Preparation, Characterization and Properties of Poly(lactic acid)/ Poly(1,4-butylene adipate) Blends for Biodegradable Packaging Materials

Zhimeng Liu,Yuan Lei,Zeyu Hu,Weibo Kong,Changlin Zhou,Jingxin Lei 한국고분자학회 2017 Macromolecular Research Vol.25 No.5

Poly(lactic acid) (PLA)/poly(1,4-butylene adipate) (PBA) blends with different PBA content were directly prepared via melt blending as potential biodegradable packaging materials. PBA with 1000 g/mol number average molecular weight was served as plasticizer to improve PLA properties. The morphological, thermal and mechanical properties of the blends were extensively investigated by scanning electron microscope (SEM), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), tensile and impact tests and thermogravimetry (TG). The results show that the degree of crystallinity of PLA increased with increasing PBA content. The addition of PBA (20 wt%) result in the positive effect on the elongation at break and toughness, which increased from 7.9% to 74.4% and from 3.9 kJ/m2 to 12.6 kJ/ m2, respectively. Meanwhile, the migration tests indicate that PBA exhibits excellent lower migration ratio compared with citrate esters.

Potent antibacterial and antibiofilm activities of TICbf-14, a peptide with increased stability against trypsin

Wang Liping,Liu Xiaoyun,Ye Xinyue,Zhou Chenyu,Zhao Wenxuan,Zhou Changlin,Ma Lingman 한국미생물학회 2022 The journal of microbiology Vol.60 No.1

The poor stability of peptides against trypsin largely limits their development as potential antibacterial agents. Here, to obtain a peptide with increased trypsin stability and potent antibacterial activity, TICbf-14 derived from the cationic peptide Cbf-14 was designed by the addition of disulfide-bridged hendecapeptide (CWTKSIPPKPC) loop. Subsequently, the trypsin stability and antimicrobial and antibiofilm activities of this peptide were evaluated. The possible mechanisms underlying its mode of action were also clarified. The results showed that TICbf-14 exhibited elevated trypsin inhibitory activity and effectively mitigated lung histopathological damage in bacteria-infected mice by reducing the bacterial counts, further inhibiting the systemic dissemination of bacteria and host inflammation. Additionally, TICbf-14 significantly repressed bacterial swimming motility and notably inhibited biofilm formation. Considering the mode of action, we observed that TICbf-14 exhibited a potent membrane-disruptive mechanism, which was attributable to its destructive effect on ionic bridges between divalent cations and LPS of the bacterial membrane. Overall, TICbf-14, a bifunctional peptide with both antimicrobial and trypsin inhibitory activity, is highly likely to become an ideal candidate for drug development against bacteria.

Transcriptome analysis of gene expression patterns during embryonic development in golden cuttlefish (Sepia esculenta)

Li Bian,Changlin Liu,Siqing Chen,Fazhen Zhao,Jianlong Ge,Jie Tan 한국유전학회 2018 Genes & Genomics Vol.40 No.3

Golden cuttlefish (Sepia esculenta) is an important economic species in China. Because of the rapid decline of its natural resource, researchers are exploring breeding technique for this species. The major obstacle that hinders artificial breeding of S. esculenta is the low larvae survival rate. Mortality is especially high during the mouth-opening stage. Investigating the embryogenesis before the first feed could provide theoretical guidance for reproduction control and breeding of S. esculenta and other Sepia species. In this study, we analyzed the dynamics of the S. esculenta transcriptome along different stages of embryonic development by mRNA-sEq. Our bioinformatics protocol identified 1492 differentially expressed genes (DEGs) across the early developmental stages. Gene ontology enrichment analysis showed that the DEGs were significantly involved in developmental processes and molecular functions, including chitin metabolic process, peptidase activity, catalytic activity, and calcium ion binding. Our results indicated that genes related to cuttlebone development and gene regulation functions were active during the early life phase of S. esculenta. Hierarchical clustering of the DEGs reflected the successiveness of the developmental stages, revealing that gene expression patterns of neighboring stages were similar. The DEG analysis allowed us to identify specific genes and relevant biological pathways to better understand the molecular mechanisms during each developmental stage. This study provides novel insights into the processes underlying the early developmental stages of S. esculenta. The transcriptomic data and identified genes will serve as valuable references for the developmental biology of this species and will help promote its aquaculture research.

