Cationic surface modification of cellulose nanocrystals: Toward tailoring dispersion and interface in carboxymethyl cellulose films

Li, Mei-Chun,Mei, Changtong,Xu, Xinwu,Lee, Sunyoung,Wu, Qinglin Elsevier 2016 Polymer Vol.107 No.-

<P><B>Abstract</B></P> <P>The present work describes the development of high performance cellulose nanocrystals/carboxymethyl cellulose (CNC/CMC) films through a rational design of CNC surface chemistry. Considering the anionic surface nature of CMC, surface cationization of CNCs was performed in order to build strong interfacial bonding by electrostatic attraction and form uniform dispersion state by electrostatic repulsion. Nanocomposite films were fabricated by dispersing the CNCs and cationically modified CNCs (mCNCs) in CMC matrix through solution casting. The resultant CNC/CMC and mCNC/CMC films were then evaluated in terms of processability, mechanical properties and fracture surface morphology. Results showed that the reinforcing capacity of mCNCs was greatly dependent on its substitution degree. High substitution degree was favorable for obtaining mCNC/CMC film with uniform dispersion and superior mechanical properties. The observed distinctive reinforcing phenomena from CNCs and mCNCs in CMC matrix were interpreted in terms of dispersion state and interfacial bonding based on the fracture surface morphology.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cationic cellulose nanocrystals (CNCs) are synthesized through etherification. </LI> <LI> Substitution degree (DS) is tuned by controlling water content in reaction system. </LI> <LI> Cationic CNCs are firstly used to reinforce carboxymethyl cellulose (CMC) films. </LI> <LI> The DS of cationic CNCs plays critical role on their dispersion in CMC films. </LI> <LI> Superior reinforcement of CMC films is achieved using cationic CNCs with higher DS. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

KLF4 suppresses the tumor activity of cutaneous squamous cell carcinoma (SCC) cells via the regulation of SMAD signaling and SOX2 expression

Li, Xue Mei,Kim, Soo Jung,Hong, Dong-Kyun,Jung, Kyoung Eun,Choi, Chong Won,Seo, Young-Joon,Lee, Jeung-Hoon,Lee, Young,Kim, Chang-Deok Elsevier 2019 Biochemical and biophysical research communication Vol.516 No.4

<P><B>Abstract</B></P> <P>Kruppel-like factor 4 (KLF4) is a zinc-finger transcription factor that plays a role in terminal differentiation of epidermal keratinocytes. There are conflicting reports regarding the role of KLF4 in tumor development, with both the tumor suppressive and/or oncogenic properties depending on different conditions and cell types. In this study, we investigated the functional importance of KLF4 in cutaneous squamous cell carcinoma (SCC). Immunohistochemistry showed that KLF4 expression was relatively low in SCC lesion compared to normal epidermis. To examine the effects of KFL4, we transduced SCC lines (SCC12 and SCC13 cells) with the KLF4-expressing recombinant adenovirus. Overexpression of KLF4 significantly decreased cell proliferation and colony forming activity. In addition, overexpression of KLF4 markedly reduced invasive potential, along with the downregulation of epithelial-mesenchymal transition (EMT)-related molecules. In a mechanistic study, KLF4 inhibited SOX2, of which expression is critical for tumor initiation and growth of SCC. Further investigations indicated that SOX2 expression is induced by TGF-β/SMAD signaling, and that overexpression of KLF4 inhibited SMAD signaling via upregulation of SMAD7, an important inhibitory SMAD molecule. Based on these data, KLF4 plays a tumor suppressive role in cutaneous SCC cells.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Overexpression of KLF4 decreased the cell proliferation, colony forming activity, invasion and EMT potential in cutaneous SCC cells. </LI> <LI> Overexpression of KLF4 decreased SOX2 level via inhibition of SMAD2 phosphorylation. </LI> <LI> Overexpression of KLF4 inhibited SMAD signaling via upregualtion of SMAD7, an inhibitory SMAD molecule. </LI> </UL> </P>

