High-Density Periodically Ordered Magnetic Cobalt Ferrite Nanodot Arrays by Template-Assisted Pulsed Laser Deposition

Gao, Xingsen,Liu, Lifeng,Birajdar, Balaji,Ziese, Michael,Lee, Woo,Alexe, Marin,Hesse, Dietrich WILEY-VCH Verlag 2009 Advanced Functional Materials Vol.19 No.21

<P>A novel nanopatterning method using pulsed laser deposition through an ultrathin anodic aluminium oxide (AAO) membrane mask is proposed to synthesize well-ordered nanodot arrays of magnetic CoFe<SUB>2</SUB>O<SUB>4</SUB> that feature a wide range of applications like sensors, drug delivery, and data storage. This technique allows the adjustment of the array dimension from ∼35 to ∼300 nm in diameter and ∼65 to ∼500 nm in inter-dot distance. The dot density can be as high as 0.21 Terabit in.<SUP>−2</SUP>. The microstructure of the nanodots is characterized by SEM, TEM, and XRD and their magnetic properties are confirmed by well-defined magnetic force microscopy contrasts and by hysteresis loops recorded by a superconducting quantum interference device. Moreover, the high stability of the AAO mask enables the epitaxial growth of nanodots at a temperature as high as 550 °C. The epitaxial dots demonstrate unique complex magnetic domains such as bubble and stripe domains, which are switchable by external magnetic fields. This patterning method creates opportunities for studying novel physics in oxide nanomagnets and may find applications in spintronic devices.</P> <B>Graphic Abstract</B> <P>Well-ordered arrays of magnetic CoFe<SUB>2</SUB>O<SUB>4</SUB> nanodots are synthesized by a nanopatterning method using pulsed laser deposition through an ultrathin anodic aluminium oxide membrane. This technique allows a wide-range adjustment of array periodicity and dot dimension, as well as epitaxial growth of the nanodots. The epitaxial dots demonstrate complex magnetic domains such as bubble and stripe domains. <img src='wiley_img/1616301X-2009-19-21-ADFM200900422-content.gif' alt='wiley_img/1616301X-2009-19-21-ADFM200900422-content'> </P>

Pretreatments of Broussonetia papyrifera: in vitro assessment on gas and methane production, fermentation characteristic, and methanogenic archaea profile

Dong Lifeng,Gao Yanhua,Jing Xuelan,Guo Huiping,Zhang Hongsen,Lai Qi,Diao Qiyu 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.9

Objective: The present study was conducted to examine the gas production, fermentation characteristics, nutrient degradation, and methanogenic community composition of a rumen fluid culture with Broussonetia papyrifera (B. papyrifera) subjected to ensiling or steam explosion (SE) pretreatment. Methods: Fresh B. papyrifera was collected and pretreated by ensiling or SE, which was then fermented with ruminal fluids as ensiled B. papyrifera group, steam-exploded B. papyrifera group, and untreated B. papyrifera group. The gas and methane production, fermentation characteristics, nutrient degradation, and methanogenic community were determined during the fermentation. Results: Cumulative methane production was significantly improved with SE pretreatment compared with ensiled or untreated biomass accompanied with more volatile fatty acids production. After 72 h incubation, SE and ensiling pretreatments decreased the acid detergent fiber contents by 39.4% and 22.9%, and neutral detergent fiber contents by 10.6% and 47.2%, respectively. Changes of methanogenic diversity and abundance of methanogenic archaea corresponded to the variations in fermentation pattern and methane production. Conclusion: Compared with ensiling pretreatment, SE can be a promising technique for the efficient utilization of B. papyrifera, which would contribute to sustainable livestock production systems. Objective: The present study was conducted to examine the gas production, fermentation characteristics, nutrient degradation, and methanogenic community composition of a rumen fluid culture with Broussonetia papyrifera (B. papyrifera) subjected to ensiling or steam explosion (SE) pretreatment.Methods: Fresh B. papyrifera was collected and pretreated by ensiling or SE, which was then fermented with ruminal fluids as ensiled B. papyrifera group, steam-exploded B. papyrifera group, and untreated B. papyrifera group. The gas and methane production, fermentation characteristics, nutrient degradation, and methanogenic community were determined during the fermentation.Results: Cumulative methane production was significantly improved with SE pretreatment compared with ensiled or untreated biomass accompanied with more volatile fatty acids production. After 72 h incubation, SE and ensiling pretreatments decreased the acid detergent fiber contents by 39.4% and 22.9%, and neutral detergent fiber contents by 10.6% and 47.2%, respectively. Changes of methanogenic diversity and abundance of methanogenic archaea corresponded to the variations in fermentation pattern and methane production.Conclusion: Compared with ensiling pretreatment, SE can be a promising technique for the efficient utilization of B. papyrifera, which would contribute to sustainable livestock production systems.

