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Quantitative Evaluation (quantitative + evaluation)

Distribution by Scientific Domains

Medical Sciences	40%
Chemistry	17%
Life Sciences	16%
Engineering	8%
Polymers and Materials Science	6%
Physics and Astronomy	3%
Earth and Environmental Science	3%
Humanities and Social Sciences	2%

Distribution within Medical Sciences

Radiology & Imaging	15%
Dermatology	5%
20 Other Subdomains	75%

Selected Abstracts

Quantitative Evaluation of Left Ventricle Performance from Two Dimensional Echo Images

ECHOCARDIOGRAPHY, Issue 2 2006
J. Manivannan M.E.
Objectives: We sought to quantify the left ventricle systolic dysfunction by a geometric index from two-dimensional (2D) echocardiography by implementing an automated fuzzy logic edge detection algorithm for the segmentation. Background: The coronary injuries have repercussions on the left ventricle producing changes on wall contractility, the shape of the cavity, and as a whole changes on the ventricular function. Methods: 2D echocardiogram and M-mode recordings were performed over the control group and those with the dysfunctions. From 2D recordings, individual frames were extracted for at least five cardiac cycles and then segmentation of left ventricle was done by automated fuzzy systems. In each frame, the volumes are measured and a geometric index, eccentricity ratio (ER), was derived. The endocardial fractional shortening (FS), midwall fractional shortening (mFS), and the relative wall thickness (RWT) were also measured in each case. Results: Depressed value of endocardial FS (20.39 ± 5.43 vs 34.28 ± 9.36, P = 0.0046), mFS (33 ± 8.3 vs 52.5 ± 11.7, P = 0.0047), and the RWT (0.337 ± 0.096 vs 0.525 ± 0.119, P = 0.0002) was observed with dysfunction. ER measured at end-diastole (2.86 ± 0.703 vs 4.14 ± 0.38) and end-systole (3.14 ± 0.79 vs 5.48 ± 0.74) was found to be decreased in the dysfunction group and more significant at the end-systole (P = 0.00017 vs 6.6E,06). Conclusion: This work concludes that the regional and global left ventricle systolic dysfunction can be assessed by the ER measured at end-diastole and end-systole from 2D echocardiogram and may contribute to the high rate of cardiovascular disorders. [source]

Morphometric and Quantitative Evaluation of the NADH-Diaphorase Positive Myenteric Neurons of the Jejunum of Streptozotocin-Diabetic Rats Supplemented with Acetyl-L-Carnitine

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2005
M. H. de Miranda Neto
Summary In this study we investigated the effect of the acetyl-L-carnitine (ALC) supplementation on the myenteric neurons of the jejunum of rats made diabetic at the age of 105 days by streptozotocin (35 mg/kg body weight). Four groups were used: non-diabetic (C), non-diabetic supplemented with ALC (CC), diabetic (D), diabetic supplemented with ALC (DC). After 15 weeks of diabetes induction the blood was collected by cardiac puncture to evaluate glycaemia and glycated haemoglobin. Next the animals were killed and the jejunum was collected and subjected to whole-mount preparation to evidence the myenteric neurons through the histochemical technique of the NADH-diaphorase. The neuronal counts were made in 80 microscopic fields, in tissue samples of five animals of each group. The profiles of the cell bodies of 1000 neurons per group were analysed. Diabetes induced a significant increase in the area of the cell body and decrease in the number of NADH-diaphorase positive myoenteric neurons. ALC suplementation to the diabetic group promoted smaller hypertrophic effects and less neuronal loss than in the myoenteric neurons of the diabetic rats, and in addition diminished the body weight decrease and reduced the fasting glycaemia. [source]

A Bowl-Shaped ortho -Semiquinone Radical Anion: Quantitative Evaluation of the Dynamic Behavior of Structural and Electronic Features,

ANGEWANDTE CHEMIE, Issue 36 2010
Akira Ueda Dr.
Elegant aufgetischt: Das erste ,schüsselförmige" o -Semichinonradikal (siehe Bild; mit einem Na+ -Ion) wurde synthetisiert und bezüglich seiner elektronischen Eigenschaften charakterisiert. Das dynamische Verhalten (konkav,konvex) wurde mit EPR- und ENDOR/TRIPLE-Messungen sowie DFT-Rechnungen ebenfalls quantitativ untersucht. [source]

Quantitative evaluation of morpholino-mediated protein knock down of GFP, MSX1, and PAX7 during tail regeneration in Ambystoma mexicanum

DEVELOPMENTAL DYNAMICS, Issue 3 2005
Esther Schnapp
No abstract is available for this article. [source]

Quantitative evaluation of sample application methods for semipreparative separations of basic proteins by two-dimensional gel electrophoresis

