1,721,002 research outputs found
APPLICATION OF MCA FOR STUDYING AS THE LIFESTYLE AND THE AIR QUALITY CAN AFFECT FORMS OF SLEEP DISORDERED BREATHING
No full textDespite an extensive research on the adverse effects of air pollution on human health, little was known about the mechanism by which air pollutants may affect sleep. Particularly for adults, it was proposed that particles influence sleep because they cause damages to the upper airways and because they have dangerous effects on the central nervous system. It was also suggested that environmental tobacco smoke exposure (active or passive) may be a cause of poor sleep and of sleep health disparities. In this study we present the application of the Multiple Correspondence Analysis (MCA) to analyze qualitative data regarding lifestyles of patients and the analysis of results obtained combining qualitative e quantitative data. In particular, Cluster Analysis (CA), and Principal Component Analysis (PCA) were used in order to investigate the potential relationships between PM10 concentrations and the occurrence of the Obstructive Sleep Apnoea Syndrome (OSAS), a particular respiratory disease consisting in a form of sleep disordered breathing. We used a database composed of polisomnography test performed on 295 patients living in Rome urban area, data about the lifestyles related to OSAS risk factors of the patients and PM10 daily concentrations measured by Air Quality Monitoring Network of Rome urban area in 11 sampling sites from 2008 to 2011
Combined effect of radiotherapy and photodynamic therapy on in vitro human prostate model
No full textHuman prostate cancer cells were evaluated for growth after photodynamic therapy, radiotherapy, and combined treatment. Indocyanine green was tested as a photosensitizer and radiosensitizer. Two human cell lines were used: PC-3 derived from prostate carcinoma, and EPN derived from normal prostate tissue. The light source used for the photoactivation experiments was a diode laser peaked at 805 nm. The light dose incident on cells was 108 J/cm(2). Ionizing radiation was produced by a linear accelerator, and the dose was 2, 4 and 6 Gy. Cytotoxicity was evaluated by measuring the colony forming ability of cells. Our results show that indocyanine green induces cell death by photoactivation, but it does not act as a radiosensitizer if used with ionizing radiation. The combined treatment of photodynamic therapy and radiotherapy produces an additive effect which does not depend on the sequence of the two treatments. Combined treatments could be more useful since they allow the reduction of the ionizing radiation dose to obtain the same effect as one obtainable by radiotherapy alone
Enhancement of antitumor drug cytotoxicity via laser photoactivation.
No full textWe investigate the efficacy of daunomycin, some imino- and amino-substituted daunomycin analogues and the disubstituted aminoanthracenedione, mitoxantrone, in photosensitizing short-term cell kill upon irradiation in the long wavelength visible range, during incubation of Fisher rat thyroid cells with the drugs. While all compounds exhibit similar cytocidal effects on our cell line, in the absence of irradiation, administering 86 J/cm2 at wavelengths either coincident or close to drug absorption peaks causes greater enhancement in cell mortality for the 4-demethoxydaunomycin analogues than either the parent drug or its 5-imino-derivative. A lower enhancement is observed with mitoxantrone. In particular, C50 doses (i.e. concentrations that would kill 50% cells) as low as approximately 10(-9) M are found for both 6- and 11-amino 4-demethoxydaunomycin, compared with the values obtained in the absence of light, which are 2.59 x 10(-4) and 0.43 x 10(-4) M, respectively. Our previous studies of the photophysical and photochemical properties of the excited states of these drugs, and ESR and spin trapping studies of photosensitized generation of singlet oxygen, which were extended in this work to include mitoxantrone, indicate that the cytocidal effects proceed via type I rather than type II mechanisms
Determination of the concentration scaling law of the scattering coefficient of water solution of Intralipid at 832 nm by comparison between collimated detection measurements and Monte Carlo simulations
No full textBackground and Objectives: Intralipid (IP) is a scatterer extensively used in the building of phantoms for Biomedical Optics measurements. Recently, deviations from the linearity have been shown for the concentration scaling law of the scattering coefficient of IP water solutions at visible
wavelengths. In this work this scaling law was determined at 832 nm.Study Design/Materials and Methods: Space resolved transmittance measurements of a laser beam at 832 nm through water solutions of IP and ink were performed and compared with the corresponding results of Monte Carlo simulations.Results: The comparison provides a quadratic dependence of mu'(S) on the volume-to-volume scatterer concentration, C-IP, in the range
of C-IP values (0.0024 < C-IP < 0.0075). These deviations from the linear behavior are related to the failure of the independent scatterer approximation.Conclusion: The quadratic dependence of mu'(S) on C-IP is in agreement with recent results obtained by other groups with different experimental techniques and is validated by a recent theoretical work
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
In vivo tumor detection in small animals by hematoporphyrin-mediated fluorescence imaging.
No full textOBJECTIVE: Noninvasive in vivo imaging of human tumors implanted in mice provides a reliable and economic tool for the investigation of tumor progression and metastasis and of the effectiveness of the antiblastic drugs on them. The purpose of this study
Laser Photosensitization of Cells By Hypericin
No full textAdministering a light dose of 90 J/cm(2) at 599 nm during incubation with hypericin to a highly differentiated normal epithelial cell line (FRTL-5), derived from Fisher rat thyroid, and to a neoplastic cell line (MPTK-6), derived from the lung metastases of a thyroid carcinoma induced in Fisher rats, produces cell kill at drug doses 1000 times lower than those necessary to cause the same mortality in the dark. The photocytocidal activity of this polycyclic quinone drag on neoplastic cells is superior to that of antitumor anthraquinone drugs, such as daunomycin and mitoxanthrone, and to the photosensitized antiviral activity previously reported for hypericin
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