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>

The preparation, performance and lithiation mechanism of cobalt-doped zinc oxide as a high performance anode material for LIB

Yue Li,WanWan Li,Minhua Fang,XiaoLin Yao,Chao Chen,Miao Shui,Jie Shu,Yuanlong Ren 한국물리학회 2017 Current Applied Physics Vol.17 No.8

Zn1-xCoxO (0 x 0.15) anode material was prepared by an easy polyacrylamide assisted sol-gel route. The successful replacement of Zinc by Cobalt within Cobalt content x 0.09 was confirmed by structural characterization. The introduction of Cobalt element greatly improved the electro-chemical performances of the matrix Zinc oxide. Without carbon coating, at the 20th cycle, Zn0.91Co0.09O anode still preserved a capacity a little bit more than 1000 mA h g1 and a capacity more than 600 mA h g1 was retained at the end of the 50th cycle. Better rate capability was also witnessed. The SEM, EIS at OCV, CV and in situ XRD were further carried out to elucidate the lithiation mechanism. The role Cobalt doping played can be summarized as follows: the stabilization of the Li2Zn phase, the minimization of charge transfer resistance and the enhanced reversibility of the reduction from metal oxide to metal.

Towards Attacks and Defenses of Anonymous Communication Systems

Tianbo Lu,Puxin Yao1,Lingling Zhao,Yang Li,Feng Xie,Yamei Xia 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.1

Anonymous communication system has been hot topic in the field of information security, and attack techniques against anonymous systems are endless. This paper first classifies and summarizes the study of attacks against anonymous communication system in recent years, then analyzes the trend of the research on different attack technologies; secondly, it provides a comparative analysis of defense capability the mainstream anonymous communication system to the various attacks; Finally, combining the advantages and disadvantages of different systems, the authors propose an improved node selection and router forwarding algorithms for anonymous communication systems, and design an architecture of anonymous communications software based on the algorithm.

Effect of aberrantly methylated androgen receptor target gene PCDH7 on the development of androgen-independent prostate cancer cells

Siqi Xu,Xiaoyan Wu,Zhihua Tao,Hongsheng Li1,Chenliang Fan,Songjin Chen,Jianwei Guo,Yao Ning,Xuqi Hu 한국유전학회 2020 Genes & Genomics Vol.42 No.3

Background Androgen-independent prostate cancer (AIPC) is an extremely malignant tumor developed from the androgen dependent (ADPC). However, the mechanism of transition process from ADPC to AIPC remains unknown. Objective Here we aimed to identify the androgen receptor (AR) target gene and its roles in AIPC. Methods Target genes of AR were identified by ChIP-seq in AIPC cells. AR target gene PCDH7 was detected by real time PCR and western blot. Methylation of PCDH7 was measured by bisulfite sequencing and bisulfite amplicon sequencing. Cell growth, invasion and apoptosis were measured by CCK-8, transwell and flow cytometry, respectively. Results AR was significantly enriched in the upstream of PCDH7 gene. The expression of PCDH7 was significantly decreased, while the methylation of PCDH7 was increased in the AIPC cells compared to the ADPC cells. DNA methyltransferase inhibitor significantly suppressed the methylation and increased the mRNA and protein level of PCDH7. Moreover, overexpression of DNMT1 remarkably reduced the mRNA and protein level of PCDH7. DNA methyltransferase inhibitor decreased the cell growth and invasion while promote the cell apoptosis in the AIPC cells. AR significantly target PCDH7, whose hypermethylation may repress cell growth and invasion, and promote apoptosis in AIPC. Conclusions This study might provide a novel potential target for the treatment of AIPC.

Robust, self-cleaning, amphiphobic coating with flower-like nanostructure on micro-patterned polymer substrate

Yao, Wenhui,Li, Lei,Li, Oi Lun,Cho, Young-Wook,Jeong, Myung-Yung,Cho, Young-Rae Elsevier 2018 Chemical Engineering Journal Vol.352 No.-

