Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Biomarkers ; : 1-6, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38588595

RESUMO

BACKGROUND: Currently available risk scores fail to accurately predict morbidity and mortality in patients with severe symptomatic aortic stenosis who undergo transcatheter aortic valve implantation (TAVI). In this context, biomarkers like matrix metalloproteinase-2 (MMP-2) and Galectin-3 (Gal-3) may provide additional prognostic information. METHODS: Patients with severe aortic stenosis undergoing consecutive, elective, transfemoral TAVI were included. Baseline demographic data, functional status, echocardiographic findings, clinical outcomes and biomarker levels were collected and analysed. RESULTS: The study cohort consisted of 89 patients (age 80.4 ± 5.1 years, EuroScore II 7.1 ± 5.8%). During a median follow-up period of 526 d, 28 patients (31.4%) died. Among those who died, median baseline MMP-2 (alive: 221.6 [170.4; 263] pg/mL vs. deceased: 272.1 [225; 308.8] pg/mL, p < 0.001) and Gal-3 levels (alive: 19.1 [13.5; 24.6] pg/mL vs. deceased: 25 [17.6; 29.5] pg/mL, p = 0.006) were higher than in survivors. In ROC analysis, MMP-2 reached an acceptable level of discrimination to predict mortality (AUC 0.733, 95% CI [0.62; 0.83], p < 0.001), but the predictive value of Gal-3 was poor (AUC 0.677, 95% CI [0.56; 0.79], p = 0.002). Kaplan-Meier and Cox regression analyses showed that patients with MMP-2 and Gal-3 concentrations above the median at baseline had significantly impaired long-term survival (p = 0.004 and p = 0.02, respectively). CONCLUSIONS: In patients with severe aortic stenosis undergoing transfemoral TAVI, MMP-2 and to a lesser extent Gal-3, seem to have additive value in optimizing risk prediction and streamlining decision-making.

2.
JACC Case Rep ; 11: 101789, 2023 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-37077447

RESUMO

We report a complex case of a 53-year-old male patient with recurrent ischemic ventricular septal defect that had been occluded by a surgical patch. Treatment was accomplished utilizing a 3-dimensional-printed model for preprocedural planning. In the future, printing of 3-dimensional models could offer new therapeutic strategies on an individual level. (Level of Difficulty: Intermediate.).

3.
Eur Heart J Case Rep ; 7(3): ytad089, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36937235

RESUMO

Background: Robotically assisted remote-controlled PCI (rPCI) was introduced in the past decade as one of the latest enhancements in this rapidly evolving field. The use of a second-generation rPCI system in ST-elevation myocardial infarction (STEMI) is an effort to couple immediate revascularization with the accuracy of newer robotic assistance and software support. Case summary: Here we report on the safety and efficacy of rPCI applied to a 74-year-old female STEMI patient with persistent acute chest pain as well as regional wall motion abnormalities in the echocardiogram. The first medical contact-to-device time was 76 min, and door-to-balloon time was 33 min. The impatient course was uneventful, so the patient was discharged from hospital after 5 days. To the best of our knowledge, this is the first report of the successful application of second-generation rPCI in STEMI. Discussion: In the case presented, rPCI was feasible and safe even in acute coronary syndrome based on a single-centre experience. rPCI is a revolutionary new technique that may be applied to various types of clinical presentations.

4.
Eur Heart J Case Rep ; 7(1): ytac427, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36694869

RESUMO

Background: Percutaneous coronary intervention (PCI) is the standard-of-care treatment for left main stenosis as an alternative to bypass surgery. In addition, severe coronary lesion calcification can be modified by intravascular lithotripsy (IVL). However, with PCI and debulking treatment options, there are inherent limitations. PCI poses an increased health burden for the treating physician that is associated with wearing a heavy, lead-lined apron and being exposed to radiation. To overcome these issues, a robotically assisted angioplasty system (rPCI) was established that enables the operator to perform PCI remotely in routine clinical procedures. Furthermore, IVL have not been used remotely. Case summary: Here, we report the use of this technique for treating a heavily calcified left main stenosis in an 82-year-old male with previously diagnosed two-vessel coronary artery disease, progressive symptoms of dyspnoea at high cardio-vascular risk profile. The decision of the local heart team declined surgery. To the best of our knowledge, this is the first report of successful rPCI combined with IVL. Discussion: In the case presented, rPCI was feasible and safe even in a complex lesion of the left main coronary artery requiring IVL. rPCI is a revolutionary new technique that may be applied to various types of coronary artery lesions.

