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Dystrophia myotonica type 1 (DM1) results from nuclear sequestration of splicing factors by a messenger RNA (mRNA) harboring a large (CUG)n repeat array transcribed from the causal (CTG)n DNA amplification. Several compounds were previously shown to bind the (CUG)n RNA and release the splicing factors. We now investigated for the first time the interaction of an aliphatic polycarbonate carrying guanidinium functions to DM1 DNA/RNA model probes by affinity capillary electrophoresis. The apparent association constants (Ka) were in the range described for reference compounds such as pentamidine. Further macromolecular engineering could improve association specificity. The polymer presented no toxicity in cell culture at concentrations of 1.6–100.0 μg/mL as evaluated both by MTT and real-time monitoring xCELLigence method. These promising results may lay the foundation for a new branch of potential therapeutic agents for DM1.

Purpose This aim of this work is to investigate different modelling approaches for air-cooled data centres. The study employs three computational methods, which are based on finite element, finite volume and lattice Boltzmann methods and which are respectively implemented via commercial Multiphysics software, open-source computational fluid dynamics code and graphical processing unit-based code developed by the authors. The results focus on comparison of the three methods, all of which include models for turbulence, when applied to two rows of datacom racks with cool air supplied via an underfloor plenum. Design/methodology/approach This paper studies thermal airflows in a data centre by applying different numerical simulation techniques that are able to analyse the thermal airflow distribution for a simplified layout of datacom racks in the presence of a computer room air conditioner. Findings Good quantitative agreement between the three methods is seen in terms of the inlet temperatures to the datacom equipment. The computational methods are contrasted in terms of application to thermal management of data centres. Originality/value The work demonstrates how the different simulation techniques applied to thermal management of airflow in a data centre can provide valuable design and operational understanding. Basing the analysis on three very different computational approaches is new and would offer an informed understanding of their potential for a class of problems.

Different P3HT chain lengths have been synthesized, functionalized at both chain ends with aldehyde moieties and finally cyclized following the McMurry reaction in a pseudo high dilution process. The confirmation of the high yielded intramolecular coupling came from the decrease of the hydrodynamic radius observed by SEC, correlated to the conservation of the mass distribution by MALDI-ToF and by the very low content of residual linear precursor estimated by NMR. Different aggregation behaviors between linear and cyclic and between short and long systems have been pointed out by DSC and UV–vis absorption spectroscopy. We estimate that long cyclic structures present similar aggregation behavior than long linear ones mainly due to the folding of those chains.

We have studied how cyclic topology affects the crystallization and morphology of π-conjugated poly(3- hexylthiophene) (P3HT) molecules by comparing linear and cyclic analogues for the first time, with three different chain lengths. We employ a range of experimental techniques including wide-angle X-ray scattering (WAXS), polarized light optical microscopy (PLOM), differential scanning calorimetry (DSC) and a combination of Polarized Light Optical Microscopy (PLOM) and Spectroscopy (S). The crystallization and melting points, melting/crystallization enthalpies, and overall crystallization kinetics of cyclic P3HTs are found to be substantially lower than their linear counterparts. The results are explained by the higher rigidity of cyclic molecules, as predicted by density functional theory (DFT) calculations, in the low molecular weight range explored here, in comparison with linear P3HT chains. Additionally, we have found that cyclic P3HT can form liquid crystalline phases above their crystalline melting points and a new crystal form at lower temperatures. PLOM, WAXS, DSC and PLOM/S results indicate that cyclic P3HTs display bipolar and concentric nematic textures that disappear at a well-defined nematic-isotropic transition temperature. Such liquid crystalline textures are completely absent in the linear P3HTs analogues studied here. We conclude that the cyclic topology induces the formation of liquid crystalline phases as the rigid P3HT oligomers can self-assemble above their crystalline melting temperatures. J.M. acknowledges support from the Provincial Council of Gipuzkoa under the program Fellow Gipuzkoa and “Fomento San Sebastián” in the framework program “Retorno del Talento Local” Donostia up! 2016. We acknowledge the help of Dr. Jaime Martín and Ms. Sara Marina with the combined Microscopy/Spectroscopy measurements. J.M. and A.J.M. acknowledge funding by Mineco MAT2017- 83014-C2-1-P project. N.D. and O.C. are grateful to the Science Policy Office of the Belgian Federal Government (PAI 7/5) and to the Belgian FRFC-FNRS (n°2.4508.12). O.C. is Research Associates of the F.R.S.-FNRS. G.L. is grateful to the Youth Innovation Promotion Association of the Chinese Academy of Sciences (2015026). D.W. and A.J.M acknowledge the support from the National Natural Science Foundation of China (51820105005). All authors gratefully acknowledge the support of the EU through the H2020-MSCA-RISE-2017-778092 BIODEST project. Technical and human support provided by IZO-SGI, SGIker (UPV/EHU, MICINN, GV/EJ, ERDF and ESF) is gratefully acknowledged for assistance and generous allocation of computational resources.

