1,413 research outputs found

    Extracellular cysteine in connexins: Role as redox sensors

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    Indexación: Scopus.Connexin-based channels comprise hemichannels and gap junction channels. The opening of hemichannels allow for the flux of ions and molecules from the extracellular space into the cell and vice versa. Similarly, the opening of gap junction channels permits the diffusional exchange of ions and molecules between the cytoplasm and contacting cells. The controlled opening of hemichannels has been associated with several physiological cellular processes; thereby unregulated hemichannel activity may induce loss of cellular homeostasis and cell death. Hemichannel activity can be regulated through several mechanisms, such as phosphorylation, divalent cations and changes in membrane potential. Additionally, it was recently postulated that redox molecules could modify hemichannels properties in vitro. However, the molecular mechanism by which redox molecules interact with hemichannels is poorly understood. In this work, we discuss the current knowledge on connexin redox regulation and we propose the hypothesis that extracellular cysteines could be important for sensing changes in redox potential. Future studies on this topic will offer new insight into hemichannel function, thereby expanding the understanding of the contribution of hemichannels to disease progression.http://journal.frontiersin.org/article/10.3389/fphys.2016.00001/ful

    6β-Acetamido-5α-hydroxy­cholestan-3β-yl acetate

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    The title steroid, C31H53NO4, was prepared from the corresponding 5α,6α-epoxy­cholestane. The conformation of the six-membered rings is close to a chair form, while the five-membered ring adopts a twist conformation. The hydroxyl and acetamide groups are in axial positions. The nucleophilic species bound to the steroid nucleus at position 6 by the β-face, whereas the hydroxyl group at position 5 has α-orientation. All rings are trans-fused. The crystal packing shows that the mol­ecules related by twofold symmetry exist as O—H⋯O hydrogen-bonded dimers

    Controlled-NOT logic gate for phase qubits based on conditional spectroscopy

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    A controlled-NOT logic gate based on conditional spectroscopy has been demonstrated recently for a pair of superconducting flux qubits [Plantenberg et al., Nature 447, 836 (2007)]. Here we study the fidelity of this type of gate applied to a phase qubit coupled to a resonator (or a pair of capacitively coupled phase qubits). Our results show that an intrinsic fidelity of more than 99% is achievable in 45ns.Comment: 5 pages, 5 figures, To appear in Quantum Inf. Pro

    Chronic wasting disease risk assessment in Portugal: results and future work.

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    Número da Revista Portuguesa de Ciências Veterinárias, dedicado à publicação dos "Proceedings of the 10th Iberian Congress on Prions" que decorreu em Vila Real, Portugal de 19 1 20 de maio de 2022.Chronic wasting disease risk assessment in Portugal: results and future work.This work was supported by the project WastingPrionRisk [POCI-01-0145-FEDER-029947 / PTDC/ CVT-CVT/29947/2017] funded by the Portuguese Foundation for Science and Technology (FCT). FCT PhD grant [SFRH/BD/146961/2019] financed by FCT through FSE (Fundo Social Europeu). This work was also supported by national funds [UIDB/CVT/00772/2020], [LA/P/0059/2020] and [UIDB/04033/2020] by FCT.info:eu-repo/semantics/publishedVersio

    Lack of Neointimal Proliferation After Implantation of Sirolimus-Coated Stents in Human Coronary Arteries: A Quantitative Coronary Angiography and Three-Dimensional Intravascular Ultrasound Study