5.
Catheter Cardiovasc Interv ; 99(3): 533-540, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34463427

RESUMO

OBJECTIVES: To asses mid-term clinical outcomes of bioresorbable vascular scaffolds (BVS) for the treatment of coronary artery disease in a large-scale all-comers population. BACKGROUND: Several clinical settings are underrepresented in randomized studies investigating BVS against drug-eluting stents. Whether their results can be translated into the heterogeny patient population seen during daily routine requires further investigation. METHODS: The European ABSORB Consortium comprises the following European registries: GABI-R, ABSORB UK Registry, ABSORB France, BVS RAI Registry, and REPARA BVS Registry, which all prospectively collected patient-level data regarding outcomes following unrestricted BVS implantation. The primary endpoint of target lesion failure (TLF) includes cardiac death, target-vessel myocardial infarction (TVMI) and target-lesion revascularisation (TLR) at 12 months. The incidence of scaffold thrombosis (ST) according to ARC criteria was also assessed. Multivariable analysis was used to adjust for differences in patient and lesion characteristics. RESULTS: A total of 10,312 patients (mean age 58.4 ± 11.4 y) underwent BVS implantation during routine practice. The 12-month follow-up was complete in 95.5% of patients. At 12 months, the primary endpoint of TLF occurred in 3.6%; its components cardiac death, TVMI and TLR were documented in 1.2%, 1.8%, and 2.6%, respectively. The definite/probable ST rate was 1.7%. Absence of predilatation, discontinuation of DAPT and scaffold diameter below 3 mm were independent predictors of ST. CONCLUSIONS: The EAC demonstrates reasonable real-world clinical outcome data after BVS implantation. However, the rate of scaffold thrombosis remains high.


Assuntos
Doença da Artéria Coronariana , Stents Farmacológicos , Intervenção Coronária Percutânea , Implantes Absorvíveis , Idoso , Doença da Artéria Coronariana/induzido quimicamente , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/terapia , Everolimo/efeitos adversos , Humanos , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/efeitos adversos , Desenho de Prótese , Tecidos Suporte , Resultado do Tratamento
6.
Surg Technol Int ; 38: 325-330, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-34081770

RESUMO

Interventional cardiovascular medicine has seen constant progress over the last few decades. Since the first angiograms and percutaneous transluminal coronary angioplasty were carried out, this progress has been tremendous and has led to a substantial decline in cardiovascular morbidity and mortality. The purpose of this article is to report and review the latest developments and evidence in robotics-assisted percutaneous coronary intervention (rPCI) and its potential future applications, opportunities, and limitations. Contemporary evidence shows that rPCI can lead to a significant reduction in radiation exposure as well as medical hazards for cardiologists. Rates of device and procedural success remain high and there is no evidence of a disadvantage for the patient. The accuracy of implantation with a reduced geographic mismatch is a further advantage that can result in a higher quality of treatment. Even in complex coronary lesions and procedures, rPCI seems to be safe and efficient. The latest developments include telestenting over hundreds of kilometers from a remote platform. Currently, the main limitations are the absence of large-scale randomized trials for the valid assessment of the benefits and disadvantages of rPCI as well as the technical limitations of the currently available rPCI systems. rPCI is a forward-looking innovation in cardiology that is applicable to a wide range of coronary interventions. Despite the present lack of knowledge and the limited data concerning the outcome for the patient, the available literature reveals promising results that should lead to improvements for physicians and patients.