Eucommia ulmoides Bark Protects Against Renal Injury in Cadmium-Challenged Rats

Erwei Liu,Lifeng Han,Jialong Wang,Wei He,Haihua Shang,Xiumei Gao,Tao Wang 한국식품영양과학회 2012 Journal of medicinal food Vol.15 No.3

Eucommia ulmoides Oliver is a perennial woody plant distributed widely in China. To characterize some major compounds in E. ulmoides bark extract, six compounds were identified via high-performance liquid chromatography qualitative analysis. E. ulmoides bark extract protects against cadmium-induced oxidative damage in rat kidneys. Two compounds of E. ulmoides bark extract, geniposide and genipin, which were identified both in serum and in kidney tissue, showed inhibitory effects on nitric oxide production. This study provides biological evidence supporting the usefulness of E. ulmoides bark against cadmium-induced toxic oxidative stress in rat kidney tissue.

Oxygen vacancies assisted LaFeO3 derived from metal organic frameworks endows a practical HCHO sensor with excellent sensing characteristics

Lulu Guo,Shushu Zhao,Guimao Yang,Lifeng Gao,Yanhong Wu,Xuguang Zhang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.126 No.-

Perovskite oxide semiconductors have attracted tremendous interest in gas sensing due to their promisingproperties of tunable active sites, excellent catalytic ability and good structural stability. Nevertheless, the rapid synthesis of perovskite oxides and controlled regulation of their surface oxygenvacancies remains a great challenge. Herein, we report a novel metal–organic frameworks (MOFs) selftemplatestrategy for the rapid and large-scale preparation of LaFeO3 nanoparticles (MLaFeO3) withabundant oxygen vacancies. Benefit from the introduction of oxygen vacancies, the resultantMLaFeO3 gas sensor exhibit excellent formaldehyde (HCHO) sensing performance at a low operatingtemperature of 160 C, including high sensitivity (Rg/Ra = 8.9 @ 100 ppm), fast response/recovery rate(53 s/32 s), low detection limit (1 ppm) and excellent selectivity. Comprehensive density functional theory(DFT) calculation and spectral characterizations reveal that oxygen vacancies play a vital role in promotingthe adsorption and activation of O2 and HCHO molecules, and accelerate the chemical reaction onthe sensing materials surface. Most importantly, it proves the promising application of MLaFeO3 sensorin food safety assessment. This work not only provides a simple strategy for constructing oxygen vacanciesenriched LaFeO3, but also demonstrates the application potential of LaFeO3-based gas sensors in thefield of formaldehyde detection.

Maternal nutrition altered embryonic MYOD1, MYF5, and MYF6 gene expression in genetically fat and lean lines of chickens

Li Feng,Yang Chunxu,Xie Yingjie,Gao Xiang,Zhang Yuanyuan,Ning Hangyi,Liu Guangtao,Chen Zhihui,Shan Anshan 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.8

Objective: The objectives of this study were to evaluate the effects of daily feed intake during the laying period on embryonic myogenic differentiation 1 (MYOD1), myogenic factor 5 (MYF5), and myogenic factor 6 (MYF6) gene expression in genetically fat and lean lines of chickens. Methods: An experiment in a 2×2 factorial design was conducted with two dietary intake levels (100% and 75% of nutrition recommendation) and two broiler chicken lines (fat and lean). Two lines of hens (n = 384 for each line) at 23th week of age were randomly divided into 4 treatments with 12 replicates of 16 birds. The experiment started at 27th week of age (5% egg rate) and ended at 54th week of age. Hatched eggs from the medium laying period were collected. Real time polymerase chain reaction analysis was used to analyse the MYOD1, MYF5, and MYF6 mRNA levels of E7, E9, E11, E13, and E15 body tissues and E17, E19, and E21 chest and thigh muscle samples. Results: The results indicated that there were significant effects of line, dietary intake, and interactions between them on MYOD1, MYF5, and MYF6 gene mRNA expression levels in embryonic tissues. Low daily feed intake did not change the expression trend of MYOD1 mRNA in either line, but changed the peak values, especially in lean line. Low daily feed intake altered the trend in MYF5 mRNA expression level in both lines and apparently delayed its onset. There was no apparent effect of low daily feed intake on the trends of MYF6 mRNA expression levels in either line, but it significantly changed the values on many embryonic days. Conclusion: Maternal nutrient restriction affects myogenesis and is manifested in the expression of embryonic MYOD1, MYF5, and MYF6 genes. Long term selection for fat deposition in broiler chickens changes the pattern and intensity of myogenesis. Objective: The objectives of this study were to evaluate the effects of daily feed intake during the laying period on embryonic myogenic differentiation 1 (<i>MYOD1</i>), myogenic factor 5 (<i>MYF5</i>), and myogenic factor 6 (<i>MYF6</i>) gene expression in genetically fat and lean lines of chickens.Methods: An experiment in a 2×2 factorial design was conducted with two dietary intake levels (100% and 75% of nutrition recommendation) and two broiler chicken lines (fat and lean). Two lines of hens (n = 384 for each line) at 23th week of age were randomly divided into 4 treatments with 12 replicates of 16 birds. The experiment started at 27th week of age (5% egg rate) and ended at 54th week of age. Hatched eggs from the medium laying period were collected. Real time polymerase chain reaction analysis was used to analyse the <i>MYOD1</i>, <i>MYF5</i>, and <i>MYF6</i> mRNA levels of E7, E9, E11, E13, and E15 body tissues and E17, E19, and E21 chest and thigh muscle samples.Results: The results indicated that there were significant effects of line, dietary intake, and interactions between them on <i>MYOD1</i>, <i>MYF5</i>, and <i>MYF6</i> gene mRNA expression levels in embryonic tissues. Low daily feed intake did not change the expression trend of <i>MYOD1</i> mRNA in either line, but changed the peak values, especially in lean line. Low daily feed intake altered the trend in <i>MYF5</i> mRNA expression level in both lines and apparently delayed its onset. There was no apparent effect of low daily feed intake on the trends of <i>MYF6</i> mRNA expression levels in either line, but it significantly changed the values on many embryonic days.Conclusion: Maternal nutrient restriction affects myogenesis and is manifested in the expression of embryonic <i>MYOD1</i>, <i>MYF5</i>, and <i>MYF6</i> genes. Long term selection for fat deposition in broiler chickens changes the pattern and intensity of myogenesis.

