19 results on '"Chen, Hong‐Yuan"'
Search Results
2. Polygonatum binatifolium S. R. Yi et H. X. Zhu Stem Stem 2022, sp. nov
- Author
-
Zhu, Heng-Xing, Huang, Fei-Yi, Chen, Hong-Yuan, Zhang, Hong-Jing, Dai, Qian-Li, and Yi, Si-Rong
- Subjects
Polygonatum binatifolium ,Tracheophyta ,Liliopsida ,Polygonatum ,Asparagales ,Biodiversity ,Plantae ,Taxonomy ,Asparagaceae - Abstract
Polygonatum binatifolium S.R. Yi et H.X. Zhu, sp. nov. (Figs. 1–2) Diagnosis:—The new species is most similar to Polygonatum cyrtonema Hua, but differs by its shorter stem (20–50 cm vs. 50–100 cm), much smaller leaves (4–8 × 2.4–4.5 cm vs. 10–18 × 2–7 cm) and lowest two opposite (vs. alternate), perianth 8–12 mm long (vs. 1.8–2.5 cm), filaments ca. 1.0 mm long (vs. 3–4 mm), ovary 1.8–2.2 mm in diam. (vs. 3–6 mm), style 1.5–2.0 mm long (vs. 1.2–1.5 cm), berry red (vs. black) and 5.5–6.5 mm in diam. (vs. 6-12 mm), seed pale yellow (vs. yellowish-white), 2.4–3.0 × 2.0– 2.4 mm (vs. 3.8–5.6 × 2.8–3.6 mm) (Table 1). Type:— CHINA. Guizhou: Yinjiang County, Mt. Fanjing, N27°54′43″, E108°39′37″, elev. 2, 014 m, on the mossy rocks or tree trunks under forests, 22 May 2020, S.R. Yi 8547 (holotype, KUN; isotype, KUN). Perennial herbs, up to 50 cm tall, rhizome tuberous, with many rings, upper tip with hollow round stalk scars. Rhizome 1.5–3.0 cm in diam., with most fibrous roots up to 30 cm long. Stem green, sparsely short glandular hairs, purple pinstripes bottom node, 2.5–4.5 mm in diam.. Two bottom leaves opposite, upper leaves alternate; leaf blade oblongovate to oblong-lanceolate, 4.0–8.0 × 2.4–4.5 cm, with 5–7 veins, adaxially dark green, abaxially pale green, glabrous both sides, apex rounded and obtuse, base broadly cuneate, descending to petiole; petioles 3.0–5.0 mm long, base half clasped; midrib adaxially concave, abaxially raised. Inflorescence axillary with 2–5 flowers or 1–2 flowers no peduncles, peduncles 5.0–8.0 mm long, lower flattened, up to 3.0 mm wide, pedicels rounded, 8–15 mm long, peduncles and pedicels smooth and glabrous; bracts absent. Flowers yellow-green, 8–12 mm long, tube 4.0–5.0 mm in diam., crown 5.0–6.0 mm in diam., tube 5.0–6.0 mm long; inner lobes broadly ovate, 3.4–3.8 ×3.0–4.0 mm, apex obtuse, suberect; outer lobes narrowly ovate-lanceolate, 2.4–2.7 × 3.0–4.0 mm, apex short pointed, volume; perianth lobes all with a pale green midrib. Stamens inserted near middle of corolla tube, filaments very short, ca. 1.0 mm long, anthers arrowhead, 1.6–1.9 mm long. Pistil smooth and glabrous, ovary alar, 1.8–2.2 mm in diam., 2.5–3.0 mm high, style 1.5–2.0 mm long, stigma capitate. Berries globose, red, 5.5–6.5 mm in diam., 3-loculed, 1–3-seeded per locule; seeds ovoid, pale yellow, slightly flattened, 2.4–3.0 ×2.0– 2.4 mm. Distribution and habitat: —According to present collections, Polygonatum binatifolium was only known from two localities in Guizhou province, i.e., Mt. Fanjing, Yinjiang and Woyangqing, Panzhou. This rare species grows on mossy rocks or tree trunks under forests between 1,900 m and 2, 100 m at elevation. It is considered as Critically Endangered (CR) according to current information and the IUCN Red List criteria (IUCN, 2019) because it is only found in the area of less than 5 km 2 in Yinjiang and Panzhou. Future fieldwork may expand its distribution area and habitat. Phenology: —Flowering time is between April and May; fruiting