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See detailCombination of ring-opening polymerization and "click" chemistry for the synthesis of an amphiphilic tadpole-shaped poly(epsilon-caprolactone) grafted by PEO
Li, Haiying; Riva, Raphaël ULg; Jérôme, Robert ULg et al

in Macromolecules (2007), 40(4), 824-831

A tadpole shaped poly(epsilon-caprolactone) (PCL; Mn = 24 500) was made amphiphilic by grafting the two PCL tails with PEO. In the first step, a macrocyclic PCL was synthesized by ring-opening ... [more ▼]

A tadpole shaped poly(epsilon-caprolactone) (PCL; Mn = 24 500) was made amphiphilic by grafting the two PCL tails with PEO. In the first step, a macrocyclic PCL was synthesized by ring-opening polymerization of epsilon-caprolactone (epsilon-CL) initiated by a cyclic tin(IV) dialkoxide and stabilized by local intramolecular photo-cross-linking. In the second step, the polymerization of a mixture of epsilon CL and alpha-chloro-epsilon-caprolactone (alpha Cl epsilon CL) was resumed with formation of two activated chloride containing PCL tails. In the third step, the chlorides were converted into azides onto which alkynyl end-capped PEO was grafted by the copper-mediated Huisgen's cycloaddition [3 + 2], thus giving a "click" reaction. The thermal properties of the final copolymer and the precursors were analyzed by differential scanning calorimetry. The amphiphilicity of the final copolymer was confirmed by micellization in water. [less ▲]

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See detailCombination of ring-opening polymerization and "click" chemistry towards functionalization of aliphatic polyesters
Riva, Raphaël ULg; Schmeits, Stephanie ULg; Stoffelbach, François et al

in Chemical Communications (2005), (42), 5334-5336

Azide pendent groups of aliphatic polyesters have been derivatized into tertiary amines, ammonium salts and poly(ethylene oxide) grafts. The experimental conditions have been optimized (organic solvent ... [more ▼]

Azide pendent groups of aliphatic polyesters have been derivatized into tertiary amines, ammonium salts and poly(ethylene oxide) grafts. The experimental conditions have been optimized (organic solvent, 35 degrees C), such that the aliphatic polyesters are not degraded, including even poly(lactide) which is very sensitive to attack by weak nucleophiles. [less ▲]

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See detailCombination of trophic biomarkers to distinguish among Antarctic amphipods trophic guilds
Nyssen, Fabienne ULg; Dauby, Patrick ULg; Graeve, Martin

Conference (2004, July)

Peracarid crustaceans and amphipods in particular are an important group in the Southern Ocean and one of the most diverse in the macrozoobenthos. As a part of a multidisciplinary study of the amphipods ... [more ▼]

Peracarid crustaceans and amphipods in particular are an important group in the Southern Ocean and one of the most diverse in the macrozoobenthos. As a part of a multidisciplinary study of the amphipods ecological roles in Antarctic benthic systems, about 150 specimens belonging to 25 species of 10 of the most common amphipod families occurring in the Southern Ocean have been involved in this study of amphipod trophic patterns. Beside “classical” stomach content analysis or field observations, the use of naturally occurring stable isotopes of carbon (δ13C) and nitrogen (δ15N) has recently provided new insights into food web ecology. This method is based on the direct relationship established between the isotopic signature of an organism and that of its preys. Nitrogen-15 typically shows a step-wise increase with trophic level within a food chain. Closer to the value of the diet, carbon-13 is preferentially used to assess the relative proportion of potential primary sources in a trophic web (ex.: pelagic vs benthic contribution to food intake). Furthermore, for several species, the lipid signature – which has already been used successfully to help understand marine trophodynamics – and more particularly the fatty acid composition has been investigated as trophic biomarkers to reveal more precisely to which trophic guild they belong to. [less ▲]