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    BACKGROUND: Restenosis remains an important limitation of interventional cardiology. Therefore, we aimed to determine the safety and efficacy of sirolimus (a cell-cycle inhibitor)-coated BX Velocity stents. METHODS AND RESULTS: Thirty patients with angina pectoris were electively treated with 2 different formulations of sirolimus-coated stents (slow release [SR], n=15, and fast release [FR], n=15). All stents were successfully delivered, and patients were discharged without clinical complications. Independent core laboratories analyzed angiographic and 3D volumetric intravascular ultrasound data (immediately after procedure and at 4-month follow-up). Eight-month clinical follow-up was obtained for all patients. There was minimal neointimal hyperplasia in both groups (11.0+/-3.0% in the SR group and 10.4+/-3.0% in the FR group, P:=NS) by ultrasound and quantitative coronary angiography (in-stent late loss, 0.09+/-0.3 mm [SR] and -0.02+/-0.3 mm [FR]; in-lesion late loss, 0.16+/-0.3 mm [SR] and -0.1+/-0.3 mm [FR]). No in-stent or edge restenosis (diameter stenosis >or=50%) was observed. No major clinical events (stent thrombosis, repeat revascularization, myocardial infarction, or death) had occurred by 8 months. CONCLUSIONS: The implantation of sirolimus-coated BX Velocity stents is feasible and safe and elicits minimal neointimal proliferation. Additional placebo-controlled trials are required to confirm these promising results

    Chronic wasting disease (CWD) risk assessment in Portugal : The genetic approach to study prion protein gene (PRNP) variability in Portuguese populations of three cervid species: red deer, fallow deer and roe deer.

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    Número da Revista Portuguesa de Ciências Veterinárias, dedicado à publicação dos "Proceedings of the 10th Iberian Congress on Prions" que decorreu em Vila Real, Portugal de 19 1 20 de maio de 2022.Among the transmissible spongiform encephalopathies (TSEs), chronic wasting disease (CWD) in cervids is now the rising concern in wildlife within Europe, after the first case was detected in Norway in 2016, in a wild reindeer and until October 2021, a total of 34 cases were described in Norway, Sweden and Finland.This work was supported by the project WastingPrionRisk [POCI-01-0145-FEDER-029947 / PTDC/ CVT-CVT/29947/2017] funded by the Portuguese Foundation for Science and Technology (FCT). FCT PhD grant [SFRH/BD/146961/2019] financed by FCT through FSE (Fundo Social Europeu). This work was also supported by national funds [UIDB/CVT/00772/2020], [LA/P/0059/2020] and [UIDB/04033/2020] by FCT.info:eu-repo/semantics/publishedVersio

    Sirolimus-eluting stent for the treatment of in-stent restenosis: a quantitative coronary angiography and three-dimensional intravascular ultrasound study

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    BACKGROUND: We have previously reported the safety and effectiveness of sirolimus-eluting stents for the treatment of de novo coronary lesions. The present investigation explored the potential of this technology to treat in-stent restenosis. METHODS AND RESULTS: Twenty-five patients with in-stent restenosis were successfully treated with the implantation of 1 or 2 sirolimus-eluting Bx VELOCITY stents in Sao Paulo, Brazil. Nine patients received 2 stents (1.4 stents per lesion). Angiographic and volumetric intravascular ultrasound (IVUS) images were obtained after the procedure and at 4 and 12 months. All vessels were patent at the time of 12-month angiography. Angiographic late loss averaged 0.07+/-0.2 mm in-stent and -0.05+/-0.3 mm in-lesion at 4 months, and 0.36+/-0.46 mm in-stent and 0.16+/-0.42 mm in-lesion after 12 months. No patient had in-stent or stent margin restenosis at 4 months, and only one patient developed in-stent restenosis at 1-year follow-up. Intimal hyperplasia by 3-dimensional IVUS was 0.92+/-1.9 mm(3) at 4 months and 2.55+/-4.9 mm(3) after 1 year. Percent volume obstruction was 0.81+/-1.7% and 1.76+/-3.4% at the 4- and 12-month follow-up, respectively. There was no evidence of stent malapposition either acutely or in the follow-up IVUS images, and there were no deaths, stent thromboses, or repeat revascularizations. CONCLUSION: This study demonstrates the safety and the potential utility of sirolimus-eluting Bx VELOCITY stents for the treatment of in-stent restenosis
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