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See detailChemo- and enantio-selective method for the analysis of amino acids by capillary electrophoresis with in-capillary derivatization.
Fradi, Ines ULg; Servais, Anne-Catherine ULg; Lamalle, Caroline ULg et al

in Journal of Chromatography. A (2012), 1267

A novel dual chiral CE method was developed for the separation of l- and d-amino acids (AAs), using in-capillary derivatization with 9-fluoroenylmethyl chloroformate (FMOC). Firstly, using pre-column ... [more ▼]

A novel dual chiral CE method was developed for the separation of l- and d-amino acids (AAs), using in-capillary derivatization with 9-fluoroenylmethyl chloroformate (FMOC). Firstly, using pre-column derivatization, the enantioseparation of FMOC-AAs was optimized according to the nature of cyclodextrins (CD). A background electrolyte (BGE) composed of 30mM beta-CD, 30mM octakis(2,3-dihydroxy-6-O-sulfo)-gamma-CD (OS-gamma-CD), 40mM tetraborate and 15% isopropanol (IPA) was selected and led to 17 baseline resolved pairs (R(s)=1.7-5.8) and two partially resolved pairs (Lys, R(s)=0.5 and Arg, R(s)=1.2). Experimental conditions for in-capillary derivatization were then optimized. Several parameters, such as mixing voltage and time, concentration of labeling solution and the length of the spacer plug were studied. The optimal conditions for in-capillary derivatization procedure were obtained using successive hydrodynamic injections (30mbar) of AAs for 2s, borate buffer for 4s and 10mM FMOC solution for 6s, followed by a mixing at 3kV for 72s and wait time of 1min. Moreover, a particular attention was paid to improve separation chemoselectivity. The effect on stereoselectivity and chemoselectivity of different factors, such as decrease of pH and tetraborate concentration and the addition of sodium dodecyl sulfate (SDS), was investigated using the in-capillary derivatization procedure. The best separation of a standard mixture of ten AA racemates was observed using a BGE containing 30mM beta-CD, 30mM OS-gamma-CD, 25mM SDS, 40mM sodium tetraborate and 17% IPA. [less ▲]

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See detailChemo-mechanical interactions in clay: a correlation between clay mineralogy and Atterberg limits
Schmitz, R. M.; Schroeder, Christian ULg; Charlier, Robert ULg

in Applied Clay Science (2004), 26(1-4), 351-358

Among some few others tests, the evaluation of the Atterberg limits is a very basic soil mechanical test allowing a first insight into the chemical reactivity of clays. Basically, the liquid limit and the ... [more ▼]

Among some few others tests, the evaluation of the Atterberg limits is a very basic soil mechanical test allowing a first insight into the chemical reactivity of clays. Basically, the liquid limit and the plasticity index are highly and mainly influenced by the ability of clay minerals to interact with liquids. In this contribution, a correlation between the Atterberg limits and clay mineralogy is proposed. This correlation increases the understanding between clay mineralogists and engineers in soil mechanics; additionally a wealth of information in clay mineralogy literature is now available to predict the mechanical behaviour of clays via index tests. (C) 2003 Elsevier B.V. All rights reserved. [less ▲]

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See detailChemo-mechanical interactions in clay: are the Atterberg limits useful?
Schmitz, R.; Hiligsmann, M.; Schroeder, Christian ULg et al

in Clays in Natural and Engineered Barriers of Radioactive Waste Confinement - Int. Meeting Reims (2002, December)

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See detailChemo-Mechanical Modelling of Soil or Rock Degradation
Charlier, Robert ULg; Boukpeti, N.

in 2nd Int. Symposium on Continuous and Discontinuous Modelling of Cohesive Frictional Materials. (2004, September)

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See detailCHEMOKINE (CC-MOTIF) LIGAND 2 AS A PROGNOSTIC SERUM MARKER IN CANINE IDIOPATHIC PULMONARY FIBROSIS
Roels, Elodie ULg; Holopainen, S.; Teske, Erik ULg et al

