Search results for "Comet"

Separation of Nanoparticles by Gel Electrophoresis According to Size and Shape

2007

We demonstrate the separation of gold and silver nanoparticles according to their size and shape by agarose gel electrophoresis after coating them with a charged polymer layer. The separation is monitored optically using the size- and shape-dependent plasmon resonance of noble metal particles and confirmed by transmission electron microscopy (TEM). Electrophoretic mobilities are quantitatively explained by a model based on the Henry formula, providing a theoretical framework for predicting gel mobilities of polymer coated nanoparticles.

The assessment of susceptibility to emotional contagion: A contribution to the Italian adaptation of the “Emotional Contagion Scale”

2013

The Emotional Contagion Scale (ECS; Doherty, 1997) is a self-report instrument assessing susceptibility to emotional contagion. The study was aimed at examining its dimensionality, reliability, and validity in the Italian context. It was completed by 541 young adults (45% men) in Study 1 and 649 young adults (40% men) in Study 2. The results of a series of confirmatory factor analyses showed that a bi-factor model, with one general factor and four specific factors was supported. The general and specific factors resulted differently related to self-other differentiation, empathy, emotional fragility, masculinity, and femininity. Notwithstanding, the results posited some questions about the E…

Type D Personality and Alexithymia: Common Characteristics of Two Different Constructs. Implications for Research and Clinical Practice

2018

In the last few decades, particular attention has been paid to the role of personality specific traits that can affect the loss of health, i.e., Type D personality and Alexithymia. They have been conceptualized in a different period, this means that they are different both for their theoretical positions and their empirical studies. Some authors have speculated that there is a potential conceptual overlap between Type D personality and alexithymia constructs but there is a shortcoming in the literature. The aim of the study was to examine the potential overlap between the constructs of type D personality and alexithymia, replicating previous two studies, to extend these findings to Italian …

Interaction through social media: Development and validation of a social network site self-efficacy scale (SNS-SES)

2023

Today, more than ever before, awareness of our ability to interact with others through and use social network sites (SNSs) is of fundamental importance, in light of the fact that we are connected to the Web 24 h a day, 7 days a week. Studies of social media in recent decades have shown that self-efficacy is one of the key variables affecting individual online behavior. The general aim of the studies presented here was to develop and validate a new self-report scale measuring self-efficacy in SNS use (an SNS self-efficacy scale, or SNS-SES). Across two studies, a total of 1295 Italian adolescents and adults (ages 15 to 89; M = 38.21, SD = 15.6) participated. The SNS-SES consists of 24 items …

The Multigroup Ethnic Identity Measure – Revised (MEIM-R): Psychometric evaluation with adolescents from diverse ethnocultural groups in Italy

2017

The Multigroup Ethnic Identity Measure – Revised (MEIM-R) is an extensively used questionnaire assessing ethnic identity. However, studies on its measurement characteristics in the European context are lacking. The current study addressed this gap by investigating the MEIM-R psychometric proprieties across multiple ethnocultural groups in Italy. Participants were 1445 adolescents (13–18 years) of Italian, East European, and North African origin. Results showed that the MEIM-R has good internal consistency. Multigroup confirmatory factor analyses revealed configural and metric invariance, i.e., an equal, correlated two-factor structure (ethnic identity exploration and commitment) and equal f…

Relationships Between Ethnic Identity, Ethnic Attitudes, and Acculturative Stress in Tunisian Individuals in Early and Middle Adolescence

2016

Framed from an integrative approach, the current article examined the associations between ethnic identity exploration (EIE), ethnic identity commitment (EIC), and acculturative stress by investigating the mediating role of ethnic attitudes (i.e., in-group favoritism and out-group derogation) in these relationships. Additionally, the moderating role of age was analyzed. A multiple-group path analysis was performed on data collected from 256 Tunisians in early and 248 in middle adolescence living in Italy, which is an interesting and understudied immigrant group characterized by similarities and differences with the host population. In younger adolescents, EIE and EIC were indirectly and po…

1985

Viscosities were measured as a function of pressure and temperature with solutions of PVC 75 000 in cyclohexanone (CHO) and polymer contents ranging from 0,6 to 12 wt.-%, by means of a Searle-type (≥3 wt.-%) and a rolling-ball viscometer (<3 wt.-%). Furthermore, the influence of molecular weight was determined with solutions of 8 wt.-% of PVC 20 000, PVC 37 000 and PVC 100 000. (The numbers in the codes of the PVC specimens are their approximate molecular weights.) For all concentrations and molecular weights, the viscosity increases in a more or less exponential manner with increasing pressure. The ratio f1000 of the viscosity of the solution at 1 000 and 1 bar can be varied by the change …

Extension of GPC Techniques

1971

Abstract Most of the common GPC gels exhibit pore sizes which are too small to separate very extended molecules, e.g., native cellulose in solution. Several gel types were tested with vinyl polymers of molecular weights up to 107 and with cellulose nitrate. Large pore size Styragel with acetone as solvent proved to be the most favorable gel system yielding effective separations for polymers with coil diameters in solution up to 4000 A. The evaluation of GPC runs usually requires a separate calibration procedure. We attempted to determine the molecular weight of the eluate directly as it leaves the column. This is done by a special automatic viscometer that allows measurement of the viscosit…

The space age and the origin of space research

2001

The exploration of space is one of the greatest achievements of the twentieth century. In the ideal photo album of this century one could hardly avoid including such pictures as our blue planet seen from space and the human footprint on the Moon’s surface; the close-up images of a comet’s nucleus and the rough landscape of Mars; the floating of astronauts in the black vacuum around a space station and the rings of Saturn photographed from an approaching spacecraft.

Genotoxic and endocrine activities of bis(hydroxyphenyl)methane (bisphenol F) and its derivatives in the HepG2 cell line

2008

International audience; Human can be exposed to bis(hydroxyphenyl)methane (bisphenol F or BPF) and its derivatives as environment and food's contaminants. This study was investigated to identify and to compare toxic potency of BPF, BFDGE, and two of BPF metabolites using in vitro methods. BPF did not induce any genic mutation in bacteria when the Ames test was performed according to the OECD guideline. In contrast, using Human cell lines and Comet assay, we demonstrated that BPF and Bisphenol F Diglycidyl Ether (BFDGE) were effective on HepG2 cell DNA fragmentation at non-cytotoxic concentrations. DHB was also positive but at higher concentrations, near its limit of solubility. Neither BPF,…