<P><B>Abstract</B></P> <P>Many superhydrophobic surfaces lose their repellency to water owing to the contamination of organic liquids or mechanical damage. Though amphiphobic coatings can repel both water and organic liquids, the poor mechanical and chemical stabilities significantly restrict their practical applications. Herein, we demonstrated a hydrothermal method to synthesize micro-patterned substrates bearing NiAl layered double hydroxide with flower-like nanostructures, which resemble the surface morphology of a lotus leaf. The surface was further modified by a low-surface-energy material of perfluorooctanoic acid through a solution immersion method. The binder-free coating formed in-situ on the substrate showed a good adhesion quality of 5B (ASTM D-3359). The coating possessed high repellency to different liquid droplets, including water, diiodomethane, ethylene glycol, soybean oil, etc., with surface tensions ranging from 72.7 to 22.4 mN m<SUP>−1</SUP>. Due to the excellent self-cleaning property, the contaminant on the surface was easily cleaned as the water droplet rolled off. Moreover, the coating exhibited good mechanical and chemical robustness in some extreme conditions, such as gas blowing, sea sand abrasion, and chemical immersion tests. These good performances made the coating possible to be applied widely in various practical applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Flower-like nanostructure of NiAl-LDH was synthesized on micro-patterned polymer. </LI> <LI> The hierarchical structure showed good amphiphobicity after fluorination. </LI> <LI> The amphiphobic surface possessed excellent self-cleaning performance. </LI> <LI> The amphiphobic surface exhibited good mechanical and chemical robustness. </LI> <LI> The coating can be used in anti-contaminant, self-cleaning, and biomedical device. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Visible light assisted NO₂ sensing at room temperature by CdS nanoflake array

Li, Hua-Yao,Yoon, Ji-Won,Lee, Chul-Soon,Lim, Kyeorei,Yoon, Ji-Wook,Lee, Jong-Heun Elsevier 2018 Sensors and actuators. B, Chemical Vol.255 No.3

<P><B>Abstract</B></P> <P>A Highly ordered CdS nanoflake array was fabricated by CVD, and its gas sensing characteristics were investigated. The sensor exhibited high response (resistance ratio) of 89% to 5 part per million (ppm) nitrogen dioxide (NO<SUB>2</SUB>) under green LED illumination (wavelength 500–540nm, irradiance 21W/m<SUP>2</SUP>) with excellent selectivity and little interference by humidity. Moreover, the sensor showed promising potential for operating under fluorescent lamp and natural solar light, which can be used for medical diagnosis and indoor/outdoor environment monitoring. This performance is attributed to the low band gap energy (2.4eV) of CdS and the unique morphology of nanoflake array which can enhance both the light absorption and conductivity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CdS NO<SUB>2</SUB> gas sensor operated under both fluorescent lamp and natural solar light. </LI> <LI> 2D nanoflake array CdS films for enhanced light absorption and charge transport. </LI> <LI> CdS gas sensor with high response to NO<SUB>2</SUB>, little influence by humidity. </LI> <LI> Elucidation of visible-light-enhanced NO<SUB>2</SUB> sensing mechanism. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Impact of pillar configuration on the amphiphobicity of micro-patterned polymer surface

Yao, Wenhui,Li, Oi Lun,Kang, Young-Joon,Jeong, Myung-Yung,Cho, Young-Rae Elsevier 2018 Vacuum Vol.156 No.-

<P><B>Abstract</B></P> <P>Hydrophobic surfaces are easily contaminated by oil owing to its lower surface tension, which significantly limits their potential applications. In this study, micro-patterned surfaces with cylindrical or square pillar arrays were fabricated on a polycarbonate substrate by the thermal imprinting process. The geometry and size of the pillars were varied to obtain different samples, whereas the height of the pillars was kept constant. The surface of each micro-patterned sample was fluorinated with perfluorooctanoic acid. With the aim of characterizing the wetting behavior of the samples, droplets of water and oily liquids with different surface tensions were employed to measure the contact angles. In addition, the applicability of the Wenzel and Cassie equations for explaining the wetting mechanisms of droplets on the surfaces of the micro-patterned samples was systematically investigated. The prediction obtained using the Wenzel equation was found to differ considerably from the experimental results, whereas the Cassie equation was found to be acceptable for satisfactorily explaining the wetting behaviors of liquids on the micro-patterned samples. The main factor influencing the surface wettability of the micro-patterned sample was not the pillar geometry, but rather the pillar configuration, e.g., the solid area fraction, groove fraction, and spacing between pillars.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Micro-patterned surface with pillar array is formed by a thermal imprinting method. </LI> <LI> The micro-patterned surface is repellent to both water and oily liquids. </LI> <LI> Effect of pillar configuration on the amphiphobicity is studied. </LI> <LI> Wetting mechanism of liquid droplet on the micro-patterned surface is proposed. </LI> </UL> </P>

Discriminative detection of indoor volatile organic compounds using a sensor array based on pure and Fe-doped In₂O₃ nanofibers

