Synthesis and physical properties of tunable aryl alkyl ionic liquids based on 1-aryl-4,5-dimethylimidazolium cations.

We present a new class of tunable aryl alkyl ionic liquids (TAAILs) based on 1-aryl-4,5-dimethylimidazolium cations with electron-withdrawing and -donating substituents in different positions of the phenyl ring and the bis(trifluoromethylsulfonyl)imide (NTf2) anion. We investigated the effect of additional methyl groups in the backbone of the imidazolium core on the physical properties regarding viscosity, conductivity and electrochemical window. With an electrochemical window of up to 6.3 V, which is unprecedented for TAAILs with an NTf2 anion, this new class of TAAILs demonstrates the opportunities that arise from modifications in the backbone of the imidazolium cation.

Friedel-Crafts acylation of benzene derivatives in tunable aryl alkyl ionic liquids (TAAILs).

An iron(III) chloride hexahydrate-catalyzed Friedel-Crafts acylation of benzene derivatives in tunable aryl alkyl ionic liquids (TAAILs) has been developed. Through optimization of the metal salt, reaction conditions and ionic liquids, we were able to design a robust catalyst system that tolerates different electron-rich substrates under ambient atmosphere and allows for a multigram scale.

Total Synthesis of Resveratrone and iso-Resveratrone.

The first total synthesis of resveratrone and iso-resveratrone based on an epoxide olefination approach is described. The pivotal reaction proceeds by insertion of the lithiated epoxide into a boronic ester and subsequent syn-elimination. Resveratrone has been described to have remarkable photophysical properties, including two-photon absorption. Therefore, an azide derivative has been prepared to allow for use as a biological label.

Iterative Synthesis of Alkenes by Insertion of Lithiated Epoxides into Boronic Esters.

The insertion of lithiated epoxides into boronic esters followed by thermal syn-elimination provides a stereospecific entry to alkenes. This process avoids transition metals and is amenable to iteration to provide higher substitution patterns.

Which radiographic hip parameters do not have to be corrected for pelvic rotation and tilt?

BACKGROUND: Acetabular anatomy on AP pelvic radiographs depends on pelvic orientation during radiograph acquisition. However, not all parameters may change to a clinically relevant degree with differences in pelvic orientation. This issue may influence the diagnosis of acetabular pathologies and planning of corrective acetabular surgery (reorientation or rim trimming). However, to this point, it has not been well characterized. QUESTIONS/PURPOSES: We asked (1) which radiographic parameters change in a clinical setting when normalized to neutral pelvic orientation; (2) which parameters do not change in an experimental setting when the pelvis is experimentally rotated/tilted; and (3) which of these changes are "ultimately" relevant based on a prespecified definition of relevance. METHODS: In a clinical setup, 11 hip parameters were evaluated in 101 patients (126 hips) by two observers and the interobserver difference was calculated. All parameters were normalized to an anatomically defined neutral pelvic orientation with the help of a lateral pelvic radiograph and specific software. Differences between nonnormalized and normalized values were calculated (effect of normalization). In an experimental setup involving 20 cadaver pelves (40 hips), the maximum range for each parameter was computed with the pelvis rotated (range, -12° to 12°) and tilted (range, -24° to 24°). "Ultimately" relevant changes existed if the effect of normalization exceeded the interobserver difference (eg, 37% versus 6% for prevalence of a positive crossover sign) and/or the maximum experimental range exceeded 1 SD of interobserver difference (eg, 27% versus 6% for anterior acetabular coverage). RESULTS: In the clinical setup, all parameters except the ACM angle and craniocaudal acetabular coverage changed when being normalized, eg, effect of normalization for lateral center-edge angle, acetabular index, and sharp angle ranged from -5° to 4° (p values < 0.029). In the experimental setup, five parameters showed no major changes, whereas six parameters did change (all p values < 0.001). Ultimately relevant changes were found for anteroposterior acetabular coverage, retroversion index, and prevalence of a positive crossover or posterior wall sign. CONCLUSIONS: Lateral center-edge angle, ACM angle, Sharp angle, acetabular and extrusion index, and craniocaudal acetabular coverage showed no relevant changes with varying pelvic orientation and can therefore be acquired independent from individual pelvic tilt and rotation in clinical practice. In contrast, anteroposterior acetabular coverage, crossover and posterior wall sign, and retroversion index call for specific efforts that address individual pelvic orientation such as computer-assisted evaluation of radiographs.

Transvenous, intracardial cardioversion for the treatment of postoperative atrial fibrillation.

Atrial fibrillation (AF) following cardiac surgery is an important factor contributing to postoperative morbidity. Transvenous, intracardial cardioversion (TIC) has been shown to be effective in the treatment of chronic AF, but is an invasive and cost-intensive procedure. However, TIC would definitely be a beneficial approach if recurrence of AF following TIC is low and pharmacological treatment could be avoided. Thus, we hypothesised that TIC would be superior to conventional treatment with amiodarone with respect to the conversion rate and recurrence of AF. We compared TIC and conventional amiodarone therapy in a prospective, randomised and controlled trial in patients who developed AF following cardiac surgery. Twenty-three patients developed AF out of a total of 76 patients who gave written informed consent. Eighteen of these AF patients could be randomised into two equally sized groups to receive either an ALERT pulmonary artery catheter and TIC, or a standard pulmonary artery catheter and treatment with amiodarone. Haemodynamic parameters were registered before intervention to exclude pulmonary hypertension or fluid overload. Rates of cardioversion were compared by a Likelyhood ratio test. Out of the nine ALERT patients, AF in five cases converted to sinus rhythm (SR) with a median of two shocks (6 J). After 24 hours however, only two patients remained in sinus rhythm. On the other hand, six of the nine patients treated with amiodarone were still in SR after 24 hours. Whereas no difference was detectable in the conversion rate, persistence of SR following TIC was low. Thus, TIC without antiarrhythmic treatment is not recommendable for the treatment of postoperative AF.