Di- and Trinuclear Mixed-Valence Copper Amidinate Complexes from Reduction of Iodine

Molecular examples of mixed-valence copper complexes through chemical oxidation are rare but invoked in the mechanism of substrate activation, especially oxygen, in copper-containing enzymes. To examine the cooperative chemistry between two metals in close proximity to each other we began studying the reactivity of a dinuclear Cu(I) amidinate complex. The reaction of [(2,6-Me2C6H3N)2C(H)]2Cu2, 1, with I2 in tetrahydrofuran (THF), CH3CN, and toluene affords three new mixed-valence copper complexes [(2,6-Me2C6H3N)2C(H)]2Cu2(μ2-I3)(THF)2, 2, [(2,6-Me2C6H3N)2C(H)]2Cu2(μ2-I) (NCMe)2, 3, and [(2,6-Me2C6H3N)2C(H)]3Cu3(μ3-I)2, 4, respectively. The first two compounds were characterized by UV-vis and electron paramagnetic resonance spectroscopies, and their molecular structure was determined by X-ray crystallography. Both di- and trinuclear mixed-valence intermediates were characterized for the reaction of compound 1 to compound 4, and the molecular structure of 4 was determined by X-ray crystallography. The electronic structure of each of these complexes was also investigated using density functional theory

Nineteenth annual New England Intercollegiate Geological Excursion: October 12 and 13, 1923, Massachusetts

Locality 1: Cut on Bow Street, south of Turkey Hill, northwest corner of Arlington; Locality 2: Blueberry Mountain, southeast border of Woburn between Woburn and East Woburn; Locality 3: Shore west of West Manchester, on Gloucester branch of the Boston and Maine R.R., third of the way from Beverly to Glouceste

3414 Association of blood pressure and biochemical knee cartilage composition assessed by T2 relaxation time measurements: Data from the Osteoarthritis Initiative

OBJECTIVES/SPECIFIC AIMS: The goal of this study was to investigate the associations of systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP) with knee articular cartilage composition using magnetic resonance imaging (MRI)-based T2 relaxation time measurements in study participants from the Osteoarthritis Initiative (OAI). METHODS/STUDY POPULATION: In this longitudinal study, 1,139 participants from the OAI, a multi-center, observational study of the evolution of knee OA, were selected using the following inclusion criteria: right knee Kellgren Lawrence (KL) score (radiographic classification of OA severity) 0-2 indicating no to mild radiographic OA at baseline, no history of rheumatoid arthritis at baseline, available blood pressure measurements at baseline, available T2 measurements in at least three knee compartments at baseline and 48-month follow-up. Linear regression models were performed using standardized values for SBP, DBP and PP as primary predictors and change in cartilage T2 over 48 months, a measure of cartilage matrix quality and degeneration, as the primary outcome. PP was defined as SBP minus DBP. Change in superficial layer and deep layer cartilage T2, which reflect differences in the laminar organization of knee cartilage T2, were also included as outcomes. Statistical models were adjusted for common risk factors for knee OA (baseline age, sex, BMI, KL score) as well as number of currently used anti-hypertensive medications (AHM) reported at baseline. We included AHMs whose primary indication was the treatment of hypertension including beta blockers, angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARB), thiazides, chlorthalidone, dihydropyridine calcium channel blockers (CCB) and aliskiren. All predictors, outcomes and covariates (except sex) were analyzed as continuous variables. We included interaction terms in the models to evaluate whether the covariates (age, sex, BMI, KL score, number of AHMs) modified the association of SBP, DBP and PP with cartilage T2. RESULTS/ANTICIPATED RESULTS: The average age of all study participants was 58.8 years (SD ± 8.6) with a higher proportion of men (59.4%), average body mass index (BMI) was 28.3 (SD ± 4.5), average SBP was 122.4 (SD ± 15.4) mmHg, average DBP was 75.5 (SD ± 9.6) mmHg and 469 (38.1%) study participants were taking at least one AHM. Higher baseline DBP was significantly associated with a faster increase in global T2 (0.22 [0.10,0.35], P < 0.001), global deep layer T2 (0.20 [0.03,0.36], P < 0.022) and global superficial layer T2 (0.39 [0.20,0.58], P < 0.001). These associations were significant in both unadjusted and the models adjusted for age, sex, BMI and KL score. No significant associations were found between SBP or PP and cartilage T2 and no significant interactions were found between SBP, DBP, PP and the covariates. DISCUSSION/SIGNIFICANCE OF IMPACT: Higher baseline DBP was associated with a faster increase in knee cartilage T2, suggesting accelerated cartilage degeneration. This association was stronger for the superficial layer of knee cartilage T2 compared to the deep layer. Although further basic mechanistic studies are needed to elucidate the underlying pathophysiology of this relationship, these results suggest lowering DBP may influence knee OA

Association of blood pressure with knee cartilage composition and structural knee abnormalities: data from the osteoarthritis initiative.

