Correlation Study (correlation + study)

Distribution by Scientific Domains


Selected Abstracts


A correlation study on diagnostic endoscopic ultrasound-guided fine-needle aspiration of lymph nodes with histological and clinical diagnoses, the UCLA Medical Center experience

DIAGNOSTIC CYTOPATHOLOGY, Issue 7 2008
Bita V. Naini M.D.
Abstract Endoscopic ultrasound guided (EUS) FNA procedure has two aspects, the endoscopic sampling and the FNA interpretation. The two aspects of the procedure are performed in two different disciplines; gastroenterology (EUS) and pathology (FNA). The aim of this study was to evaluate the concordance, sensitivity, specificity, positive predictive (PPV), and negative predictive values (NPV). Sixty-one EUS-FNA procedures of the lymph nodes were analyzed by correlating the FNA results with histological or clinical diagnoses. The lymph nodes were divided in five groups; mediastinal, gastrohepatic, peripancreatic, portal, and perirectal. The study showed a concordance of 92% in mediastinal, 80% in gastrohepatic, 81% in peripancreatic, 95% in portal, and 100% in perirectal lymph nodes with an overall sensitivity of 84%, specificity of 92%, PPV of 88%, and NPV of 89%. In conclusion, EUS-FNA offers an invaluable approach for diagnostic examination of the internal lymph nodes where percutaneous FNA is either difficult or impossible. impossible. Diagn. Cytopathol. 2008;36:460,466. © 2008 Wiley-Liss, Inc. [source]


Subgrouping and grading of soft-tissue sarcomas by fine-needle aspiration cytology: A histopathologic correlation study

DIAGNOSTIC CYTOPATHOLOGY, Issue 5 2001
Hal E. Palmer M.D.
Abstract To evaluate the accuracy and reproducibility of subgrouping and grading soft-tissue sarcomas by fine-needle aspiration biopsy (FNAB), a blind review was conducted of 84 FNAB specimens from 77 malignant and 7 benign soft-tissue lesions. Cytomorphologic subgroups included 31 spindle-cell, 24 pleomorphic, 11 myxoid, 7 epithelioid/polygonal, 3 small round cell, and 8 nondiagnostic cases. Malignancies included one lymphoma and 41 primary, 15 recurrent, and 20 metastatic soft-tissue sarcomas. Adequacy was defined as a majority of slides with at least 5 clusters of 10 unobscured cells. Five originally false-negative cases were considered nondiagnostic on review. Sarcoma was recognized in 59 of 64 adequate cases (92%) with available histology; however, the specific histopathologic subtype was identified in only 9 cases (14%). Benign myxoid and spindle-cell lesions were difficult to separate from low-grade sarcomas in 4 cases, and a B-cell lymphoma with sclerosis mimicked a low-grade myxoid sarcoma. The assigned cytologic grade accurately reflected the histologic grade in 90% of sarcomas when segregated into high and low grades. Pleomorphic, small round cell, and epithelioid/polygonal subgroups corresponded to high-grade sarcomas in all cases with only minor noncorrelations. Major grading noncorrelations occurred in 50% of myxoid and 9% of spindle-cell sarcomas. Therefore, attention should be given to specimen adequacy, and caution should be exercised when attempting to grade myxoid and spindle-cell sarcomas by FNAB. Diagn. Cytopathol. 24:307,316, 2001. © 2001 Wiley-Liss, Inc. [source]


Accumulation of toxic metals (Pb and Cd) in the sea urchin Diadema aff. antillarum Philippi, 1845, in an oceanic island (Tenerife, Canary Islands)

ENVIRONMENTAL TOXICOLOGY, Issue 3 2010
Ofelia Dolores Hernández
Abstract This document shows the results obtained from a study on the concentration of toxic heavy metals in the internal tissue and exoskeleton of sea urchins, collected from their natural habitat. The levels of lead and cadmium were measured by Graphite Furnace Atomic Absorption Spectrometry. The mean concentrations of lead and cadmium in the internal tissue were 304.04 and 260.54 ,g/kg respectively, whereas in the shell they were 185.02 and 142.48 ,g/kg. We also performed a statistical analysis of the differences in the distribution of metals between their exoskeleton and their internal content, a correlation study of the metal content in internal tissue and shell and sampling areas, and a correlation study between the metal content and sample size. Since the sea urchin Diadema antillarum presents a wide range of variation in metal content, this study suggests that this species is an excellent bioindicator of heavy metal contamination. © 2009 Wiley Periodicals, Inc. Environ Toxicol, 2010. [source]


