Electrofluorochromic Switching of Heat-Induced Cross-Linkable Multi-Styryl-Terminated Triphenylamine and Tetraphenylethylene Derivatives

High-performance electrochromic (EC) and electrofluorochromic (EFC) materials have garnered considerable interest due to their diverse applications in smart windows, optoelectronics, optical displays, military camouflage, etc. While many different EC and EFC polymers have been reported, their preparation often requires multiple steps, and their polymer molecular weights are subjected to batch variation. In this work, we prepared two triphenylamine (TPA)-based and two tetraphenylethylene (TPE)-based derivatives functionalized with terminal styryl groups via direct Suzuki coupling with (4-vinylphenyl)boronic acid and vinylboronic acid pinacol ester. The two novel TPE derivatives exhibited green-yellow aggregation-induced emission (AIE). The EC and EFC properties of pre- and post-thermally treated derivatives spin-coated onto ITO-glass substrates were studied. While all four derivatives showed modest absorption changes with applied voltages up to +2.4 V, retaining a high degree of optical transparency, they exhibited obvious EFC properties with the quenching of blue to yellow fluorescence with IOFF/ON contrast ratios of up to 7.0. The findings therefore demonstrate an elegant approach to preparing optically transparent, heat-induced, cross-linkable styryl-functionalized EFC systems.

Valorization of Spent coffee Grounds: A sustainable resource for Bio-based phase change materials for thermal energy storage

Spent coffee grounds (SCGs) are waste residues arising from the process of coffee brewing and are usually sent to landfills, causing environmental concerns. SCGs contain a considerable amount of fatty acids and is therefore a promising green alternative bio-based phase change material (PCMs) compared to conventional organic and inorganic PCMs. In this study, the extraction of coffee oil from SCGs was conducted using three different organic solvents-ethanol, acetone, and hexane. The chemical composition, chemical, and thermophysical properties of these coffee oil extracts were studied to evaluate their feasibility as a bio-based PCM. Gas chromatography-mass spectroscopy (GC-MS) analysis indicated that coffee oil contains about 60-80 % of fatty acids while the phase transition temperature of the coffee oil extracts is approximately 4.5 ± 0.72 °C, with latent heat values of 51.15 ± 1.46 J/g as determined by differential scanning calorimetry (DSC). Fourier Transform Infrared Spectroscopy (FTIR) and DSC results of coffee oil extracts after thermal cycling revealed good thermal and chemical stability. An application study to evaluate coffee oil extract as a potential cold therapy modality showed that it can maintain temperatures below normal body temperature for up to 46 min. In conclusion, this work exemplifies the potential of SCGs as a promising green and sustainable resource for bio-based PCMs for low-temperature thermal energy storage applications such as cold-chain transportation and cold therapy.

Recent advances in host-guest supramolecular hydrogels for biomedical applications

The recognition-directed host-guest interaction is recognized as a valuable tool for creating supramolecular polymers. Functional hydrogels constructed through the dynamic and reversible host-guest complexation are endowed with a great many appealing features, such as superior self-healing, injectability, flexibility, stimuli-responsiveness and biocompatibility, which are crucial for biological and medicinal applications. With numerous topological structures and host-guest combinations established previously, recent breakthroughs in this area mostly focus on further improvement and fine-tuning of various properties for practical utilizations. The current contribution provides a comprehensive overview of the latest developments in host-guest supramolecular hydrogels, with a particular emphasis on the innovative molecular-level design strategies and hydrogel formation methodologies targeting at a wide range of active biomedical domains, including drug delivery, 3D printing, wound healing, tissue engineering, artificial actuators, biosensors, etc. Furthermore, a brief conclusion and discussion on the steps forward to bring these smart hydrogels to clinical practice is also presented.

Towards modulating the colour hues of isoindigo-based electrochromic polymers through variation of thiophene-based donor groups

This paper demonstrated that the hues of both neutral and oxidised colours of isoindigo-based donor–acceptor polymers could be tuned subtly by means of variation of the number and type of donor groups.

Strategy to Chemically Decorate Nanopores of a Carbon Membrane for Filtrating Polyphenolics from Ethanol

