Functional MRI connectivity as a predictor of the surgical outcome of epilepsy.

Purpose: In planning epilepsy surgery, it is important to be able to assess the likelihood of success of surgery for each patient so that the possible risk and benefit can be properly considered. In this study, functional connectivity was investigated as a means for predicting surgical outcome from the preoperative functional magnetic resonance imaging (fMRI) of epilepsy patients.

Methods: Resting-state simultaneous electroencephalography (EEG)-fMRI data were collected from 18 patients with intractable epilepsy before surgery and from 14 healthy subjects.

A whole-brain voxel based measure of intrinsic connectivity contrast reveals local changes in tissue connectivity with anesthetic without a priori assumptions on thresholds or regions of interest.

The analysis of spontaneous fluctuations of functional magnetic resonance imaging (fMRI) signals has recently gained attention as a powerful tool for investigating brain circuits in a non-invasive manner. Correlation-based connectivity analysis investigates the correlations of spontaneous fluctuations of the fMRI signal either between a single seed region of interest (ROI) and the rest of the brain or between multiple ROIs. To do this, a priori knowledge is required for defining the ROI(s) and without such knowledge functional connectivity fMRI cannot be used as an exploratory tool for investigating the functional organization of the brain and its modulation under different conditions.

Spin dephasing under nonlinear gradients: implications for imaging and field mapping.

This work examines the prototypical MR echo that would be expected for a voxel of spins evolving in a strong nonlinear field, specifically focusing on the quadratic z(2) - ½(x(2) + y(2) ) field. Dephasing under nonlinear gradients is increasingly relevant given the growing interest in nonlinear imaging, and here, we report several notable differences from the linear case. Most notably, in addition to signal loss, intravoxel dephasing under gradients creating a wide and asymmetric frequency distribution across the voxel can cause skewed and nonlinear phase evolution.

Resting functional connectivity between the hemispheres in childhood absence epilepsy.

Objective: The fundamental mechanisms by which childhood absence epilepsy (CAE) changes neural networks even between seizures remain poorly understood. During seizures, cortical and subcortical networks exhibit bihemspheric synchronous activity based on prior EEG-fMRI studies. Our aim was to investigate whether this abnormal bisynchrony may extend to the interictal period, using a blood oxygen level-dependent (BOLD) resting functional connectivity approach.

Social network theory applied to resting-state fMRI connectivity data in the identification of epilepsy networks with iterative feature selection.

Epilepsy is a brain disorder usually associated with abnormal cortical and/or subcortical functional networks. Exploration of the abnormal network properties and localization of the brain regions involved in human epilepsy networks are critical for both the understanding of the epilepsy networks and planning therapeutic strategies. Currently, most localization of seizure networks come from ictal EEG observations.

Reduced genual corpus callosal white matter integrity in pathological gambling and its relationship to alcohol abuse or dependence.

Objective: Magnetic resonance imaging (MRI) studies have demonstrated functional prefrontal cortical (PFC) abnormalities in pathological gambling (PG) and other psychiatric disorders characterized by impaired impulse control; e.g., cocaine dependence and bipolar disorder.

Water-soluble alkylated bis{4'-(4-pyridyl)-2,2':6',2''-terpyridine}ruthenium(II) complexes for use as photosensitizers in water oxidation: a complementary experimental and TD-DFT investigation.

A series of N-alkylated derivatives [RuL(2)][PF(6)](4) has been prepared from [Ru(pytpy)(2)][PF(6)](2) (N-alkyl substituent = 4-cyanobenzyl, 4-nitrobenzyl, ethyl, cyanomethyl, allyl, octyl). Solution NMR spectroscopic, electrochemical and photophysical properties are reported, along with the single crystal structure of [Ru(4)(2)][PF(6)](4)·H(2)O (4 = 4'-(4-(1-ethylpyridinio))-2,2':6',2'-terpyridine). Anion exchange leads to the water-soluble [RuL(2)][HSO(4)](4) salts (N-alkyl substituent = benzyl, 4-cyanobenzyl, 4-nitrobenzyl, ethyl, cyanomethyl, allyl, octyl) and the NMR spectroscopic signatures of pairs of hexafluoridophosphate and hydrogensulfate salts are compared.

Impaired attention and network connectivity in childhood absence epilepsy.

Patients with childhood absence epilepsy (CAE) often demonstrate impaired interictal attention, even with control of their seizures. No previous study has investigated the brain networks involved in this impairment. We used the continuous performance task (CPT) of attentional vigilance and the repetitive tapping task (RTT), a control motor task, to examine interictal attention in 26 children with CAE and 22 matched healthy controls.

