Disposable MMP-9 sensor based on the degradation of peptide cross-linked hydrogel films using electrochemical impedance spectroscopy

Barts and The London Charity and Queen Mary Innovation Lt

Gating of aquaporins by heavy metals in Allium cepa L. epidermal cells

Changes in the water permeability, aquaporin (AQP) activity, of leaf cells were investigated in response to different heavy metals (Zn2+, Pb2+, Cd2+, Hg2+). The cell pressure probe experiments were performed on onion epidermal cells as a model system. Heavy metal solutions at different concentrations (0.05 μM–2 mM) were used in our experiments. We showed that the investigated metal ions can be arranged in order of decreasing toxicity (expressed as a decrease in water permeability) as follows: Hg>Cd>Pb>Zn. Our results showed that β-mercaptoethanol treatment (10 mM solution) partially reverses the effect of AQP gating. The magnitude of this reverse differed depending on the metal and its concentration. The time course studies of the process showed that the gating of AQPs occurred within the first 10 min after the application of a metal. We also showed that after 20–40 min from the onset of metal treatment, the water flow through AQPs stabilized and remained constant. We observed that irrespective of the metal applied, the effect of AQP gating can be recorded within the first 10 min after the administration of metal ions. More generally, our results indicate that the toxic effects of investigated metal ions on the cellular level may involve AQP gating

FIB patterning of stainless steel for the development of nano-structured stent surfaces for cardiovascular applications

Stent implantation is a percutaneous interventional procedure that mitigates vessel stenosis, providing mechanical support within the artery and as such a very valuable tool in the fight against coronary artery disease. However, stenting causes physical damage to the arterial wall. It is well accepted that a valuable route to reduce in-stent re-stenosis can be based on promoting cell response to nano-structured stainless steel (SS) surfaces such as by patterning nano-pits in SS. In this regard patterning by focused ion beam (FIB) milling offers several advantages for flexible prototyping. On the other hand FIB patterning of polycrystalline metals is greatly influenced by channelling effects and redeposition. Correlative microscopy methods present an opportunity to study such effects comprehensively and derive structure–property understanding that is important for developing improved patterning. In this chapter we present a FIB patterning protocol for nano-structuring features (concaves) ordered in rectangular arrays on pre-polished 316L stainless steel surfaces. An investigation based on correlative microscopy approach of the size, shape and depth of the developed arrays in relation to the crystal orientation of the underlying SS domains is presented. The correlative microscopy protocol is based on cross-correlation of top-view scanning electron microscopy, electron backscattering diffraction, atomic force microscopy and cross-sectional (serial) sectioning. Various FIB tests were performed, aiming at improved productivity by preserving nano-size accuracy of the patterned process. The optimal FIB patterning conditions for achieving reasonably high throughput (patterned rate of about 0.03 mm2/h) and nano-size accuracy in dimensions and shapes of the features are discussed as well

"A Theoretical Perspective on Multi-level Systems in Europe: Constitutional Power and Partisan Conflict"

types: ArticleThis article distinguishes three constitutionally defined categories of multi-level systems – confederations, federal arrangements and regionalized arrangements, which differ in whether their lower-level governments enjoy constitutional protection and whether we find a constitutional hierarchy between central and lower levels of government. We argue that the constitutional category a multi-level system belongs to systematically shapes first, the dominant mode of day-to-day intergovernmental coordination, second, the mode of formal competence (re)allocation; and third, the relative impact of party (in)congruence across central and lower-level governments on these coordination processes, respectively. The article then specifies the indicators used to test the hypotheses across the range of case studies. It finally shows how the multi-level systems covered in this special issue span the confederal – federal – regionalized spectrum and thus allow for an encompassing comparative assessment of multi-level dynamics and their long-term evolution.ESR

Analytical modeling of pulse transformers for power modulators

Figure 2 . Solid-state modulator (1kV/4kA) / transformer for measurement. Abstract -The parasitic capacitances of transformers significantly influence the resulting pulse shape of a power modulator system. In order to predict the pulse shape and optimize the geometry of the pulse transformer before building the transformer, an equivalent circuit and analytic expressions relating the geometry with the parasitic elements are needed. Therefore, a model consisting of 6 equivalent capacitors and a simplified circuit, as well as the belonging equations, are presented. The equations are verified by measurement results for a pulse transformer and a solid-state modulator designed for linear accelerators

Zachowania ptaków krukowatych w stosunku do myszołowa zwyczajnego Buteo buteo na obszarach miejskich i pozamiejskich województwa mazowieckiego

Behaviors of the corvids towards common buzzard Buteo buteo on urban and extra-urban areas of the Mazowieckie Province. The study was based on observations of birds of the crow family (Corvidae) since May till November, during intensive training of a raptor common buzzard Buteo buteo on various areas – urban and extra-urban, of the Mazowieckie Province at various times of the day. A distinct difference was noted in the activity of the corvids depending on land development. In the study period, 305 birds were recorded, the majority of which (n = 276) were noted on the urban area, which constituted 91% of all birds observed in the entire study period. The evaluation was also significantly affected by day time. In the afternoon hours, the activity of birds towards common buzzard was significantly higher and reached 65% on average. A lower activity of the birds was observed on extra-urban areas where representatives of the crow family – Eurasian jay Garrulus glandarius and Eurasian magpie Pica pica – showed minimal interest in the bird of prey. They were undertaking individual attempts of scaring the raptor off, without intensive alerting signals and calling other individuals.Zachowania ptaków krukowatych w stosunku do myszołowa zwyczajnego Buteo buteo na obszarach miejskich i pozamiejskich województwa mazowieckiego. Badania oparto na obserwacjach ptaków z rodziny krukowatych (Corvidae) od maja do końca listopada, podczas intensywnego treningu ptaka drapieżnego myszołowa zwyczajnego Buteo buteo w zróżnicowanych obszarach – miejskim i pozamiejskim, województwa mazowieckiego o różnych porach dnia. Stwierdzono wyraźną różnicę w aktywności krukowatych w zależności od zabudowania terenu. W trakcie prowadzonych badań odnotowano 305 sztuk ptaków, z czego zdecydowaną większość, tzn. 276 sztuk, na terenie miejskim, co stanowiło 91% obserwowanych osobników w ciągu całego okresu badań. Istotny wpływ na ocenę miała również pora dnia. W godzinach przedpołudniowych aktywność ptaków w stosunku do myszołowa zwyczajnego była znacznie większa i wynosiła średnio 65%. Mniejszą aktywność obserwowano na terenach pozamiejskich, gdzie przedstawiciele krukowatych – sójka zwyczajna Garrulus glandarius oraz sroka Pica pica – wykazywały minimalne zainteresowanie ptakiem drapieżnym. Podejmowały one indywidualne próby odstraszenia drapieżnika, bez intensywnych sygnałów ostrzegawczych i nawoływania innych osobników

Visions of Nature in Eastern Europe: A Polish Example

Visions of nature are defined as public views on what nature is, what values are carried by nature and what is the appropriate relationship between humans and nature. They were studied in Lubelski region, Poland. With respect to the first, respondents expressed that human influence and naturalness do not exclude each other. One result of the values survey was that respondents acknowledged nature's intrinsic value. The study into the relationship between humans and nature showed that the respondents adhered strongly to a steward type of relationship, and that more ecocentric images were adhered to for a lesser, but substantial degree.Environment, attitudes, values, environmental awareness, Poland