time from September to October. Etymology: —The specific epithet refers to the opposite state of the lowemost two leaves. The Chinese name is given as “ 基对叶fiffl ”. Additional specimens examined (paratypes): — CHINA. Guizhou: Panzhou, Woyangqing, N25°59′5″, E104°51′3″, elev. 1, 935 m, on mossy rocks under forests, 24 May 2020, S.R. Yi 8561 (KUN); Panzhou, Woyangqing, N25°59′5″, E104°51′3″, elev. 1, 935 m, on mossy rocks under forests, 16 September 2021, S.R. Yi 9267 (KUN); Yinjiang County, Mt. Fanjing, N27°54′43″, E108°39′37″, elev. 2, 014 m, on the mossy rocks under forests, 9 October 2021, S.R. Yi 9308 (KUN); Panzhou, Yangmazhai [maybe not the real location], N25°58′40.9″, E104°53′44.7″, in the grass, elev. 1, 619 m, 11 July 2014, Ping-zhong Qu 520222140711007LY (GZTM0045437, GZTM0045438)., Published as part of Zhu, Heng-Xing, Huang, Fei-Yi, Chen, Hong-Yuan, Zhang, Hong-Jing, Dai, Qian-Li & Yi, Si-Rong, 2022, Polygonatum binatifolium, a new species of Polygonatum (Asparagaceae) from Guizhou, China, pp. 247-252 in Phytotaxa 549 (2) on pages 248-251, DOI: 10.11646/phytotaxa.549.2.11, http://zenodo.org/record/6622718, {"references":["IUCN Standards and Petitions Committee. (2019) Guidelines for Using the IUCN Red List Categories and Criteria (Version 14). Prepared by the Standards and Petitions Committee, pp. 9 - 16. [http: // www. iucnredlist. org / documents / RedListGuidelines. pdf]"]}
- Published
- 2022
- Full Text
- View/download PDF
3. Effect of Strain Aging on Properties of X90 Line Pipe
- Author
-
Feng Hui, Chen Hong-yuan, Ji Lingkang, Ben Yu-zhuang, Li Yan-hua, and Chi Qiang
- Subjects
Materials science ,Impact toughness ,Sensitivity coefficient ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Microstructure ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Ultimate tensile strength ,Yield ratio ,Composite material ,0210 nano-technology ,Dynamic strain aging ,Earth-Surface Processes ,Line (formation) - Abstract
Tensile and impact toughness test on X90 line pipe with different aging conditions were conducted to study the effect of aging conditions on properties of X90 pipeline steel. The result shows that yield strength and yield ratio of X90 line pipe would increase significantly with the introduction of strain aging, while the impact toughness and tensile strength have little change. The impact toughness of X90 line pipe would decrease with the introduction of 200℃, 5min aging. However, the impact toughness of X90 pipeline would increase with the increase of aging temperature and aging time (250 ℃, 1h). The tensile strength of X90 pipeline steel would decrease or increase slightly after the introduction of aging. While the yield strength and yield ratio would increase significantly after the introduction of aging, and the rising range of yield strength and yield ratio would decrease with he increase of aging temperature and aging time. Comprehensive analysis shows that the aging treatment have different effects on different X90 pipeline steel, mainly due to different microstructure and chemical composition of X90 pipeline between manufacturers during the trial production. The result of aging sensitive coefficient analysis shows that the effect of microstructure type is more significant than that of chemical composition, and X90 pipeline steel with dual-phase microstructure would has high aging sensitivity coefficient.