Periparturient effects of feeding a low dietary cation-anion difference diet on acid-base, calcium, and phosphorus homeostasis and on intravenous glucose tolerance test in high-producing dairy cows.

Feeding rations with low dietary cation-anion difference (DCAD) to dairy cows during late gestation is a common strategy to prevent periparturient hypocalcemia. Although the efficacy of low-DCAD rations in reducing the incidence of clinical hypocalcemia is well documented, potentially deleterious effects have not been explored in detail. The objective of the study presented here was to determine the effect of fully compensated metabolic acidosis on calcium and phosphorus homeostasis, insulin responsiveness, and insulin sensitivity as well as on protein metabolism.

Microstructural and functional connectivity in the developing preterm brain.

Prematurely born children are at increased risk for cognitive deficits, but the neurobiological basis of these findings remains poorly understood. Because variations in neural circuitry may influence performance on cognitive tasks, recent investigations have explored the impact of preterm birth on connectivity in the developing brain. Diffusion tensor imaging studies demonstrate widespread alterations in fractional anisotropy, a measure of axonal integrity and microstructural connectivity, throughout the developing preterm brain.

When is a metallopolymer not a metallopolymer? When it is a metallomacrocycle.

We report reactions of cobalt(II) acetate with a series of ditopic bis(tpy) ligands (tpy = 2,2':6',2''-terpyridine) containing flexible polyethyleneoxy spacers (tpy-4'-O{(CH(2))(2)O}(n)-4'-tpy, n = 2, 3, 4 or 6 ligands 1-4, respectively) which result in the formation of complicated mixtures of species, presumed to be both open chain and cyclic species. Well resolved paramagnetically shifted (1)H NMR spectra are a powerful tool for the analysis of these solution systems. Upon equilibration, [n + n] metallomacrocycles are isolated as the dominant (thermodynamic) species in some cases, and the single crystal X-ray structures of [Co(2)(3)(2)][PF(6)](4)·6MeCN and [Co(2)(4)(2)][PF(6)](5)·2MeCN (a mixed cobalt(ii)/cobalt(iii) species) are presented.

Biofeedback of real-time functional magnetic resonance imaging data from the supplementary motor area reduces functional connectivity to subcortical regions.

Recent studies have reported that biofeedback of real-time functional magnetic resonance imaging data can enable people to gain control of activity in specific parts of their brain and can alter functional connectivity between brain areas. Here we describe a study using biofeedback of real-time functional magnetic resonance imaging data to train healthy subjects to control activity in their supplementary motor area (SMA), a region of interest in Tourette syndrome (TS). Although a significant increase in control over the SMA during biofeedback was not found, subjects were able to exert significant control over the SMA in later biofeedback sessions despite not having control in the first biofeedback session.

STORC safety initiative: a multicentre survey on preparedness & confidence in obstetric emergencies.

Background: Patient safety is a national and international priority. The purpose of this study was to understand clinicians' perceptions of teamwork during obstetric emergencies in clinical practice, to examine factors associated with confidence in responding to obstetric emergencies and to evaluate perceptions about the value of team training to improve preparedness.

Methods: An anonymous survey was administered to all clinical staff members who respond to obstetric emergencies in seven Oregon hospitals from June 2006 to August 2006.

Preterm birth results in alterations in neural connectivity at age 16 years.

Very low birth weight preterm (PT) children are at high risk for brain injury. Employing diffusion tensor imaging (DTI), we tested the hypothesis that PT adolescents would demonstrate microstructural white matter disorganization relative to term controls at 16 years of age. Forty-four PT subjects (600-1250 g birth weight) without neonatal brain injury and 41 term controls were evaluated at age 16 years with DTI, the Wechsler Intelligence Scale for Children-III (WISC), the Peabody Picture Vocabulary Test-Revised (PPVT), and the Comprehensive Test of Phonological Processing (CTOPP).

Towards catenanes using π-stacking interactions and their influence on the spin-state of a bis(2,2':6',2"terpyridine)iron(II) domain.

The ligand 6,6"bis(4-methoxyphenyl)-4'-phenyl-2,2':6',2"terpyridine (2) has been prepared and characterized; deprotection using pyridinium chloride leads to the formation of 6,6"bis(4-hydroxyphenyl)-4'-phenyl-2,2':6',2"terpyridinium chloride ([H3]Cl). Treatment of the latter with 3-(2-(2-bromoethoxy)ethoxy)prop-1-ene under basic conditions yields ligand 4 containing pendant, alkene-terminated chains. Whereas direct complexation of 4 with ruthenium(II) proved problematical, the homoleptic complexes [Fe(2)(2)][PF(6)](2) and [Ru(2)(2)][PF(6)](2) were prepared in good to moderate yields.