Assuntos
Angioplastia Coronária com Balão , Doença da Artéria Coronariana , Intervenção Coronária Percutânea , Robótica , Doença da Artéria Coronariana/cirurgia , Humanos , Stents
7.
Nat Commun ; 12(1): 1327, 2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33637741

RESUMO

The particle-like nature of light becomes evident in the photon statistics of fluorescence from single quantum systems as photon antibunching. In multichromophoric systems, exciton diffusion and subsequent annihilation occurs. These processes also yield photon antibunching but cannot be interpreted reliably. Here we develop picosecond time-resolved antibunching to identify and decode such processes. We use this method to measure the true number of chromophores on well-defined multichromophoric DNA-origami structures, and precisely determine the distance-dependent rates of annihilation between excitons. Further, this allows us to measure exciton diffusion in mesoscopic H- and J-type conjugated-polymer aggregates. We distinguish between one-dimensional intra-chain and three-dimensional inter-chain exciton diffusion at different times after excitation and determine the disorder-dependent diffusion lengths. Our method provides a powerful lens through which excitons can be studied at the single-particle level, enabling the rational design of improved excitonic probes such as ultra-bright fluorescent nanoparticles and materials for optoelectronic devices.

8.
Small ; 17(5): e2006425, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33448114

RESUMO

Break junctions in noble-metal films can exhibit electroluminescence (EL) through inelastic electron tunneling. The EL spectrum can be tuned by depositing a single-layer crystal of a transition-metal dichalcogenide (TMDC) on top. Whereas the emission from the gaps between silver or gold nanoparticles formed in the break junction is spectrally broad, the hybrid metal/TMDC structure shows distinct luminescence from the TMDC material. The EL from individual hotspots is found to be linearly polarized, with a polarization axis apparently oriented randomly. Surprisingly, the degree of polarization is retained in the EL from the TMDC monolayer at room temperature. In analogy to polarized photoluminescence experiments, such polarized EL can be interpreted as a signature of valley-selective transitions, suggesting that spin-flip transitions and dephasing for excitons in the K valleys are of limited importance. However, polarized EL may also originate from the metal nanoparticles formed under electromigration which constitute optical antenna structures. Such antennae can apparently change over time since jumps in the polarization are observed in bare silver-nanoparticle films. Remarkably, photon-correlation spectroscopy reveals that gold-nanoparticle films exhibit signatures of deterministic single-photon emission in the EL, suggesting a route to designing room-temperature polarized single-photon sources with tunable photon energy through the choice of TMDC overlayer.

9.
Catheter Cardiovasc Interv ; 97(1): 56-62, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32187817

RESUMO

OBJECTIVES: The aim of this study was to evaluate very long-term results after unrestricted everolimus-eluting bioresorbable scaffolds (BRS) implantation. BACKGROUND: Previous randomized studies mainly included selected patients differing from those seen during daily routine and long-term data from all-comers registries are sparse. METHODS: Consecutive patients undergoing BRS implantation were included in this observational, single center study. Clinical follow-up was conducted up to 5 years. Endpoint of interest was the composite of target lesion failure (TLF), including target-vessel myocardial infarction and target lesion revascularization and cardiac death. Furthermore, ARC-defined scaffold thrombosis (ScT) were assessed. RESULTS: A total of 176 patients with a median age of 64 (55 - 72) years were analyzed, of which 59.6% presented an acute coronary syndrome. A total of 183 mainly complex lesions (55.8%) were treated. At 5 years, the rate for TLF was 21.6%. Definite or probable ScT rate was 4.1%. The rate of ScT within the first year was 2.8% and afterwards 1.2%. Notably, no ScT was seen later than 2 years. CONCLUSIONS: Although this real-world registry displays high rates of clinical events during long-term follow-up, no ScT was seen after 2 years.


Assuntos
Doença da Artéria Coronariana , Stents Farmacológicos , Intervenção Coronária Percutânea , Implantes Absorvíveis , Idoso , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/cirurgia , Everolimo/efeitos adversos , Seguimentos , Humanos , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/efeitos adversos , Desenho de Prótese , Resultado do Tratamento
10.
Int J Cardiol ; 312: 42-47, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32151443