Poster (2015, September 11)

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See detailLes chémokines et leurs récepteurs : rôle dans les infections virales et dans les pathologies cancéreuses
Burteau, C.; Willems, Luc ULg; Kettmann, Richard ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2007)

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See detailChemometric tools for NIRS and NIR hyperspectral imaging
Dale, Laura ULg; Thewis, André ULg; Rotar, Ioan et al

in Bulletin of USAVM Cluj Napoca, Agriculture (2012, September 27), 69(1), 70-76

Nowadays in agriculture, new analytical tools based on spectroscopic technologies are developed. Near Infrared Spectroscopy (NIRS) is a well known technology in the agricultural sector allowing the ... [more ▼]

Nowadays in agriculture, new analytical tools based on spectroscopic technologies are developed. Near Infrared Spectroscopy (NIRS) is a well known technology in the agricultural sector allowing the acquisition of chemical information from the samples with a large number of advantages, such as: easy to use tool, fast and simultaneous analysis of several components, non-polluting, non-invasive and non destructive technology, and possibility of online or field implementation. Recently, NIRS system was combined with imaging technologies creating the Near Infrared Hyperspectral Imaging system (NIR-HSI). This technology provides simultaneously spectral and spatial information from an object. The main differences between NIR-HSI and NIRS is that many spectra can be recorded simultaneously from a large area of an object with the former while with NIRS only one spectrum was recorded for analysis on a small area. In this work, both technologies are presented with special focus on the main spectrum and images analysis methods. Several qualitative and quantitative applications of NIRS and NIR-HSI in agricultural products are listed. Developments of NIRS and NIR-HSI will enhance progress in the field of agriculture by providing high quality and safe agricultural products, better plant and grain selection techniques or compound feed industry’s productivity among others. [less ▲]

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See detailChemometrics and chromatographic fingerprints to discriminate and classify counterfeit medicines containing PDE-5 inhibitors.
Deconinck, Eric; Sacre, Pierre-Yves ULg; Courselle, Patricia et al

in Talanta (2012), 100

Chromatographic fingerprints recorded for a set of genuine and counterfeit samples of Viagra® and Cialis® were evaluated for their use in the detection and classification of counterfeit samples of these ... [more ▼]

Chromatographic fingerprints recorded for a set of genuine and counterfeit samples of Viagra® and Cialis® were evaluated for their use in the detection and classification of counterfeit samples of these groups of medicines. Therefore several exploratory chemometric techniques were applied to reveal structures in the data sets as well as differences among the samples. The focus was on the differentiation between genuine and counterfeit samples and on the differences between the samples of the different classes of counterfeits as defined by the Dutch National Institute for Public Health and the Environment (RIVM). In a second part the revealed differences between the samples were modelled to obtain a predictive model for both the differentiation between genuine and counterfeit samples as well as the classification of the counterfeit samples. The exploratory analysis clearly revealed differences in the data for the genuine and the counterfeit samples and with projection pursuit and hierarchical clustering differences among the different groups of counterfeits could be revealed, especially for the Viagra® data set. For both data sets predictive models were obtained with 100% correct classification rates for the differentiation between genuine and counterfeit medicines and high correct classification rates for the classification in the different classes of counterfeit medicines. For both data sets the best performing models were obtained with Least Square-Support Vector Machines (LS-SVM) and Soft Independent Modelling by Class Analogy (SIMCA). [less ▲]

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See detailChemometrics and vibrational spectroscopy for the detection of melamine levels in milk
Fernandez Pierna, Juan; Vincke, Damien; Baeten, Vincent et al

Poster (2016, January 19)

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See detailChemometrics methods for the identification and the monitoring of an odour in the environement with an electronic nose
Nicolas, Jacques ULg; Romain, Anne-Claude ULg; Maternova, J.

in Ramirez-Silva, Maria Theresa (Ed.) Sensors and chemometrics (2001)