For the first time, the effectiveness of triazolinedione (TAD) click chemistry onto aliphatic polycarbonates (APC) is demonstrated. Statistic copolymers carrying click-reactive conjugated diene (in a ratio of 10%) are synthesized via organocatalyzed ring-opening polymerization. The highly efficient click reaction of TADs carrying simple butyl and phenyl functions are confirmed by 1 H-NMR and DSC. Network formation using a bivalent TAD is also performed and simply characterized by DSC. This post-polymerization functionalization of biocompatible and biodegradable APC pave the way to easy and versatile "on-demand" materials design.

This work deals with the synthesis and characterization of new diblock copolymers based on π-conjugated and depolymerizable units. These diblock copolymers are based on a regioregular poly(3-hexylthiophene) sequence associated with a sacrificial block, namely polyphthalaldehyde. The conjugated polymer was obtained by Grignard metathesis polymerization and end-capped by an alkynyl group while the depolymerizable segment was synthesized by an anionic cyclopolymerization from an azide moiety. Diblock copolymers with different molecular weights were then successfully synthesized via an alkyne–azide coupling reaction. Under specific conditions, these copolymers self-assemble into fibrillar nanostructures in thin films. The elimination of polyphthalaldehyde was carried out by thermal treatment, generating nanoporous poly(3-hexylthiophene) films. The use of a dry treatment to remove the polyphthalaldehyde block strongly reduces the morphological damages that would occur with a “wet” processing route. These nanop...

International audience; We introduce recodable surfaces solely based on reversible artificial hydrogen bonding interactions. We show that a symmetrical oligoamide (SOA) attached to poly(methyl methacrylate) (PMMA) can be repeatedly immobilized and cleaved off spatially defined surface domains photochemically functionalized with asymmetric oligoamides (AOAs). The spatially resolved recodability is imaged and quantified via ToF-SIMS.

Simulation tools for thermal management of data centers help to improve layout of new builds or analyse thermal problems in existing data centers. The development of LBM on remote GPUs as an approach for such simulations is discussed making use of VirtualGL and prioritised multi-threaded implementations of an existing LBM code. The simulation is configured to model an existing and highly monitored test data center. Steady-state root mean square averages of measured and simulated temperatures are compared showing good agreement. The full capability of this simulation approach is demonstrated when comparing rack temperatures against a time varying workload, which employs time-dependent boundary conditions.

A novel lattice Boltzmann method (LBM) based 3D computational fluid dynamics (CFD) technique has been implemented on the graphics processing unit (GPU) for the purpose of simulating the indoor environment in real-time. We study the time evolution of the turbulent airflow and temperature inside a test chamber and in a simple model of a four-bed hospital room. The predicted results from LBM are compared with traditional CFD based large eddy simulations (LES). Reasonable agreement between LBM results and LES method is observed with significantly faster computational times.

The association of kinetic studies, DFT calculations and 1H–7Li NMR analyses allowed the control of the cyclo-ATRP of PEG9DMA and the production of polymethacrylate pseudo crown-ethers of various molar masses. Their potential to act as a solid-state polymer electrolyte in Li-ion batteries has been highlighted and may come from the supramolecular organization of the cyclo-PEG forming a Li+ diffusion channel.

