2-(2'- Chloro Phenyl)- 5- (2'-Hydroxyl Phenyl)-1,3,4-Oxadiazole as a Florescent Probe for DNA Determination

2011 ◽  
Vol 301-303 ◽  
pp. 361-365
Author(s):  
Mei Ding ◽  
Ying Jie Lei ◽  
Ou Yang Jie
Keyword(s):  
Experimental Data ◽  
Fluorescence Quenching ◽  
Quantitative Determination ◽  
Fluorescent Probe ◽  
Fluorescence Intensity ◽  
Dna Analysis ◽  
Fluorescence Spectrometry ◽  
Experimental Conditions ◽  
Convenient Synthesis

In recent years, fluorescence spectrometry was widely used in quantitative determination of DNA. In this paper, a convenient synthesis of a new fluorescent 2-(2'- Chloro phenyl)- 5- (2'- hydroxyl phenyl)-1,3,4-oxadiazole (HOXD) was realized. Experimental data showed that fluorescence of HOXD could be quenched by DNA and the decreased fluorescence intensity of HOXD resulting from fluorescence quenching is proportional to DNA concentrations suggesting that HOXD could be used as a new fluorescent probe for quantitative determination of DNA. Optimal experimental conditions for DNA analysis were also studied in the paper.

An “on–off” fluorescent probe based on cucurbit[7]uril for highly sensitive determination of ammonia nitrogen in aquaculture water

2021 ◽  
Author(s):  
Zhen Li ◽  
Tan Wang ◽  
Xianbao Xu ◽  
Cong Wang ◽  
Daoliang Li
Keyword(s):  
Fluorescence Quenching ◽  
Inclusion Complex ◽  
Fluorescent Probe ◽  
Ammonia Nitrogen ◽  
Highly Sensitive ◽  
Sensitive Determination ◽  
Aquaculture Water

A novel “on–off” fluorescent probe for the determination of ammonia nitrogen has been synthesized. URO can replace PAL into the cavity of CB[7] to form a stable inclusion complex, eventually forming the fluorescence quenching system of URO@CB[7].

scholarly journals Accuracy improvement in XRF analysis for the quantification of elements ranging from tenths to thousands μg g−1 in human tissues using different matrix reference materials

2020 ◽  
Vol 35 (12) ◽  
pp. 2920-2927
Author(s):  
Jorge Machado ◽  
Patrícia Miguel Carvalho ◽  
Ana Félix ◽  
Delfin Doutel ◽  
José Paulo Santos ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Reference Materials ◽  
Fluorescence Spectrometry ◽  
Human Tissues ◽  
Accuracy Improvement ◽  
External Calibration ◽  
X Ray ◽  
Xrf Analysis ◽  
Calibration Approach

In this work, we aim at achieving the most accurate quantitative determination of elements in human tissues by means of X-ray fluorescence spectrometry using the external calibration approach.

scholarly journals POSSIBILITIES OF SEMEN STAIN IDENTIFICATION AFTER CLOTHING AND BEDDING WASHING IN INVESTIGATING CASES OF SEXUAL ASSAULT

2020 ◽  
Vol 17 (34) ◽  
pp. 93-111
Author(s):  
Saule Amangeldievna MUSSABEKOVA
Keyword(s):  
Sexual Assault ◽  
Dna Analysis ◽  
Specific Antigen ◽  
Genetic Profile ◽  
Fluorescence Signal ◽  
Experimental Conditions ◽  
Physical Evidence ◽  
Crucial Component ◽  
Multiple Conditions

Identifying semen stains on clothing and bedding is a crucial component in investigating cases of sexual assault. In some cases, clothing and bedding have already been washed before they were removed and sent for forensic examination. There is insufficient data on best practices for handling traces of semen on clothes after washing. This work aimed to study the possibility of identifying traces of semen on clothes after washing using widely used techniques. To simulate typical physical evidence, donor semen samples were applied to pieces of clothing made from various fabrics. The clothes were washed under multiple conditions (with the help of nonbiological and biological (enzyme-containing) agents, and across numerous washing machines). After washing, the washing stains were characterized by the presence of fluorescence signal, spermatozoa (Koren – Stokis method), the determination of acid phosphatase, prostate-specific antigen and semenogelin, as well as the results of serological research according to the AB0 system and DNA analysis. Clothing analysis using these methods was shown to be effective in experimental conditions. However, the presence of enzymes as detergent components designed to destroy biogenic stains significantly affect the results of the identification of semen stains. It has been established that the full genetic profile can be obtained from semen stains even after washing three times. Different strategies are needed to detect, select and identify semen stains depending on the circumstances of a case. It is recommended to examine clothing and bedding, even if the specimens were previously washed.

