Some achiral cyanine dyes form well-ordered chiral assemblies exhibiting pronounced Circular Dichroism (CD) and Circularly Polarized Luminescence (CPL). Notably, achiral C8O3 cyanines self-assemble into tubular J-aggregates, which further organize into bundles displaying bisignate CD spectrum - hallmark of an exciton coupled system - and an unusual bisignated CPL. In contrast, the tubular aggregates display a monosignate CD spectrum.
View Article and Find Full Text PDFThis paper investigates the possibility of realizing ice sensors based on the electrical response of thin strips made from pressed graphene nano-platelets. The novelty of this work resides in the use of the same graphene strips that can act as heating elements via the Joule effect, thus opening the route for a combined device able to both detect and remove ice. A planar capacitive sensor is designed and fabricated, in which the graphene strip acts as one of the armatures.
View Article and Find Full Text PDFNanothermometers are emerging probes as biomedical diagnostic tools. Especially appealing are nanoprobes using NIR light in the range of biological transparency window (BTW) since they have the advantages of a deeper penetration into biological tissues, better contrast, reduced phototoxicity and photobleaching. This article reports the preparation and characterization of organic nanoparticles (ONPs) doped with two polychlorinated trityl radicals (TTM and PTM), as well as studies of their electronic and optical properties.
View Article and Find Full Text PDFThe current work focuses on the investigation of two functionalized naphthyridine derivatives, namely ODIN-EtPh and ODIN-But, to gain insights into the hydrogen bond-assisted H-aggregate formation and its impact on the optical properties of ODIN molecules. By employing a combination of X-ray and electron crystallography, absorption and emission spectroscopy, time resolved fluorescence and ultrafast pump-probe spectroscopy (visible and infrared) we unravel the correlation between the structure and light-matter response, with a particular emphasis on the influence of the polarity of the surrounding environment. Our experimental results and simulations confirm that in polar and good hydrogen-bond acceptor solvents (DMSO), the formation of dimers for ODIN derivatives is strongly inhibited.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
June 2023
Aggregates of cyanine dyes are currently investigated as promising materials for advanced electronic and photonic applications. The spectral properties of aggregates of cyanine dyes can be tuned by altering the supramolecular packing, which is affected by the length of the dye, the presence of alkyl chains, or the nature of the counterions. In this work, we present a joint experimental and theoretical study of a family of cyanine dyes forming aggregates of different types according to the length of the polymethinic chain.
View Article and Find Full Text PDFIn this tutorial, we guide the reader through two alternative approaches to the calculation of circular dichroism (CD) spectra of chiral supramolecular assemblies of non-chiral chromophores. The two seemingly different approaches rely on the same basic approximations and are therefore expected to lead to similar results. For a dimer, we obtain explicit analytic expressions for the CD responses in the two approaches and demonstrate the perfect equivalence of the two methods.
View Article and Find Full Text PDFThis study aims to assess mobile technology use (cell phones and smartphones), level of digital addiction, and the association of these factors with physical, mental and social health and quality of life (QOL) in community-dwelling older adults. A population-based study of a city with a low-income population in Brazil was carried out. Sociodemographics, cognition(MMSE), mental health(DASS-21), QOL(WHOQOL-bref), sleep quality(Pittsburgh Index), instrumental activities of daily living(Lawton), loneliness(UCLA), digital addiction(Internet Addiction Test) and cell phone/smartphone use were investigated.
View Article and Find Full Text PDFThis paper studies the temperature dependence of the electrical resistivity of low-cost commercial graphene-based strips, made from a mixture of epoxy and graphene nanoplatelets. An equivalent homogenous resistivity model is derived from the joint use of experimental data and simulation results obtained by means of a full three-dimensional (3D) numerical electrothermal model. Three different types of macroscopic strips (with surface dimensions of cm) are analyzed, differing in their percentage of graphene nanoplatelets.
View Article and Find Full Text PDFThermally-activated delayed fluorescence (TADF) is a promising strategy to harvest triplets in OLED towards improved efficiency, but several issues must be addressed to fully exploit its potential, including the nature of involved excited singlet and triplet states and their response to the local environment in order to concurrently optimize the dye inside the matrix. Towards this ambitious aim, we present an extensive spectroscopic study of a typical TADF dye in liquid and glassy solvents. TD-DFT results for the same molecule in gas-phase and under an applied electric field are exploited to build a reliable model for the dye, rigorously validated against experiment.
