Adhesively Bonded FRP Reinforcement of Steel Structures: Surface Preparation Analysis and Influence of the Primer

International audienceAbstract In tropical areas, with marine environment, high temperature and humidity, corrosion is a constant threat. The maintenance of steel structures (like FPSO’s) is becoming a challenge. The current technique of “crop and renewing” repair involves a certain number of major issues for project owners such as: “hot work”, that is to say welding; temporary weakening of the structure; need to empty, clean and purging the oil tanks of the FPSO’s, resulting in long downtime and an expensive solution. “Cold repair”, such as composite repair, is a promising solution. However, surface preparation and the influence of the primer are crucial issues to be addressed to ensure the strength and reliability of this type solution based on bonded patch. The paper presents an experimental study of the influence of the surface preparation and the primer on the strength of small steel bonded specimens which have been deliberately degraded by corrosion and pollution. Several surface preparation methodologies were investigated and the quality of these preparations was assessed using methods that can be implemented on site. Two main aspects were investigated: the detection of the residual presence of pollutants through the use of a portable infrared spectrometer; and the determination of surface energy after preparation using contact angle and wettability measurement equipment. To study the impact of the primer on the adhesion capacity of the steel surface, critical toughnesses measurements was performed with End notch flexure tests. Three configurations have been tested: bonding with the epoxy resin without initial application of primer and bonding with the Epoxy resin with initial application of two Primer A and B. The results shown clearly that the type of primer and the quality of its application are paramount importance to ensure the strength of steel bonded patches

Successful treatment of Trichosporon asahii fungemia with isavuconazole in a patient with hematologic malignancies

International audienceTrichosporon spp. are yeast-like microorganisms responsible for skin, urinary, pulmonary, or bloodstream infections. Due to intrinsic resistance to echinocandins, poor susceptibility to polyenes, and preferred occurrence in immunocompromised patients, such infections are often of poor prognosis. Yet no consensual therapeutic guidelines are presently available. Several clinical cases of Trichosporon infections have been successfully treated with azole therapy, including voriconazole which appeared frequently effective against Trichosporon both in vitro and in vivo. However, the low efficacy associated with some Trichosporon genotypes, complex pharmacokinetics, and the side effects of voriconazole represent limitations for its use and has prompted a search for other therapeutic options. Here, we report a case of T. asahii fungemia in a patient with B-cell acute lymphoblastic leukemia which was successfully treated with isavuconazole consecutive to stopping voriconazole therapy due to severe side effects. This observation suggests that isavuconazole with a similar spectrum to voriconazole, fewer pharmacology interactions, and side effects may be considered as a valuable therapeutic option against Trichosporon infections

Use of high spatial resolution distributed optical fiber to monitor the crack propagation of an adhesively bonded joint during ENF and DCB tests

International audienceSimilarly to other industrial areas, there is a strong interest for the use of bonded FRP (Fiber Reinforced Polymers) repair or reinforcement for steel structures in the case of offshore applications. However, the reliability of the adhesively bonded (FRP) shall stand as high as steel renewal, this requires additional developments, in particular, a complete understanding of the repair mechanical strength which depends on material and interfacial properties. Fracture mechanics is an interesting approach to assess the risk to undergo interlaminar fracture or steel to adhesive interfacial disbonding failure. The experimental determination of the required design values for this an approach (critical toughness) are generally obtained using common tests such as Double Cantilever Beam (DCB), End Notched Flexure (ENF) or Mixed Mode Bending (MMB) tests. These tests require a precise crack length monitoring that is currently carried out using visual observation or Digital Image Correlation (DIC) on the flank of the sample. This may induce error in crack length measurement especially if the crack doesn't remain straight during the test. The paper presents a study of crack front monitoring by a distributed optical fiber as an alternative to the standard techniques to monitor crack front and to determine the critical toughness in mode I and II through respectively, DCB (Double Cantilever Beam) and ENF (End Notched Flexure) tests. Firstly, the issues related to the use of this continuous optical fiber are raised (insertion, precision resolution, measurement noise, exploitation methodologies). Then, some experimental investigations on ENF and DCB tests are presented and analyzed using the proposed methodology to monitor crack propagation using the optical fiber strain measurement. The obtained results are compared, focusing on the proper determination of the critical toughness of the adhesive. These results show that an optical fiber bonded on the surface of the sample can be used to measure and follow the crack propagation during the test which simplifies and adds precision to the standardize critical toughness computation method

High frequency of central nervous system involvement in transformed Waldenstrom macroglobulinemia

Histologicaltransformation (HT) to diffuse large B-cell lymphoma (DLBCL) is a rare event in Waldenström macroglobulinemia (WM) and is associated with a poor prognosis.1-4 It confers an inferior outcome compared with WM patients without HT.2,3 Most transformed WM patients present with elevated serum lactate dehydrogenase (LDH) levels and extranodal disease.1 Among extranodal sites, the central nervous system (CNS) is one of the most frequently involved sites identified at diagnosis of transformed WM (ranging from 13% to 18%).1,3 However, the prognostic value of CNS involvement is unknown, and the rate of CNS involvement at relapse has not been previously reported in this setting.This work was supported by Cancer Research UK [C355/A26819], FC AECC, and AIRC under the “Accelerator Award Program” [EDITOR] to M.A. and R.G.-S

