Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “quantitative analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources
PubMed2001

[Using genetic algorithm for quantitative analysis of overlapped spectra in FTIR].

Technique for the quantitative analysis of FTIR spectra, which are serious overlapped in the spectral bands, is studied by genetic algorithm. The multicomponent in the mixture, which contains ten air toxic organic components, such as benzene, phenixin, chlorobenzene, nitrobenzene, phenol, toluene, methanol, o-cresol, m-cresol and p-cresol, is simultaneously determined. The effect of the probability of crossover and the establishment of objective function are discussed. The method of adaptive mutation is used. The results indicate that genetic algorithm has excellent non-linear ability of solution. Mean relative error of each results is really small, generally not bigger than 1%, when the conditions are properly controlled.

Algorithms↗
PubMed1979

Quantitative analysis of two-dimensional electrophoretograms.

A method for quantitative analysis of complex film density distributions in autoradiograms is described. The method is intended particularly for measuring the distribution of radioactivity among the proteins resolved by two-dimensional gel electrophoresis but should, of course, be suited to analyzing other two dimensional separations. The film density distribution is first digitized by a high speed rotating drum scanner to generate the image data array that is stored on a magnetic disk. Subsequent analysis involves: 1) data averaging, 2) detection of contours and of their locations, 3) splitting of overlapping spots, 4) conversion of film density to radioactive intensity by means of calibration films, and 5) differentiation and integration to measure the total radioactivity contained in the protein which generates a spot in the autoradiogram. The product of the analysis is a numbered contour map and a table listing coordinates and radioactivity content of each resolved spot. Coordinate transformations for comparison and matching of autoradiograms are also described. A set of utility programs print and graph the data at intermediate stages of the analysis in order to facilitate the checking of procedures and programs.

Autoradiography↗
PubMed1993

Evaluation of storage phosphor imaging for quantitative analysis of 2-D gels using the Quest II system.

The advent of storage phosphor technology has been of considerable benefit to the imaging of gel-separated radiolabeled proteins due to the rapid and quantitative nature of the data acquisition process. Previously, times over one month were required to obtain fluorographs of the same gel to yield data of sufficient dynamic range for quantitative analysis of high-resolution two-dimensional (2-D) gels. As we are in the process of building a human 2-D gel protein database, and therefore have a high throughput of 2-D gels both to image and quantitate using the Quest II software, we undertook an evaluation of a storage phosphor imager, including an evaluation of signal fade. The results of this evaluation demonstrate the feasibility of using such a system, and we describe the procedures that allow us to use this technique for quantitative analysis of many complex 2-D gel patterns. These procedures include a useful batch printing program that allows printing of many images in a non-interactive mode. Examples will be presented of how autoradiography, using storage phosphor plates and the Quest II system, have enabled us to begin building a human 2-D gel protein database including posttranslational modification information, without the previous time constraints associated with such a project.

Autoradiography↗
PubMed2005

Three-dimensional visualization and quantitative analysis of cervical cell nuclei with confocal laser scanning microscopy.

OBJECTIVE: To develop a method for the acquisition and processing of 3-dimensional images based on confocal laser scanning microscopy for the purpose of 3-dimensional visualization and quantitative analysis of cell nuclei. STUDY DESIGN: A contour-based surface rendering method was used, and volume rendering was implemented according to the basic volume rendering pipeline. To extract quantitative features, a 3-dimensional labeling method based on slice information was used. After applying the labeling algorithm, the measurements for 3-dimensional quantitative analysis of nuclei were extracted: nuclear volume, surface area and spherical shape factor. We compared the 3-dimensional features of normal and abnormal cervical cell nuclei. RESULTS: Comparison of the size of 3-dimensional cervical cell nuclei between normal and abnormal revealed a statistically significant difference. The proposed method could overcome the limitation inherent in 2-dimensional analysis and could become a way of improving the accuracy and reproducibility of quantification of cell nuclei. CONCLUSION: Three-dimensional visualization and quantification of cell nuclei provide valuable medical information that can lead to a more objective diagnosis.

Algorithms↗
PubMed1991

[Clinical application of image processing system and quantitative analysis of left ventriculogram and coronary arteriogram].