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See detailCombination therapy versus monotherapy: a randomised pilot study on the evolution of inflammatory parameters after ventilator associated pneumonia
Damas, Pierre ULg; Garweg, Christophe ULg; Monchi, Mehran et al

in Critical Care (2006), 10(2), 52

Introduction Combination antibiotic therapy for ventilator associated pneumonia (VAP) is often used to broaden the spectrum of activity of empirical treatment. The relevance of such synergy is commonly ... [more ▼]

Introduction Combination antibiotic therapy for ventilator associated pneumonia (VAP) is often used to broaden the spectrum of activity of empirical treatment. The relevance of such synergy is commonly supposed but poorly supported. The aim of the present study was to compare the clinical outcome and the course of biological variables in patients treated for a VAP, using a monotherapy with a beta-lactam versus a combination therapy. Methods Patients with VAP were prospectively randomised to receive either cefepime alone or cefepime in association with amikacin or levofloxacin. Clinical and inflammatory parameters were measured on the day of inclusion and thereafter. Results Seventy-four mechanically ventilated patients meeting clinical criteria for VAP were enrolled in the study. VAP was microbiologically confirmed in 59 patients (84%). Patients were randomised to receive cefepime (C group, 20 patients), cefepime with amikacin (C-A group, 19 patients) or cefepime with levofloxacin (C-L group, 20 patients). No significant difference was observed regarding the time course of temperature, leukocytosis or C-reactive protein level. There were no differences between length of stay in the intensive care unit after infection, nor in ventilator free days within 28 days after infection. No difference in mortality was observed. Conclusion Antibiotic combination using a fourth generation cephalosporin with either an aminoside or a fluoroquinolone is not associated with a clinical or biological benefit when compared to cephalosporin monotherapy against common susceptible pathogens causing VAP. [less ▲]

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See detailCombination/Sequential Therapy in Osteoporosis
Lecart, Marie-Paule; Bruyère, Olivier ULg; Reginster, Jean-Yves ULg

in Current Osteoporosis Reports (2004), 2(4), 123-30

Combination therapy includes the concomitant or sequential use of compounds sharing the same mode of action (eg, two or more inhibitors of bone resorption) or with distinct pathways of activity (eg, an ... [more ▼]

Combination therapy includes the concomitant or sequential use of compounds sharing the same mode of action (eg, two or more inhibitors of bone resorption) or with distinct pathways of activity (eg, an inhibitor of resorption plus an anabolic agent). Combination use of antiresorptive agents may generate concerns, because of the risk of inducing oversuppression of bone turnover. However, if low doses of estrogen, used for the management of climacteric symptoms, are insufficient to normalize bone turnover, the addition of a bisphosphonate to hormone therapy may prove to be useful to achieve this objective. Patients pretreated with inhibitors of resorption, who have not achieved a full therapeutic response, are good candidates for treatment with anabolic agents. The increase in bone turnover that comes after the introduction of parathyroid hormone (PTH) in patients treated with an antiresorptive agent is similar to that observed in treatment-naive patients and the pattern of bone mineral density (BMD) increase is also identical, with the exception of a 6 month delay in the spine and hip BMD changes observed in prior alendronate-treated subjects. Current data discourage the concomitant use of alendronate and PTH since the bisphosphonate appears to blunt (in men and women) the anabolic action of PTH. Whether this applies to other bisphosphonates or inhibitors of resorption, remains unknown. The use of an inhibitor of bone resorption after completion of PTH treatment seems an appropriate way to maintain the skeletal benefits gained during therapy. Long-term clinical studies, using fractures as an endpoint should be initiated to better understand the clinical and pharmaco-economic interest of combination therapies in the management of osteoporosis. [less ▲]

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See detailA combinatorial branch-and-bound algorithm for box search
Mathieu, Sébastien ULg; Louveaux, Quentin ULg

in Discrete Optimization (2014), 13

Considering a set of points in a multi-dimensional space with an associated real value for each point, we want to find the box with the maximum sum of the values of the included points. This problem has ... [more ▼]