The purpose of the paper is to briefly review some researches regarding the adaptation of the electronic nose principle to recognise some malodour sources in the environment, if possible directly in the ... [more ▼]

The purpose of the paper is to briefly review some researches regarding the adaptation of the electronic nose principle to recognise some malodour sources in the environment, if possible directly in the field, and to monitor the odour intensity continuously. Research aims at improving the portability and the user-friendliness of the instrument, together with testing what kind of signal may be used to monitor the odour. A laboratory-made electronic nose, constituted of an array of tin-oxide sensors, is used in different configurations. The ambient air is either sampled around environmental sources (landfill, urban waste composting facilities, …), or directly transferred into the sensor chamber in the field. Two main options are considered : firstly, identifying the source of odour in the background and among interfering odours and, secondly, when the malodour is recognised, trying to monitor it continuously in order, for example, to assess the nuisance or to control an odour abatement system. Chemometrics methods are generally used for both purposes. They provide quick answers and allow to evaluate the relationships between variables and between observations at a glance. They are applied on the sensor signals, eventually preprocessed by a suitable algorithm. Non-supervised analyses, such as Principal Component Analysis (PCA), provide basically a performance evaluation of the system during the development phase. On the contrary, supervised analyses, such as Discriminant Analysis (DA), or some Neural Networks algorithms are quite appropriate to make a reliable recognition in real time, when the system is developed. To predict the odour intensity, different techniques are tested : either using only one of the sensor elements, or applying different chemometrics techniques, such as Multilinear Regression (MLR) on the original measured sensor signals, Principal Component Regression (PCR), or Partial Least Squares regression (PLS). The latter seems to be the most adapted model for the intensity prediction. [less ▲]

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See detailChemoresistance to Valproate Treatment of Bovine Leukemia Virus-Infected Sheep; Identification of Improved HDAC Inhibitors
Gillet, Nicolas ULg; Vandermeers, Fabian ULg; De Brogniez, Alix ULg et al

in Pathogens (2012), (2012-1), 65-82

We previously proved that a histone deacetylase inhibitor (valproate, VPA) decreases the number of leukemic cells in bovine leukemia virus (BLV)-infected sheep. Here, we characterize the mechanisms ... [more ▼]

We previously proved that a histone deacetylase inhibitor (valproate, VPA) decreases the number of leukemic cells in bovine leukemia virus (BLV)-infected sheep. Here, we characterize the mechanisms initiated upon interruption of treatment. We observed that VPA treatment is followed by a decrease of the B cell counts and proviral loads (copies per blood volume). However, all sheep eventually relapsed after different periods of time and became refractory to further VPA treatment. Sheep remained persistently infected with BLV. B lymphocytes isolated throughout treatment and relapse were responsive to VPA-induced apoptosis in cell culture. B cell proliferation is only marginally affected by VPA ex vivo. Interestingly, in four out of five sheep, ex vivo viral expression was nearly undetectable at the time of relapse. In two sheep, a new tumoral clone arose, most likely revealing a selection process exerted by VPA in vivo. We conclude that the interruption of VPA treatment leads to the resurgence of the leukemia in BLV-infected sheep and hypothesize that resistance to further treatment might be due to the failure of viral expression induction. The development of more potent HDAC inhibitors and/or the combination with other compounds can overcome chemoresistance. These observations in the BLV model may be important for therapies against the related Human T-lymphotropic virus type 1. [less ▲]

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See detailA Chemoselective Ligation For The Synthesis Of Amino Acid Derivatives Of Virginiamycin M-1
Nott, Katherine ULg; Dufour, Samuel; Gossele, Francis et al

in Tetrahedron Letters (2005), 46(43),

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See detailChemotaxis-Promoting and Adhesion Properties of Human Tonsillar Follicular Dendritic Cell Clusters
Bouzahzah, F.; Antoine, Nadine ULg; Simar, Léon ULg et al

in Research in Immunology (1996), 147(3, Mar-Apr), 165-73

Lymph follicles are globular and compact due to aggregation of lymphoid cells on follicular dendritic cells (FDC). To probe the mechanisms underlying this accumulation of cells, we analyse here the role ... [more ▼]

