Diffusion in a series of ionic liquids is investigated by a combination of Broadband Dielectric Spectroscopy (BDS) and Pulsed Field Gradient Nuclear Magnetic Resonance (PFG NMR). It is demonstrated ...that the mean jump lengths increase with the molecular volumes determined from quantum-chemical calculations. This provides a direct means-via Einstein-Smoluchowski relation-to determine the diffusion coefficient by BDS over more than 8 decades unambiguously and in quantitative agreement with PFG NMR measurements. New possibilities in the study of charge transport and dynamic glass transition in ionic liquids are thus opened.
Charge transport and glassy dynamics of a variety of glass-forming ionic liquids (ILs) are investigated in a wide frequency and temperature range by means of broadband dielectric spectroscopy, ...differential scanning calorimetry and rheology. While the absolute values of dc conductivity and viscosity vary over more than 11 decades with temperature and upon systematic structural variation of the ILs, quantitative agreement is found between the characteristic frequency of charge transport and the structural alpha-relaxation. This is traced back to dynamic glass transition assisted hopping as the underlying mechanism of charge transport.
Charge transport in ionic liquids contained in unidirectional nanoporous membranes (pore diameters: 7.510.4 nm) is investigated by combining broadband dielectric spectroscopy (BDS) and pulsed field ...gradient (PFG)-NMR. This enables one to determine the diffusion coefficient and the diffusion rate over more than 13 decades and to trace its temperature dependence. Under conditions of nanometric confinement, a change from a VogelFulcherTammann into an Arrhenius-like thermal activation is observed, resulting in an enhancement of diffusivities by more than two orders of magnitude. The effect becomes more pronounced with decreasing pore diameter. It is attributed to changes in molecular packing and hence in density leading to higher mobility and electrical conductivity.
Diffusion coefficients of ionic liquids increase by over two orders of magnitude under nanometric confinement.
Five binuclear complexes with rectangular topology have been synthesized using a nitronyl‐nitroxide ligand (L) functionalized with a pyrazole coordinating group: Ln2(hfac)2L2, with Ln=Eu (1), Gd (2 ...a, 2 b), Tb (3), Dy (4), Tm (5). The EuIII and TmIII complexes crystallize in the P21/n space group, while the GdIII, TbIII, and DyIII derivatives crystalize in P‐1 space group. The crystal structures for compounds 2 a, 3, 4, and 5 have been fully solved, while for compounds 1 and 2 b, the unit cell parameters have been measured and compared with crystals 3 and 5. Crystals 2 a (P21/n) and 2 b (P‐1) are polymorphic forms. In these complexes the nitronyl‐nitroxide ligand bridges two metal ions through one aminoxyl group and the pyrazole fragment. In the five complexes the LnIII ions show a coordination number of eight with a triangular dodecahedron geometry. The magnetic properties of all five complexes have been investigated. For compounds 2, 3, and 4 the LnIII‐Rad interaction was found to be ferromagnetic: JGdRad=2.09(1) cm−1 H=‐2JGdRad(SGd1SRad1+SGd2SRad2, JTbRad=1.93(14) cm−1, JDyRad=1.72(14) cm−1. The TmIII‐Rad coupling is antiferromagnetic (JTmRad=−0.53(1) cm−1). For the TbIII, DyIII, and TmIII complexes the effects of the crystal field have been taken into account in the fitting procedure.
A series of five binuclear 2p‐4f complexes has been obtained using as a bridging ligand a new nitronyl‐nitroxide radical functionalized with a N‐donor group. The magnetic properties of these rectangular‐shaped complexes have been investigated.
Middle molecular weight uraemic toxins are considered to play an important role in vascular dysfunction and cardiovascular outcomes in end-stage renal disease (ESRD) patients. Recent dialysis ...techniques based on convection, specifically high-efficiency on-line haemodiafiltration (HDF), enhance the removal of middle molecular weight toxins and reduce all-cause mortality in haemodialysis (HD) patients. However, the mechanisms of these improved outcomes remain to be established.
This prospective study randomly assigned 42 ESRD patients to switch from high-flux HD to high-efficiency on-line HDF (n=22) or to continue HD (n=20). Brachial artery endothelium-dependent flow-mediated dilatation, central pulse pressure, carotid artery intima-media thickness (IMT), internal diastolic diameter and distensibility and circulating markers of uraemia, inflammation and oxidative stress were blindly assessed before and after a 4-month follow-up.
Brachial flow-mediated dilatation and carotid artery distensibility increased significantly in the HDF group compared with HD, while carotid IMT and diameter remained similar. HDF decreased predialysis levels of the uraemic toxins β2-microglobulin, phosphate and blood TNFα mRNA expression. Oxidative stress markers were not different between the HD and HDF groups. Blood mRNA expression of protein kinase C β2, an endothelial NO-synthase (eNOS) inhibitor, decreased significantly with HDF.
High-efficiency on-line HDF prevents the endothelial dysfunction and stiffening of the conduit arteries in ESRD patients compared with high-flux HD. HDF decreases uraemic toxins, vascular inflammation, and is associated with subsequent improvement in eNOS functionality. These results suggest that reduced endothelial dysfunction may be an intermediate mechanism explaining the beneficial outcomes associated with HDF.
An 80-year-old female presented to our tertiary care center with a 2-year history of unilateral aural fullness and hearing loss. On review of symptoms, she denied tinnitus, dizziness, trismus, and ...arthralgia of the temporomandibular joint (TMJ). Her past medical history was significant for end-stage renal disease (ESRD) secondary to polycystic kidney disease, for which she has been receiving dialysis for the past 10 years, in addition to hyperlipidemia and hypothyroidism. Her past surgical and social history were noncontributory. Otomicroscopy revealed a tan-brown doughnut-shaped lesion on the anterior auditory canal adjacent to the tympanic membrane (TM) with a core of desquamated skin.