Considering a set of points in a multi-dimensional space with an associated real value for each point, we want to find the box with the maximum sum of the values of the included points. This problem has applications in data mining and can be formulated as a mixed-integer linear program. We propose a branch-and-bound algorithm where the bounding is obtained by combinatorial arguments instead of the traditional linear relaxation. Computational experiments show that this approach competes with current state of the art mixed-integer solvers. The algorithm proposed in this paper may be seen as a simple and dependence-free method to solve the box search problem. [less ▲]

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See detailCombinatorial optimization approaches to the design of load shedding schemes against voltage instability
Moors, Cédric; Lefebvre, Daniel; Van Cutsem, Thierry ULg

(2000, October)

This paper proposes a methodology for the design of automatic load shedding against long-term voltage instability. In a first step, a set of training scenarios is set up, corresponding to various ... [more ▼]

This paper proposes a methodology for the design of automatic load shedding against long-term voltage instability. In a first step, a set of training scenarios is set up, corresponding to various operating conditions and disturbances. Each scenario is analyzed to determine the minimal load shedding which stabilizes the system, with due consideration for the shedding location and delay. In a second step, the parameters of a closed-loop undervoltage load shedding scheme are determined so as to: (i) approach as closely as possible the optimal sheddings computed in the first step, over the whole set of scenarios; (ii) stabilize the system in all the unstable scenarios and (iii) shed no load in the stable ones. The corresponding optimization problem is solved using three methods : genetic algorithms, branch and bound approach and the so-called “sequential design”. A detailed example is given on the Hydro-Qu´ebec system in which load shedding is presently planned. [less ▲]

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See detailCombinatorial Optimization Models in Automated Manufacturing
Crama, Yves ULg

Conference (2010, April 01)

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See detailA combinatorial proof of $S$-adicity for sequences with linear complexity
Leroy, Julien ULg; Richomme, Gwenaël

in Integers: Electronic Journal of Combinatorial Number Theory (2013), 13

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See detailCombinatorics, Automata and Number Theory 2006
Berthé, Valérie; Lecomte, Pierre ULg; Rigo, Michel ULg

in Theoretical Computer Science (2008), 391

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See detailCombine pedigree and marker information into a single estimator for the calculation of relationships
Bömcke, Elisabeth ULg; Gengler, Nicolas ULg

Poster (2009, May)

Relationship coefficients are particularly useful to improve genetic management of endangered populations. Estimation of relationships was traditionally based on pedigree data but, today, numerous methods ... [more ▼]

Relationship coefficients are particularly useful to improve genetic management of endangered populations. Estimation of relationships was traditionally based on pedigree data but, today, numerous methods already exist to replace pedigrees by molecular data. However, genotyping a complete population for a sufficient number of markers can be impossible, e.g., in case of local and/or rare breeds. The idea was therefore to develop a new method to estimate relationship by combining molecular with pedigree data into a single estimator. Originally developed for the management of an endangered horse population, it will be useful for specific situations, where neither pedigree nor molecular data are complete. Two questions appeared: What and how to combine? Following the principle that things have to be similar to be combined, we compared two coefficients that have the advantage to be similarly defined: the additive relationship coefficient (axy) calculated from pedigrees and the total allelic relationship (taxy) obtained from markers. Wright relationship coefficient (rped,xy) were also compared to taxy, transformed into rmol,xy, to highlight the influence of inbreeding. The results showed the influence of inbreeding, of marker quality and the tendency of molecular coefficients to overestimate the relationship among individuals. The method to combine the selected coefficients was also determined. Various parameters were taken into account in the model: number of markers and quality (e.g. marker informativeness), mutation rate, pedigree quality (e.g. generation-equivalents), … The combined estimator has several advantages. Especially, negative relationship values obtained in literature with molecular-based estimators in case of small inbred populations can be avoided. [less ▲]