Real-time fluid simulation is an active field of research in computer graphics, but they usually focus on visual impact rather than physical accuracy. However, by combining a lattice Boltzmann model with the parallel computing power of a graphics processing unit, both real-time compute capability and satisfactory physical accuracy are now achievable. The implementation of an optimized 3D real-time thermal and turbulent fluid flow solver with a performance of half a billion lattice node updates per second is described in detail. The effects of the hardware error checking code and the competition between appropriate boundary conditions and performance capabilities are discussed.

A series of four conjugated molecules consisting of a fluorenone central unit symmetrically coupled to different oligothiophene segments are conceptually designed and synthesized to provide new electroactive materials for application in photovoltaic devices. The combination of electron-donating oligothiophene building blocks with an electron-accepting fluorenone unit results in the emergence of a new band assigned to an intramolecular charge transfer transition that gives rise to the extension of the absorption spectral range of the resulting molecules. Detailed spectroscopic and voltammetric investigations show that all studied molecules have highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) level positions, which make them good candidates for the application as electron-donors in bulk-heterojunction photovoltaic cells, with (6,6)-phenyl-C61-butyric acid methyl ester (PCBM)-C60 as electron acceptor component. Moderate device performances, with power conversion efficiencies (PCEs) comprised between 0.3 and 0.6%, were obtained with rigid molecules, containing either the bridging units between the thiophene rings, i.e., (2,7-bis(4,4 0 -dioctyl-cyclopenta[2,1-b:3,4-b 0 ]dithiophen-2yl)-fluoren-9-one (SCPTF) and 2,7-bis(4-(dioctylmethylene)-cyclopenta[2,1-b:3,4-b 0 ]dithiophen-5-yl)-fluoren-9-one (MCPTF) or a vinylene unit 2,7-bis(5-[(E)-1,2-bis(3-octylthien-2-yl)ethylene])-fluoren-9-one (TVF), whereas with (2,7-bis-(3,3 000 -dioctyl[2,2 0 ;5 0 ,2 00 ;5 00 ,2 000 ]quaterthiophen-5-yl)-fluoren-9-one (QTF) PCE up to 1.2% (under AM 1.5 illumination, 100mW cm � 2 , active area 0.28cm 2 ) was obtained. The strong p-stacking interactions in the solid state for this oligomer leading to improved morphology could explain the good performances of QTF-based devices, which rank among the highest recorded for nonpolymeric materials. Consequently, fluorenone-based non-polymeric molecules constitute highly attractive materials for solution-processable solar cell applications.

International audience; We designed efficient precursors that combine complementary associative groups with exceptional binding affinities and thiocarbonylthio moieties enabling precise RAFT polymerization. Well defined PS and PMMA supramolecular polymers with molecular weights up to 30 kgmol(-1) are synthesized and shown to form highly stable supramolecular diblock copolymers (BCPs) when mixed, in non-polar solvents or in the bulk. Hierarchical self-assembly of such supramolecular BCPs by thermal annealing affords morphologies with excellent lateral order, comparable to features expected from covalent diblock copolymer analogues. Simple washing of the resulting materials with protic solvents disrupts the supramolecular association and selectively dissolves one polymer, affording a straightforward process for preparing well-ordered nanoporous materials without resorting to crosslinking or invasive chemical degradations.

Spray cooling is one of the most promising methods of cooling high heat flux electronics. Depending on the type of the nozzle, spray cooling can be categorized as single-phase or two-phase. In the latter, which is known to be more effective, a secondary gas is used to further pressurize the liquid and form smaller droplets at higher velocities. The gas is also assumed to assist the spreading phase by imposing normal and tangential forces on the droplet free surface which adds to the complicated hydrodynamics of the droplet impact. Moreover, the order of magnitude of droplet size in spray cooling is 10−6 m, thereby introducing a low Weber and Reynolds numbers’ impact regime which heretofore has not been well understood. A 3D lattice Boltzmann method was implemented to simulate the impact of a single micro-droplet on a dry surface both in ambient air and under a stagnation gas flow. Two cases were closely compared and correlations were proposed for the instantaneous spreading diameter. Contrary to recent findings at higher impact Weber and Reynolds numbers, it was found that a stagnation flow only significantly affects the spreading phase for Ca* ≥ 0.35 but has little influence on the receding physics.

