Generalised cerebral atrophy following temporal lobectomy for intractable epilepsy associated with mesial temporal sclerosis

Studies of post-operative imaging data have mainly concentrated on brain atrophy following radiotherapy and/or chemotherapy. We have investigated the effect of conventional surgery on the unresected brain tissue based on the comparison of magnetic resonance images acquired pre- and post-operatively in 13 subjects with a history of mesio-temporal epilepsy. The pre- and post-operative scans were co-registered prior to volumetric analysis. The total brain volume (TBV) was calculated by semi-automated segmentation, and the total volume loss was the difference between the post-operative and pre-operative TBV. The total volume of resection was determined by manual delineation in the post-operative scan. The atrophy volume in the post-operative scan was calculated as the difference between the total volume loss and the resection volume. In 6 cases, there was generalised cerebral atrophy of the order 4-5% of the total brain volume. In addition to the automated volumetric technique, the images were assessed by two expert neuroradiologists. There was complete correspondence between their assessment and the automated technique. The causes and significance of this phenomenon are unknown but it requires further investigation as it may be related to seizure control and neuropsychological changes following epilepsy surgery.     

Color Tunable Emission and Oxygen Sensing from a Discrete Europium−Pyrene Assembly

We report the synthesis of a new pyrene, dipicolinic acid-based ligand ( L₁H ) and its corresponding multi-emissive and multifunctional europium complex [Eu( L₁ )₃] that is capable of single component color switchable emission from red to blue and also white. At high concentration (10 mM) the single component system results in near pure white emission (CIE coordinates x,y=0.329, 0.324). Furthermore, the system showed ratiometric oxygen sensing with oxygen significantly quenching the pyrene centered emission but not the Eu³⁺ emission, resulting in an overall emission color change from blue to red on increasing oxygen content.     

Production of monodisperse cerium oxide microspheres with diameters near 100 µm by internal-gelation sol–gel methods

Internal-gelation sol–gel methods have used a variety of sphere-forming methods in the past to produce metal oxide microspheres, but typically with poor control over the size uniformity at diameters near 100?µm. This work describes efforts to make and measure internal-gelation, sol–gel microspheres with very uniform diameters in the 100–200-µm size range using a two-fluid nozzle. A custom apparatus was used to form aqueous droplets of sol–gel feed solutions in silicone oil and heat them to cause gelation of the spheres. Gelled spheres were washed, dried, and sintered prior to mounting them on glass slides for optical imaging and analysis. Microsphere diameters and shape factors were determined as a function of silicone oil flow rate in a two-fluid nozzle and the size of a needle dispensing the aqueous sol–gel solution. Nine batches of microspheres were analyzed and had diameters ranging from 65.5?±?2.4?µm for the smallest needle and the fastest silicone oil flow rate to 211?±?4.7?µm for the largest needle and the slowest silicone oil flow rate. Standard deviations for measured diameters were less than 8% for all samples and most of them were less than 4%. Microspheres had excellent circularity with measured shape factors of 0.9–1. However, processing of optical images was complicated by shadow effects in the photoresist layer on glass slides and by overlapping microspheres. Based on the calculated flow parameters, microspheres were produced in a simple dripping mode in the two-fluid nozzle. Using flow rates consistent with a simple dripping mode in a two-fluid nozzle configuration allows for very uniform oxide microspheres to be produced using the internal-gelation sol–gel method.

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Introduction of the Impulse Response Function in Common-Path Interferometers with Fourier Plane Filters

In the present paper it will be shown how the introduction of a Fourier plane filter can create various types of common-path interferometers for measuring changes in surface tilt or curvature of an object surface. This is obtained by placing a holographic optical element in the Fourier plane of a 4-f optical system. The interferometers are analysed by using the paraxial approximation of the Huygens-Fresnel integral formalism, and the interferometer functions are given by a novel formalism using impulse response functions. Based on this technique, an interferometer for measuring dedicated changes in surface deflection is presented. This interferometer is insensitive to rigid surface rotations and displacements. The interferometer can be embedded in systems based on single point measurement of a time dependent deflection, i.e. vibrometers, as well as in full-field measurements such as electronic speckle interferometers.This paper was originally presented at the 2001 International Conference (2nd Joint OSJ-SPIE Conference) on Optical Engineering for Sensing and Nanotechnology, ICOSN 2001 which was held June 6-8, 2001 at the Pacifico-Yokohama Conference Center, Yokohama, Japan.     

