Cholesteric liquid crystals are frequently produced by the addition of chiral dopants to achiral nematic hosts. We report here the synthesis and performance of chiral dopants obtained from ...bio-betulin produced by a fermentation process. An important aspect of this work is to point out that the fermentation process used to obtain the starting materials is much easier and cheaper when carried out in large volumes than isolating it from the natural product. The performance of the dopants obtained from bio-betulin is indistinguishable from those obtained from commercially available synthetic betulin.
Broken symmetry of any kind in natural or synthetic systems is a burgeoning area of science. In this article, the temporal behavior of the bulk density, electric potential inside the sample, and the ...adsorbed ionic particles density in an electrolytic cell are shown to be non-symmetric and strongly affected by the surfaces dynamics. These parameters are analytically calculated by considering electrodes surfaces with non-identical adsorption-desorption phenomena. The system is submitted to an applied external voltage in the limit of small amplitude, where the time scales involved allow strong surface effects. The influence of the surfaces on the ionic distribution is performed in the framework of the Poisson-Nernst-Planck model by taking into account non-identical boundary conditions on the electrodes and on the electric potential, described by distinct kinetic equations. Such approach may be directly applied to explain strong surface dependence on the impedance spectroscopy, in hybrid aligned liquid crystal cells, fuel cells, biological and condensed matter systems in general.
•Diffusion of ions with non-identical adsorption in electrolytic cell•Under AC field, the voltage, surface and bulk distributions are analytically calculated.•Symmetry breaking in all the distributions due to different ratios of adsorption-desorption•Results more closely related to the experimental situation
Abstract Background Despite antihypertensive therapy, it is difficult to maintain optimal systemic blood pressure (BP) values in hypertensive patients (HPT). Exercise may reduce BP in untreated HPT. ...However, evidence regarding its effect in long-term antihypertensive therapy is lacking. Our purpose was to evaluate the acute effects of 40-minute continuous (CE) or interval exercise (IE) using cycle ergometers on BP in long-term treated HPT. Methods Fifty-two treated HPT were randomized to CE ( n = 26) or IE ( n = 26) protocols. CE was performed at 60% of reserve heart rate (HR). IE alternated consecutively 2 min at 50% reserve HR with 1 min at 80%. Two 24-h ambulatory BP monitoring were made after exercise (postexercise) or a nonexercise control period (control) in random order. Results CE reduced mean 24-h systolic (S) BP (2.6 ± 6.6 mm Hg, p = 0.05) and diastolic (D) BP (2.3 ± 4.6, p = 0.01), and nighttime SBP (4.8 ± 6.4, p < 0.001) and DBP (4.6 ± 5.2 mm Hg, p = 0.001). IE reduced 24-h SBP (2.8 ± 6.5, p = 0.03) and nighttime SBP (3.4 ± 7.2, p = 0.02), and tended to reduce nighttime DBP ( p = 0.06). Greater reductions occurred in higher BP levels. Percentage of normal ambulatory BP values increased after CE (24-h: 42% to 54%; daytime: 42% to 61%; nighttime: 61% to 69%) and IE (24-h: 31% to 46%; daytime: 54% to 61%; nighttime: 46% to 69%). Conclusion CE and IE reduced ambulatory BP in treated HPT, increasing the number of patients reaching normal ambulatory BP values. These effects suggest that continuous and interval aerobic exercise may have a role in BP management in treated HPT.
Even with anti-hypertensive therapy, it is difficult to maintain optimal systemic blood pressure values in hypertensive patients. Exercise may reduce blood pressure in untreated hypertensive, but its ...effect when combined with long-term anti-hypertensive therapy remains unclear. Our purpose was to evaluate the acute effects of a single session of aerobic exercise on the blood pressure of long-term-treated hypertensive patients.
Fifty treated hypertensive patients (18/32 male/female; 46.5±8.2 years; Body mass index: 27.8±4.7 kg/m2) were monitored for 24 h with respect to ambulatory (A) blood pressure after an aerobic exercise session (post-exercise) and a control period (control) in random order. Aerobic exercise consisted of 40 minutes on a cycle-ergometer, with the mean exercise intensity at 60% of the patient’s reserve heart rate.
