Biologically Inspired Design of Protein-Silica Hybrid Nanoparticles for Drug Delivery Applications

The design and application of effective drug carriers is a fundamental concern in the delivery of therapeutics for the treatment of cancer and other vexing health problems. Traditionally utilized chemotherapeutics are limited in efficacy due to poor bioavailability as a result of their size and solubility as well as significant deleterious effects to healthy tissue through their inability to preferentially target pathological cells and tissues, especially in treatment of cancer. Thus, a major effort in the development of nanoscopic drug delivery vehicles for cancer treatment has focused on exploiting the inherent differences in tumor physiology and limiting the exposure of drugs to non-tumorous tissue, which is commonly achieved by encapsulation of chemotherapeutics within macromolecular or supramolecular carriers that incorporate targeting ligands and that enable controlled release. The overall aim of this work is to engineer a hybrid nanomaterial system comprised of protein and silica and to characterize its potential as an encapsulating drug carrier. The synthesis of silica, an attractive nanomaterial component because it is both biocompatible as well as structurally and chemically stable, within this system is catalyzed by self-assembled elastin-like polypeptide (ELP) micelles that incorporate of a class of biologically-inspired, silica-promoting peptides, silaffins. Furthermore, this methodology produces near-monodisperse, hybrid inorganic/micellar materials under mild reaction conditions such as temperature, pH and solvent. This work studies this material system along three avenues: 1) proof-of-concept silicification (i.e. the formation and deposition of silica upon organic materials) of ELP micellar templates, 2) encapsulation and pH-triggered release of small, hydrophobic chemotherapeutics, and 3) selective silicification of templates to potentiate retention of peptide targeting ability.

Mercury content and isotopic composition of frost flower, surface snow and brine samples near Barrow, Alaska

Frost flowers are ice crystals that grow on refreezing sea ice leads in Polar Regions by wicking brine from the sea ice surface and accumulating vapor phase condensate. These crystals contain high concentrations of mercury (Hg) and are believed to be a source of reactive halogens, but their role in Hg cycling and impact on the fate of Hg deposited during atmospheric mercury depletion events (AMDEs) are not well understood. We collected frost flowers growing on refreezing sea ice near Barrow, Alaska (U.S.A.) during an AMDE in March 2009 and measured Hg concentrations and Hg stable isotope ratios in these samples to determine the origin of Hg associated with the crystals. We observed decreasing Delta199Hg values in the crystals as they grew from new wet frost flowers (mean Delta199Hg = 0.77 ± 0.13 per mil, 1 s.d.) to older dry frost flowers (mean Delta199Hg = 0.10 ± 0.05 per mil, 1 s.d.). Over the same time period, mean Hg concentrations in these samples increased from 131 ± 6 ng/L (1 s.d.) to 180 ± 28 ng/L (1 s.d.). Coupled with a previous study of Hg isotopic fractionation during AMDEs, these results suggest that Hg initially deposited to the local snowpack was subsequently reemitted during photochemical reduction reactions and ultimately accumulated on the frost flowers. As a result of this process, frost flowers may lead to enhanced local retention of Hg deposited during AMDEs and may increase Hg loading to the Arctic Ocean.

Experimental data on photophysiology and growth rates of the invasive foraminifera Amphistegina lobifera showing high thermal tolerance from the Eastern Mediterranean and the Gulf of Aqaba

Invasive species allow an investigation of trait retention and adaptations after exposure to new habitats. Recent work on corals from the Gulf of Aqaba (GoA) shows that tolerance to high temperature persists thousands of years after invasion, without any apparent adaptive advantage. Here we test whether thermal tolerance retention also occurs in another symbiont-bearing calcifying organism. To this end, we investigate the thermal tolerance of the benthic foraminifera Amphistegina lobifera from the GoA (29° 30.14167 N 34° 55.085 E) and compare it to a recent "Lessepsian invader population" from the Eastern Mediterranean (EaM) (32° 37.386 N, 34°55.169 E). We first established that the studied populations are genetically homogenous but distinct from a population in Australia, and that they contain a similar consortium of diatom symbionts, confirming their recent common descent. Thereafter, we exposed specimens from GoA and EaM to elevated temperatures for three weeks and monitored survivorship, growth rates and photophysiology. Both populations exhibited a similar pattern of temperature tolerance. A consistent reduction of photosynthetic dark yields was observed at 34°C and reduced growth was observed at 32°C. The apparent tolerance to sustained exposure to high temperature cannot have a direct adaptive importance, as peak summer temperatures in both locations remain <32°C. Instead, it seems that in the studied foraminifera tolerance to high temperature is a conservative trait and the EaM population retained this trait since its recent invasion. Such pre-adaptation to higher temperatures confers A. lobifera a clear adaptive advantage in shallow and episodically high temperature environments in the Mediterranean under further warming.

