While the clinical hallmarks of transient global amnesia (TGA) are well defined, its pathophysiological causes are poorly understood. Specifically, risk factors for recurrences are yet to be ...determined.
This retrospective study analyzed TGA cases diagnosed and treated within the TEMPiS telestroke network and a university stroke center in Germany. Demographic and clinical data were assessed and characteristics of TGA episodes were recorded, such as season of occurrence, trigger factors, duration, and concomitant symptoms. Follow-up of the potential recurrence of TGA was performed using a standardized questionnaire.
Overall 109 patients were included (age 64±8 years mean±SD, 59.6% female). The most common vascular risk factor was arterial hypertension (60.6%), and other concomitant conditions included migraine (11.9%), hypothyroidism (22.9%), and atrial fibrillation (4.6%). The most frequent concomitant clinical feature accompanying the TGA episode at admission was elevated blood pressure (48.6%). Nineteen patients experienced at least one recurrent TGA episode. Migraine and hypothyroidism were only observed in subjects with a single TGA episode without recurrence (migraine: 14.4% without recurrence vs. none in the recurrence group,
=0.02; hypothyroidism: 27.8% without recurrence vs. none in the recurrence group,
=0.009). In contrast, atrial fibrillation was more common in subjects with TGA recurrence (
<0.001).
Arterial hypertension is prevalent in TGA patients, with elevated blood pressure being the most-frequent concomitant condition. In our cohort, recurrence of TGA occurred in approximately one-fifth of patients. Concomitant conditions such as migraine, hypothyroidism, and atrial fibrillation occurred at different frequencies in the two groups.
Abstract
The macrocyclic calix4arene ligand H
2
L comprises two non‐fluorescent 2,6‐bis‐(iminomethyl)phenolate chromophores, which show a chelation‐enhanced fluorescence enhancement upon Zn
2+
ion ...complexation. Macrocyclic ZnL complexes aggregate in the absence of external coligands via intermolecular Zn−N bonds to give dimeric ZnL
2
structures comprising two five‐coordinated Zn
2+
ions. The absorption and emission wavelengths are bathochromically shifted upon going from the liquid (λ
max,abs
(CH
2
Cl
2
)=404 nm, λ
max,em
(CH
2
Cl
2
)=484 nm) to the solid state (λ
max,abs
=424 nm (4 wt%, BaSO
4
pellet), λ
max,em
=524 nm (neat solid)). Insights into the electronic nature of the UV‐vis transitions were obtained with time‐dependent density functional theory (TD‐DFT) calculations for a truncated model complex.
The macrocyclic calix4arene ligand H2L comprises two non‐fluorescent 2,6‐bis‐(iminomethyl)phenolate chromophores, which show a chelation‐enhanced fluorescence enhancement upon Zn2+ ion complexation. ...Macrocyclic ZnL complexes aggregate in the absence of external coligands via intermolecular Zn−N bonds to give dimeric ZnL2 structures comprising two five‐coordinated Zn2+ ions. The absorption and emission wavelengths are bathochromically shifted upon going from the liquid (λmax,abs (CH2Cl2)=404 nm, λmax,em (CH2Cl2)=484 nm) to the solid state (λmax,abs=424 nm (4 wt%, BaSO4 pellet), λmax,em=524 nm (neat solid)). Insights into the electronic nature of the UV‐vis transitions were obtained with time‐dependent density functional theory (TD‐DFT) calculations for a truncated model complex.
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•A new hybrid picolyl-imine calix4arene ligand H3L2 has been synthesized.•The coordination behavior towards selected f-elements (Nd, Eu, Tb, Yb) has been elucidated.•The antennae ...effect of the appended picolyl-imines has been detected.•The new compounds provide a basis for the further development of Ln-based luminescent materials and sensors.
The complexation behavior of a calix4arene ligand H3L2 bearing a pendant picolyl-imine arm towards some lanthanide ions has been investigated. Reaction of H3L2 with the LnIII ions Nd (4), Eu (5), Tb (6) and Yb (7) in the presence of NEt3 provides dimeric neutral complexes of composition {Ln(L2)(MeCN)}2 comprising doubly-bridged N2O3Ln(μ-O)2LnO3N2 cores with seven-coordinated lanthanide ions. UV–vis spectrophotometric titrations show that dimeric species are also present in CH2Cl2/MeOH (3/1 v/v) and MeCN solution, respectively. The apparent stability constants being log K = 5.81(2) for 4, log K = 6.05(5) for 5, log K = 5.72(1) for 6 and log K 5.74(1) for 7. The appended picolyl-imines sensitize EuIII and TbIII emission (λex 296 nm) in the solid state or immersed in a PMMA matrix at 298 K and 77 K.
