A comprehensive review of C-S-H empirical and computational models, their applications, and practical aspects

[EN] The C-S-H gel is an elusive material. Its variable composition and disordered nature complicate a complete characterization of its atomic structure, and the elaboration of models is key to understanding it. This work aims to review those proposed models, dividing them into empirical and computational models. After a brief description of related crystalline calcium silicate hydrates, empirical C-S-H models based on interpretation of experimental data are presented. Then, we focus on the historic development of atomistic models to study the C-S-H, until the current state of the art. We describe current computational C-S-H models built from the empirical models and computer simulations. We review common applications of these computational models: the aluminum incorporation, the elastic and mechanical properties, the diffusion of water and ions in nanopores, and C-S-H/organic composites. Finally, we discuss some practical aspects of the computational models and their interpretation, as well as possible future directions.The authors would like to acknowledge funding from “Departamento de Educación, Política Lingüística y Cultura del Gobierno Vasco” (Grant No. IT912-16 and IT1639-22) and the technical and human support provided by the Scientific Computing Service of SGIker (UPV/EHU/ ERDF, EU). E.D.-R. also acknowledges the postdoctoral fellowship from “Programa Posdoctoral de Perfeccionamiento de Personal Investigador Doctor” of the Basque Government

Hysteresis from Multiscale Porosity: Modeling Water Sorption and Shrinkage in Cement Paste

Cement paste has a complex distribution of pores and molecular-scale spaces. This distribution controls the hysteresis of water sorption isotherms and associated bulk dimensional changes (shrinkage). We focus on two locations of evaporable water within the fine structure of pastes, each having unique properties, and we present applied physics models that capture the hysteresis by dividing drying and rewetting into two related regimes based on relative humidity (RH). We show that a continuum model, incorporating a pore-blocking mechanism for desorption and equilibrium thermodynamics for adsorption, explains well the sorption hysteresis for a paste that remains above approximately 20% RH. In addition, we show with molecular models and experiments that water in spaces of ≲1  nm width evaporates below approximately 20% RH but reenters throughout the entire RH range. This water is responsible for a drying shrinkage hysteresis similar to that of clays but opposite in direction to typical mesoporous glass. Combining the models of these two regimes allows the entire drying and rewetting hysteresis to be reproduced accurately and provides parameters to predict the corresponding dimensional changes. The resulting model can improve the engineering predictions of long-term drying shrinkage accounting also for the history dependence of strain induced by hysteresis. Alternative strategies for quantitative analyses of the microstructure of cement paste based on this mesoscale physical model of water content within porous spaces are discussed.Portland Cement AssociationNational Ready Mixed Concrete Association (Research and Education Foundation)Schlumberger Foundatio

Management of inflammatory bowel disease in France: a nationwide survey among private gastroenterologists

Introduction : Les données sur la gestion actuelle des patients atteints de maladie inflammatoire chronique intestinale (MICI) sont rares. Matériel et méthodes : Il s’agissait d’une enquête nationale sur internet réalisée auprès de gastro-entérologues libéraux sous forme de questions à choix multiples en Juin 2012. Résultats : 375 patients atteints de MICI ont été inclus : 48 % d’entre eux avaient une rectocolite hémorragique (RCH). Un antécédent d’hospitalisation concernait un tiers des patients atteints de MICI, et un antécédent de chirurgie 40 % des patients atteints de maladies de Crohn (MC). Deux tiers des patients avaient une maladie active le jour de la consultation (l’activité de la maladie était jugée par le médecin sans score). Soixante pour cent des patients atteints de RCH étaient traités par 5-aminosalicylés contre 18,5 % de MC (p<0,001). Parmi les patients traités par anti-TNF, seulement 4,5 % recevaient un traitement concomitant par immunomodulateur. La moitié des patients avaient eu une coloscopie dans l’année. Concernant le dépistage du cancer colorectal, des biopsies étagées et la chromoendoscopie étaient réalisées dans respectivement 75 % et 40 % des cas. Un score endoscopique d’activité n’était utilisé que chez 10 % des patients. Environ un tiers des patients ayant une MICI avait eu une imagerie dans l’année : l’entéro-IRM représentait environ la moitié de ces prescriptions. Le scanner a été prescrit chez 12 % des patients et l’échographie chez seulement 7 %. Conclusion : De nombreux patients ont encore une maladie active à l’ère des biothérapies, et la proportion de patients recevant une association anti-TNF et azathioprine reste faible en médecine libérale. La coloscopie est toujours la référence pour évaluer l’activité des MICI même si l’IRM est de plus en plus pratiquée. La chromoendoscopie et les scores endoscopiques sont encore sous-utilisés.Background: Data on the current management of inflammatory bowel disease (IBD) are scarce. Materials and Methods: This was a web-based nationwide survey consisting of multiple-choice questions among private gastroenterologists in France in June 2012. Results: 375 IBD patients were analyzed: 48% had ulcerative colitis (UC). History of hospitalization concerned one third of IBD patients, and history of surgery 40% of Crohn’s disease patients (CD). Two thirds of IBD patients had active disease (disease activity was judged by the physician without using a validated tool or a score). The proportion of patients treated with anti-TNF therapy was significantly lower in UC (18.9%) than in CD (38.9 %; p<0.0001). Sixty per cent of UC patients were treated with 5-aminosalicylates as compared with 18.5% of in CD (p<0.0001). Among anti-TNF treated patients, only 4.5% were receiving concomitant immunomodulator. Half of IBD patients had a colonoscopy within the past year. Regarding colorectal cancer screening, random biopsies and chromoendoscopy were performed in 75% and 40% of cases, respectively. An endoscopic score was used for only 10% of IBD patients. About one third of IBD patients had imaging studies within the past year, MRI enterography representing about half of them. Abdominal CT was prescribed for 12% of IBD patients and abdominal ultrasound for only 7% of them. Conclusions: Many patients still have active disease in the biologics era despite an increasing use of immunosuppressive therapy, and the number of patients receiving combination therapy is low in private practice. Colonoscopy remains the gold standard to assess IBD even though MRI is increasingly used in these patients. Chromoendoscopy and endoscopy scores are not often used

