scholarly journals Microencapsulation of Riboflavin (Vitamine B2) using Alginate and Chitosan : Effect of Surfactant Span 80 upon Microcapsule Diameter

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
YC. Danarto ◽  
Rochmadi Rochmadi ◽  
Budhijanto Budhijanto
Keyword(s):  
Sodium Alginate ◽  
Environmental Influences ◽  
Reducing Agents ◽  
Vitamin B2 ◽  
Human Metabolism ◽  
Paraffin Oil ◽  
Highly Sensitive ◽  
Span 80

<p>Riboflavin (vitamin B2) plays an important role in the growth and maintenance of human metabolism. Riboflavin is the highly sensitive and unstable to environmental influences such as light, reducing agents and pH. Riboflavin is protected by forming it into microcapsules with sodium alginate as a matrix and coated with chitosan reinforced with glutraldehid crosslinking. This study aims to study the process of microencapsulation of riboflavin with sodium alginate and chitosan and is emphasized to study the effect surfactant span 80 upon the size of the microcapsules formed. Based on microcapsule size and its distribution,  it  can  be  concluded  that  more  span  80  added  to  paraffin  oil  will  reduce  the  size  of microcapsule that is formed</p>

Highly sensitive adolescent benefits in positive school transitions: Evidence for vantage sensitivity in Japanese high-schoolers

2020 ◽  
Author(s):  
Shuhei Iimura
Keyword(s):  
High School ◽  
Statistical Power ◽  
Environmental Influences ◽  
Differential Susceptibility ◽  
School Transition ◽  
Well Being ◽  
Crossover Point ◽  
Japanese Adolescents ◽  
Highly Sensitive

Some researchers indicate that the transition to high school deflects adolescent developmental trajectories. Others assert it provides a new possibility for the promotion of adolescents’ socioemotional well-being. One critical view missing in such claims is that individual variabilities interact with environmental influences. We employed the framework of Differential Susceptibility Theory, which postulates that individual susceptibilities moderate external influences for better and for worse. In order to clarify the mechanism of adolescents’ differential adjustments, this paper investigated the role of sensory-processing sensitivity using the Japanese version of Highly Sensitive Child Scale for Adolescence (J-HSCS), and tested whether the diathesis-stress model or the differential susceptibility model best describes students’ socioemotional adjustment across their high school transition. The current paper used the two-wave data collected from Japanese adolescents aged from 14 to 15 years (n = 412, 50% girls). In Study 1, we investigated the replicability of psychometric properties of J-HSCS. The results supported previous findings, indicating its validity for the bifactor model. In Study 2, we utilized confirmatory competitive model testing, which maximizes statistical power by parameterizing the crossover point to allow a direct comparison of alternative models. The results indicated that neither the diathesis-stress nor the differential susceptibility models fitted the data. Rather, a strong vantage sensitivity model was revealed, suggesting that highly susceptible adolescents disproportionately benefitted from a positive school transition over their counterparts. This finding signified the role of adolescents’ sensitivity to environmental influences and the importance of considering its moderation under person x environment interactions.

scholarly journals The technology of the selective precipitation of arsenic from solutions for its detection and isolation

2021 ◽  
Author(s):  
Avak Avakyan
Keyword(s):  
Water Solution ◽  
Reducing Agents ◽  
Selective Precipitation ◽  
Qualitative Reaction ◽  
Highly Sensitive ◽  
Amorphous Precipitate

This is a technology of the selective precipitation of (AsO4)3− from solutions as the Fe3+ hydroxoarsenate using the FeCl3, NaHCO3 and CH3CO2H. This can be used as a qualitative reaction for arsenic. The dissolving of the Fe3+ and Ag+ arsenates in CH3CO2H in the presence of the CH3CO2Na is discovered. The Fe3+ acetate is stable in water solution without other reagents (it was discovered); and it is stable in CH3CO2H solutions. The arsenic can be isolated using the reactions: Fe3+ hydroxoarsenate + reducing agents, example: Ca(H2PO2)2, as the dark amorphous precipitate (like soot). Then it can be sublimated. This is a safe easy reliable highly sensitive alternative to the Marsh test.

Fabrication of highly sensitive ethanol sensor based on doped nanostructure materials using tiny chips

RSC Advances ◽  
2015 ◽  
Vol 5 (78) ◽  
pp. 63252-63263 ◽  
Author(s):  
Mohammed M. Rahman ◽  
Abdullah M. Asiri
Keyword(s):  
Chemical Process ◽  
Reducing Agents ◽  
Ethanol Sensor ◽  
Medium Ph ◽  
High Ph ◽  
Nanostructure Materials ◽  
Highly Sensitive ◽  
Wet Chemical

Doped CuO–Fe2O3 nanocubes (NCs) are prepared via a facile wet-chemical process using active reactant precursors with reducing agents in high pH medium (pH > 10).

