Synthesis and characterization of side-chain oxazoline–methyl methacrylate copolymers bearing azo-dye

We synthesized new polymeric structures by attaching a side-chain azo-moiety on poly(oxazoline) and poly(oxazoline-co-methyl methacrylate)s. For the polymer analogous transformation, we took advantage of the highly effective ring-opening addition of carboxyl group to the oxazoline cycle. The comonomers feed ratio allowed us to control the composition of the products while the kinetic treatment, employing an integral method, revealed a statistical copolymerization tendency of 2-isopropenyl-2-oxazoline with methyl methacrylate in acetonitrile at 70 °C. The elemental analysis and ¹H NMR spectroscopy provided almost identical composition data for both the substrates and the side-chain copolymers. The UV spectroscopy sustained the quantitative addition of 4-(4-hydroxy-3,5-dimethylphenylazo)benzoic acid to the oxazoline rings. Both the unmodified copolymers and the coloured ones exhibited good thermal stabilities, up to 371 °C and 302 °C, respectively. The glass transition temperatures ranged from 141.5 to 177.5 °C and from 153.8 to 200.9 °C for the substrates and for the modified copolymers, respectively. Preliminary investigations showed fluorescence activity for all copolymers bearing azo-moieties.     

Integrated analysis of non-linear loss mechanisms in Yb:YAG ceramics for laser applications

Transparent 9.8 at% Yb:YAG ceramic samples were prepared by reactive sintering of commercial oxides and using 0 or 1 wt% polyethylene glycol (PEG) as dispersant. The optical quality of the samples turns out to be improved by using a dispersant and optical transmittance close to the commercial samples has been obtained. On the other hand the laser characterization evidenced the activation of a non-linear loss mechanism occurring only in the sample containing PEG and despite its better optical quality, at high excitation level. A SEM analysis of material microstructure could not explain this behavior. A state of the art TEM analysis at nanometric scale was performed providing high resolution chemical spectroscopic results that indicate the presence of amorphous and crystalline silicate phases playing different roles in the two samples.     

Chitosan‐sodium lauryl ether sulfate particles and their use for adsorption of Cu(II) ions

The synthesis of small particles through the interaction between chitosan (CS) and sodium lauryl ether sulfate (SLES) was studied. Depending on working condition, microparticles at atmospheric pressure and ultrafine particles at high pressure have been obtained. At atmospheric pressure, the microparticles were formed instantaneously when the CS solution was dripped into the SLES aqueous solution. To obtain ultrafine particles, the surfactant solution in contact with high pressure carbon dioxide was sprayed into chitosan solution. Fourier Transform Infrared Spectroscopy proves the interaction between the sulfate groups of SLES and the amino groups of CS. The Scanning Electron Microscopy reveals that the microparticles are quasi‐spherical, but some of them can take the form of pellets depending on preparation conditions. The obtained microparticles were successfully used to uptake Cu(II) ions from aqueous solutions. The adsorption of Cu(II) depends on pH being maximum at pH = 5.5. The kinetic experiments demonstrated that Cu(II) adsorption onto CS/SLES microparticles obeys the Langmuir model. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40059.     

Pushing the Limits of Medical Management in HCM: A Review of Current Pharmacological Therapy Options

Hypertrophic cardiomyopathy (HCM) is the most common monogenic cardiac disease with a highly variable phenotypic expression, ranging from asymptomatic to drug refractory heart failure (HF) presentation. Pharmacological therapy is the first line of treatment, but options are currently limited to nonspecific medication like betablockers or calcium channel inhibitors, with frequent suboptimal results. While being the gold standard practice for the management of drug refractory HCM patients, septal reduction therapy (SRT) remains an invasive procedure with associated surgical risks and it requires the expertise of the operating centre, thus limiting its accessibility. It is therefore with high interest that researchers look for pharmacological alternatives that could provide higher rates of success. With new data gathering these past years as well as the development of a new drug class showing promising results, this review provides an up-to-date focused synthesis of existing medical treatment options and future directions for HCM pharmacological treatment.     

Integrating Multiple Resistive Memory Devices on a Single Carbon Nanotube

Nano‐objects would be of great interest for the development of new types of electronic circuits if one could combine their nanometer scale with original functionalities beyond the conventional transistor action. However, the associated circuit architectures will have to handle the increasing variability and defect rate intrinsic to the nanoscale. In this context, there is a very fast growing interest for memory devices, and in particular resistive memory devices, used as building blocks in reconfigurable circuits tolerant to defects and variability. It was recently shown that optically gated carbon nanotube field effect transistors (OG‐CNTFETs) based on large assemblies of nanotubes covered by an organic photoconductive thin film can be operated as programmable resistors and thus used as artificial synapses in circuits with function‐learning capabilities. Here, the potential of such approach is evaluated in terms of scalability by integrating and addressing several individually programmable resistances on a single carbon nanotube. In addition, the charge storage mechanism can be controlled at a length scale smaller than the device length allowing to also program the direction in which the current flows. It thus demonstrates that a single nanotube section can combine all‐in‐one the properties of an analog resistive memory and of a rectifying diode with tunable polarity.     

