Impact of an Engineered Copper-Titanium Dioxide Nanocomposite and Parent Substrates on the Bacteria Viability,Antioxidant Enzymes and Fatty Acid Profiling

Due to the systematic increase in the production of nanomaterials (NMs) and their applications in many areas of life, issues associated with their toxicity are inevitable. In particular, the performance of heterogeneous NMs, such as nanocomposites (NCs), is unpredictable as they may inherit the properties of their individual components. Therefore, the purpose of this work was to assess the biological activity of newly synthesized Cu/TiO₂-NC and the parent nanoparticle substrates Cu-NPs and TiO₂-NPs on the bacterial viability, antioxidant potential and fatty acid composition of the reference Escherichia coli and Bacillus subtilis strains. Based on the toxicological parameters, it was found that B. subtilis was more sensitive to NMs than E. coli. Furthermore, Cu/TiO₂-NC and Cu-NPs had an opposite effect on both strains, while TiO₂-NPs had a comparable mode of action. Simultaneously, the tested strains exhibited varied responses of the antioxidant enzymes after exposure to the NMs, with Cu-NPs having the strongest impact on their activity. The most considerable alternations in the fatty acid profiles were found after the bacteria were exposed to Cu/TiO₂-NC and Cu-NPs. Microscopic images indicated distinct interactions of the NMs with the bacterial outer layers, especially in regard to B. subtilis. Cu/TiO₂-NC generally proved to have less distinctive antimicrobial properties on B. subtilis than E. coli compared to its parent components. Presumably, the biocidal effects of the tested NMs can be attributed to the induction of oxidative stress, the release of metal ions and specific electrochemical interactions with the bacterial cells.     

Structure−Activity Relationships of Cinnamate Ester Analogues as Potent Antiprotozoal Agents

Protozoal infections are still a global health problem, threatening the lives of millions of people around the world, mainly in impoverished tropical and sub-tropical regions. Thus, in view of the lack of efficient therapies and increasing resistances against existing drugs, this study describes the antiprotozoal potential of synthetic cinnamate ester analogues and their structure-activity relationships. In general, Leishmania donovani and Trypanosoma brucei were quite susceptible to the compounds in a structure-dependent manner. Detailed analysis revealed a key role of the substitution pattern on the aromatic ring and a marked effect of the side chain on the activity against these two parasites. The high antileishmanial potency and remarkable selectivity of the nitro-aromatic derivatives suggested them as promising candidates for further studies. On the other hand, the high in vitro potency of catechol-type compounds against T. brucei could not be extrapolated to an in vivo mouse model.     

Scaling planar silicon devices

The generation-over-generation scaling of critical CMOS technology parameters is ultimately bound by nonscalable limitations, such as the thermal voltage and the elementary electronic charge. Sustained improvement in performance and density has required the introduction of new device structures and materials. Partially depleted SOI, a most recent MOSFET innovation, has extended VLSI performance while introducing unique idiosyncrasies. Fully depleted SOI is one logical extension of this device design direction. Gate dielectric tunneling, device self-heating, and single-event upsets present developers of these next-generation devices with new challenges. Strained silicon and high-permittivity gate dielectric are examples of new materials that will enable CMOS developers to continue to deliver device performance enhancements in the sub-100 nm regime.     

Viral dynamics of primary viremia and antiretroviral therapy in simian immunodeficiency virus infection

Mathematical modeling of viral replication dynamics, based on sequential measurements of levels of virion-associated RNA in plasma during antiretroviral treatment, has led to fundamental new insights into human immunodeficiency virus type 1 pathogenesis. We took advantage of the simian immunodeficiency virus (SIV)-infected macaque model to perform detailed measurements and mathematical modeling during primary infection and during treatment of established infection with the antiretroviral drug (R)-9-(2-phosphonylmethoxypropyl)adenine (PMPA). The calculated clearance half-life for productively infected cells during resolution of the peak viremia of primary infection was on the order of 1 day, with slightly shorter clearance half-lives calculated during PMPA treatment. Viral reproduction rates upon discontinuation of PMPA treatment after 2 weeks were approximately twofold greater than those obtained just prior to initiation of treatment in the same animals, likely reflecting accumulation of susceptible target cells during treatment. The basic reproductive ratio (R0) for the spread of SIV infection in vivo, which represents the number of productively infected cells derived from each productively infected cell at the beginning of infection, was also estimated. This parameter quantifies the extent to which antiviral therapy or vaccination must limit the initial spread of virus to prevent establishment of chronic disseminated infection. The results thus provide an important guide for efforts to develop vaccines against SIV and, by extension, human immunodeficiency virus.     