Effect of colostral volume, interval between calving and first milking, and photoperiod on colostral IgG concentrations in dairy cows.

Objective: To identify cow and management factors associated with colostral IgG concentration in dairy cows.

Design: Prospective observational study.

Animals: 81 multiparous Holstein-Friesian cows from a single herd.

Short communication: Inadequate vitamin D exacerbates parathyroid hormone elevations in tenofovir users.

Parathyroid hormone (PTH) elevations are associated with reduced bone mineral density and adverse health outcomes and have been reported in patients with HIV infection. We aimed to examine the impact of vitamin D status and tenofovir (TDF) use on PTH levels among HIV-infected patients receiving combination antiretroviral therapy (cART). Demographics, medication and supplement use, and clinical data, including 25-hydroxyvitamin D [25(OH)D] and PTH, were collected on 45 HIV-infected men on ART.

O-space imaging: Highly efficient parallel imaging using second-order nonlinear fields as encoding gradients with no phase encoding.

Recent improvements in parallel imaging have been driven by the use of greater numbers of independent surface coils placed so as to minimize aliasing along the phase-encode direction(s). However, gains from increasing the number of coils diminish as coil coupling problems begin to dominate and the ratio of acceleration gain to expense for multiple receiver chains becomes prohibitive. In this work, we redesign the spatial-encoding strategy in order to gain efficiency, achieving a gradient encoding scheme that is complementary to the spatial encoding provided by the receiver coils.

Organization of central synapses by adhesion molecules.

Synapses are the primary means for transmitting information from one neuron to the next. They are formed during the development of the nervous system, and the formation of appropriate synapses is crucial for the establishment of neuronal circuits that underlie behavior and cognition. Understanding how synapses form and are maintained will allow us to address developmental disorders such as autism, mental retardation and possibly also psychological disorders.

Simultaneous EEG, fMRI, and behavior in typical childhood absence seizures.

Purpose: Absence seizures cause transient impairment of consciousness. Typical absence seizures occur in children, and are accompanied by 3-4-Hz spike-wave discharges (SWDs) on electroencephalography (EEG). Prior EEG-functional magnetic resonance imaging (fMRI) studies of SWDs have shown a network of cortical and subcortical changes during these electrical events.

Liposomal amphotericin B and echinocandins as monotherapy or sequential or concomitant therapy in murine disseminated and pulmonary Aspergillus fumigatus infections.

Monotherapy and combination therapy were compared using optimal doses of liposomal amphotericin B, micafungin, or caspofungin in Aspergillus fumigatus pulmonary and disseminated infections. Mice were challenged intravenously (2.8 x 10(4) to 5.

Mix and match: templating chiral Schiff base ligands to suit the needs of the metal ion.

One-pot reactions of 2,2'-bipyridine-6-carbaldehyde, (1S,2S)-(-)-1,2-diphenyl-1,2-diaminoethane and FeCl(2).4H(2)O or Zn(OAc)(2).2H(2)O (2 : 1 : 1) at room temperature in MeOH lead to [Fe{(S,S)-5}(2)][PF(6)]Cl or [Zn{(S,S)-5}(2)][PF(6)](2) in which (S,S)-5 contains an imidazolidine ring, produced by intramolecular cyclization.

Dynamic time course of typical childhood absence seizures: EEG, behavior, and functional magnetic resonance imaging.

Absence seizures are 5-10 s episodes of impaired consciousness accompanied by 3-4 Hz generalized spike-and-wave discharge on electroencephalography (EEG). The time course of functional magnetic resonance imaging (fMRI) changes in absence seizures in relation to EEG and behavior is not known. We acquired simultaneous EEG-fMRI in 88 typical childhood absence seizures from nine pediatric patients.

Functional connectivity between task-positive and task-negative brain areas and its relation to working memory performance.

Functional brain imaging studies have identified a set of brain areas typically activated during cognitive tasks (task-positive brain areas) and another set of brain areas typically deactivated during cognitive tasks (task-negative brain areas). Negative correlations, or anticorrelations, between task-positive and task-negative brain areas have been reported at rest. Furthermore, the strength of these anticorrelations appears to be related to cognitive function.

Intramolecular pi-stacking in a phenylpyrazole-based iridium complex and its use in light-emitting electrochemical cells.

A novel iridium(III) complex, [Ir(dmppz)(2)pbpy][PF(6)] (Hdmppz = 3,5-dimethyl-1-phenylpyrazole and pbpy = 6-phenyl-(2,2'-bipyridine)), is reported. The complex shows an intramolecular face-to-face pi-stacking between the phenyl ring of the dmppz ligand and the pendant phenyl of the pbpy ligand. This interaction provides a supramolecular cage formation that holds also in the excited states.