Summary
The interplay between hepatitis B (HBV) and delta (HDV) viruses is complex and not always characterized during chronic HDV infection. We assessed the clinical usefulness of new quantitative ...assays for HBV and HDV serum markers in a retrospective cross‐sectional study. Sera obtained from 122 HDV genotype 1 and HBV genotype D coinfected, anti‐HIV‐negative patients (71 males; median age 49.8 21.7‐66.9 years), recruited consecutively in two geographical areas (Italy 69 patients, Romania 53 patients) with different HBV and HDV epidemiology, were tested for HBsAg, HBV‐DNA, HBcrAg, total anti‐HBc, HDV‐RNA, IgM and total anti‐HDV using quantitative assays. Cirrhosis, which showed comparable prevalence in the two cohorts, was diagnosed in 97 of 122 (79.5%) patients. At multivariate analysis, cirrhosis was associated with lower total anti‐HBc/IgM anti‐HDV ratio (OR 0.990, 95% CI 0.981‐0.999, P = .038), whereas disease activity was associated with higher total anti‐HDV (OR 10.105, 95% CI 1.671‐61.107, P = .012) and HDV‐RNA levels (OR 2.366, 95% CI 1.456‐3.844, P = .001). HDV‐RNA serum levels showed a positive correlation with HBV‐DNA (ρ = 0.276, P = .005), HBsAg (ρ = 0.404, P < .001) and HBcrAg (ρ = 0.332, P < .001). The combined quantitative profiling of HBV and HDV serum markers identifies specific patterns associated with activity and stage of chronic hepatitis D (CHD). HDV pathogenicity depends on the underlying active HBV infection in spite of the inhibition of its replication. HDV‐RNA, IgM anti‐HDV, total anti‐HDV, total anti‐HBc, HBsAg and HBcrAg serum levels qualify for prospective studies to predict progressive CHD and identify candidates to antiviral therapy.
Study of bound and resonant states of NS molecule in the R-matrix approach Iacob, Felix; Meltzer, Thomas; Mezei, János Zsolt ...
Journal of physics. B, Atomic molecular and optical physics/Journal of physics. B, Atomic, molecular and optical physics,
12/2022, Letnik:
55, Številka:
23
Journal Article
Acute myocarditis is an inflammatory condition that may herald the onset of dilated cardiomyopathy (DCM) or arrhythmogenic cardiomyopathy (ACM). We investigated the frequency and clinical ...consequences of DCM and ACM genetic variants in a population-based cohort of patients with acute myocarditis.
This was a population-based cohort of 336 consecutive patients with acute myocarditis enrolled in London and Maastricht. All participants underwent targeted DNA sequencing for well-characterized cardiomyopathy-associated genes with comparison to healthy controls (n=1053) sequenced on the same platform. Case ascertainment in England was assessed against national hospital admission data. The primary outcome was all-cause mortality.
Variants that would be considered pathogenic if found in a patient with DCM or ACM were identified in 8% of myocarditis cases compared with <1% of healthy controls (
=0.0097). In the London cohort (n=230; median age, 33 years; 84% men), patients were representative of national myocarditis admissions (median age, 32 years; 71% men; 66% case ascertainment), and there was enrichment of rare truncating variants (tv) in ACM-associated genes (3.1% of cases versus 0.4% of controls; odds ratio, 8.2;
=0.001). This was driven predominantly by
-tv in patients with normal LV ejection fraction and ventricular arrhythmia. In Maastricht (n=106; median age, 54 years; 61% men), there was enrichment of rare truncating variants in DCM-associated genes, particularly
-tv, found in 7% (all with left ventricular ejection fraction <50%) compared with 1% in controls (odds ratio, 3.6;
=0.0116). Across both cohorts over a median of 5.0 years (interquartile range, 3.9-7.8 years), all-cause mortality was 5.4%. Two-thirds of deaths were cardiovascular, attributable to worsening heart failure (92%) or sudden cardiac death (8%). The 5-year mortality risk was 3.3% in genotype-negative patients versus 11.1% for genotype-positive patients (
=0.08).
We identified DCM- or ACM-associated genetic variants in 8% of patients with acute myocarditis. This was dominated by the identification of
-tv in those with normal left ventricular ejection fraction and
-tv in those with reduced left ventricular ejection fraction. Despite differences between cohorts, these variants have clinical implications for treatment, risk stratification, and family screening. Genetic counseling and testing should be considered in patients with acute myocarditis to help reassure the majority while improving the management of those with an underlying genetic variant.
Hybrid nanomaterials fabricated by the heterogeneous integration of 1D (carbon nanotubes) and 2D (graphene oxide) nanomaterials showed synergy in electrical and mechanical properties. Here, we ...reported the infiltration of carboxylic functionalized single-walled carbon nanotubes (C-SWNT) into free-standing graphene oxide (GO) paper for better electrical and mechanical properties than native GO. The stacking arrangement of GO sheets and its alteration in the presence of C-SWNT were comprehensively explored through scanning electron microscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction. The C-SWNTs bridges between different GO sheets produce a pathway for the flow of electrical charges and provide a tougher hybrid system. The nanoscopic surface potential map reveals a higher work function of the individual functionalised SWNTs than surrounded GO sheets showing efficient charge exchange. We observed the enhanced conductivity up to 50 times and capacitance up to 3.5 times of the hybrid structure than the GO-paper. The laminate of polystyrene composites provided higher elastic modulus and mechanical strength when hybrid paper is used, thus paving the way for the exploitation of hybrid filler formulation in designing polymer composites.
PDF
