1,720,957 research outputs found
Correlation between tumour antigens and malignancy in BKV-transformed hamster cells.
No full textHamster kidney cells transformed by BK virus (HKBK cells) were studied in order to correlate the membrane tumour antigens to the metastatic capability. The presence of the tumour associated surface antigen (TASA) on the surface of HKBK cells was detected by the immunofluorescence test on live cell suspensions. The metastatic ability was investigated by inoculating HKBK cells subcutaneously (s.c.) into newborn hamsters, s.c., intraperitoneally (i.p.) and in the foot pads into adult hamsters, and s.c. into adult hamsters previously immunized with surface antigens extracted from HKBK cells. The results indicate that there is a correlation between the appearance of tumour antigens on the cell surface and the metastatic ability: HKBK cells at low passage (about 30 subcultures after transformation) showed the capping of TASA in the cell membrane and low metastatic ability, whereas HKBK cells at high passage (about 130 subcultures after transformation) exhibited a diffuse appearance of TASA in the cell surface and were highly metastatic
MORPHOLOGICAL-STUDY OF INDUCED-TUMORS IN THE NUDE-MOUSE WITH TRANSFORMED CRICETUS CELLS OF BK VIRUS
No full textTransforming activity of DNA extracted from BKV-transformed hamster cells after passages in culture
No full textPrimary fetal rat fibroblasts (FRF cells) were transfected with DNA extracted from BKV-transformed hamster kidney cells at low passage after transformation (HKBKlp cells) and at high passage after transformation (HKBKhp cells). Two transformed rat cell lines were obtained, FRF-DNA-HKBKlp cells and FRF-DNA-HKBKhp cells, transformed by DNA extracted from HKBKlp cells and HKBKhp cells, respectively. They were characterized by a number of biological properties and by tumorigenicity and metastatic ability in newborn hamsters. The two transformed FRF cell lines exhibited exactly inverted properties in comparison with HKBK cells, in particular FRF-DNA-HKBKlp cells showed a low level of nuclear T antigen and a diffuse appearance of TSTA at the cell surface, whereas FRF-DNA-HKBKhp cells demonstrated a high level of T antigen and the capping of TSTA in the cell membrane. The tumorigencity and the metastatic ability were greater with FRF-DNA-HKBKlp cells, while FRF-DNA-HKBKhp cells appeared to be less tumorigenic and metastatic in newborn hamsters
Biology and natural history of prostatic cancer: necessity of early diagnostic screening.
No full text
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
