Catalytic synthesis and enhanced Curie temperature of ε-Fe₃N@C nanostructure synthesized in a tetraethylenepentamine solution

Li, Yong,Pan, Desheng,Li, Da,Feng, Yang,Choi, C.J.,Liu, Wei,Zhang, Zhidong Elsevier 2018 Journal of magnetism and magnetic materials Vol.465 No.-

<P><B>Abstract</B></P> <P>ε-Fe<SUB>3</SUB>N@C nanocrystals without oxidation are one-pot synthesized by using the iron(II) acetylacetonate and tetraethylenepentamine (TEPA) as Fe and N precursors under a low temperature (533 K) in the presence of a small quantity of Pt atoms as the co-catalyst. The ε-Fe<SUB>3</SUB>N@C nanoparticles with a core-shell structure are nearly spherical and have a wide particle size distribution of 100–500 nm in diameter. Fe nanoparticles obtained by reduction of Fe<SUP>2+</SUP> with TEPA are an effective catalyzer for decomposing TEPA to produce N and C atoms at a temperature much lower than the boiling point of TEPA. The diffusion of N atoms into Fe nanoparticles for the formation of ε-Fe<SUB>3</SUB>N@C is proposed, based on the results obtained by kinetically controlling the synthetic temperature and surfactants. The ε-Fe<SUB>3</SUB>N@C nanoparticles have an excellent saturation magnetization of 135.5 emu/g at room temperature. A significantly enhanced Curie temperature (T<SUB>C</SUB>) of 614 K is reached in the present ε-Fe<SUB>3</SUB>N@C nanoparticles, which is much higher than the T<SUB>C</SUB> values in the previously reported ε-Fe<SUB>3</SUB>N<SUB>x</SUB>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Tetraethylenepentamine is proposed as a new N source to synthesize Fe nitride. </LI> <LI> Core-shelled ε-Fe<SUB>3</SUB>N@C nanoparticles are one-pot synthesized at 260 °C. </LI> <LI> Curie temperature of ε-Fe<SUB>3</SUB>N is significantly enhanced to 614 K. </LI> <LI> ε-Fe<SUB>3</SUB>N@C shows a high saturation magnetization of 135.5 emu/g at 300 K. </LI> </UL> </P>

Biochar-supported nZVI (nZVI/BC) for contaminant removal from soil and water: A critical review

Wang, Shengsen,Zhao, Mingyue,Zhou, Min,Li, Yuncong C.,Wang, Jun,Gao, Bin,Sato, Shinjiro,Feng, Ke,Yin, Weiqin,Igalavithana, Avanthi Deshani,Oleszczuk, Patryk,Wang, Xiaozhi,Ok, Yong Sik Elsevier 2019 Journal of hazardous materials Vol.373 No.-

<P><B>Abstract</B></P> <P>The promising characteristics of nanoscale zero-valent iron (nZVI) have not been fully exploited owing to intrinsic limitations. Carbon-enriched biochar (BC) has been widely used to overcome the limitations of nZVI and improve its reaction with environmental pollutants. This work reviews the preparation of nZVI/BC nanocomposites; the effects of BC as a supporting matrix on the nZVI crystallite size, dispersion, and oxidation and electron transfer capacity; and its interaction mechanisms with contaminants. The literature review suggests that the properties and preparation conditions of BC (e.g., pore structure, functional groups, feedstock composition, and pyrogenic temperature) play important roles in the manipulation of nZVI properties. This review discusses the interactions of nZVI/BC composites with heavy metals, nitrates, and organic compounds in soil and water. Overall, BC contributes to the removal of contaminants because it can attenuate contaminants on the surface of nZVI/BC; it also enhances electron transfer from nZVI to target contaminants owing to its good electrical conductivity and improves the crystallite size and dispersion of nZVI. This review is intended to provide insights into methods of optimizing nZVI/BC synthesis and maximizing the efficiency of nZVI in environmental cleanup.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Aggregation and passivation of nZVI can be alleviated by surfactants and doping methods. </LI> <LI> BC hinders corrosion and improves the dispersion and electron transfer of nZVI. </LI> <LI> Properties of nZVI depend on those of the BC, feedstock and pyrogenic temperature. </LI> <LI> BC enhances electron transfer from nZVI to the contaminants due to the presence of quinone and graphene moieties. </LI> <LI> nZVI/BC shows strong ability to remove HMs, nitrates, and organic contaminants in soil and water. </LI> </UL> </P>

Sources, distribution, bioavailability, toxicity, and risk assessment of heavy metal(loid)s in complementary medicines

Bolan, Shiv,Kunhikrishnan, Anitha,Seshadri, Balaji,Choppala, Girish,Naidu, Ravi,Bolan, Nanthi S.,Ok, Yong Sik,Zhang, Ming,Li, Chun-Guang,Li, Feng,Noller, Barry,Kirkham, Mary Beth Elsevier 2017 Environment international Vol.108 No.-

