scholarly journals Polymer-Coated Magnetite Nanoparticles for Protein Immobilization

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 248
Author(s):  
Kinga Mylkie ◽  
Pawel Nowak ◽  
Patryk Rybczynski ◽  
Marta Ziegler-Borowska

Since their discovery, magnetic nanoparticles (MNPs) have become materials with great potential, especially considering the applications of biomedical sciences. A series of works on the preparation, characterization, and application of MNPs has shown that the biological activity of such materials depends on their size, shape, core, and shell nature. Some of the most commonly used MNPs are those based on a magnetite core. On the other hand, synthetic biopolymers are used as a protective surface coating for these nanoparticles. This review describes the advances in the field of polymer-coated MNPs for protein immobilization over the past decade. General methods of MNP preparation and protein immobilization are presented. The most extensive section of this article discusses the latest work on the use of polymer-coated MNPs for the physical and chemical immobilization of three types of proteins: enzymes, antibodies, and serum proteins. Where possible, the effectiveness of the immobilization and the activity and use of the immobilized protein are reported. Finally, the information available in the peer-reviewed literature and the application perspectives for the MNP-immobilized protein systems are summarized as well.

Author(s):  
K. T. Tokuyasu

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).


Author(s):  
Prakash Rao

Image shifts in out-of-focus dark field images have been used in the past to determine, for example, epitaxial relationships in thin films. A recent extension of the use of dark field image shifts has been to out-of-focus images in conjunction with stereoviewing to produce an artificial stereo image effect. The technique, called through-focus dark field electron microscopy or 2-1/2D microscopy, basically involves obtaining two beam-tilted dark field images such that one is slightly over-focus and the other slightly under-focus, followed by examination of the two images through a conventional stereoviewer. The elevation differences so produced are usually unrelated to object positions in the thin foil and no specimen tilting is required.In order to produce this artificial stereo effect for the purpose of phase separation and identification, it is first necessary to select a region of the diffraction pattern containing more than just one discrete spot, with the objective aperture.


2010 ◽  
Vol 13 (3) ◽  
pp. 29-38
Author(s):  
Ha Bich Phan ◽  
Thach Ngoc Le

Coriandrum sativum L. belongs to the Apiaceae family, which is cultivated in Dong Nai province, in this paper its seed oil of was studied. The essential oil was extracted by hydrodistillation. We used two methods for activating of hydrodistillation: conventional heating and microwave irradiating. Its physical and chemical indexes were measured. The chemical composition of this oil was identified by GC/MS and quantified by GC/FID. Linalool (75.51-77.21 %), and geranyl acetate (15.64-12.79 %) were the main constituents of the oil which were obtained in 0,32-0.39 % yield. The biological activity of this oil was reported.


2010 ◽  
Vol 51 (1-2) ◽  
pp. 215-224
Author(s):  
Alexander Carpenter

This paper explores Arnold Schoenberg’s curious ambivalence towards Haydn. Schoenberg recognized Haydn as an important figure in the German serious music tradition, but never closely examined or clearly articulated Haydn’s influence and import on his own musical style and ethos, as he did with many other major composers. This paper argues that Schoenberg failed to explicitly recognize Haydn as a major influence because he saw Haydn as he saw himself, namely as a somewhat ungainly, paradoxical figure, with one foot in the past and one in the future. In his voluminous writings on music, Haydn is mentioned by Schoenberg far less frequently than Bach, Mozart, or Beethoven, and his music appears rarely as examples in Schoenberg’s theoretical texts. When Schoenberg does talk about Haydn’s music, he invokes — with tacit negativity — its accessibility, counterpoising it with more recondite music, such as Beethoven’s, or his own. On the other hand, Schoenberg also praises Haydn for his complex, irregular phrasing and harmonic exploration. Haydn thus appears in Schoenberg’s writings as a figure invested with ambivalence: a key member of the First Viennese triumvirate, but at the same time he is curiously phantasmal, and is accorded a peripheral place in Schoenberg’s version of the canon and his own musical genealogy.


2015 ◽  
Vol 12 (1) ◽  
pp. 3910-3918 ◽  
Author(s):  
Dr Remon M Zaki ◽  
Prof Adel M. Kamal El-Dean ◽  
Dr Nermin A Marzouk ◽  
Prof Jehan A Micky ◽  
Mrs Rasha H Ahmed

 Incorporating selenium metal bonded to the pyridine nucleus was achieved by the reaction of selenium metal with 2-chloropyridine carbonitrile 1 in the presence of sodium borohydride as reducing agent. The resulting non isolated selanyl sodium salt was subjected to react with various α-halogenated carbonyl compounds to afford the selenyl pyridine derivatives 3a-f  which compounds 3a-d underwent Thorpe-Ziegler cyclization to give 1-amino-2-substitutedselenolo[2,3-b]pyridine compounds 4a-d, while the other compounds 3e,f failed to be cyclized. Basic hydrolysis of amino selenolo[2,3-b]pyridine carboxylate 4a followed by decarboxylation furnished the corresponding amino selenolopyridine compound 6 which was used as a versatile precursor for synthesis of other heterocyclic compound 7-16. All the newly synthesized compounds were established by elemental and spectral analysis (IR, 1H NMR) in addition to mass spectra for some of them hoping these compounds afforded high biological activity.


