Endoscope-assisted far lateral craniotomy for resection of posterior fossa neurocysticercosis: illustrative case.

Background: Neurocysticercosis is a parasitic infection that commonly affects the ventricles, subarachnoid spaces, and spinal cord of the central nervous system. The authors report an unusual manifestation of purely posterior fossa neurocysticercosis treated with endoscope-assisted open craniotomy for resection.

Observations: A 67-year-old male presented with 2 months of progressive dizziness, gait ataxia, headaches, decreased hearing, and memory impairment.

Anatomy of the Ventricles, Subarachnoid Spaces, and Meninges.

The ventricular system, subarachnoid spaces, and meninges are structures that lend structure, support, and protection to the brain and spinal cord. This article provides a detailed look at the anatomy of the intracranial portions of these structures with a particular focus on neuroimaging methods.

Head and Neck Sarcomas: A Review of Clinical and Imaging Findings Based on the 2013 World Health Organization Classification.

Objective: Head and neck sarcomas are a complex, heterogeneous group of tumors that present a diagnostic challenge to radiologists because they have many overlapping imaging features. The purpose of this article is to review the imaging and clinical features and highlight distinguishing features of head and neck sarcomas.

Conclusion: An understanding of characteristic imaging and clinical features of head and neck sarcomas is important for the radiologist to narrow the differential diagnosis and help guide management.

Suprasellar Ganglioglioma: Expanding the Differential Diagnosis.

This case study describes a young man with symptoms suggestive of the presence of a space-occupying lesion within the cranial cavity. Imaging studies confirmed a lesion in the suprasellar region and surgical intervention to remove the tumor yielded an unexpected diagnosis. Neuroimaging characteristics and histopathology including immunohistochemistry are described.

Gold nanoparticle-initiated free radical oxidations and halogen abstractions.

We report on the use of EPR spectroscopy and spin trapping technique to detect free radical intermediates formed in the presence of gold nanoparticles. Phosphine- and amine-protected gold nanoparticles were found to initiate air oxidation of organic substrates containing active hydrogen atoms, such as amines and phosphine oxides. Nanoparticles protected by stronger bound ligands (e.

The effects of chelating agents on radical generation in alkaline peroxide systems, and the relevance to substrate damage.

A spin-trapping EPR technique has been employed to explore the generation of hydroxyl radicals from reactions between a series of first row transition metal ions and aqueous hydrogen peroxide at pH 10, and with a range of chelating agents (EDTA, DTPMP and the readily biodegradable ligands S,S-EDDS and IDS). In the absence of these chelating agents only Cu(II) generates a significant level of hydroxyl radicals; in their presence with Cu(II) EDTA and IDS give similar behaviour whereas EDDS and DTPMP inhibit hydroxyl radical generation. For Fe(II), EDTA, DTPMP and IDS significantly enhance ( radical)OH production under these conditions whereas EDDS does not.

Dipole-dipole interactions in spin-labeled au nanoparticles as a measure of interspin distances.

A series of Au nanoparticles modified with a nitroxide-functionalized ligand was prepared with a range of spin-label coverage. The X-band EPR spectra of frozen solutions of these nanoparticles showed coverage-dependent line-broadening due to dipole-dipole interactions between spin labels. We developed a methodology to analyze such spectra in terms of geometrical features of the nanoparticles (e.

(N-Benzyl-bis-N',N''-salicylidene)-cis-1,3,5-triaminocyclohexane copper(II): a novel catalyst for the aerobic oxidation of benzyl alcohol.

Reaction of Cu(BF(4))(2).6H(2)O with the N(3)O(2) donor ligand H(2)L (where H(2)L = N-benzyl-N',N''-di-tert-butyl-disalicyl-triaminocyclohexane) results in the formation of a novel Cu(II)L complex, 1. X-Ray crystallography of it shows the Cu(II) centre coordinated by two phenolate oxygens and two imine nitrogens in a distorted square plane with an elongated bond to the amine nitrogen (2.

Formation and reaction of O=MnV species in the oxidation of phenolic substrates with H2O2 catalysed by the dinuclear manganese(IV) 1,4,7-trimethyl-1,4,7-triazacyclononane complex [MnIV2(mu-O)3(TMTACN)2](PF6)2.

The oxidation of phenolic substrates with H2O2 catalysed by [MnIV2(mu-O)3(TMTACN)2](PF6)2 1, (TMTACN, 1,4,7-trimethyl-1,4,7-triazacyclononane) has been investigated by use of ESI mass spectrometry. The role of the phenols as one-electron reductants and as co-ligands in the stabilisation and reaction of an intermediate O=MnV species has been analysed and the presence of a variety of manganese species in solution has been explained. Our results lead to a proposed mechanism for the catalytic oxidation of phenols in this system.

Spin-labelled Au nanoparticles.

A series of Au nanoparticles functionalised with nitroxide spin labels has been prepared and studied by EPR spectroscopy. Samples with low coverage of the spin label were used to investigate the dynamics of the surface-attached labels at different distances from the Au surface. The rotational correlation times of spin labels vary from 10(-10) s to more than 3 x 10(-9) s, depending on the chain length of the label and the surrounding ligand.

EPR and modelling studies of hydrogen-abstraction reactions relevant to polyolefin cross-linking and grafting chemistry.

EPR spectroscopy has been employed to study directly the selectivity of hydrogen-atom abstraction by some alkoxyl radicals from a variety of linear and branched alkanes, as well as linear alkenes, chosen as models for low molecular-weight polyolefin cross-linking systems. In situ thermal and photolytic approaches, as well as spin-trapping, have been employed to provide information relating to an accessible temperature range of 233-453 K. in part to mimic conditions relevant to melt processing of polyolefins.

Azo dye oxidation with hydrogen peroxide catalysed by manganese 1,4,7-triazacyclononane complexes in aqueous solution.

A kinetic and mechanistic study is reported of the oxidation of a number of azonaphthol dyes with hydrogen peroxide in aqueous solution, catalysed by some mono and dinuclear manganese(IV) complexes of 1,4,7-trimethyl-1,4,7-triazacyclononane (Me3TACN). The results of UV-Vis investigations, augmented by EPR and ESI-MS studies, are described for a series of experiments in which concentrations, pH and ionic strength have been varied. The reactions are characterised by an induction period followed by a relatively rapid oxidation.

Observation of protein-derived (BSA) oxygen-centered radicals by EPR spin-trapping techniques.

Electron paramagnetic resonance (EPR) spin-trapping experiments, employing the novel spin-trap DEPMPO, provide evidence for the formation of protein-peroxyl radicals from the reaction of bovine serum albumin (BSA) or lysozyme with HO. in the presence of O2. Spin-trapping leads to the detection of anisotropic spectra of partially immobilized protein-peroxyl spin-adducts; positive identification is based on a novel spectrum simulation approach (through which broadened anisotropic spectra are simulated and compared with experiment) and by comparison of results with those obtained when MeO2.

EPR study of a place-exchange reaction on Au nanoparticles: two branches of a disulfide molecule do not adsorb adjacent to each other.

An EPR study of a place-exchange reaction of a diradical disulfide with butanethiol-protected Au nanoparticles showed that the two branches of the disulfide molecule do not adsorb adjacent to each other on the Au surface. The most likely mechanism includes adsorption of only one branch of the disulfide molecule in the exchange process. The exchange reaction was found to be zeroth-order with respect to the diradical, indicative of a dissociative "SN1"-type mechanism.