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See detailChemical probes and signaling pathways for the orphan GPCR GPR27
Dupuis, Nadine ULg; Gilissen, Julie ULg; Pirotte, Bernard ULg et al

Poster (2013, January 28)

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See detailChemical processing for production of no-carrier-added selenium-73 from germanium and arsenic targets and synthesis of L-2-amino-4-([73Se]methylseleno) butyric acid (L-[73Se]selenomethionine).
Plenevaux, Alain ULg; Guillaume, Marcel; Brihaye, Claude et al

in International Journal of Radiation Applications and Instrumentation. Part A : Applied Radiation and Isotopes (1990), 41(9), 829-38

The Ge(4He, xn) and 75As(p, 3n) reactions were compared as the best potential routes for routine production of selenium-73 (73Se) for medical applications. With 26 MeV alpha particles, available with ... [more ▼]

The Ge(4He, xn) and 75As(p, 3n) reactions were compared as the best potential routes for routine production of selenium-73 (73Se) for medical applications. With 26 MeV alpha particles, available with compact cyclotrons, the first reaction required an enriched 70Ge target of sodium metagermanate to give a production yield of 1 mCi/microAh (0.037 GBq/microAh) in a 105 mg/cm2 target. With 55 MeV protons the As(p, 3n) reaction on natural arsenic yielded 20 mCi/microAh (0.74 GBq/microAh) in a 685 mg/cm2 target. A simple method was developed and optimized for both targets in order to isolate and purify the no-carrier-added selenium in the elemental form with a radiochemical yield greater than 75% in less than 90 min. An automated radiochemical processing unit has been designed for the routine production of 100-150 mCi (3.7-5.5 GBq) batches of carrier-free 73Se ready for radiopharmaceutical labeling. 30 mCi (1.11 GBq) (EOS) of L-2-amino-4-([73Se]methylseleno) butyric acid (L-[73Se]selenomethionine) ready for injection with a specific activity of 5 Ci/mmol (185 GBq/mmol) (EOS) were obtained through a fast chemical synthesis. Radiation absorbed dose estimates for L-[73Se]selenomethionine have been determined. A value of 0.70 rem/mCi (0.19 mSv/MBq) administered was calculated for the risk from irradiation in man. The first human PET investigation with [73Se]selenomethionine showed a very good delineation between liver and pancreas. [less ▲]

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See detailChemical processing for the production of carrier free selenium-73 from germanium and arsenic targets and synthesis of L-[73Se]selenomethionine.
Plenevaux, Alain ULg; Guillaume, M.; Brihaye, C. et al

in Journal of Labelled Compounds & Radiopharmaceuticals (1991), 30

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See detailChemical profiles in lake sediments in Laguna Chica de San Pedro (Bio-Bio Region, Chile)
Chirinos, L. R.; Urrutia, R.; Fagel, Nathalie ULg et al

in Journal of the Chilean Chemical Society [=JCCS] (2005), 50(4), 697-710

Metal profiles in lake sediments could provide historical environmental information on impacts caused by human activities and natural events, with view to the formulation of effective environmental ... [more ▼]

Metal profiles in lake sediments could provide historical environmental information on impacts caused by human activities and natural events, with view to the formulation of effective environmental policies. This paper presents data on sedimentary element profiles in Laguna Chica de San Pedro (LCSP) lake, located in the Bio Bio Region in Southern Chile, where important industrial activities are concentrated. Sediment properties (organic and inorganic matter, grain size, particle distribution, biogenic silica, Mn/ Fe ratio), major (Al, Ca, K, Mg, Ti, Na), trace (V, As, Co, Cu, Zn, Ni, Cr, Pb, Sr), and mobile (Fe, Mn, P, S) elements, as well as mineral profiles (plagioclase, quartz, clays, amorphous material) are presented, up to 65 cm depth. In general, relatively constant concentration profiles are observed in the sedimentary core middle section, for most elements. Most changes in composition are seen at the top (recent industrial period) and bottom (before human intervention) sections. Variable redox conditions, generated by biological activity at the sediment-water interface are likely to account for composition profiles at the sediment-water interface. On the other hand, physical processes seem to be mostly responsible for concentration changes in Pre-industrial sediments. Mineral content profiles, such as plagioclase, clay and quartz, as well as total clay content remain fairly constant in most of the core, showing significant changes at its bottom part. High excess V, As, and S values, especially at the upper sediment, arise as a consequence of redox conditions in the lake. Certainly, such metal enrichment is mainly associated with natural sedimentary matter supply from the watershed. [less ▲]

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See detailChemical profiles of Amblystegium riparium, Fontinalis antipyretica and Rhynchostegium riparioides in the Grand-Duchy of Luxembourg
Vanderpoorten, Alain ULg; Ector, L.; Hoffmann, L.