- Published
- 2019
4. FAILURE ANALYSIS OF A STRESS-BASED PIPELINE UNDER PLASTIC STRAIN
- Author
-
Feng Hui, Chen Hong-yuan, Chi Qiang, and Huo Chun-yong
- Subjects
Stress (mechanics) ,Pipeline (computing) ,Geotechnical engineering ,Plasticity ,Geology - Published
- 2020
5. Electrode-free nanopore sensing by DiffusiOptoPhysiology
- Author
-
Wang, Yuqin, Wang, Yu, Du, Xiaoyu, Yan, Shuanghong, Zhang, Panke, Chen, Hong-Yuan, and Huang, Shuo
- Subjects
Fluorescence-lifetime imaging microscopy ,Materials science ,Sensing applications ,Biophysics ,Nanotechnology ,Biosensing Techniques ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Multiplexing ,Nanopores ,Research Methods ,Electrodes ,Research Articles ,Multidisciplinary ,SciAdv r-articles ,021001 nanoscience & nanotechnology ,Chip ,0104 chemical sciences ,Nanopore ,Applied Sciences and Engineering ,Clinical diagnosis ,Electrode ,Nanopore sequencing ,0210 nano-technology ,Research Article - Abstract
Microscopic imaging methods facilitate single-molecule nanopore sensing without the need of electronic connections., A wide variety of single molecules can be identified by nanopore sensing. However, all reported nanopore sensing applications result from the same measurement configuration adapted from electrophysiology. Although urgently needed in commercial nanopore sequencing, parallel electrophysiology recording is limited in its cost and its throughput due to the introduced complexities from electronic integration. We present the first electrode-free nanopore sensing method defined as DiffusiOptoPhysiology (DOP), in which single-molecule events are monitored optically without any electrical connections. Single-molecule sensing of small molecules, macromolecules, and biomacromolecules was subsequently demonstrated. As a further extension, a fingertip-sized, multiplexed chip with single-molecule sensing capabilities has been introduced, which suggests a new concept of clinical diagnosis using disposable nanopore sensors. DOP, which is universally compatible with all types of channels and a variety of fluorescence imaging platforms, may benefit diverse areas such as nanopore sequencing, drug screening, and channel protein investigations.
- Published
- 2019
6. Antifungal Effect of Magnolol and Honokiol from
- Author
-
Ya-Han, Chen, Mei-Huan, Lu, Dong-Sheng, Guo, Ying-Yan, Zhai, Dan, Miao, Jian-Ying, Yue, Chen-Hong, Yuan, Ming-Min, Zhao, and De-Rong, An
- Subjects
Antifungal Agents ,Biphenyl Compounds ,antifungal activity ,food and beverages ,Alternaria ,magnolol ,Lignans ,Article ,honokiol ,Magnolia ,Tobacco ,Alternaria alternata ,Magnolia officinalis ,Plant Diseases - Abstract
In this study, two phenol compounds, magnolol and honokiol, were extracted from Magnolia officinalis and identified by LC-MS, 1H- and 13C-NMR. The magnolol and honokiol were shown to be effective against seven pathogenic fungi, including Alternaria alternata (Fr.) Keissl, Penicillium expansum (Link) Thom, Alternaria dauci f.sp. solani, Fusarium moniliforme J. Sheld, Fusarium oxysporum Schltdl., Valsa mali Miyabe & G. Yamada, and Rhizoctonia solani J.G. Kühn, with growth inhibition of more than 57%. We also investigated the mechanisms underlying the potential antifungal activity of magnolol and honokiol. The results showed that they inhibited the growth of A. alternata in a dose-dependent manner. Moreover, magnolol and honokiol treatment resulted in distorted mycelia and increased the cell membrane permeability of A. alternata, as determined by conductivity measurements. These results suggest that magnolol and honokiol are potential antifungal agents for application against plant fungal diseases.
