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See detailThe development of mobility controls
Crutzen, Nathalie ULg; Qian, Wei

Conference (2015, March 26)

Detailed reference viewed: 31 (8 ULg)
See detailDevelopment of molecular tests for simultaneous detection of Erwinias spp infecting potato tubers in Belgium
Moh, Ahoussi Augustin ULg; Roussel, S.; Van mellaert, S. et al

Poster (2005)

Detailed reference viewed: 21 (3 ULg)
See detailDevelopment of molecular tests for the detection of Ilar and latent viruses and Banana Mild Mosaic Virus
Marbot, S.; Reichel, H.; Kummert, J. et al

Conference (2004)

Detailed reference viewed: 20 (1 ULg)
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See detailDevelopment of molecular tests for the detection of ILAR and latent viruses in fruit trees.
Roussel, S.; Kummert, J.; Dutrecq, O. et al

in Communications in Agricultural and Applied Biological Sciences (2004), 69(4), 427-432

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See detailDevelopment of molecular tools for rapid detection and quantification of indoor airborne molds to assess their impact on public health
Libert, Xavier ULg

Doctoral thesis (2017)

Currently, contamination of the indoor environment by fungi is suggested to be a public health problem, although scientific evidence on the causal link is still limited. The monitoring of indoor airborne ... [more ▼]

Currently, contamination of the indoor environment by fungi is suggested to be a public health problem, although scientific evidence on the causal link is still limited. The monitoring of indoor airborne fungal contamination is a common tool to help understanding the link between fungi in houses and respiratory problems. Classical monitoring methods, based on cultivation and microscopic identification, have some limitations. For example, uncultivable or dead fungi (“unknown” fraction) cannot be identified, although they could have an impact on human health. In this context, molecular tools seem to be a valuable alternative. In this PhD work, different molecular tools were developed, from simplex to multiplex, to detect and identify indoor airborne fungi. The goal was to improve the detection of fungal contaminants, including the “unknown” fraction, as compared to the currently used classical monitoring methods. The necessary air sampling and DNA extraction protocols, adapted to the downstream molecular monitoring methods have also been developed. Through the application of the developed tools to specific case studies, we aimed to improve the current knowledge on fungal contamination. At first, we developed a specific ITS-based SYBR®green real-time PCR (qPCR) assay for Aspergillus versicolor, a species frequently observed in indoor air and known to be allergenic. Additionally, an ITS-based qPCR assay was developed for the specific detection of Exophiala jeanselmei, a pathogenic yeast suspected to be a part of the “unknown fraction”. The performance of these qPCR methods was assessed. This comparison demonstrated that SYBR®green qPCR assays can be used as a molecular alternative for monitoring of contaminated samples while eliminating the need for culturing and thereby considerably decreasing the required analysis time. However, qPCR has some limitations especially concerning the discrimination of genetically close species and multiplexing. The first issue was addressed through the use of post-qPCR high resolution melting (HRM) analysis, providing a proof-of-concept for this approach, using 3 closely related Aspergillus, i.e., A. versicolor, Aspergillus creber and Aspergillus sydowii. This HRM tool will allow a more accurate monitoring of these closely related indoor air contaminants, thereby contributing to an improved insight in the causal link between the specific presence of these species and health issues. The multiplexing issue was overcome through a Luminex xMAP® assay, developed for the simultaneous detection of the 10 most frequently in indoor air found fungi. All the species identified with the classical method were also detected with the xMAP® assay, however in a shorter time frame, and using less sample material. This assay will improve the communication with the involved medical team and the patient. To provide scientific evidence for the causal link between indoor airborne fungi and health problems, the full diversity needs however to be identified. This cannot be achieved by using a targeted assay. Therefore, next generation sequencing (NGS) could offer a valuable alternative as an open approach multiplex monitoring method. An NGS-based metagenomics approach was used to investigate the “unknown” agents in air samples of offices in contact with air-conditioning reservoirs and showed the first detection of E. jeanselmei in indoor air. Finally, a metagenomics analysis was performed to investigate the indoor airborne fungal diversity in contaminated residences in Brussels where people with health problems were living. This demonstrated that NGS could contribute to improved data concerning the indoor airborne fungal diversity, as compared to the currently used classical methods. The methods developed in this PhD work and the insights obtained are a first step for a better understanding of the causal link between indoor airborne fungi and public health. [less ▲]

