Carbon-coated SnO₂@C with hierarchically porous structures and graphite layers inside for a high-performance lithium-ion battery

Li, Yao,Zhu, Shenmin,Liu, Qinglei,Gu, Jiajun,Guo, Zaiping,Chen, Zhixin,Feng, Chuanliang,Zhang, Di,Moon, Won-Jin The Royal Society of Chemistry 2012 Journal of materials chemistry Vol.22 No.6

<P>A high-performance anode material was prepared from a hierarchically structured activated carbon which contains <I>in situ</I> graphene and nano-graphite. The activated carbon was immersed in a solution of SnCl<SUB>2</SUB>·2H<SUB>2</SUB>O and subjected to ultrasound. As a result, nanoparticles of SnO<SUB>2</SUB> were uniformly deposited on the surface of the activated carbon. The composite material was then coated with a thin layer of carbon by soaking it in a sucrose solution, followed by carbonization of the adsorbed sucrose at 500 °C. The resulting composite showed an outstanding high-rate cycling performance that can deliver an initial discharge capacity of 1417 mAh g<SUP>−1</SUP> and maintain a discharge capacity of more than 400 mAh g<SUP>−1</SUP> after 100 cycles at a high current density of 1000 mA g<SUP>−1</SUP>. This outstanding electrochemical performance is likely to be related to a unique combination of the excellent electrical conductivity of the activated carbon with graphite layers formed inside, its hierarchical pore structure which enhances lithium-ion transportation, and the carbon coating which alleviates the effects of volume changes, shortens the distance for Li<SUP>+</SUP> diffusion, facilitates the transmission of electrons, and keeps the structure stable.</P> <P>Graphic Abstract</P><P>Carbon-coated SnO<SUB>2</SUB>@C nanocomposite with hierarchically porous structures and graphite layers inside was prepared by ultrasound and hydrothermal treatment, which showed an outstanding high-rate cycling performance for lithium-ion battery. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1jm14290a'> </P>

A large-area free-standing graphene oxide multilayer membrane with high stability for nanofiltration applications

Chen, Long,Li, Yanhui,Chen, Lina,Li, Na,Dong, Chenglong,Chen, Qiong,Liu, Beibei,Ai, Qing,Si, Pengchao,Feng, Jinkui,Zhang, Lin,Suhr, Jonghwan,Lou, Jun,Ci, Lijie Elsevier 2018 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.345 No.-

<P><B>Abstract</B></P> <P>A flexible and free-standing graphene oxide and nylon 6 (GO@nylon 6) multilayer nanofiltration membrane was prepared by a layer-by-layer assembly process. The combination of electrospinning and electrospraying technique was employed, which can facilely prepare large-area membrane with size of 20 × 30 cm. The mechanical stability of multilayer membrane has enhanced significantly due to the tightly locked structure achieved by nylon 6 nanofibers network. The novel GO@nylon 6–13 multilayer nanofiltration membrane demonstrated a pure water flux up to 11.15 L m<SUP>−2</SUP> h<SUP>−1</SUP> bar<SUP>−1</SUP>, while keeping high organic dye rejection rate (>95% for methylene blue, and >99% for methyl orange). The rejections rate of the Na<SUB>2</SUB>SO<SUB>4</SUB>, NaCl, CuSO<SUB>4</SUB>, and Pb(NO<SUB>3</SUB>)<SUB>2</SUB> were 56.5%, 27.6%, 36.7%, and 18.9%, respectively. Furthermore, GO@nylon 6–13 multilayer nanofiltration membrane also demonstrated a high flux of some common organic solvents (8.4, 5.3, and 0.8 L m<SUP>−2</SUP> h<SUP>−1</SUP> bar<SUP>−1</SUP> for methanol, ethanol, and NMP, respectively), showing excellent chemical stability for separation process in those solvents.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Large-area GO@nylon 6 multilayer nanofiltration membrane was prepared. </LI> <LI> The multilayer structure enhances the mechanical stability. </LI> <LI> The multilayer membrane demonstrates a high water flux. </LI> <LI> The multilayer membrane shows high rejection rate for organic dyes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Photograph and cross-section SEM image of GO@nylon 6 multilayer nanofiltration membrane, the inset shows the water contact angle.</P> <P>[DISPLAY OMISSION]</P>

Potential impact of flowback water from hydraulic fracturing on agricultural soil quality: Metal/metalloid bioaccessibility, Microtox bioassay, and enzyme activities

