Sequential detection of multiple phase transitions in model biological membranes using a red-emitting conjugated polyelectrolyte.

The anionic conjugated polyelectrolyte, poly[3-(6-sulfothioatehexyl)thiophene] (P3Anionic), functions as a highly sensitive probe of membrane order, uniquely capable of sequentially detecting the three key phase transitions occurring within model phospholipid bilayers. The observed sensitivity is the result of charge-mediated, selective localisation of P3Anionic within the head-groups of the phospholipid bilayer

Novel approach of high cell density recombinant bioprocess development: Optimisation and scale-up from microlitre to pilot scales while maintaining the fed-batch cultivation mode of E. coli cultures

<p>Abstract</p> <p>Background</p> <p>Bioprocess development of recombinant proteins is time consuming and laborious as many factors influence the accumulation of the product in the soluble and active form. Currently, in most cases the developmental line is characterised by a screening stage which is performed under batch conditions followed by the development of the fed-batch process. Performing the screening already under fed-batch conditions would limit the amount of work and guarantee that the selected favoured conditions also work in the production scale.</p> <p>Results</p> <p>Here, for the first time, high throughput multifactorial screening of a cloning library is combined with the fed-batch technique in 96-well plates, and a strategy is directly derived for scaling to bioreactor scale. At the example of a difficult to express protein, an RNase inhibitor, it is demonstrated that screening of various vector constructs and growth conditions can be performed in a coherent line by (i) applying a vector library with promoters and ribosome binding sites of different strength and various fusion partners together with (ii) an early stage use of the fed-batch technology. It is shown that the EnBase^®technology provides an easy solution for controlled cultivation conditions in the microwell scale. Additionally the high cell densities obtained provide material for various analyses from the small culture volumes. Crucial factors for a high yield of the target protein in the actual case were (i) the fusion partner, (ii) the use of of a mineral salt medium together with the fed-batch technique, and (iii) the preinduction growth rate. Finally, it is shown that the favorable conditions selected in the microwell plate and shake flask scales also work in the bioreactor.</p> <p>Conclusions</p> <p>Cultivation media and culture conditions have a major impact on the success of a screening procedure. Therefore the application of controlled cultivation conditions is pivotal. The consequent use of fed-batch conditons from the first screening phase not only shortens the developmental line by guarantying that the selected conditions are relevant for the scale up, but in our case also standard batch cultures failed to select the right clone or conditions at all.</p

I danni del botulino

UnavailableUna ricerca condotta dal gruppo del Dr. Matteo Caleo dell\u27Istituto di Neuroscienze dimostra come il botulino, sostanza normalmente usata in medicina estetica per la riduzione delle rughe del volto, risalendo il sistema nervoso raggiunge il cervello, generando effetti a distanza con la sua azione neurotossica

Charge-Mediated Localization of Conjugated Polythiophenes in Zwitterionic Model Cell Membranes.

The selective engineering of conjugated polyelectrolyte (CPE)-phospholipid interfaces is poised to play a key role in the design of advanced biomedical and biotechnological devices. Herein, we report a strategic study to investigate the relationship between the charge of the CPE side group and their association with zwitterionic phospholipid bilayers. The interaction of dipalmitoylphosphatidylcholine (DPPC) phospholipid vesicles with a series of poly(thiophene)s bearing zwitterionic, cationic, or anionic terminal groups (P3Zwit, P3TMAHT and P3Anionic, respectively) has been probed. Although all CPEs showed an affinity for the zwitterionic vesicles, the calculated partition coefficients determined using photoluminescence spectroscopy suggested preferential incorporation within the lipid bilayer in the order P3Zwit > P3Anionic ≫ P3TMAHT. The polarity probe Prodan was used to further qualify the position of the CPE inside the vesicle bilayers via Förster resonance energy transfer (FRET) studies. The varying proximity of the CPEs to Prodan was reflected in the Stern-Volmer quenching constants and decreased in the order P3Anionic > P3TMAHT ≫ P3Zwit. Dynamic light scattering measurements showed an increase in the hydrodynamic diameter of the DPPC vesicles upon addition of each poly(thiophene), but to the greatest extent for P3Anionic. Small-angle neutron scattering studies also revealed that P3Anionic specifically increased the thickness of the headgroup region of the phospholipid bilayer. Epifluorescence and atomic force microscopy imaging showed that P3TMAHT formed amorphous agglomerates on the vesicle surface, P3Zwit was buried throughout the bilayer, and P3Anionic formed a shell of protruding chains around the surface, which promoted vesicle fusion. The global data indicate three distinctive modes of interaction for the poly(thiophene)s within DPPC vesicles, whereby the nature of the association is ultimately controlled by the pendant charge group on each CPE chain. Our results suggest that charge-mediated self-assembly may provide a simple and effective route to design luminescent CPE probes capable of specific localization within phospholipid membranes