in Nova Hedwigia (2000), 71(1-2), 209-221

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See detailChemical properties of 11 date cultivars and their corresponding fibers extracts.
Borchani, C.; Besbes, Souhail; Blecker, Christophe ULg et al

in African Journal of Biotechnology (2010), 9(26), 4096-4105

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See detailA chemical proteomics approach for the identification of accessible antigens expressed in human kidney cancer
Castronovo, Vincenzo ULg; Waltregny, David ULg; Kischel, Philippe ULg et al

in Molecular & Cellular Proteomics (2006), 5(11), 2083-2091

A promising avenue toward the development of more selective anticancer drugs consists in the targeted delivery of bioactive molecules to the tumor environment by means of binding molecules specific to ... [more ▼]

A promising avenue toward the development of more selective anticancer drugs consists in the targeted delivery of bioactive molecules to the tumor environment by means of binding molecules specific to tumor-associated markers. We have used a chemical proteomics approach based on the ex vivo perfusion and biotinylation of accessible structures within surgically resected human kidneys with tumor to gain information about accessible and abundant antigens that are overexpressed in human cancer. This procedure led to the selective labeling with biotin of vascular structures. Biotinylated proteins were purified on streptavidin resin and identified using mass spectrometric methodologies, revealing 637 proteins, 184 of which were only found in tumor specimens and 223 of which were only found in portions of normal kidneys. Immunohistochemical and PCR analysis confirmed that several of the putative cancer antigens identified in this study are indeed preferentially expressed in tumors. In conclusion, we have developed a methodology that allows the identification of accessible biomarkers in human tissues. The tumor-associated antigens identified in this study may be suitable targets for antibody-based anticancer therapies. The experimental approach described here should be applicable to other surgical specimens and to other pathologies as well as to the study of basic physiological and immunological processes. [less ▲]

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See detailChemical reactions in an expanding fireball
Cugnon, Joseph ULg; Jaminon, Martine ULg

in Physics Letters B (1983), 123

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See detailChemical Reactions in the Cluster Ions of 1,1-Difluoroethene and Argon.
Güthe, F.; Jochims, H.-W.; Leyh, Bernard ULg et al

Book published by Berliner Elektronen Speicherring für Synchrotron Strahlung m.b.H (1995)

The preparation conditions of 1,1-difluoroethene-Ar clusters has been investigated by photoionization using synchrotron radiation. The nature of the products has been identified by a quadrupole mass ... [more ▼]

The preparation conditions of 1,1-difluoroethene-Ar clusters has been investigated by photoionization using synchrotron radiation. The nature of the products has been identified by a quadrupole mass spectrometer. [less ▲]

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See detailChemical Recognition of Antioxidants and UV-light Stabilizers on the Surface of Polypropylene : Atomic Force Microscopy with Chemically Modified Tips
Duwez, Anne-Sophie ULg; Poleunis, Claude; Bertrand, Patrick et al

in Langmuir (2001), 17

We show in this paper that it is possible to locally detect additives on the surface of polypropylene with chemically modified atomic force microscopy (AFM) tips. Gold-coated AFM tips modified with methyl ... [more ▼]

We show in this paper that it is possible to locally detect additives on the surface of polypropylene with chemically modified atomic force microscopy (AFM) tips. Gold-coated AFM tips modified with methyl and hydroxyl terminated self-assembled alkanethiol monolayers were used to measure adhesion forces on a process-stabilizing agent (Irgafos 168), an antioxidant (Irganox 1010), and UV-light stabilizers (Tinuvin 770, Dastib 845, Chimassorb 944, and Hostavin N30). Pull-off force measurements carried out on these pure additive films have shown that it is possible to discriminate between antioxidants and UV-light stabilizers. We have evidenced a characteristic fingerprint for each additive, according to the functionality of the tip used and themediumwherein the force measurements are realized (water or nitrogen atmosphere). Similarly we have measured pull-off forces on a melt-pressed polypropylene sample stabilized with Irgafos 168, Irganox 1010, and Tinuvin 770. These adhesion force measurements show that the extreme surface of the polymer is mainly made of a layer of Tinuvin 770. These results have been compared to those obtained from time-of-flight secondary ion mass spectrometry measurements [less ▲]

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See detailChemical soil factors influencing plant assemblages along copper-cobalt gradients: implications for conservation and restoration
Seleck, Maxime ULg; Bizoux, Jean-Philippe ULg; Colinet, Gilles ULg et al

in Plant and Soil (2013), 373

Aims Define the chemical factors structuring plant communities of three copper-cobalt outcrops (Tenke-Fungurume, Katangan Copperbelt, D. R. Congo) presenting extreme gradients. Methods To discriminate ... [more ▼]

