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Search Results: 1 - 10 of 18905 matches for " Zhenghua Song "
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Ultrasensitive determination of amoxicillin using chemiluminescence with flow injection analysis
Xiaofeng Xie,Zhenghua Song
Spectroscopy: An International Journal , 2006, DOI: 10.1155/2006/270417
Abstract: Results presented here reveal that amoxicillin can greatly enhance the chemiluminescence intensity generated from the reaction between luminol and hydrogen peroxide. The increment chemiluminescence signal was linearly dependent on amoxicillin concentration in the range from 10 pg·ml?1 to 2 ng·ml?1 (r2=0.9978) offering a detection limit as low as 3.5 pg·ml?1 (3σ). At a flow rate of 2.0 ml·min?1, one analysis cycle, including sampling and washing, can be accomplished in 20 s with a relative standard deviation of less than 5%. The sensitive flow injection method was applied successfully to determine of amoxicillin in pharmaceutical preparations, human urine and serum without any pretreatment procedure, with recovery from 90.0% to 110.0% and relative standard deviations of less than 5.0%.
Determination of Nanogram Quantities of Emodin in Pharmaceutical Preparations and Biofluids by Luminol-Myoglobin Chemiluminescence System
Yun Zhang,Xili He,Zhenghua Song
Spectroscopy: An International Journal , 2012, DOI: 10.1155/2012/741053
Abstract: Based on the quenching effect of emodin on the luminol-myoglobin (Mb) reaction, a sensitive method for the determination of nanogram level emodin by flow injection chemiluminescence (FI-CL) is presented for the first time. It was found that the CL intensity from luminol-Mb system could be inhibited in the presence of emodin, and the decrement of CL intensity was linearly proportional to the logarithm of emodin concentration in the range of 0.5–300ng?mL?1 (R = 0.9956) with the detection limit of 0.2ng?mL?1 (3σ). At a flow rate of 2.0mL?min?1, a complete determination of emodin, including sampling and washing, could be accomplished in 0.5 min with the relative standard deviations (RSDs) of less than 3.5% (n = 5). The proposed method was successfully applied to the determination of emodin in pharmaceutical preparations and human serum samples. The possible CL mechanism of luminol-Mb-emodin reaction was explained.
Comparison of Uric Acid Quantity with Different Food in Human Urine by Flow Injection Chemiluminescence Analysis
Jiajia Wang,Xijuan Tan,Zhenghua Song
Journal of Analytical Methods in Chemistry , 2013, DOI: 10.1155/2013/854041
Abstract: Based on the inhibitory effect of uric acid (UA) on luminol-Co2+ chemiluminescence (CL) system, a sensitive method for the determination of UA at nanomolar level by flow injection (FI) CL was proposed. The proposed method was successfully applied to real-time monitoring of UA excretion in human 24?h urine with different food intake, showing that meats, vegetables, and porridge intake caused differential UA excretions of 879, 798, and 742?mg, respectively. It was also found that UA concentrations in urine under the three kinds of food intake simultaneously reached maximum at 2?h after meals with the values of 417, 318, and 288? g?mL?1, respectively. The UA concentration in human serum was also determined by this approach, and the possible mechanism of luminol-Co2+-UA?CL reaction was discussed in detail. 1. Introduction Uric acid (2,6,8-trihydroxypurine, UA, Figure 1), the principal breakdown product of human purine metabolism, is mainly excreted by the kidney [1]. Normally, most of UA produced from the catabolism is reabsorbed into the blood circulation system and then passes through the kidney into urine. When UA in human urine or serum exceeds the normal physiological range, it may cause gout [2], kidney injury [3], metabolic syndrome [4], cardiovascular disease [5], and type II diabetes [6]. Consequently, monitoring the concentration of UA in bodily fluids is essential in diagnosis and treatment of the corresponding diseases. Many methods have been reported for the determination of UA, such as capillary electrophoresis (CE) [7], enzymatic assay (EA) [8], high-performance liquid chromatography (HPLC) [9, 10], differential pulse voltammetric (DPV) [11, 12], and UV-Vis spectroscopy [13, 14]. Chemiluminescence (CL) has also been developed for UA determination [15–17]. Figure 1: Chemical structure of UA. Luminol with Co2+ reaction is known as a classic CL system [18]. The CL mechanism of Co2+ remarkably enhancing luminol intensity has been well studied [19, 20], and a variety of applications with luminol-Co2+ CL system in trace analysis [21, 22] have been reported. For example, it has been applied to the determination of hydrogen peroxide [23, 24], acetaminophen [25], lanthanides [26], carbaryl [27], captopril [28], vitamin B12 [29], gibberellic acid [30], and radical scavenging potential of ascorbic acid [31]. With luminol-H2O2-Co2+ CL system, the determination of UA have been reported [32], while no real-time analysis of urine UA excretion with luminol-Co2+ CL system has been described so far. Flow injection (FI) analysis combined with CL, FI-CL, which
Determination of the Binding Parameters between Proteins and Luminol by Chemiluminescence Using Flow Injection Technique