<P><B>Abstract</B></P> <P>The last few decades have seen the rise of alternative medical approaches including the use of herbal supplements, natural products, and traditional medicines, which are collectively known as ‘Complementary medicines’. However, there are increasing concerns on the safety and health benefits of these medicines. One of the main hazards with the use of complementary medicines is the presence of heavy metal(loid)s such as arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg). This review deals with the characteristics of complementary medicines in terms of heavy metal(loid)s sources, distribution, bioavailability, toxicity, and human risk assessment. The heavy metal(loid)s in these medicines are derived from uptake by medicinal plants, cross-contamination during processing, and therapeutic input of metal(loid)s. This paper discusses the distribution of heavy metal(loid)s in these medicines, in terms of their nature, concentration, and speciation. The importance of determining bioavailability towards human health risk assessment was emphasized by the need to estimate daily intake of heavy metal(loid)s in complementary medicines. The review ends with selected case studies of heavy metal(loid) toxicity from complementary medicines with specific reference to As, Cd, Pb, and Hg. The future research opportunities mentioned in the conclusion of review will help researchers to explore new avenues, methodologies, and approaches to the issue of heavy metal(loid)s in complementary medicines, thereby generating new regulations and proposing fresh approach towards safe use of these medicines.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A first-time comprehensive overview on the health risk assessment of heavy metal(loid)s in complementary medicines </LI> <LI> Ayurvedic medicines contain toxic levels of heavy metal(loid)s including As, Cd, Hg and Pb </LI> <LI> The bioavailability of metal(loid)s in complementary medicines depends on speciation of these metals </LI> <LI> Regular intake of some complementary medicines has caused metal(loid) toxicity in humans </LI> <LI> Health risk assessment can be achieved based on the daily intake of complementary medicines and total metal(loid) content </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Interactions between heavy metal(loid)s and complementary medicines.</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>

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>

Blast diseases influenced on agronomic and eating quality traits of rice in Korea

Feng-peng Li,Won-Hee Ra,Yong-Jin Park,Il-Pyung Ahn 한국육종학회 2014 한국육종학회 심포지엄 Vol.2014 No.07

Rice (Oryza sativa L.) is one of the most important staple foods that feed more than 50% of the world’s population. With the improving of people’s living standard, eating quality of rice become the most important aims in current breeding programs. Amylose content (AC) and gelatinization temperature (GT) are the two main measures to estimate the rice grain quality. In rice, a total of 27 genes directly involved the rice starch biosynthesis effecting on the rice eating quality. It clearly identified chromosome 6 to be rich in the genes related to AC and GT properties (GBSS I, SSIIa and SBE I) along with other genomic regions scattered in rice genome. Rice blast, caused by the fungal pathogen M. oryzae, is the most devastating disease of rice and severely affects crop stability and sustainability worldwide. Many fungal genes involved in pathogenicity and rice genes involved in effector recognition and defense responses have been identified over the past decade. A total of 99 and 22 blast resistance genes have been identified and cloned; in which 45% were found in japonica cultivars, 51% in indica cultivars, and the rest 4% in wild rice species. Among them, three major resistance gene clusters have been characeterized: the Pik locus on Chromosome 11, and the Pita locus on Chromosome 12, the Piz locus on Chromosome 6 closely to the starch synthesis-related genes. These results could be important clues for studying the relationship between resistance / susceptible materials and eating quality.

Transcriptome profiling of Shindongjin and Sugary mutant at grain-filling stages using RNA-Seq

Feng-Peng Li,Min-Young Yoon,Gang Li,Yong-Jin Park 한국육종학회 2013 한국육종학회 심포지엄 Vol.2013 No.07

Rice (Oryza sativa) is an excellent model monocot with a known genome sequence for studying developmental seeds. In the study, the seeds of 10th day after flowering (DAF) were conducted RNA-Seq of the variety Shindongjin and Sugary mutant using RNA-seq technique. Approximately 202 and 214 million high-quality paired-end reads (101-bp in size) were generated in Shindongjin and Sugary mutant, respectively. Comprehensive analysis on the transcript levels of genes which encode starch-synthesis enzymes is fundamental for the assessment of the function of each enzyme and the regulatory mechanism of starch biosynthesis in seeds. Quantitative real-time PCR was also used to validate the expression profiles of 28 rice genes encoding six classes of enzymes, viz., ADPglucose pyrophosphorylase (AGPase), starch synthase, starch branching enzyme, starch debranching enzyme, starch phosphorylase, and disproportionating enzyme at different developmental grain- filling stages (DAF 1-14) between Shindongjin and Sugary mutant. The results showed that the expression of most of starch synthesis genes were up-regulated except the cytosolic AGPase small subunit2b (AGPS2b), which sharply decreased at grain-filling stages in Sugary mutant. These results will expand our understanding of the complex molecular and cellular events in rice grain-filling stages and provide a fundamental understanding of future studies on developmental endosperm in rice and other cereal crops.