Cephalopod genomics: a plan of strategies and organization

The Cephalopod Sequencing Consortium (CephSeq Consortium) was established at a NESCent Catalysis Group Meeting, "Paths to Cephalopod Genomics-Strategies, Choices, Organization," held in Durham, North Carolina, USA on May 24-27, 2012. Twenty-eight participants representing nine countries (Austria, Australia, China, Denmark, France, Italy, Japan, Spain and the USA) met to address the pressing need for genome sequencing of cephalopod mollusks. This group, drawn from cephalopod biologists, neuroscientists, developmental and evolutionary biologists, materials scientists, bioinformaticians and researchers active in sequencing, assembling and annotating genomes, agreed on a set of cephalopod species of particular importance for initial sequencing and developed strategies and an organization (CephSeq Consortium) to promote this sequencing. The conclusions and recommendations of this meeting are described in this white paper

Cephalopod genomics : a plan of strategies and organization

© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Standards in Genomic Sciences 7 (2012): 175-188, doi:10.4056/sigs.3136559.The Cephalopod Sequencing Consortium (CephSeq Consortium) was established at a NESCent Catalysis Group Meeting, “Paths to Cephalopod Genomics- Strategies, Choices, Organization,” held in Durham, North Carolina, USA on May 24-27, 2012. Twenty-eight participants representing nine countries (Austria, Australia, China, Denmark, France, Italy, Japan, Spain and the USA) met to address the pressing need for genome sequencing of cephalopod molluscs. This group, drawn from cephalopod biologists, neuroscientists, developmental and evolutionary biologists, materials scientists, bioinformaticians and researchers active in sequencing, assembling and annotating genomes, agreed on a set of cephalopod species of particular importance for initial sequencing and developed strategies and an organization (CephSeq Consortium) to promote this sequencing. The conclusions and recommendations of this meeting are described in this White Paper.The Catalysis Group Meeting was supported by the National Science Foundation through the National Evolutionary Synthesis Center (NESCent) under grant number NSF #EF-0905606

Régime sans gluten

Tuberculosis, despite its prevention, remains an endemic affection in Morocco. Although rare, pseudo surgical forms and especially peritonitis are mainly due to delayed diagnosis. We report the case of a 30-year-old woman, admitted for peritonitis. The diagnosis of tuberculous peritonitis was established during surgery with macroscopic observation of granulations, and confirmed after biopsy specimens by identification of a giant lymph node cell granuloma with caseous necrosis. Outcome was favorable after appropriate antibiotic therapy. This observation emphasizes the fact that peritonitis, although a rare complication of peritoneal tuberculosis, poses problems of positive and differential diagnosis. Even if treatment is based on antituberculous quadritherapy, surgery is sometimes necessary and should be decided in due time

Risques et adaptation nutritionnelle en cancérologie

This article starts with a presentation of Caycedian Sophrology. We then evaluate its impact on stress reduction through a questionnaire on a students’ population. It appears that stress level increases between the two sessions in the control group while it decreases in the experimental group

Roflumilast in moderate-to-severe chronic obstructive pulmonary disease treated with longacting bronchodilators: two randomised clinical trials

Background Patients with chronic obstructive pulmonary disease (COPD) have few options for treatment. The efficacy and safety of the phosphodiesterase-4 inhibitor roflumilast have been investigated in studies of patients with moderate-to-severe COPD, but not in those concomitantly treated with longacting inhaled bronchodilators. The effect of roflumilast on lung function in patients with COPD that is moderate to severe who are already being treated with salmeterol or tiotropium was investigated. Methods In two double-blind, multicentre studies done in an outpatient setting, after a 4-week run-in, patients older than 40 years with moderate-to-severe COPD were randomly assigned to oral roflumilast 500 mu g or placebo once a day for 24 weeks, in addition to salmeterol (M2-127 study) or tiotropium (M2-128 study). The primary endpoint was change in prebronchodilator forced expiratory volume in 1s (FEV(1)). Analysis was by intention to treat. The studies are registered with ClinicalTrials.gov, number NCT00313209 for M2-127, and NCT00424268 for M2-128. Findings In the salmeterol plus roflumilast trial, 466 patients were assigned to and treated with roflumilast and 467 with placebo; in the tiotropium plus roflumilast trial, 371 patients were assigned to and treated with roflumilast and 372 with placebo. Compared with placebo, roflumilast consistently improved mean prebronchodilator FEV(1) by 49 mL (p<0.0001) in patients treated with salmeterol, and 80 mL (p<0.0001) in those treated with tiotropium. Similar improvement in postbronchodilator FEV(1) was noted in both groups. Furthermore, roflumilast had beneficial effects on other lung function measurements and on selected patient-reported outcomes in both groups. Nausea, diarrhoea, weight loss, and, to a lesser extent, headache were more frequent in patients in the roflumilast groups. These adverse events were associated with increased patient withdrawal. Interpretation Roflumilast improves lung function in patients with COPD treated with salmeterol or tiotropium, and could become an important treatment for these patients