- Published
- 2019
7. Transient microscopy for measuring heat transfer in single cells
- Author
-
Song, Pei, Gao, He, Zhang, Miao, Yang, Fan, Li, Shan-Shan, Kang, Bin, Xu, Jing-Juan, and Chen, Hong-Yuan
- Subjects
Biological Physics (physics.bio-ph) ,FOS: Physical sciences ,Physics - Biological Physics ,Physics - Applied Physics ,Applied Physics (physics.app-ph) - Abstract
Heat transfer and dissipation exists in almost any physical, chemical or biological systems. Cells, as the basic unit of life, undergo continuous heat transfer and dissipation during their metabolism. The heat transfer and dissipation within cells related to not only fundamental cellular functions and biochemical reactions, but also several important applications including heat-induced control of biological processes and treatment of diseases. Unfortunately, thus far, we still know very little about the heat transfer and dissipation properties at cellular or subcellular level. Here, we demonstrated a methodology of transient microscopy to map the heat transfer coefficients in single cells, with a temporal resolution of ~5 us and a spatial resolution of ~250 nm (close to diffraction limit). The heat transfer coefficients of different location within single cells were obtained for the first time, the inner part of cells exhibited nonuniform heat transfer properties, and it suggested a self-consistent heat transfer regulation that responds to environmental temperature., Comment: 14 pages, 4 figures
- Published
- 2019
- Full Text
- View/download PDF
8. Mass transport in nanofluidic devices
- Author
-
Xia Xing-hua, Xu Jing-Juan, Chen Hong-Yuan, and Wang Chen
- Subjects
chemistry.chemical_classification ,Biomolecule ,Microfluidics ,Nanotechnology ,Nanofluidics ,General Chemistry ,Electrokinetic phenomena ,symbols.namesake ,chemistry ,Rectification ,symbols ,Surface charge ,Debye length ,Concentration polarization - Abstract
Nanofluidics is a recent appearing research field, introduced in 1995 as an analogue of the field of microfluidics, and has been becoming popular in the past few years. The proximity of the channel dimension, the Debye length, and the size of biomolecules such as DNA and proteins gives the unique features of nanofluidic devices. Of various unique properties of the nanofluidics, mass transport in nanochannel plays determining roles in fundamental reaches and practical applications of nanofluidic device. Thus, much work including numerical and experimental researches has been performed to investigate the mass transport behaviors in nanofluidic devices. This review summarizes the fabrication technologies for nanofluidic devices, the mass transport behaviors in nanochannel, and their applications in bioanalysis. The main focus will be laid on the effects of nanochannel size and surface charge on mass transport including electrokinetic transport of charged analytes, diffusion of electric neutral molecules, ionic current rectification, concentration polarization, nonlinear electrokinetic flow at the micro-nanofluidic interfaces.
- Published
- 2012
9. An improved ELISA for the determination of southern bean mosaic virus with linear sweep voltammetry detection based on new system of PAP-H2O2-HRP
- Author
-
Zhang Cheng-Liang, Zhang Shu-Sheng, Zhang Zuo-Fang, Jiao Kui, and Chen Hong-Yuan
- Subjects
Detection limit ,Chromatography ,biology ,Chemistry ,Analytical chemistry ,food and beverages ,General Chemistry ,Buffer solution ,Horseradish peroxidase ,chemistry.chemical_compound ,Linear range ,Southern bean mosaic virus ,Linear sweep voltammetry ,biology.protein ,Tobacco mosaic virus ,Voltammetry - Abstract
An improved ELISA for the determination of tobacco mosaic virus (TMV) with linear sweep voltammetry based on a new system of p-aminophenol (PAP)- H2O2- horseradish peroxidase (HRP) has been developed. The enzymatic product 3-[(4-hydroxyphenyl)amino]-4-(2-amino-5-hydroxyphenyl)-6-[(4-hydroxyphenyl)imino]-2,4-cyclohexadiene-1-one, produced from HRP catalyzing the oxidation of PAP with H2O2, yields a sensitive linear sweep voltammetric response at a potential of –0.45 V (vs. SCE) in Britton-Robinson (BR) buffer solution. By using this voltammetric peak, HRP can be measured with a detection limit of 0.4 mU/L and a linear range of 1.0 ∼ 1.0 × 102 mU/ L. The detection limit for the clarified TMV is 4.0 ng/mL and the highest dilution ratio detected for the infected leaf sap is 1 : 3.9 × 106. The processes of the enzyme-catalyzed reaction and the electro-reduction of the product of the enzyme-catalyzed reaction have been investigated.
