molecular markers enable screening of a large number of genotypes for alien chromosome introgressions. The main objective of the present study was to develop and characterize EST (expressed sequence tags) and PLUG (PCR-based Landmark Unique Gene) markers that can distinguish Th. elongatum chromatin from the wheat genomes. A total of 258 mapped EST primer pairs and 46 PLUG primer pairs were tested on DNA from wheat Chinese Spring (CS) and CS-Th. elongatum addition lines. The results showed that 43 primer pairs could be effectively mapped to specific Th. elongatum chromosomes. Twenty-two of the 43 markers displayed similar homoeologous chromosome locations to hexaploid wheat. Nine markers mapped to different linkage groups between wheat and Th. elongatum, while 12 makers mapped on two or three different Th. elongatum chromosomes. A comparison of molecular marker locations indicated that Th. elongatum genome was closely related to the D genome of wheat, and chromosome rearrangements and duplication had occurred in Th. elongatum and the wheat genomes. The markers will be useful in comparative gene mapping, chromosome evolutionary analysis, and gene introgression for wheat improvement using Th. elongatum accessions as gene donors.

Resveratrol promotes mitochondrial energy metabolism in exercise-induced fatigued rats

Lou Xujia,Hu Yulong,Ruan Rong,Jin Qiguan 한국영양학회 2023 Nutrition Research and Practice Vol.17 No.4

BACKGROUND/OBJECTIVES: To investigate the effect and regulator y mechanism of resveratrol supplementation on the mitochondrial energy metabolism of rats with exercise- induced fatigue. MATERIALS/METHODS: Forty-eight Sprague-Dawley male rats were divided randomly into a blank control group (C), resveratrol group (R), exercise group (E), and exercise and resveratrol group (ER), with 12 rats in each group. Group ER and group E performed 6-wk swimming training with 5% wt-bearing, 60 min each time, 6 days a wk. Group ER was given resveratrol 50 mg/kg by gavage one hour after exercise; group R was only given resveratrol 50 mg/kg by gavage; group C and group E were fed normally. The same volume of solvent was given by gavage ever y day. RESULTS: Resveratrol supplementation could reduce the plasma blood urea nitrogen content, creatine kinase activity, and malondialdehyde content in the skeletal muscle, increase the total superoxide dismutase activity in the skeletal muscle, and improve the fatigue state. Resveratrol supplementation could improve the activities of Ca2+-Mg2+-ATPase, Na+-K+- ATPase, succinate dehydrogenase, and citrate synthase in the skeletal muscle. Furthermore, resveratrol supplementation could up-regulate the sirtuin 1 (SIRT1)-proliferator-activated receptor gamma coactivator-1α ( P G C -1 α)-nuclear respirator y factor 1 pathway. CONCLUSIONS: Resveratrol supplementation could promote mitochondrial biosynthesis via the SIRT1/PGC-1α pathway, increase the activity of the mitochondrial energy metabolism- related enzymes, improve the antioxidant capacity of the body, and promote recover y from exercise-induced fatigue.

Establishment of Paclitaxel-resistant Breast Cancer Cell Line and Nude Mice Models, and Underlying Multidrug Resistance Mechanisms in Vitro and in Vivo

Chen, Si-Ying,Hu, Sa-Sa,Dong, Qian,Cai, Jiang-Xia,Zhang, Wei-Peng,Sun, Jin-Yao,Wang, Tao-Tao,Xie, Jiao,He, Hai-Rong,Xing, Jian-Feng,Lu, Jun,Dong, Ya-Lin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

Background: Breast cancer is a common malignant tumor which affects health of women and multidrug resistance (MDR) is one of the main factors leading to failure of chemotherapy. This study was conducted to establish paclitaxel-resistant breast cancer cell line and nude mice models to explore underlying mechanisms of MDR. Methods: The breast cancer drug-sensitive cell line MCF-7 (MCF-7/S) was exposed in stepwise escalating paclitaxel (TAX) to induce a resistant cell line MCF-7/TAX. Cell sensitivity to drugs and growth curves were measured by MTT assay. Changes of cell morphology and ultrastructure were examined by optical and electron microscopy. The cell cycle distribution was determined by flow cytometry. Furthermore, expression of proteins related to breast cancer occurrence and MDR was tested by immunocytochemistry. In Vivo, nude mice were injected with MCF-7/S and MCF-7/TAX cells and weights and tumor sizes were observed after paclitaxel treatment. In addition, proteins involved breast cancer and MDR were detected by immunohistochemistry. Results: Compared to MCF-7/S, MCF-7/TAX cells had a higher resistance to paclitaxel, cross-resistance and prolonged doubling time. Moreover, MCF-7/TAX showed obvious alterations of ultrastructure. Estrogen receptor (ER) expression was low in drug resistant cells and tumors while expression of human epidermal growth factor receptor 2 (HER2) and Ki-67 was up-regulated. P-glycoprotein (P-gp), lung resistance-related protein (LRP) and glutathione-S-transferase-${\pi}$ (GST-${\pi}$) involved in the MDR phenotype of resistant cells and tumors were all overexpressed. Conclusion: The underlying MDR mechanism of breast cancer may involve increased expression of P-gp, LRP and GST-${\pi}$.

Pig Large tumor suppressor2 (Lats2), a novel gene that may regulate the fat reduction in adipocyte

( Qiu Yue Liu ),( Xiao Rong Gu ),( Yi Qiang Zhao ),( Jin Zhang ),( Yao Feng Zhao ),( Qing Yong Meng ),( Guo Heng Xu ),( Xiao Xiang Hu ),( Ning Li ) 생화학분자생물학회 2010 BMB Reports Vol.43 No.2