Search results for "Samples"
showing 10 items of 133 documents
Fit-for-purpose chromatographic method for the determination of amikacin in human plasma for the dosage control of patients
2015
In this paper, a simple, rapid and sensitive method based on liquid chromatography with fluorimetric detection (HPLC-FLD) for the determination of amikacin (AMK) in human plasma is developed. Determination is performed by pre-column derivatization of AMK with ortho-phtalaldehyde (OPA) in presence of N-acetyl-L-cysteine (NAC) at pH 9.5 for 5 min at 80 °C. In our knowledge, this is the first time that NAC has been used in AMK derivatization. Derivatization conditions (pH, AMK/OPA/NAC molar ratios, temperature and reaction time) are optimized to obtain a single and stable, at room temperature, derivative. Separation of the derivative is achieved on a reversed phase LC column (Kromasil C18, 5 μ…
Seeking the Holy Grail: robust chronologies from archaeology and radiocarbon dating combined
2018
The strengths of formal Bayesian chronological modelling are restated, combining as it does knowledge of the archaeology with the radiocarbon dating of carefully chosen samples of known taphonomy in association with diagnostic material culture. The risks of dating bone samples are reviewed, along with a brief history of the development of approaches to the radiocarbon dating of bone. In reply to Strien (2017), selected topics concerned with the emergence and aftermath of the LBK are discussed, as well as the early Vinča, Ražište and Hinkelstein sequences. The need for rigour in an approach which combines archaeology and radiocarbon dating is underlined.
On-line in-tube solid phase microextraction coupled to capillary liquid chromatography-diode array detection for the analysis of caffeine and its met…
2019
Abstract In-tube solid phase microextraction (IT-SPME) coupled on-line to capillary liquid chromatography with diode array detection provides a simple and fast analytical methodology for the simultaneous quantitation of caffeine and its three primary metabolites (theobromine, paraxanthine and theophylline) in micro samples of serum, saliva and urine matrices. The sample amount required for one analysis was only 2.5 μL of saliva, 6.25 μL of serum or 40 μL of urine, a requirement for its implementation in a hospital laboratory for preterm newborns, where sample availability is a major problem. In standard conditions, 25 μL of diluted saliva or serum (or 100 μL of urine) were processed by IT-S…
Estimation of Pyruvic acid in serum and saliva among healthy and potentially malignant disorder subjects – a stepping stone for cancer screening?
2014
Background: According to Warburg’s effect, the rate of glycolysis increases in cancerous cells. This will increase overall levels of pyruvic acid. The present on-going study was conducted to estimate the levels of pyruvic acid in saliva and serum in normal, oral PMD subjects. Material and Methods: A total of 50 subjects in healthy, PMD of the oral cavity individuals were selected based on clinical and histological criteria. Collected saliva and serum samples were subjected to pyruvic acid level estimation using biochemical analysis. Results: Of the 50 participants 25 (13: Males; 12: Females) & 25 (16: Males; 9: Females) were PMD group. Independent samples t test showed statistically signifi…
A new method for fluoride determination by using fluorophores and dyes anchored onto MCM-41
2002
A new colourimetric and fluorimetric method for fluoride determination in aqueous samples based on the specific reaction between fluoride and silica has been developed and applied on real samples. Descalzo Lopez, Ana Belen, adeslo@alumni.uv.es ; El Haskouri, Jamal, Jamal.Haskouri@uv.es ; Beltran Porter, Daniel, Daniel.Beltran@uv.es ; Amoros del Toro, Pedro Jose, Pedro.Amoros@uv.es
From the Beehives: Identification and Comparison of Physicochemical Properties of Algerian Honey
2021
In this study, the authors aimed at characterizing 11 Algerian kinds of honey taken from various geographical locations (beehives located at Djelfa (Medjbara and Dzaira), Laghouat, Aflou, Medea, Tiaret, Sidi bel-Abbes, Tiaret, Ain-Safra, Mostaganem, El Bayadh, and Ghardïa). The authors investigated the physicochemical parameters of these honey samples, including density, water content, electrical conductivity, ash content, pH, hydroxymethylfurfural (HMF) content, free acidity, and color. The physicochemical parameters obtained were found to be within acceptable ranges according to the international standards (Codex Alimentarius) for 9 out of 11 analyzed samples: density 1.38–1.50 g/cm3 (the…
Biological tolerance of different materials in bulk and nanoparticulate form in a rat model: sarcoma development by nanoparticles
2006
In order to study the pathobiological impact of the nanometre-scale of materials, we evaluated the effects of five different materials as nanoparticulate biomaterials in comparison with bulk samples in contact with living tissues. Five groups out of 10 rats were implanted bilaterally for up to 12 months with materials of the same type, namely TiO 2 , SiO 2 , Ni, Co and polyvinyl chloride (PVC), subcutaneously with bulk material on one side of the vertebral column and intramuscularly with nanoparticulate material on the contralateral side. At the end of each implantation time, the site was macroscopically examined, followed by histological processing according to standard techniques. Malign…
Measuring expectation for an affordance gap on a smartphone user interface and its usage among older adults
2020
The smartphone has become a ubiquitous mobile communication tool that plays a crucial role in the daily lives for Malaysian older adults. However, it is not easy for older adults to learn new interaction modes and adopt the smartphone user interface. In this paper, we aim to examine the affordances of a smartphone user interface and its usage by older adults through the lens of Norman’s execution/evaluation action cycle (EEAC) framework. A mobile-user interaction study was administered with four tasks. A paired sample t-test was conducted to analyze the affordance gap between different levels of expectation. The results revealed that three tasks (making phone calls, adding contacts, and usi…
Electronic paramagnetic resonance power saturation of wooden samples
2009
The deterioration of wood used for artifacts of artistic interest involves the production of different free radicals from the macromolecules of the wooden matrix (cellulose, lignin, and hemicellulose). Among the techniques able to provide information about these free radicals, the contribution of electronic paramagnetic resonance (EPR) can be very valuable. In this paper, the study of EPR signals (with g 2) of both modern and ancient wooden taxa was undertaken in order to analyze some features of the free radicals in natural wood. In particular, we have studied the microwave power saturation behaviors of seasoned wooden samples from ten species, and we have found remarkable differences betw…
Determination of benzomercaptans in environmental complex samples by combining zeolitic imidazolate framework-8-based solid-phase extraction and high…
2020
[EN] In this work, the synthesis of zeolitic imidazolate framework-8 (ZIF-8) crystals and their subsequent application as effective sorbents for extraction and preconcentration of several benzomercaptans from environmental complex samples is described. These materials were prepared by solvothermal approach varying the concentration of n-butylamine modulator to modify the surface of the metal-organic framework. The resulting materials were characterized by scanning and transmission electron microscopy, powder X-ray diffraction and Fourier transform infrared spectroscopy. The ZIF-8 material that gave the best features was selected as extractive phase and the influence of various parameters (s…