Functionalization of porous hydroxyapatite for prolonged release of antibiotics

L'os est un organe complexe, siège d'un équilibre fragile entre les cellules le constituant. Les nombreuses pathologies pouvant l'affecter, bien identifiées et documentées, restent difficiles à traiter. L'ablation des parties osseuses lésées par des cancers ou des ostéomyélites, parfois seul recours, conduit à l'emploi de matériaux de substitution. Les conséquences d'un tel acte chirurgical peuvent être l'infection, ou la récidive du développement de la lésion. Le but de notre travail a été de traiter un substrat d'hydroxyapatite poreuse (HA), matière d'une constitution proche de cel1e de l'os, dans le but de lui conférer des propriétés de délivrance d'antibiotiques améliorées et d'obtenir ainsi un substitut osseux « actif» contre les infections péri- et postopératoires. Le phénomène de libération contrôlée a été obtenu par l'incorporation et la fixation de la cyclodextrine dans la structure poreuse de l'HA, par réticulation avec un acide polycarboxylique. Une fois le procédé et les paramètres de fonctionnalisation établis, une étude in vitro a été menée afin de vérifier la biocompatibilité de ce système. Enfin, nous avons pu mesurer une hausse de la capacité d'adsorption de l'HA traitée vis-à-vis de la ciprofloxacine et de la vancomycine, suivie d'une cinétique de libération in vitro prolongée dans le temps.Bone presents a complex structure, a delicate balance between the constituent cells. The many well-identified and documented diseases that can affect it remain difficult to treat. The removal of the bony parts affected by cancer or osteomyelitis, generally leads to the use of substitute materials. The consequences of such a surgical act can be infection, or the recurrence of the lesion development. The goal of our work was to treat a porous substrate of hydroxyapatite (HA), which has a similar constitution as bone, in order to improve the propenies of controlled release of antibiotics and to obtain an "activated" bone substitute that is efficient against postoperative infections. The phenomenon of controlled release was obtained by the incorporation and fixation of cyclodextrin in the porous structure of the HA and by cross-linking it with a polycarboxylic acid. Once the process and functionalization parameters established, in vitro studies were conducted to verify the biocompatibility of the system. Finally, we could measure an increase of ciprofloxacin and vancomycin adsorption capacity of the treated HA, followed by a in vitro release kinetics prolonged in time

Systematic review of the recent evidence for the efficacy and safety of chlorambucil in the treatment of B-cell malignancies

International audienceEmergence of new agents has deeply modified treatment options and the role of chlorambucil (CLB) in B-cell malignancies. We conducted a systematic review of prospective, randomized, controlled trials (RCTs) investigating the benefits and harms of CLB used alone or in combination with other treatment in patients suffering from chronic lymphocytic leukemia (CLL), low-grade non-Hodgkin lymphoma (NHL) or Waldenström macroglobulinemia (WM). For CLL, review of the nine RCTs showed that the main advantage of CLB is its low toxicity in comparison with purine nucleoside analogs like fludarabine in either CLL or NHL. In CLL, the major disadvantage is the very low rate of complete response, except when combining an anti-CD20 antibody. For B-cell lymphoma and WM, six RCTs were summarized. Results according to the usual criteria are presented and the role of CLB, used mostly in combination with an anti-CD20 antibody, is discussed for each indication, in particular for unfit patients

Voltage-Gated Potassium Channel Antibody Paraneoplastic Limbic Encephalitis Associated with Acute Myeloid Leukemia

Among paraneoplastic syndromes (PNS) associated with malignant hemopathies, there are few reports of PNS of the central nervous system and most of them are associated with lymphomas. Limbic encephalitis is a rare neurological syndrome classically diagnosed in the context of PNS. We report the case of a 81-year-old man who presented with a relapsed acute myeloid leukemia (AML) with minimal maturation. He was admitted for confusion with unfavorable evolution as he presented a rapidly progressive dementia resulting in death. A brain magnetic resonance imaging, performed 2 months after the onset, was considered normal. An electroencephalogram showed non-specific bilateral slow waves. We received the results of the blood screening of neuronal autoantibodies after the patient's death and detected the presence of anti-voltage-gated potassium channel (VGKC) antibodies at 102 pmol/l (normal at <30 pmol/l). Other etiologic studies, including the screening for another cause of rapidly progressive dementia, were negative. To our knowledge, this is the first case of anti-VGKC paraneoplastic limbic encephalitis related to AML

Cross-Linked Artificial Enzyme Crystals as Heterogeneous Catalysts for Oxidation Reactions

International audienceDesigning systems that merge the advantages of heterogeneous catalysis, enzymology, and molecular catalysis represents the next major goal for sustainable chemistry. Cross-linked enzyme crystals display most of these essential assets (well-designed mesoporous support, protein selectivity, and molecular recognition of substrates). Nevertheless, a lack of reaction diversity, particularly in the field of oxidation, remains a constraint for their increased use in the field. Here, thanks to the design of cross-linked artificial nonheme iron oxygenase crystals, we filled this gap by developing biobased heterogeneous catalysts capable of oxidizing carbon-carbon double bonds. First, reductive O2 activation induces selective oxidative cleavage, revealing the indestructible character of the solid catalyst (at least 30 000 turnover numbers without any loss of activity). Second, the use of 2-electron oxidants allows selective and high-efficiency hydroxychlorination with thousands of turnover numbers. This new technology by far outperforms catalysis using the inorganic complexes alone, or even the artificial enzymes in solution. The combination of easy catalyst synthesis, the improvement of "omic" technologies, and automation of protein crystallization makes this strategy a real opportunity for the future of (bio)catalysis

Predictive value of 18F-FDG PET/CT in adults with T-cell lymphoblastic lymphoma: post hoc analysis of results from the GRAALL-LYSA LLO3 trial

International audienceWe examined whether FDG PET can be used to predict outcome in patients with lymphoblastic lymphoma (LL)