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See detailDevelopment of monoclonal antibodies recognizing 7-(2-hydroxyethyl)guanine and imidazole ring-opened 7-(2-hydroxyethyl)guanine.
Young, T. L.; Habraken, Yvette ULg; Ludlum, D. et al

in Carcinogenesis (1990), 11

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See detailDevelopment of Multiaxial Constitutive Relationships for Concrete
Gernay, Thomas ULg

Scientific conference (2011, March 18)

Recent research in structural fire engineering has shown that concrete or composite building structures can develop unexpected modes of strength when subjected to fire. Under certain conditions, a ... [more ▼]

Recent research in structural fire engineering has shown that concrete or composite building structures can develop unexpected modes of strength when subjected to fire. Under certain conditions, a structure will present a robust behavior that can dramatically increase its fire resistance compared to the fire resistance calculated by a predictive approach. An example of such robust behavior is the membrane action that can be developed by a structural slab in fire. However, the numerical simulation of such behaviors requires the development of reliable and accurate multiaxial constitutive relationships for modelling the behavior of concrete. This presentation is based on the work performed by the author during a six month research stay at CEA Saclay, in the team of Alain Millard. The aim of the research stay was to develop a concrete multiaxial model that can be used for the numerical analysis by the finite elements method of concrete structures in fire. To be able to accurately simulate the structural behavior during every phases of a natural fire, the concrete model includes plasticity and damage phenomena. The main features and parameters of the model are presented and its implementation in the softwares SAFIR and CAST3M is briefly discussed. Then, a few applications are given and the presentation ends with a comment on the remaining issues and perspectives. [less ▲]

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See detailDevelopment of multilayered chitosan-based nanofibers
Croisier, Florence ULg; Aqil, Abdelhafid ULg; Detrembleur, Christophe ULg et al

Poster (2009, June 14)

By combining electrospinning and layer-by-layer deposition techniques, new porous material scaffolds of multilayered, chitosan-based nanofibers were produced. Layer-by-layer (LBL) is a well-known method ... [more ▼]

By combining electrospinning and layer-by-layer deposition techniques, new porous material scaffolds of multilayered, chitosan-based nanofibers were produced. Layer-by-layer (LBL) is a well-known method for surface coating, based on electrostatic interactions. It enables the controllable deposition of a variety of polyelectrolytes including synthetic and natural materials, with designable layer structure, defined layer thickness and size. Electrospinning (ESP) allows the fabrication of polymer fibers ranging from nanometers to a few microns in diameter, depending on the polymer characteristics (a.o. molecular weight, solution viscosity and conductivity) and processing conditions (electric potential, distance between syringe-capillary and collection plate, concentration, flow rate). Mats of nanofibers produced by ESP display a very large surface area-to-volume ratio and high porosity with very small pore size. The nanometric scale of electrospun fibers also proves a positive effect on cellular growth, as fiber mats mimic extracellular matrix structure. The association of these two techniques with the use of biocompatible and biodegradable polymers such as chitosan, gives outstanding prospects in the field of biomedical applications, especially for the preparation of wound dressings, artificial skin or tissue engineering scaffolds. In the present study, a charged copolymer, poly(methylmethacrylate-block-methacrylic acid), was added to a poly(ε-caprolactone) or poly(D,L-lactide) solution before electrospinning in order to prepare surface charged nanofibers. Oppositely charged polyelectrolytes – chitosan and poly(styrene sulfonate) or hyaluronic acid – were then alternately deposited on these aliphatic polyester fiber “cores” using LBL method. The aliphatic polyester core was also removed selectively to confirm the growth of a multilayered shell, obtaining hollow fibers. [less ▲]

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See detailDevelopment of multilayered chitosan-based nanofibers for tissue engineering
Croisier, Florence ULg; Aqil, Abdelhafid ULg; Detrembleur, Christophe ULg et al

Conference (2009, June 13)