ELECTROPHORESIS, Issue 19-20 2003
Richard C. Barry
Abstract The use of cup-loading for sample application has become widely used in two-dimensional electrophoresis (2-DE) for resolution of basic proteins, but no side-by-side quantitative study has been published which compares cup-loading with the alternative passive and active rehydration methods to fully promote one type of loading method over another. Replicate 2-D gels from each loading method were quantitatively evaluated for gel-to-gel reproducibility using IPG 6,11 strips and semipreparative protein loads (300 ,g). Gels were stained with SYPRO Ruby and analyzed with PDQuest. An inexpensive home-made assembly for cup-loading was used with the Protean IEF Cell for separation of whole cell extracts from the archaeon, Sulfolobus solfataricus. Cup-loading was determined to be far superior for IPG 6,11 separations than active or passive rehydration methods. Cup-loading consistently produced the greatest number of detectable spots, the best spot matching efficiency (56%), lowest spot quantity variations (28% coefficient of variation, CV), and the best-looking gels qualitatively. The least satisfactory results were obtained with active rehydration, followed closely by passive rehydration in off-line tubes. Passive rehydration experiments, performed using an on-line isoelectric focusing (IEF) tray, produced comparable spot numbers to cup-loading (84%), with 55% of the spots having higher intensity but 10% more spot quantity variance than cup-loading. [source]

Scintigraphic examination of the cartilages of the foot

EQUINE VETERINARY JOURNAL, Issue 3 2007
A. NAGY
Summary Reasons for performing study: Radiographic examination of the cartilages of the foot is well documented; however, there is limited information about their scintigraphic assessment. Objectives: To evaluate the scintigraphic appearance of the cartilages of the foot using subjective and quantitative image analysis and to correlate radiographic and scintigraphic findings. Hypotheses: An ossified cartilage would have similar radiopharmaceutical uptake (RU) to the ipsilateral aspect of the distal phalanx; RU would extend throughout the length of the ossified cartilage; a separate centre of ossification (SCO) would be identified on a scintigraphic image; and fracture or trauma to an ossified cartilage would manifest as increased RU (IRU). Methods: Front feet (n = 223) of horses (n = 186) that had dorsopalmar radiographic views and dorsal scintigraphic images were included in the study. The cartilages of the foot were graded radiographically and scintigraphically. Quantitative evaluation of the scintigraphic images was carried out using region of interest (ROI) analysis. For statistical analysis RU ratios were used. Correlations between a radiographically detected SCO and focal RU and between IRU and radiographic abnormalities were assessed. Results: There was a good correlation and an excellent agreement between radiographic and scintigraphic grades. ROI analysis showed a proximal to distal increase in RU ratios within each cartilage of the foot. A radiographically identified SCO could be detected scintigraphically in 12/17 feet (70.6%). Thirty-eight feet had IRU in the region of a cartilage, 25 of which (65.8%) had corresponding radiographic abnormalities. Fracture of an ossified cartilage was associated with IRU in all horses. Conclusions and potential relevance: Scintigraphy may give information about the potential clinical significance of ossification of the cartilages of the foot and associated lesions, therefore prompting further investigation by use of a uniaxial ipsilateral palmar nerve block and imaging, using either magnetic resonance imaging and/or computed tomography. [source]

Quantitative evaluation of severity in psoriatic lesions using three-dimensional morphometry

EXPERIMENTAL DERMATOLOGY, Issue 4 2004
Sang Yong Park
Abstract:, The severity of psoriasis has been traditionally assessed by measures, such as the psoriasis area and severity index (PASI), the psoriasis severity scores, and the lesional severity scores. As a result, even experienced dermatologists show variations when attempting to determine the severity of psoriasis. Therefore, a better non-invasive and objective measurement of clinical signs is needed. In this study, an instrument, a so-called ,stereoimage optical topometer' (SOT), based on a new concept of ,stereoimaging' was used to measure the three-dimensional skin surface. The aim of this study was to compare the results obtained by the SOT with the visual score of psoriasis lesion. Thirty psoriatic patients were enrolled in this study. Initially, the severity of the infiltration and the scale of 134 psoriatic lesions were assessed by using a visual scoring system (0: none, 1: mild, 2: moderate, 3: severe, and 4: very severe), as scored by five dermatologists. The SOT was then used to quantify the severity of each psoriatic lesion using four three-dimensional SOT parameters (Sa, SL, SA, and SV). Secondly, the involved skin-surface area in the psoriasis cases was scored by the naked eye by the five dermatologists and by image analysis. Statistically significant differences were observed between grades 0, 1, 2, and 3 in terms of the severity measurements of the individual psoriatic lesions by SOT when using the parameters Sa, SL, SA, and SV. Therefore, it was concluded that there is a strong correlation between the results measured by visual scoring and by SOT in psoriasis. [source]

Non-destructive evaluation of fatigue and creep-fatigue damage by means of the induced-current focused potential drop technique

FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 12 2001
Y. Sato
Quantitative evaluation of damage accumulation including crack initiation and propagation is one of the major concerns of industrial plant management and plant licence renewal. In order to develop a novel non-destructive testing (NDT) and non-destructive evaluation (NDE) technique for damage evaluation, the induced-current focused potential drop (ICFPD), originally proposed for a defect inspection, was employed. In this study, ICFPD was successfully applied to a non-destructive damage evaluation based on crack measurements. The measurements were taken on fatigued specimens with various degrees of fatigue damage. The ICFPD can clearly detect and differentiate the damage accumulation processes including crack initiation, small crack growth and subsequent macroscopic crack growth. In order to demonstrate the applicability of damage evaluation assessments based on small crack measurements, ICFPD has also been applied to creep,fatigue loading where damage evaluation of a fusion reactor material is based on small crack measurements by the ICFPD technique and a novel methodology is proposed. [source]

