Associations of Brachial-Ankle Pulse Wave Velocity With Left Ventricular Geometry and Diastolic Function in Untreated Hypertensive Patients

Background: Although brachial-ankle pulse wave velocity (baPWV) is simple and convenient, its usefulness as an initial screening test for hypertensive patients is not well-known. This study aimed to investigate the association of baPWV with left ventricular (LV) geometry and diastolic function in treatment-naive hypertensive patients.

Methods: A total of 202 untreated hypertensive patients (mean age, 62 years; males, 51.5%) without documented cardiovascular diseases were prospectively enrolled. Both baPWV and transthoracic echocardiography were performed on the same day before antihypertensive treatment.

Results: In multiple linear regression analysis after adjustment for potential confounders, baPWV had significant correlations with structural measurements of LV including relative wall thickness (β = 0.219, P = 0.021) and LV mass index (β = 0.286, P = 0.002), and four diastolic parameters including septal e′ velocity (β = −0.199, P = 0.018), E/e′ (β = 0.373, P < 0.001), left atrial volume index (β = 0.334, P < 0.001), and maximal velocity of tricuspid regurgitation (β = 0.401, P < 0.001). The baPWV was significantly increased in patients with LV hypertrophy, abnormal LV remodeling, or diastolic dysfunction, compared to those without (P = 0.008, P = 0.035, and P < 0.001, respectively). In the receiver operating characteristic curve analysis, the discriminant ability of baPWV in predicting LV hypertrophy and diastolic dysfunction had an area under the curve of 0.646 (95% confidence interval 0.544–0.703, P = 0.004) and 0.734 (95% confidence interval 0.648–0.800, P < 0.001), respectively.

Conclusion: baPWV was associated with parameters of LV remodeling and diastolic function in untreated hypertensive patients. The baPWV could be a useful screening tool for the early detection of adverse cardiac features among untreated hypertensive patients.

Nano-porous structuresviaself-assembly of amphiphilic triblock copolymers: influence of solvent and molecular weight

Self-assembly of ABA triblock copolymer micelles into porous materials which are subsequently used as filtration membranes.

Phase transfer of TiO2 nanoparticles from water to ionic liquid triggered by phosphonic acid grafting

Controlling the interface between TiO₂ nanocrystals and ionic liquids is of high fundamental and applied interest for energy storage and conversion devices. Phase transfer of nanoparticles from a synthesis medium to a processing or an application medium plays a significant role in nanotechnology. Here we demonstrate that surface modification with phosphonic acids bearing cationic end-groups can trigger the phase transfer of TiO₂ nanoparticles from an aqueous sol to a typical water-immiscible ionic liquid, [Emim][NTf₂]. The transfer involves both the grafting of the phosphonic acid moiety and the exchange of the counter ion of the cationic end-group by NTf₂ anions, as demonstrated by solid-state NMR, elemental analysis and independent grafting and ion exchange experiments. Furthermore, the colloidal stability of the TiO₂ sols in [Emim][NTf₂] strongly depends on the hydrophobic character of the cationic end-groups.

Effect of charge inhomogeneity and mobility on colloid aggregation

The aggregation of inhomogeneously charged colloids with the same average charge is analyzed using Monte Carlo simulations. We find aggregation of colloids for sizes in the range 10-200 nm, which is similar to the range in which aggregation is observed in several experiments. The attraction arises from the strongly correlated electrostatic interactions associated with the increase in the counterion density in the region between the particles; this effect is enhanced by the discreteness and mobility of the surface charges. Larger colloids attract more strongly when their surface charges are discrete. We study the aggregation as functions of the surface charge density, counterion valence, and volume fraction.

Tailoring of Transition Metal Alkoxides Via complexation For The Synthesis of Hybrid Organic-Inorganic Sols and Gels

The chemical control of hydrolysis-condensation reactions of transition metal alkoxides can be performed through the modification of the transition metal coordination sphere by using strong complexing ligands (SCL). Complexing organic groups can be bonded to the transition metal oxide network in two different ways, as network modifiers or network formers. Different illustrations of the role of complexing ligands on Ti(IV) and Zr(IV) alkoxides are presented. As a network modifier, SCL act as termination agents for condensation reactions allowing a control of particle growth. The complexing ligands being located at the periphery of the oxo core open many opportunities for colloid surface protection. SCL carrying organofunctional groups which exhibit non linear optical (NLO) properties have also been used as probes to study sol-gel transformations. SCL functionalized with organic polymerizable functions act as network formers. Hybrid organic-inorganic copolymers intimately interpenetrated on a nanometer size scale were synthesized from zirconium oxo polymers chemically bonded to polymeric methacrylate chains via a complexing function.

Behavior of adhesive boundary lubricated surfaces under shear: effect of grafted diblock copolymers

The shear behavior and the normal interaction between mica surfaces covered by surfactant or surfactant-polymer mixtures were studied with a Surface Forces Apparatus (SFA) nanotribometer. If the surfaces are compressed while fully immersed in an aqueous surfactant solution that adsorbs in the form of flat bilayers, hemifusion can be induced. When the hemifused surfaces are subject to shear, at least five different dynamic regimes can be recognized. The general behavior may be described by a model based on the kinetics of formation and rupture of adhesive bonds between the shearing surfaces, with an additional viscous term. Once the adsorbed surfactant layer is decorated with physigrafted copolymers, the number of sliding regimes may be reduced to only one, in which the shear stress increases sublinearly with the driving velocity. The adhesion energy and the resistance to hemifusion of the adsorbed surfactant-polymer layers are also strongly modified as the grafting density increases.

Improved immobilization yields by addition of protecting agents in glutaraldehyde-induced immobilization of protease

The effects of peptides and polyethylene glycol (PEG) on the immobilization of protease using glutaraldehyde-activated Lewatit R258-K resin were investigated. When soy peptide was added at 0.1 g/l, the activity recovery and effectiveness factor increased by 20% and 38%, respectively. When PEG4000 (0.5 g/l) was used as a protecting agent, the activity recovery and effectiveness factor were improved by 35% and 60%, respectively, leading to an increased specific activity of the immobilized enzyme. The addition of PEG4000 is suggested to improve the cost-effectiveness for the production of immobilized enzymes.

Optimizing albunex in the left ventricle: an analysis of the technical parameters of four ultrasound systems in canines and humans

Albunex, an intravascular ultrasound contrast agent, has been used clinically to enhance echocardiographic images. The purpose of this study if (1) to determine whether varying the settings on commercially available ultrasound machines has an effect on left ventricular opacification after intravenously administered Albunex and if there is an effect on left ventricular opacification and (2) to determine the ideal settings for each ultrasound scanner. Six canine hearts were imaged with 1 ml injections of intravenously administered Albunex while varying the transducer frequency, preprocessing curves, postprocessing curves, and dynamic range on a variety of ultrasound units. Subsequently 50 human subjects underwent imaging with the various machines while the dynamic range and transducer frequencies were altered. All subjects received two or three intravenous injections of 10 ml Albunex. The opacification of the left ventricular cavitary images in both parts of the study were interpreted visually on a scale of 0 to 4 (0 = none, 1 = trace, 2 = moderate, 3 = dense, and 4 = ideal) by four observers. The maximum compression and transducer frequency of 3.5 MHz showed significant improvement of left ventricular opacification in both canines and humans. These studies have shown that (1) varying the ultrasound unit's parameters affects the quality of left ventricular imaging when Albunex is used to enhance the image, and (2) higher compression and a transducer frequency of 3.5 MHz tend to enhance Albunex images of canine and human hearts.