High and low spin mononuclear and dinuclear iron(II) complexes of 4-amino and 4-pyrrolyl-3,5-di(2-pyridyl)-4H-1,2,4-triazoles

The first dinuclear iron(II) complexes of any 4-substituted 3,5-di(2-pyridyl)-4H-1,2,4-triazole ligands, [Fe(II)2(adpt)2(H2O)1.5(CH3CN)2.5](BF4)4 and [Fe(II)2(pldpt)2(H2O)2(CH3CN)2](BF4)4, are presented [where adpt is 4-amino-3,5-di(2-pyridyl)-4H-1,2,4-triazole and pldpt is 4-pyrrolyl-3,5-di(2-pyridyl)-4H-1,2,4-triazole]. Both dinuclear complexes feature doubly triazole bridged iron(II) centers that are found to be [high spin-high spin] at all temperatures, 4-300 K, and to exhibit weak antiferromagnetic coupling. In the analogous monometallic complexes, [Fe(II)(Rdpt)2(X)2](n+), the spin state of the iron(II) center was controlled by appropriate selection of the axial ligands X. Specifically, both of the chloride complexes, [Fe(II)(adpt)2(Cl)2] x 2 MeOH and [Fe(II)(pldpt)2(Cl)2] x 2 MeOH x H2O, were found to be high spin whereas the pyridine adduct [Fe(II)(adpt)2(py)2](BF4)2 was low spin. Attempts to prepare [Fe(II)(pldpt)2(py)2](BF4)2 and the dinuclear analogues [Fe(II)2(Rdpt)2(py)4](BF4)4 failed, illustrating the significant challenges faced in attempts to develop control over the nature of the product obtained from reactions of iron(II) and these bis-bidentate ligands.     

Delayed lanthanide luminescent Tb(III) complexes formed from lower rim amide functionalised calix[4]arenes

The synthesis and the photophysical studies of a new generation of time resolved luminescent systems based on calix[4]arenes alkylated at the lower rim, capable of hosting lanthanide (III) ions such as terbium and sensitising its emission, are described. Two series of ligands were designed to provide an ideal cavity to host terbium (Tb(III)) and were synthesised in high yields following two novel approaches. The tetra-alkylation, which was achieved in one step using with piperidino- and morpholino-acetamide pendant arms, provides eight donor atoms forming a binding ‘pocket’ at an ideal distance from the metal core to favour the sensitisation via the antenna effect. Of the two ligand series developed, compounds 3 and 4 possess a short spacer between the calix and the amide receptor site. The second series of ligands 6–7, designed with longer pendant amide arms, was synthesised from 2 in two steps through the ester analogue 5. The crystal structure of 3 (and 6 as shown in Supporting Information, available online) is presented. The synthesis and the photophysical studies of the four resulting complexes 3.Tb, 4.Tb, 6.Tb and 7.Tb are described in detail and in each case, successful sensitisation of the terbium emission occurred upon excitation of the phenolic scaffold of the calixarene.     

Characterisation of N‐(Octadecyl)‐1,8‐naphthalimide Monolayer Compression Using Molecular Dynamics and Experimental Approaches

The development of luminescent surfaces is an active area of supramolecular chemistry, particularly for the development of new sensing platforms. One particularly useful surface deposition method is the Langmuir–Blodgett technique where organic amphiphilic fluorophores (e.g. 1,8‐naphthalimides) can form ordered monolayers at an air–water interface before being deposited onto solid supports. The ability to simulate monolayer formation and consequently develop predictability over film formation would allow for significant advances in the luminescent materials field where synthesis might be directed by simulation data. Here, we compare pressure‐area isotherms of N‐(octadecyl)‐1,8‐naphthalimide determined experimentally, using the Langmuir–Blodgett technique, and computationally, using three different simulation techniques. We find that all three simulation techniques are able to describe the liquid‐condensed/liquid‐expanded region of the isotherm, and that the isotherms are highly similar in this region, although the NγT ensemble performs best. Experimental isotherms showed film formation properties that align with the simulation data, suggesting that simulations are a viable means to direct synthesis. Investigation of the underlying structural details disclosed by the simulations reveals the compression‐induced ordering at atomic‐level detail, which will allow prediction of how functionalisation of the naphthalimides will alter the monolayer compression and mounting process.