ObjectiveTo investigate the associations of systolic blood pressure (SBP) and diastolic blood pressure (DBP) with changes in knee cartilage composition and joint structure over 48 months, using magnetic resonance imaging (MRI) data from the Osteoarthritis Initiative (OAI).Materials and methodsA total of 1126 participants with right knee Kellgren-Lawrence (KL) score 0-2 at baseline, no history of rheumatoid arthritis, blood pressure measurements at baseline, and cartilage T2 measurements at baseline and 48 months were selected from the OAI. Cartilage composition was assessed using MRI T2 measurements, including laminar and gray-level co-occurrence matrix texture analyses. Structural knee abnormalities were graded using the whole-organ magnetic resonance imaging score (WORMS). We performed linear regression, adjusting for age, sex, body mass index, physical activity, smoking status, alcohol use, KL score, number of anti-hypertensive medications, and number of nonsteroidal anti-inflammatory drugs.ResultsHigher baseline DBP was associated with greater increases in global T2 (coefficient 0.22 (95% CI 0.09, 0.34), P = 0.004), global superficial layer T2 (coefficient 0.39 (95% CI 0.20, 0.58), P = 0.001), global contrast (coefficient 15.67 (95% CI 8.81, 22.53), P < 0.001), global entropy (coefficient 0.02 (95% CI 0.01, 0.03) P = 0.011), and global variance (coefficient 9.14 (95% CI 5.18, 13.09), P < 0.001). Compared with DBP, the associations of SBP with change in cartilage T2 parameters and WORMS subscores showed estimates of smaller magnitude.ConclusionHigher baseline DBP was associated with higher and more heterogenous cartilage T2 values over 48 months, indicating increased cartilage matrix degenerative changes

Individual and joint trajectories of change in bone, lean mass and physical performance in older men.

BackgroundDeclines in bone, muscle and physical performance are associated with adverse health outcomes in older adults. However, few studies have described concurrent age-related patterns of change in these factors. The purpose of this study was to characterize change in four properties of muscle, physical performance, and bone in a prospective cohort study of older men.MethodsUsing repeated longitudinal data from up to four visits across 6.9 years from up to 4681 men (mean age at baseline 72.7 yrs. ±5.3) participating in the Osteoporotic Fractures in Men (MrOS) Study, we used group-based trajectory models (PROC TRAJ in SAS) to identify age-related patterns of change in four properties of muscle, physical performance, and bone: total hip bone mineral (BMD) density (g/m2) and appendicular lean mass/ht2 (kg/m2), by DXA; grip strength (kg), by hand dynamometry; and walking speed (m/s), by usual walking pace over 6 m. We also described joint trajectories in all pair-wise combinations of these measures. Mean posterior probabilities of placement in each trajectory (or joint membership in latent groups) were used to assess internal reliability of the model. The number of trajectories for each individual factor was limited to three, to ensure that the pair-wise determination of joint trajectories would yield a tractable number of groups as well as model fit considerations.ResultsThe patterns of change identified were generally similar for all measures, with three district groups declining over time at roughly similar rates; joint trajectories revealed similar patterns with no cross-over or convergence between groups. Mean posterior probabilities for all trajectories were similar and consistently above 0.8 indicating reasonable model fit to the data.ConclusionsOur description of trajectories of change with age in bone mineral density, grip strength, walking speed and appendicular lean mass found that groups identified by these methods appeared to have little crossover or convergence of change with age, even when considering joint trajectories of change in these factors

A Statement on the Appropriate Role for Research and Development in Climate Policy

This statement is issued by a group of economists and scientists which met at Stanford University on October 18, 2008 to discuss the role of research and development (R&D) in developing effective policies for addressing the adverse potential consequences of climate change. We believe that climate change is a serious issue that governments need to address. We also believe that research and development needs to be a central part of governments’ strategies for responding to this challenge. Solutions to manage long-term risks will require the development and global deployment of a range of technologies for energy supply and end-use, land-use, agriculture and adaptation that are not currently commercial. A key potential benefit of focused scientific and technological research and development investment is that it could dramatically reduce the cost of restricting greenhouse gas emissions by encouraging the development of more affordable, better performing technologies.