(E)-N-{(E)-2-[(3,5-Dimethylbiphenyl-4-yl)imino]­acenaphthen-1-yl­idene}-2,6-di­methyl-4-phenyl­aniline

The title compound, C40H32N2, has crystallographic twofold rotation symmetry, with two C atoms lying on the axis. The dihedral angle between the two benzene rings of the 4-phenyl-2,6-dimethyl­phenyl group is 35.74 (17)°. The acenaphthene ring makes an angle of 76.93 (11)° with the benzene ring bonded to the N atom and an angle of 41.53 (13)° with the other benzene ring

(Z)-3-Chloro-N-[(Z)-3-(3-chloro-2-methyl­phenyl­imino)­butan-2-yl­idene]-2-methyl­aniline

In the title compound, C18H18Cl2N2, the complete molecule is generated by the application of C 2 symmetry. The C=N bond has an E configuration. The dihedral angle between the benzene ring and the 1,4-diaza­butadiene plane is 66.81 (9)°

Controlled reversible debundling of single-walled carbon nanotubes by photo- switchable dendritic surfactants

Stimulus responsive surfactants based on dendritic glycerol azobenzene conjugates were used to solubilize and debundle single-walled carbon nanotubes in aqueous media. Their debundling property as well as their reaggregation behavior upon irradiation with light was examined and light triggered reversible bundling and precipitation are shown

Chiral selectivity of polyglycerol-based amphiphiles incorporating different aromatic cores

Customized polyglycerol-based surfactants incorporating different aromatic cores are used to isolate and suspend carbon nanotubes in water. Different cores yield suspension with distinct chiral species distribution. Increasing the number of the phenyl rings connecting head and tail, the dispersion of the semiconducting species becomes sharper toward the nanotubes with bigger family index

Carbon nanotube chirality enrichment through chirality-selective precipitation

The interaction with surfactants changes from one carbon nanotube species to the other. We used this to replace non-ionic surfactants by ionic ones. By fine-tuning the replacement conditions, we covered some specific nanotubes with non-ionic surfactants and the others with ionic ones. Addition of salt triggers precipitation of the species suspended by the ionic surfactant; this effectively leads to chiral selective enrichment of a carbon nanotube suspension. We hence produce an (8,4)-enriched suspension by replacing a polyglycerol-based custom amphiphile with the commercial SDBS and salting with NaCl

α-Diimine–Palladium Complexes Incorporated in Vinylic- Addition Polynorbornenes: Synthesis and Catalytic Activity

Producción Científicaα-Diimine polymeric ligands have been synthesized using the bicyclic norbornane structure, present in vinylic-addi- tion polynorbornene ( VA-PNB). The VA-PNB–diimine ligands have been prepared by functionalization of the copolymer ob- tained by Ni-catalyzed polymerization of norbornene and nor- bornenylcarbonate. Immobilized palladium complexes of the type VA-PNB–diimine–PdX2 have been prepared, and their cata- lytic activity has been tested. The trifluoroacetato complex (X =CF3COO) can be used as a recyclable precatalyst in the Suzuki reaction. It is the source of minute amounts of homogeneous palladium active species, which carry out the catalysis with high turnover numbers. The recovered polymeric complex can be reused several times with no significant loss of activity. The polymeric analogue to Brookhart's catalyst, VA-PNB–diimine– PdMeCl, can also polymerize ethylene, although it is less active than its monomeric counterparts.MINECO-SGPI, grant CTQ2013-48406-PMINECO-SGPI, grant CTQ2016-80913-PJunta de Castilla y León, grant VA302U1