- Published
- 2010
10. Direct Electron Transfer between Glucose Oxidase and Multi-walled Carbon Nanotubes
- Author
-
Chen Hong-Yuan, Hu Zheng, Xu Jin-Zhong, Wu Qiang, and Zhu Jun-Jie
- Subjects
biology ,Chemistry ,General Chemistry ,Carbon nanotube ,Surface reaction ,Electrochemistry ,humanities ,law.invention ,Electron transfer ,Chemical engineering ,law ,biology.protein ,Organic chemistry ,Glucose oxidase - Abstract
The direct electrochemical behavior between the glucose oxidase (GOD) and the multi-walled carbon nanotubes (MWNTs) has been studied. Two pairs of cyclic voltammetric peaks corresponding to the two different processes, i.e. mass-transport and surface reaction of GOD are observed on this MWNTs. The formal potentials with Eo' =-0.45 V and Eo' =-0.55 V were obtained respectively. The GOD film was observed on the carbon nanotube by the TEM.
- Published
- 2010
11. Direct Electrochemistry of Horseradish Peroxidase Immobilized on a Colloid/Cysteamine-Modified Gold Electrode
- Author
-
Chen Hong-Yuan, Ju Huang-Xian, and Xiao Yi
- Subjects
Cysteamine ,Biophysics ,Analytical chemistry ,Biosensing Techniques ,Electrochemistry ,Biochemistry ,Redox ,Horseradish peroxidase ,Electron Transport ,Gold Colloid ,Colloid ,Electron transfer ,chemistry.chemical_compound ,Colloids ,Electrodes ,Molecular Biology ,Horseradish Peroxidase ,biology ,Chemistry ,Hydrogen Peroxide ,Cell Biology ,Enzymes, Immobilized ,Electrode ,biology.protein ,Gold ,Nuclear chemistry - Abstract
Direct electron transfer of immobilized horseradish peroxidase on gold colloid and its application as a biosensor were investigated by using electrochemical methods. The Au colloids were associated with a cysteamine monolayer on the gold electrode surface. A pair of redox peaks attributed to the direct redox reaction of horseradish peroxidase (HRP) were observed at the HRP/Au colloid/cysteamine-modified electrode in 0.1 M phosphate buffer (pH 7.0). The surface coverage of HRP immobilized on Au colloid was about 7.6 x 10(-10) mol/cm(2). The sensor displayed an excellent electrocatalytic response to the reduction of H(2)O(2) without the aid of an electron mediator. The calibration range of H(2)O(2) was 1. 4 microM to 9.2 mM with good linear relation from 1.4 microM to 2.8 mM. A detection limit of 0.58 microM was estimated at a signal-to-noise ratio of 3. The sensor showed good reproducibility for the determination of H(2)O(2). The variation coefficients were 3. 1 and 3.9% (n = 10) at 46 microM and 2.8 mM H(2)O(2), respectively. The response showed a Michaelis-Menten behavior at higher H(2)O(2) concentrations. The K(app)(M) value for the H(2)O(2) sensor was found to be 2.3 mM.
- Published
- 2000
12. Fast Image Blending and Deghosting for Panoramic Video
- Author
-
Jeng-Shyang Pan, Ming-Hwa Sheu, Tzu-Hsiung Chen, and Chen-Hong Yuan
- Subjects
Matching (graph theory) ,business.industry ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Process (computing) ,Image subtraction ,Monitoring system ,Image (mathematics) ,Image stitching ,Homography ,Computer vision ,Artificial intelligence ,Ghosting ,business ,ComputingMethodologies_COMPUTERGRAPHICS ,Mathematics - Abstract
The technology of panoramic image construction is widely used in many conditions. As the increasingly demand of monitoring system application, the attribute of real-time is more important during the panoramic construction. This paper describes a method of fast building panoramic video and output frames in real-time. SURF algorithm is employed to extract features and a new method is developed to eliminate matching mistakes in this work. As traditional transform method use only one homography matrix, the stitch error in detail is obvious. In this paper the modified dual-homography is proposed to improve the stitch performance. Ghosting effect is a universal problem in image stitching and difficult to avoid. This topic use image subtraction and smooth transition blending method to avoid ghost. Since this topic skips the seam finding process, so the time consumption is low and the method can achieve real-time requirement.