Characterization of the global transcriptome and microsatellite marker information for spotted halibut Verasper variegatus

Jianlong Ge,Siqing Chen,Changlin Liu,Li Bian,Huiling Sun,Jie Tan 한국유전학회 2017 Genes & Genomics Vol.39 No.3

The spotted halibut Verasper variegatus is an economically important flatfish species distributed in Japan, Korea and China. However, the genomic resources regarding this species were scarcity, which hindered our understanding of the genetics and biological mechanisms in spotted halibut. In this study, we examined the global transcriptome from six major tissues of spotted halibut. Approximately 40 million of high quality reads were generated using Illumina paired-end sequencing technology. More than 9 Gbp data were generated, and de novo assembled into 59,235 unigenes, with an N50 of 938 bp. Based on sequence similarity search with known protein database, 34,084 (57.5%) showed significant similarity to known proteins in Nr database, and 28,875 (48.7%) had BLAST hits in Swiss-Prot database. 19,562 and 23,037 unigenes were assigned into gene ontology categories and clusters of orthologous group, respectively. 9138 unigenes were mapped to 211 KEGG pathways. For functional marker development, 13,322 candidate simple sequence repeats were identified in the transcriptome and 7235 primer pairs were successfully designed. Among 72 primer pairs selected for validation, 67 (93.1%) were successful in PCR amplification and 14 (19.4%) exhibited obvious repeat length polymorphisms in a culture spotted halibut population. The transcriptomic data and microsatellite markers will provide valuable resources for future functional gene analyses, genetic map construction, and quantitative trait loci mapping in V. variegatus.

RHIZOMUCOR MIEHEI LIPASE: GENE CLONING, EXPRESSION IN PICHIA PASTORIS AND PROPERTIES

LUO Wen,MIAO Changlin,LU Pengmei,LIU Shuna,Yuan zhenhong 한국신재생에너지학회 2012 AFORE Vol.2012 No.-

A Study on Construction and Simulation of Agricultural Machinery System Control Model

Wang Ying,Xu Shiyang,Liu Shiqiang,Li Xiaoxue,Ao Changlin 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.8

In order to study the state-changing and running rules of agricultural machinery system, this paper establishes the control model of agricultural machinery system under the discrete-state space based on control theory, from the perspective of the complex systems and with reference to the actual conditions of agricultural production; conducts the qualitative analysis on the system model, builds the relevant simulation model of agricultural machinery system accordingly, and verifies the running of the simulation model. This control model can provide effective basis and reference for further quantitative studies on state evolution of agricultural machinery system.

The antimicrobial activity of Cbf-K16 against MRSA was enhanced by β-lactamantibiotics through cell wall non-integrity

Bo Li,Wei Kang,Hanhan Liu,Yanrong Wang,Changzhong Yu,Xinyi Zhu,Jie Dou,Haibo Cai,Changlin Zhou 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.7

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as one of the most important pathogens both in health care and in community-onset infections. Cbf-K16, a cathelicidin-like antimicrobial peptide, presented broad antimicrobial activity during our previous studies. We evaluated the potential for synergy of Cbf-K16 with ceftazidime/ampicilin against MRSA, which was resistant to these two antibiotics with the minimum inhibitory concentration more than 64 μg/ml. The combinations showed a synergistic effect by a checkerboard assay with a fractional inhibitory concentration index ≤0.5. The killing curves of the combination treatment against MRSA showed that CFU counts decreased rapidly within 4 h by almost five logs, while single medication groups and the control group exhibited little inhibitory effect. In addition, in a mice bacteremia model, studies indicated that the combination treatment significantly prolonged the survival time of mice infected with MRSA, with a death protection rate of 80 %. Flow cytometry analysis and transmission electron microscopy indicated that combination- treated MRSA was completely ruptured with the cellular contents leaked out. The synergistic effect showed that Cbf-K16 selectively killed cells with non-integrity induced by cell wall inhibition antibiotics, suggesting that Cbf-K16 is a potential therapeutic agent and adjuvant for antimicrobial chemotherapy.