Molecular Motion and Performance Enhancement of BORAZAN Fluorescent Dyes

The preparation of three 2,6-dipyrazolyl-4-X-anilines, H(pz2AnX) (X = p-CF3, Cl, tBu) using CuI-catalyzed amination is described. Subsequent reactions of H(pz2AnX) with triphenylboron proceeds with benzene elimination to give the corresponding Ph2B(pz2AnX) compounds in high yields. The Ph2B(pz2AnX) are more highly emissive in the solid state than the previously reported BORAZAN fluorophores, Ph2B(pzAnX), their monopyrazolyl counterparts. As with the Ph2B(pzAnX), the color of emission in Ph2B(pz2AnX) can be tuned simply by varying the para-aniline substituent where the emission of Ph2B(pz2AnX) is red-shifted relative to the corresponding Ph2B(pzAnX) derivatives. The electronic properties were studied by cyclic voltammetry and electronic absorption/emission spectroscopy as well as by density functional calculations (B3LYP/6-31G*). The di-pyrazolyl derivatives exhibit greater stability toward solvolysis and higher photoluminescent quantum yields (despite the red-shift in emission) compared to their monopyrazolyl counterparts presumably due to kinetic stabilization of the chromophore imparted by the second pyrazolyl ligand. For Ph2B(pz2AnX), evidence for intramolecular motion of the diphenylboryl moiety traversing both pyrazolyl groups was detected by variable temperature 1H NMR spectroscopy. The rate increases with increasing electron-donor abilities of the para-aniline substituent

Refractory migraine in a headache clinic population

<p>Abstract</p> <p>Background</p> <p>Many migraineurs who seek care in headache clinics are refractory to treatment, despite advances in headache therapies. Epidemiology is poorly characterized, because diagnostic criteria for refractory migraine were not available until recently. We aimed to determine the frequency of refractory migraine in patients attended in the Headache Unit in a tertiary care center, according to recently proposed criteria.</p> <p>Methods</p> <p>The study population consisted of a consecutive sample of 370 patients (60.8% females) with a mean age of 43 years (range 14-86) evaluated for the first time in our headache unit over a one-year period (between October 2008 and October 2009). We recorded information on clinical features, previous treatments, Migraine Disability Assessment Score (MIDAS), and final diagnosis.</p> <p>Results</p> <p>Overall migraine and tension-type headache were found in 46.4% and 20.5% of patients, respectively. Refractory migraine was found in 5.1% of patients. In refractory migraineurs, the mean MIDAS score was 96, and 36.8% were medication-overusers.</p> <p>Conclusions</p> <p>Refractory migraine is a relatively common and very disabling condition between the patients attended in a headache unit. The proposed operational criteria may be useful in identifying those patients who require care in headache units, the selection of candidates for combinations of prophylactic drugs or invasive treatments such as neurostimulation, but also to facilitate clinical studies in this patient group.</p

Occipital peripheral nerve stimulation in the management of chronic intractable occipital neuralgia in a patient with neurofibromatosis type 1: a case report

<p>Abstract</p> <p>Introduction</p> <p>Occipital peripheral nerve stimulation is an interventional pain management therapy that provides beneficial results in the treatment of refractory chronic occipital neuralgia. Herein we present a first-of-its-kind case study of a patient with neurofibromatosis type 1 and bilateral occipital neuralgia treated with occipital peripheral nerve stimulation.</p> <p>Case presentation</p> <p>A 42-year-old Caucasian woman presented with bilateral occipital neuralgia refractory to various conventional treatments, and she was referred for possible treatment with occipital peripheral nerve stimulation. She was found to be a suitable candidate for the procedure, and she underwent implantation of two octapolar stimulating leads and a rechargeable, programmable, implantable generator. The intensity, severity, and frequency of her symptoms resolved by more than 80%, but an infection developed at the implantation site two months after the procedure that required explantation and reimplantation of new stimulating leads three months later. To date she continues to experience symptom resolution of more than 60%.</p> <p>Conclusion</p> <p>These results demonstrate the significance of peripheral nerve stimulation in the management of refractory occipital neuralgias in patients with neurofibromatosis type 1 and the possible role of neurofibromata in the development of occipital neuralgia in these patients.</p