By combining electrospinning and layer-by-layer deposition techniques, new porous material scaffolds of multilayered, chitosan-based nanofibers were produced. Layer-by-layer (LBL) is a well-known method ... [more ▼]

By combining electrospinning and layer-by-layer deposition techniques, new porous material scaffolds of multilayered, chitosan-based nanofibers were produced. Layer-by-layer (LBL) is a well-known method for surface coating, based on electrostatic interactions. It enables the controllable deposition of a variety of polyelectrolytes including synthetic and natural materials, with designable layer structure, defined layer thickness and size. Electrospinning (ESP) allows the fabrication of polymer fibers ranging from nanometers to a few microns in diameter, depending on the polymer characteristics (a.o. molecular weight, solution viscosity and conductivity) and processing conditions (electric potential, distance between syringe-capillary and collection plate, concentration, flow rate). Mats of nanofibers produced by ESP display a very large surface area-to-volume ratio and high porosity with very small pore size. The nanometric scale of electrospun fibers also proves a positive effect on cellular growth, as fiber mats mimic extracellular matrix structure. The association of these two techniques with the use of biocompatible and biodegradable polymers such as chitosan, gives outstanding prospects in the field of biomedical applications, especially for the preparation of wound dressings, artificial skin or tissue engineering scaffolds. In the present study, a charged copolymer, poly(methylmethacrylate-block-methacrylic acid), was added to a poly(ε-caprolactone) or poly(D,L-lactide) solution before electrospinning in order to prepare surface charged nanofibers. Oppositely charged polyelectrolytes – chitosan and poly(styrene sulfonate) or hyaluronic acid – were then alternately deposited on these aliphatic polyester fiber “cores” using LBL method. The aliphatic polyester core was also removed selectively to confirm the growth of a multilayered shell, obtaining hollow fibers. [less ▲]

Detailed reference viewed: 183 (22 ULg)
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See detailDevelopment of natural semiochemical slow-release formulations as biological control devices
Heuskin, Stéphanie ULg; Lorge, Stéphanie ULg; Leroy, Pascal ULg et al

in Ioannou, Efstathia; Roussis, Vassilios (Eds.) Trends in natural products research : a PSE young scientists' meeting, June 12-15, 2011, Kolymvari - Crete. Book of abstracts (2011, June 12)

Semiochemicals – informative molecules used in insect-insect or plant-insect interactions – have been widely considered within various integrated pest management (IPM) strategies. In the present work, two ... [more ▼]

Semiochemicals – informative molecules used in insect-insect or plant-insect interactions – have been widely considered within various integrated pest management (IPM) strategies. In the present work, two sesquiterpenoids, E-β-farnesene and E-β-caryophyllene, were formulated for their properties as aphid enemy attractants. E-β-farnesene, the alarm pheromone of many aphid species, was also identified as a kairomone by attracting aphid predators and parasitoids. E-β-caryophyllene was identified as a potential component of the aggregation pheromone of the Asian ladybird, Harmonia axyridis Pallas, another aphid predator. The two products were purified from essential oils of Matricaria chamomilla L. (Asteraceae) and Nepeta cataria L. (Lamiaceae), respectively. Natural and biodegradable formulations were then investigated in order to deliver these molecules on crop fields for a long period of time as biological control devices. Due to their sensitivity to oxidation, both sesquiterpenes needed to be protected from oxygen degradation. For this purpose, alginate – hydrophilic matrix with low oxygen permeability – was used as polymer for the formulations: the main objective was to deliver semiochemicals in the air in a controlled way. Consequently, a careful selection of alginates was realised. Formulated beads showed different structural and encapsulation properties depending on various formulation factors. Alginate formulations were characterised by texturometry and by confocal microscopy in order to observe the distribution of semiochemicals in alginate network. The last step of alginate bead characterisation consisted in studying release rate of semiochemicals in laboratory-controlled conditions by optimised volatile collection system and validated fast GC analytical procedures Finally, the efficiency of formulations as aphid predator (Syrphidae species) and parasitoid (Aphidius ervi) attractants was demonstrated by field trapping and olfactometry experiments. [less ▲]