Colorectal Cancer Concealment Predicts a Poor Survival: A Retrospective Study

Li, Xiao-Pan,Xie, Zhen-Yu,Fu, Yi-Fei,Yang, Chen,Hao, Li-Peng,Yang, Li-Ming,Zhang, Mei-Yu,Li, Xiao-Li,Feng, Li-Li,Yan, Bei,Sun, Qiao Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.7

Objectives: Understanding the situation of cancer awareness which doctors give to patients might lead to prognostic prediction in cases of of colorectal cancer (CRC). Methods: Subsets of 10,779 CRC patients were used to screen the risk factors from the Cancer Registry in Pudong New Area in cancer awareness, age, TNM stage, and gender. Survival of the patients was calculated by the Kaplan-Meier method and assessed by Cox regression analysis. The views of cancer awareness in doctors and patients were surveyed by telephone or household. Results: After a median observation time of 1,616 days (ranging from 0 to 4,083 days) of 10,779 available patients, 2,596 of the 4,561 patients with cancer awareness survived, whereas 2,258 of the 5,469 patients without cancer awareness and 406 of the 749 patients without information on cancer awareness died of the disease. All-cause and cancer-specific survival were poorer for the patients without cancer awareness than those with (P < 0.001 for each, log-rank test). Cox multivariate regression analysis showed that cancer concealment cases had significantly lower cancer-specific survival (hazard ratio (HR) = 1.299; 95 % confidence interval (CI): 1.200-1.407)and all-cause survival (HR = 1.324; 95 % CI: 1.227-1.428). Furthermore, attitudes of cancer awareness between doctors and patients were significantly different (P < 0.001). Conclusion: Cancer concealment, not only late-stage tumor and age, is associated with a poor survival of CRC patients.

T-SPOT.TB for Detection of Tuberculosis Infection among Hematological Malignancy Patients and Hematopoietic Stem Cell Transplant Recipients

Qin, Li-Li,Wang, Qin-Rong,Wang, Qian,Yao, Hong,Wen, Li-Jun,Wu, Li-Li,Ping, Na-Na,Xie, Jun-Dan,Chen, Mei-Yu,Chen, Su-Ning Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

The diagnosis of latent Mycobacterium tuberculosis infection (LTBI) is recommended in hematological malignancy patients and before hematopoietic stem cell transplantation (Guidelines for the prevention and management of infectious complications of solid organ transplantation, 2004). Compared to traditional methods such as tuberculin skin test (TST), T-SPOT.TB has been shown to be more specific. In the present study we enrolled 536 patients for whom T-SPOT.TB was performed, among which 295 patients also received the TST test. The agreement (79%) between T-SPOT.TB and TST was poor (x=0.274, P<0.001). The patients with positive T-SPOT.TB results numbered 62 (11.6%), in which only 20 (48.8%) of the 41 receiving the TST test had positive results. A majority of the patients with T-SPOT.TB positive results had some other evidence ofTB, such as TB history, clinical symptoms and an abnormal chest CT scan. Active TB was found in 9 patients, in which 2 had negative TST results. We followed up the patients and no one developed active TB. Our study suggested that the T-SPOT.TB may be more useful for screening LTBI and active TB in hematological malignancy patients and hematopoietic stem cell transplant recipients than the TST test.

Dietary exposure and human risk assessment of phthalate esters based on total diet study in Cambodia

Cheng, Zhang,Li, Han-Han,Wang, Hong-sheng,Zhu, Xue-Mei,Sthiannopkao, Suthipong,Kim, Kyoung-Woong,Yasin, Mohamed Salleh Mohamed,Hashim, Jamal Hisham,Wong, Ming-Hung Elsevier 2016 Environmental research Vol.150 No.-

