95 research outputs found
4,4-Bis(4-methylÂphenylÂsulfanÂyl)-1,1-diphenyl-2-azaÂbuta-1,3-diene
In the title compound, C29H25NS2, both the Cl atoms of the azaÂdiene precursor 4,4-dichloro-1,1-diphenyl-2-azaÂbuta-1,3-diene are replaced by two vicinal S-p-tolyl substituents attached to the terminal C atom of a Ï€-conjugated 2-azaÂbutadiene array. The azaÂdiene chain is planar to within 0.01 Å. One of the phenyl rings seems to be slightly Ï€-conjugated with the azaÂdiene core [dihedral angle 5.1 (2)°]
Structural diversity in the borohydrido lanthanides series: first isolation and X Ray crystal structure of ionic [Sm(BH4)2(THF)5]+[Cp*'Sm(BH4)3]-
International audienceTwo new borohydrido complexes of samarium were prepared: [Sm(BH4)2(THF)5]+[Cp*'Sm(BH4)3]- (1) and Cp*'2Sm(BH4)(THF) (3) (Cp*' = C5Me4nPr). X Ray studies revealed that 1 displays an unprecedented ionic structure comprising a half samarocene moiety, whereas 3 is monomeric and bears a terminal BH4 ligand
Synthesis, Structure of Nitrogen-Containing Phosphinogold(I) Ferrocenes. In vitro Activity against Bladder and Colon Carcinoma Cell Lines
The gold salt [(tht)AuCl] was reacted with [1-N,N-dimethylaminométhyl-2-diphenylphosphino]ferrocene (1) forming the bimetallic derivative 4. The reaction of methyl iodide
and tetramethylammonium bromide on the chloride 4 produced the ammonium salt 5 and the
bromide 6 respectively. New aminophosphines 2 and 3, which represent two of the rare
phosphorylated metallocenes containing P(III)-N bond have also been coordinated to gold(I) to
form 7 and 8. The presence of the ethoxy group in 7 provides evidence for the lability of one
nitrogen-phosphorus bond. The X-ray structure of compounds 4 and 7 have been established.
Both crystallize in space group P21/c, monoclinic, with a = 11.095(2) Ã…, b = 12.030(3) Ã…, c =
17.763(4) Å, β= 94.02(2)∘, Z = 4 for 4 and a = 14.863(3) Å, b = 8.036(5)Å, c = 18.062(5)Å, β =101.64(1)°, Z = 4 for 7. 197Au Mössbauer data are in good agreement with those for other linear P-Au-Cl containing complexes. The compounds were evaluated for in vitro anti-tumour activity
against two human tumours. Differential cytotoxicity was observed with activity comparable to
cisplatin, with the exception of one compound which was significantly more cytotoxic
Excitation-wavelength Dependent Fluorescence of Ethyl 5-(4-aminophenyl)-3-amino-2,4-dicyanobenzoate
The excitation wavelength dependence of the steady-state and time-resolved emission spectra of ethyl 5-(4-aminophenyl)-3-amino-2,4-dicyanobenzoate (EAADCy) in tetrahydrofuran (THF) at room temperature has been examined. It is found that the ratio of the fluorescence intensity of the long-wavelength and short-wavelength fluorescence bands strongly depends on the excitation wavelength, whereas the wavelengths of the fluorescence excitation and fluorescence bands maxima are independent on the observation/excitation wavelengths. The dynamic Stokes shift of fluorophore in locally excited (LE) and intramolecular charge transfer (ICT) states has been studied with a time resolution about 30Â ps. The difference between Stokes shift in the LE and ICT states was attributed to the solvent response to the large photoinduced dipole moment of EAADCy in the fluorescent charge transfer state. On this base we can state that, the relaxation of the polar solvent molecules around the fluorophore was observed
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Predicting inter-hemispheric transfer time from the diffusion properties of the corpus callosum in healthy individuals and schizophrenia patients: A combined ERP and DTI study
Background—Several theories of schizophrenia have emphasized the role of aberrant neural timing in the etiology of the disease, possibly as a consequence of conduction delays caused by structural damage to the white-matter fasciculi. Consistent with this theory, increased interhemispheric transmission times (IHTTs) to unilaterally-presented visual stimuli have been reported in patients with schizophrenia. The present study investigated whether or not these IHTT abnormalities could be underpinned by structural damage to the visual fibers of the corpus callosum. Methods—30 schizophrenia patients and 22 matched controls underwent Event Related Potential (ERP) recording, and a subset of 19 patients and 16 controls also underwent 3T Diffusion-Tensor Imaging (DTI). Unilateral visual stimuli (squares, 2 × 2 degrees) were presented 6 degrees lateral to either side of a central fixation point. IHTTs (ipsilateral minus contralateral latencies) were calculated for the P1 and N1 components at occipital-temporal sites in current source densitytransformed ERPs. The visual fibers of the corpus callosum were extracted with streamline tractography and the diffusion metrics of Fractional Anisotropy (FA) and Mode calculated. Results—While both subject groups exhibited highly significant IHTTs across a range of posterior electrode pairs, and significantly shorter IHTTs from left-to-right hemisphere than vice versa, no significant groupwise differences in IHTT were observed. However, participants’ IHTTs were linearly related to their FA and Mode, with longer IHTTs being associated with lower FA and more prolate diffusion ellipsoids. Conclusions—These results suggest that IHTTs are estimable from DTI measures of white matter integrity. In light of the range of diffusion abnormalities that have been reported in patients with schizophrenia, particularly in frontal fasciculi, these results support the conjecture that schizophrenia is ultimately underpinned by abnormalities in neural timing
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The uncinate fasciculus and extraversion in schizotypal personality disorder: A diffusion tensor imaging study
Psycholog
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Electrophysiological and diffusion tensor imaging evidence of delayed corollary discharges in patients with schizophrenia
Patients with schizophrenia (SZ) characteristically exhibit supranormal levels of cortical activity to self-induced sensory stimuli, ostensibly because of abnormalities in the neural signals (corollary discharges, CDs) normatively involved in suppressing the sensory consequences of self-generated actions. The nature of these abnormalities is unknown. This study investigated whether SZ patients experience CDs that are abnormally delayed in their arrival at the sensory cortex. Twentyone patients with SZ and 25 matched control participants underwent electroencephalography (EEG). Participants’ level of cortical suppression was calculated as the amplitude of the N1 component evoked by a button press-elicited auditory stimulus, subtracted from the N1 amplitude evoked by the same stimulus presented passively. In the three experimental conditions, the auditory stimulus was delivered 0, 50 or 100 ms subsequent to the button-press. Fifteen SZ patients and 17 healthy controls (HCs) also underwent diffusion tensor imaging (DTI), and the fractional anisotropy (FA) of participants’ arcuate fasciculus was used to predict their level of cortical suppression in the three conditions. While the SZ patients exhibited subnormal N1 suppression to undelayed, self-generated auditory stimuli, these deficits were eliminated by imposing a 50-ms, but not a 100-ms, delay between the button-press and the evoked stimulus. Furthermore, the extent to which the 50-ms delay normalized a patient’s level of N1 suppression was linearly related to the FA of their arcuate fasciculus. These data suggest that SZ patients experience temporally delayed CDs to self-generated auditory stimuli, putatively because of structural damage to the white-matter (WM) fasciculus connecting the sites of discharge initiation and destination
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