Microstructure-Lattice Thermal Conductivity Correlation in Nanostructured PbTe0.7S0.3 Thermoelectric Materials

ADVANCED FUNCTIONAL MATERIALS, Issue 5 2010
Jiaqing He
Abstract The reduction of thermal conductivity, and a comprehensive understanding of the microstructural constituents that cause this reduction, represent some of the important challenges for the further development of thermoelectric materials with improved figure of merit. Model PbTe-based thermoelectric materials that exhibit very low lattice thermal conductivity have been chosen for this microstructure,thermal conductivity correlation study. The nominal PbTe0.7S0.3 composition spinodally decomposes into two phases: PbTe and PbS. Orderly misfit dislocations, incomplete relaxed strain, and structure-modulated contrast rather than composition-modulated contrast are observed at the boundaries between the two phases. Furthermore, the samples also contain regularly shaped nanometer-scale precipitates. The theoretical calculations of the lattice thermal conductivity of the PbTe0.7S0.3 material, based on transmission electron microscopy observations, closely aligns with experimental measurements of the thermal conductivity of a very low value, ,0.8,W,m,1,K,1 at room temperature, approximately 35% and 30% of the value of the lattice thermal conductivity of either PbTe and PbS, respectively. It is shown that phase boundaries, interfacial dislocations, and nanometer-scale precipitates play an important role in enhancing phonon scattering and, therefore, in reducing the lattice thermal conductivity. [source]


Shadowing correlation assessment and modeling for satellite diversity in urban environments

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 2 2002
M. Vazquez-Castro
Abstract Non-geostationary orbit satellite networks have dynamic, yet deterministic topologies. This paper deals with the consequences of relying on the use of multiple visible satellites to improve availability with time/locations through satellite diversity techniques. The assumption of independent blockage events in two different satellite-to-mobile links is generally not accurate and information on shadowing correlation should be taken into account in the assessment of availability. In this paper a shadowing correlation study for urban environments is presented and a model for the real environments, as well as for a generic urban environment is inferred. The model proposed here is simple and can be run on a computer. It also relates urban and constellation geometries thus allowing the identification of those cases for which satellite diversity gain should be expected. As a result of this analysis and modelling, we present empirical analytical expressions describing positive correlation coefficient as a function of satellite angular separation (azimuth and elevation). We also show that an angle exists above which correlation can be negative and satellite diversity can sensibly improve link availability. Copyright © 2002 John Wiley & Sons, Ltd. [source]


Predictors of Home Healthcare Nurse Retention

JOURNAL OF NURSING SCHOLARSHIP, Issue 2 2008
Carol Hall Ellenbecker
Purpose:To examine the level of job satisfaction and test a theoretical model of the direct and indirect effects of job satisfaction, and individual nurse and agency characteristics, on intent to stay and retention for home healthcare nurses. Design:A descriptive correlation study of home healthcare nurses in six New England states. Methods:Home healthcare nurse job satisfaction self-report data was collected with the HHNJS survey questionnaire & Retention Survey Questionnaire. Findings:Based on a structural equation model, job tenure and job satisfaction were the strongest predictors of nurse retention. Conclusions:Understanding the variables associated with home healthcare nurse retention can help agencies retain nurses in a time of severe nurse shortages and increased patient demand. Clinical Relevance:Predicted nursing shortages and increasing demand have made the retention of experienced, qualified nursing staff essential to assure access to high-quality home healthcare services in the future. [source]


Intraepidermal innervation and tail nerve conduction velocity in neurotoxicity models: results of a correlation study in normal and pathological conditions

JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 2 2004
M Borgna
Animal models of human diseases affecting the peripheral nervous system are widely used to assess the pathogenesis of neurotoxicity and to compare the effect of new agents. Several behavioural, pathological and neurophysiological methods have been used, and each has advantages and disadvantages. A major goal in the study of neurotoxicity would be to assess the damage in the same way in animal models and in humans. In this study we correlated the neurophysiological results obtained in normal rats and in rats treated with cisplatin 2 mg/kg q3d × 8 with the density of intraepidermal fibers (IEF) obtained in skin biopsy specimens. The aim was to investigate the possible role of a minimally invasive procedure such as skin biopsy as an alternative method to assess the peripheral neurotoxicity of antineoplastic drugs. The nerve conduction velocity (NCV) in the tail nerve was assessed in thirty-six young adult female Wistar rats which were left untreated, or treated with erythropoietin (EPO), cisplatin (CDDP) or EPO + CDDP. CDDP and CDDP + EPO-treated rats had a significantly reduced NCV vs. age-matched untreated rats. At sacrifice, skin specimens were obtained. The density of IEF was calculated by 2 independent blinded examiners and the correlation existing between NCV and IEF was highly significant (r = 0.670, p < 0.001). This preliminary result suggests that IEF should be evaluated in other animal models and might represent a useful tool to study peripheral neurotoxicity also in humans. [source]