Currently cine left ventriculography and coronary arteriography are still one of the most important methods in the diagnosis of coronary heart disease and other coronary arterial diseases. An image processing system, called "IA-87 Medical Image Processing System", for quantitative analysis of cine-coronary and left ventricular angiograms has been developed using IBM-PC/AT computer. The major functions of this system are: (1) left ventricular volume determination, i.e. left ventricular contour can be drawn automatically or semi-automatically, the systolic and diastolic volume of the left ventricle are calculated by Simpson's, length-area and chord-length methods. (2) left ventricular segmental wall motion analysis, using rectilinear and polar method, the segmental ejection fraction and normalized segmental contraction are determined. (3) dynamic display of the cardiac cycle. (4) coronary arterial lesion, such as stenosis, can be quantitatively analysed. In a series of cases free from cardiac disease the normal coronary artery (40 cases) and left ventricle (30 cases) were quantitatively analysed using "IA-87 Medical Image Processing System", and the normal value of coronary artery diameter and left ventricular function among Chinese obtained. At the same time, in a series of 45 cases with coronary heart disease (including anterior, posterior wall infarction, and left ventricular aneurysm in 15 respectively), quantitative analysis of the left ventricle was made. The results showed that the system is of significant value for quantitative diagnosis of ischemic heart disease as well as evaluation of therapeutic effect and prediction of prognosis.

Cineangiography↗
PubMed1989

[Definitive diagnosis of early malignant melanoma lesions by the quantitative analysis of 5-S-cysteinyldopa in the tissue and touch fluorescence method].

Methods for making diagnoses of early lesions of malignant melanomas using a touch-fluorescence method from the cut surface of the lesions and quantitative analysis of 5-S-CD in the tissues were developed. 1) The touch-fluorescence method and analyses of 5-S-CD values in the tissues were extremely useful in making definitive diagnoses of early lesions of nodular melanoma (NM). 2) Only quantitative analyses of 5-S-CD values in the tissues were useful in making definitive diagnoses of early lesions of superficial spreading melanoma (SSM). 3) It is impossible to definitively diagnose lentigo maligna using either way mentioned above. From these results, it appears that quantitative analysis of 5-S-CD values in the tissue was the most useful method for making definitive diagnoses in case of early lesions of NM and SSM.

Adolescent↗
PubMed1992

New bone formation in the in vivo implantation of bioceramics. A quantitative analysis.

Two kinds of synthetic biomaterial, porous tricalcium phosphate (PTCP) and magnetic porous tricalcium phosphate (MPTCP) ceramic granules were implanted in rat femur. In the period of 4 months, the assessment of serial histological sections, scanning electron microphotographs and quantitative analysis of bone formation in the sections showed that both ceramics are biocompatible and degradable in vivo. More new bone formation occurred in the MPTCP group. Endochondral ossification was seen in both groups. The quantitative analysis in this study is reliable, and may be suitable to the similar experimental models.

Animals↗
PubMed1997

Qualitative and quantitative analysis of locus coeruleus neurons in Parkinson's disease.

The analysis of qualitative changes in the locus coeruleus (LC) was performed on brains from 21 cases of Parkinson's disease. Eleven cases were selected for quantitative analysis of the loss of LC noradrenergic pigmented neurons. The qualitative studies revealed uneven dissemination of the noradrenergic cells loss of overall structure of the LC. Few preserved neurons showed degenerative changes. Extracellular neuromelanine granules, traces of dying neurons, were also observed. A weak astro- and microglia proliferation corresponded with neuronal loss. Lewy bodies were found in the LC in all cases. The quantitative analysis revealed that the average loss of adrenergic neurons in the LC accounts for about 70% in relation to the control group. The degenerative changes were observed in the whole LC, but they were most intensive in its caudal and next in the middle segment. The results suggest also that the degenerative process began in the middle segment and then it spread towards caudal segment of the LC as the stages of disease advanced.

Aged↗
PubMed1988

Three-dimensional ultrastructure and quantitative analysis of the human Sertoli cell nucleolus.

