Improved biological synthesis of gold nanoparticles using methanobactin

Jiaying Xin,Kai Lin,Yan Wang,Chungu Xia 한국응용생명화학회 2015 Applied Biological Chemistry (Appl Biol Chem) Vol.58 No.3

The present study reported a novel approach for the green synthesis of gold nanoparticles (AuNPs) by using methanobactin (Mb) from the spent medium of Methylosinus trichosporium 3011. This paper explored the synthesis of AuNPs under different Mb concentrations, temperatures, and reaction times. The biosynthesized AuNPs were characterized by using UV–Visible spectroscopy, fluorescence spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). Comparing with the previous research using hydroquinone as an extra electron donor to synthesis of AuNPs, this research was the first to show that rising temperature improved the formation rate of AuNPs in a higher concentration of Mb itself. The formation of AuNPs was confirmed by surface plasmon resonance using UV–Visible spectrophotometry. Fluorescence spectroscopy experiments revealed that Mb sample showed three prominent peaks. In addition, the fluorescence exhibited by Mb was rapidly quenched upon addition of HAuCl4. According to the image analysis performed on a TEM micrograph, the obtained AuNPs were predominantly spherical with an average size of 19.3 ± 5.5 nm. XPS analysis demonstrated that Mb molecules reduced Au(III) to Au(0). FTIR spectrum confirmed the involvement of biomass groups in capping and reduction of AuNPs, which increased the stability of the synthesized AuNPs.

A Land Imagined: Transsensorial States of Transmigration

Jiaying Sim 건국대학교 아시아·디아스포라 연구소 2020 International Journal of Diaspora&Cultural Critici Vol.10 No.1

This paper argues that in Singaporean director Yeo Siew Hua’s feature film, A Land Imagined (2019), liminal states of in-betweenness and blurred subjectivities in the film embody and uncover the precarious positions that transnational migrant workers occupy in Singapore. I posit that the only way to “find” the missing construction worker from China who disappears suddenly from a land reclamation site early in the film is to traverse and transgress spaces as defined by physical, national, psychological, real and/or technological boundaries. It is only through the act of tracing and attending to transsensorial states of trance presented in and produced within and without the film can the disembodied “ghost” of the missing migrant worker be returned to his body and hence the materiality of the film. The audience is compelled to ethically examine the strong presence of transmigrant labour that is forced to pass as invisible or absent in nation-state Singapore.

Methanobactin-Mediated One-Step Synthesis of Palladium Nanoparticles

Jiaying Xin,Hong-Chen Fan,Sheng-Fu Ji,Yan Wang,Chungu Xia 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.6

The development of palladium nanoparticles (PdNPs) with a narrow size distribution is an important aspect of nanotechnology. Methanobactin (Mb) is a copper-binding small peptide that appears to function as an agent for copper sequestration and uptake in methanotrophs. Here, Mb was shown to bind and catalytically reduce Pd (II) to Pd (0). The one-step synthesis of monodisperse PdNPs using Mb as both coordination agent and reduction agent is reported. Fluorescence spectra, UV-visible spectra, X-ray photoelectron spectroscopy (XPS) and Fourier transform-infrared spectroscopy (FT-IR) suggested that the Mb molecules catalytically reduce Pd (II) to Pd (0) with the concomitant production of PdNPs. The Mb is then adsorbed onto the surface of the PdNPs to form an Mb–PdNPs coordination compound. This avoids secondary nucleation. The PdNPs are small with high monodispersity and are easily synthesized in Mb solution. The PdNPs were extremely stable and resisted aggregation even after several months.

Simple

JiaYing Zhu 한국콘텐츠학회 2017 ICCC International Digital Design Invitation Exhib Vol.2017 No.8

Simple

JiaYing Zhu 한국콘텐츠학회 2017 ICCC International Digital Design Invitation Exhib Vol.2017 No.5

Splat‑boundary reinforcement induced by graphene in plasma‑sprayed hydroxyapatite composite coating

Jiaying Zhu,Jia Ren,Yao Chen 한국탄소학회 2019 Carbon Letters Vol.29 No.1

Plasma-sprayed HA coatings on metallic implants are widely used for clinical applications. However, typical lamellar structure along with plasma-sprayed coatings usually leads to weak inter-splat adhesion and impair their mechanical properties. In this research, graphene nanosheet (GNS) reinforced HA coatings were fabricated using plasma spray; these GNSs retained their original structure and distributed homogeneously in the as-sprayed coatings. On the basis of instrumented microindentation tests with and without multiple partial unloading, as compared with the monolithic HA coating, the inter-splat friction force increased by ~ 8.7% for the 1.0 wt% GNS/HA coating, and it slightly decreased to ~ 6.5% for the 2.0 wt% GNS/ HA coating due to GNS agglomeration. Meanwhile, the added GNSs contributed greatly to the indentation yield strength of the HA coatings. These results illustrated that these embedded GNSs at splat boundaries are potential in splat-boundary strengthening and resisting splat sliding.