Quantitative evaluation of automated skull-stripping methods applied to contemporary and legacy images: Effects of diagnosis, bias correction, and slice location

HUMAN BRAIN MAPPING, Issue 2 2006
Christine Fennema-Notestine
Abstract Performance of automated methods to isolate brain from nonbrain tissues in magnetic resonance (MR) structural images may be influenced by MR signal inhomogeneities, type of MR image set, regional anatomy, and age and diagnosis of subjects studied. The present study compared the performance of four methods: Brain Extraction Tool (BET; Smith [2002]: Hum Brain Mapp 17:143,155); 3dIntracranial (Ward [1999] Milwaukee: Biophysics Research Institute, Medical College of Wisconsin; in AFNI); a Hybrid Watershed algorithm (HWA, Segonne et al. [2004] Neuroimage 22:1060,1075; in FreeSurfer); and Brain Surface Extractor (BSE, Sandor and Leahy [1997] IEEE Trans Med Imag 16:41,54; Shattuck et al. [2001] Neuroimage 13:856,876) to manually stripped images. The methods were applied to uncorrected and bias-corrected datasets; Legacy and Contemporary T1 -weighted image sets; and four diagnostic groups (depressed, Alzheimer's, young and elderly control). To provide a criterion for outcome assessment, two experts manually stripped six sagittal sections for each dataset in locations where brain and nonbrain tissue are difficult to distinguish. Methods were compared on Jaccard similarity coefficients, Hausdorff distances, and an Expectation-Maximization algorithm. Methods tended to perform better on contemporary datasets; bias correction did not significantly improve method performance. Mesial sections were most difficult for all methods. Although AD image sets were most difficult to strip, HWA and BSE were more robust across diagnostic groups compared with 3dIntracranial and BET. With respect to specificity, BSE tended to perform best across all groups, whereas HWA was more sensitive than other methods. The results of this study may direct users towards a method appropriate to their T1 -weighted datasets and improve the efficiency of processing for large, multisite neuroimaging studies. Hum. Brain Mapping, 2005. © 2005 Wiley-Liss, Inc. [source]

Quantitative evaluation of strategies for erosion control on a railway embankment batter

HYDROLOGICAL PROCESSES, Issue 17 2001
Y. Gyasi-Agyei
Abstract Strategies for erosion control on a railway embankment batter (side slope) are quantitatively evaluated in this paper. The strategies were centred on control (,do nothing' treatment), grass seeding, gypsum application, jute mat (an erosion control blanket) placement and planting hedgerows of Monto vetiver grass. Rainfall and runoff were monitored at 1 min intervals on 10 m wide embankment batter plots during 1998 and 1999. Total bedload and suspended sediment eroded from the plots were also measured but only for a group of storm events within sampling intervals. It has been demonstrated that vetiver grass is not cost-effective in controlling erosion on railway batters within Central Queensland region. Seeding alone could cause 60% reduction in the erosion rate compared with the control treatment. Applying gypsum to the calcium-deficient soil before seeding yielded an additional 25% reduction in the erosion rate. This is the result, primarily, of 100% grass cover establishment within seven months of sowing. Therefore, for railway embankment batter erosion control, the emphasis needs to be on rapid establishment of 100% grass cover. For rapid establishment of grass cover, irrigation is necessary during the initial stages of growth as the rainfall is unpredictable and the potential evaporation exceeds rainfall in the study region. The risk of seeds and fertilizers being washed out by short-duration and high-intensity rainfall events during the establishment phase may be reduced by the use of erosion control blankets on sections of the batters. Accidental burning of grasses on some plots caused serious erosion problems, resulting in very slow recovery of grass growth. It is therefore recommended that controlled burning of grasses on railway batters should be avoided to protect batters from being exposed to severe erosion. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Quantitative evaluation of DNA hypermethylation in malignant and benign breast tissue and fluids

INTERNATIONAL JOURNAL OF CANCER, Issue 2 2010
Weizhu Zhu
Abstract The assessment of DNA had demonstrated altered methylation in malignant compared to benign breast tissue. The purpose of our study was to (i) confirm the predictive ability of methylation assessment in breast tissue, and (ii) use the genes found to be cancer predictive in tissue to evaluate the diagnostic potential of hypermethylation assessment in nipple aspirate fluid (NAF) and mammary ductoscopic (MD) samples. Quantitative methylation specific (qMS)-PCR was conducted on three specimen sets: 44 malignant (CA) and 34 normal (NL) tissue specimens, 18 matched CA, adjacent normal (ANL) tissue and NAF specimens, and 119 MD specimens. Training and validation tissue sets were analyzed to determine the optimal group of cancer predictive genes for NAF and MD analysis. NAF and MD cytologic review were also performed. Methylation of CCND -2, p16, RAR -, and RASSF-1a was significantly more prevalent in tumor than in normal tissue specimens. Receiver operating characteristic curve analysis demonstrated an area under the curve of 0.96. For the 18 matched CA, ANL and NAF specimens, the four predictive genes identified in cancer tissue contained increased methylation in CA vs. ANL tissue; NAF samples had higher methylation than ANL specimens. Methylation frequency was higher in MD specimens from breasts with cancer than benign samples for p16 and RASSF-1a. In summary, i) routine quantitative DNA methylation assessment in NAF and MD samples is possible, and ii) genes hypermethylated in malignant breast tissue are also altered in matched NAF and in MD samples, and may be useful to assist in early breast cancer detection. [source]