2018 ◽  
Vol 47 (2) ◽  
Author(s):  
Kempe Ronald Hope

Countries with positive per capita real growth are characterised by positive national savings—including government savings, increases in government investment, and strong increases in private savings and investment. On the other hand, countries with negative per capita real growth tend to be characterised by declines in savings and investment. During the past several decades, Kenya’s emerging economy has undergone many changes and economic performance has been epitomised by periods of stability, decline, or unevenness. This article discusses and analyses the record of economic performance and public finance in Kenya during the period 1960‒2010, as well as policies and other factors that have influenced that record in this emerging economy. 


1999 ◽  
Vol 150 (12) ◽  
pp. 484-488 ◽  
Author(s):  
Wolf Hockenjos

Concepts of near-natural forestry are in great demand these days. Most German forest administrations and private forest enterprises attach great importance to being as «near-natural» as possible. This should allow them to make the most of biological rationalisation. The concept of near-natural forestry is widely accepted, especially by conservationists. However, it is much too early to analyse how successful near-natural forestry has been to date, and therefore to decide whether an era of genuine near-natural forest management has really begun. Despite wide-spread recognition, near-natural forestry is jeopardised by mechanised timber harvesting, and particularly by the large-timber harvester. The risk is that machines, which are currently just one element of the timber harvest will gain in importance and gradually become the decisive element. The forest would then be forced to meet the needs of machinery, not the other way round. Forests would consequently become so inhospitable that they would bear no resemblance to the sylvan image conjured up by potential visitors. This could mean taking a huge step backwards: from a near-natural forest to a forest dominated by machinery. The model of multipurpose forest management would become less viable, and the forest would become divided into areas for production, and separate areas for recreation and ecology. The consequences of technical intervention need to be carefully considered, if near-natural forestry is not to become a thing of the past.


Author(s):  
Daiva Milinkevičiūtė

The Age of Enlightenment is defined as the period when the universal ideas of progress, deism, humanism, naturalism and others were materialized and became a golden age for freemasons. It is wrong to assume that old and conservative Christian ideas were rejected. Conversely, freemasons put them into new general shapes and expressed them with the help of symbols in their daily routine. Symbols of freemasons had close ties with the past and gave them, on the one hand, a visible instrument, such as rituals and ideas to sense the transcendental, and on the other, intense gnostic aspirations. Freemasons put in a great amount of effort to improve themselves and to create their identity with the help of myths and symbols. It traces its origins to the biblical builders of King Solomon’s Temple, the posterity of the Templar Knights, and associations of the medieval craft guilds, which were also symbolical and became their link not only to each other but also to the secular world. In this work we analysed codified masonic symbols used in their rituals. The subject of our research is the universal Masonic idea and its aspects through the symbols in the daily life of the freemasons in Vilnius. Thanks to freemasons’ signets, we could find continuity, reception, and transformation of universal masonic ideas in the Lithuanian freemasonry and national characteristics of lodges. Taking everything into account, our article shows how the universal idea of freemasonry spread among Lithuanian freemasonry, and which forms and meanings it incorporated in its symbols. The objective of this research is to find a universal Masonic idea throughout their visual and oral symbols and see its impact on the daily life of the masons in Vilnius. Keywords: Freemasonry, Bible, lodge, symbols, rituals, freemasons’ signets.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 557d-557
Author(s):  
Jennifer Warr ◽  
Fenny Dane ◽  
Bob Ebel

C6 volatile compounds are known to be produced by the plant upon pathogen attack or other stress-related events. The biological activity of many of these substances is poorly understood, but some might produce signal molecules important in host–pathogen interactions. In this research we explored the possibility that lipid-derived C6 volatiles have a direct effect on bacterial plant pathogens. To this purpose we used a unique tool, a bacterium genetically engineered to bioluminesce. Light-producing genes from a fish-associated bacterium were introduced into Xanthomonas campestris pv. campestris, enabling nondestructive detection of bacteria in vitro and in the plant with special computer-assisted camera equipment. The effects of different C6 volatiles (trans-2 hexanal, trans-2 hexen-1-ol and cis-3 hexenol) on growth of bioluminescent Xanthomonas campestris were investigated. Different volatile concentrations were used. Treatment with trans-2 hexanal appeared bactericidal at low concentrations (1% and 10%), while treatments with the other volatiles were not inhibitive to bacterial growth. The implications of these results with respect to practical use of trans-2 hexanal in pathogen susceptible and resistant plants will be discussed.


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