This study invents a post-pyrolysis modification approach to render the resulting carbon membrane (CM) competent for organic solvent nanofiltration (OSN). A bitumen coating on a porous stainless-steel disk (PSD) serves as the precursor for the intended carbon membrane (CM), which is attained through pyrolysis in Ar. The bitumen coating casts dual-pore networks in the CM because of the dominant asphaltene constituent in bitumen. The subsequent chemical decoration of CM was pursued through the following protocol: dopamine (DA) was deployed in the nanopores of CM via pressurized infiltration and followed by Tris buffer passes through to trigger in situ conversion of DA to polydopamine (PDA), which was affixed over the pore walls to furnish chemical affinity (termed as CM_PDA). Additionally, the catechol moiety of PDA was arranged to chelate with the Zn²⁺ ion, aiming to trim the -OH anchor (termed as CM_PDA-Zn) to probe the effect of chelate on separation. The three membranes (CM, CM_PDA, and CM_PDA-Zn) were thereafter assessed by the separation of ethanol or isopropanol from phenolics [tannic acid (TA)/tetracycline (TC)]. A significantly improved OSN performance [rejection (%) ↔ permeance (L/(m²·h·bar))] of CM vs CM_PDA was observed: (i) for TA feed, 13% ↔ 85 L/(m²·h·bar) vs 83% ↔ 12 L/(m²·h·bar); and (ii) for TC feed, 20% ↔ 78 L/(m²·h·bar) vs 78% ↔ 12 L/(m²·h·bar). Compared to CM_PDA, CM_PDA-Zn further advances the rejection performance (∼89% for TA and ∼80% for TC) over 50 h separation. They are benchmarked by the latest literature results. The performance enhancements can be attributed to the spreading of PDA or PDA-Zn sites in the dual-pore networks, so that they are able to offer H-bonding and steric blocking roles, a chemicomechanical effect, to seize solute molecules over pore walls. It is this interfacial drag effect that sustains the solute rejection.

1154FFR guided acute complete revascularization versus culprit lesion only treatment in patients presenting with STEMI and multi vessel disease; final 3-year outcome data from Compare-Acute trial

Background

Compare-Acute trial showed a 1-year superior outcome of FFR-guided acute complete revascularization (FFR-CR) compared to culprit-lesion-only revascularization (CLO) in patients presenting with ST-segment elevation myocardial infarction (STEMI) and multi-vessel disease (MVD). Long-term outcome results are unknown.

Purpose

To evaluate if FFR-CR strategy is superior to CLO strategy in terms of outcome at 3 year follow-up.

Methods

Compare-Acute is a multicenter, investigator-initiated prospective randomized controlled trial that involved 24 sites. Patients with STEMI and MVD were randomized, after successful primary PCI towards FFR-CR or CLO treatment strategies with a 1:2 ratio (295 pts vs 590 pts). All stenosis ≥50% in the non-infarct artery were investigated by FFR in both arms. In the FFR-CR arm, all non-culprit (NC) lesions with a FFR ≤0.80 were treated by PCI. In the CLO arm pts underwent blinded FFR procedure of the NC lesions. Further treatment of these lesions was based on symptoms and/or ischemia testing during follow-up with an allowed treatment window of 45 days. The primary endpoint was defined as a composite of all-cause mortality, non-fatal myocardial infarction, any revascularization and cerebrovascular events (MACCE) at 12 months. The major secondary endpoint is MACCE from both strategies up to 3-year follow-up.

Results

1-year clinical outcomes have already been presented and published. At 36 months the composite end-point of MACCE occurred in 46 patients in the FFR-CR group vs 178 patients in the CLO group (15.6% vs 30.2%; HR 0.46, 95% CI 0.29–0.59; p<0.01), as shown in Fig. 1. The incidence of death (4 pts vs 10 pts; 1.4% vs 1.7%; HR 0.86, 95% CI 0.39–1.8; p=0.71), MI (20 pts vs 53 pts; 7.1% vs 9.3%; HR 0.74, 95% CI 0.44–1.24; p=0.25) and stroke (1 pt vs 7 pts; 0.3% vs 1.2%; HR 0.29, 95% CI 0.03–2.3; p=0.24) was not significantly different in the two groups, but revascularizations were significantly higher in the CLO group: 37 patients in the FFR-CR group vs 149 patients in the CLO group (13.0% vs 26.0%; HR 0.45; 95% CI 0.31–0.64; p<0.01). Furthermore, in a subgroup analysis, when we considered only patients with FFR positive non-culprit lesions in both arms, we found a higher incidence of MI at follow-up in the CLO arm compared to the FFR-CR arm: 30/224 vs 13/194 (13.4% vs 6.7%; p 0.03).

MACCE-free survival at 3 years

Conclusion

With this analysis of the Compare-Acute trial we confirm that the benefit of a FFR-guided complete revascularization strategy in patients with STEMI and MVD is maintained at 3 years of follow-up. This difference is mainly driven by increased revascularizations in the CLO arm, but also by increased incidence of MI in the CLO subgroup with FFR+ lesions that were left untreated.

Tamoxifen is not detrimental to endothelial function in postmenopausal women with breast cancer

BACKGROUND

Tamoxifen has mixed estrogen agonist and antagonist properties in estrogen-regulated tissues. Its effect on the cardiovascular system is not well defined. We carried out a study to investigate the effect of tamoxifen on peripheral vascular endothelial function.