The nucleolus of the human Sertoli cell displays a spontaneous segregation of its components and has only one or 2 large fibrillar centers. The 3-dimensional reconstruction and quantitative analysis of its components was undertaken using a Quantimet 900 image analysis system in order to define the spatial relationships between the dense fibrillar component and the fibrillar center and especially to investigate whether threads of dense fibrillar component exist independently, without being linked to a fibrillar center. Our 3D reconstructions demonstrated that the dense fibrillar threads or sheets were never independent of fibrillar centers. These structures belonged to a continuous network that joined the layer of dense fibrils surrounding the fibrillar center. When the nucleolus contained 2 different-sized fibrillar centers, quantitative analysis showed that there was a proportional relationship between the volume of the dense fibrillar component and the volume of the fibrillar center. These data, compared with those previously obtained by means of autoradiographic techniques, suggest that the rDNA-containing chromatin passes through the fibrillar center and unwinds from there into the dense fibrillar component.

Cell Nucleolus↗
PubMed2006

[Quantitative analysis of steroidal saponins in Chinese material medica Rhizoma Paridis by HPLC-ELSD].

OBJECTIVE: The several species of the genus Paris called as Rhizoma Paridis were famous traditional Chinese medica. To develop the quantitative analysis method of the steroidal saponins in some species of the genus Paris and commercially available Rhizoma Paridis samples by HPLC-ELSD. METHOD: The contents of 11 steroidal saponins in Rhizoma Paridis samples were dectected with a Kromasil C18(4.6 mm x 150 mm, 5 microm) column which was deluted with acetonitrile-water (30:70-60:40) at a flow rate of 1 mL x min(-1) by HPLC-ELSD. RESULT: All the authentic samples could be separated and calibration curves of 11 saponins were prepared. 11 steroidal saponins in 16 Rhizoma Paridis samples were detected in 30 min. The recovery for the assay of saponins was between 95% and 97%. The precision and stability of samples (RSD) were below 3%. CONCLUSION: The method was shown to be accurate and convenient, and suitable for the quantitative analysis of these 11 steroidal saponins in the commercially available Rhizoma Paridis samples.

Chromatography, High Pressure Liquid↗
PubMed1998

Quantitative analysis of valence electron energy-loss spectra of aluminium nitride.

The optical properties and electronic structure of aluminium nitride are determined using valence electron energy-loss spectroscopy in a dedicated scanning transmission electron microscope. Quantitative analysis of the experimental valence electron energy-loss spectra to determine the electronic structure encompasses single scattering deconvolution of the valence electron energy-loss spectra to calculate the energy-loss function, Kramers-Kronig analysis of the energy-loss function to reveal the complex dielectric function, transformation of the dielectric function into the optical interband transition strength via optical property relations and finally critical-point analysis of the interband transition strength. The influence of both experimental and analytical parameters on the final result was studied systematically to define and improve the understanding of the methods. To check the reliability of this technique the interband transition strength determined was compared with results of vacuum ultraviolet spectroscopy. Good agreement was found if sample preparation was taken into account. The preparation of the specimen for the transmission electron microscopy has an effect on the electronic structure. Quantitative analysis of valence electron energy-loss spectroscopy, using the methods presented, is an important and capable method to determine the electronic structure of materials and it has the benefit of high spatial resolution.

Journal Article↗
PubMed1993

Quantitative analysis of low molecular weight compounds of biological interest by matrix-assisted laser desorption ionization.

Internal standards were used to demonstrate that matrix-assisted laser desorption/ionization (MALDI) mass spectrometry can be applied to the quantitative analysis of low molecular weight polar compounds. Three examples were tested: a standard curve for 3,4-dihydroxyphenylalanine (DOPA) was prepared using a stable isotope analogue (i.e., [13C6]DOPA) as an internal standard; [2H16]-acetylcholine was employed as an internal standard for the quantification of acetylcholine; and in the final example, the peptide Ac-Ser-Ile-Arg-His-Tyr-NH2 was used as an internal standard for the quantification of the peptide H-Ser-Ala-Leu-Arg-His-Tyr-NH2. In each instance, straight line fits (r2 > 0.95) demonstrate that MALDI is a viable approach for the quantitative analysis of low molecular weight analytes.

Acetylcholine↗
PubMed2000

Low-dose dobutamine radionuclide ventriculography for prediction of myocardial viability: quantitative analysis of regional left ventricular function.

