4,5-Bis(2,4-di-tert-butyl­phen­oxy)phthalonitrile

In the title compound, C36H44N2O2, the dihedral angles between the phthalonitrile ring and the two di-tert-butyl­benzene rings are 68.134 (8) and 70.637 (11)°. The two nitrile groups are almost coplanar with the phthalonitrile ring except for one of the N atoms which deviates from the plane by 0.125 (4) Å. One of the tert-butyl groups is disordered over two orientations, with refined occupancies of 0.814 (6) and 0.186 (6). Intra­molecular C—H⋯O inter­actions stabilize the molecular structure. The crystal packing is stabilized by inter­molecular C—H⋯N inter­actions

Precise Neutron Magnetic Form Factors

Precise data on the neutron magnetic form factor G_{mn} have been obtained with measurements of the ratio of cross sections of D(e,e'n) and D(e,e'p) up to momentum transfers of Q^2 = 0.9 (GeV/c)^2. Data with typical uncertainties of 1.5% are presented. These data allow for the first time to extract a precise value of the magnetic radius of the neutron.Comment: 10 pages, 2 figures, submitted to Physics Letters

Vector and Tensor Analyzing Powers of the H(d,gamma)He-3 capture reaction

Precise measurements of the deuteron vector analyzing power Ayd and the tensor analyzing power Ayy of the H(d,gamma)He-3 capture reaction have been performed at deuteron energies of 29MeV and 45MeV. The data have been compared to theoretical state-of-the-art calculations available today. Due to the large sensitivity of polarization observables and the precision of the data light could be shed on small effects present in the dynamics of the reaction.Comment: 11 pages, 24 figures, submitted for publication to PRC, revised after referee proces

A Measurement of the Electric Form Factor of the Neutron through d⃗(e⃗,e′n)p\vec{d}(\vec{e},e'n)p at Q2=0.5Q^2 = 0.5 (GeV/c)2^2

We report the first measurement of the neutron electric form factor $G_E^n$ via $\vec{d}(\vec{e},e'n)p$ using a solid polarized target. $G_E^n$ was determined from the beam-target asymmetry in the scattering of longitudinally polarized electrons from polarized deuterated ammonia, $^{15}$ND$_3$. The measurement was performed in Hall C at Thomas Jefferson National Accelerator Facility (TJNAF) in quasi free kinematics with the target polarization perpendicular to the momentum transfer. The electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle segmented detector. We find $G_E^n = 0.04632\pm0.00616 (stat.) \pm0.00341 (syst.)$ at $Q^2 = 0.495$ (GeV/c)$^2$.Comment: Latex2e 5 pages, 3 figure

Measurement of the asymmetries in 3He→ \overrightarrow{\sf He}(¯e, e′p)d and 3He→ \overrightarrow{\sf He}(¯e, e′p)np

Abstract.: The electron target asymmetries A || and A⊥ with target spin parallel and perpendicular to the momentum transfer \ensuremath{\boldsymbol{q}} were measured for both the two- and three-body breakup of 3He in the 3 $\overrightarrow{\rm He}$ (¯e, e'p)-reaction. Polarized electrons were scattered off polarized 3He in the quasielastic regime in parallel kinematics with the scattered electron and the knocked-out proton detected using the Three-Spectrometer Facility at MAMI. The results are compared to Faddeev calculations which take into account Final-State Interactions as well as Meson Exchange Currents. The experiment confirms the prediction of a large effect of Final-State Interactions in the asymmetry of the three-body breakup and of an almost negligible one for the two-body breaku

Can Echocardiographic Findings Predict Falls in Older Persons?

Background. The European and American guidelines state the need for echocardiography in patients with syncope. 50% of older adults with syncope present with a fall. Nonetheless, up to now no data have been published addressing echocardiographic abnormalities in older fallers. Method and Findings. In order to determine the association between echocardiographic abnormalities and falls in older adults, we performed a prospective cohort study, in which 215 new consecutive referrals (age 77.4 SD 6.0) of a geriatric outpatient clinic of a Dutch university hospital were included. During the previous year, 139 had experienced a fall. At baseline, all patients underwent routine two-dimensional and Doppler echocardiography. Falls were recorded during a three-month follow-up. Multivariate adjustment for compounders was performed with a Cox proportional hazards model. 557 patients (26%) fell at least once during follow-up. The adjusted hazard ratio of a fall during follow-up was 135 (95% Cl, 1.08-1.71) for pulmonary hypertension, 1.66 (95% Cl, 1.01 to 2.89) for 4-initial regurgitation, 2.41 (95% Cl, 1.32 to 4.37) for tricuspid regurgitation and 1.76 (95% Cl, 1.03 to 3.01) for pulmonary regurgitation. For aoitic regurgitation the risk of a fall was also increased, but non-significantly. (hazard ratio, 1.57 [95% Cl 0.85 to 2.92]). Trend analysis of the severity of the difterent regurgitations showed a significant relationship for mitral, tricuspid and pulmonary valve regurgitation and pulmonary hypertension. Conclusions. Echo(Dopler)cardiography can be useful in order to identify risk indicators for falling. Presence of pulmonary hypertension or regurgitation of mitral, tricuspid or pulmonary valves was associated with a higher fall risk. Our study indicates that the diagnostic work-up for falls in older adults might be improved by adding an echo(Doppler)cardiogram in selected groups