Aims Define the chemical factors structuring plant communities of three copper-cobalt outcrops (Tenke-Fungurume, Katangan Copperbelt, D. R. Congo) presenting extreme gradients. Methods To discriminate plant communities, 172 vegetation records of all species percentage cover were classified based on NMDS and the Calinski criterion. Soil samples were analyzed for 13 chemical factors and means compared among communities with ANOVA. Partial canonical correspondence analysis (pCCA) was used to determine amount of variation explained individually by each factor and site effect. Results Seven communities were identified. Six of the studied communities were related to distinct sites. Site effect (6.0 % of global inertia) was identified as the most important factor related to plant communities’ variation followed by Cu (5.5 %), pH (3.6 %) and Co (3.5 %). Unique contribution of site effect (3.8 %) was higher than that of Cu (1.1 %) and Co (1.0 %). Conclusions In restoration, not only Cu and Co contents will be important to maintain vegetation diversity, attention should also be given to co-varying factors potentially limiting toxicity of metals: pH, organic matter, Ca and Mn. Physical parameters were also identified as important in the creation of adequate conditions for diverse communities. Further studies should focus on the effect of physical parameters and geology. [less ▲]

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See detailChemical spots and their dynamical evolution on HgMn stars
Korhonen, Heidi; Hubrig, Swetlana; Briquet, Maryline ULg et al

in The Physics of Sun and Star Spots, Proceedings of the International Astronomical Union, IAU Symposium, Volume 273 (2011, August 01)

Our recent studies of late B-type stars with HgMn peculiarity revealed for the first time the presence of fast dynamical evolution of chemical spots on their surfaces. These observations suggest a ... [more ▼]

Our recent studies of late B-type stars with HgMn peculiarity revealed for the first time the presence of fast dynamical evolution of chemical spots on their surfaces. These observations suggest a hitherto unknown physical process operating in the stars with radiative outer envelopes. Furthermore, we have also discovered existence of magnetic fields on these stars that have up to now been thought to be non-magnetic. Here we will discuss the dynamical spot evolution on HD 11753 and our new results on magnetic fields on AR Aur. [less ▲]

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See detailChemical Structure and Pharmacological (Curarizing) Properties of Various Indole Alkaloids Extracted from an African Strychnos
Angenot, Luc ULg; Dubois, Michel; Ginion, Ch. et al

in Archives Internationales de Pharmacodynamie et de Thérapie (1975), 215(2), 246-258

The chemical separation and identification of ten alkaloids extracted from the roots of Strychnos usambarensis are described. The elucidation of their structure by means of elementary analysis, IR, UV and ... [more ▼]

The chemical separation and identification of ten alkaloids extracted from the roots of Strychnos usambarensis are described. The elucidation of their structure by means of elementary analysis, IR, UV and mass spectrometry allows their classification into bistertiary amines, hybrid and bisquaternary ammonium derivatives. This classification is reflected in the pharmacological properties. One of the tertiary amine alkaloids (usambarensine) presents atropine-like and spasmolytic activities while the bisquaternary ammonium compounds ( dihydrotoxiferine, C-curarine, calebassine and afrocurarine) are competitive neuromuscular blocking agents. [less ▲]

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See detailChemical structure of the cell wall of Mycobacterium smegmatis. I. Isolation and partial characterization of the peptidoglycan
Petit, J. F.; Adam, A.; Wietzerbin-Falszpan, J. et al

in Biochemical & Biophysical Research Communications (1969), 35(4), 478-485

Cell walls of were prepared by French press disruption and treatment with trypsin and chymotrypsin. Free lipids were extracted by organic solvents. Part of the bound lipids were solubilized by an alkaline ... [more ▼]

Cell walls of were prepared by French press disruption and treatment with trypsin and chymotrypsin. Free lipids were extracted by organic solvents. Part of the bound lipids were solubilized by an alkaline treatment and most of the remaining lipids and neutral sugars by mild acid hydrolysis, leaving an insoluble residue which has the composition of a peptidoglycan. This residue was solubilized by AL1 enzyme. It was possible to isolate from the lysate a tripeptide Ala-Glu-DAP, three tetrapeptides Ala-Glu-DAP-Ala and also a tetrasaccharide and a disaccharide which give equimolar amounts of glucosamine and muramic acid after acid hydrolysis. The disaccharide differs from the typical [beta]-1,4-N-acetylglucosaminyl-N-acetylmuramic acid by its Rf values in various solvents. [less ▲]