A series of p-type alternating copolymers based on oligothiophene and fluorene electron-donating units, and fluorenone or benzothiadiazole electron-withdrawing units was synthesised via Suzuki coupling reaction. Their optical, electrochemical and photovoltaic properties were investigated in detail allowing rational rules to be drawn on the structure–property relationships. We highlight in this work the crucial role of the side solubilizing groups attached to the polymer backbones that have a significant impact on the morphology of the blends and the solar cell's power conversion efficiency. Devices with an active area of 0.28 cm2, based on fluorenone-copolymers and [70]PCBM blends showed Voc up to 0.95 V and Power Conversion Efficiencies (PCE) up to 1.82% under AM1.5 simulated sunlight (100 mW cm−2) conditions. These values are improved compared to the ones reported to date for this class of materials.

International audience; A new approach toward the tuning of the supramolecular organization of π-conjugated substructures containing imide functional groups has been investigated using the concept of supramolecular chemistry. This approach, which allows enhanced emission properties of the active material, was evaluated in the fabrication of optoelectronic devices. A linear ditopic chromophore H-ImPV was synthesized. This N−H imide constitutes a recognizing unit with an acceptor−donor−acceptor (ADA) hydrogen bond motif. End-capping of this new chromophore with a monotopic structuring unit allowed control of the supramolecular aggregation of the π-conjugated chromophore. The studies of the absorption and emission properties of the H-ImPV, in solution or in the solid state (thin films, powders), clearly revealed different aggregation behaviors, depending on the presence of the monotopic structuring unit: hindered unit (Cy-DAT) led to the formation of J-aggregates. In all cases, evidence for the heteromolecular association H-ImPV···Cy-DAT was obtained from an infrared absorption band located at 2715 cm−1, which was typical of the hydrogen bonding present in the ADA···DAD triplet. This has been illustrated by the fabrication of light-emitting devices based on films of H-ImPV and [H-ImPV.(Cy-DAT)2]. H-ImPV presents a poor ability to emit light, because of its aggregation, which induces quenching of luminescence. The high efficiencies exhibited by the devices based on a single layer of [H-ImPV.(Cy-DAT)2] are the result of the J-aggregation of chromophores, because of the bulky cyclohexyl fragments of the Cy-DAT. Tuning of the supramolecular organization of the H-ImPV by the addition of two equivalents of Cy-DAT in the active layer allowed recovery of the performances exhibited by the organic light-emitting devices (OLEDs) of the isolated chromophore. Therefore, the use of Cy-DAT is an interesting alternative to avoid aggregation and to significantly increase luminance. As a consequence, the luminous efficiencies of the devices are much better for the coassembled active layer.

New π-conjugated alternating copolymers containing thienylene and fluorenone units, namely poly[(5,5‴-dioctyl-[2,2′;5′,2″;5″,2‴]quaterthiophene)-alt-(2,7-fluoren-9-one)] (PQTF8), as well as its analogue without fluorenone groups (PQT8), have been synthesized. Absorption studies carried out both in solution and in thin films indicate that the presence of fluorenone chromophores in PQTF8 leads to a significant extension of the absorption spectrum in the visible range as compared to PQT8. The redox properties of both polymers, in particular their LUMO and HOMO levels, have been characterized by cyclic voltammetry and have been found suitable for potential use of these systems in organic solar cells. Finally, these materials have been tested as donor components in bulk-heterojunction-type photovoltaic cells using PCBM as an electron acceptor. We demonstrate a strong effect of the polymer's molecular weight on crucial cell parameters, such as the short-circuit current density Jsc, and therefore on the overall cell efficiency. This effect is particularly pronounced for PQTF8-based cells leading to power conversion efficiencies up to 1.5% for the highest molecular weights.