Chen, Season S.,Sun, Yuqing,Tsang, Daniel C.W.,Graham, Nigel J.D.,Ok, Yong Sik,Feng, Yujie,Li, Xiang-Dong Elsevier 2017 The Science of the total environment Vol.579 No.-

<P><B>Abstract</B></P> <P>Hydraulic fracturing has advanced the development of shale gas extraction, while inadvertent spills of flowback water may pose a risk to the surrounding environment due to its high salt content, metals/metalloids (As, Se, Fe and Sr), and organic additives. This study investigated the potential impact of flowback water on four representative soils from shale gas regions in Northeast China using synthetic flowback solutions. The compositions of the solutions were representative of flowback water arising at different stages after fracturing well establishment. The effects of solution composition of flowback water on soil ecosystem were assessed in terms of metal mobility and bioaccessibility, as well as biological endpoints using Microtox bioassay (<I>Vibrio fischeri</I>) and enzyme activity tests. After one-month artificial aging of the soils with various flowback solutions, the mobility and bioaccessibility of As(V) and Se(VI) decreased as the ionic strength of the flowback solutions increased. The results inferred a stronger binding affinity of As(V) and Se(VI) with the soils. Nevertheless, the soil toxicity to <I>Vibrio fischeri</I> only presented a moderate increase after aging, while dehydrogenase and phosphomonoesterase activities were significantly suppressed with increasing ionic strength of flowback solutions. On the contrary, polyacrylamide in the flowback solutions led to higher dehydrogenase activity. These results indicated that soil enzyme activities were sensitive to the composition of flowback solutions. A preliminary human health risk assessment related to As(V) suggested a low level of cancer risk through exposure via ingestion, while holistic assessment of environmental implications is required.</P> <P><B>Highlights</B></P> <P> <UL> <LI> High ionic strength of flowback water reduced mobility of metalloids. </LI> <LI> Relatively high bioaccessibility of metalloids in spite of low mobility </LI> <LI> Soil toxicity moderately increased after 1-month aging with flowback water. </LI> <LI> Soil dehydrogenase activity was affected by PAM in flowback water. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Insights into the subsurface transport of As(V) and Se(VI) in produced water from hydraulic fracturing using soil samples from Qingshankou Formation, Songliao Basin, China

Chen, Season S.,Sun, Yuqing,Tsang, Daniel C.W.,Graham, Nigel J.D.,Ok, Yong Sik,Feng, Yujie,Li, Xiang-Dong Elsevier 2017 Environmental pollution Vol.223 No.-

<P><B>Abstract</B></P> <P>Produced water is a type of wastewater generated from hydraulic fracturing, which may pose a risk to the environment and humans due to its high ionic strength and the presence of elevated concentrations of metals/metalloids that exceed maximum contamination levels. The mobilization of As(V) and Se(VI) in produced water and selected soils from Qingshankou Formation in the Songliao Basin in China were investigated using column experiments and synthetic produced water whose quality was representative of waters arising at different times after well creation. Temporal effects of produced water on metal/metalloid transport and sorption/desorption were investigated by using HYDRUS-1D transport modelling. Rapid breakthrough and long tailings of As(V) and Se(VI) transport were observed in Day 1 and Day 14 solutions, but were reduced in Day 90 solution probably due to the elevated ionic strength. The influence of produced water on the hydrogeological conditions (i.e., change between equilibrium and non-equilibrium transport) was evidenced by the change of tracer breakthrough curves before and after the leaching of produced water. This possibly resulted from the sorption of polyacrylamide (PAM (-CH<SUB>2</SUB>CHCONH<SUB>2</SUB>-)<SUB>n</SUB>) onto soil surfaces, through its use as a friction reducer in fracturing solutions. The sorption was found to be reversible in this study. Minimal amounts of sorbed As(V) were desorbed whereas the majority of sorbed Se(VI) was readily leached out, to an extent which varied with the composition of the produced water. These results showed that the mobilization of As(V) and Se(VI) in soil largely depended on the solution pH and ionic strength. Understanding the differences in metal/metalloid transport in produced water is important for proper risk management.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Earlier breakthrough of metals with increasing ionic strength of flowback solutions. </LI> <LI> Two-region physical non-equilibrium model provided a good fit of metal transport. </LI> <LI> Less non-equilibrium transport in Day 14 and Day 90 than Day 1 flowback solutions. </LI> <LI> Tracer tests indicated reversible change of transport channels due to leaching. </LI> <LI> Sorption/desorption of As(V) and Se(VI) was both pH- and ionic strength-dependent. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Zero-valent iron for the abatement of arsenate and selenate from flowback water of hydraulic fracturing