Lymph follicles are globular and compact due to aggregation of lymphoid cells on follicular dendritic cells (FDC). To probe the mechanisms underlying this accumulation of cells, we analyse here the role played by FDCs in attracting and binding cells. FDCs prepared from human tonsils by mild separation techniques appeared in the form of clusters (FDC clusters), where, via cytoplasmic extensions, they enveloped lymphoid cells. Using Boyden's chambers, we demonstrated that these FDC clusters produced one or more chemoattractants capable of inducing chemotaxis of lymphoid cells. Supernatants of FDC cluster cultures also exerted a chemotaxis-promoting effect. FDC clusters induced true chemotaxis, not merely chemokinesis due to cell activation. They secreted a substance or substances that stuck to the substrate (a cellulose filter) and thus induced haptotaxis. B as well as T cells were attracted, but B cells apparently required the presence of T cells to respond fully to the chemoattractant(s). Subtypes of B cells (IgD+ and IgD-) and T cells (CD4+, CD8+, CD57+ AND CD57-) were tested and all were attracted. Since purified lymphoid cells did not induce these phenomena, FDCs were suspected to do so. FDCs have been shown to establish contact with lymphoid cells. Here we have determined that CD4+ T cells adhere in greater number to FDC clusters than do CD8+ T cells. We thus propose that FDCs specifically contribute to construction of lymph follicles by attracting and determining their cell composition. [less ▲]

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See detailChemotherapy options for patients suffering from heavily pretreated metastatic breast cancer.
Jerusalem, Guy ULg; RORIVE, Andrée ULg; COLLIGNON, Joëlle ULg

in Future oncology (London, England) (2015), 11(12), 1775-89

ABSTRACT The identification of additional chemotherapy agents for anthracycline- and taxane-pretreated advanced breast cancer (ABC) is an urgent medical need. Single agent chemotherapy is most times ... [more ▼]

ABSTRACT The identification of additional chemotherapy agents for anthracycline- and taxane-pretreated advanced breast cancer (ABC) is an urgent medical need. Single agent chemotherapy is most times administered because combined therapy is only associated with modest, if any, improvement in median progression-free survival. Randomized trials failed to show overall survival benefit compared with single agent chemotherapy. We hope to modify the natural history of ABC by the consecutive use of treatments with documented activity in heavily pretreated patients. Quality of life remains an important end point as cure is in general not possible. We first review the activity of the approved and the most frequently used agents in heavily pretreated ABC. Thereafter, the potential role and safety profile of etirinotecan pegol is discussed given the results recently released of a Phase III trial comparing this agent to Treatment of Physician's Choice. [less ▲]

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See detailChemotherapy-driven dysbiosis in the intestinal microbiome
Montassier, E.; Gastinne, T.; Vangay, P. et al

in Alimentary Pharmacology & Therapeutics (2015)

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See detailChemR23 dampens lung inflammation and enhances anti-viral immunity in a mouse model of acute viral pneumonia
Bondue, Benjamin; Vosters, Olivier; de Nadai, Patricia et al

in PLoS Pathogens (2011), 7(11), 1002358

Viral diseases of the respiratory tract, which include influenza pandemic, children acute bronchiolitis, and viral pneumonia of the elderly, represent major health problems. Plasmacytoid dendritic cells ... [more ▼]