Quantitative evaluation of the prosthetic head damage induced by microscopic third-body particles in total hip replacement

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 4 2001
Manuela Teresa Raimondi
Abstract The increase of the femoral head roughness in artificial hip joints is strongly influenced by the presence of abrasive particulate entrapped between the articulating surfaces. The aim of the present study is to evaluate the dependence of such damage on the geometry of the particles entrapped in the joint, with reference to the UHMWPE/chrome-cobalt coupling. Five chrome-cobalt femoral heads and their coupled UHMWPE acetabular cups, retrieved at revision surgery after a short period of in situ functioning, have been investigated for the occurrence of third-body damage. This was found on all the prosthetic heads, where the peak-to-valley height of the scratches, as derived from profilometry evaluations, ranged from 0.3,1.3 ,m. The observed damage has been divided into four classes, related to the particle motion while being embedded into the polymer. Two kinds of particle morphology have been studied, spherical and prismatic, with size ranging from 5,50 ,m. In order to provide an estimation of the damage induced by such particles, a finite element model of the third-body interaction was set up. The peak-to-valley height of the impression due to the particle indentation on the chrome-cobalt surface is assumed as an index of the induced damage. The calculated values range from 0.1,0.5 ,m for spherical particles of size ranging from 10,40 ,m. In the case of prismatic particles, the peak-to-valley height can reach 1.3 ,m and depends both on the size and width of the particle's free corner, indenting the chrome-cobalt. As an example, a sharp-edged particle of size 30 ,m can induce on the chrome-cobalt an impression with peak-to-valley height of 0.75 ,m, when embedded into the polyethylene with a free edge of 5 ,m facing the metallic surface. Negligible damage is induced, if a free edge of 7.5 ,m is indenting the counterface. Our findings offer new support to the hypothesis that microscopic third-body particles are capable of causing increased roughening of the femoral head and provide a quantitative evaluation of the phenomenon. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 436,448, 2001 [source]

Characterization of Tissue Transglutaminase in Human Osteoblast-like Cells

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 8 2001
Deborah J. Heath
Abstract Tissue transglutaminase (tTG) is a calcium-dependent and guanosine 5,-triphosphate (GTP) binding enzyme, which catalyzes the post-translational modification of proteins by forming intermolecular ,(,-glutamyl)lysine cross-links. In this study, human osteoblasts (HOBs) isolated from femoral head trabecular bone and two osteosarcoma cell lines (HOS and MG-63) were studied for their expression and localization of tTG. Quantitative evaluation of transglutaminase (TG) activity determined using the [1,414C]-putrescine incorporation assay showed that the enzyme was active in all cell types. However, there was a significantly higher activity in the cell homogenates of MG-63 cells as compared with HOB and HOS cells (p < 0.001). There was no significant difference between the activity of the enzyme in HOB and HOS cells. All three cell types also have a small amount of active TG on their surface as determined by the incorporation of biotinylated cadaverine into fibronectin. Cell surface-related tTG was further shown by preincubation of cells with tTG antibody, which led to inhibition of cell attachment. Western blot analysis clearly indicated that the active TG was tTG and immunocytochemistry showed it be situated in the cytosol of the cells. In situ extracellular enzyme activity also was shown by the cell-mediated incorporation of fluorescein cadaverine into extracellular matrix (ECM) proteins. These results clearly showed that MG-63 cells have high extracellular activity, which colocalized with the ECM protein fibronectin and could be inhibited by the competitive primary amine substrate putrescine. The contribution of tTG to cell surface/matrix interactions and to the stabilization of the ECM of osteoblast cells therefore could by an important factor in the cascade of events leading to bone differentiation and mineralization. [source]

Quantitative evaluation of prostatectomy for benign prostatic hypertrophy under a national health insurance law: a multi-centre study

JOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 1 2002
D. Pilpel PhD
Abstract Assessing regional variation between various medical centres in diagnostic and surgical processes is an approach aimed at evaluating the quality of care. This study analyses the differences between eight medical centres in Israel, where all citizens are covered by medical insurance, through the National Health Insurance Law (NHIL). The analysis refers to the diagnostic process, type of surgery and immediate post-surgical complications associated with prostatectomy for benign prostatic hypertrophy (BPH), which is the most frequent surgical procedure performed on men aged 50+. The study sample was comprized of 261 consecutive prostatectomy patients operated on in eight Israeli medical centres (MC), located in various parts of the country, between November 1996 and April 1997. Co-operation with participating directors of surgical wards was obtained after confidentiality of information had been assured. Surgeons in selected departments abstracted data routinely recorded in the patient's file and filled-out a standard one-page questionnaire. The following items were included: age, the presence of accompanying chronic diseases, preoperative tests, type of operation, and post-surgical complications. In the various MCs 32.6% of the patients underwent more than five preoperative tests ranging from 8.9% to 88.9% (<0.01). Assessment of kidney and bladder normality ranged from 75% to 100% (P < 0.01). The rate of patients whose prostatic symptoms (I-PSS) were assessed ranged from 0% to 79% (P < 0.01). There were also differences in severity of prostatism between the MCs, with severe symptoms ranging from 54.0% to 89.3% (P < 0.05), for type of operation performed (for ,open' prostatectomies, 35.4% to 68.0%, P < 0.01) and post-operative complications (19.0% to 41.6%, P = 0.07). After controlling for case-mix, type of operation was the most important predictor for post-surgical complications. MCs with low volume of surgeries had a higher rate of postoperative complications. We conclude that diagnostic and type of operation and post-surgical complications differed between various MCs. Participating surgeons were willing to fill out a one-page standard questionnaire from data routinely recorded in patients' files. [source]

Diffusion-weighted imaging of the liver: Comparison of navigator triggered and breathhold acquisitions

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2009
Bachir Taouli MD
Abstract Purpose To compare a free breathing navigator triggered single shot echoplanar imaging (SS EPI) diffusion-weighted imaging (DWI) sequence with prospective acquisition correction (PACE) with a breathhold (BH) DWI sequence for liver imaging. Materials and Methods Thirty-four patients were evaluated with PACE-DWI and BH DWI of the liver using b-values of 0, 50, and 500 s/mm2. There were 29 focal liver lesions in 18 patients. Qualitative evaluation was performed on a 3-point scale (1,3) by two independent observers (maximum score 9). Quantitative evaluation included estimated SNR (signal to noise ratio), lesion-to-liver contrast ratio, liver and lesion apparent diffusion coefficients (ADCs), and coefficient of variation (CV) of ADC in liver parenchyma and focal liver lesions (estimate of noise contamination in ADC). Results PACE-DWI showed significantly better image quality, higher SNR and lesion-to-liver contrast ratio when compared with BH DWI. ADCs of liver and focal lesions with both sequences were significantly correlated (r = 0.838 for liver parenchyma, and 0.904 for lesions, P < 0.0001), but lower with the BH sequence (P < 0.02). There was higher noise contamination in ADC measurement obtained with BH DWI (with a significantly higher SD and CV of ADC). Conclusion The use of a navigator echo to trigger SS EPI DWI improves image quality and liver to lesion contrast, and enables a more precise ADC quantification compared with BH DWI acquisition. J. Magn. Reson. Imaging 2009;30:561,568. © 2009 Wiley-Liss, Inc. [source]

Guidelines for using quantitative magnetization transfer magnetic resonance imaging for monitoring treatment of multiple sclerosis,

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 4 2003
Mark A. Horsfield PhD
Abstract Quantitative evaluation of brain magnetic resonance imaging (MRI) scans is now an accepted part of the trial of new putative treatments for multiple sclerosis (MS). However, conventional MRI is not pathologically specific, and it does not reveal the details of the pathological processes that underlie the progression of the disease. Magnetization transfer (MT) imaging is a relatively new quantitative technique that appears to offer some pathological specificity, and can be used to monitor the changes over time in both individual lesions and the central nervous system as a whole. This paper considers the case for incorporating MT imaging into new clinical trials, so that the utility of MT for monitoring the modification of MS progression by treatment can be assessed. Specific guidelines for implementing MT imaging as part of a large multicenter clinical trial are given, and practical considerations when planning such a trial are detailed. It is anticipated that MT imaging will be incorporated into many new trials in the near future. J. Magn. Reson. Imaging 2003;17:389,397. © 2003 Wiley-Liss, Inc. [source]

Quantitative evaluation of Enterocytozoon bieneusi infection in simian immunodeficiency virus-infected rhesus monkeys

JOURNAL OF MEDICAL PRIMATOLOGY, Issue 2 2003
K. Sestak
Abstract: The association of the microsporidia Enterocytozoon bieneusi with chronic diarrhea and wasting in individuals with acquired immunodeficiency syndrome (AIDS) has been demonstrated. The disease caused by E. bieneusi has been linked to decreased levels of circulating CD4+ T lymphocytes. In this study, we investigated the relationship between the extent of excretion of E. bieneusi in feces of simian immunodeficiency virus (SIV)-infected juvenile macaques and the CD4+ T lymphocyte counts in the peripheral blood. Twelve juvenile rhesus monkeys (Macaca mulatta) were intravenously inoculated with the pathogenic molecular clone SIVmac239. Numbers of CD4+ T lymphocytes were assessed by three-color flow cytometry. The presence of E. bieneusi DNA in feces was assessed by nested PCR. In addition, selected samples of feces were examined by competitive quantitative PCR to assess the level of E. bieneusi infection. Low (n = 5) to undetectable (n = 7) quantities of E. bieneusi were present in feces of the twelve animals in prior to inoculation with SIV. After SIV inoculation the number of animals shedding E. bieneusi increased (n = 10) as did the quantity of E. bieneusi shedding in the feces. Of the twelve juvenile animals, five animals died within 8 months post-SIV inoculation with symptoms of AIDS. Four of the five deceased animals showed shedding of E. bieneusi DNA in feces (,100 spores/g) for at least three consecutive months. Increased number of E. bieneusi in feces was accompanied by decreased counts of circulating CD4+ T lymphocytes and increased SIV plasma viral load. [source]