BACKGROUND: It is important to distinguish viable myocardium from necrotic tissue in order to decide upon therapy in patients with ischemic heart disease. HYPOTHESIS: We verified the hypothesis that quantitative analysis of regional left ventricular function using low-dose dobutamine radionuclide ventriculography (RNV) can sensitively predict myocardial viability and compared its usefulness with thallium-201 (201Tl) single-photon emission computed tomography (201Tl-SPECT). METHODS: Radionuclide ventriculography at rest and during low-dose dobutamine infusion (5 micrograms/kg/min), 201Tl-SPECT, and coronary angiography were performed in 51 subjects with severe ischemia-related stenosis of coronary arteries and 3 subjects without coronary artery disease. 201Tl uptake was assessed as normal (control), low perfusion (LP), or defect. We compared the response of regional function to dobutamine with the regional 201Tl uptake. The accuracy of both methods for identifying viable myocardium was investigated in 17 patients who underwent successful coronary revascularization, with a resulting improvement in wall motion. RESULTS: The increase in regional ejection fraction (delta r-EF) in response to dobutamine was significantly greater in the control (12 +/- 6%) and LP (16 +/- 11%) regions than in the defect (5 +/- 10%) regions. The increase in one-third regional ejection fraction (delta r-1/3EF) was also significantly higher in the control (14 +/- 7%) and LP (10 +/- 8%) regions than in the defect regions (5 +/- 6%). We defined myocardial viability as a delta r-EF > 5% or a delta r-1/3EF > 2%. The sensitivity and specificity of the delta r-EF for identification of myocardial viability were 91.4 and 55.5%, respectively. The sensitivity and specificity of the delta r-1/3EF were 91.4 and 66.6%, respectively; the corresponding values for 201Tl SPECT were 74.2 and 77.8%. CONCLUSION: Low-dose dobutamine RNV with quantitative analysis of regional left ventricular function was more sensitive for identification of viable myocardium than 201Tl-SPECT.

Aged↗
PubMed1992

Quantitative analysis of reflex responses in the averaged surface electromyogram.

The relationship between the averaged surface electromyogram (EMG) and the activity of motoneurones in reflex studies is analysed mathematically. This analysis reveals that, subject to certain conditions being met, the integral of the average of the unrectified EMG is linearly related to the activity of motor units in the muscle. This was tested with experimental data. The activity of 2 motor units, and the surface EMG, were recorded directly in a reflex paradigm. A close match was found between the integral of the average of the unrectified EMG and the summed peristimulus time histograms (PSTHs) of the units' activity. This analysis gives more quantitative measurements of the timing of motoneuronal activity in reflexes than the conventional analysis of the EMG. It also offers the potential for making quantitative measurements of changes in motor unit activity evoked by different stimuli. This analysis avoids the pitfall of the artefactual peaks that can occur in the average of the rectified EMG as a consequence of the full-wave rectification. It is concluded that the integral of the unrectified average offers a valuable adjunct to the conventional analysis in many reflex studies. The analysis can also be applied to quantitative studies of neurograms.

Action Potentials↗
PubMed2000

Quantitative analysis of acid-base balance in show jumpers before and after exercise.

The acid-base status of venous blood was studied in 17 show jumpers before and after exercise using both a traditional and a quantitative approach. Partial pressure of carbon dioxide (PCO(2)), pH, haemoglobin, and plasma concentrations of sodium (Na(+)), chloride (Cl(-)), potasium (K(+)), ionized calcium (Ca(2+)), total proteins, albumin, lactate and phosphorus were measured in jugular venous blood samples obtained before and immediately after finishing a show jumping competition. Bicarbonate, anion gap and globulin concentration were calculated from the measured parameters. 'Quantitative analysis' of acid-base balance was performed utilising values for three independent variables: PCO(2), strong ion difference [SID = (Na(+)+ K(+)+ Ca(2+)) - (Cl(-)+ Lact)] and total concentration of weak acids [A(T)= Alb (1 paragraph sign23 pH - 6 paragraph sign31) + Pi (0 paragraph sign309 pH - 0 paragraph sign469) 10/30 paragraph sign97]; plasma concentrations of hydrogen ion ([H(+)]) were also calculated from these variables using Stewart's equation. No significant changes in blood pH were detected after the show jumping competition. Exercise resulted in a significant increase in lactate, Na(+), K(+), haemoglobin, total proteins, albumin, globulin and anion gap, and a decrease in bicarbonate, Cl(-)and Ca(2+). PCO(2)decreased after exercise while SID and A(T)increased. A significant correlation between measured and calculated [H(+)] was found both before and after exercise. However, individual [H(+)] values were not accurately predicted from Stewart's equation. In conclusion, even though pH did not change, significant modifications in the acid-base balance of horses have been found after a show jumping competition. In addition, quantitative analysis has been shown to provide an adequate interpretation of acid-base status in show jumpers before and after exercise.