- Published
- 2013
13. The electrochemical polymerization of methylene green and its electrocatalysis for the oxidation of NADH
- Author
-
Wang Yun, Ju Huang-Xian, Fang Hui-Qun, Zhou Dong-mei, and Chen Hong-Yuan
- Subjects
Aqueous solution ,Inorganic chemistry ,Methylene green ,Overpotential ,Glassy carbon ,Electrochemistry ,Electrocatalyst ,Biochemistry ,Analytical Chemistry ,chemistry.chemical_compound ,Polymerization ,chemistry ,Electrode ,Environmental Chemistry ,Spectroscopy - Abstract
A poly(methylene green) thin film modified electrode was successfully prepared by means of electrochemical polymerization, which was carried out with cyclic voltammetric sweeps between −0.4 and +1.2 V (vs. SCE) at a glassy carbon base electrode in methylene green aqueous solution. The pH value of the solution notably affected the process of polymerization and the characteristics of the film. Compared with modified electrodes obtained by adsorption of methylene green in aqueous solution, this polymer modified electrode exhibited a higher stability and better catalytic activity for NADH. The peak potential shifted towards a positive direction for about 180mV in neutral medium. An obvious catalytic current could be observed for the oxidation of NADH, moreover, the polymer could reduce the oxidation overpotential of NADH by about 400 mV. The electrocatalytic current was proportional to the concentration of NADH, and a good linear relation from 0.5 to 10.0 mM with a correlation coefficient of 0.996 was obtained.
- Published
- 1996
14. The application of the concept of the steady-state reaction—diffusion layer to a study of the electrode processes with multistep reactions at microelectrodes under steady-state conditions
- Author
-
Zhuang Qiankun and Chen Hong-Yuan
- Subjects
Microelectrode ,Electron transfer ,Chemistry ,General Chemical Engineering ,Diffusion ,Reaction–diffusion system ,Electrode ,Electrochemistry ,Physical chemistry ,Steady state (chemistry) ,Rotating disk electrode ,Analytical Chemistry - Abstract
pUnder steady-state conditions, the general current equations for the first-order or pseudo-first-order EC, EC′, ECE and DISP1 reactions and the second-order EC′ reactions at a spherical microelectrode are derived with the aid of the concept of the steady-state reaction—diffusion layer. The approach relies on the analogy between a spherical microelectrode and a rotating-disk electrode. The characteristics of the E r C, E q C, E i C, E r C′, E q C′, E i C′, E r CE r , E r CE q , E r CE i , E q CE r and DISP1 mechanisms, where the electron transfer reaction is reversible, quasi-reversible or irreversible, are also discussed. Using these equations, some methods of determining kinetic parameters for the EC, EC′, ECE and DISP1 reactions are presented.
- Published
- 1993
15. Investigation on microelectrodes
- Author
-
Gao Hong, Ju Huang-Xian, and Chen Hong-Yuan
- Subjects
Electrolysis ,Physics::Instrumentation and Detectors ,Chemistry ,General Chemical Engineering ,Molecular physics ,Analytical Chemistry ,law.invention ,Diffusion layer ,Microelectrode ,Nuclear magnetic resonance ,Physics::Plasma Physics ,law ,Electromagnetic shielding ,Electrode ,Electrochemistry ,Shielding effect ,Diffusion current ,Diffusion (business) - Abstract
Microband electrodes display a very strong edge effect. The diffusion layer at a microband electrode may be considered as a semicylinder. When a microband-array electrode is electrolysed for a long time, these diffusion layers partially overlap each other and the total current is smaller than the sum of the currents at all single-microband electrodes. This is the so-called shielding effect. The degree of shielding can be expressed by a shielding factor Sf which depends on the electrolysis time, the distance between electrodes and the electrode width. A formula to calculate the shielding factor Sf is presented here. The results of theoretical calculations are found to be in good agreement with experimental results reported previously.
