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Definizione e standard operativi per le banche degli occhi italiane: la proposta di un modello di riferimento
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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
Morphological Aspect of LASEK. Lasek & Asa History Technique Long-term Results.
No full textThe quality of the results of a photoablative
refractive surgery procedure is
determined by a number of factors.
From amongst these, two anatomo-physiological
factors play a critical role in influencing
firstly the action of the laser beam and secondly,
the repair reaction started up by the stromal-
epithelial complex, as a response to the
wound. These factors reside in the degree of
smoothness of the surface on which the laser is
applied and in the protective system of the
post-photoablation residual stroma. The connecting
link between these two aspects is the
method used for preparing the stromal bed to
be treated, which represents the first stage of
the keratorefractive operation with the laser.
There are two basic procedures for preparing
the stromal bed: the creation of an epithelialstromal
flap (LASIK technique) and the
corneal disepithelialization (PRK technique).
The LASEK technique was proposed with
the goal of combining the advantages of both
methods and of eliminating the possible risks
associated with them at the same time. It provides
for the removal of the epithelium, as an
integral epithelial flap, to be repositioned on
the treated stroma at the end of the laser treatment.
With the aim of ascertaining the efficacy
of the LASEK method, a large number of
pre-clinical and clinical studies have been conducted
to evaluate the two critical factors cited
at the beginning, i.e. the surface on which the
laser is applied and the consequent repair reaction
of the stromal-epithelial complex
Effect of hyaluronic acid-based medium upon storage and transplantation of donor corneas
No full texthttp://hdl.handle.net/20.500.11768/9684
Next-generation sequencing for the detection of microorganisms present in human donor corneal preservation medium
Full text linkObjective To detect the presence of microorganisms in the storage media of human donor corneas using next-generation sequencing method. Methods Seven samples from organ culture (OC) group (Cornea Max, Eurobio, Les Ulis, France) with one control (sterile media without any cornea) and seven samples from hypothermic storage group (Cornea Cold, Eurobio) with one control were used for this study. The corneas were placed in the respective storage media for 14 days before collecting the samples. Storage media (2 mL) from each sample were collected in RNAase-free tubes and shipped for ribosomal RNA sequencing of 16 S and 18 S. Simultaneously, another 1 mL of media sample was used for conventional diagnostic method (CDM) using Bactec instruments. Results In both, OC and hypothermic storage and control samples, the most abundant genera were Pseudomonas, Comamonas, Stenotrophomonas, Alcanivorax, Brevundimonas and Nitrobacter. Acidovorax, Acetobacter and Hydrogenophilus were detected mostly in the hypothermic storage group. The most abundant fungal pathogen detected belonged to the genus Malassezia, which was found in both the storage conditions. CDM was negative for microorganisms in all the samples. Conclusion Metagenomics provides full taxonomic profiling of the detected genomic material of the organisms and thus has the potential to deliver a much wider microbiological diagnostic approach than CDM. The costs and turn-around time need to be reduced, and; the detection of viable organisms would help this technology to be introduced into routine clinical practice
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
Bacterial contamination of human organ-cultured corneas
No full textPurpose: This study was designed to define the risk of contamination of human corneas preserved by the organ-culture method.
Methods: We examined the microbial contaminations in 3,100 corneoscleral rims cultivated in our eye bank. Microbiologic tests were performed in the preservation medium 5 days after the beginning of cornea cultures and in the last day of culture (21.5 ± 8.1 days), when the corneas were transferred to the deswelling medium. In 1,029 corneas a microbiologic test also was performed 1 day after the beginning of deswelling procedure.
Results: We found 206 microbial contaminations (6.65% of total) after 5 days and 17 (0.55%) at the end of the preservation period. The total number of contaminated samples during the cornea culture was 223 corresponding to 7.2% of the samples (95% confidence interval, 6.3-8.1). The 1,029 tests performed during the deswelling step disclosed 26 contaminated cornea cultures despite apparent sterility of the medium (2.5%; 95% confidence interval, 1.5-3.5).
Conclusions: The observation of microbial contaminations in a time close to the transplant (i.e., at the end of the preservation period and in the deswelling step) showed that a fast microbial tests during the deswelling procedure may prevent the grafting of a contaminated cornea. The appearance of bacteria in the deswelling medium despite a negative culture medium suggests that bacteria penetrate the corneal tissues during the culture to be subsequently extruded when the internal fluids move outward
Hyaluronate as a deturgescence agent during the transport phase of corneal storage by organ culture
No full texthttp://hdl.handle.net/20.500.11768/9683
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