Natural Fibers for the Production of Green Composites

Development of green composite from natural fibers has gained increasing interests due to the environmental and sustainable benefits when compared with petroleum based non-degradable materials. However, a big challenge of green composites is the diversity of fiber sources, because of the large variation in the properties and characteristics of the lignocellulosic renewable resource. The lignocellulosic fibers/natural fibers used to reinforce green composites are reviewed in this chapter. A classification of fiber types and sources, the properties of various natural fibers, including structure, composition, physical and chemical properties are focused; followed by the impacts of natural fibers on composite properties, with identification of the main pathways from the natural fibers to the green composite. Furthermore, the main challenges and future trend of natural fibers are highlighted.

Give and You Shall Receive: Investing in the Careers of Women Professionals

Purpose – The purpose of this paper is to explore what organizations can do to facilitate the retention and advancement of women professionals into top leadership positions. A social exchange framework is applied to examine ways organizations can signal support for and investment in the careers of women professionals, and ultimately the long-term work relationship. Design/methodology/approach – This paper employed a qualitative methodology; specifically, semi-structured interviews with 20 women executives, in primarily the US hospitality industry, were conducted. The interviews were recorded, transcribed, and content analyzed. Findings – Organizations are likely to strengthen the retention of their female professionals if they signal support through purposeful, long-term career development that provides a sightline to the top, and ultimately creates more female role models in senior-level positions. Organizations can also signal support through offering autonomy over how work is completed, and designing infrastructures of support to sustain professionals during mid-career stages. Findings are used to present a work-exchange model of career development. Research limitations/implications – This research is an exploratory study that is limited in its scope and generalizability. Practical implications – The proposed work-exchange model can be used to comprehensively structures initiatives that would signal organizational support to – and long-term investment in – female professionals and enable them to develop their career paths within their organizations. Originality/value – Through offering a work-exchange model of career development, this paper identifies components of organizational support from a careers perspective, and highlights the factors that could potentially contribute to long-term growth and retention of women professional

Protocolos para a colocação e remoção de espigões

A utilização de espigões em dentes tratados endodonticamente é um dos temas mais estudados em Medicina Dentária. As opiniões são divergentes em relação aos procedimentos clínicos e materiais a serem utilizados para a colocação e remoção de espigões. O objetivo deste trabalho foi realizar uma revisão bibliográfica de forma a organizar conceitos e princípios clínicos para melhor esclarecer os fatores que determinam a necessidade de colocação, utilização e escolha do tipo de espigão, sua cimentação e técnicas para a remoção. Foram analisadas as características e propriedades dos cimentos de fosfato de zinco, ionômero de vidro, cimentos resinosos de polimerização química, polimerização dupla, foto-polimerizável e os sistemas adesivos etch and rinse, self etch e autoadesivos, bem como as técnicas para a remoção de espigões cimentados com diferentes cimentos e sistemas adesivos para depois acessar o remanescente de guta percha para o retratamento endodôntico. Foi feita uma pesquisa bibliográfica na base de dados electrónica PubMed, Google Scholar e RCAAP com as seguintes palavras chave: “Espigões”; “Retratamento Endodôntico”; “Ionómero de Vidro”; “Fosfato de Zinco”; “Cimentos Resinosos”; “Posts”; “Endodontic Retreatment”; “Glass Ionomer”; Zinc-phosphate”; “Resin Cements"; “Push Out Test”; “Posts AND Removal”. Concluiu-se que a cimentação de espigões pré-fabricados de fibra de vidro com cimentos resinosos de dupla polimerização associados aos sistemas adesivos self etch estão gradualmente substituindo os outros tipos de espigões e demais cimentos e possibilitam restaurar o dente de forma adequada e duradoura. E o uso de ultrassons apresenta maior eficácia e segurança na remoção dos espigões.