- Published
- 1992
16. Amperometric glucose sensor based on coimmobilization of glucose oxidase and Poly(p-phenylenediamine) at a platinum microdisk electrode
- Author
-
Xu Jing-Juan and Chen Hong-Yuan
- Subjects
Polymers ,Biophysics ,Analytical chemistry ,chemistry.chemical_element ,Biosensing Techniques ,Phenylenediamines ,Biochemistry ,Michaelis–Menten kinetics ,Glucose Oxidase ,Electrochemistry ,Polyamines ,Glucose oxidase ,Molecular Biology ,Platinum ,biology ,Cell Biology ,Ascorbic acid ,Amperometry ,Microelectrode ,Glucose ,chemistry ,Linear range ,biology.protein ,Aspergillus niger ,Biosensor ,Microelectrodes ,Nuclear chemistry - Abstract
A miniaturized glucose biosensor in which glucose oxidase (GOD) and poly(p-phenylenediamine) (poly-PPD) were coimmobilized at the surface of a platinum microdisk electrode was developed and used successfully for amperometric determination of glucose. The performance of sensors prepared at different monomer concentrations and polymerization potentials with different media was investigated in detail. It was found that similarly to poly(o-phenylenediamine) (poly-OPD), (poly-PPD) noticeably eliminated the electrochemical interference of ascorbic acid, uric acid, and l-cysteine. The amperometric response of glucose with the biosensor under optimal conditions exhibited a linear relationship in the range of 5.0 x 10(-5) to 3.0 x 10(-3) M with correlation coefficient 0.9995. According to the Michaelis-Menten equation, the apparent Michaelis constant for glucose and the maximum steady-state current density of the poly-PPD/GOD-modified microelectrode were 3.94 mM and 607.5 microA cm(-2), respectively. The current density of the sensor responding to glucose in the linear range can reach 160 microA cm(-2) mM(-1), which is far greater than that obtained using poly-OPD and poly(phenol) film. In addition, the stability of the sensor was examined over a 2-month period.
- Published
- 2000
17. Determination of hydroquinone and metal in photographic developer by reversed-phase ion-pair chromatography with amperometric detection
- Author
-
Rolf Neeb, Zou Gongwei, Xie Xiaomei, Shi Rongrong, and Chen Hong-Yuan
- Subjects
Chromatography ,Hydroquinone ,Chemistry ,Sodium ,Ion chromatography ,chemistry.chemical_element ,Reversed-phase chromatography ,Biochemistry ,Amperometry ,Photographic developer ,Analytical Chemistry ,Metal ,chemistry.chemical_compound ,visual_art ,Reagent ,visual_art.visual_art_medium ,Environmental Chemistry ,Spectroscopy - Abstract
Sodium 1-heptanesulphonate is used as an ion-pair reagent for the chromatographic separation of the two developing agents on a phenylsilica micro-column, with amperometric detection at an applied potential of + 0.75 V (vs. Ag/AgCl). No pretreatment of the developer is necessary. Linear calibration graphs were obtained in the range 10 −5 -1.5 × 10 −4 M.
- Published
- 1988
18. Electrocatalytic oxidation and flow detection of NAD(P)H at a histidine modified silver electrode
- Author
-
Long Yi-Tao, Zou Jie, and Chen Hong-Yuan
- Subjects
Detection limit ,medicine.medical_specialty ,biology ,Chemistry ,Biochemistry (medical) ,Clinical Biochemistry ,Inorganic chemistry ,Electrochemistry ,Biochemistry ,Amperometry ,Cofactor ,Analytical Chemistry ,Bioelectrochemistry ,Electrode ,medicine ,biology.protein ,NAD+ kinase ,Cyclic voltammetry ,Spectroscopy - Abstract
L-Histidine, a biologically important amino acid, has been modified onto the silver electrode through covalent bonding. The coenzyme dihydronicotinamide adenine dinucleotide (NAD(P)H) was electrocatalytically oxidized to NAD(P)+ at a L-histidine modified silver electrode (His/Ag). The electrochemical processes at the His/Ag electrode were investigated by using UV-visible spectroelectrochemistry in detail. Amperometric determination of NAD(P)H, at a potential of 0.25V (SCE), gave a linear response in the range of 1 × 10−7∼2 × 10−5 mol/L with a detection limit of 0.05 μmol/L. The His/Ag electrode has been used in a FIA system with satisfactory results. Meanwhile, other proteins and chemicals present in samples do not interfere in the assay.
19. Nanopore Sequencing Accurately Identifies the Mutagenic DNA Lesion O; 6; -Carboxymethyl Guanine and Reveals Its Behavior in Replication
- Author
-
Wang, Yu, Patil, Kiran M., Yan, Shuanghong, Zhang, Panke, Guo, Weiming, Wang, Yuqin, Chen, Hong-Yuan, Gillingham, Dennis, and Huang, Shuo
- Subjects
3. Good health
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.