Finite constants: characterizations of a new decidable set of constants

Constant propagation, the replacement of program terms which represent a unique value at run time by their values, is a classical program optimization method. In spite of being treated for years, constant propagation still has been in the unsatisfactory phase of heuristics. We enhance the known constant propagation techniques to obtain an algorithm which is optimal for programs without loops. Fundamental is the introduction of a new decidable set of constants, the finite constants. This set has two different characterizations: a denotational one, which directly specifies our iterative algorithm and an operational one, which delivers the completeness or optimality of this algorithm for programs without loops. The algorithm is implemented in a commercial compiler project.     

Modellqualität als Indikator für Softwarequalität: eine Taxonomie

Zusammenfassung  Komplexit?t, Anforderungsmanagement und Variantenvielfalt sind zentrale Herausforderungen bei der Entwicklung und Evolution heutiger softwaregesteuerter Systeme. Diesen wird zunehmend durch den Einsatz modellbasierter Entwicklungsmethoden begegnet. Dadurch wird das Modell zum zentralen Artefakt und die Erstellung und Nutzung von Modellen zu einer zentralen T?tigkeit in der Softwareentwicklung. Mit der Bedeutung der Modelle steigen auch die Ansprüche an ihre Qualit?t. Dieser Beitrag untersucht die Implikationen, die daraus entstehen, insbesondere werden sinnvolle Qualit?tsmerkmale für softwarebeschreibende Modelle identifiziert und diskutiert.     

What do we learn from binding features? Evidence for multilevel feature integration.

Four experiments were conducted to investigate the relationship between the binding of visual features (as measured by their aftereffects on subsequent binding) and the learning of feature-conjunction probabilities. Both binding and learning effects were obtained, but they did not interact. Interestingly, (shape-color) binding effects disappeared with increasing practice, presumably because of the fact that only 1 of the features involved was relevant to the task. However, this instability was only observed for arbitrary, not highly overlearned combinations of simple geometric features and not for real objects (colored pictures of a banana and strawberry), where binding effects were strong and resistant to practice. These findings suggest that learning has no direct impact on the strength or resistance of bindings or on speed with which features are bound; however, learning does affect the amount of attention particular feature dimensions attract, which again can influence which features are considered in binding. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Zur Frage der Elastizität,der Beanspruchung und der Festigkeit warmbetriebener Rohrleitungen

Zusammenfassung Die Entwicklung der Dampfkraftanlagen zu immer h?heren Temperaturen, Drücken und Leistungen zwingt den Rohrleitungsbauer, sich noch eingehender als bisher mit den Fragen der Elastizit?t, der Beanspruchung und der Festigkeit der Rohrleitung zu besch?ftigen. Zu einigen der wesentlichen Fragen werden im folgenden rechnerische und experimentelle Beitr?ge mitgeteilt. VDI     

Symbolic control of visual attention: The role of working memory and attentional control settings.

This study examined how 1 symbol is selected to control the allocation of attention when several symbols appear in the visual field. In Experiments 1-3, the critical target feature was color, and it was found that uninformative central arrows that matched the color of the target were selected and produced unintentional shifts of attention (i.e., involuntary, initiated slowly, producing long-lasting facilitatory effects). Experiment 4 tested whether such selection is the result of an attentional filter or of a competition bias due to a match of incoming information against integrated object representations stored in working memory. Here, the critical feature was shape and color was irrelevant, but matching color arrows were still selected. Thus, features of objects in working memory will bias the selection of symbols in the visual field, and such selected symbols are capable of producing unintentional shifts of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Novel Readout Electronics for Thickness Shear-Mode Liquid Sensors Compensating for Spurious Conductivity and Capacitances

In this paper, a readout circuit for a thickness shear-mode (TSM) resonator is presented which can be used for sensing applications in liquids such as viscosity sensing. The system features compensation of both spurious capacitances and conductances in parallel to the resonator. This allows measurements even in conductive liquids without the need for an elaborate sealing of the sensor. The influence of the spurious elements is determined by means of two orthogonal synchronous detectors and eliminated by active compensation using voltage-controlled amplifiers (VCAs). Furthermore, the circuit is robust against possible phase errors. The basic concept is discussed in detail, and a readout circuit is developed. A prototype is presented, and sample results are given, demonstrating the feasibility of the approach