Sun, Yuqing,Chen, Season S.,Tsang, Daniel C.W.,Graham, Nigel J.D.,Ok, Yong Sik,Feng, Yujie,Li, Xiang-Dong Elsevier 2017 CHEMOSPHERE - Vol.167 No.-

<P><B>Abstract</B></P> <P>Zero-valent iron (ZVI) was tested for the removal of 150 μg L<SUP>−1</SUP> As(V) and 350 μg L<SUP>−1</SUP> Se(VI) in high-salinity (ionic strength 0.35–4.10 M) flowback water of hydraulic fracturing. Over 90% As(V) and Se(VI) was removed by 2.5 g L<SUP>−1</SUP> ZVI in Day-14 flowback water up to 96-h reaction, with the remaining concentration below the maximum contaminant level for As(V) and criterion continuous concentration for Se(VI) recommended by US EPA. The kinetics of As(V) and Se(VI) removal followed a pseudo-second-order rate expression with the observed rates of 4.51 × 10<SUP>−2</SUP>–4.91 × 10<SUP>−1</SUP> and 3.48 × 10<SUP>−2</SUP>–6.58 × 10<SUP>−1</SUP> h<SUP>−1</SUP> (with 0.5–10 g L<SUP>−1</SUP> ZVI), respectively. The results showed that Se(VI) removal significantly decreased with increasing ionic strength, while As(V) removal showed little variation. Common competing anions (nitrate, bicarbonate, silicate, and phosphate), present in shallow groundwater and stormwater, caused marginal Se(VI) desorption (2.42 ± 0.13%) and undetectable As(V) desorption from ZVI. The competition between As(V) and Se(VI) for ZVI removal depended on the initial molar ratio and surface sites, which occurred when the Se(VI) concentration was higher than the As(V) concentration in this study. The characterization of As(V)- and Se(VI)-loaded ZVI by X-ray diffraction and Raman analysis revealed that ZVI gradually converted to magnetite/maghemite corrosion products with lepidocrocite in flowback water over 30 days. Similar corrosion compositions were confirmed in aerobic and anaerobic conditions regardless of the molar ratio of As(V) to Se(VI). The high reactivity and stability of ZVI showed its suitability for <I>in-situ</I> prevention of As(V) and Se(VI) migration due to accidental leakage, spillage, or overflow of flowback water.</P> <P><B>Highlights</B></P> <P> <UL> <LI> As(V) and Se(VI) in high-salinity flowback water was effectively removed by ZVI. </LI> <LI> As(V) removal was less susceptible to ionic strength variations than Se(V). </LI> <LI> Competing anions in groundwater and stormwater caused insignificant desorption. </LI> <LI> As(V) and Se(VI) competition depended on their molar ratio and ZVI surface sites. </LI> <LI> Surface characteristics of ZVI were unaffected by molar ratio and dissolved oxygen. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Analysis of Different Activation Statuses of Human Mammary Epithelial Cells from Young and Old Groups

Feng, Chen-Chen,Chen, Li-Na,Chen, Mei-Jun,Li, Wan,Jia, Xu,Zhou, Yan-Yan,He, Wei-Ming Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.8

Human mammary epithelial cells have different proliferative statuses and demonstrate a close relationship with age and cell proliferation. Research on this topic could help understand the occurrence, progression and prognosis of breast cancer. In this article, using significance analysis of a microarray algorithm, we analyzed gene expression profiles of human mammary epithelial cells of different proliferative statuses and different age groups. The results showed there were significant differences in gene expression in the same proliferation status between elderly and young groups. Three common differentially expressed genes were found to dynamically change with the proliferation status and to be closely related to tumorigenesis. We also found elderly group had less status-related differential genes from actively proliferating status to intermediate status and more statusrelated differential genes from intermediate status than the young group. Finally, functional enrichment analyses allowed evaluation of the detailed roles of these differentially-expressed genes in tumor progression.

