Search results for "quantitative analysis"
showing 10 items of 304 documents
F-2-isoprostanes: review of analytical methods
2006
International audience; F2-isoprostanes (F2-isoPs) represent a new family of biomarkers for oxidative stress generated by free radical attack of membrane-bounded arachidonic acid. Esterified F2-isoPs can be found in tissue or plasma lipids whereas the free form F2-isoPs, hydrolyzed by phospholipase, is mainly present in body fluids. The extent of systematic damage due to oxidative stress within the body can be assessed by the determination of plasma or urine F2-isoPs. The determination of F2-isoPs in clinical practice is not often used due to the complexity to extract the compounds from their biologic matrixes before the analysis step. In most of published protocols, extraction procedure is…
Investments in Latvia
2021
The effective attraction of investments to the national economy is a key factor, which provides favourable conditions to perform structural changes in the national economy, regional development as well as promotes technical progress. Therefore, investments in the public and the private sectors conduce development of the national economy and provide conditions to increase the overall competitiveness of a country. The purpose of research is to evaluate investment processes in Latvia before and after the global financial crisis, revealing investment-related problems. Also, to calculate the level of the desired investment, which would ensure the Latvia’s average GDP growth of 5% per year, accor…
Quantitative analysis of modified functional muscle–bone unit and back muscle density in patients with lumbar vertebral fracture in Chinese elderly m…
2018
Objectives: Bone mineral density (BMD) is associated with muscle mass and quality, but little research has been done on functional muscle–bone unit and back muscle density in patients with lumbar vertebral fracture. This study used the “modified functional muscle–bone unit” concept and measured back muscle density to investigate muscle–bone interaction difference between the fracture and control group. Methods: This was a case–control study. A total of 52 elderly male patients (mean age 75 years) with lumbar vertebral fracture (cases) and 52 control healthy subjects were enrolled. Cross-sectional area (CSA) and density of paravertebral muscle were measured in quantitative computed tomograph…
Automated determination of clomipramine and its major metabolites in human and rat serum by high-performance liquid chromatography with on-line colum…
1998
A fully automated method including column-switching and isocratic high-performance liquid chromatography (HPLC) was developed for simultaneous determination of the tricyclic antidepressant clomipramine and its metabolites demethylclomipramine, 2-, 8-, and 10-hydroxyclomipramine, 2-, and 8-hydroxydemethylclomipramine and didemethylclomipramine in serum. After serum injection into the HPLC system and on-line sample clean-up on a clean-up column (Hypersil CN; 10 x 4.6 mm) by an eluent consisting of 35% acetonitrile and 65% deionized water, the chromatographic separation was performed on an analytical column (LiChrospher CN; 250 x 4.6 mm I.D.) by an eluent consisting of 38% acetonitrile and 62%…
Quantitative Analysis of Gender Stereotypes and Information Aggregation in a National Election
2013
By analyzing a database of a questionnaire answered by a large majority of candidates and elected in a parliamentary election, we quantitatively verify that (i) female candidates on average present political profiles which are more compassionate and more concerned with social welfare issues than male candidates and (ii) the voting procedure acts as a process of information aggregation. Our results show that information aggregation proceeds with at least two distinct paths. In the first case candidates characterize themselves with a political profile aiming to describe the profile of the majority of voters. This is typically the case of candidates of political parties which are competing for…
Determination of microcystins in biological samples by matrix solid-phase dispersion and liquid chromatography–mass spectrometry
2005
A method for the detection and quantification of the microcystins (MCs)-MC-LR, MC-RR and MC-YR-in biological samples by matrix solid-phase dispersion (MSPD) has been developed. The optimum extraction conditions were 500 mg of liver or kidney, C18 bonded silica as dispersant, and a mixture methanol-water (70:30) as eluent. The MCs were determined by liquid chromatography electrospray mass spectrometry (LC/ES/MS). Recoveries of biological extracts at three different spiked levels (1-10 mg kg(-1)) ranged from 40.5 to 87.0% in liver, and from 52.5 to 74.5 in kidney. R.S.D.s were < 15.6% and < 10.6%, respectively. The detection and quantification limits were 0.05 and 0.5 mg kg(-1), for all MCs. …
Real-Time Quantification of Human Telomerase Reverse Transcriptase mRNA in the Plasma of Patients with Prostate Cancer
2006
The aim of this study was to evaluate the potential diagnostic value of quantitative analysis of human telomerase reverse transcriptase (hTERT) mRNA in plasma for noninvasive diagnosis of prostate cancer (PCa). Expression levels of hTERT were analyzed by real-time quantitative RT-PCR in 68 patients showing elevated prostate-specific antigen (PSA) levels and a control group of 44 healthy volunteers. Sensitivity and specificity were determined and compared to the corresponding PSA values. Median values for hTERT gene expression in the PCa patients (0.72 ng; range 0.01-12.86) were statistically significantly higher (P < 0.001) than in the control group (0.13 ng; 0.02-0.35). Patients with clini…
Quantitative analysis of the EEG effects produced by imipramine, desipramine, promazine, and monodesmethyl promazine in the isolated perfused rat bra…
1974
The effects of imipramine, desipramine, promazine and monodesmethyl promazine on the EEG of the isolated perfused rat brain were studied. The brain preparation was perfused for 30 min with simulated blood, containing of the drugs in a concentration of 10−5 M. Control experiments were performed without a drug added to the simplified blood. The EEG was recorded at various times on a magnetic tape and was evaluated visually and quantitatively (amplitude and interval histography). The EEG effects of imipramine and promazine as well as the effects of these drugs with their monodesmethyl metabolites were compared. The drugs produced clear EEG changes compared with the control EEG. An increase of …
Determination of microcystins in fish by solvent extraction and liquid chromatography
2005
A liquid chromatography electrospray mass spectrometry (LC/ESI/MS) method has been developed to identify and quantify microcystins in fish liver and intestine. Microcystins (MCs) were extracted from 500 mg sample with methanol-water (85:25, v/v) and the extracts concentrated to 250 microl. The parameters were optimized by a full factorial 2(3) design. Neither laborious pre-treatment nor clean up were necessary. MCs were separated using conventional C18 column and an acetonitrile-acidified water (pH 3) gradient. Negative samples (without MCs) were discriminated by liquid chromatography diode array detection (LC/DAD). The limits of detection (LOD) and the limits of quantification (LOQ) result…
Photo-induced chemiluminometric determination of Karbutilate in a continuous-flow Multicommutation assembly
2006
The present paper deals with the chemiluminescent determination of the herbicide Karbutilate on the basis of its previous photodegradation by using a low-pressure Hg lamp as UV source in a continuous-flow multicommutation assembly (a solenoid valves set). The pesticide solution was segmented by a solenoid valve and sequentially alternated with segments of the 0.001 mol l(-1) of NaOH solution, the suitable media for the formation of photo-fragments; then it passes through the photo-reactor and was lead to the flow-cell after being divided in small segments which were sequentially alternated with the oxidizing system; 2 x 10(-5) mol l(-1) of potassium permanganate in 0.2% pyrophosphoric acid.…