10 research outputs found

    A simple architecture with self-assembled monolayers to build immunosensors for detecting the pancreatic cancer biomarker CA19-9

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    Accepted ManuscriptThe challenge of the early diagnosis of pancreatic cancer in routine clinical practice requires low-cost means of detection, and this may be achieved with immunosensors based on electrical or electrochemical principles. In this paper, we report a potentially low-cost immunosensor built with interdigitated gold electrodes coated with a self-assembled monolayer and a layer of anti-CA19-9 antibodies, which is capable of detecting the pancreatic cancer biomarker CA19-9 using electrical impedance spectroscopy. Due to specific, irreversible adsorption of CA19-9 onto its corresponding antibody, according to data from polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS), the immunosensor is highly sensitive and selective. It could detect CA19-9 in commercial samples with a limit of detection of 0.68 U mL−1, in addition to distinguishing between blood serum samples from patients with different concentrations of CA19-9. Furthermore, by treating the capacitance data with information visualization methods, we were able to verify the selectivity and robustness of the immunosensor with regard to false positives, as the samples containing higher CA19-9 concentrations, including those from tumor cells, could be distinguished from those with possible interferents.CAPES, FAPESP (Grant 2013/14262-7 and 2012/15543-7), CNPq (150985/2017-7), nBioNet network and Barretos Cancer Hospital for financial supportinfo:eu-repo/semantics/publishedVersio

    Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

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    Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≄ II, EF ≀35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

    Kinetics of photoinduced birefringence in the guest-host system of poly(methyl methacrylate) doped with azobenzene-containing crown ethers

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    The kinetics of the buildup and decay of photoinduced birefringence was examined in a series of host-guest systems: azobenzene-containing crown ethers, differing in the size of the crowns, dissolved in a poly (methyl methacrylate) matrix. In all samples, the kinetics of the buildup of the birefringence was reasonably described by a sum of two exponential functions, the time constants being inversely proportional to the intensity of the pumping light and the magnitudes of the signals at the saturation level depending on the pumping light intensity and sample thickness. The dark decays were best described by the stretched exponential function, with the characteristic parameters (time constant and stretch coefficient) being practically independent of the type of crown ether. The time constants of the signal decay were orders of magnitude shorter than the respective constants of the dark isomerization of the azo crown ethers, thus indicating that the process controlling the decay was a relaxation of the polymer matrix and/or a rearrangement of the flexible parts of the crowns. (C) 2007 Wiley Periodicals, Inc

    Pencil graphite core for pattern recognition applications

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    Ready-to-use sensing probes have been used to develop a rapid-production, low-cost, fast and sensitive electronic tongue, which consists of electric double-layer microfluidic capacitors. Pencil graphite cores consisting of rough flake-graphite with various ratios of graphite, clay and wax assured differential interactions towards pattern recognition applications55324623462

    Dynamic behavior of surface-enhanced raman spectra for rhodamine 6G interacting with gold nanorods: implication for analyses under wet versus dry conditions

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    We report the dynamic behavior of surface-enhancement Raman scattering (SERS) spectra using rhodamine 6G dye (R6G, 10–8 mol L–1) adsorbed on gold nanorods (AuNRs). SERS spectra displayed a strong time-dependence intensity in wet to dry transition states. FEG-SEM images reveal a stacking of AuNRs organization that can lead to Raman signal improvements due to the formation of a 3D hot spot matrix that acts as a trap for target molecules. AuNRs nanostructured films were efficiently employed to form SERS substrates. The independent random AuNR organization in the SERS spectra exhibits a characteristic profile of intensities due to different dielectric environmental conditions. Despite the variations observed in the spectra array, a pattern was recognized by statistical analysis. Multidimensional analysis ensured the distinction of the study’s requirements applied to the SERS response, exhibiting a silhouette coefficient of 0.92 with the least-squares projection technique. Changes in the SERS spectra profile from wet to dry state conditions of R6G dye solution can be interpreted as the dynamic behavior of R6G molecules correlated to distinct molecular adsorption and (or) surface distribution of the R6G molecules proving different plasmonic resonances. Simulations obtained from BEM calculation in experimental data corroborate that the SERS enhancement is strongly dependent on the nanoparticle coupling in nanoscale and the dielectric environment3881388147CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP150003/2016-1; 408985/2016-0; 407592/ 2016-888887.333739/2019-002013/22127-2; 2016/21070-

    Cardiac myosin activation with omecamtiv mecarbil in systolic heart failure

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    BACKGROUND The selective cardiac myosin activator omecamtiv mecarbil has been shown to improve cardiac function in patients with heart failure with a reduced ejection fraction. Its effect on cardiovascular outcomes is unknown. METHODS We randomly assigned 8256 patients (inpatients and outpatients) with symptomatic chronic heart failure and an ejection fraction of 35% or less to receive omecamtiv mecarbil (using pharmacokinetic-guided doses of 25 mg, 37.5 mg, or 50 mg twice daily) or placebo, in addition to standard heart-failure therapy. The primary outcome was a composite of a first heart-failure event (hospitalization or urgent visit for heart failure) or death from cardiovascular causes. RESULTS During a median of 21.8 months, a primary-outcome event occurred in 1523 of 4120 patients (37.0%) in the omecamtiv mecarbil group and in 1607 of 4112 patients (39.1%) in the placebo group (hazard ratio, 0.92; 95% confidence interval [CI], 0.86 to 0.99; P = 0.03). A total of 808 patients (19.6%) and 798 patients (19.4%), respectively, died from cardiovascular causes (hazard ratio, 1.01; 95% CI, 0.92 to 1.11). There was no significant difference between groups in the change from baseline on the Kansas City Cardiomyopathy Questionnaire total symptom score. At week 24, the change from baseline for the median N-terminal pro-B-type natriuretic peptide level was 10% lower in the omecamtiv mecarbil group than in the placebo group; the median cardiac troponin I level was 4 ng per liter higher. The frequency of cardiac ischemic and ventricular arrhythmia events was similar in the two groups. CONCLUSIONS Among patients with heart failure and a reduced ejection, those who received omecamtiv mecarbil had a lower incidence of a composite of a heart-failure event or death from cardiovascular causes than those who received placebo. (Funded by Amgen and others; GALACTIC-HF ClinicalTrials.gov number, NCT02929329; EudraCT number, 2016 -002299-28.)

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

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    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

    Erratum to: Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) (Autophagy, 12, 1, 1-222, 10.1080/15548627.2015.1100356

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    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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