Fiber Bragg Gratings Strain Sensors for Railway Applications

Fiber optical sensors have played an important role in applications for monitoring the health of civil infrastructures, such as bridges, oil rigs, and railroads. Due to the reduction in cost of fiber-optic components and systems, fiber optical sensors have been studied extensively for their higher sensitivity, precision and immunity to electrical interference compared to their electrical counterparts. A fiber Bragg grating (FBG) strain sensor has been employed for this study to detect and distinguish normal and lateral loads on rail tracks. A theoretical analysis of the relationship between strain and displacement under vertical and horizontal strains on an aluminum beam has been performed, and the results are in excellent agreement with the measured strain data. Then a single FBG sensor system with erbium-doped fiber amplifier broadband source has been carried out. Force and temperature applied on the system have resulted in changes of 0.05 nm per 50 με and 0.094 nm per 10 oC at the center wavelength of the FBG. Furthermore, a low cost fiber-optic sensor system with a distributed feedback (DFB) laser as the light source has been implemented. We show that it has superior noise and sensitivity performances compared to strain gauge sensors. The design has been extended to accommodate multiple sensors with negligible cross talk. When two cascaded sensors on a rail track section are tested, strain readings of the sensor 20 inches away from the position of applied force decay to one seventh of the data of the sensor at the applied force location. The two FBG sensor systems can detect 1 ton of vertical load with a square wave pattern and 0.1 ton of lateral loads (3 tons and 0.5 ton, respectively, for strain gauges). Moreover, a single FBG sensor has been found capable of detecting and distinguishing lateral and normal strains applied at different frequencies. FBG sensors are promising alternatives to electrical sensors for their high sensitivity,ease of installation, and immunity to electromagnetic interferences.

Marvel Cinematic Universe in translation: a study of intertextual coherence and inter-filmic discourse

The primary objective of the present thesis was to determine the extent of intertextual coherence and inter-filmic discourse retained in the Finnish DVD subtitles of the first twelve feature films set in the Marvel Cinematic Universe and ten episodes of the first season of Agents of S.H.I.E.L.D., a transmedia extension of the MCU. The cinematic world of Marvel was chosen as research data in this study for the inherence, abundance, and conspicuousness of its intertextuality. Two categories through which to retain intertextual coherence in translation were set as the premise of the study: 1) the consistent application of the same form of MCU-related proper names in translation and 2) the retention of MCU-related allusions in translation when the retention of the allusion is a strategic choice. The data was collected and analyzed primarily in this juxtaposition. The examination of the gathered data and the set research questions necessitated the division of audiovisual allusions into three categories: verbal visual allusions, secondary spoken allusions, and primary spoken allusions, the last of which was further divided into ambiguous and unambiguous types. Because of their qualitative inadequacies, unambiguous primary spoken allusions were not eligible as data in the present study. 33.3 percent of the proper names qualified as data were translated consistently in each installment they were referenced. In terms of allusions, 76.2 percent of the qualified source-text instances were retained in translation. The results indicate that intertextual elements are more easily identified and retained within the context of one narrative than when this requires the observation of multiple connected narratives as one interwoven universe.

Development of a whole cell biochip for toxicant detection.

In the development of biosensors for ecotoxicity testing it is desirable to produce a small, portable system that can be used in the field. Toxicity testing using bioluminescence is widely used in the laboratory utilising natural and genetically modified (lux/ luc-marked) bacteria and other microorganisms. It is currently not possible to use genetically manipulated microorganisms in field testing and a biosensor, therefore, that incorporates naturally luminescent organisms may be preferred. In the development of a biosensor it is aimed to use the naturally luminescent bacterium Vibrio fischeri as a toxicity detection system on a chip. The bacterium will be immobilised in a polymeric matrix. Current work deals with the optimisation of light output and light preservation within the bacterium prior to immobilisation in polyvinyl alcohol. An examination of a range of physicochemical conditions within the polymer will be made, including cell density, thickness of polymer film, growth and light induction environment, and, preservation conditions, in order to develop a testing system giving consistent results over the lifetime of the biosensor. Data will be presented on light production using different culture media for the growth of V. fischeri and retention of light under immobilised conditions. .

