Accuracy and utility of an epigenetic biomarker for smoking in populations with varying rates of false self-report.

Better biomarkers to detect smoking are needed given the tremendous public health burden caused by smoking. Current biomarkers to detect smoking have significant limitations, notably a short half-life for detection and lack of sensitivity for light smokers. These limitations may be particularly problematic in populations with less accurate self-reporting.

Ta(CNDipp) : An Isocyanide Analogue of Hexacarbonyltantalum(0).

Hexakis(2,6-diisopropylphenylisocyanide)tantalum is the first isocyanide analogue of the highly unstable Ta(CO) and represents the only well-defined zerovalent tantalum complex to be prepared by conventional laboratory methods. Two prior examples of homoleptic Ta complexes are known, Ta(benzene) and Ta(dmpe) , dmpe=1,2-bis(dimethylphosphano)ethane, but these have only been accessed via ligand co-condensation with tantalum vapor in a sophisticated metal-atom reactor. Consistent with its 17-electron nature, Ta(CNDipp) undergoes facile one-electron oxidation, reduction, or disproportionation reactions.

Controlling Cooperative CO Adsorption in Diamine-Appended Mg(dobpdc) Metal-Organic Frameworks.

In the transition to a clean-energy future, CO separations will play a critical role in mitigating current greenhouse gas emissions and facilitating conversion to cleaner-burning and renewable fuels. New materials with high selectivities for CO adsorption, large CO removal capacities, and low regeneration energies are needed to achieve these separations efficiently at scale. Here, we present a detailed investigation of nine diamine-appended variants of the metal-organic framework Mg(dobpdc) (dobpdc = 4,4'-dioxidobiphenyl-3,3'-dicarboxylate) that feature step-shaped CO adsorption isotherms resulting from cooperative and reversible insertion of CO into metal-amine bonds to form ammonium carbamate chains.

Electroanalytical Assessment of the Effect of Ni:Fe Stoichiometry and Architectural Expression on the Bifunctional Activity of Nanoscale NiFeOx.

Electrocatalysis of the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) was assessed for a series of Ni-substituted ferrites (NiFeOx, where y = 0.1 to 0.9) as expressed in porous, high-surface-area forms (ambigel and aerogel nanoarchitectures).

Rewriting Electron-Transfer Kinetics at Pyrolytic Carbon Electrodes Decorated with Nanometric Ruthenium Oxide.

Platinum is state-of-the-art for fast electron transfer whereas carbon electrodes, which have semimetal electronic character, typically exhibit slow electron-transfer kinetics. But when we turn to practical electrochemical devices, we turn to carbon. To move energy devices and electro(bio)analytical measurements to a new performance curve requires improved electron-transfer rates at carbon.

Ethylene oligomerization in metal-organic frameworks bearing nickel(ii) 2,2'-bipyridine complexes.

The metal-organic frameworks ZrO(OH)(bpydc) (1; bpydc = 2,2'-bipyridine-5,5'-dicarboxylate) and ZrO(OH)(bpydc)(bpdc) (2; bpdc = biphenyl-4,4'-dicarboxylate) were readily metalated with Ni(DME)Br (DME = dimethoxyethane) to produce the corresponding metalated frameworks 1(NiBr) and 2(NiBr). Both nickel(ii)-containing frameworks catalyze the oligomerization of ethylene in the presence of EtAlCl. In these systems, the pore environment around the active nickel sites significantly influences their selectivity for formation of oligomers over polymer.

Highly effective ammonia removal in a series of Brønsted acidic porous polymers: investigation of chemical and structural variations.

Although a widely used and important industrial gas, ammonia (NH) is also highly toxic and presents a substantial health and environmental hazard. The development of new materials for the effective capture and removal of ammonia is thus of significant interest. The capture of ammonia at ppm-level concentrations relies on strong interactions between the adsorbent and the gas, as demonstrated in a number of zeolites and metal-organic frameworks with Lewis acidic open metal sites.

Longitudinal assessment of excessive daytime sleepiness in early Parkinson's disease.

Background: Excessive daytime sleepiness (EDS) is common and disabling in Parkinson's disease (PD). Predictors of EDS are unclear, and data on biological correlates of EDS in PD are limited. We investigated clinical, imaging and biological variables associated with longitudinal changes in sleepiness in early PD.

Measuring compensation in neurodegeneration using MRI.

