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Biomedical subjects

M Anghel

Publications and source records attributed to M Anghel.

At least 19 recordsLinked to original sources
PubMed2003

Estimation of entropies and dimensions by nonlinear symbolic time series analysis.

Symbolic nonlinear time series analysis methods have the potential for analyzing nonlinear data efficiently with low sensitivity to noise. In symbolic nonlinear time series analysis a time series for a fixed delay is partitioned into a small number (called the alphabet size) of cells labeled by symbols, creating a symbolic time series. Symbolic methods involve computing the statistics of words made from the symbolic time series. Specifically, the Shannon entropy of the distribution of possible words for a range of word lengths is computed. The rate of increase of the entropy with word length is the metric (Kolmogorov-Sinai) entropy. Methods of computing the metric entropy for flows as well as for maps are shown. A method of computing the information dimension appropriate to symbolic analysis is proposed. In terms of this formulation, the information dimension is determined by the scaling of entropy as alphabet size is modestly increased, using the information obtained from large word length. We discuss the role of sampling time and the issue of using these methods when there may be no generating partition.

Journal Article↗
PubMed2002

Precursory dynamics in threshold systems.

A precursory dynamics, motivated by the analysis of recent experiments on solid-on-solid friction, is introduced in a continuous cellular automaton that mimics the physics of earthquake source processes. The resulting system of equations for the interevent cycle can be decoupled and yields an analytical solution in the mean-field limit, exhibiting a smoothing effect of the dynamics on the stress field. Simulation results show the resulting departure from scaling at the large-event end of the frequency distribution, and support claims that the field leakage may parametrize the superposition of scaling and characteristic regimes observed in real earthquake faults.

Journal Article↗
PubMed2000

Clusters and fluctuations at mean-field critical points and spinodals

We show that the structure of the fluctuations close to spinodals and mean-field critical points is qualitatively different from the structure close to non-mean-field critical points. This difference has important implications for many areas including the formation of glasses in supercooled liquids. In particular, the divergence of the measured static structure function in near-mean-field systems close to the glass transition is suppressed relative to the mean-field prediction in systems for which a spatial symmetry is broken.

Journal Article↗
PubMedDate not supplied

Asian Indian women: knowledge, attitudes and behaviors toward breast cancer early detection.

Education programs have been developed to promote adherence to recommended breast cancer screening guidelines. Few studies have assessed the degree to which ethnic subgroups are perceiving and acting on the proffered information. Such assessment is vital to the creation of efficient public health interventions. This paper describes the reported breast cancer knowledge, attitudes, and screening behaviors of 194 American Asian Indian women. While monthly breast self exam adherence was low, only 40.7%, 61.3% of women 40 and older, and 70% of women 50 and older, reported having had a mammogram within the past 12 months. These rates for annual mammography screening are high relative to many other ethnic groups. While the results are encouraging, the respondents may not be representative of all Asian Indian women. The majority of these women reported that their breast cancer knowledge is inadequate. They were willing to be called upon to share with others any knowledge they gained. There is a clear opportunity for public health nurses to provide Asian Indian women with a more comprehensive understanding of breast health and disease. Those women can then share their health knowledge with other women within their ethnic group.

Adult↗
PubMedDate not supplied

Shift toward T lymphocytes with Th1 and Tc1 cytokine-secterion profile in the joints of patients with osteoarthritis.

Osteoarthritis (OA), although a heterogeneous disease, is generally believed by rheumatologists to be primarily a disease generated by biomechanical alterations. In order to determine the role of T cells, the pattern of T lymphocyte cytokines and to characterize the mononuclear cells from both peripheral blood (PB) and synovial fluid (SF) from patients with OA flow cytometry with a panel of monoclonal antibodies recognising CD4, CD8 and intracellular cytokines (IL2, IL4, IL10, gamma-IFN) was employed. The coexpression of CD4 and CD8 markers only on the SF T cells surface after in vitro stimulation by phorbol-miristate acetate and ionomicine, but not on PBL or in vitro unstimulated SFL was noted. The intracellular IFN-gamma was detected in enhanced levels in both CD4+ and CD8+ SF T cells, while the IL2 contents was not different in PB and SF samples. The Th2/Tc2 cytokines (IL4 and IL10) were detected in low amounts in both PBL and SFL. This study shows the role of some T cell populations and cytokines in the generation of joint destruction in osteoarthritis.

Aged↗
PubMedDate not supplied

The migratory and phagocytic activity of polymorphonuclear leukocytes in rheumatoid arthritis and osteoarthritis patients.

Polymorphonuclear neutrophils (PMN) play a central role in the elimination of most extracellular pathogenic microorganisms and any impairment of their functions therefore predisposes to defect immune defence. We investigated the migratory and phagocytic functions of the PMNs isolated from peripheral blood and synovial fluid of patients with rheumatoid arthritis (RA) and osteoarthritis (OA). The results suggest that in RA the number and the migratory but not phagocytic capacity of synovial fluid (SF) neutrophils were enhanced, while in OA they were significantly decreased in synovial fluid cells comparatively with peripheral blood (PB). The migratory function of both PB and SF cells from RA patients was increased comparatively with that of the cells from OA patients. We found the different abnormal functions in synovial fluid neutrophils from RA and OA patients. These results may help to elucidate the underlying mechanism which leads to severe joint destruction and different susceptibility to infectious diseases in patients with rheumatic disorders.

Arthritis, Rheumatoid↗
PubMedDate not supplied

[Post-traumatic petroso-nasal cerebrospinal fluid fistula].

The authors present five cases of posttraumatic petronosal fistulas. The stress the rarity of these cases, their anatomo-pathological aspects, the pathophysiological consequences of the osteo-meningeal fissure and the necessity of the neurosurgical treatment.

Adolescent↗
PubMedDate not supplied

[Importance of apical instrumentation limit in the endodontic technique].

An improved knowledge of anatomy and psysiology of the apical radicular region has made mandatory a better classical endodontic technique concerning the apical limit of instrumentation, and has stressed the importance of a precise determination of the cemento-dentinal junction as the apical limit of canal obturation. On the basis of these orientations a clinical and radiographic study was carried out on 120 teeth extracted form humans, in which the frequency was determined of the excentric position of the cement conus with regard to the apex, and the distance between the cemento-dentinal junction and the apex. In 45 teeth in situ, with pulpar inflammation, gangrene and apical parodontitis a clinical and radiological appraisal was done of the cemento-dentinal junction, and evolution was followed after canal obturation.

Dental Pulp Cavity↗