Estudo das propriedades físico-químicas e avaliação de compostos bioativos em 'Physalis peruviana L.'

O rápido crescimento da procura e na produção de Physalis está associado às suas características nutracêuticas e medicinais, por estarem associadas ao bemestar e à saúde. O reconhecimento e o conceito da qualidade dos frutos é cada vezmais importante, abrangendo a aparência do produto, o aroma, a textura e o valor nutricional. Com a realização deste trabalho pretendeu-se avaliar as propriedades físicoquímicas das bagas de physalis, bem como os conteúdos em compostos bioativos com potenciais benefícios para a saúde humana. Neste trabalho foi avaliada uma variedade de physalis (Physalis peruviana L.), sendo os frutos provenientes de uma exploração localizada na região Norte-Centro de Portugal. Foram realizadas análises físicas às 'physalis' frescas, tendo sido determinados o calibre, a cor e a textura. Na análise química, realizaram-se as determinações, da humidade, da fibra bruta, dos açúcares totais e redutores, da acidez total titulável, do teor de sólidos solúveis totais, do ácido ascórbico, dos carotenóides, dos compostos fenólicos totais, dos orto-difenóis e dos flavonóides. Foi ainda determinada a atividade antioxidante pelos métodos ABTS e DPPH e os extratos submetidos a condições simulantes do trato digestivo. As physalis em estudo apresentaram, em média um diâmetro de 1,69 cm e uma massa de 2,77 g. Relativamente à cor, as bagas apresentaram-se claras, (L*=65,72), e com uma tendência para a cor vermelha (a*=16,69), e uma forte intensidade amarela (b*=58,11). No que diz respeito à textura, a firmeza foi de 2,40 N e a elasticidade foi de 2,94 mm. Quanto à caracterização química foram encontrados os seguintes resultados: 83,02% de água, 4,61% de fibra, 8,79% de açúcares totais, 1,25% de acidez total, expressa em ácido cítrico. A amostra continha ainda 5,95 μg/g de carotenoides 26,7 mg de ácido ascórbico por 100 g. Os valores de fenóis totais (42,74 e 59,95 mg EAG/100 g) e de atividade antioxidante determinada pelo método DPPH (7,73 e 9,61 μmol TE/g), e pelo método ABTS (12,28 e 13,71 μmol TE/g) variam de acordo com as condições de extração. Verificou-se ainda uma correlação forte entre os dois métodos. No que diz respeito às condições in vitro de simulação das condições do trato digestivo, verificou-se um decréscimo ao longo do trato digestivo tanto no teor em compostos fenólicos bem como na atividade antioxidante. Em termos globais houve uma retenção de 43% dos compostos fenólicos totais e 26% da atividade antioxidante.

Optimizing Western Blots for the Detection of Endogenous α-Synuclein in the Enteric Nervous System

International audience

The Spatial Convergence of Knowledge in Portugal

Human resources are an essential element in territorial development. When these are characterized by a high level of training, they also enhance a number of effects in fundamental areas of binomial territorial-social cohesion. In this respect, the existence of higher education institutions throughout the territory allows the spread of human resources’ qualification but, by itself, does not guarantee the retention of these resources in different regions. Thus, the objective of this paper is to undertake a spatial analysis of convergence of knowledge through studying the evolution of the percentage of population with higher education in the periods elapsed between the last three censuses in Portugal. Although that percentage has risen appreciably, the convergence is shown to be (very) insignificant.

Espionage against Poland in the Documents and Analyses of the Polish Special Services (1944 - 1989) - as Illustrated by the Intelligence Activities of the USA