Purpose Of Review: Despite signs of cortical and subcortical loss, patients with prodromal and early-stage neurodegenerative disease are able to perform at a level comparable to the normal population. It is presumed that the onset of compensatory processes, that is changes in brain activation within a function-specific network or in the recruitment of a region outside of the task-network, underlies this maintenance of normal performance. However, in most studies to date, increased brain activity is not correlated with indices of both disease and performance and what appears to be compensation could simply be a symptom of neurodegeneration.

Rechargeable nickel-3D zinc batteries: An energy-dense, safer alternative to lithium-ion.

The next generation of high-performance batteries should include alternative chemistries that are inherently safer to operate than nonaqueous lithium-based batteries. Aqueous zinc-based batteries can answer that challenge because monolithic zinc sponge anodes can be cycled in nickel-zinc alkaline cells hundreds to thousands of times without undergoing passivation or macroscale dendrite formation. We demonstrate that the three-dimensional (3D) zinc form-factor elevates the performance of nickel-zinc alkaline cells in three fields of use: (i) >90% theoretical depth of discharge (DOD) in primary (single-use) cells, (ii) >100 high-rate cycles at 40% DOD at lithium-ion-commensurate specific energy, and (iii) the tens of thousands of power-demanding duty cycles required for start-stop microhybrid vehicles.

Performance of van der Waals Corrected Functionals for Guest Adsorption in the M(dobdc) Metal-Organic Frameworks.

Small-molecule binding in metal-organic frameworks (MOFs) can be accurately studied both experimentally and computationally, provided the proper tools are employed. Herein, we compare and contrast properties associated with guest binding by means of density functional theory (DFT) calculations using nine different functionals for the M(dobdc) (dobdc = 2,5-dioxido,1,4-benzenedicarboxylate) series, where M = Mg, Mn, Fe, Co, Ni, Cu, and Zn. Additionally, we perform Quantum Monte Carlo (QMC) calculations for one system to determine if this method can be used to assess the performance of DFT.

Topological length of white matter connections predicts their rate of atrophy in premanifest Huntington's disease.

We lack a mechanistic explanation for the stereotyped pattern of white matter loss seen in Huntington's disease (HD). While the earliest white matter changes are seen around the striatum, within the corpus callosum, and in the posterior white matter tracts, the order in which these changes occur and why these white matter connections are specifically vulnerable is unclear. Here, we use diffusion tractography in a longitudinal cohort of individuals yet to develop clinical symptoms of HD to identify a hierarchy of vulnerability, where the topological length of white matter connections between a brain area and its neighbors predicts the rate of atrophy over 24 months.

A Microporous Amic Acid Polymer for Enhanced Ammonia Capture.

Amic acids, consisting of carboxylic acids and amides, are often utilized as intermediates that can further undergo a dehydration-cyclization step to yield polymeric cyclic imides. Compared with imide-based materials, the presence of Brønsted acidic groups and multiple hydrogen-bond donors and acceptors in materials incorporating amic acids opens up the possibility for a variety of host-guest interactions. Here we report a facile and catalyst-free synthesis of a Brønsted acidic porous poly(amic acid) (PAA) and present its NH uptake properties using gas adsorption and breakthrough measurements.

Operationalizing compensation over time in neurodegenerative disease.

In pre-clinical Huntington's disease, normal behaviour is maintained despite neurodegeneration, suggesting a mechanism of compensation. Gregory, Long . present two mathematical models of compensation over time and their operationalisation for neuroimaging.

Magneto-Structural Correlations in Pseudotetrahedral Forms of the [Co(SPh)] Complex Probed by Magnetometry, MCD Spectroscopy, Advanced EPR Techniques, and ab Initio Electronic Structure Calculations.

The magnetic properties of pseudotetrahedral Co(II) complexes spawned intense interest after (PPh)[Co(SPh)] was shown to be the first mononuclear transition-metal complex displaying slow relaxation of the magnetization in the absence of a direct current magnetic field. However, there are differing reports on its fundamental magnetic spin Hamiltonian (SH) parameters, which arise from inherent experimental challenges in detecting large zero-field splittings. There are also remarkable changes in the SH parameters of [Co(SPh)] upon structural variations, depending on the counterion and crystallization conditions.

Data quality assurance and control in cognitive research: Lessons learned from the PREDICT-HD study.

