Colorimetric detection of citric acid as the biomarker for urolithiasis based on Sodium dodecylsulfate-AgNPs with a portable CD-spectrometer

2021 ◽  
pp. 339178
Author(s):  
Shuqi Zhou ◽  
Liubing Kong ◽  
Xinyi Wang ◽  
Tao Liang ◽  
Hao Wan ◽  
...  
Keyword(s):  
Citric Acid ◽  
Colorimetric Detection ◽  
Sodium Dodecylsulfate

scholarly journals A Highly Sensitive and Selective Probe for the Colorimetric Detection of Mn(II) Based on the Antioxidative Selenium and Nitrogen Co-Doped Carbon Quantum Dots and ABTS•+

2021 ◽  
Vol 9 ◽  
Author(s):  
Qinhai Xu ◽  
Xiaolin Liu ◽  
Yanglin Jiang ◽  
Peng Wang
Keyword(s):  
Quantum Dots ◽  
Citric Acid ◽  
Detection Limit ◽  
Sodium Selenite ◽  
Tap Water ◽  
Colorimetric Detection ◽  
Carbon Quantum Dots ◽  
Promising Tool ◽  
Highly Sensitive ◽  
Co Doped

Herein, selenium and nitrogen co-doped carbon quantum dots (Se/N-CQDs) were hydrothermally synthesized by using citric acid, histidine, and sodium selenite, which had sp3 and sp2 hybridized carbon atoms and showed excitation-dependent fluorescence behavior. Furthermore, due to the redox reaction of ABTS•+ and Se/N-CQDs, Se/N-CQDs had the excellent antioxidant capacity that it was demonstrated by scavenging ABTS•+ with the fading of blue. Based on the synergistic effect of Se/N-CQDs and Mn(II) on ABTS•+, Se/N-CQDs and ABTS•+, as a stable, sensitive, selective, and reproducible colorimetric sensor, was applied to the detection of Mn(II) with a detection limit of 1.69 μM and a linear range of 0 to 142.90 μM. More importantly, the probe was successfully applied to detecting Mn(II) in tap water, illustrating that it could be a promising tool for Mn(II) detection in water environments.

Coadministration of citric acid allows oxytetracycline dose reduction in yellowtail Seriola quinqueradiata infected with Vibrio anguillarum

2020 ◽  
Vol 140 ◽  
pp. 25-29
Author(s):  
K Akiyama ◽  
N Hirazawa ◽  
A Hatanaka
Keyword(s):  
Body Weight ◽  
Citric Acid ◽  
Effective Treatment ◽  
Dose Reduction ◽  
Vibrio Anguillarum ◽  
Enhancing Effect ◽  
Bacterial Diseases ◽  
Seriola Quinqueradiata ◽  
Poor Efficacy

Oxytetracycline (OTC) has been commonly used as an effective antibiotic against various fish bacterial diseases, including vibriosis. In this study, the absorption-enhancing effect of citric acid on oral OTC pharmacokinetics and treatment of artificial Vibrio anguillarum infection was evaluated in juvenile yellowtail Seriola quinqueradiata followed by serum OTC concentration analysis. When 25 mg kg-1 body weight (BW) OTC was administered in combination with 1250 mg kg-1 BW citric acid, the serum OTC concentration reached almost the same concentration as that of the group treated with 50 mg kg-1 BW OTC. This coadministration successfully suppressed mortality due to vibriosis similar to the group treated with 50 mg kg-1 BW OTC. Conversely, poor efficacy was observed when only 25 mg kg-1 BW OTC was administered. These results suggest that coadministration of citric acid can be beneficial in reducing the dose of OTC needed for effective treatment, and thus contributes to the goal of reduced use of this antibiotic in aquaculture.