The macrocyclic calix4arene ligand H2L comprises two non‐fluorescent 2,6‐bis‐(iminomethyl)phenolate chromophores, which show a chelation‐enhanced fluorescence enhancement upon Zn2+ ion complexation. ...Macrocyclic ZnL complexes aggregate in the absence of external coligands via intermolecular Zn−N bonds to give dimeric ZnL2 structures comprising two five‐coordinated Zn2+ ions. The absorption and emission wavelengths are bathochromically shifted upon going from the liquid (λmax,abs (CH2Cl2)=404 nm, λmax,em (CH2Cl2)=484 nm) to the solid state (λmax,abs=424 nm (4 wt%, BaSO4 pellet), λmax,em=524 nm (neat solid)). Insights into the electronic nature of the UV‐vis transitions were obtained with time‐dependent density functional theory (TD‐DFT) calculations for a truncated model complex.
Zn2+ complexes of hybrid bis(iminomethyl)phenol/calix4arene macrocycles dimerize in the absence of external coligands to afford bright green fluorescent complexes (λem=524 nm) The fluorescence enhancement is attributed to the inhibition of photo‐induced electron transfer processes in the Zn2+‐bound bis(iminomethyl)phenolate chromophores.
The synthesis, structures, and properties of a new calix4arene ligand with an appended salicylaldimine unit (H4L = 25-2-((2-methylphenol)imino)ethoxy-26,27,28-trihydroxy-calix4arene) and four ...lanthanide complexes (HNEt3)Ln2(HL)(L) (Ln = SmIII (4), EuIII (5), GdIII (6), and TbIII (7)) are reported. X-ray crystallographic analysis (for 4 and 6) reveals an isostructural series of dimeric complexes with a triply-bridged NO3Ln(μ-O)2(OHO)LnO3N core and two seven coordinated lanthanide ions. According to UV-vis spectrometric titrations in MeCN and ESI-MS the dimeric nature is maintained in solution. The apparent stability constants range between log K = 5.8 and 6.3. The appended salicylaldimines sensitize EuIII and TbIII emission (λexc 311 nm) in the solid state or immersed in a polycarbonate glass at 77 K (for 5, 7) and at 295 K (for 7).
The ability of macrocyclic Co and Ni aminothiolate complexes to act as metalloligands towards cuprate ions was established. Adduct formation is enabled by a thiolate-to-Cu
+
charge transfer (CT) ...interaction giving stable heterotrimetallics with magnetic properties.
The bridging thiolate sulfur atoms in macrocyclic Ni and Co complexes exhibit metalloligand behaviour, forming adducts with various cuprate ions.
For many years clinical research has been concerned with doppler sonography as a non-invasive tool for intrauterine fetal status assessment. A new focus is now placed on the measurement of ...cerebroplacental index (CPR) as a predictor of fetal outcome. Our aim was to investigate the relationship between the cerebroplacental ratio (CPR), the delivery mode and the fetal outcome in singleton pregnancies.
A retrospective cohort study of pregnancies in which doppler sonography of middle cerebral artery (MCA) and umbilical artery (UA) was conducted up to 9 weeks before delivery took place. Patients with pathological (CPR≤1.0) and normal CPR (>1.0) were compared by umbilical cord pH, APGAR scores, birth weight, delivery week and delivery mode.
A total of 2,270 singleton pregnancies were included. The APGAR score for 1, 5 and 10 minutes and the gestational age at delivery were significantly lower in the group of patients with pathological CPR (p<0.001). Overall, 50% of the cohort had a cesarean section, the difference between the groups was statistically significant (p<0.001), with a higher amount of cesareans in the group of patients with pathological CPR. The multiple regression analysis showed a significantly improved pH of delivery when cesarean section (p<0.001), female sex of fetus (p=0.013) and higher CPR (p=0.035) were present.
The measurement of CPR is an important, non-invasive predictive parameter and leads to the identification of a risk collective even in the non-selected patient population and thus probably to a reduction of perinatal morbidity.
The synthesis and photophysical properties of four new hybrid salicylaldiminato-calix4arene ligands and their corresponding zinc(ii) complexes are described. The Schiff bases were obtained from ...condensation reactions between cone-25,27-di(aminoethoxy)-26,28-dihydroxy-calix4arene and salicylaldehyde (H2L1) or o-vanillin (H2L2) and 1,3-alt-25,27-di(aminoethoxy)-26,28-di(n-propyloxy)-calix4arene and 3,5-di-tert-butyl-salicylaldehyde (H2L3) or o-vanillin (H2L4). Complexation reactions were investigated by ESI-MS, IR, NMR, UV-vis absorption and steady-state and time resolved fluorescence spectroscopy, and X-ray crystallography. All ligands support 1 : 1 complexes (ZnL1-ZnL4), with equilibrium constants derived from absorption spectrophotometry in the range log K11 = 5.5-8.2 (MeCN or MeOH/CH2Cl2, I = 0.01 M). The zinc complexes show blue fluorescence, both in solution as well as in the solid state, with λem, Φf, and τ ranging from 472-504 nm, 0.11-0.60, and 2-9 ns, respectively. The nature of the substituents on the salicylaldiminato fragments was found to be the main parameter that influences the photophysical properties of the zinc complexes. Insights into the electronic nature of the UV-vis transitions were obtained with time dependent density functional theory (TD-DFT) calculations.
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