Search results for "ACTIVATION"
showing 10 items of 2079 documents
Mode of action of Bacillus thuringiensis PS86Q3 strain in hymenopteran forest pests
2001
The mode of action of Cry toxins has been described principally in lepidopteran insects as a multistep process. In this work we describe the mode of action of a Cry toxin active in the common pine sawfly Diprion pini (Hymenoptera, Diprionidae), considered a major forest pest in Europe. Strain PS86Q3 contains a long bipyramidal crystal composed of five major proteins. The N-terminal sequence shows that the 155 kDa protein corresponds to Cry5B toxin and the other proteins belong to the Cry5A subgroup. PCR analysis indicates the presence of cry5Ac and cry5Ba genes, suggesting that Cry5A protein should be Cry5Ac. Activation of protoxins with trypsin or with midgut content from D. pini and Cepha…
Theory of heterogeneous viscoelasticity
2015
We review a new theory of viscoelasticity of a glass-forming viscous liquid near and below the glass transition. In our model we assume that each point in the material has a specific viscosity, which varies randomly in space according to a fluctuating activation free energy. We include a Maxwellian elastic term and assume that the corresponding shear modulus fluctuates as well with the same distribution as that of the activation barriers. The model is solved in coherent-potential approximation (CPA), for which a derivation is given. The theory predicts an Arrhenius-type temperature dependence of the viscosity in the vanishing-frequency limit, independent of the distribution of the activatio…
Hepatocytes--the choice to investigate drug metabolism and toxicity in man: in vitro variability as a reflection of in vivo.
2007
The pharmaceutical industry is committed to marketing safer drugs with fewer side effects, predictable pharmacokinetic properties and quantifiable drug-drug interactions. Drug metabolism is a major determinant of drug clearance and interindividual pharmacokinetic differences, and an indirect determinant of the clinical efficacy and toxicity of drugs. Progressive advances in the knowledge of metabolic routes and enzymes responsible for drug biotransformation have contributed to understanding the great metabolic variations existing in human beings. Phenotypic as well genotypic differences in the expression of the enzymes involved in drug metabolism are the main causes of this variability. How…
The broad-spectrum antiinfective drug artesunate interferes with the canonical nuclear factor kappa B (NF-κB) pathway by targeting RelA/p65.
2015
Infection with human cytomegalovirus (HCMV) is a serious medical problem, particularly in immunocompromised individuals and neonates. The success of standard antiviral therapy is hampered by low drug compatibility and induction of viral resistance. A novel strategy is based on the exploitation of cell-directed signaling inhibitors. The broad antiinfective drug artesunate (ART) offers additional therapeutic options such as oral bioavailability and low levels of toxic side-effects. Here, novel ART-derived compounds including dimers and trimers were synthesized showing further improvements over the parental drug. Antiviral activity and mechanistic aspects were determined leading to the followi…
Topology Management in wireless sensor networks
2020
Wireless sensor networking is ingratiating itself into almost every area of human endeavors. Its drivers include its usages, improvements in microelectronics and manufacturing techniques. The network is made up of multiple tiny sensor nodes deployed in the area to be sensed, with nodes having processing, communicating, and sensing capabilities that enable them to perform their function collaboratively. Nodes sense events and transmit their data to the sink directly or through intermediate nodes acting as relay.Despite all the tremendous advances that have been made on this technology over the past few years, energy has not kept pace. This is based mostly on the fact that battery is its main…
Inferring slowly-changing dynamic gene-regulatory networks
2015
Dynamic gene-regulatory networks are complex since the interaction patterns between their components mean that it is impossible to study parts of the network in separation. This holistic character of gene-regulatory networks poses a real challenge to any type of modelling. Graphical models are a class of models that connect the network with a conditional independence relationships between random variables. By interpreting these random variables as gene activities and the conditional independence relationships as functional non-relatedness, graphical models have been used to describe gene-regulatory networks. Whereas the literature has been focused on static networks, most time-course experi…
PED Mediates AKT-Dependent Chemoresistance in Human Breast Cancer Cells
2005
Abstract Killing of tumor cells by cytotoxic therapies, such as chemotherapy or gamma-irradiation, is predominantly mediated by the activation of apoptotic pathways. Refractoriness to anticancer therapy is often due to a failure in the apoptotic pathway. The mechanisms that control the balance between survival and cell death in cancer cells are still largely unknown. Tumor cells have been shown to evade death signals through an increase in the expression of antiapoptotic molecules or loss of proapoptotic factors. We aimed to study the involvement of PED, a molecule with a broad antiapoptotic action, in human breast cancer cell resistance to chemotherapeutic drugs–induced cell death. We show…
Mosses as a biomonitor to identify elements released into the air as a result of car workshop activities
2022
Human activity as a result of civilization development contributes to creating new sources of environmental pollution. Air pollution is one of the major problems because it affects the fauna and flora, and people themselves. There is a lack of public awareness of the level of atmospheric analytes pollution emitted from people's occupational and recreational (leisure) activities. A quick, cheap and easy way to investigate the state of the environment is to use organisms-biomonitors that indicate the level of environmental pollution. The study aimed to assess air pollution in an urban area using three moss species: Sphagnum fallax, Pleurozium schreberi and Dicranum polysetum. Mosses were expo…
Bioenergy chain building: a collective action perspective
2014
Depletion of natural resources has become a key issue on the European policy agenda. Bottom-up measures have emerged in several countries with a view to promoting awareness campaigns and environmental sustainability, with the agenda set by individuals who start up collective initiatives at the local level. Such collective action provides an incentive to free-ride on the contribution of others. Social norms and the consequent behavior of individuals involved in collective action assume a key role in ensuring sustainable use of a public good, achieving significant, long-lasting success. The present study aims to ascertain which determinants most affect farmers’ willingness to contribute to co…
The modulation of immune complex aggregation by classical pathway-mediated reactions.
1985
Abstract Classical pathway (CP)-triggered reactions of complement-modulated immune complex(IC) aggregation (tetanus toxoid/human anti-tetanus toxoid-IgG; ICs of equivalence) were investigated turbidimetrically during the early stages of reaction. Monospecific Fab'- or Fab-fragments (rabbit) directed against certain complement components were used to block the complement function in normal human serum (NHS). Additionally, parts of the reactions were studied using purified complement components. C1q in serum generated by the addition of EDTA as well as purified C1q were found to increase the IC aggregation. In contrast to C1q, macromolecular C1 is able to inhibit IC aggregation, whereas addit…