<P><B>Abstract</B></P> <P>Phthalate esters are used in a wide variety of consumer products, and human exposure to this class of compounds is widespread. Nevertheless, studies on dietary exposure of human to phthalates are limited. In this study, to assess the daily intakes of phthalate esters and the possible adverse health impacts, different food samples were collected from three areas of Cambodia, one of the poorest countries in the world. The ∑phthalate ester concentrations in Kampong Cham, Kratie and Kandal provinces ranged from 0.05 to 2.34 (median 0.88) μgg<SUP>−1</SUP>, 0.19–1.65 (median 0.86) μgg<SUP>−1</SUP> and 0.24–3.05 (median 0.59) μgg<SUP>−1</SUP> wet weight (ww), respectively. Di-2-Ethylhexyl phthalate (DEHP) and diisobutyl phthalate (DiBP) were the predominant compounds among all foodstuffs. The estimated daily intake (EDI) of phthalate esters for the general population in Kampong Cham, Kratie and Kandal was 34.3, 35.6 and 35.8μgkg<SUP>−1</SUP> bw d<SUP>−1</SUP>, respectively. The dietary daily intake of DEHP, benzylbutyl phthalate (BBP) and di-n-butyl phthalate (DBP) in Kampong Cham, Kratie and Kandal were below the tolerable daily intakes (TDI) imposed by the European Food Safety Authority (EFSA) and reference doses (RfD) imposed by The United States Environmental Protection Agency (USEPA). Rice contributed the greatest quantity of DEHP to the daily intake in Cambodia so may deserve further exploration. To our knowledge, this is the first study to investigate the occurrence and the daily intakes of phthalate esters in Cambodia.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Phthalate esters concentration in daily foodstuffs collected from Cambodia. </LI> <LI> Investigate the bioaccessbility of phthalate esters via the foodstuffs consumption. </LI> <LI> Health risk evaluation of dietary exposure to phthalate esters. </LI> </UL> </P>

The F-box Protein KIB1 Mediates Brassinosteroid-Induced Inactivation and Degradation of GSK3-like Kinases in <i>Arabidopsis</i>

Zhu, Jia-Ying,Li, Yuyao,Cao, Dong-Mei,Yang, Hongjuan,Oh, Eunkyoo,Bi, Yang,Zhu, Shengwei,Wang, Zhi-Yong Elsevier 2017 Molecular cell Vol.66 No.5

<P><B>Summary</B></P> <P>The glycogen synthase kinase-3 (GSK3) family kinases are central cellular regulators highly conserved in all eukaryotes. In <I>Arabidopsis</I>, the GSK3-like kinase BIN2 phosphorylates a range of proteins to control broad developmental processes, and BIN2 is degraded through unknown mechanism upon receptor kinase-mediated brassinosteroid (BR) signaling. Here we identify KIB1 as an F-box E3 ubiquitin ligase that promotes the degradation of BIN2 while blocking its substrate access. Loss-of-function mutations of KIB1 and its homologs abolished BR-induced BIN2 degradation and caused severe BR-insensitive phenotypes. KIB1 directly interacted with BIN2 in a BR-dependent manner and promoted BIN2 ubiquitination in vitro. Expression of an F-box-truncated KIB1 caused BIN2 accumulation but dephosphorylation of its substrate BZR1 and activation of BR responses because KIB1 blocked BIN2 binding to BZR1. Our study demonstrates that KIB1 plays an essential role in BR signaling by inhibiting BIN2 through dual mechanisms of blocking substrate access and promoting degradation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> KIB1 is an essential positive regulator in brassinosteroid signaling </LI> <LI> KIB1 mediates BR-induced ubiquitination and degradation of GSK3 kinase BIN2 </LI> <LI> KIB1 binding to BIN2 prevents BIN2-substrate interaction and promotes BIN2 degradation </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

Properties of Monte Carlo and Its Application to Risk Management

Li Rui-mei 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.9

The complexity and turbulence of a project may lead to its unpredictability, so risk management is increasingly important. This paper focuses on the application of Monte Carlo method in project management as follow: first, deals with the estimated scale with Wide band Delphi method and gets the interval of prediction after making repeated samples in line with the generally adopted probability models; then figures out the workloads according to the management abilities and historical date; finally obtains the progress of the project with a method combining COCOMOⅡ method and then improves the ability to predict and control management activities with uncertainties.