scholarly journals A Quantitative Determination of Minimum Film Thickness in Elastohydrodynamic Circular Contacts

2021 ◽  
Author(s):  
Wassim Habchi ◽  
Philippe Vergne
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Numerical Model ◽  
Film Thickness ◽  
Quantitative Determination ◽  
Excellent Agreement ◽  
Operating Conditions ◽  
Pure Rolling ◽  
Minimum Film Thickness

Abstract The current work presents a quantitative approach for the prediction of minimum film thickness in elastohydrodynamic lubricated (EHL) circular contacts. In contrast to central film thickness, minimum film thickness can be hard to accurately measure, and it is usually poorly estimated by classical analytical film thickness formulae. For this, an advanced finite-element-based numerical model is used to quantify variations of the central-to-minimum film thickness ratio with operating conditions, under isothermal Newtonian pure-rolling conditions. An ensuing analytical expression is then derived and compared to classical film thickness formulae and to more recent similar expressions. The comparisons confirmed the inability of the former to predict the minimum film thickness, and the limitations of the latter, which tend to overestimate the ratio of central-to-minimum film thickness. The proposed approach is validated against numerical results as well as experimental data from the literature, revealing an excellent agreement with both. This framework can be used to predict minimum film thickness in circular elastohydrodynamic contacts from knowledge of central film thickness, which can be either accurately measured or rather well estimated using classical film thickness formulae.

Label-Free Aptamer Fluorescence Determination of Trace Pb2+ Using AuPd Nanoalloy Probe as Catalyst

2013 ◽  
Vol 631-632 ◽  
pp. 18-21 ◽  
Author(s):  
Zhi Liang Jiang ◽  
Mei Ling Tang ◽  
Qing Ye Liu ◽  
Ai Hui Liang
Keyword(s):  
Detection Limit ◽  
Fluorescence Quenching ◽  
Fluorescence Intensity ◽  
Water Samples ◽  
Catalytic Effect ◽  
Rhodamine 6G ◽  
Label Free ◽  
Double Stranded Dna ◽  
Fluorescence Determination

In the condition of 1.24 mmol/L EDTANa2, 16.7 mmol/L NaCl and 0.17 mmol/L Tris, the substrate chain of double-stranded DNA (dsDNA) could be cracked by Pb2+ to release single-stranded DNA (ssDNA) that adsorb onto AuPd nanoparticle (AuPdNP) and form stable AuPdNP-ssDNA, but the dsDNA can not protect AuPdNP that were aggregated to big AuPdNP aggregations (AuPdNPA) under the action of NaCl. The AuPdNP-ssDNA and AuPdNPA could be separated by centrifugation. With the concentration of Pb2+ increased, the released ssDNA increased, the AuPdNP-ssDNA in centrifugation solution increased and the catalytic effect enhanced on the fluorescence quenching reaction of Rhodamine 6G (Rh6G) and NaH2PO2, which led the fluorescence intensity at 552nm to decrease. The decreased fluorescence intensity (ΔF552nm) was linear to the concentration of Pb2+ in the range of 0.33-8.00 nmol/L, a detection limit of 0.21 nmol/L. The proposed method was applied to detect Pb2+ in water samples, with satisfactory results.

Examination of the potential of copper during its dissolution in sodium hydroxide

1981 ◽  
Vol 46 (12) ◽  
pp. 3057-3062 ◽  
Author(s):  
Petr Sušinka ◽  
Milica Miadoková
Keyword(s):  
Quantitative Determination ◽  
Sodium Hydroxide ◽  
Oxygen Electrode ◽  
Quantitative Relation ◽  
Experimental Conditions ◽  
Kinetic Measurements ◽  
Crystallographic Planes ◽  
The Given ◽  
Spontaneous Reaction

Parallel to kinetic measurements, the potential of copper was monitored on the (100), (110), and (111) crystallographic planes during its spontaneous reaction in sodium hydroxide in oxygen atmosphere. A quantitative relation was obtained for the potential in dependence on the experimental conditions, indicating that unless a passivating layer of copper(II) oxide is formed on the surface, the metal does not act as an oxygen electrode. The potential change in the given medium was found to depend only on the amount of copper(I) oxide formed, obeying the relation E = (RT/nF) ln (mCu2O) + K; use was made of this relation for a quantitative determination of the growth of the copper(I) oxide layer.

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