1,721,000 research outputs found
Evidence of natural GHB presence in energy drinks: Caution in data interpretation in suspected DFSA cases
No full textGamma-hydroxybutyric acid (GHB), usually reported as rape drug in drug-facilitated sexual assaults (DFSA), is an endogenous substance in human body and is also found in many beverages. This may lead to data misinterpretation in forensic cases. Herein, we aimed to collect evidence about natural GHB presence in 13 energy drinks (ED). After a liquid–liquid extraction with acidic ethyl acetate, samples were derivatized with BSTFA 1% TMCS. Analyses were carried out by a GC–MS system in SIM mode (GHB, 233, 234, 143 and 147 m/z; GHB-d6 , 239, 240, 120 and 206 m/z). GHB was present in all the samples at very low concentrations ranging from 98 to 197 ng/mL. Thus, GHB presence in ED is not exclusively related to exogenous addition. Since the GHB levels are far lower than the minimum active dose (i.e., 0.5 g), it is not expected to induce any effect
New psychoactive substances. An actual problem or an overestimated phenomenon?
No full textIn last years, international and national Institutions have been completely focused on the new psychoactive substances (NPS) phenomenon. Many contrast policies have been planned in order to control their spread. Even scientific entities, such as our Forensic Toxicology Division, have spent time and resources for NPS identification in biological (from clinical and forensic caseworks) and non-biological (seized material) samples. Last reports show a low prevalence of NPS across the Europe and Italy, while the classical drugs are still the main cause of drug-related deaths. In particular, a worrisome datum is represented by the increasing number of deaths due to heroin. Seen these statistics, is the NPS phenomenon overestimated? Is the interest in classical drugs decreased? Were we diverted by NPS
GHB: farmaco, sostanza d’abuso e droga da stupro: diverse tipologie di uso, differenti problematiche analitico-forensi
Full text linkL’acido gamma-idrossibutirrico (GHB) è un neurotrasmettitore con effetti gaba-mimetici; si tratta di un composto
endogeno, ma notoriamente usato per le applicazioni terapeutiche come anestetico per via endovenosa,
come sedativo e per il trattamento della narcolessia. Dagli anni ‘80 è comune sostanza usata come doping, quindi
emerge come droga da “tempo libero” nei rave-party; più recentemente, i supposti effetti afrodisiaci e la reale
capacità di induzione di amnesia retrograda ne hanno indotto l’utilizzazione quale sostanza in grado di ridurre la
capacità di resistenza della vittima di uno stupro annoverandola tra le cosiddette “date rape drugs” (Drug facilitated
sexual assault, DFSA), e cioè sostanze psicoattive usate per lo stupro cosiddetto “dopo appuntamento”1. Nel
presente contributo si riporta l’approccio metodologico relativamente a due differenti scenari di interesse forense:
l’abuso del GHB con quadro di dipendenza patologica e l’uso del GHB come droga da stupro; gli Autori illustrano
le modalità di indagine per determinare il GHB nelle differenti matrici biologiche. Conclusioni: gli scenari
d’abuso qui presentati rafforzano il concetto che l’analitica tossicologica rivolta alla determinazione del GHB,
per tutte le evenienze riguardanti l’uso/abuso e le possibili implicazioni legali, deve realizzarsi secondo canoni
analitici convalidati
Enhancing the sensitivity of the LC-MS/MS detection of propofol in urine and blood by azo-coupling derivatization
No full textFatty acid ethyl esters in hair: correlation with self-reported ethanol intake in 160 subjects and influence of estroprogestin therapy.
No full textDetermination of endogenous GHB levels in chest and pubic hair
No full textEndogenous nature of GHB represents a critical issue for forensic toxicologists, especially in alleged sexual assaults. Therefore, discrimination between physiologically and additional amounts from exogenous sources of such a substance must be effective and reliable in order to avoid severe misinterpretation. This study aimed to quantify the GHB baseline concentrations in chest and pubic hairs collected from 105 healthy volunteers, non-consumers of any drugs of abuse. The final scope was to investigate if these keratin matrices could represent valid alternative to scalp hair when not available. Moreover, we also evaluated the age and gender influences on the GHB baseline levels. 25 mg of hair were incubated overnight with NaOH at 56 °C. After acidification with H2SO4, the solution was liquid-liquid extracted with ethyl acetate and a trimethylsilyl derivatization was then achieved. Analysis was performed in gas chromatography-mass spectrometry in single ion monitoring mode (m/z 233, 234, 147 for GHB; m/z 239, 240 and 147 for GHB-d6). The endogenous amount in “blank” hair was estimated by the standard addition method (0.301 for chest hair and 0.235 ng/mg for pubic hair). GHB concentration ranged from 0.205 to 1.511 ng/mg for chest hair and from 0.310 to 1.913 ng/mg for pubic hair. These values were consistent with previous studies on scalp hair and on pubic hair. Unfortunately, research on chest hair is not available in literature. T-Test and Linear Regression highlighted no statistically significant differences for the two matrices and for all age/gender sub-groups. However, further studies are required to estimate a reliable cut-off value for these keratin matrices. For the first time, we demonstrated the suitability of chest and pubic hair to detect endogenous levels of GHB
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
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