Emulsion Grafting Vinyl Monomers onto Starch for Reinforcement of Styrene-Butadiene Rubber

Mei-Chun Li,Xin Ge,조을룡 한국고분자학회 2013 Macromolecular Research Vol.21 No.5

Three types of modified starches (MST): Starch-g-poly(butyl acrylate) (ST-g-PBA), starch-g-poly (methyl methacrylate) (ST-g-PMMA) and starch-g-polystyrene (ST-g-PS) latexes were successfully synthesized by emulsion polymerization. These synthesized MST latexes were then directly compounded with styrene-butadiene rubber (SBR) latex in order to prepare MST/SBR compounds. The vulcanization characteristics, morphology, swelling ratio, mechanical and dynamic mechanical properties were investigated. Results indicated that the incorporation of starch or MST led to both an increase in the torque values and the cure rate of SBR compounds. MST with a particle size of approximately 200-400 nm uniformly dispersed in the SBR matrix, indicating the significantly improved dispersion. MST/SBR compounds exhibited better mechanical properties compared with starch/SBR (ST/SBR)compounds. Among the MST/SBR compounds, ST-g-PMMA/SBR compounds showed optimum tensile strength,which was even higher than that of carbon black/SBR (CB/SBR) compounds with the same loading of fillers. Finally, the reinforcing mechanism of MST in the SBR matrix was discussed.

Cellulose Nanocrystals and Polyanionic Cellulose as Additives in Bentonite Water-Based Drilling Fluids: Rheological Modeling and Filtration Mechanisms

Li, Mei-Chun,Wu, Qinglin,Song, Kunlin,De Hoop, Corneils F.,Lee, Sunyoung,Qing, Yan,Wu, Yiqiang American Chemical Society 2016 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.55 No.1

<P>This research aims to develop low cost, sustainable, environmentally friendly, and high performance water-based drilling fluids (WDFs) using bentonite (BT), polyanionic cellulose (PAC), and cellulose nanocrystals (CNCs). The effect of concentration of BT, PAC, and CNCs on the rheological and filtration properties of PAC/CNC/BT-WDFs was investigated. Eight empirical rheological models were applied to fit quantitatively the fluid properties. Results showed that the presence of PAC, CNCs, and BT improved the rheological and filtration properties of the WDFs. Among the eight empirical rheological models, the Sisko model performed the best in simulating the rheological behavior of the fluids. At the same concentration level of PAC and CNCs, CNCs had more impact on the rheological properties, whereas PAC had more influence on the filtration property. The incorporation of PAC resulted in very low permeable filter cakes, leading to the excellent filtration property. The combined use of PAC and CNCs yielded better rheological and filtration properties.</P>

Insulin Resistance Reduces Sensitivity to Cis-Platinum and Promotes Adhesion, Migration and Invasion in HepG2 Cells

Li, Lin-Jing,Li, Guang-Di,Wei, Hu-Lai,Chen, Jing,Liu, Yu-Mei,Li, Fei,Xie, Bei,Wang, Bei,Li, Cai-Li Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.7

The liver is normally the major site of glucose metabolism in intact organisms and the most important target organ for the action of insulin. It has been widely accepted that insulin resistance (IR) is closely associated with postoperative recurrence of hepatocellular carcinoma (HCC). However, the relationship between IR and drug resistance in liver cancer cells is unclear. In the present study, IR was induced in HepG2 cells via incubation with a high concentration of insulin. Once the insulin-resistant cell line was established, the stability of HepG2/IR cells was further tested via incubation in insulin-free medium for another 72h. Afterwards, the biological effects of insulin resistance on adhesion, migration, invasion and sensitivity to cis-platinum (DDP) of cells were determined. The results indicated that glucose consumption was reduced in insulin-resistant cells. In addition, the expression of the insulin receptor and glucose transportor-2 was downregulated. Furthermore, HepG2/IR cells displayed markedly enhanced adhesion, migration, and invasion. Most importantly, these cells exhibited a lower sensitivity to DDP. By contrast, HepG2/IR cells exhibited decreased adhesion and invasion after treatment with the insulin sensitizer pioglitazone hydrochloride. The results suggest that IR is closely related to drug resistance as well as adhesion, migration, and invasion in HepG2 cells. These findings may help explain the clinical observation of limited efficacy for chemotherapy on a background of IR, which promotes the invasion and migration of cancer cells.