Genome wide association study on feed conversion ratio using imputed sequence data in chickens

Jiaying Wang,Xiaolong Yuan,Shaopan Ye,Shuwen Huang,Yingting He,Hao Zhang,Jiaqi Li,Xiquan Zhang,Zhe Zhang 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.4

Objective: Feed consumption contributes a large percentage for total production costs in the poultry industry. Detecting genes associated with feeding traits will be of benefit to improve our understanding of the molecular determinants for feed efficiency. The objective of this study was to identify candidate genes associated with feed conversion ratio (FCR) via genome-wide association study (GWAS) using sequence data imputed from single nucleotide polymorphism (SNP) panel in a Chinese indigenous chicken population. Methods: A total of 435 Chinese indigenous chickens were phenotyped for FCR and were genotyped using a 600K SNP genotyping array. Twenty-four birds were selected for sequencing, and the 600K SNP panel data were imputed to whole sequence data with the 24 birds as the reference. The GWAS were performed with GEMMA software. Results: After quality control, 8,626,020 SNPs were used for sequence based GWAS, in which ten significant genomic regions were detected to be associated with FCR. Ten candidate genes, ubiquitin specific peptidase 44, leukotriene A4 hydrolase, ETS transcription factor, R-spondin 2, inhibitor of apoptosis protein 3, sosondowah ankyrin repeat domain family member D, calmodulin regulated spectrin associated protein family member 2, zinc finger and BTB domain containing 41, potassium sodium-activated channel subfamily T member 2, and member of RAS oncogene family were annotated. Several of them were within or near the reported FCR quantitative trait loci, and others were newly reported. Conclusion: Results from this study provide valuable prior information on chicken genomic breeding programs, and potentially improve our understanding of the molecular mechanism for feeding traits.

Enhancement of catalytic activity of lipase-immobilized Fe3O4-chitosan microsphere for enantioselective acetylation of racemic 1-phenylethylamine

Jiaying Pan,Zhimin Ou,Lan Tang,Hanbing Shi 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.5

Racemic 1-phenylethylamine was resolved by enantiomer selective acetylation using Fe3O4-chitosan microsphere (CTS)-glutaraldehyde-lipase in a solvent-free system under an alternating magnetic field. Magnetic chitosan microspheres (Fe3O4-CTS) were prepared via chemical co-precipitation and cross-linked with lipase using glutaraldehyde to form Fe3O4-CTS-glutaraldehyde-lipase particles. The magnetic, physicochemical, and textural characteristics of Fe3O4-CTS-glutaraldehyde-lipase particles were assessed by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The optimal immobilization conditions were 2.4mg/mL lipase, 10mg/mL Fe3O4- CTS-glutaraldehyde, pH 8.5, 35 oC, 3 h. The loading amount of lipase and the specific activity got to 132mg/g carrier and 48U/g. The optimal reaction conditions of the acylation reaction using Fe3O4-CTS-glutaraldehyde-lipase were 300mmol/L 1-phenylethylamine, 150mg immobilized lipase, 2mL vinyl acetate, 12.6 ×g rotating speed, 40 oC, 8 h. The activity of the Fe3O4-CTS-glutaraldehyde-lipase particles and conversion were improved when they were exposed to an external alternating magnetic field. The optimum magnetic field was 12 Gs (500 Hz). The conversion, enantiomeric excess of (R)-N-(1-phenylethyl)acetamide, and E value reached 41.8%, 98.4%, and 264, respectively. Fe3O4-CTS-glutaraldehyde- lipase could be reused seven times. A kinetic model of the immobilized lipase-catalyzed resolution of 1- phenylethylamine was set up based on the ping-pong bi–bi mechanism. The kinetic constants were Vmax=1.62×102 mM/min, KA=2.84×104mM, and KB=5.8×101mM. The model data fit well with the experimental data.

Embodied ways of Be(coming) With Me: Cinematic Affectivity and Sensoriality

Jiaying SIM 한국비평이론학회 2016 한국비평이론학회 학술대회 발표집 Vol.2016 No.봄

Effect of nano MMT and mesoporous MCM-41 on corrosion resistance of poly (propylene carbonate) - based waterborne polyurethane

Jiaying Zhang,Hui Zheng,Haibo Geng,Ying Li,Yapeng Guan,Yuanbin Sun,Cunjian Zhu 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.4

Environmental friendly poly (propylene carbonate)-based waterborne polyurethane (PPC-based WPU) isprepared with PPC and isophorone diisocyanate (IPDI) as the soft segment and the hard segment, respectively. In thisreaction system, 2,2-dimethylolbutyric acid (DMBA) is used as the hydrophilic donor and trimethylolpropane (TMP)as the crosslinking agent. The effect of co-doping of layered montmorillonite (MMT) and mesoporous material MCM-41 on corrosion resistance of PPC-based WPU resin was studied. The properties of the samples were characterizedwith N2 physical adsorption, XRD, FT-IR, TG-DTA, DSC and water absorption testing. Potentiodynamic polarizationcurves, electrochemical impedance spectroscopy (EIS) and salt spray test were employed to investigate the corrosionperformance of all the coatings. The results of XRD indicate that the MMT in the composite polyurethane resin ispeeled off and MCM-41 maintains the hexagonal framework structure after grinding. Compared with the WPU coatingswith MMT or MCM-41 single incorporation, those with MMT and MCM-41 co-incorporation show the best corrosionresistance, which is due to the different interface structure between filler and resin matrix.