Use of Acupressure to Improve Gastrointestinal Motility in Women after Trans-abdominal Hysterectomy

Chen, Li-Li,Hsu, Sheng-Feng,Wang, Min-Hung,Chen, Chao-Ling,Lai, Jim-Shoung 경희대학교 2001 INTERNATIONAL SYMPOSIUM ON EAST-WEST MEDICINE Vol.2001 No.1

Objective : To evaluate the effectiveness of acupressure on the gastrointestinal motility (GI) in women after trans-abdominal hysterectomy(TAH). Methods : Forty-one women undergoing trans-abdominal hysterectomy were recruited and randomly assigned to two groups. Twenty-one patients were assigned to the experimental group while remaining 20 patients were assigned as controls. A single blinded test was used for this study. Patients were not informed as to the tripe of treatment they would receive. The experimental group received twice daily acupressure for 3 minutes at three meridian points, Neiguan(PC-6), Zusanli(ST-36) and Sanyinjiao(SP-6), beginning 4 hours after surgery and continuing for 3 days. Control group received 3 minutes acupressure on non-meridian points on the tibia or radial bone surface approximately 3 to 4 cm from the corresponding three meridian points. Acupressure was performed twice a day, one at 10 Am and another at 2 Pm. GI contractions was measured by stethoscope prior to and after afternoon acupressure during 2- minute observational period. Results : Results show that acupressure of these three meridian points significantly (p<0.05) increased GI motility in the experimental groups, but not in the control group (p>0.05). Conclusions : Results showed that non-invasive acupressure of these meridian points could significantly improve the GI motility and could be incorporated into the technical curriculum and clinical education program of nursing schools. Family members of the patient could be taught to continue this procedure at home to enhance GI motility in patients undergoing trans-abdominal hysterectomy.

Clinicopathologic Characteristics and Prognoses for Multicentric Occurrence and Intrahepatic Metastasis in Synchronous Multinodular Hepatocellular Carcinoma Patients

Li, Shi-Lai,Su, Ming,Peng, Tao,Xiao, Kai-Yin,Shang, Li-Ming,Xu, Bang-Hao,Su, Zhi-Xiong,Ye, Xin-Ping,Peng, Ning,Qin, Quan-Lin,Chen, De-Feng,Chen, Jie,Li, Le-Qun Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.1

Background: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and the outcomes for patients are still poor. It is important to determine the original type of synchronous multinodular HCC for preoperative assessment and the choice of treatment therapy as well as for the prediction of prognosis after treatment. Aims: To analyze clinicopathologic characteristics and prognoses in patients with multicentric occurrence (MO) and intrahepatic metastasis (IM) of synchronous multinodular hepatocellular carcinoma (HCC). Methods: The study group comprised 42 multinodular HCC patients with a total of 112 nodules. The control group comprised 20 HCC patients with 16 single nodular HCC cases and 4 HCC cases with a portal vein tumor emboli. The mitochondrial DNA (mtDNA) D-loop region was sequenced, and the patients of the study group were categorized as MO or IM based on the sequence variations. Univariate and multivariate analyses were used to determine the important clinicopathologic characteristics in the two groups. Results: In the study group, 20 cases were categorized as MO, and 22 as IM, whereas all 20 cases in the control group were characterized as IM. Several factors significantly differed between the IM and MO patients, including hepatitis B e antigen (HBeAg), cumulative tumor size, tumor nodule location, cirrhosis, portal vein and/or microvascular tumor embolus and the histological grade of the primary nodule. Multivariate analysis further demonstrated that cirrhosis and portal vein and/or microvascular tumor thrombus were independent factors differentiating between IM and MO patients. The tumor-free survival time of the MO subjects was significantly longer than that of the IM subjects ($25.7{\pm}4.8$ months vs. $8.9{\pm}3.1$ months, p=0.017). Similarly, the overall survival time of the MO subjects was longer ($31.6{\pm}5.3$ months vs. $15.4{\pm}3.4$ months, p=0.024). The multivariate analysis further demonstrated that the original type (p=0.035) and Child-Pugh grade (p<0.001) were independent predictors of tumor-free survival time. Cirrhosis (p=0.011), original type (p=0.034) and Child-Pugh grade (p<0.001) were independent predictors of overall survival time. Conclusions: HBeAg, cumulative tumor size, tumor nodule location, cirrhosis, portal vein and/or microvascular tumor embolus and histological grade of the primary nodule are important factors for differentiating IM and MO. MO HCC patients might have a favorable outcome compared with IM patients.