Gold Nanoparticle Enlargement Coupled with Fluorescence Decrease for Highly Sensitive Detection of Analytes

2011 ◽  
Vol 1301 ◽  
Author(s):  
Seong Yoon Lim ◽  
Jae Hong Kim ◽  
Joon Seok Lee ◽  
Chan Beum Park
Keyword(s):  
Gold Nanoparticles ◽  
Enzymatic Reaction ◽  
Optical Biosensor ◽  
Reducing Agents ◽  
Sensitive Detection ◽  
Detection Methods ◽  
Fluorescent Substrate ◽  
Reaction Solution ◽  
Highly Sensitive ◽  
Highly Sensitive Detection

ABSTRACTWe present a versatile and facile route for highly sensitive detection of analytes through coupling the enlargement of gold nanoparticles (Au NPs) with fluorescence decrease. The fluorescence intensity of dye molecules (e.g., fluorescein or rhodamine B) significantly decreased with the increasing concentration of reducing agents, such as hydrogen peroxide and hydroquinone. The sensitivity for the detection of reducing agents was much higher than other detection methods based on the absorbance measurement of enlarged gold nanoparticles or quantum dot-enzyme hybridization. We could successfully detect acetylthiocholine with the detection limit of several nM orders, using an enzymatic reaction by acetylcholinesterase, a key route for the detection of toxic organophosphate compounds. The fluorescence decreasing approach described in this work requires only a simple addition of fluorescence dye to the reaction solution without any chemical modification. The strategy of fluorescence decrease coupled with nanoparticle growth will be applied on the fluorescent substrate to develop detection templates for highly sensitive optical biosensor.

scholarly journals People Differ in their Sensitivity to the Environment: An Integrated Theory and Empirical Evidence

2020 ◽  
Author(s):  
Michael Pluess ◽  
Francesca Lionetti ◽  
Elaine N. Aron ◽  
Arthur Aron
Keyword(s):  
Empirical Evidence ◽  
Big Five ◽  
Environmental Influences ◽  
Experimental Studies ◽  
Big Five Personality ◽  
Personality Profile ◽  
Total N ◽  
Integrated Theory ◽  
Highly Sensitive ◽  
Positive Experiences

People differ in their sensitivity to similar experiences with some being generally more and some less sensitive. Several theories have been developed over the years to describe such differences in Environmental Sensitivity and a growing number of studies provide empirical evidence that some people are indeed more affected than others by environmental influences. Sensitivity has been associated with temperament traits in children as well as a number of biological factors. In this paper, we provide new experimental evidence that self-reported sensitivity predicts differences in the response to negative as well as positive experiences, after introducing a short sensitivity questionnaire for adults, building on the original Highly Sensitive Person scale (Aron &amp; Aron, 1997), and investigating its psychometric properties as well as associations with the Big Five personality traits. Results across the five individual studies (total N = 1,140) suggest that individual differences in sensitivity to the environment can be assessed with the newly developed measure (HSP-12), validated by two experimental studies according to which the scale predicts heightened reactivity to both negative and positive experiences. Furthermore, sensitivity reflects a continuous spectrum from low to high along which people fall into three distinct sensitivity groups (low, medium, and high). Finally, sensitivity was found to fit a specific personality profile characterised by both high Neuroticism and high Openness to Experiences. We conclude that adults differ substantially in their sensitivity to environmental influences and that such differences can be measured reliably with a short and easily applicable sensitivity questionnaire.

scholarly journals Interfacial Dilational Viscoelasticity of Adsorption Layers at the Hydrocarbon/Water Interface: The Fractional Maxwell Model

2019 ◽  
Vol 3 (4) ◽  
pp. 66 ◽  
Author(s):  
Giuseppe Loglio ◽  
Volodymyr I. Kovalchuk ◽  
Alexey G. Bykov ◽  
Michele Ferrari ◽  
Jürgen Krägel ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Maxwell Model ◽  
Water Interface ◽  
Paraffin Oil ◽  
Viscoelastic Modulus ◽  
Dilational Viscoelasticity ◽  
Span 80 ◽  
Fractional Maxwell Model ◽  
Adsorption Layers ◽  
Solution Matrix

In this communication, the single element version of the fractional Maxwell model (single-FMM or Scott–Blair model) is adopted to quantify the observed behavior of the linear interfacial dilational viscoelasticity. This mathematical tool is applied to the results obtained by capillary pressure experiments under low-gravity conditions aboard the International Space Station, for adsorption layers at the hydrocarbon/water interface. Two specific experimental sets of steady-state harmonic oscillations of interfacial area are reported, respectively: a drop of pure water into a Span-80 surfactant/paraffin-oil matrix and a pure n-hexane drop into a C13DMPO/TTAB mixed surfactants/aqueous-solution matrix. The fractional constitutive single-FMM is demonstrated to embrace the standard Maxwell model (MM) and the Lucassen–van-den-Tempel model (L–vdT), as particular cases. The single-FMM adequately fits the Span-80/paraffin-oil observed results, correctly predicting the frequency dependence of the complex viscoelastic modulus and the inherent phase-shift angle. In contrast, the single-FMM appears as a scarcely adequate tool to fit the observed behavior of the mixed-adsorption surfactants for the C13DMPO/TTAB/aqueous solution matrix (despite the single-FMM satisfactorily comparing to the phenomenology of the sole complex viscoelastic modulus). Further speculations are envisaged in order to devise combined FMM as rational guidance to interpret the properties and the interfacial structure of complex mixed surfactant adsorption systems.

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