Boosting oxygen reduction catalysis with abundant copper single atom active sites

Li, Feng,Han, Gao-Feng,Noh, Hyuk-Jun,Kim, Seok-Jin,Lu, Yalin,Jeong, Hu Young,Fu, Zhengping,Baek, Jong-Beom The Royal Society of Chemistry 2018 Energy & environmental science Vol.11 No.8

<P>With their high catalytic activity, stability, selectivity, and 100% atom utilization, single atomic non-noble metal based materials are valuable alternatives to efficient but expensive Pt based catalysts. For efficient catalysis, single-atom catalysts must expose abundant single atomic metal active centers. Here, we report the rational design and synthesis of a Cu single-atom catalyst with high Cu content of over 20.9 wt%, made of single atomic Cu anchored into an ultrathin nitrogenated two-dimensional carbon matrix (Cu-N-C). The high Cu content was achieved by the introduction of additional N species, which can securely trap and protect the Cu atoms. During oxygen reduction, the single atomic Cu exhibited over 54 times higher mass activity than metallic Cu nanoparticles at a potential of 0.85 V <I>versus</I> a reversible hydrogen electrode (RHE). Furthermore, the Cu-N-C exhibited 3.2 times higher kinetic current at 0.85 V (<I>vs.</I> RHE), and a much lower Tafel slope (37 mV dec<SUP>−1</SUP>), as well as better methanol/carbon monoxide tolerance and long-term stability than commercial Pt/C. Density functional theory (DFT) calculations reveal that the Cu active sites exhibit improved O-O bond stretching and favorable adsorption energies of O2 and OOH for four-electron oxygen reduction.</P>

Macroporous Inverse Opal-like Mo_<i>x</i>C with Incorporated Mo Vacancies for Significantly Enhanced Hydrogen Evolution

Li, Feng,Zhao, Xianglong,Mahmood, Javeed,Okyay, Mahmut Sait,Jung, Sun-Min,Ahmad, Ishfaq,Kim, Seok-Jin,Han, Gao-Feng,Park, Noejung,Baek, Jong-Beom American Chemical Society 2017 ACS NANO Vol.11 No.7

<P>The hydrogen evolution reaction (HER) is one of the most important pathways for producing pure and clean hydrogen. Although platinum (Pt) is the most efficient HER electrocatalyst, its practical application is significantly hindered by high cost and scarcity. In this work, an MoxS with incorporated Mo vacancies and macroporous inverse opal-like (IOL) structure (MoxC-IOL) was synthesized and studied as a low-cost efficient HER electrocatalyst. The macroporous IOL structure was controllably fabricated using a facile-hard template strategy. As a result of the combined benefits of the Mo vacancies and structural advantages, including appropriate hydrogen binding energy, large exposed surface, robust IOL structure and fast mass/charge transport, the synthesized MoxC-IOL exhibited significantly enhanced HER electrocatalytic performance with good stability, with performance comparable or superior to Pt wire in both acidic and alkaline solutions.</P>