RESUMO

BACKGROUND: Bioresorbable scaffolds (BRS) have been shown to be inferior to drug-eluting stents in randomized trials. Nevertheless, patients treated during daily routine differ from those treated within randomized trials and thus need further long-term evaluation. The present investigation aims to address this lack. METHODS: Consecutive patients with coronary artery disease treated with implantation of everolimus-eluting BRS at 5 centers in Germany were included. Clinical follow-up was assessed up to 3 years. Analysis of clinical outcomes was performed by pooling of the individual patient data sets of each center. The major clinical endpoints of interest was target lesion failure (TLF) a composite of cardiac death, target vessel myocardial infarction and target lesion revascularization. Furthermore occurrence of definite scaffold thrombosis was evaluated. A multivariable Cox regression analysis was applied to identify independent predictors of TLF. RESULTS: A total of 1614 patients treated with BRS were analyzed (mean age 64.0 ± 10.9 years, 75.8% male, 28.3% diabetics). A total 1817 lesions were treated with BRS and 56.0% were considered to be complex. At 3 years, the rate of TLF was 17.1% and definite scaffold thrombosis was noted in 2.6%. Independent predictors of TLF were a higher age, diabetes, bifurcation, complex lesions and the use of small BRS. CONCLUSIONS: In this large-scale analysis of patients undergoing BRS implantation in daily routine, event rates were high, but in line with randomized studies. Predictors of TLF were identified which may optimize patient and lesion selection for BRS.


Assuntos
Doença da Artéria Coronariana , Intervenção Coronária Percutânea , Implantes Absorvíveis , Idoso , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/cirurgia , Everolimo , Feminino , Seguimentos , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/efeitos adversos , Desenho de Prótese , Resultado do Tratamento
11.
Nano Lett ; 19(12): 8896-8902, 2019 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-31646869

RESUMO

Single formamidinium lead bromide (FAPbBr3) perovskite nanocubes, approximately 10 nm in size, have extinction cross sections orders of magnitude larger than single dye molecules and can therefore be used to photoexcite one single dye molecule within their immediate vicinity by means of excitation-energy transfer (EET). The rate of photon emission by the single dye molecule is increased by 2 orders of magnitude under excitation by EET compared to direct excitation at the same laser fluence. Because the dye cannot accommodate biexcitons, NC biexcitons are filtered out by EET, giving rise to up to an order-of-magnitude improvement in the fidelity of photon antibunching. We demonstrate here that, contrary to expectation, energy transfer from the nanocrystal to dye molecules does not depend on the spectral line widths of the donor and acceptor and is therefore not governed by Förster's theory of resonance energy transfer (FRET). Two different cyanine dye acceptors with substantially different spectral overlaps with the nanocrystal donor show a similar light-harvesting capability. Cooling the sample from room temperature to 5 K reduces the average transition line widths 25-fold but has no apparent effect on the number of molecules emitting, i.e., on the spatial density of single dye molecules being photoexcited by single nanocrystals. Narrow zero-phonon lines are identified for both donor and acceptor, with an energetic separation of over 40 times the line width, implying a complete absence of spectral overlap-even though EET is evident. Both donor and acceptor exhibit spectral fluctuations, but no correlation is apparent between the jitter, which controls spectral overlap, and the overall light harvesting. We conclude that the energy transfer process is fundamentally nonresonant, implying effective energy dissipation in the perovskite donor because of strong electron-phonon coupling of the carriers comprising the exciton. The work highlights the importance of performing cryogenic spectroscopy to reveal the underlying mechanisms of energy transfer in complex donor-acceptor systems.

12.
J Phys Chem Lett ; 10(5): 1055-1062, 2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30789278

RESUMO

The extraordinary absorption cross section and high photoluminescence (PL) quantum yield of perovskite nanocrystals make this type of material attractive to a variety of applications in optoelectronics. For the same reasons, nanocrystals are also ideally suited to function as nanoantennae to excite nearby single dye molecules by fluorescence resonance energy transfer (FRET). Here, we demonstrate that FAPbBr3 perovskite nanocrystals, of cuboidal shape and approximately 10 nm in size, are capable of selectively exciting single cyanine 3 molecules at a concentration 100-fold higher than standard single-molecule concentrations. This FRET antenna mechanism increases the effective brightness of the single dye molecules 100-fold. Photon statistics and emission polarization measurements provide evidence for the FRET process by revealing photon antibunching with unprecedented fidelity and highly polarized emission stemming from single dye molecules. Remarkably, the quality of single-photon emission improves 1.5-fold compared to emission collected directly from the nanocrystals because the higher excited states of the dye molecule act as effective filters to multiexcitons. The same process gives rise to efficient deshelving of the molecular triplet state by reverse intersystem crossing (RISC), translating into a reduction of the PL saturation of the dye, thereby increasing the maximum achievable PL intensity of the dye by a factor of 3.