METHODS

Three groups of postmenopausal women (median age, 56 years; range, 39 to 69 years) with breast cancer were studied. Patients in group 1 (n = 10) were newly diagnosed with breast cancer and studied before and after 4 weeks treatment with tamoxifen. Group 2 women (n = 6) had been receiving long-term tamoxifen (3 to 5 years) and were studied while taking tamoxifen and 4 weeks after stopping it. The final group of 6 subjects were in remission from primary breast cancer and were not receiving or had previously received tamoxifen. Ultrasound assessments of endothelial function were done before and 4 weeks after the initiation or discontinuation of tamoxifen with the nontreatment group acting as control. All ultrasound imaging was made by a single investigator blinded to the therapeutic status of the subject. Brachial artery diameter was measured by ultrasound at baseline and 1 minute after reactive hyperemia. Flow-mediated reactivity (FMR) was defined as percent change in artery diameter from baseline 1 minute after reactive hyperemia.

RESULTS

There was no change in FMR in patients before compared with 4 weeks after starting tamoxifen (4.06% +/- 1.44% vs 3.97% +/- 1.20%, respectively, mean +/- standard error of the mean [SEM], P =.97). There was no significant change in FMR on withdrawal from tamoxifen (1.84% +/- 1.98% vs -0.42% +/- 1.44% on tamoxifen vs off tamoxifen, mean +/- SEM, P =.36). FMR in subjects taking tamoxifen was no different from the control group (3.17% +/- 1.05% vs 3.16% +/- 0.91%, respectively, mean +/- SEM, P =.995).

CONCLUSIONS

Tamoxifen does not appear to affect endothelial function in the short term in postmenopausal women with breast cancer.

Effects of storage solutions on in vitro vasoreactivity of radial artery conduits

OBJECTIVES

Surgical preparation of coronary conduits for coronary artery bypass grafting may affect their early and long-term patency; one mechanism may involve endothelial damage. We investigated the effect of 3 commonly used solutions-Ringer's solution, normal saline solution, and heparinized whole blood-on in vitro endothelial and contractile functions of the human radial artery.

METHODS

Radial artery segments were harvested, cut into 3-mm rings, and stored in unoxygenated Ringer's solution, normal saline solution, or heparinized whole blood for 45 minutes. Rings stored in Krebs solution were used as controls. The rings were then mounted and stretched to an optimal resting tension in oxygenated Krebs solution at 37 degrees C. Contraction responses to potassium, norepinephrine, and serotonin and relaxation responses to acetylcholine, verapamil, and nitroprusside were evaluated.

RESULTS

Fifty-six radial artery ring segments from 14 patients (n = 7 rings for each contraction-relaxation curve) were studied. Equilibrated resting tension was 9.6 +/- 0.3 mN (5.9 +/- 0.2 g), and resting internal circumference was 6.4 +/- 0.2 mm. Absolute maximum contraction to potassium was significantly less in rings stored in normal saline solution than in rings stored in control solution (10.7 +/- 0.6 g vs 14.5 +/- 0.6 g, P <.01; 95% confidence intervals, 0.9-6.9). There was no difference in the contraction to norepinephrine (P =.11) and serotonin (P =.25) among the 3 solutions compared with the control solution. Rings stored in heparinized whole blood had significantly greater endothelium-dependent relaxation to acetylcholine (P <.007), whereas those stored in normal saline solution had reduced responses. Endothelium-independent relaxation to verapamil and nitroprusside were similar among the 3 solutions.

CONCLUSION

Heparinized whole blood is a better physiologic medium for preservation of radial artery endothelial and contractile functions during storage before grafting.

Testosterone enhances flow-mediated brachial artery reactivity in men with coronary artery disease

Acute administration of high-dose testosterone in men with coronary artery disease improves endothelial function.

Effect of fat and carbohydrate consumption on endothelial function

Consumption of a meal high in monounsaturated fat was associated with acute impairment of endothelial function when compared with a carbohydrate-rich meal. Such a divergent response in endothelial function may be important in the modulation of vascular function in health and disease.

Thinning of the placental villous membrane during maintenance in hypoxic organ culture: structural adaptation or syncytial degeneration?

This study was undertaken in order to reinvestigate claims that the human placenta is able to adapt structurally under hypoxic stress so as to facilitate materno-fetal oxygen exchange. The results confirmed that thinning of the villous membrane does occur after maintenance for 10 h in an atmosphere of 6% oxygen, and that this effect is partially reversed by maintenance for a further 10 h under normoxic conditions (21% O2). However, throughout these experiments the values for both the arithmetic and the harmonic mean thicknesses of the villous membrane altered in an identical fashion. This indicates that the thinning observed was not the result of redistribution of the syncytiotrophoblast around the villous surface, with movement away from the sites of the fetal capillaries as previously postulated. Rather, it must have been caused by a reduction in the total mass of the syncytium, resulting from either involution and partial degeneration of its organelles, or some form of fluid-shift phenomenon. Whatever the cause, these effects were only partially reversed after further culture for 10 h in well-oxygenated conditions. Thus whilst there is an accumulating body of evidence to suggest that the placenta can adapt structurally to hypoxia in vivo, it is apparent that the in vitro organ culture system is not a suitable model with which to investigate the process.