Radical Carbon–Carbon Bond Formations Enabled by Visible Light Active Photocatalysts

This mini-review highlights the Stephenson group's contribution to the field of photoredox catalysis with emphasis on carbon–carbon bond formation. The realization of photoredox mediated reductive dehalogenation initiated investigations toward both intra- and intermolecular coupling reactions. These reactions commenced via visible light-mediated reduction of activated halogens to give carbon-centered radicals that were subsequently involved in carbon–carbon bond forming transformations. The developed protocols using Ru and Ir based polypyridyl complexes as photoredox catalysts were further tuned to efficiently catalyze overall redox neutral atom transfer radical addition reactions. Most recently, a simplistic flow reactor technique has been utilized to affect a broad scope of photocatalytic transformations with significant enhancement in reaction efficiency

Extensive collection of femtoliter pad secretion droplets in beetle Leptinotarsa decemlineata allows nanoliter microrheology

Pads of beetles are covered with long, deformable setae, each ending in a micrometric terminal plate coated with secretory fluid. It was recently shown that the layer of the pad secretion covering the terminal plates is responsible for the generation of strong attractive forces. However, less is known about the fluid itself because it is produced in extremely small quantity. We here present a first experimental investigation of the rheological properties of the pad secretion in the Colorado potato beetle {\it Leptinotarsa decemlineata}. Because the secretion is produced in an extremely small amount at the level of the terminal plate, we first develop a procedure based on capillary effects to collect the secretion. We then manage to incorporate micrometric beads, initially in the form of a dry powder, and record their thermal motion to determine the mechanical properties of the surrounding medium. We achieve such a quantitative measurement within the collected volume, much smaller than the $1 {\rm \mu}$l sample volume usually required for this technique. Surprisingly, the beetle secretion was found to behave as a purely viscous liquid, of high viscosity. This suggests that no specific complex fluid behaviour is needed during beetle locomotion. We build a scenario for the contact formation between the spatula at the setal tip and a substrate, during the insect walk. We show that the attachment dynamics of the insect pad computed from the high measured viscosity is in good agreement with observed insect pace. We finally discuss the consequences of the secretion viscosity on the insect adhesion

Balancing the Benefits and Risks of 2 Doses of Dabigatran Compared With Warfarin in Atrial Fibrillation

ObjectivesThis study sought to compare the net clinical benefit of dabigatran 110 mg bid and 150 mg bid with that of warfarin in patients with atrial fibrillation (AF).BackgroundIn patients with AF, dabigatran 110 mg bid and 150 mg bid are associated with similar rates of death. However, the higher dose reduces ischemic stroke and increases bleeding compared with the lower dose. Therefore, there is uncertainty about how to evaluate the overall benefit of the 2 doses.MethodsIn 18,113 AF patients in the RE-LY (Randomized Evaluation of Long Term Anticoagulant Therapy) trial, we used a previously developed method for integrating ischemic and bleeding events as “ischemic stroke equivalents” in order to compare a weighted benefit of 2 doses of dabigatran with each other, and with that of warfarin.ResultsCompared with warfarin, there was a significant decrease in ischemic stroke equivalents with both dabigatran doses: –0.92 per 100 patient years (95% confidence interval [CI]: –1.74 to −0.21, p = 0.02) with dabigatran 110 mg bid and –1.08 (95% CI: –1.86 to −0.34, p = 0.01) with dabigatran 150 mg bid. There was no significant difference in ischemic stroke equivalents between the 2 doses: –0.16 (95% CI: –0.80 to 0.43) comparing dabigatran 150 mg bid with 110 bid. When including death in the weighted benefit calculations, the results were similar.ConclusionsOn a group level both doses of dabigatran as compared with warfarin have similar benefits when considering a weighted estimate including both efficacy and safety. The similar overall benefits of the 2 doses of dabigatran versus warfarin support individualizing the dose based on patient characteristics and physician and patient preferences. (Randomized Evaluation of Long Term Anticoagulant Therapy [RE-LY] With Dabigatran Etexilate; NCT00262600