13.
Nat Nanotechnol ; 12(7): 637-641, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28396606

RESUMO

Few inventions have shaped the world like the incandescent bulb. Edison used thermal radiation from ohmically heated conductors, but some noble metals also exhibit 'cold' electroluminescence in percolation films, tunnel diodes, electromigrated nanoparticle aggregates, optical antennas or scanning tunnelling microscopy. The origin of this radiation, which is spectrally broad and depends on applied bias, is controversial given the low radiative yields of electronic transitions. Nanoparticle electroluminescence is particularly intriguing because it involves localized surface-plasmon resonances with large dipole moments. Such plasmons enable very efficient non-radiative fluorescence resonance energy transfer (FRET) coupling to proximal resonant dipole transitions. Here, we demonstrate nanoscopic FRET-light-emitting diodes which exploit the opposite process, energy transfer from silver nanoparticles to exfoliated monolayers of transition-metal dichalcogenides. In diffraction-limited hotspots showing pronounced photon bunching, broadband silver electroluminescence is focused into the narrow excitonic resonance of the atomically thin overlayer. Such devices may offer alternatives to conventional nano-light-emitting diodes in on-chip optical interconnects.

14.
BMJ Open ; 6(11): e014288, 2016 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-27821601

RESUMO

INTRODUCTION: Smoking is the largest cause of preventable death globally. Most smokers smoke their first cigarette in early adolescence. We took advantage of the widespread availability of mobile phones and adolescents' interest in appearance to develop a free photoaging app which is promoted via a poster campaign in secondary schools. This study aims to evaluate its effectiveness regarding smoking prevalence and students' attitudes towards smoking. METHODS AND ANALYSIS: A randomised controlled trial is conducted with 9851 students of both genders with an average age of 12 years in grades 6 and 7 of 126 secondary schools in Germany. At present, cigarette smoking prevalence in our sample is 4.7%, with 4.6% of the students currently using e-cigarettes (1.6% use both). The prospective experimental study design includes measurements at baseline and at 6, 12 and 24 months postintervention via a questionnaire plus a random cotinine saliva sample at 24 months postintervention. The study groups consist of randomised schools receiving the Smokerface poster campaign and control schools with comparable baseline data (no intervention). The primary end point is the difference of change in smoking prevalence in the intervention group versus the difference in the control group at 24 months follow-up. Longitudinal changes in smoking-related attitudes, the number of new smokers and quitters and the change in the number of never-smokers will be compared between the two groups as secondary outcomes. ETHICS AND DISSEMINATION: Ethical approval was obtained from the ethics committee of the University of Gießen and the ministries of cultural affairs, both in Germany. Results will be disseminated at conferences, in peer-reviewed journals, on our websites and throughout the multinational Education Against Tobacco network. TRIAL REGISTRATION NUMBER: NCT02544360, Pre-results.


Assuntos
Envelhecimento/efeitos dos fármacos , Pôsteres como Assunto , Serviços de Saúde Escolar , Smartphone , Abandono do Hábito de Fumar/métodos , Fumar/epidemiologia , Software , Adolescente , Criança , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Prevalência , Estudos Prospectivos
15.
J Phys Chem Lett ; 7(22): 4451-4457, 2016 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-27786495

RESUMO

The microscopic orientation and position of photoactive molecules is crucial to the operation of optoelectronic devices such as OLEDs and solar cells. Here, we introduce a shape-persistent macrocyclic molecule as an excellent fluorescent probe to simply measure (i) its orientation by rotating the excitation polarization and recording the strength of modulation in photoluminescence (PL) and (ii) its position in a film by analyzing the overall PL brightness at the molecular level. The unique shape, the absorption and the fluorescence properties of this probe yield information on molecular orientation and position. We control orientation and positioning of the probe in a polymer film by solvent vapor annealing (SVA). During the SVA process the molecules accumulate at the polymer/air interface, where they adopt a flat orientation, much like water lilies on the surface of a pond. The results are potentially significant for OLED fabrication and single-molecule spectroscopy (SMS) in general.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...