The concurrent formation of furan-2,5- and furan-2,4-dicarboxylic acid under solvent free conditions via a disproportionation reaction is described. By reacting potassium-2-furoate at 260 degrees C ...in the presence of 22 mol% of (Lewis acidic) catalysts like CdI2 or ZnCl2, potassium-2-furoate is disproportionated to furan and furandicarboxylic acids. Besides furan and furan-2,5-dicarboxylic acid (2,5-FDCA) as the main products, furan-2,4-dicarboxylic acid (2,4-FDCA) is also formed as a by-product. Experimental evidence has been obtained that, under the reaction conditions applied, 2,5-FDCA and 2,4-FDCA are formed by separate reaction pathways. Selectivity towards the different FDCA isomers is affected by the type of catalyst used. Single-crystal X-ray analysis shows that 2,4-FDCA has a more 'linear' character compared to 2,5-FDCA and hence is structurally more comparable to terephthalic acid (TA), making it an interesting monomer for synthetic polyesters.
An efficient palladium catalyst is presented for the formation of benzylic quaternary stereocenters by conjugate addition of arylboronic acids to a variety of β,β‐disubstituted carbocyclic, ...heterocyclic, and acyclic enones. The catalyst is readily prepared from PdCl2, PhBOX, and AgSbF6, and provides products in up to 99 % enantiomeric excess, with good yields. Based on this strategy, (−)‐α‐cuparenone has been prepared in only two steps.
Jack of all trades: An efficient Pd catalyst for the formation of benzylic quaternary stereocenters by conjugate addition of arylboronic acids to a variety of β,β‐disubstituted cyclic and acyclic enones is presented (see scheme). The catalyst provides product enantioselectivities up to 99 %.
Considerable effort is being devoted to the fabrication of nanoscale devices. Molecular machines, motors and switches have been made, generally
operating in solution, but for most device applications
...(such as electronics and opto-electronics), a maximal degree of order and
regularity is required. Crystalline materials would be excellent
systems for these purposes, as crystals comprise a vast number of self-assembled
molecules, with a perfectly ordered three-dimensional structure.
In non-porous crystals, however, the molecules are densely packed and any
change in them (due, for example, to a reaction) is likely to destroy the
crystal and its properties. Here we report the controlled and fully reversible
crystalline-state reaction of gaseous SO2 with non-porous crystalline
materials consisting of organoplatinum molecules. This process, including
repetitive expansion-reduction sequences (on gas uptake and release)
of the crystal lattice, modifies the structures of these molecules without
affecting their crystallinity. The process is based on the incorporation of
SO2 into the colourless crystals and its subsequent liberation
from the orange adducts by reversible bond formation and cleavage.
We therefore expect that these crystalline materials will find applications
for gas storage devices and as opto-electronic switches.
A bulky cyclopentadienyl (Cp)‐based trioxorhenium compound was developed for the catalytic deoxydehydration of vicinal diols to olefins. The 1,2,4‐tri(tert‐butyl)cyclopentadienyl trioxorhenium (2) ...catalyst was synthesised in a two‐step synthesis procedure. Dirhenium decacarbonyl was converted into 1,2,4‐tri(tert‐butyl)cyclopentadienyl tricarbonyl rhenium, followed by a biphasic oxidation with H2O2. These two new three‐legged compounds with a ‘piano‐stool’ configuration were fully characterised, including their single crystal X‐ray structures. Deoxydehydration reaction conditions were optimised by using 2 mol % loading of 2 for the conversion of 1,2‐octanediol into 1‐octene. Different phosphine‐based and other, more conventional, reductants were tested in combination with 2. Under optimised conditions, a variety of vicinal diols (aromatic and aliphatic, internal and terminal) were converted into olefins in good to excellent yields, and with minimal olefin isomerisation. A high turnover number of 1400 per Re was achieved for the deoxydehydration of 1,2‐octanediol. Furthermore, the biomass‐derived polyols (glycerol and erythritol) were converted into their corresponding olefinic products by 2 as the catalyst.
In the bulk of it: Bulky 1,2,4‐tri(tert‐butyl)cyclopentadienyl trioxorhenium was studied as a catalyst for the deoxydehydration of different vicinal diols. Under optimised conditions, a variety of vicinal diols were converted into olefins in good to excellent yields, and with minimal olefin isomerisation. Biomass‐derived polyols were also converted into their corresponding olefinic products.
Recently, Brønsted acids, such as phosphoric acids, carboxylic acids, and triflic acid, were found to catalyze the reduction of phosphine oxides to the corresponding phosphines. In this study, we ...fully characterize the HCl, HOTf, and Me2SiHOTf adducts of triphenylphosphine oxide and find that the thermally stable adduct Ph3POH+OTf– is efficiently converted into triphenylphosphine at 100 °C in the presence of readily available hydrosiloxanes. Under the same reaction conditions, also Ph3POSiMe2H+OTf– selectively affords triphenylphosphine indicating that silylated phosphine oxides are likely intermediates in this process.
Background: As of 2017, South Carolina ranked 5th highest in the U.S. for percentage of adults with diabetes, which has negative health and cost implications. The innovative community paramedicine ...program (CPP) aims to improve management of patients with chronic diseases and high utilization of the Emergency Department (ED), by providing in-home disease management, education, and care/community resource connection by paramedics. The impact of CPs has not been extensively studied in diabetes.