Jie Guo,Donghua Chen,Zhenghua Song
ISRN Analytical Chemistry , 2013, DOI: 10.1155/2013/391053
Abstract: The interaction behavior of bovine serum albumin (BSA), lysozyme (LYS), myoglobin (MB), and catalase (CAT) with luminol, respectively, was first studied by chemiluminescence (CL) using flow injection (FI) technique based on the fact that the studied proteins can enhance the CL intensity of luminol. A FI-CL model of protein-luminol interaction, , was constructed, and the interaction parameters of BSA, LYS, MB, and CAT with luminol were determined accordingly. The binding constants are in the descending order of CAT > MB > LYS > BSA at the level of 105 to 107?L?mol?1, and the number of binding sites of luminol to BSA or LYS is around 2 and to MB or CAT is around 1. The results of thermodynamic parameters ( , , and ) showed that the binding processes of luminol to the four proteins are spontaneous mainly through the hydrophobic force. 1. Introduction Proteins possess many biological functions including binding, catalysis, operating as molecular switches, and serving as structural components of cells and organisms [1, 2] and play an important role in the transportation and deposition of various endogenous and exogenous substances [3, 4]. In recent years, the interaction of protein with small molecules has become a hot spot in the fields of chemistry, biology, and medicine [5–7]. As common model proteins, bovine serum albumin (BSA) [8], lysozyme (LYS) [9], myoglobin (MB) [10], and catalase (CAT) [11] are widely applied to the study of protein-small molecule interaction. Accordingly, many methods have been utilized to investigate this hot topic, such as fluorescence spectroscopy [12], resonance light scattering [13], circular dichroism [14], nuclear magnetic resonance spectroscopy [15], and chemiluminescence (CL) with flow injection (FI) technique [16]. The FI-CL analysis has proven to be a very useful analytical method with advantages of simple apparatus, high sensitivity, wide dynamic ranges, reproducibility, automatability, less reagent consumption [17–19], and so forth. Luminol (5-amino-2, 3-dihydro-1, 4-phthalazinedione) is known to produce CL with the characteristic wavelength of 425?nm under alkaline condition [20, 21], making it widely used around the world as a blood enhancement technique in forensic science. Also this luminescent compound is used clinically in the treatment of alopecia [22], the promotion of blood clotting [23], and wound healing [24]. Due to its high quantum yield, the CL of luminol has been used in many laboratory applications, including environmental field of analyzing trace metals [25, 26], food safety field [27], biological
Flow injection chemiluminescence determination of levofloxacin in medicine and biological fluids based on its enhancing effect on luminol–H2O2 reaction
Xiaodong Shao,Ying Li,Yangqin Liu,Zhenghua Song
Spectroscopy: An International Journal , 2009, DOI: 10.3233/spe-2009-0379
Abstract: Levofloxacin{(–)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid} is a synthetic fluorinated quinolone derivative, having activity against both Gram (+) and Gram (–) bacteria (aerobic and anaerobic) through inhibition of their DNA gyrase. In this paper, a simple flow injection chemiluminescence with luminol–hydrogen peroxide system was described for determining levofloxacin. The chemiluminescence intensity in the presence of levofloxacin was remarkably enhanced compared with that in the absence of it. Under the optimum reaction conditions the chemiluminescence increment produced was proportional to the concentration of levofloxacin in the range of 1.0–700.0 ng ml–1 (R2═0.9992), with a detection limit of 0.3 ng ml–1 (3σ). At the flow rate of 2.0 ml min–1, the whole process including sampling and washing could be completed in 0.5 min offering the sampling efficiency of 120 times h–1 accordingly, and the relative standard deviation (RSD) was less than 3.0% (n═5). The recovery for the levofloxacin samples was from 95.9% to 104.5%. It was satisfactory for the application to determine levofloxacin in pharmaceutical preparations, human urine and serum samples.
Ultrasensitive determination for picomolar-level midecamycin in human serum by flow injection chemiluminescence using luminol–BSA system
Hairu Lv,Xijuan Tan,Yun Zhang,Zhenghua Song
Spectroscopy: An International Journal , 2011, DOI: 10.3233/spe-2012-0563
Abstract: An ultrasensitive method for determining picomolar midecamycin (MID) by flow injection (FI) chemiluminescence (CL) was first described based on the inhibitory effect of MID on luminol–BSA reaction. It was found that the CL intensity decrements were linear with the logarithm of MID concentrations in the range of 1.0–5000 pmol · l–1 with a detection limit as low as 0.3 pmol · l–1 (3σ). The relative standard deviation of seven repetitive measurements for 10 pmol · l–1 MID was 3.0%. At a flow rate of 2.0 ml · min–1, the whole analysis procedure including sampling and washing could be finished in 30 s, offering the sample efficiency of 120 h–1. This proposed method was successfully applied to determine MID in human serum samples with the recoveries from 96.0 to 110.0%. The CL mechanism of luminol–BSA–MID reaction was also given.