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See detailCombined (hormonal and microsurgical) therapy in infertile women with endometriosis.
Donnez, J.; Lemaire-Rubbers, M.; Karaman, Y. et al

in Fertility and Sterility (1987), 48(2), 239-42

Fifty patients with moderate or severe endometriosis received 5 mg/day lynestrenol for 6 months prior to microsurgery. A significant regression of the ovarian and peritoneal implants was observed in 72 ... [more ▼]

Fifty patients with moderate or severe endometriosis received 5 mg/day lynestrenol for 6 months prior to microsurgery. A significant regression of the ovarian and peritoneal implants was observed in 72% of the cases after progestative treatment, but the presence of residual epithelium in all cases made surgical resection necessary. After preoperative medical treatment and microsurgery, intrauterine (living births) pregnancy rates of 60 and 47% were obtained in cases of moderate and severe endometriosis, respectively. The following prognostic factors were found in this series: the degree of endometriosis, the concomitant male factors, the decrease of endometriotic lesions after treatment, and the unilaterality of ovarian endometriosis. [less ▲]

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See detailCombined 10pter-->P11 and 18pter-->Q11 Trisomy in a 7-Year-Old Child
Lapiere, J. C.; Verloes, Alain ULg; Herens, Christian ULg et al

in Genetic Counseling (Geneva, Switzerland) (1992), 3(3), 155-9

We report a severely mentally retarded, dysmorphic girl aged 7 years with a 47,XX, +der(18), t(10;18)(p11.2;q11.2)mat. The phenotype of our patient is compared with 6 cases of trisomy 10p and 10 cases of ... [more ▼]

We report a severely mentally retarded, dysmorphic girl aged 7 years with a 47,XX, +der(18), t(10;18)(p11.2;q11.2)mat. The phenotype of our patient is compared with 6 cases of trisomy 10p and 10 cases of trisomy 18q- from the literature. The short trisomic segment 10pter-10p11 appears to affect more the phenotype than the trisomic segment 18qter-q11. [less ▲]

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See detailCombined action of diazepam and d-amphetamine on fixed-interval performance in cats
Richelle, Marc ULg

in Journal of the Experimental Analysis of Behavior (1969), 12(6), 989-998

Cats trained under a fixed-interval 5-min schedule of milk presentation were injected with diazepam, amphetamine, and combinations of amphetamine and diazepam. Diazepam increased overall reponse rate as a ... [more ▼]

Cats trained under a fixed-interval 5-min schedule of milk presentation were injected with diazepam, amphetamine, and combinations of amphetamine and diazepam. Diazepam increased overall reponse rate as a function of the dose and disrupted the temporal pattern of responding. Low doses of amphetamine (0.5mg/kg) usually increased the response rate; higher doses (1 to 2 mg/kg) either decreased the response rate or had little effect. Amphetamine always disrupted the temporal pattern of responding, even though it did not affect the overall rate. When doses of amphetamine that increased the response rate or left it unchanged were combined with diazepam, a potential increase in response rate occured. When doses of amphetamine that decreased the response rate were combined with diazepam, the amphetamine-induced rate decreases were reversed at least partially. Less clear potentiation of disruption of the temporal pattern of responding was observed when amphetamine and diazepam were combined. [less ▲]

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See detailCombined analysis from eleven linkage studies of bipolar disorder provides strong evidence of susceptibility loci on chromosomes 6q and 8q
McQueen, M. B.; Devlin, B.; Faraone, S. V. et al

in American Journal of Human Genetics (2005), 77(4), 582-95

Several independent studies and meta-analyses aimed at identifying genomic regions linked to bipolar disorder (BP) have failed to find clear and consistent evidence of linkage regions. Our hypothesis is ... [more ▼]