Viral diseases of the respiratory tract, which include influenza pandemic, children acute bronchiolitis, and viral pneumonia of the elderly, represent major health problems. Plasmacytoid dendritic cells play an important role in anti-viral immunity, and these cells were recently shown to express ChemR23, the receptor for the chemoattractant protein chemerin, which is expressed by epithelial cells in the lung. Our aim was to determine the role played by the chemerin/ChemR23 system in the physiopathology of viral pneumonia, using the pneumonia virus of mice (PVM) as a model. Wild-type and ChemR23 knock-out mice were infected by PVM and followed for functional and inflammatory parameters. ChemR23(-/-) mice displayed higher mortality/morbidity, alteration of lung function, delayed viral clearance and increased neutrophilic infiltration. We demonstrated in these mice a lower recruitment of plasmacytoid dendritic cells and a reduction in type I interferon production. The role of plasmacytoid dendritic cells was further addressed by performing depletion and adoptive transfer experiments as well as by the generation of chimeric mice, demonstrating two opposite effects of the chemerin/ChemR23 system. First, the ChemR23-dependent recruitment of plasmacytoid dendritic cells contributes to adaptive immune responses and viral clearance, but also enhances the inflammatory response. Second, increased morbidity/mortality in ChemR23(-/-) mice is not due to defective plasmacytoid dendritic cells recruitment, but rather to the loss of an anti-inflammatory pathway involving ChemR23 expressed by non-leukocytic cells. The chemerin/ChemR23 system plays important roles in the physiopathology of viral pneumonia, and might therefore be considered as a therapeutic target for anti-viral and anti-inflammatory therapies. [less ▲]

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See detailUne chênaie n'est pas l'autre : analyse des contextes sylvicoles du chêne en forêt wallonne
Claessens, Hugues ULg; Perin, Jérôme ULg; Latte, Nicolas ULg et al

in Forêt Wallonne (2010), 108(sept-oct), 3-18

Le chêne n’est pas une essence facile à conduire vers la production de bois de qualité. Pour beaucoup d’entre eux, leur forme a été conditionnée il y a plus d’un siècle au sein de peuplements bien ... [more ▼]

Le chêne n’est pas une essence facile à conduire vers la production de bois de qualité. Pour beaucoup d’entre eux, leur forme a été conditionnée il y a plus d’un siècle au sein de peuplements bien différents de ce qu’ils sont devenus car originellement adaptés aux conditions socio-économiques qui prévalaient aux XIXe et au début du XXe siècle. Mais dans bien des cas, la sylviculture que l’on mène maintenant est encore sous la contrainte de ce passé. Cet article envisage les contextes « historico-sylvicoles » des chênaies de Wallonie à la lumière de leur état actuel. [less ▲]

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See detailLe chêne en forêt ardennaise, un atout à préserver
Alderweireld, Matthieu ULg; Ligot, Gauthier ULg; Latte, Nicolas ULg et al

in Forêt Wallonne (2010), 109(6), 10-24

Dans la forêt ardennaise, les chênes sont en nette diminution. Plusieurs facteurs sont responsables de cette diminution, voici quelques exemples : régénération plus difficile que le hêtre, abroutissement ... [more ▼]

Dans la forêt ardennaise, les chênes sont en nette diminution. Plusieurs facteurs sont responsables de cette diminution, voici quelques exemples : régénération plus difficile que le hêtre, abroutissement par le gibier, mauvaise réputation de la qualité du chêne ardennais dû aux anciens traitements, conditions de marché du bois défavorable aux essences à grandes révolution. Pourtant, ces dernières années, on prend conscience de leur importance. Les apports du chêne dans la hêtraie ardennaise sont nombreux, notamment dans le contexte du changement climatique : le chêne favorise le développement d’un cortège d’organismes diversifiés, favorise la décomposition de la litière et la fertilité des sols, permet l’exploitation des stations impropres au hêtre, favorise la stabilité des peuplements et permet la production de bois de qualité. Favoriser la régénération du chêne requiert une sylviculture interventionniste, les éléments principaux sont l’apport de lumière et la protection contre le gibier. Même s’il est possible de donner des pistes pour favoriser le chêne, de nombreuses questions se posent encore. Dans le contexte de l’Accord-cadre de recherche et vulgarisation forestières, l’ULg (GxABT) et l’UCL ont mis en place des dispositifs qui devraient bientôt permettre de mettre au point des scénarios sylvicoles. [less ▲]

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