We discuss the strategies employed in data quality control and quality assurance for the cognitive core of Neurobiological Predictors of Huntington's Disease (PREDICT-HD), a long-term observational study of over 1,000 participants with prodromal Huntington disease. In particular, we provide details regarding the training and continual evaluation of cognitive examiners, methods for error corrections, and strategies to minimize errors in the data. We present five important lessons learned to help other researchers avoid certain assumptions that could potentially lead to inaccuracies in their cognitive data.

Cognitive Control, Learning, and Clinical Motor Ratings Are Most Highly Associated with Basal Ganglia Brain Volumes in the Premanifest Huntington's Disease Phenotype.

Objectives: Huntington's disease (HD) is a debilitating genetic disorder characterized by motor, cognitive and psychiatric abnormalities associated with neuropathological decline. HD pathology is the result of an extended chain of CAG (cytosine, adenine, guanine) trinucleotide repetitions in the HTT gene. Clinical diagnosis of HD requires the presence of an otherwise unexplained extrapyramidal movement disorder in a participant at risk for HD.

A Trinuclear Radical-Bridged Lanthanide Single-Molecule Magnet.

Assembly of the triangular, organic radical-bridged complexes Cp* Ln (μ -HAN) (Cp*=pentamethylcyclopentadienyl; Ln=Gd, Tb, Dy; HAN=hexaazatrinaphthylene) proceeds through the reaction of Cp* Ln(BPh ) with HAN under strongly reducing conditions. Significantly, magnetic susceptibility measurements of these complexes support effective magnetic coupling of all three Ln centers through the HAN radical ligand. Thorough investigation of the Dy congener through both ac susceptibility and dc magnetic relaxation measurements reveals slow relaxation of the magnetization, with an effective thermal relaxation barrier of U =51 cm .

Longitudinal diffusion changes in prodromal and early HD: Evidence of white-matter tract deterioration.

Introduction: Huntington's disease (HD) is a genetic neurodegenerative disorder that primarily affects striatal neurons. Striatal volume loss is present years before clinical diagnosis; however, white matter degradation may also occur prior to diagnosis. Diffusion-weighted imaging (DWI) can measure microstructural changes associated with degeneration that precede macrostructural changes.

Prevention of Poststroke Mortality Using Problem-Solving Therapy or Escitalopram.

Objective: This study re-examined patients from a 1-year randomized controlled double-blind trial of escitalopram, problem-solving therapy (PST), or placebo to prevent depression among patients less than 3 months after a stroke. The objective of the current study was to determine if preventive treatment would predict time to death over 8-10 years of follow-up. Based on the importance of depression in poststoke mortality and a previous study of this population at 18 months' follow-up showing that stopping escitalopram but not PST led to a significant increase in depression, the authors hypothesized that PST would be associated with the longest time to death.

Phenotype Characterization of HD Intermediate Alleles in PREDICT-HD.

Background: Huntington disease (HD) is a neurodegenerative disease caused by a CAG repeat expansion on chromosome 4. Pathology is associated with CAG repeat length. Prior studies examining people in the intermediate allele (IA) range found subtle differences in motor, cognitive, and behavioral domains compared to controls.

Longitudinal beta-binomial modeling using GEE for overdispersed binomial data.

Longitudinal binomial data are frequently generated from multiple questionnaires and assessments in various scientific settings for which the binomial data are often overdispersed. The standard generalized linear mixed effects model may result in severe underestimation of standard errors of estimated regression parameters in such cases and hence potentially bias the statistical inference. In this paper, we propose a longitudinal beta-binomial model for overdispersed binomial data and estimate the regression parameters under a probit model using the generalized estimating equation method.

Validation of a prognostic index for Huntington's disease.

Background: Characterizing progression in Huntington's disease is important for study the natural course and selecting appropriate participants for clinical trials.

Objectives: The aim was to develop a prognostic index for motor diagnosis in Huntington's disease and examine its predictive performance in external observational studies.

Methods: The prediagnosis Neuro-biological Predictors of Huntington's Disease study (N = 945 gene-positive) was used to select a Cox regression model for computing a prognostic index.

Identification of extreme motor phenotypes in Huntington's disease.

The manifestation of motor signs in Huntington's disease (HD) has a well-known inverse relationship with HTT CAG repeat length, but the prediction is far from perfect. The probability of finding disease modifiers is enhanced in individuals with extreme HD phenotypes. We aimed to identify extreme HD motor phenotypes conditional on CAG and age, such as patients with very early or very late onset of motor manifestation.