1,721,044 research outputs found
Le proprietà di LACTOBACILLUS CASEI SHIROTA
No full textTutti conoscono il significato della denominazione “batteri probiotici”, ma pochi sono a conoscenza di quando l’uomo si è reso conto dell’importanza di alcuni batteri per il mantenimento della propria salute. Più di un secolo fa, Tissier osservò che i batteri intestinali di neonati allattati al seno erano prevalentemente di forma bifida (denominati successivamente bifidobatteri) e che tali microrganismi erano totalmente assenti in bambini affetti da diarrea intestinale e che ricevevano latte artificiale [1]. Da allora, una serie molto ampia di studi ha approfondito e supportato l’associazione tra alcuni batteri intestinali e la salute dell’uomo, tanto da definire con elevato grado di sicurezza quali batteri possono essere classificati come “probiotici” in base a comprovati effetti benefici sulla salute dell’ospite [2]. Negli ultimi anni, la progressione nella ricerca è avvenuta di pari passo con la sensibilizzazione del consumatore sull’importanza della flora batterica intestinale nella salute umana, e sulla necessità di mantenere una configurazione bilanciata di tale comunità. Questa consapevolezza ha di fatto stimolato il mercato degli integratori alimentari contenenti probiotici, mirati a favorire l’equilibrio della flora intestinale, che nel solo periodo tra aprile 2016 e marzo 2017, ha avuto un valore di vendite pari a 338,2 milioni di euro solo in Italia [Fonte: Elaborazione FederSalus dati New Line Ricerche di Mercato e IRi (MAT Marzo 2017); https://microbioma.it/iniziative/mercato-dei-probiotici-in-italia/]. Tra i principali effetti benefici associati al consumo di probiotici, va sicuramente annoverato il miglioramento dei sintomi legati all’intolleranza al lattosio e la riduzione dei disturbi intestinali, quali costipazione e diarrea [3,4]. Tuttavia, oggi, l’uso dei probiotici non è più consigliato solo come trattamento coadiuvante di disturbi o malattie legati al nostro intestino, ma anche in tutta una serie di complicanze legate ad uno stato di immunocompromissione dell’ospite, come quelle associate a immunodeficienze e terapie antitumorali, in cui è importante l’effetto di immunomodulazione dei probiotici, al fine di mantenere il delicato equilibrio tra tolleranza nei confronti di batteri commensali e antagonismo verso possibili microrganismi patogeni [5,6].
Attualmente, insieme ai bifidobatteri, i lattobacilli sono i principali microrganismi utilizzati come probiotici. A questo gruppo batterico appartengono più di 200 specie e sottospecie che sono state isolate da un’ampia gamma di risorse [7]. In particolare, i lattobacilli sono abili nel fermentare una grande quantità di substrati che includono latte, carne e piante (es. yogurt, kefir, crauti, salame, etc.) [8], e rappresentano anche uno dei componenti principali della maggior parte degli integratori alimentari attualmente in commercio contenenti probiotici. Lactobacillus casei Shirota è uno dei ceppi probiotici più studiati dalla comunità scientifica e oggetto di un’ampia letteratura che evidenza l’efficacia e la sicurezza della sua somministrazione, come descritto nel paragrafo successivo
Particulate matter emission sources and meteorological parameters combine to shape the airborne bacteria communities in the Ligurian coast, Italy
Full text linkAim of the present study is to explore how the chemical composition of particulate matter (PM) and meteorological conditions combine in shaping the air microbiome in Savona (Italy), a medium-size, heavily inhabited urban settlement, hosting a wide range of industrial activities. In particular, the air microbiome and PM10 were monitored over six months in 2012. During that time, the air microbiome was highly dynamic, fluctuating between different compositional states, likely resulting from the aerosolization of different microbiomes emission sources. According to our findings, this dynamic process depends on the combination of local meteorological parameters and particle emission sources, which may affect the prevalent aerosolized microbiomes, thus representing further fundamental tools for source apportionment in a holistic approach encompassing chemical as well as microbiological pollution. In particular, we showed that, in the investigated area, industrial emissions and winds blowing from the inlands combine with an airborne microbiome which include faecal microbiomes components, suggesting multiple citizens’ exposure to both chemicals and microorganisms of faecal origin, as related to landscape exploitation and population density. In conclusion, our findings support the need to include monitoring of the air microbiome compositional structure as a relevant factor for the final assessment of local air quality
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
Body composition and human gut microbiota analysis reveals an association between Christensenellacea family and visceral adiposity
No full textAppropriate 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
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