Research on the motion characteristics of a trans-media vehicle when entering water obliquely at low speed

Li, Yong-li,Feng, Jin-fu,Hu, Jun-hua,Yang, Jian The Society of Naval Architects of Korea 2018 International Journal of Naval Architecture and Oc Vol.10 No.2

This paper proposes a single control strategy to solve the problem of trans-media vehicle difficult control. The proposed control strategy is just to control the vehicle's air navigation, but not to control the underwater navigation. The hydrodynamic model of a vehicle when entering water obliquely at low speed has been founded to analyze the motion characteristics. Two methods have been used to simulate the vehicle entering water in the same condition: numerical simulation method and theoretical model solving method. And the results of the two methods can validate the hydrodynamic model founded in this paper. The entering water motion in the conditions of different velocity, different angle, and different attack angle has been simulated by this hydrodynamic model and the simulation has been analyzed. And the change rule of the vehicle's gestures and position when entering water has been obtained by analysis. This entering water rule will guide the follow-up of a series of research, such as the underwater navigation, the exiting water process and so on.

Cloning and Sequence Analysis of Glyceraldehyde-3-Phosphate Dehydrogenase Gene in Yak

Li, Sheng-Wei,Jiang, Ming-Feng,Liu, Yong-Tao,Yang, Tu-Feng,Wang, Yong,Zhong, Jin-Cheng Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.11

In order to study the biological function of gapdh gene in yak, and prove whether the gapdh gene was a useful intra-reference gene that can be given an important role in molecular biology research of yak, the cDNA sequence encoding glyceraldehyde-3-phosphate dehydrogenase from yak was cloned by the RT-PCR method using gene specific PCR primers. The sequence results indicated that the cloned cDNA fragment (1,008 bp) contained a 1,002 bp open reading frame, encoding 333 amino acids (AAs) with a molecular mass of 35.753 kDa. The deduced amino acids sequence showed a high level of sequence identity to Bos Taurus (99.70%), Xenopus laevis (94.29%), Homo sapiens (97.01%), Mus musculus (97.90%) and Sus scrofa (98.20%). The expression of yak's gapdh gene in heart, spleen, kidney and brain tissues was also detected; the results showed that the gapdh gene was expressed in all these tissues. Further analysis of yak GAPDH amino acid sequence implied that it contained a complete glyceraldehyde-3-phosphate dehydrogenase active site (ASCTTNCL) which ranged from 148 to 155 amino acid residues. It also contained two conserved domains, a NAD binding domain in its N-terminal and a complete catalytic domain of sugar transport in its C-terminal. The phylogenetic analysis showed that yak and Bos taurus were the closest species. The prediction of secondary structures indicated that GAPDH of yak had a similar secondary structure to other isolated GAPDH. The results of this study suggested that the gapdh gene of yak was similar to other species and could be used as the intra-reference to analyze the expression of other genes in yak.

Clinical Significance of Upregulation of mir-196a-5p in Gastric Cancer and Enriched KEGG Pathway Analysis of Target Genes

Li, Hai-Long,Xie, Shou-Pin,Yang, Ya-Li,Cheng, Ying-Xia,Zhang, Ying,Wang, Jing,Wang, Yong,Liu, Da-Long,Chen, Zhao-Feng,Zhou, Yong-Ning,Wu, Hong-Yan Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.5

Background: miRNAs are relatively recently discovered cancer biomarkers which have important implications for cancer early diagnosis, treatment and estimation of prognosis. Here we focussed on expression of mir-196a-5p in gastric cancer tissues and cell lines so as to analyse its significance for clinicopathologic characteristics and generate enriched KEGG pathways clustered by target genes for exploring its potential roles as a biomarker in gastric cancer. Materials and Methods: The expression of mir-196a-5p in poorly, moderate and well differentiated gastric cancer cell lines compared with GES-1 was detected by RT-qPCR, and the expression of mir-196a-5p in gastric cancer tissues comparing with adjacent non cancer tissues of 58 cases were also assessed by RT-qPCR. Subsequently, an analysis of clinical significance of mir-196a-5p in gastric cancer and enriched KEGG pathways was executed based on the miRWalk prediction database combined with bioinformatics tools DAVID 6.7 and Mirfocus 3.0. Results: RT-qPCR showed that mir-196a-5p was up-regulated in 6 poorly and moderate differentiated gastric cancer cell lines SGC-7901, MKN-45, MKN-28, MGC-803, BGC-823, HGC-27 compared with GES-1, but down-regulated in the highly differentiated gastric cancer cell line AGS. Clinical data indicated mir-196a-5p to beup-regulated in gastric cancer tissues (47/58). Overexpression of mir-196a-5p was associated with more extensive degree of lymph node metastasis and clinical stage (P < 0.05; x2 test). Enriched KEGG pathway analyses of predicted and validated targets in miRWalk combined with DAVID 6.7 and Mirfocus 3.0 showed that the targeted genes regulated by mir-196a-5p were involved in malignancy associated biology. Conclusions: Overexpression of mir-196a-5p is associated with lymph node metastasis and clinical stage, and enriched KEGG pathway analyses showed that targeted genes regulated by mir-196a-5p may contribute to tumorgenesis, suggesting roles as an oncogenic miRNA biomarker in gastric cancer.