Rapid assay of picogram level of sudan I in hot chilli sauce by flow injection chemiluminescence
Xiaofei Gao,Houyong Liu,Zhenghua Song,Xili He,Faxin Dong
Spectroscopy: An International Journal , 2007, DOI: 10.1155/2007/704349
Abstract: A novel chemiluminescence method for the assay of sudan I was designed using flow injection with chemiluminescence detection. The proposed method was based on the increment effect of sudan I on the chemiluminescence intensity in the luminol–KIO4 system. The increment of chemiluminescence intensity was correlated with the sudan I concentration in the range from 0.1 to 10 pg ml?1, and the determination could be performed in 0.5 min in flow rate of 2 ml min?1, including sampling and washing, giving a throughput of 120 h?1 with a relative standard deviation of less than 5.0%. The method had been successfully applied to the assay of sudan I in Pixian douban, Golden mark guilin chilli sauce and Golden mark satay sauce, and the recovery was 90.0–103.8%.
SSVEP Extraction Based on the Similarity of Background EEG
Zhenghua Wu
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0093884
Abstract: Steady-state Visual Evoked Potential (SSVEP) outperforms the other types of ERPs for Brain-computer Interface (BCI), and thus it is widely employed. In order to apply SSVEP-based BCI to real life situations, it is important to improve the accuracy and transfer rate of the system. Aimed at this target, many SSVEP extraction methods have been proposed. All these methods are based directly on the properties of SSVEP, such as power and phase. In this study, we first filtered out the target frequencies from the original EEG to get a new signal and then computed the similarity between the original EEG and the new signal. Based on this similarity, SSVEP in the original EEG can be identified. This method is referred to as SOB (Similarity of Background). The SOB method is used to detect SSVEP in 1s-length and 3s-length EEG segments respectively. The accuracy of detection is compared with its peers computed by the widely-used Power Spectrum (PS) method and the Canonical Coefficient (CC) method. The comparison results illustrate that the SOB method can lead to a higher accuracy than the PS method and CC method when detecting a short period SSVEP signal.
Multiplex detection of KRAS and BRAF mutations using cationic conjugated polymers
BaoLing Xing,JinZhao Song,SuMei Ge,ZhengHua Tang,MengLu Liu,Qiong Yang,FengTing Lü,LiBing Liu,Shu Wang
Chinese Science Bulletin , 2013, DOI: 10.1007/s11434-012-5553-9
Abstract: The mutation detections of KRAS and BRAF genes are of significant importance to predict the responses to anti-cancer therapy and develop new drugs. In this paper, we developed a multi-step fluorescence resonance energy transfer (FRET) assay for multiplex detection of KRAS and BRAF mutations using cationic conjugated polymers (CCP). The newly established detection system could detect as low as 2% mutant DNAs in DNA admixtures. By triggering the emission intensity change of CCP and the dyes labeled in the DNA, four possible statuses (three mutations and one wildtype) can be differentiated in one extension reaction. The detection efficiency of this new method in clinical molecular diagnosis was validated by determining KRAS and BRAF mutations of 51 formalin-fixed paraffin-embedded (FFPE) ovary tissue samples. Furthermore, the result of the CCP-based multi-step FRET assay can be directly visualized under UV light so that no expensive instruments and technical expertise are needed. Thus, the assay provides a sensitive, reliable, cost-effective and simple method for the detection of disease-related gene mutations.
Introduction of pokeweed antiviral protein cDNA intoBrassica napus and acquisition of transgenic plants resistant to viruses
Haiyan Zhang,Yingchuan Tian,Yihua Zhou,Benyuan Dang,Haiyan Lan,Guiying Song,Lanlan Wang,Guizhen Liu,Lihua Zhang,Zhenghua Chen
Chinese Science Bulletin , 1999, DOI: 10.1007/BF02909706
Abstract: Using cotyledonary petioles as explants, the PAP cDNA controlled by wound-inducible promoter has been introduced intoBrassica napus by coculture withAgrobacterium tumefaciens and laser microbeam puncture respectively. Regenerated plants resistant to gentamycin have been selected out. PCR amplification and Southern blotting analysis indicated that PAP cDNA together with wound-inducible promoter had been integrated intoBrassica genome with transformation frequencies of 2.0% and 1.7% for two transformation methods respectively. The test of virus challenge showed that these transgenicBrassica plants were resistant in different degrees to mechanically inoculated TuMV.
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