EFFECT OF SERUM GONADOTROPHIN ON DEHYDROGENASES OF THE CITRIC ACID CYCLE IN THE OVARY OF THE RAT

1963 ◽  
Vol 42 (4) ◽  
pp. 480-484 ◽  
Author(s):  
B. Eckstein ◽  
R. Landsberg
Keyword(s):  
Citric Acid ◽  
Citric Acid Cycle ◽  
Age Groups ◽  
Succinic Dehydrogenase ◽  
Immature Rat ◽  
Acid Cycle ◽  
Immature Rats ◽  
Rat Ovary

ABSTRACT The succinic, malic and isocitric dehydrogenases in the ovary of immature and mature, normal and serum gonadotrophin injected rats were examined. The Qo2 of these enzymes were markedly enhanced in the gonadotrophin injected rats of both age groups, except in the case of succinic dehydrogenase in the ovary of the immature rats, where a slight non-significant decrease was noted. It is concluded that in the mature rat ovary, gonadotrophin administration stimulates the activity of all the examined dehydrogenases of the citric acid cycle, whereas in the immature rat ovary, at least the isocitric- and malic dehydrogenases are thus stimulated.

Investigation of culture conditions by Response Surface Methodology and kinetic modeling for exopolysaccharide production by Klebsiella oxytoca ICCF 419 strain, using lactose as substrate

2020 ◽  
Vol 25 (6) ◽  
pp. 2033-2044
Author(s):  
CATERINA TOMULESCU ◽  
◽  
MIŞU MOSCOVICI ◽  
ROXANA MĂDĂLINA STOICA ◽  
GABRIEL BUJOR ALBU ◽  
...  
Keyword(s):  
Citric Acid ◽  
Klebsiella Oxytoca ◽  
Fermentation Medium ◽  
Culture Conditions ◽  
Biomass Growth ◽  
Initial Value ◽  
Substrate Consumption ◽  
Polysaccharide Production ◽  
Crude Polysaccharide ◽  
Central Composite

The objective of this work was to optimize the bioprocess parameters, using Klebsiella oxytoca ICCF 419 to obtain an exopolysaccharide based on lactose as substrate. A kinetic study was employed and Logistic and Gompertz models were applied to describe the polysaccharide production, in relation with biomass growth and substrate consumption. The RSM methodology based on Central Composite Rotatable Design was used to evaluate and optimize the effect of lactose, corn extract, KH2PO4 and citric acid concentrations as independent variables on the polysaccharide production, biomass growth and substrate consumption as the response functions. The interaction effects and optimal parameters were obtained using Design Expert Software (version 9.0.6.2). The significance of the variables and their interactions was tested by means of ANOVA analysis with a 99% confidence level. The optimum culture conditions were determined and the model prediction was compared with experimental results. At an initial value of 23.45 for the C/N in the fermentation medium, the strain produces 17.41 g/L of crude polysaccharide and 2.53 g/L dry biomass. The EPS production was significantly influenced by lactose, corn extract and KH2PO4, while the citric acid had no influence. The biomass growth was influenced by the corn extract, KH2PO4 and citric acid.

Directed Evolution of P450 Fatty Acid Decarboxylases via High-Throughput Screening Towards Improved Catalytic Activity

2019 ◽  
Author(s):  
Huifang Xu ◽  
Weinan Liang ◽  
Linlin Ning ◽  
Yuanyuan Jiang ◽  
Wenxia Yang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Fatty Acid ◽  
Directed Evolution ◽  
High Throughput ◽  
High Throughput Screening ◽  
Colorimetric Detection ◽  
Screening Method ◽  
Random Mutagenesis ◽  
Direct Production ◽  
Consumption Activity

P450 fatty acid decarboxylases (FADCs) have recently been attracting considerable attention owing to their one-step direct production of industrially important 1-alkenes from biologically abundant feedstock free fatty acids under mild conditions. However, attempts to improve the catalytic activity of FADCs have met with little success. Protein engineering has been limited to selected residues and small mutant libraries due to lack of an effective high-throughput screening (HTS) method. Here, we devise a catalase-deficient <i>Escherichia coli</i> host strain and report an HTS approach based on colorimetric detection of H<sub>2</sub>O<sub>2</sub>-consumption activity of FADCs. Directed evolution enabled by this method has led to effective identification for the first time of improved FADC variants for medium-chain 1-alkene production from both DNA shuffling and random mutagenesis libraries. Advantageously, this screening method can be extended to other enzymes that stoichiometrically utilize H<sub>2</sub>O<sub>2</sub> as co-substrate.

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