Use of a Repositionable and Fully Retrievable Aortic Valve in Routine Clinical Practice: The RESPOND Study and RESPOND Extension Cohort

Objectives: The authors sought to evaluate 1-year clinical outcomes with the Lotus valve (Boston Scientific, Marlborough, Massachusetts) in a large international, multicenter prospective registry including patients eligible for transcatheter aortic valve replacement (TAVR) based on heart team consensus. Background: TAVR is a safe and effective treatment for severe aortic valve stenosis; however, limited data are available on TAVR with the repositionable and fully retrievable Lotus valve in unrestricted contemporary clinical practice. Methods: The RESPOND (Repositionable Lotus Valve System—Post-Market Evaluation of Real World Clinical Outcomes) study enrolled 1,014 patients; 996 patients were implanted with the Lotus valve (mean age 80.8 years, 50.8% female, mean STS score 6.0 ± 6.9%). The primary endpoint was all-cause mortality in the intent-to-treat population at 30 days and 1 year. An Extension cohort of 50 patients was treated with the Lotus valve with Depth Guard including a modified delivery system. Mortality and stroke were independently adjudicated. An independent core laboratory assessed echocardiographic data. Results: One-year clinical follow-up was available for 99.9% of Lotus valve-treated patients. At 1 year, the all-cause mortality rate was 11.7% and 4.1% of patients had experienced a disabling stroke. The permanent pacemaker implantation rate was 32% (37% among pacemaker-naive patients). Echocardiographic data at 1 year were available for core laboratory assessment in 62.6% of patients. Paravalvular leak was absent or trace in 94.5%, mild in 5.1%, and moderate in 0.4% of patients. Data from the Extension cohort confirmed good clinical outcomes at 30 days with an 18% permanent pacemaker rate (20% among pacemaker-naive patients). Conclusions: One-year outcomes from the RESPOND study confirm the safety and efficacy of the Lotus valve when used in routine clinical practice. (Repositionable Lotus Valve System—Post-Market Evaluation of Real World Clinical Outcomes [RESPOND]; NCT02031302

Tetrabenzoporphyrin and -mono-, - Cis -di- and tetrabenzotriazaporphyrin derivatives: Electrochemical and spectroscopic implications of meso CH Group replacement with nitrogen

Nonperipherally hexyl-substituted metal-free tetrabenzoporphyrin (2H-TBP, 1a) tetrabenzomonoazaporphyrin (2H-TBMAP, 2a), tetrabenzo-cis-diazaporphyrin (2H-TBDAP, 3a), tetrabenzotriazaporphyrin (2H-TBTAP, 4a), and phthalocyanine (2H-Pc, 5a), as well as their copper complexes (1b-5b), were synthesized. As the number of meso nitrogen atoms increases from zero to four, Îmax of the Q-band absorption peak becomes red-shifted by almost 100 nm, and extinction coefficients increased at least threefold. Simultaneously the blue-shifted Soret (UV) band substantially decreased in intensity. These changes were related to the relative electron-density of each macrocycle expressed as the group electronegativity sum of all meso N and CH atom groups, âχR. X-ray photoelectron spectroscopy differentiated between the three different types of macrocyclic nitrogen atoms (the Ninner, (NH)inner, and Nmeso) in the metal-free complexes. Binding energies of the Nmeso and Ninner,Cu atoms in copper chelates could not be resolved. Copper insertion lowered especially the cathodic redox potentials, while all four observed redox processes occurred at larger potentials as the number of meso nitrogens increased. Computational chemical methods using density functional theory confirmed 1b to exhibit a Cu(II) reduction prior to ring-based reductions, while for 2b, Cu(II) reduction is the first reductive step only if the nonperipheral substituents are hydrogen. When they are methyl groups, it is the second reduction process; when they are ethyl, propyl, or hexyl, it becomes the third reductive process. Spectro-electrochemical measurements showed redox processes were associated with a substantial change in intensity of at least two main absorbances (the Q and Soret bands) in the UV spectra of these compounds