Post-exercise ambulatory blood pressure was reduced for 24 h systolic (126±8.6 vs. 123.1±8.7 mmHg, p=0.004) and diastolic blood pressure (81.9±8 vs. 79.8±8.5 mmHg, p=0.004), daytime diastolic blood pressure (85.5±8.5 vs. 83.9±8.8 mmHg, p=0.04), and nighttime S (116.8±9.9 vs. 112.5±9.2 mmHg, p<0.001) and diastolic blood pressure (73.5±8.8 vs. 70.1±8.4 mmHg, p<0.001). Post-exercise daytime systolic blood pressure also tended to be reduced (129.8±9.3 vs. 127.8±9.4 mmHg, p=0.06). These post-exercise decreases in ambulatory blood pressure increased the percentage of patients displaying normal 24h systolic blood pressure (58% vs. 76%, p=0.007), daytime systolic blood pressure (68% vs. 82%, p=0.02), and nighttime diastolic blood pressure (56% vs. 72%, p=0.02). Nighttime systolic blood pressure also tended to increase (58% vs. 80%, p=0.058).
A single bout of aerobic exercise reduced 24h ambulatory blood pressure levels in long-term-treated hypertensive patients and increased the percentage of patients reaching normal ambulatory blood pressure values. These effects suggest that aerobic exercise may have a potential role in blood pressure management of long-term-treated hypertensive.
We present the biochemical and functional characterization of Bothropoidin, the first haemorrhagic metalloproteinase isolated from Bothrops pauloensis snake venom. This protein was purified after ...three chromatographic steps on cation exchange CM-Sepharose fast flow, size-exclusion column Sephacryl S-300 and anion exchange Capto Q. Bothropoidin was homogeneous by SDS-PAGE under reducing and non-reducing conditions, and comprised a single chain of 49,558 Da according to MALDI TOF analysis. The protein presented an isoelectric point of 3.76, and the sequence of six fragments obtained by MS (MALDI TOF\TOF) showed a significant score when compared with other PIII Snake venom metalloproteinases (SVMPs). Bothropoidin showed proteolytic activity on azocasein, Aα-chain of fibrinogen, fibrin, collagen and fibronectin. The enzyme was stable at pH 6-9 and at lower temperatures when assayed on azocasein. Moreover, its activity was inhibited by EDTA, 1.10-phenanthroline and β-mercaptoethanol. Bothropoidin induced haemorrhage minimum haemorrhagic dose (MHD) = 0.75 µg, inhibited platelet aggregation induced by collagen and ADP, and interfered with viability and cell adhesion when incubated with endothelial cells in a dose and time-dependent manner. Our results showed that Bothropoidin is a haemorrhagic metalloproteinase that can play an important role in the toxicity of B. pauloensis envenomation and might be used as a tool for studying the effects of SVMPs on haemostatic disorders and tumour metastasis.
Abstract Purpose Beta-blockers (BB) have shown to improve outcomes among heart failure patients (HF). Adequate risk stratification is still a major concern for HF. The prognostic indexes have been ...detected, but only few parameters maintain consistently high power in predicting progression of disease and mortality. Peak oxygen consumption (VO2 peak, ml kg − 1 min − 1 ) is traditionally used for risk stratification in HF, however, there is limited evidence regarding predictive value of VO2 peak in patients taking BB. Methods Two hundred twenty nine patients, aged 49 ± 13 years with diagnosed HF for more than 6 months due to ischemic ( n = 73), idiopathic dilated ( n = 149) and Chagas disease ( n = 7) underwent a cardiopulmonary exercise test (CPX). The ejection fraction was 38 ± 10%; clinical stability was defined as no change in the NYHA class or absence of hospitalization for heart failure and stable medical treatment during 3 months prior to CPX. Subjects were tracked for cardiac-related mortality after CPX. Results The mean follow-up period was 2.5 ± 1.1 years and means value for VO2 peak was 16.3 ± 4. Current BB therapy included carvedilol (83.4%), metoprolol (7.8%), bisoprolol (3.9%) and others (4.8%). The area under the ROC curve for VO2 peak was 0.80 (95% CI: 0.69–0.90, optimal threshold: 12.5 and 82% sensitivity/26% specificity, p < 0.001). Kaplan–Meier analysis that revealed event-free survival for subjects in < and > 12.5 was 28% and 2.8%, respectively (long-rank 34.8; p < 0.001). Conclusions VO2 peak seems to maintain prognostic value in HF patients BB therapy. The present study also provides new evidence that optimal threshold value for VO2 peak in the BB era is 12.5 ml kg − 1 min − 1.