D-dimer and risk of thromboembolic and bleeding events in patients with atrial fibrillation - observations from the ARISTOTLE trial

BackgroundD-dimer is related to adverse outcomes in arterial and venous thromboembolic diseases. ObjectivesTo evaluate the predictive value of D-dimer level for stroke, other cardiovascular events, and bleeds, in patients with atrial fibrillation (AF) treated with oral anticoagulation with apixaban or warfarin; and to evaluate the relationship between the D-dimer levels at baseline and the treatment effect of apixaban vs. warfarin. MethodsIn the ARISTOTLE trial, 18201 patients with AF were randomized to apixaban or warfarin. D-dimer was analyzed in 14878 patients at randomization. The cohort was separated into two groups; not receiving vitaminK antagonist (VKA) treatment and receiving VKA treatment at randomization. ResultsHigher D-dimer levels were associated with increased frequencies of stroke or systemic embolism (hazard ratio [HR][Q4 vs. Q1]1.72, 95% confidence interval [CI]1.14-2.59, P=0.003), death (HR[Q4 vs. Q1]4.04, 95%CI3.06-5.33) and major bleeding (HR[Q4 vs. Q1]2.47, 95%CI1.77-3.45,

Transcript of The Dory Derby Accident

This story is an excerpt from a longer interview that was collected as part of the Launching through the Surf: The Dory Fleet of Pacific City project. In this story, Don Grotjohn recounts an accident that occurred during a Dory Derby competition

Characterizing temporary hydrological regimes at a European scale

Monthly duration curves have been constructed from climate data across Europe to help address the relative frequency of ecologically critical low flow stages in temporary rivers, when flow persists only in disconnected pools in the river bed. The hydrological model is 5 based on a partitioning of precipitation to estimate water available for evapotranspiration and plant growth and for residual runoff. The duration curve for monthly flows has then been analysed to give an estimate of bankfull flow based on recurrence interval. The corresponding frequency for pools is then based on the ratio of bank full discharge to pool flow, arguing from observed ratios of cross-sectional areas at flood 10 and low flows to estimate pool flow as 0.1% of bankfull flow, and so estimate the frequency of the pool conditions that constrain survival of river-dwelling arthropods and fish. The methodology has been applied across Europe at 15 km resolution, and can equally be applied under future climatic scenarios

Reduction in Overall Occurrences of Ischemic Events with Vorapaxar: Results from TRACER

BACKGROUND: Clinical trials traditionally use time-to-first-event analysis embedded within the composite endpoint of cardiovascular death (CVD), myocardial infarction (MI), or stroke. However, many patients have \u3e1 event, and this approach may not reflect overall experience. We addressed this by analyzing all cardiovascular events in TRACER. METHODS AND RESULTS: TRACER randomized 12 944 patients with non-ST-segment elevation acute coronary syndromes to placebo or to protease-activated receptor 1 antagonist vorapaxar with a median follow-up of 502 days (interquartile range, 349 to 667). Analysis of vorapaxar\u27s effect on recurrent CVD, MI, or stroke was prespecified using the Wei, Lin, and Weissfeld approach. Vorapaxar did not reduce the first occurrence of the primary endpoint of CVD, MI, stroke, revascularization, or rehospitalization for recurrent ischemia, but reduced the secondary composite endpoint of CVD, MI, or stroke (14.7% vorapaxar vs. 16.4% placebo; hazard ratio [HR], 0.89; 95% confidence interval [CI], 0.81 to 0.98; P=0.02; number needed to treat [NNT], 81). Recurrent secondary events occurred in 2.7% of patients. Vorapaxar reduced overall occurrences of ischemic events, first and subsequent (HR, 0.88; 95% CI, 0.80 to 0.98; P=0.02; NNT, 51). Also, there was a trend indicating that vorapaxar reduced the expanded endpoint, including revascularization and rehospitalization for recurrent ischemia (HR, 0.92; 95% CI, 0.84 to 1.01; P=0.09). Vorapaxar increased overall occurrences of moderate and severe Global Use of Strategies to Open Occluded Coronary Arteries bleeding (HR, 1.42; 95% CI, 1.21 to 1.66; PP\u3c0.001). CONCLUSIONS: Vorapaxar reduced overall occurrences of ischemic events, but increased bleeding. These exploratory findings broaden our understanding of vorapaxar\u27s potential and expand our understanding of the value of capturing recurrent events

