A new approach to high resolution, high contrast electron microscopy of macromolecular block copolymer assemblies

Determining the structure of macromolecular samples is vital for understanding and adapting their function. Transmission electron microscopy (TEM) is widely used to achieve this, but, owing to the weak electron scattering cross-section of carbon, TEM images of macromolecular samples are generally low contrast and low resolution. Here we implement a fast and practically simple routine to achieve high-contrast imaging of macromolecular samples using exit wave reconstruction (EWR), revealing a new level of structural detail. This is only possible using ultra-low contrast supports such as the graphene oxide (GO) used here and as such represents a novel application of these substrates. We apply EWR on GO membranes to study self-assembled block copolymer structures, distinguishing not only the general morphology or nanostructure, but also evidence for the substructure (i.e. the polymer chains) which gives insight into their formation mechanisms and functional properties

General Model for Adequate Cloud Service Selection using Decision Making Methods

Cloud Computing (CC) is a technology that surely brings innovations in today’s business world, more and more companies around the world are widely incorporating this technology into their businesses. From a technical, as well as organizational point of view transferring enterprise IT to the Cloud is a complex task. Various factors have to be taken into consideration in order to make a right choice when moving IT services to the Cloud. The goal of this paper is to identify and to discuss in detail all factors that influence organization’s decision to adopt Cloud. General model for Cloud adoption, introduced in Pantelic et al. [13]a, consists of the key factors driving the organizational benefits when moving to the Cloud. The purpose of the model is to support decision makers in evaluating the benefits, risks and costs of using Cloud Computing. In this paper the general model is extended with two new aggregation methods for harmonization of alternatives rankings in a group decision process. We present the results of two new methods using the method results from previous research [13], as rank inputs, into an aggregate (group) preference. The idea is to find consensus ranking that minimizes disagreement among previous methods results. There were no strong differences between the results of performed methods. The results have shown that Software as a service model and Storage as a service model dominated according to not just arithmetic-mean method, but also to geometric-mean method

Efficient production of highly purified Late Embryogenesis Abundant (LEA) protein from Arabidopsis thaliana by recombinant DNA technology

Late embryogenesis abundant (LEA) proteins are induced in cellular dehydration, such as freezing, drought, or desiccation. They can be involved in antioxidative defense, ion sequestration, and structural stabilization of both membranes and enzymes during freezing or drying, while by forming intracellular proteinaceous condensates they increase structural integrity and intracellular viscosity of cells during desiccation 1. The genome of the model plant Arabidopsis thaliana contains 51 genes encoding LEA proteins2. The majority of these LEA proteins (35%) belongs to Pfam LEA_4 (PF02987) family. In silico analysis suggested that these proteins are highly hydrophilic proteins with significant intrinsically disordered protein (IDP) properties. In order to evaluate structural properties and possible functions of LEA_4 protein family under different water content, a representative AtLEA25 protein (At2g42560, 635 aa), naturally located in the cytoplasm of seeds3 was obtained in Escherichia coli by recombinant DNA technology. Although this technology has been traditionally used to over-express and purify various globular proteins, numerous reports have shown that the IDPs, due to their structural plasicity are naturally highly susceptible to proteolytic cleavage. To conduct structural and functional studies we developed a robust method to produce highly purified (>95% pure) AtLEA25 with no detectable amount of protein breakdown products.Abstract: Serbian Biochemical Society, 10th Conference, Kragujevac, Serbia, 24.09.202

Ad Astra Academy: Using Space Exploration to Promote Student Learning and Motivation in the City of God, Rio de Janeiro, Brazil

Motivation is a primary determinant of a student&rsquo;s academic success, but in many under-resourced educational contexts around the world, opportunities to develop motivation are lacking. In the City of God neighborhood of Rio de Janeiro, Brazil, we (a group of scientists and science educators) enacted brief, interactive interventions targeting teenage students at risk of dropping out of school. Students participated in an immersive 5-day program, followed by a six-month break, before completing the second, 3-day program. Participants learned how to use the scientific method in real-world settings to generate new knowledge. In order to consolidate these knowledge gains and bolster the program&rsquo;s inspirational power, capstone projects empowered participants to speak with NASA mission managers and, in some cases, acquire never-before-seen images of Mars. While longitudinal study and a more robust sample size are required to bolster conclusions about the efficacy of our approach, initial results suggest that Ad Astra programs significantly enhance self-efficacy and science-oriented career ambitions.</p

Disulfiram moderately restores impaired hepatic redox status of rats subchronically exposed to cadmium

Examination of cadmium (Cd) toxicity and disulfiram (DSF) effect on liver was focused on oxidative stress (OS), bioelements status, morphological and functional changes. Male Wistar rats were intraperitoneally treated with 1mg CdCl2/kg BW/day; orally with 178.5 mg DSF/kg BW/day for 1, 3, 10 and 21 days; and co-exposed from 22nd to 42nd day. The co-exposure nearly restored previously suppressed total superoxide dismutase (SOD), catalase (CAT) and increased glutathione peroxidase (GPx) activities; increased previously reduced glutathione reductase (GR) and total glutathione-S-transferase (GST) activities; reduced previously increased superoxide anion radical (O-2(center dot-)) and malondialdehyde (MDA) levels; increased zinc (Zn) and iron (Fe), and decreased copper (Cu) (yet above control value), while magnesium (Mg) was not affected; and decreased serum alanine aminotransferases (ALT) levels. Histopathological examination showed signs of inflammation process as previously demonstrated by exposure to Cd. Overall, we ascertained partial liver redox status improvement, compared with the formerly Cd-induced impact

Bi-fractional transforms in phase space

The displacement operator is related to the displaced parity operator through a two dimensional Fourier transform. Both operators are important operators in phase space and the trace of both with respect to the density operator gives the Wigner functions (displaced parity operator) and Weyl functions (displacement operator). The generalisation of the parity-displacement operator relationship considered here is called the bi-fractional displacement operator, O(α, β; θα, θβ). Additionally, the bi-fractional displacement operators lead to the novel concept of bi-fractional coherent states. The generalisation from Fourier transform to fractional Fourier transform can be applied to other phase space functions. The case of the Wigner-Weyl function is considered and a generalisation is given, which is called the bi-fractional Wigner functions, H(α, β; θα, θβ). Furthermore, the Q−function and P−function are also generalised to give the bi-fractional Q−functions and bi-fractional P−functions respectively. The generalisation is likewise applied to the Moyal star product and Berezin formalism for products of non-commutating operators. These are called the bi-fractional Moyal star product and bi-fractional Berezin formalism. Finally, analysis, applications and implications of these bi-fractional transforms to the Heisenberg uncertainty principle, photon statistics and future applications are discussed