Piperidino Substituted [1]Borametallocenophanes. Synthesis, Reactivity, and Structure

ansa-Metallocenes and related complexes have considerable potential as catalyst precursors in the Ziegler-Natta type olefin polymerization. In the present paper we report about the synthesis of piperidinyl-substituted [1]borametallocenophanes of titanium and zirconium. Furthermore, the first example of a base stabilized alkyl-substituted [1]borazirconocenophane was fully characterized and tested for its properties in the polymerization of ethene

π-Diradical Aromatic Soot Precursors in Flames.

Soot emitted from incomplete combustion of hydrocarbon fuels contributes to global warming and causes human disease. The mechanism by which soot nanoparticles form within hydrocarbon flames is still an unsolved problem in combustion science. Mechanisms proposed to date involving purely chemical growth are limited by slow reaction rates, whereas mechanisms relying on solely physical interactions between molecules are limited by weak intermolecular interactions that are unstable at flame temperatures. Here, we show evidence for a reactive π-diradical aromatic soot precursor imaged using non-contact atomic force microscopy. Localization of π-electrons on non-hexagonal rings was found to allow for Kekulé aromatic soot precursors to possess a triplet diradical ground state. Barrierless chain reactions are shown between these reactive sites, which provide thermally stable aromatic rim-linked hydrocarbons under flame conditions. Quantum molecular dynamics simulations demonstrate physical condensation of aromatics that survive for tens of picoseconds. Bound internal rotors then enable the reactive sites to find each other and become chemically cross-linked before dissociation. These species provide a rapid, thermally stable chain reaction toward soot nanoparticle formation and could provide molecular targets for limiting the emission of these toxic combustion products

Challenges and Opportunities for Improving Eco-Efficiency of Tropical Forage-Based Systems to Mitigate Greenhouse Gas Emissions

Forage-based livestock production plays a key role in national and regional economies, for food security and poverty alleviation. Livestock production is also considered as a major contributor to agricultural GHG emissions, however. While demand for livestock products is predicted to continue to increase, there is political and societal pressure both to reduce environmental impacts and to convert some of the pasture area to alternative uses such as crop production and environmental conservation. Thus it is essential to develop approaches for sustainable intensification of livestock systems to mitigate GHG emissions, addressing biophysical, socioeconomic and policy challenges. This paper highlights the potential of improved tropical forages in crop-livestock systems, and linked with policy incentives, to enhance livestock production while reducing its environmental footprint. We give examples for sustainable intensification to mitigate GHG emissions based on improved forages in Brazil and Colombia and suggest future perspectives

Building a National IoT Plan: Policy Recommendations and the Case of Brazil

The Internet of Things (“IoT”) is an expression that refers to a whole set of new services and devices that includes at least three fundamental aspects: connectivity, use of sensors or actuators, and computational capacity for data processing and storage. The Internet of Things goes beyond connecting objects to each other; it also gives them the power to process data (thereby making them "smart"). For developing countries such as Brazil, the opportunities offered by the Internet of Things can compensate for shortcomings in infrastructure and services, and can improve innovation, quality of life, productivity, and even the economic complexity of our basket of export products. However, the way in which each country will seize this opportunity will depend on its specific aspirations and strategies. The broader economic, social, political, and legal context of the country should be considered, as well as the local development of information and communication technologies. For this reason, the National Bank for Economic and Social Development (BNDES), in partnership with the Ministry of Science, Technology, Innovation and Communications (MCTIC), has commissioned this study, "Internet of Things: An Action Plan for Brazil." This study, mapped by a consortium comprised by McKinsey & Company, the CPqD Foundation, and Pereira Neto | Macedo Law Firm, outlines the local technological and economic challenges related to the topic, as well as well as how to address legal issues inherent to the development of IoT in Brazil