The role of genes, intelligence, personality, and social engagement in cognitive performance in Klinefelter syndrome

INTRODUCTION: The determinants of cognitive deficits among individuals with Klinefelter syndrome (KS) are not well understood. This study was conducted to assess the impact of general intelligence, personality, and social engagement on cognitive performance among patients with KS and a group of controls matched for age and years of education. METHODS: Sixty‐nine patients with KS and 69 controls were assessed in terms of IQ, NEO personality inventory, the Autism Spectrum Quotient (AQ) scale, and measures of cognitive performance reflecting working memory and executive function. RESULTS: Patients with KS performed more poorly on memory and executive‐function tasks. Patients with KS also exhibited greater neuroticism and less extraversion, openness, and conscientiousness than controls. Memory deficits among patients with KS were associated with lower intelligence, while diminished executive functioning was mediated by both lower intelligence and less social engagement. CONCLUSION: Our results suggest that among patients with KS, memory deficits are principally a function of lower general intelligence, while executive‐function deficits are associated with both lower intelligence and poorer social skills. This suggests a potential influence of social engagement on executive cognitive functioning (and/or vice‐versa) among individuals with KS, and perhaps those with other genetic disorders. Future longitudinal research would be important to further clarify this and other issues discussed in this research

Repeated Measurements of Cardiac Biomarkers in Atrial Fibrillation and Validation of the ABC Stroke Score Over Time

Background--Cardiac biomarkers are independent risk markers in atrial fibrillation, and the novel biomarker-based ABC stroke score (age, biomarkers, and clinical history of prior stroke) was recently shown to improve the prediction of stroke risk in patients with atrial fibrillation. Our aim was to investigate the short-term variability of the cardiac biomarkers and evaluate whether the ABC stroke risk score provides a stable short- term risk estimate. Methods and Results--According to the study protocol, samples were obtained at entry and also at 2 months in 4796 patients with atrial fibrillation followed for a median of 1.8 years in the ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation) trial. Cardiac troponin I, cardiac troponin T, and N-terminal pro-B-type natriuretic peptide were measured with high-sensitivity immunoassays. Associations with outcomes were evaluated by Cox regression. C indices and calibration plots were used to evaluate the ABC stroke score at 2 months. The average changes in biomarker levels during 2 months were small ( median change cardiac troponin T +2.8%, troponin I +2.0%, and N-terminal pro-B-type natriuretic peptide +13.5%) and within-subject correlation was high ( all >= 0.82). Repeated measurement of cardiac biomarkers provided some incremental prognostic value for mortality but not for stroke when combined with clinical risk factors and baseline levels of the biomarkers. Based on 8702 person-years of follow-up and 96 stroke/systemic embolic events, the ABC stroke score at 2 months achieved a similar C index of 0.70 (95% CI, 0.65-0.76) as compared with 0.70 (95% CI, 0.65-0.75) at baseline. The ABC stroke score remained well calibrated using predefined risk classes. Conclusions--In patients with stable atrial fibrillation, the variability of the cardiac biomarkers and the biomarker- based ABC stroke score during 2 months are small. The prognostic information by the ABC stroke score remains consistent and well calibrated with similar good predictive performance if patients are retested after 2 months. Clinical Trial Registration --URL: http://www.clinicaltrials.gov. Unique identifier: NCT00412984.Peer reviewe