139 research outputs found

    Self-Assembled Short Peptide Nanostructures: ‘’Dipeptides’’

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    Dipeptides are short peptide molecules formed by the peptide bond between two amino acids, and they play significant roles in various biological processes (such as protein synthesis, nutrient absorption, cellular signaling, immune response). Short peptides have a prominent place in the design of self-assembling materials. In particular, dipeptides have gained considerable attention in the field of biotechnology as a type of self-organizing nanostructure due to their low cost, simplicity of synthesis, biocompatibility, and tunability of functionality. However, there is limited knowledge about peptide and protein-based nanostructures in the literature. Therefore, more information is needed on dipeptide nanostructures, especially in terms of their potential applications for biomedical purposes. This review focuses on dipeptide nanostructures, particularly their potential uses in biomedical applications, and provides a broader perspective on the advantages, challenges, synthesis, interactions, and applications of these nanostructures

    Effect of Co and Fe on the inverse magnetocaloric properties of Ni-Mn-Sn

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    At certain compositions Ni-Mn-XX Heusler alloys (XX: group IIIA-VA elements) undergo martensitic transformations, and many of them exhibit inverse magnetocaloric effects. In alloys where XX is Sn, the isothermal entropy change is largest among the Heusler alloys, particularly in Ni50_{50}Mn37_{37}Sn13_{13} where it reaches a value of 20 Jkg1^{-1}K1^{-1} for a field of 5T. We substitute Ni with Fe and Co in this alloy, each in amounts of 1 at% and 3 at% to perturb the electronic concentration and examine the resulting changes in the magnetocaloric properties. Increasing both Fe and Co concentrations causes the martensitic transition temperature to decrease, whereby the substitution by Co at both compositions or substituting 1 at% Fe leads to a decrease in the magnetocaloric effect. On the other hand, the magnetocaloric effect in the alloy with 3 at% Fe leads to an increase in the value of the entropy change to about 30 Jkg1^{-1}K1^{-1} at 5T.Comment: 5 pages, 7 figures. Accepted for publication in the Journal of Applied Physic

    Inhibition of bacterial adhesion by epigallocatechin gallate attached polymeric membranes

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    Microbial adhesion and formation of biofilms cause a serious problem in several areas including but not limited to food spoilage, industrial corrosion and nosocomial infections. These microbial biofilms pose a serious threat to human health since microbial communities in the biofilm matrix are protected with exopolymeric substances and difficult to eradicate with antibiotics. Hence, the prevention of microbial adhesion followed by biofilm formation is one of the promising strategies to prevent these consequences. The attachment of antimicrobial agents, coatings of nanomaterials and synthesis of hybrid materials are widely used approach to develop surfaces having potential to hinder bacterial adhesion and biofilm formation. In this study, epigallocatechin gallate (EGCG) is attached on p(HEMA-co-GMA) membranes to prevent the bacterial colonization. The attachment of EGCG to membranes was proved by Fourier-transform infrared spectroscopy (FT-IR). The synthesized membrane showed porous structure (SEM), and desirable swelling degree, which are ideal when it comes to the application in biotechnology and biomedicine. Furthermore, EGCG attached membrane showed significant potential to prevent the microbial colonization on the surface. The obtained results suggest that EGCG attached polymer could be used as an alternative approach to prevent the microbial colonization on the biomedical surfaces, food processing equipment as well as development of microbial resistant food packaging systems

    Magnetization easy-axis in martensitic Heusler alloys estimated by strain measurements under magnetic-field

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    We study the temperature dependence of strain under constant magnetic-fields in Ni-Mn based ferromagnetic Heusler alloys in the form Ni-Mn-XX (XX: Ga, In, Sn, Sb) which undergo a martensitic transformation. We discuss the influence of the applied magnetic-field on the nucleation of ferromagnetic martensite and extract information on the easy-axis of magnetization in the martensitic state.Comment: 3 pages, 3 figures. Accepted for publication in Applied Physics Letter

    Magnetic superelasticity and inverse magnetocaloric effect in Ni-Mn-In

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    Applying a magnetic field to a ferromagnetic Ni50_{50}Mn34_{34}In16_{16} alloy in the martensitic state induces a structural phase transition to the austenitic state. This is accompanied by a strain which recovers on removing the magnetic field giving the system a magnetically superelastic character. A further property of this alloy is that it also shows the inverse magnetocaloric effect. The magnetic superelasticity and the inverse magnetocaloric effect in Ni-Mn-In and their association with the first order structural transition is studied by magnetization, strain, and neutron diffraction studies under magnetic field.Comment: 6 pages, 8 figures. Published in the Physical Review

    Examining to see elite sight-disabled athletes according to the dimensions of the scale of motivation in sport

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    Made the purpose of this study is to examine to see disabled athletes according to the dimensions of the scale of motivation in sport. The study group is comprised of 168 visually impaired athletes in total, including 51 females and 117 males, identified by the targeted sampling method, between the ages of 15-25, who do sports at elite level. The Sport Motivation Scale (SMS) was developed by Pelletier (1995) basing on the Theory of Self Determination by Deci and Ryan (1985). The purpose of SMS is to determine the level of "internal motivation, external motivation and nonmotivation” of the person in the sports environment and to identify the source of motivation of the person (Kazak, 2004). Validity and reliability of the scale for Turkish athletes was studied by Kazak (2004).  In conclusion, this study has demonstrated that to know and succeed and to experience stimuli and identification subdimensions are effective in sports attendance of visually impaired athletes engaged in sports at elite level. Moreover, it has been demonstrated that age, education level and sports branch variables have an impact on tendency for sports. It can be concluded that compared to older athletes, younger athletes have low tendency for sports because of anxiety and embarrassment and are not conscious about why they do sports. It has been concluded that athletes of weight lifting and judo, which have contribution to physical development at the top level, believe the nature of their sports branch contributes more to their physical development and their strength is acknowledged and appreciated by other people.// Annotate Highligh

    Magnetic superelasticity and inverse magnetocaloric effect in Ni-Mn-In

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    Applying a magnetic field to a ferromagnetic Ni50_{50}Mn34_{34}In16_{16} alloy in the martensitic state induces a structural phase transition to the austenitic state. This is accompanied by a strain which recovers on removing the magnetic field giving the system a magnetically superelastic character. A further property of this alloy is that it also shows the inverse magnetocaloric effect. The magnetic superelasticity and the inverse magnetocaloric effect in Ni-Mn-In and their association with the first order structural transition is studied by magnetization, strain, and neutron diffraction studies under magnetic field.Comment: 6 pages, 8 figures. Published in the Physical Review
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