Quantitative evaluation of the interaction between netropsin and double stranded oligodeoxynucleotides by microfabricated capillary array electrophoresis

JOURNAL OF SEPARATION SCIENCE, JSS, Issue 10 2007
Zheng Shen
Abstract Microfabricated capillary array electrophoresis (,-CAE) was applied to study the interaction between minor groove binder netropsin and a non-selfcomplementary 12 mer double stranded oligodeoxynucleotide: d(CCCCTATACCGC)·d(GCGGTATAGGGG). ESI-MS was used to provide an independent verification of the microchip electrophoresis derived data. Simultaneous parallel quantitative assay of multiple samples was performed in a single run (<50 s) on the self-developed ,-CAE device. The binding constant and stoichiometry calculated from Scatchard plot were (2.88 ± 0.23)×105 M,1 and 1:1, respectively. The values showed a good quantitative agreement with the results determined by ESI-MS and those using other methods reported in the literature. [source]

EXAFS study of local atomic order about iodine in thyroxine, rat, human and sheep thyroids

JOURNAL OF SYNCHROTRON RADIATION, Issue 6 2008
B. R. Orton
Radioactive 125I emits short-range Auger electrons and represents a human health risk when incorporated in thyroglobulin of the thyroid. Quantitative evaluation of this risk can only be realised if local atomic order about iodine in the thyroid is known. Here, extended X-ray absorption fine structure (EXAFS) has been used to probe the local structure about iodine in pure thyroid hormone, thyroxine. These data are consistent with a model where iodine is bound to a single iodinated carbon ring linked to an oxygen atom, similar to a previously published model for monoiodotyrosine, a major iodinated residue in thyroglobulin. Several structural models for the local environment of iodine from rat, human and sheep have been tested and these data are found to be compatible with a slightly modified environment with respect to that found for thyroxine. The best-fit models include the following three components: (i) iodine covalently bonded to a tyrosine ring, as found for thyroxine; (ii) iodine bonded quasi-covalently to a carbonyl ligand in partially filled (50%) sites; (iii) partially filled sites (50,40%) of carbonyl ligands, with oxygen at van der Waals distances from iodine. Advantages of using Fourier-filtered EXAFS for complex crystal structures are discussed. [source]

Quantitative evaluation of susceptibility and shielding effects of nitinol, platinum, cobalt-alloy, and stainless steel stents

MAGNETIC RESONANCE IN MEDICINE, Issue 5 2003
Yi Wang
Abstract The purpose of this study is to quantitatively estimate the shielding and susceptibility effects of commonly used metallic stents on MR signal. Two experiments were performed using a 3D gradient echo sequence with short TE to image a stent phantom: 1) short TR and high flip angle (contrast enhanced MRA parameters), and 2) long TR (TR , T1) and low flip angle. The factor characterizing susceptibility effects was estimated from the signal phase of the first experiment, and then the factor characterizing the shielding effects was derived from the second experiment. Susceptibility induced signal loss was negligible (<1%) for nonstainless-steel (nitinol, platinum, and cobalt-alloy) stents and totally destructive (100%) for the stainless steel stent. Signal loss due to RF shielding was 31,62% for nitinol stents, 14,50% for platinum stents, 50,77% for the cobalt-alloy stents (undetermined for the stainless steel stent), varied with stent orientation, diameter, and wall geometry. In summary, stents made of nitinol, platinum, and cobalt-alloy have negligible susceptibility effects but stents made of stainless steel may have complete dephasing. All stents have substantial shielding effects, which vary with composition, geometry, and orientation. Large platinum stents may have the smallest artifacts and are the best suited for postinterventional MR imaging. Magn Reson Med 49:972,976, 2003. © 2003 Wiley-Liss, Inc. [source]

Condensation and aggregation of solar corundum and corundum-hibonite grains

METEORITICS & PLANETARY SCIENCE, Issue 7-8 2007
T. M. Nakamura
Some of the corundum and corundum-hibonite grains occur as aggregates of 2 to 6 grains having similar sizes. The oxygen isotopic compositions of some of the corundum-bearing grains suggest their solar nebula origin. 26Al- 26Mg systematics of one corundum grain showed the canonical initial 26Al/27Al ratio, also suggesting a solar nebula origin. Quantitative evaluation of condensation and accretion processes made based on the homogeneous nucleation of corundum, diffusion-controlled hibonite formation, collisions of grains in the nebula, and critical velocity for sticking, indicates that, in contrast to the hibonite-bearing aggregates of corundum grains, the hibonite-free corundum aggregates could not have formed in the slowly cooling nebular region with solar composition. We suggest instead that such aggregates formed near the protosun, either in a region that stayed above the condensation temperature of hibonite for a long time or in a chemically fractionated, Ca-depleted region, and were subsequently physically removed from this hot region, e.g., by disk wind. [source]