Right ventricular (RV) dysfunction remains one of the most prominent complications during the period immediately after heart transplantation (HT); however, late adaptation of the RV has not been well ...described. The aim of our study was to evaluate RV function and remodeling using magnetic resonance imaging (MRI) and to correlate it with exercise capacity and also with hemodynamic data obtained before HT.
We prospectively evaluated RV function of 25 heart-transplanted patients, without cardiac allograft vasculopathy, who were documented by negative dobutamine stress echocardiography during late follow-up (Group 1, 6 +/- 4.3 years) using MRI. We then compared Group 1 with a control group consisting of 10 patients, who were < or =1 year post-HT (Group 2), hemodynamically stable, and with the same pre-operative hemodynamic features as Group 1. Their pulmonary arterial systolic blood pressure (PSBP) varied from 17 to 67 mm Hg (43.2 +/- 15.3) and pulmonary vascular resistance (PVR) from 1.0 to 5.4 Wood units (2.5 +/- 1.12). The following parameters were studied: RV end-diastolic volume (EDV) and systolic volume (ESV); stroke volume (SV); ejection fraction (EF); and mass (M). We also evaluated the VO2 peak and slope VE/VCO2 values during a treadmill test. Data were analyzed and correlated with the hemodynamic values of PVR and PSBP obtained pre-HT.
In Group 1, treadmill evaluation data showed exercise VO2 peak (19.9 +/- 3.19 ml/kg/min) and slope VE/VCO2 (36.9 +/- 4.5) values comparable to those of sedentary individuals; RV variables according to MRI were within normal ranges, with the following mean values for Groups 1 and 2, respectively: RVEDV, 99.6 +/- 4.0 ml vs 127 +/- 16 ml (p = 0.03); RVESV, 42 +/- 2 ml vs 58.5 +/- 9 ml (p = 0.01); RVSV, 57 +/- 3 ml vs 71 +/- 10 ml (p = 0.1); RVEF, 58 +/- 1.4% vs 54 +/- 3.8% (p = 0.29); and RVM, 43.4 +/- 1.9 g vs 74 +/- 8.8 g (p = 0.001). There was no correlation between hemodynamic pulmonary values before HT or any other index of late RV performance, including RV remodeling and hypertrophy, in our study population (p = not significant).
In contrast to what we would expect for heart transplant patients at late follow-up, the RV may adapt to pulmonary pressure and resistance, with reverse remodeling characterized by volume and mass reduction, leading to normalization of RV function despite abnormal hemodynamic pulmonary values being measured before HT. There was no influence on the low exercise capacity observed in these patients, in the absence of cardiac allograft vasculopathy.
After heart transplantation patients improve their quality of life. However, they frequently have clinical problems in the post operative period, as physical deconditioning, muscular atrophy, ...weakness and lower maximal aerobic capacity, in part due to the inactivity in the preoperative period and to factors as the difference in donor/receptor body surface, heart denervation, among others. Regular physical activity plays an important role in heart transplanted patients follow-up and should be recommended as soon as possible, may be in predischarge phase, going on after discharge, which could help patients to have a satisfactory life-style, similar to what they had before the disease, returning to active and productive life.
PDF