Dynamic changes in carbohydrate metabolism and endogenous hormones during Tulipa edulis stolon development into a new bulb

Yuanyuan Miao,Zaibiao Zhu,Qiaosheng Guo,Xiaohua Yang,Li Liu,Yuan Sun,Changlin Wang 한국식물학회 2016 Journal of Plant Biology Vol.59 No.2

The stolon is the main asexual reproductive organ of Tulipa edulis (Miq.) Baker. It has a special morphology and can develop into a new bulb for propagation. In the current greenhouse experiment, the dynamic changes in carbohydrates and related enzymes, protein and endogenous hormones during T. edulis stolon development were investigated. The results showed that soluble sugar levels were basically declining, whereas starch and protein content rose continuously during stolon development. The adenosine diphosphoglucose pyrophosphorylase (AGPase) activity peaked in the initial swelling stage and stayed a relative high level in the middle swelling stage; sucrose synthase (SS), soluble starch synthase (SSS) and granule-bound starch synthase (GBSS) activities followed the same law that showed rising trends during stolon development. SS activity was significantly inversely related to sucrose content but had significantly positive relations with starch content, SSS and GBSS activities. Gibberellin (GA), indole-3-acetic acid (IAA) and zeatin riboside (ZR) peaked in the initial swelling stage and maintained high levels in the middle swelling stage; they then decreased significantly in the later swelling stage. A substantial increase was observed in abscisic acid (ABA) content until the middle swelling stage, followed by a significant reduction in the later swelling stage. The ratios of ABA to IAA, GA and ZR reached their lowest levels in the initial swelling stage. In conclusion, T. edulis stolon development is a process of new bulb morphogenesis along with the starch accumulation catalyzed by AGPase, SSS and GBSS, using the product of sucrose cleavage caused by SS. Initial low ABA content and low ratios of ABA to IAA, GA and ZR, together with the GA, IAA and ZR of high-content, soluble sugars worked more efficiently to induce new bulb formation.

ASSESSMENT OF STOCK ENHANCEMENT PROGRAM IN Sepia.esculenta BY USING MICROSATELLITE TAGGING

Pengwei Ding,Na Song,Tianxiang Gao,Siqing Chen,Xiumei Zhang,Changlin Liu 한국수산과학회 양식분과 2015 한국수산과학회 양식분과 학술대회 Vol.2015 No.5

Setup and Performance of a Combined Hardware-in-loop and Software-in-loop Test for MMC-HVDC Control and Protection System

Chang Lin,Dong Liu,Xueguang Wu,ZhiyuanHe,Weihua Wang,Wei Li 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Despite the rapid development of VSC-HVDC technology, the practical experience to operate modular multi-level converter (MMC) has not yet been sufficiently accumulated. Real-time simulation is one of the most efficient approaches to verify the control and protection (C & P) scheme under various contingencies. With the increasing number of sub-modules, the accurate simulation of the MMC-HVDC becomes more difficult, as it requires larger computing resources and more complex interface between the test platform and the C&P system hardware devices. This paper proposes an application of real-time simulation, which combines the hardware-in--loop (HIL) and software-in-loop (SIL) approach to test a control and protection system for MMC-based HVDC links. In the proposed system, a pole control and protection (PCP) will be tested using the HIL approach, while the valve base controller (VBC) is tested using the SIL method. The setup of the test rig and performance is demonstrated in this paper.