Knee pain in the ACL-deficient osteoarthritic knee and its relationship to quality of life

PHYSIOTHERAPY RESEARCH INTERNATIONAL, Issue 2 2003
Michael Hartwick
Abstract Background and Purpose Pain during activities of daily living is a common presenting complaint of individuals with knee osteoarthritis and anterior cruciate ligament injury. Knee pain is also associated with a decrease in quality of life for people with osteoarthritis. The purpose of the present study was to examine the dose,response relationship between knee joint forces and painful symptoms, and whether the acute symptoms, were associated with individuals' quality of life. Method This was a cross-sectional cohort correlation study. Seventeen individuals with anterior cruciate ligament (ACL)-deficient knees diagnosed with ipsilateral knee osteoarthritis completed the ACL quality of life questionnaire (ACL-QOL). The subjects also rated pain associated with each of five incremental isometric knee extension tests, proportional to their body weight. Analysis of variance was used to assess the association between pain and normalized torque. Linear regression was used to assess the correlation between the ACL-QOL score and the total pain experienced during the graded test. Results A strong relationship was found between the level of perceived knee pain and the amount of isometric torque produced (Pearson's r = 0.98; p<0.001). There was a statistically significant relationship between pain during the graded isometric test and the ACL-QOL (Pearson's r = ,0.56; p = 0.016). Conclusions Since knee joint compression is a function of active isometric knee extension torque, increased painful symptoms were associated with increased compression forces at the knee joint for these subjects. The relationship between pain provocation and disease-specific quality of life provides evidence for the proposed joint provocation test for this subject population. Weakness caused by osteoarthritis (OA) may, in part, be a negative conditioning response that would need to be overcome in rehabilitation. Copyright © 2003 Whurr Publishers Ltd. [source]


Structure correlation study of four-coordinate copper(I) and (II) complexes

ACTA CRYSTALLOGRAPHICA SECTION B, Issue 3 2000
Paul R. Raithby
The geometries of four-coordinate CuI and CuII complexes in the Cambridge Structural Database (CSD) have been analysed systematically and compared using symmetry-deformation coordinates and principal component analysis. The observed stereochemistries have been rationalized in terms of the d -electron configurations, interligand repulsion and ,-bonding effects. The results confirm that the majority of four-coordinate copper(I) complexes in the CSD adopt tetrahedral geometries and deviations from tetrahedral symmetry are caused by the presence of chelating ligands or by the incorporation of copper centres into dimeric or polymeric structures. Four-coordinate copper(II) complexes generally adopt geometries close to square planar; this is particularly evident for bis(chelate) complexes where ,-bonding is important. Distortions towards tetrahedral geometries are attributable to steric interactions of bulky substituents in the bidentate ligands. [source]


Maternal mortality in Yunnan, China: recent trends and associated factors

BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 7 2007
J Li
Objective, Yunnan Province, located in southwest China, is one of the poorest province in China. The maternal mortality ratio (MMR) is about twice the national average (56.2/100 000 live births), and in remote mountainous regions, the rate is five times higher. This study aimed to examine the progress in reduction of maternal mortality in the 1990s and early 2000s and the factors associated with this reduction in Yunnan. Design, A population-based, longitudinal, ecological correlation study. Setting, A remote province of China with a proportionately large indigenous population. Population, Populations at county, prefecture and provincial level. Methods, Using maternal mortality data collected at the province, prefecture/region and county levels, trend and time series analyses and multivariate linear regression analyses were performed using SPSS (Version 13). Main outcome measure, MMR and its change over time. Results, MMR declined substantially in the 1990s at a rate of 3.0% per year. Utilisation of prenatal and obstetric care increased and was significantly correlated with the declining trend in MMR. Hospital delivery was a strong predictor of MMR, independent of social and economic development. Both low income and illiteracy were significantly associated with increased MMR. Conclusions, Declines in maternal mortality in Yunnan over the past 14 years appear to reflect health, social and economic interventions implemented in the 1990s. The association of hospital delivery with maternal mortality may be due to the effective management of severe pregnancy and birth complications. Low income and illiteracy were associated with MMR but primarily through their impact on the use of prenatal and obstetric care. [source]