Lee, Chul-Soon,Li, Hua-Yao,Kim, Bo-Young,Jo, Young-Moo,Byun, Hyung-Gi,Hwang, In-Sung,Abdel-Hady, Faissal,Wazzan, Abdulaziz A.,Lee, Jong-Heun Elsevier 2019 Sensors and actuators. B Chemical Vol.285 No.-

<P><B>Abstract</B></P> <P>Representative indoor volatile organic compounds (VOCs) such as benzene, xylene, toluene, formaldehyde, and ethanol need to be detected in a highly sensitive and discriminative manner because of their different impact on human health. In this study, pure and 0.05, 0.1, 0.3, and 0.5 at% Fe-doped In<SUB>2</SUB>O<SUB>3</SUB> nanofibers were prepared by electrospinning and their gas sensing characteristics toward the aforementioned VOCs were investigated. The doping of In<SUB>2</SUB>O<SUB>3</SUB> nanofiber sensor with 0.05 and 0.1 at% Fe shifted the temperature to show the maximum responses to benzene, xylene, and toluene, and reduced responses to ethanol and formaldehyde, thus demonstrating changed gas selectivity. The gas sensing characteristics of 0.5 at% Fe-doped In<SUB>2</SUB>O<SUB>3</SUB> nanofiber sensor were substantially different from those of the other sensors. Significantly different gas sensing patterns of pure and Fe-doped In<SUB>2</SUB>O<SUB>3</SUB> sensors could be used to discriminate between the five different VOCs at 375 °C and to distinguish between the aromatic and non-aromatic gases at all sensing temperatures. The mechanism underlying the Fe-induced change in gas sensing characteristics has been discussed in relation to the variation of catalytic activity, morphology, oxygen adsorption, and charge carrier concentration.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Fabrication of a sensor array using pure and Fe-doped In<SUB>2</SUB>O<SUB>3</SUB> nanofibers. </LI> <LI> Discriminative detection of benzene, xylene, toluene, ethanol, and formaldehyde. </LI> <LI> Distinction between aromatic and non-aromatic indoor pollutants using sensor array. </LI> <LI> Gas sensing mechanism underlying Fe-induced change in response and selectivity. </LI> </UL> </P>

Highly discriminative and sensitive detection of volatile organic compounds for monitoring indoor air quality using pure and Au-loaded 2D In₂O₃ inverse opal thin films

Lee, Chul-Soon,Dai, Zhengfei,Kim, Do Hong,Li, Hua-Yao,Jo, Young-Moo,Kim, Bo-Young,Byun, Hyung-Gi,Hwang, Insung,Lee, Jong-Heun Elsevier 2018 Sensors and actuators. B Chemical Vol.273 No.-

<P><B>Abstract</B></P> <P>The lack of gas selectivity in oxide semiconductor chemiresistors has long been an obstacle to realizing discriminative detection of indoor volatile organic compounds (VOCs) with different health impacts. A simple and reliable algorithm to discriminate between critically harmful aromatic VOCs (benzene, xylene, and toluene) and less harmful ethanol is suggested by the simple combination of sensor signals from pure In<SUB>2</SUB>O<SUB>3</SUB> and Au-loaded In<SUB>2</SUB>O<SUB>3</SUB> 2D inverse opal (IO) thin films prepared by heat-treating the precursor-dipped self-assembled polystyrene templates and Au deposition. The Au-loaded In<SUB>2</SUB>O<SUB>3</SUB> IO sensor showed unprecedentedly high responses to 5 ppm ethanol (resistance ratio = 1640.2) and comparably high responses to 5 ppm benzene, <I>p-</I>xylene, and toluene (resistance ratio range of 674.5–1012.9). Such high gas responses were attributed to the periodically porous and thus highly gas-accessible structures, while the clear discrimination between aromatic VOCs and ethanol was achieved by tuning gas selectivity through systematic control of the size, morphology, and loading concentration of Au nano-catalysts. The results of this study can be used for reliable and precise monitoring of indoor air pollutants.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Discriminative detection of indoor pollutant gases using Au-In<SUB>2</SUB>O<SUB>3</SUB> 2D Inverse Opals. </LI> <LI> Selective and sensitive detection of ethanol using In<SUB>2</SUB>O<SUB>3</SUB> 2D Inverse Opals. </LI> <LI> Ultrahigh response (resistance ratio = ∼1000) of Au-In<SUB>2</SUB>O<SUB>3</SUB> sensor to 5 ppm <I>p</I>-xylene. </LI> <LI> A simple and reliable algorithm for gas selectivity using two-sensor array. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

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.