The text analyses the intelligence activity against Poland in the period 1944-1989. The paper also contains a case study, i.e. an analysis of the American intelligence service activity held against Poland. While examining the research thesis, the author used the documents and analyses prepared by the Ministry of Internal Affairs. In order to best illustrate the point, the author presented a number of cases of persons who spied for the USA, which was possible thanks to the analysis of the training materials of the Ministry of Internal Affairs directed to the officers of the Security Service and the Citizens’ Militia. The text tackles the following issues: (1) to what extent did the character of the socio-political system influence the number of persons convicted for espionage against Poland in the period under examination?, (2) what was the level of interest of the foreign intelligence services in Poland before the year 1990?, (3) is it possible to indicate the specificity of the U.S. intelligence activity against Poland? 1) The analysis of data indicates that the period 1946-1956 witnessed a great number of convictions for espionage, which is often associated with the peculiar political situation in Poland of that time. Up to 1953, the countries of the Eastern bloc had reproduced the Stalin’s system, which only ceased due to the death of Stalin himself. Since then, the communist systems gradually transformed into the system of nomenklatura. Irrespective of these changes, Poland still witnessed a wave of repressions, which resulted from the threats continuously looming over the communist authorities – combating the anti-communist underground movement, fighting with the Ukrainian Insurgent Army, the Polish government-in-exile, possible revisionism of borders, social discontent related to the socio-political reforms. Hence, a great number of convictions for espionage at that time could be ascribed to purely political sentences. Moreover, equally significant was the fact that the then judicial practice was preoccupied assessing negatively any contacts and relations with foreigners. This excessive number of convictions could ensue from other criminal-law provisions, which applied with respect to the crimes against the State, including espionage. What is also important is the fact that in the Stalin’s period the judiciary personnel acquired their skills and qualifications through intensive courses in law with the predominant spirit of the theory of evidence and law by Andrey Vyshinsky. Additionally, by the decree of 1944 the Penal Code of the Polish Armed Forces was introduced; the code envisaged the increase in the number of offences classified as penalised with death penalty, whereas the high treason was subject to the military jurisdiction (the civilians were prosecuted in military courts till 1955; the espionage, however, still stood under the military jurisdiction). In 1946, there was introduced the Decree on particularly dangerous crimes in the period of the State’s recovery, which was later called a Small Penal Code. 2) The interest that foreign intelligence services expressed in relation to Poland was similar to the one they had in all countries of Eastern and Central Europe. In the case of Poland, it should be noted that foreign intelligence services recruited Polish citizens who had previously stayed abroad and after WWII returned to their home country. The services also gathered information from Poles staying in immigrant camps (e.g. in FRG). The activity of the American intelligence service on the territory of FRG and West Berlin played a key role. The documents of the Ministry of Internal Affairs pointed to the global range of this activity, e.g. through the recruitment of Polish sailors in the ports of the Netherlands, Japan, etc. In line with the development in the 1970s, espionage, which had so far concentrated on the defence and strategic sectors, became focused on science and technology of the People’s Republic of Poland. The acquisition of collaborators in academic circles was much easier, as PRL opened to academic exchange. Due to the system of visas, the process of candidate selection for intelligence services (e.g. the American) began in embassies. In the 1980s, the activity of the foreign intelligence services concentrated on the specific political situation in Poland, i.e. the growing significance of the “Solidarity” social movement. 3) The specificity of the American intelligence activity against Poland was related to the composition of the residency staff, which was the largest in comparison to other Western countries. The wide range of these activities can be proved by the quantitative data of convictions for espionage in the years 1944-1984 (however, one has to bear in mind the factors mentioned earlier in the text, which led to the misinterpretation of these data). Analysing the data and the documents prepared by the Ministry of Internal Affairs, one should treat them with caution, as, frequently, the Polish counter-intelligence service used to classify the ordinary diplomatic practice and any contacts with foreigners as espionage threats. It is clearly visible in the language of the training materials concerned with “secret service methods of the intelligence activity” as well as in the documents on operational activities of the Security Service in relation to foreigners. The level of interest the USA had in Poland was mirrored in the classification of diplomatic posts, according to which Warsaw occupied the second place (the so-called Group “B”) on the three-point scale. The CIA experienced spectacular defeats during their activity in Poland: supporting the Polish underground anti-communist organisation Freedom and Independence and the so-called Munich-Berg episode (both cases took place in the 1950s). The text focuses only on selected issues related to the espionage activities against Poland. Similarly, the analysis of the problem has been based on selected sources, which has limited the research scope - however, it was not the aim of the author to present the espionage activity against Poland in a comprehensive way. In order to assess the real threat posed by the espionage activity, one should analyse the case of persons convicted for espionage in the period 1944-1989, as the available quantitative data, mentioned in the text, cannot constitute an explicit benchmark for the scale of espionage activity. The inaccuracies in the interpretation of data and variables, which can affect the evaluation of this phenomenon, have been pointed out in the text.