Three-dimensional spatial interpolation of surface meteorological observations from high-resolution local networks

METEOROLOGICAL APPLICATIONS, Issue 3 2008
Francesco Uboldi
Abstract An objective analysis technique is applied to a local, high-resolution meteorological observation network in the presence of complex topography. The choice of optimal interpolation (OI) makes it possible to implement a standard spatial interpolation algorithm efficiently. At the same time OI constitutes a basis to develop, in perspective, a full multivariate data assimilation scheme. In the absence of a background model field, a simple and effective de-trending procedure is implemented. Three-dimensional correlation functions are used to account for the orographic distribution of observing stations. Minimum-scale correlation parameters are estimated by means of the integral data influence (IDI) field. Hourly analysis fields of temperature and relative humidity are routinely produced at the Regional Weather Service of Lombardia. The analysis maps show significant informational content even in the presence of strong gradients and infrequent meteorological situations. Quantitative evaluation of the analysis fields is performed by systematically computing their cross validation (CV) scores and by estimating the analysis bias. Further developments concern the implementation of an automatic quality control procedure and the improvement of error covariance estimation. Copyright © 2008 Royal Meteorological Society [source]

Quantitative evaluation of bone resorption activity of osteoclast-like cells by measuring calcium phosphate resorbing area using incubator-facilitated and video-enhanced microscopy

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 4 2009
Yoshitaka Morimoto
Abstract Quantitative evaluation of the ability of bone resorption activity in live osteoclast-like cells (OCLs) has not yet been reported on. In this study, we observed the sequential morphological change of OCLs and measured the resorbing calcium phosphate (CP) area made by OCLs alone and with the addition of elcatonin utilizing incubator facilitated video-enhanced microscopy. OCLs, which were obtained from a coculture of ddy-mouse osteoblastic cells and bone marrow cells, were cultured on CP-coated quartz cover slips. The CP-free area increased constantly in the OCLs alone, whereas it did not increase after the addition of elcatonin. This study showed that analysis of the resorbed areas under the OCL body using this method enables the sequential quantitative evaluation of the bone resorption activity and the effect of several therapeutic agents on bone resorption in vitro. Microsc. Res. Tech, 2009. © 2008 Wiley-Liss, Inc. [source]

Exploring the third dimension in root resorption

ORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 2 2004
EKM Chan
Structured Abstract Authors , Chan EKM, Darendeliler MA Objective , To review and investigate the validity of various 2D quantitative measurement techniques, and to explore the third dimension of root resorption. Design , A review of the literature involving various quantitative evaluation of root resorption. Results , Quantitative evaluation of resorption using radiographs has proven to be highly inaccurate because of magnification errors and their inability to be readily repeated and reproduced. Studies using histology sections of samples have proven to be laborious and technique sensitive. Inherent parallax errors and loss of material in data transfer have denied the true understanding of this 3D event. Conclusion , With the evolution in computing technology and digital imaging, the vision of evaluating the extent of root resorption in 3D has materialized. It was demonstrated that 3D volumetric quantitative evaluation of root resorption craters was feasible and its accuracy and repeatability was high. [source]

Quantitative evaluation of the atomic structure of defects and composition fluctuations at the nanometer scale inside InGaN/GaN heterostructures

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 12 2004
P. Ruterana
Abstract Investigation is carried out by high-resolution electron microscopy on threading dislocations using data treatments with procedures that allow the extraction of the most likely atomic configurations. We also report In composition fluctuations inside InGaN/GaN quantum wells by coupling HRTEM, image simulation and Finite Element Modelling (FEM) of the thin foil relaxation. The results show that the indium content may be close to x = 1.0 in the clusters and this is much higher that was previously suggested by 2D FEM modelling. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Quantitative evaluation of shunts in solar cells by lock-in thermography

PROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 8 2003
O. Breitenstein
Abstract Infrared lock-in thermography allows to image shunts very sensitively in all kinds of solar cells and also to measure dark currents flowing in certain regions of the cell quantitatively. After a summary of the physical basis of lock-in thermography and its practical realization, four types of quantitative measurements are described: local I,V characteristics measured thermally up to a constant factor (LIVT); the quantitative measurement of the current through a local shunt; the evaluation of the influence of shunts on the efficiency of a cell as a function of the illumination intensity; and the mapping of the ideality factor n and the saturation current density J0 over the whole cell. The investigation of a typical multicrystalline solar cell shows that the shunts are predominantly responsible for deterioration of the low-light-level performance of the cell, and that variations of the injection current density related to crystal defects are predominantly determined by variation of J0 rather than of n. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Quantitative evaluation of the lengths of homobifunctional protein cross-linking reagents used as molecular rulers