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See detailDevelopment of near infrared spectroscopic methods using desirability indexes: How to select the most appropriate calibration model
Ziemons, Eric ULg; De Bleye, Charlotte ULg; Chavez, Pierre-François ULg et al

Conference (2012, May 10)

In the last decade, considerable research and developments dealing with near infrared spectroscopy (NIRS) have taken place in industrial field, especially in pharmaceutical industry. This enthusiasm can ... [more ▼]

In the last decade, considerable research and developments dealing with near infrared spectroscopy (NIRS) have taken place in industrial field, especially in pharmaceutical industry. This enthusiasm can be explained by the fact that NIRS is regarded as promising and attractive tool in Process Analytical Technology (PAT) and Green Chemistry frameworks. Taking into account its non-invasive, non-destructive character, fast data acquisition and the use of probes in on-line, in-line and at-lines, this technique is expected to reach the aims of the latters. However, the development of a NIR quantitative method is not straightforward in comparison with conventional analytical techniques. Its development requires time-consuming reference methods, chemometrics and iterative heuristic approaches to build a model allowing the prediction of the analyte of interest according to the acceptance criteria consistent with the intended use of the method. Facing to the lack of objective decision rule of the traditional chemometric criteria such as R2, RMSEC, RMSECV and RMSEP, it is essential to develop innovative approaches for the selection of the most appropriate calibration model from a models plurality. In this context, a methodology using desirability indexes, such as the Fitting Model Index (FMI), based on tolerance intervals was developed in order to increase significantly the objectivity of the decision process. This latter allows to reduce dramatically the development and the validation steps and thus could ease the implementation of NIR spectroscopy in pharmaceutical industry. [less ▲]

Detailed reference viewed: 60 (14 ULg)
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See detailDevelopment of new assessment tools for attentional and executive functioning in children
Catale, Corinne ULg; Meulemans, Thierry ULg

in Books of Conference Abstract: The 8th European Conference on Psychological Assessment, (2005)

In developmental neuropsychology, attentional and executive impairments are commonly reported following acquired neurological/developmental disorders such as Traumatic Brain Injury (TBI), epilepsy, ADHD… ... [more ▼]

In developmental neuropsychology, attentional and executive impairments are commonly reported following acquired neurological/developmental disorders such as Traumatic Brain Injury (TBI), epilepsy, ADHD… Unfortunately, most of attentional tests used in child neuropsychology were originally developed for adults and are of limited interest for children (notably because of their lack of attractiveness or because they require some non-developed skills). From a cognitive perspective, it is therefore often difficult to interpret the results obtained with such tools in children. The aim of this study was to develop assessment tasks of attentional/executive functioning which are more attractive (by using colored/familiar stimuli) and more theoretically relevant for young children. The tasks are based on Posner’s attentional model, which includes selective and sustained attention, attentional shifting and cognitive inhibition. Eighty children aged from 5 to 11 with no developmental/neurological deficits were administered tasks assessing visual selective attention (selecting a specific character among distractors), sustained attention (crossing dinosaurs in 5 minutes), flexibility (shifting between name and colour of stimuli), and inhibition (naming the real colour of a red banana or a yellow strawberry). Results confirmed the interest of these tasks in the assessment of attentional functioning in children, thanks to both their limited duration of administration and the stimuli’s attractiveness. Furthermore, results showed that tasks are sensitive to attentional development from 5 to 11 years old (p < .05). Finally, a preliminary study showed that some tasks can be particularly sensitive to attentional disorders in a clinical population of TBI children. [less ▲]

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See detailDevelopment of new biomimetic biopolymers
Grandfils, Christian ULg

Scientific conference (2013, June 27)

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See detailDevelopment of new drugs for an old target — the penicillin binding proteins.
Zervosen, Astrid ULg; Sauvage, Eric ULg; Frère, Jean-Marie ULg et al

in Molecules (2012), 17(11), 12478-505

The widespread use of β-lactam antibiotics has led to the worldwide appearance of drug-resistant strains. Bacteria have developed resistance to β-lactams by two main mechanisms: the production of β ... [more ▼]