Knockdown of GCF2/LRRFIP1 by RNAi Causes Cell Growth Inhibition and Increased Apoptosis in Human Hepatoma HepG2 Cells

Li, Jing-Ping,Cao, Nai-Xia,Jiang, Ri-Ting,He, Shao-Jian,Huang, Tian-Ming,Wu, Bo,Chen, De-Feng,Ma, Ping,Chen, Li,Zhou, Su-Fang,Xie, Xiao-Xun,Luo, Guo-Rong Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Background: GC-binding factor 2 (GCF2) is a transcriptional regulator that represses transcriptional activity of the epidermal growth factor receptor (EGFR) by binding to a specific GC-rich sequence in the EGFR gene promoter. In addition to this function, GCF2 has also been identified as a tumor-associated antigen and regarded as a potentially valuable serum biomarker for early human hepatocellular carcinoma (HCC) diagnosis. GCF2 is high expressed in most HCC tissues and cell lines including HepG2. This study focused on the influence of GCF2 on cell proliferation and apoptosis in HepG2 cells. Materials and Methods: GCF2 expression at both mRNA and protein levels in HepG2 cells was detected with reverse transcription (RT) PCR and Western blotting, respectively. RNA interference (RNAi) technology was used to knock down GCF2 mRNA and protein expression. Afterwards, cell viability was analyzed with a Cell Counting Kit-8 (CCK-8), and cell apoptosis and caspase 3 activity by flow cytometry and with a Caspase 3 Activity Kit, respectively. Results: Specific down-regulation of GCF2 expression caused cell growth inhibition, and increased apoptosis and caspase 3 activity in HepG2 cells. Conclusions: These primary results suggest that GCF2 may influence cell proliferation and apoptosis in HepG2 cells, and also provides a molecular basis for further investigation into the possible mechanism at proliferation and apoptosis in HCC.

SERS study of surface plasmon resonance induced carrier movement in Au@Cu₂O core-shell nanoparticles

Chen, Lei,Zhang, Fan,Deng, Xin-Yu,Xue, Xiangxin,Wang, Li,Sun, Yantao,Feng, Jing-Dong,Zhang, Yongjun,Wang, Yaxin,Jung, Young Mee Elsevier 2018 Spectrochimica acta. Part A, Molecular and biomole Vol.189 No.-

<P><B>Abstract</B></P> <P>A plasmon induced carrier movement enhanced mechanism of surface-enhanced Raman scattering (SERS) was investigated using a charge-transfer (CT) enhancement mechanism. Here, we designed a strategy to study SERS in Au@Cu<SUB>2</SUB>O nanoshell nanoparticles with different shell thicknesses. Among the plasmonically coupled nanostructures, Au spheres with Cu<SUB>2</SUB>O shells have been of special interest due to their ultrastrong electromagnetic fields and controllable carrier transfer properties, which are useful for SERS. Au@Cu<SUB>2</SUB>O nanoshell nanoparticles (NPs) with shell thicknesses of 48–56nm are synthesized that exhibit high SERS activity. This high activity originates from plasmonic-induced carrier transfer from Au@Cu<SUB>2</SUB>O to 4-mercaptobenzoic acid (MBA). The CT transition from the valence band (VB) of Cu<SUB>2</SUB>O to the second excited π-π* transition of MBA, and is of b<SUB>2</SUB> electronic symmetry, which was enhanced significantly. The Herzberg-Teller selection rules were employed to predict the observed enhanced b<SUB>2</SUB> symmetry modes. The system constructed in this study combines the long-range electromagnetic effect of Au NPs, localized surface plasmon resonance (LSPR) of the Au@Cu<SUB>2</SUB>O nanoshell, and the CT contribution to assist in understanding the SERS mechanism based on LSPR-induced carrier movement in metal/semiconductor nanocomposites.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We designed a shell-dependent Au@Cu<SUB>2</SUB>O nanoshell for SERS study. </LI> <LI> SERS contribution enables us to understand the possible enhancement of hybrid nanostructures. </LI> <LI> LSPR-induced carrier movement in Au@Cu<SUB>2</SUB>O nanocomposites. </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>We designed the shell-dependent Au@Cu<SUB>2</SUB>O core-shell nanoparticles (NPs) for SERS study. For the electron-hole pairs in the Cu<SUB>2</SUB>O, the plasmon induced resonant energy transfer from Au to the Cu<SUB>2</SUB>O and the direct electron transfer simultaneously which can be observed from the SERS intensity.</P> <P>[DISPLAY OMISSION]</P>