Several independent studies and meta-analyses aimed at identifying genomic regions linked to bipolar disorder (BP) have failed to find clear and consistent evidence of linkage regions. Our hypothesis is that combining the original genotype data provides benefits of increased power and control over sources of heterogeneity that outweigh the difficulty and potential pitfalls of the implementation. We conducted a combined analysis using the original genotype data from 11 BP genomewide linkage scans comprising 5,179 individuals from 1,067 families. Heterogeneity among studies was minimized in our analyses by using uniform methods of analysis and a common, standardized marker map and was assessed using novel methods developed for meta-analysis of genome scans. To date, this collaboration is the largest and most comprehensive analysis of linkage samples involving a psychiatric disorder. We demonstrate that combining original genome-scan data is a powerful approach for the elucidation of linkage regions underlying complex disease. Our results establish genomewide significant linkage to BP on chromosomes 6q and 8q, which provides solid information to guide future gene-finding efforts that rely on fine-mapping and association approaches. [less ▲]

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See detailCombined analysis of fourteen nuclear genes refines the Ursidae phylogeny
Pagès, Marie ULg; Calvignac, Sébastien; Klein, Catherine et al

Poster (2007, August)

To definitively solve the last the ambiguities concerning the evolutionary history of Ursidae, we sequenced ten nuclear genes for all the eight extant bear species. By combining these new sequences with ... [more ▼]

To definitively solve the last the ambiguities concerning the evolutionary history of Ursidae, we sequenced ten nuclear genes for all the eight extant bear species. By combining these new sequences with those of four other recently published nuclear markers, we provide new insights into the phylogenetic relationships of the Ursidae family members. The hypothesis that the giant panda was the first species to diverge among ursids is definitively confirmed and the branching order within the Ursus genus is clarified for the first time. Moreover, these analyses indicate that the American and the Asiatic black bears do not cluster as sister taxa, as had been previously hypothesised. Sun and sloth bears undoubtedly appear as the most basal ursine species but uncertainties about their exact relationships remain. [less ▲]

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See detailCombined analysis of fourteen nuclear genes refines the Ursidae phylogeny
Pagès, Marie ULg; Calvignac, Sébastien; Klein, Catherine et al

in Molecular Phylogenetics & Evolution (2008), 47

Despite numerous studies, questions remain about the evolutionary history of Ursidae and additional independent genetic markers were needed to elucidate these ambiguities. For this purpose, we sequenced ... [more ▼]

Despite numerous studies, questions remain about the evolutionary history of Ursidae and additional independent genetic markers were needed to elucidate these ambiguities. For this purpose, we sequenced ten nuclear genes for all the eight extant bear species. By combining these new sequences with those of four other recently published nuclear markers, we provide new insights into the phylogenetic relationships of the Ursidae family members. The hypothesis that the giant panda was the first species to diverge among ursids is definitively confirmed and the precise branching order within the Ursus genus is clarified for the first time. Moreover, our analyses indicate that the American and the Asiatic black bears do not cluster as sister taxa, as had been previously hypothesised. Sun and sloth bears clearly appear as the most basal ursine species but uncertainties about their exact relationships remain. Since our larger dataset did not enable us to clarify this last question, identifying rare genomic changes in bear genomes could be a promising solution for further studies. [less ▲]

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See detailCombined analysis of HPV DNA, p16, p21 and p53 to predict prognosis in patients with stage IV hypopharyngeal carcinoma.
Ernoux-Neufcoeur, P.; Arafa, M.; Decaestecker, C. et al

in Journal of Cancer Research & Clinical Oncology (2011), 137(1), 173-81

PURPOSE: We examined p16, p21 and p53 expression in combination with the presence of human papillomavirus (HPV) DNA as molecular markers to predict survival in patients with stage IV hypopharyngeal ... [more ▼]