The widespread use of β-lactam antibiotics has led to the worldwide appearance of drug-resistant strains. Bacteria have developed resistance to β-lactams by two main mechanisms: the production of β-lactamases, sometimes accompanied by a decrease of outer membrane permeability, and the production of low-affinity, drug resistant Penicillin Binding Proteins (PBPs). PBPs remain attractive targets for developing new antibiotic agents because they catalyse the last steps of the biosynthesis of peptidoglycan, which is unique to bacteria, and lies outside the cytoplasmic membrane. Here we summarize the “current state of the art” of non-β-lactam inhibitors of PBPs, which have being developed in an attempt to counter the emergence of β-lactam resistance. These molecules are not susceptible to hydrolysis by β-lactamases and thus present a real alternative to β-lactams. We present transition state analogs such as boronic acids, which can covalently bind to the active serine residue in the catalytic site. Molecules containing ring structures different from the β-lactam-ring like lactivicin are able to acylate the active serine residue. High throughput screening methods, in combination with virtual screening methods and structure based design, have allowed the development of new molecules. Some of these novel inhibitors are active against major pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and thus open avenues new for the discovery of novel antibiotics. [less ▲]

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See detailDevelopment of new immunoassays for the quantification of inflammatory related cartilage degradation
Deberg, Michelle ULg; Christgau, Stephan; Cloos, Paul et al

in Osteoporosis International (2002, November), 13(Suppl. 3), 54

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See detailDevelopment of new immunoassays for the quantification of inflammatory related cartilage degradation
Deberg, Michelle ULg; Christgau, Stephan; Henriksen, Dennis et al

in Arthritis and Rheumatism (2002, September), 46(number 9 (suppl.)), 496

Detailed reference viewed: 7 (0 ULg)
See detailDevelopment of new strategies against the tomato leafminer, Tuta absoluta Meyrick
De Backer, Lara ULg; Francis, Frédéric ULg; Verheggen, François ULg

Conference given outside the academic context (2013)

The tomato leafminer, Tuta absoluta (Meyrick), is a Lepidoptera considered as one of the major pest of Solanaceae. It causes important yield loss in South America, where it is originated, and in the West ... [more ▼]

The tomato leafminer, Tuta absoluta (Meyrick), is a Lepidoptera considered as one of the major pest of Solanaceae. It causes important yield loss in South America, where it is originated, and in the West Palearctic region, where it was introduced in 2006. Insecticide applications and the use of the sexual pheromone have been the main control method used against T. absoluta. Insecticides are inefficient because of the endophytic habit of larvae, which are protected in the leaf mesophyll or inside fruits. Moreover, resistances against various insecticides have been reported. The sexual pheromone based strategies also provide poor results. One explanation has been recently provided by the demonstration of a parthenogenetic reproduction in T. absoluta, from the research group in Gembloux Agro-Bio Tech (ULg). Because there is a real need to improve crop protection against T. absoluta and in the meanwhile reducing the use of synthetic insecticidal compounds, researches aim at providing new perspectives to further biocontrol strategies against T. absoluta. [less ▲]

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See detailDevelopment of new thrombolytic agents using recombinant DNA technology.
Pierard, Luc ULg; Bollen, A.

in Journal of biotechnology (1990), 15(4), 283-304

The increasing incidence of thromboembolic diseases has sustained the search for new agents able to stimulate the natural fibrinolytic system. The first generation of antithrombotic agents include ... [more ▼]

The increasing incidence of thromboembolic diseases has sustained the search for new agents able to stimulate the natural fibrinolytic system. The first generation of antithrombotic agents include bacterial streptokinase and human urine urokinase. Because these molecules lack specificity for the fibrin clot, important efforts have been made to produce, using recombinant DNA technology, agents presenting higher fibrin clot selectivity such as t-PA (tissue-type plasminogen activator) and scu-PA (single chain urokinase-type plasminogen activator). In parallel, several laboratories are presently attempting to create mutants and hybrids plasminogen activators displaying improved thrombolytic properties with respect to the natural molecules. In this paper, we describe briefly the mechanisms of fibrinolysis and the role of the different natural thrombolytic agents. In addition, we review the possibilities of genetic engineering for the production of natural and novel plasminogen activators. [less ▲]

Detailed reference viewed: 12 (0 ULg)