Coumarin-Tagged Dinuclear Trithiolato-Bridged Ruthenium(II)⋅Arene Complexes: Photophysical Properties and Antiparasitic Activity

The synthesis, characterization, photophysical and biological properties of 13 new conjugate coumarin-diruthenium(II)⋅arene complexes against Toxoplasma gondii are presented. For all conjugate organometallic unit/coumarins, an almost complete loss of fluorescence efficacy was observed. However, the nature of the fluorophore, the type of bonding, the presence and length of a linker between the coumarin dye and the ruthenium(II) moiety, and the number of dye units influenced their biological properties. The in vitro activity against a transgenic T. gondii strain grown in human foreskin fibroblasts (HFF) leads to IC₅₀ values for T. gondii β-gal from 105 to 735 nM. Of note is that nine compounds displayed lower IC₅₀ than the standard drug pyrimethamine. One compound applied at its IC₅₀ did not affect B-cell proliferation but had an impact on T-cell proliferation in murine splenocyte cultures. Transmission electron microscopy of T. gondii β-gal-infected HFF showed that treatment predominantly affected the parasites’ mitochondrion.     

DC performance, AC loss and transient field stability of five medium size NbTi cable-in-conduit conductors with parametric variations

Five medium size NbTi cable-in-conduit conductors with parametric variations in the cable layout were fabricated of three different strands to investigate their DC performance, AC loss behaviour and transient stability by means of the SULTAN facility. A comparison of measured strand data and the cable performances at the same background field indicates that the current carrying capacity of the conductors is limited by the total magnetic field on the high field side. Due to the self-field contribution the total magnetic field on the high field side is considerably larger than the background field at high currents. The take-off electric fields were found to decrease with increasing quench currents, resulting in sudden take-offs for large overall current densities. Effective self-field factors are used to describe the DC performance in the current range, where the critical current and the current sharing temperature are accessible. The quench behaviour of the conductors is discussed in the framework of a model based on peak-field-induced quenches. Differences in the DC performance of the conductors are related to the variation in the transverse resistance determining the ability of the conductors to redistribute the current in the case of a current imbalance originated at the joints. This aspect was studied in more detail by modifying one of the joints allowing a defined number of subcables to be disconnected. The voltage-current characteristics of strands and cable-in-conduit conductors are compared. The reasons for cable n values deviating from the strand n values are discussed. Moreover, the effect of different transverse resistances on the AC loss behaviour and the transient field stability was investigated. Ni coating of the strands was found to be sufficient to eliminate the interstrand coupling current loss. Thus, additional subcable wraps provided no significant further loss reduction.     

Cellular and Molecular Targets of Nucleotide-Tagged Trithiolato-Bridged Arene Ruthenium Complexes in the Protozoan Parasites Toxoplasma gondii and Trypanosoma brucei

Toxoplasma gondii is an apicomplexan parasite that infects and proliferates within many different types of host cells and infects virtually all warm-blooded animals and humans. Trypanosoma brucei is an extracellular kinetoplastid that causes human African trypanosomiasis and Nagana disease in cattle, primarily in rural sub-Saharan Africa. Current treatments against both parasites have limitations, e.g., suboptimal efficacy and adverse side effects. Here, we investigate the potential cellular and molecular targets of a trithiolato-bridged arene ruthenium complex conjugated to 9-(2-hydroxyethyl)-adenine (1), which inhibits both parasites with IC₅₀s below 10⁻⁷ M. Proteins that bind to 1 were identified using differential affinity chromatography (DAC) followed by shotgun-mass spectrometry. A trithiolato-bridged ruthenium complex decorated with hypoxanthine (2) and 2-hydroxyethyl-adenine (3) were included as controls. Transmission electron microscopy (TEM) revealed distinct ultrastructural modifications in the mitochondrion induced by (1) but not by (2) and (3) in both species. DAC revealed 128 proteins in T. gondii and 46 proteins in T. brucei specifically binding to 1 but not 2 or 3. In T. gondii, the most abundant was a protein with unknown function annotated as YOU2. This protein is a homolog to the human mitochondrial inner membrane translocase subunit Tim10. In T. brucei, the most abundant proteins binding specifically to 1 were mitochondrial ATP-synthase subunits. Exposure of T. brucei bloodstream forms to 1 resulted in rapid breakdown of the ATP-synthase complex. Moreover, both datasets contained proteins involved in key steps of metabolism and nucleic acid binding proteins.