View Article and Find Full Text PDFNuclear Magnetic Resonance (NMR) is an analytical technique extensively used in almost every chemical laboratory for structural identification. This technique provides statistically equivalent signals in spite of using spectrometer with different hardware features and is successfully used for the traceability and quantification of analytes in food samples. Nevertheless, to date only a few internationally agreed guidelines have been reported on the use of NMR for quantitative analysis.
View Article and Find Full Text PDFAnticancer drug efficacy might be leveraged by strategies to target certain biochemical adaptations of tumors. Here we show how depriving cancer cells of glutamine can enhance the anticancer properties of 3-bromopyruvate, a halogenated analog of pyruvic acid. Glutamine deprival potentiated 3-bromopyruvate chemotherapy by increasing the stability of the monocarboxylate transporter-1, an effect that sensitized cells to metabolic oxidative stress and autophagic cell death.
View Article and Find Full Text PDFBackground: Cardiac troponins are emerging as important prognostic markers in chronic cardiovascular conditions like stable coronary artery disease or chronic heart failure (HF). Less is known about the relation between serial measurements of high-sensitivity cardiac troponin T (hs-cTnT) and future events in HF. We determined the association between changes over time in hs-cTnT and outcome in patients with chronic HF.
View Article and Find Full Text PDFBackground: Left atrial (LA) dilation precedes or appears early after the onset of atrial fibrillation (AF) and factors in perpetuating the arrhythmia. Angiotensin receptor blockers were proposed for reversing LA remodeling. We evaluated the effect of valsartan on LA remodeling in patients with a recent episode of AF and the effect of LA size on AF recurrence (AFr).
View Article and Find Full Text PDFBackground: Inflammation may play a significant role in the pathogenesis of atrial fibrillation (AF).
Objectives: To examine the roles of three systemic inflammatory markers in predicting recurrent AF.
Methods: The association between the plasma concentrations of high-sensitivity C reactive protein (hsCRP), interleukin-6 (IL-6) and pentraxin-3 (PTX3) with echocardiographic parameters and with the time to first recurrence of AF was tested in 382 patients with a history of AF but in sinus rhythm at randomisation, enrolled in the GISSI-AF biohumoral study.
J Agric Food Chem
October 2008
The principal applications of high-resolution solid-state NMR spectroscopy, in the field of food science, are reviewed, after a short general introduction, mainly focusing on the potential of these investigations, which are, today, routine tools for resolving technological problems. Selected examples of the applications in the field of food science of high-resolution solid-state NMR spectroscopy both in (13)C and in (1)H NMR particularly illustrative of the results obtainable are reported in some detail.
View Article and Find Full Text PDFBackground: Several studies have found that measurement of blood pressure (BP) in the clinical setting may lead to overestimation of hypertension and may yield inaccurate assessments of the efficacy of antihypertensive treatment.
Objective: The aim of this study was to determine whether the use of clinic BP in the Valsartan and Amlodipine for the Treatment of Isolated Systolic Hypertension in the Elderly (Val-Syst) study accurately identified those elderly outpatients with systolic hypertension who had true 24-hour elevations in BP, as well as those who required dose increases in antihypertensive therapy during follow-up.
Methods: In Val-Syst, patients aged between 60 and 80 years with a clinic sitting systolic BP (SBP) of 160 to 220 mm Hg and a diastolic BP <90 mm Hg after a 2-week placebo washout period were randomized to receive valsartan 80 mg or amlodipine 5 mg once daily (level 1).
Background: The goal of antihypertensive therapy is to provide good blood pressure (BP) control without eliciting adverse effects.
Objective: This study compared the risk-benefit profile of the angiotensin II receptor blocker valsartan with that of the angiotensin-converting enzyme inhibitor lisinopril in patients with mild to severe hypertension. The primary objective was to show that the equipotent BP-lowering effect of the valsartan-based treatment is accompanied by a better tolerability profile.
Background: In chronic heart failure (CHF), the derangement of autonomic nervous system activity has a deep impact on the progression of the disease. It has been demonstrated that modulation of the renin-angiotensin aldosterone system (RAAS) increases autonomic control of heart rate and reduces adrenergic activity. We sought to evaluate, in CHF, the different effects of an ACE inhibitor (lisinopril) and of an AT1 receptor antagonist (valsartan) on heart rate variability, baroreflex sensitivity and norepinephrine plasma levels.