Acid-Base Equilibrium↗
PubMed2005

SAGE and the quantitative analysis of gene expression in parasites.

The nature of an organism is defined by the genes that it expresses. Genome- and expressed-sequence-tag (EST) sequencing projects are underway for many of the major parasites of humans and animals. These provide essential datasets that delineate the genes present in an organism and, in the case of ESTs, some quantitative information on gene expression. The temporal and quantitative analysis of gene expression is essential to fully exploit these datasets and define the biology of the parasite at the molecular level. Here, we discuss the application of serial analysis of gene expression (SAGE) for this purpose. SAGE is a technique that allows the rapid, quantitative analysis of thousands of transcripts. It complements microarray analysis with the advantage that it is affordable for standard laboratories. It provides a platform to define complete metabolic pathways and has been applied to study responses to drug treatment and the molecular events that are associated with arrested larval development.

Animals↗
PubMed2006

Rapid separation and quantitative analysis of peptides using a new nanoelectrospray- differential mobility spectrometer-mass spectrometer system.

Differential mobility spectrometry (DMS) (see Buryakov, I. A.; Krylov, E. V.; Nazarov, E. G.; Rasulev, U. Kh. Int. J. Mass Spectrom. Ion Processes 1993, 128, 143-148), also commonly referred to as high-field asymmetric waveform ion mobility spectrometry (FAIMS) (see Purves, R. W.; Guevremont, R.; Day, S.; Pipich, C. W.; Matyjaszcyk, M. S. Rev. Sci. Instrum. 1998, 69, 4094-4105), is a rapidly advancing technology for gas-phase ion separation. The interfacing of DMS with mass spectrometry (MS) offers potential advantages over the use of mass spectrometry alone. Such advantages include improvements to mass spectral signal-to-noise, orthogonal/complementary ion separation to mass spectrometry, enhanced ion and complexation structural analysis, and the potential for rapid analyte quantitation. In this report, we investigate the use of our nanoESI-DMS-MS system to demonstrate differential mobility separation of peptides. The formation of higher order peptide aggregate ions (ion complexes) via electrospray ionization and the negative impact this has on DMS peptide separation are examined. The successful use of differential mobility drift gas modifiers (dopants) to reduce aggregate ion size and improve DMS peptide ion separation is presented. Following optimization of DMS peptide separation conditions, we examined next the feasibility of a new analytical platform which uses direct sample infusion with nanoESI-DMS-MS for ultrarapid analyte quantitation. Quantitation of a selected peptide from a semicomplex peptide mixture is presented. Initial feasibility results with this new approach demonstrate good accuracy and reproducibility, as well as an absolute mass sensitivity of 6.8 amol and a minimum dynamic range of 2500 for the peptide of interest. This report offers a first look at utilizing nanoESI-DMS-MS to create an ultrarapid (under 5 s) quantitative analysis platform and its potential in the high-throughput arena. Each ion separation technique, DMS and MS, offers orthogonal ion separation to one another, enhancing the overall specificity for this quantitative approach.

Mass Spectrometry↗
PubMed1992

[Use of automated quantitative analysis of electroencephalograms in the diagnosis of dementia].

The submitted paper demonstrates the differential diagnostic value of automatic quantitative analysis of electroencephalograms in the diagnosis of dementia and functional mental disorders in old age. By quantitative autoregression analysis of electric activity of the brain in a group of 53 hospitalized patients (incl. 33 cases of dementia) the conclusions of visual analysis were confirmed as well as the comparability of results obtained by other methods of automatic analysis. Signs characterizing the electroencephalogram in dementia (reduced ratio of alpha activity and increase of slow activity, low value of A/T index, shift of the peak frequency towards slow activity) make differential diagnosis of dementia in organic diseases from pseudodementia possible. Analysis of the results indicates that automatic analysis can be very successful in the detection of Alzheimer's disease.

Aged↗