Objective: To assess impact of CPP participation on health outcomes and healthcare utilization for patients with diabetes.
Methods: Retrospective analysis of CPP participants diagnosed pre-enrollment with diabetes. Demographics and variables reported as percentages, and differences between A1c values pre/post CPP tested using Student’s t-test. Healthcare cost and utilization data was extracted from EMR using SAP BusinessObjects and analyzed with Qlik.
Results: From 2015-2019, 64 people with diabetes enrolled. Participants were primarily insured by Medicare (48.4%) and/or Medicaid (35.9%) or uninsured (32.8%). Comparing pre and post-enrollment average values, participants in CPP for >180 days (d) demonstrated a clinically significant improvement in A1c, although this did not reach statistical significance (181-270d: 10.04+/-1.33 to 8.51+/-1.35, p=0.159; 271-365d: 10.83+/-2.95 to 7.65+/-2.39,p=0.098; 365+d: 9.31+/-2.58 to 7.76 +/-1.45, p=0.23). Participants also showed increased rates of screening for microvascular complications. To date, the utilization analysis for the 52 CPP graduates who participated >14d suggests decrease in average cost of care and ED visits per person comparing 6 months prior and up to 6 months post CPP enrollment ($16,514 vs. $4,717; 2.77 vs. 0.73 ED visits).
Conclusions: The CPP demonstrated improvement in disease control and reduced costs/ED visits for patients with diabetes. This is a promising care delivery innovation that merits further research.
Disclosure
M. Eicken: None. D. Lee: None. J.A. Ewing: None. J.N. Butler: None. M.E. Lutz: None. J.Z. Snow: None. C. Hipp: None. D.T. Thomas: None. C.P. Head: None. R.S. Hudson-Dobbs: None. V.E. Green: None. S.L. Weber: None.
Abstract
BACKGROUND:
Tractography based on diffusion tensor imaging has become a popular tool for delineating white matter tracts for neurosurgical procedures.
OBJECTIVE:
To explore whether navigated ...transcranial magnetic stimulation (nTMS) might increase the accuracy of fiber tracking.
METHODS:
Tractography was performed according to both anatomic delineation of the motor cortex (n = 14) and nTMS results (n = 9). After implantation of the definitive electrode, stimulation via the electrode was performed, defining a stimulation threshold for eliciting motor evoked potentials recorded during deep brain stimulation surgery. Others have shown that of arm and leg muscles. This threshold was correlated with the shortest distance between the active electrode contact and both fiber tracks. Results were evaluated by correlation to motor evoked potential monitoring during deep brain stimulation, a surgical procedure causing hardly any brain shift.
RESULTS:
Distances to fiber tracks clearly correlated with motor evoked potential thresholds. Tracks based on nTMS had a higher predictive value than tracks based on anatomic motor cortex definition (P < .001 and P = .005, respectively). However, target site, hemisphere, and active electrode contact did not influence this correlation.
CONCLUSION:
The implementation of tractography based on nTMS increases the accuracy of fiber tracking. Moreover, this combination of methods has the potential to become a supplemental tool for guiding electrode implantation.
•Seizure frequency was significantly correlated with depression and anxiety symptoms.•Initial level of depression predicted seizure frequency after inpatient treatment.•The impact of comorbid ...psychiatric problems on seizure frequency is emphasized.
Depressive and anxiety disorders are frequent among people with epilepsies. There are, however, only few longitudinal studies, which examine the relationship between these comorbid psychiatric disorders and epilepsy-related variables. Thus, we investigated the interrelationships of depression and anxiety symptoms with seizure frequency across time.
Before admittance to an epilepsy center (T1) and six months after discharge (T2), patients (n=198) with mainly difficult-to-treat epilepsies completed the Hospital Anxiety and Depression Scale (HADS). Correlation and path analyses were conducted.
Depression and anxiety symptoms (HADS) as well as seizure frequency significantly decreased from baseline to follow-up. Both at T1 and T2, seizure frequency was slightly, but significantly correlated with depression and anxiety levels (rs =0.17–.32). Cross-lagged-analyses showed that baseline (T1) level of depression significantly predicted frequency of seizures at follow-up (T2). However, anxiety at T1 was not a significant predictor of seizure frequency at T2 and seizure frequency at T1 did not predict either depressive or anxiety symptoms at T2.
The present findings emphasize the importance of psychiatric comorbidities, especially depression, for seizure frequency and its progress in patients with difficult-to-treat epilepsies referred to a specialized epilepsy center. Thus, comorbid psychiatric disorders need specific consideration as part of a comprehensive diagnostic and therapeutic treatment approach.
A large library of Cu(II) complexes with mononucleating and dinucleating ligands was synthesized to investigate their potential as catalysts for the catalytic oxidation of 3,5-di-tert-butylcatechol ...(3,5-DTBC). X-ray structure determination for a number of these complexes revealed relatively large Cu···Cu distances and the formation of polymeric species. Comparison of the 3,5-DTBC oxidation rates showed that ligands that stabilize the biomimetic dinuclear Cu(II) μ-thiolate complex also result in copper compounds that are much more active in the oxidation of 3,5-DTBC. This oxidation activity is however inhibited by the presence of chloride ions. The highest kcat that was observed was 6900 h(-1), which is one of the highest turnover frequencies reported so far for catechol oxidation in CH3CN.
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