View Article and Find Full Text PDFAfter an episode of unstable angina or myocardial infarction, a high proportion of patients show biochemical signs of coagulation activation, expressed as persistently elevated thrombin generation, in their blood. It is not known whether this has any influence on long-term outcome. In this prospective multicenter cohort study, we assessed the relation of persistently elevated thrombin generation to outcome in 319 consecutive patients with acute coronary syndromes enrolled in the Global Use of Strategies To Open occluded coronary arteries (GUSTO) IIb trial.
View Article and Find Full Text PDFBackground: Proteinuria predicts renal disease progression, and its reduction by angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor antagonists (ARA) is renoprotective.
Methods: In this prospective, randomized, cross-over study of 24 patients with nondiabetic, chronic nephropathies, we compared the effects on proteinuria, renal hemodynamics, and glomerular permselectivity of 8 weeks with comparable blood pressure control achieved by benazepril (10 mg/day) and valsartan (80 mg/day) combined therapy with those achieved by benazepril (20 mg/day) or valsartan (160 mg/day) alone.
Results: Despite comparable changes in blood pressure and glomerular filtration rate (GFR), combined therapy decreased proteinuria more than benazepril (-56% vs.
Objective: To compare the efficacy and tolerability of benazepril 10 mg + amlodipine 5 mg combination (BZ+AM) versus captopril 50 mg + hydrochlorothiazide 25 mg (CP+HT) combination.
Material: 405 outpatients with mild-to-moderate arterial hypertension not adequately controlled by a monotherapy with ACE inhibitors or calcium channel blockers or diuretics entered this multicenter, double-blind, randomized, parallel-group study.
Method: After a 2-week placebo run-in, 397 patients with sitting diastolic (D) blood pressure (BP) > 95 mmHg and/or sitting systolic (S) BP > 160 mmHg were randomized to receive either BZ+AM (201 patients) or CP+HT (196 patients) once daily for 12 weeks.
Objective: The aim of this study was to measure the time-effect profiles of a once-daily administered valsartan/hydrochlorothiazide combination and amlodipine on blood pressure using various indices derived from 24-h ambulatory blood pressure (BP) monitoring.
Methods: Of the 310 randomized outpatients with uncomplicated mild-to-moderate primary hypertension, 259 (133 on valsartan/hydrochlorothiazide, 126 on amlodipine) were eligible for analysis. After a 2-week placebo wash-out period, the patients were randomly allocated to treatment with either valsartan 80 mg once daily (o.
Objective: To compare the antihypertensive efficacy and tolerability of a once-daily fixed valsartan/hydrochlorothiazide (HCTZ) combination and amlodipine in subjects with mild-to-moderate hypertension.
Subjects And Setting: In this multicentre, double-blind, randomized, comparative trial, 690 patients with sitting systolic blood pressure (BP) > or = 160 mmHg and sitting diastolic BP > or = 95 mmHg at the end of a 2-week placebo wash-out period were randomized to valsartan-based treatment (n = 342) or amlodipine (n = 348).
Methods: The patients received valsartan 80 mg o.
The solid-state (13)C CP MAS NMR technique has the potential of monitoring the chemical composition in the solid state of an intact food sample. This property has been utilized to study mushrooms of different species (Pleurotus ostreatus, Pleurotus eryngii, Pleurotus pulmunarius, and Lentinula edodes), already characterized by chemical analyses for protein and dietary fiber components. Solid-state (13)C CP MAS NMR spectroscopy reveals a large difference in the ratio between the glucidic and the proteic resonances probably depending on the mushroom species.
View Article and Find Full Text PDFIn patients with unstable angina, intravenous heparin reduces thrombin activity but does not influence thrombin generation. Recombinant hirudin, a direct thrombin inhibitor, may be more effective in inhibiting both thrombin generation and activity. We measured the plasma levels of prothrombin fragment 1+2 (a marker of thrombin generation) and fibrinopeptide A (a marker of thrombin activity) in 67 patients with unstable angina enrolled in the GUSTO (Global Use of Strategies to Open Occluded Coronary Arteries) IIb trial who were receiving either recombinant hirudin (31 patients) or heparin (36 patients).
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