PURPOSE: We examined p16, p21 and p53 expression in combination with the presence of human papillomavirus (HPV) DNA as molecular markers to predict survival in patients with stage IV hypopharyngeal squamous cell carcinoma (HSCC). METHODS: Paraffin-embedded tumours from HSCC patients (n = 75) were evaluated for p16, p21 and p53 expression by immunohistochemistry. HPV DNA was detected by GP5+/6+ consensus PCR and subsequent genotyping by E6/E7 type-specific PCR for HPV types 6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66 and 68. RESULTS: Among the 61 specimens that tested positive for the beta-globin, HPV typing identified 50 patients with high-risk (hr) HPV types. HPV 16E7 DNA was detected in 74% (37 cases) of these specimens. Twelve patients were found to be infected with multiple HPV types. However, the presence of hrHPV DNA was not found to correlate with the proportion of disease-free patients. The 5-year disease-free survival rate was 73% in p53- tumours versus 48% in p53+ tumours (P = 0.008). CONCLUSION: In our series of patients with stage IV HSCC, the hrHPV+ subgroup had a similar prognosis (in terms of recurrence risk) as the HPV- subgroup. p53 overexpression was associated with a worse prognosis. [less ▲]

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See detailThe combined bone forming capacity of human periosteal derived cells and calcium phosphates.
Roberts, Scott J; Geris, Liesbet ULg; Kerckhofs, Greet ULg et al

in Biomaterials (2011), 32(19), 4393-405

Current knowledge suggests that the periosteum, a fibrous tissue which covers the surface of all bones, contains a population of progenitor cells which mediate the repair of bone defects. In an effort to ... [more ▼]

Current knowledge suggests that the periosteum, a fibrous tissue which covers the surface of all bones, contains a population of progenitor cells which mediate the repair of bone defects. In an effort to optimise the utilisation of this source of cells for bone engineering, herein we describe the rational selection of calcium phosphate (CaP) containing materials, based on biomaterial properties, and evaluation of their combined bone forming capacity. Five different commercially available orthopaedic 3D matrices composed of CaP particles in an open collagen network (NuOss, CopiOs, Bio-Oss((R)), Collagraft and Vitoss((R))) were evaluated in vitro and in vivo with human periosteal derived cells (hPDCs). It was found that the cell-material combinations behaved quite differently in vivo, despite apparent in vitro similarities in gene expression profiles. Bone formation was highest within the NuOss/hPDC implant at 13.03%, which also contained the highest incidence of bone marrow formation. The bone formed in this implant was chimeric with approximately 65% originating from implanted cells. Upon analysis of human specific gene expression, although it was found that predominantly osteogenic differentiation was observed within NuOss/hPDC implants, a lesser induction of chondrogenic genes was also observed. The formation of a cartilage intermediate was confirmed by histology. Additionally the NuOss/hPDC implant integrated into the mouse environment with apparent active scaffold resorption. This study demonstrates the importance of matching a cell support/biological matrix with a cell type and subsequently has outlined parameters which can be used for the rational selection of biomaterials for bone engineering. [less ▲]

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See detailCombined detailed and quasi steady-state time simulations for large-disturbance analysis
Van Cutsem, Thierry ULg; Grenier, Marie-Eve; Lefebvre, Daniel

in International Journal of Electrical Power & Energy Systems (2006), 28(9), 634-642

This paper deals with the simulation of long-term responses of power systems to large disturbances in the presence of discrete events. After outlining the power system model under the quasi steady-state ... [more ▼]

This paper deals with the simulation of long-term responses of power systems to large disturbances in the presence of discrete events. After outlining the power system model under the quasi steady-state (QSS) approximation, a method combining detailed and QSS time simulations is presented, the former being used for accuracy and the latter for efficiency reasons. Detailed time simulation is used to analyze the short-term period following a large disturbance and identify the discrete controls triggered. Next, QSS simulation is used to simulate the same time interval with the discrete controls imposed as external events, before letting the system evolve as usual in the long-term. This simple method has been successfully tested on the Hydro-Quebec system. (C) 2006 Elsevier Ltd. All rights reserved. [less ▲]

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