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See detailChemical surface inhomogeneities in late B-type stars with Hg and Mn peculiarity: I. Spot evolution in HD 11753 on short and long time scales
Korhonen, Heidi; Gonzalez, J.F.; Briquet, Maryline ULg et al

in Astronomy and Astrophysics (2013), 553

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See detailChemically resistant encapsulant to enable a novel MEMS fabrication process
Stoukatch, Serguei ULg; Walewyns, Thomas; Tooten, Ester et al

in Conf. Proceedings (2013, June 13)

We have proposed and demonstrated a novel sequence in MEMS fabrication process flow. The novel MEMS fabrication process flow can be shortly described as a “packaging first, MEMS release second”, whereas a ... [more ▼]

We have proposed and demonstrated a novel sequence in MEMS fabrication process flow. The novel MEMS fabrication process flow can be shortly described as a “packaging first, MEMS release second”, whereas a standard process starts form MEMS release and ends up with packaging. The process is explored on a 3D capacitive MEMS sensor (3 x 3 mm²). Unreleased wafer is singulated by sawing on individual dies, then the individual sensor is mounted to the package, wire bonded and encapsulated. Because the sensors are still unreleased there is no damage occurred during the assembly. However the choice for the encapsulant material is not evident. The encapsulant must survive the chemical attack during the MEMS release process (mixture of 73%HF and IPA (isopropanol)), followed by a triple rinse in IPA. We pre-selected 6 different encapsulants: a silicone-, an epoxy- and an urethane-based. At least one encapsulant passed the acceptance criteria: there is no delamination, there is no texture change and the encapsulant maintains a sufficient mechanical adhesion. Additionally to that we measured micro-hardness of the encapsulant before and after the HF release test. We also performed an electrical characterization of the flow meter sensor before and after the HF release and we detected no changes in the sensor’s performance caused by HF exposure. We have proposed and demonstrated a novel sequence for MEMS fabrication. We packaged the sensor first, and performed the release after that. The key enabler for the novel process is the encapsulant which can withstand exposure to the release solution (73%HF:IPA). [less ▲]

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See detailChemically resistant encapsulation for MEMS release
Stoukatch, Serguei ULg; Tooten, ester; Axisa, Fabrice ULg et al

Conference (2012, March 21)

We have proposed and explored a novel sequence in MEMS fabrication process flow. The novel MEMS fabrication process flow can be shortly described as a “packaging first, MEMS release second”. We propose to ... [more ▼]

We have proposed and explored a novel sequence in MEMS fabrication process flow. The novel MEMS fabrication process flow can be shortly described as a “packaging first, MEMS release second”. We propose to package the MEMS device first (die mount, wire bonding and encapsulation) and to perform the MEMS release as the last step in the fabrication process flow. The standard route for IC manufacturing is, that the die packaging is the last step [1]. Such approach can’t be directly transferred and used for MEMS fabrication [2]. The main reason for that, that the MEMS device after the release becomes vulnerable to any physical and chemical exposure. Such exposure can occur during transportation, handling or any post-processing (incl. the packaging). [less ▲]

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See detailChemically selected subclones of the CEM cell line demonstrate resistance to HIV-1 infection resulting from a selective loss of NF-kappa B DNA binding proteins.
Qian, J.; Bours, Vincent ULg; Manischewitz, J. et al

in Journal of Immunology (1994), 152(8), 4183-91

To delineate cellular genes that are required for optimal HIV-1 infection, CEM cells were subjected to treatment with the chemical mutagen ethylmethanesulfonate (EMS) and subclones were selected based on ... [more ▼]

To delineate cellular genes that are required for optimal HIV-1 infection, CEM cells were subjected to treatment with the chemical mutagen ethylmethanesulfonate (EMS) and subclones were selected based on their increased resistance to HIV-1 infection and reduced syncytium formation, despite relatively normal CD4 expression (20,000 to 25,000 receptors/cell). Two subclones with this phenotype demonstrated a diminished capacity of HIV-1 long terminal repeat-chloramphenicol acetyl transferase expression either after treatment with the protein kinase C activator PMA, or through Tat-mediated transactivation. In this study, we show that the cellular levels of the NF-kappa B DNA binding proteins (but not AP1 or SP1) are markedly reduced in these cell mutants both at the mRNA and protein levels, resulting in reduced nuclear localization of p50/p65 after PMA induction or treatment with the lymphokine TNF-alpha. Transient reconstitution with a plasmid expressing p50 resulted in partial recovery of PMA-inducible LTR-chloramphenicol acetyl transferase expression. These data suggest that, at least in the CEM T cell line, a selective reduction in the NF-kappa B DNA binding proteins is sufficient to curtail HIV-1 infection. [less ▲]

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