PROTEIN SCIENCE, Issue 7 2001
Nora S. Green
Abstract Homobifunctional chemical cross-linking reagents are important tools for functional and structural characterization of proteins. Accurate measures of the lengths of these molecules currently are not available, despite their widespread use. Stochastic dynamics calculations now provide quantitative measures of the lengths, and length dispersions, of 32 widely used molecular rulers. Significant differences from published data have been found. [source]

Quantitative evaluation of marine protein contribution in ancient diets based on nitrogen isotope ratios of individual amino acids in bone collagen: An investigation at the Kitakogane Jomon site

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2010
Yuichi I. Naito
Abstract Nitrogen stable isotopes analysis of individual bone collagen amino acids was applied to archeological samples as a new tool for assessing the composition of ancient human diets and calibrating radiocarbon dates. We used this technique to investigate human and faunal samples from the Kitakogane shell midden in Hokkaido, Japan (5,300,6,000 cal BP). Using compound-specific nitrogen isotope analysis of individual amino acids, we aimed to estimate i) the quantitative contribution of marine and terrestrial protein to the human diet, and ii) the mean trophic level (TL) from which dietary protein was derived from marine ecosystems. Data were interpreted with reference to the amino acid trophic level (TLAA) model, which uses empirical amino acid ,15N from modern marine fauna to construct mathematical equations that predict the trophic position of organisms. The TLAA model produced realistic TL estimates for the Kitakogane marine animals. However, this model was not appropriate for the interpretation of human amino acid ,15N, as dietary protein is derived from both marine and terrestrial environments. Hence, we developed a series of relevant equations that considered the consumption of dietary resources from both ecosystems. Using these equations, the mean percentage of marine protein in the Kitakogane human diet was estimated to be 74%. Although this study is one of the first systematic investigations of amino acid ,15N in archeological bone collagen, we believe that this technique is extremely useful for TL reconstruction, palaeodietary interpretation, and the correction of marine reservoir effects for radiocarbon dating. Am J Phys Anthropol 143:31,40, 2010. © 2010 Wiley-Liss, Inc. [source]

A robotic system for crystallizing membrane and soluble proteins in lipidic mesophases

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 10 2004
Vadim Cherezov
A high-throughput robotic system has been developed for crystallizing membrane proteins using lipidic mesophases. It incorporates commercially available components and is relatively inexpensive. The crystallization robot uses standard automated liquid-handlers and a specially built device for accurately and reproducibly delivering nanolitre volumes of highly viscous protein/lipid mesophases. Under standard conditions, the robot uses just 20,nl protein solution, 30,nl lipid and 1,µl precipitant solution. 96 wells can be set up using the robot in 13,min. Trials are performed in specially designed 96-well glass plates. The slim (<2,mm high) plates have exquisite optical properties and are well suited for the detection of microcrystals and for birefringence-free imaging between crossed polarizers. Quantitative evaluation of the crystallization progress is performed using an automated imaging system. The optics, in combination with the slim crystallization plates, enables in-focus imaging of the entire well volume in a single shot such that a 96-well plate can be imaged in just 4.5,min. The performance characteristics of the robotic system and the versatility of the crystallization robot in performing vapor-diffusion, microbatch and bicelle crystallizations of membrane and soluble proteins are described. [source]

Fluvial response to sea-level changes: a quantitative analogue, experimental approach

BASIN RESEARCH, Issue 3 2001
M. W. I. M. Van Heijst
ABSTRACT Quantitative evaluation of fluvial response to allogenic controls is crucial for further progress in understanding the stratigraphic record in terms of processes that control landscape evolution. For instance, without quantitative insight into time lags that are known to exist between sea-level change and fluvial response, there is no way to relate fluvial stratigraphy to the sea-level curve. It is difficult to put firm constraints on these time-lag relationships on the basis of empirical studies. Therefore, we have started to quantify time-averaged erosion and deposition in the fluvial and offshore realms in response to sea-level change by means of analogue modelling in a 4 × 8-m flume tank. The rate of sea-level change was chosen as an independent variable, with other factors such as sediment supply, discharge and initial geometry kept constant over the course of 18 experiments. Our experimental results support the common view that neither fall nor rise in sea level affects the upstream fluvial system instantaneously. An important cause for the delayed fluvial response is that a certain amount of time is required to connect initial incisions on the newly emergent shelf (canyons) with the fluvial valley. Lowering of the fluvial longitudinal profile starts only after the connection of an active shelf canyon with the fluvial valley; until that moment the profile remains steady. We quantified the process of connection and introduced the quantity ,connection rate'. It controlled, in conjunction with the rate of sea-level fall: (1) the amount of fluvial degradation during sea-level fall; (2) the total sediment volume that bypasses the shelf edge; (3) the percentage of fluvial relative to shelf sediment in the lowstand delta; (4) the volume of the transgressive systems tract and (5) the amount of diachroneity along the sequence boundary. Our experiments demonstrate also that the sequence-stratigraphic concept is difficult to apply to continental successions, even when these successions have been deposited within the influence of sea level. [source]