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1.
Chemistry ; 25(53): 12412-12422, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31271482

RESUMO

Over the years, we developed highly selective fluorescent probes for K+ in water, which show K+ -induced fluorescence intensity enhancements, lifetime changes, or a ratiometric behavior at two emission wavelengths (cf. Scheme 1, K1-K4). In this paper, we introduce selective fluorescent probes for Na+ in water, which also show Na+ induced signal changes, which are analyzed by diverse fluorescence techniques. Initially, we synthesized the fluorescent probes 2, 4, 5, 6 and 10 for a fluorescence analysis by intensity enhancements at one wavelength by varying the Na+ responsive ionophore unit and the fluorophore moiety to adjust different Kd values for an intra- or extracellular Na+ analysis. Thus, we found that 2, 4 and 5 are Na+ selective fluorescent tools, which are able to measure physiologically important Na+ levels at wavelengths higher than 500 nm. Secondly, we developed the fluorescent probes 7 and 8 to analyze precise Na+ levels by fluorescence lifetime changes. Herein, only 8 (Kd =106 mm) is a capable fluorescent tool to measure Na+ levels in blood samples by lifetime changes. Finally, the fluorescent probe 9 was designed to show a Na+ induced ratiometric fluorescence behavior at two emission wavelengths. As desired, 9 (Kd =78 mm) showed a ratiometric fluorescence response towards Na+ ions and is a suitable tool to measure physiologically relevant Na+ levels by the intensity change of two emission wavelengths at 404 nm and 492 nm.

2.
Phys Rev Lett ; 122(8): 081104, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30932596

RESUMO

The Laser Interferometer Space Antenna (LISA) and its metrology chain have to fulfill stringent performance requirements to enable the space-based detection of gravitational waves. This implies the necessity of performance verification methods. In particular, the extraction of the interferometric phase, implemented by a phasemeter, needs to be probed for linearity and phase noise contributions. This Letter reports on a hexagonal quasimonolithic optical bench implementing a three-signal test for this purpose. Its characterization as sufficiently stable down to picometer levels is presented as well as its usage for a benchmark phasemeter performance measurement under LISA conditions. These results make it a candidate for the core of a LISA metrology verification facility.

3.
Chemistry ; 2018 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-29863303

RESUMO

This work presents two molecular fluorescent probes 1 and 2 for the selective determination of physiologically relevant K+ levels in water based on a highly K+ /Na+ selective building block, the o-(2-methoxyethoxy)phenylaza-18-crown-6 lariat ether unit. Fluorescent probe 1 showed a high K+ -induced fluorescence enhancement (FE) by a factor of 7.7 of the anthracenic emission and a dissociation constant (Kd ) value of 38 mm in water. Further, for 2+K+ , we observed a dual emission behavior at 405 and 505 nm. K+ increases the fluorescence intensity of 2 at 405 nm by a factor of approximately 4.6 and K+ decreases the fluorescence intensity at 505 nm by a factor of about 4.8. Fluorescent probe 2+K+ exhibited a Kd value of approximately 8 mm in Na+ -free solutions and in combined K+ /Na+ solution a similar Kd value of about 9 mm was found, reflecting the high K+ /Na+ selectivity of 2 in water. Therefore, 2 is a promising fluorescent tool to measure ratiometrically and selectively physiologically relevant K+ levels.

4.
Issues Ment Health Nurs ; 38(11): 907-914, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28933576

RESUMO

In mental health nursing, recovery-orientation is regarded as a best practice approach for patient care. To assess the effect of an intervention utilising a recovery-oriented approach in acute practice, a controlled pilot trial was conducted. On intervention wards, mental health nurses received special training. Recovery Self-Assessment Scale was used to assess the effects of the training. No statistically significant effects were found, between the experimental conditions. Reasons for this result may be methodological, practical or due an intervention that was not powerful enough. Recovery-oriented intervention studies in mental health nursing should be conducted with caution.


Assuntos
Atitude do Pessoal de Saúde , Transtornos Mentais/enfermagem , Unidade Hospitalar de Psiquiatria , Enfermagem Psiquiátrica/educação , Adulto , Feminino , Objetivos , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Recuperação de Função Fisiológica
5.
Chemistry ; 23(68): 17186-17190, 2017 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-28895214

RESUMO

The new K+ -selective fluorescent probes 1 and 2 were obtained by CuI -catalyzed 1,3-dipolar azide alkyne cycloaddition (CuAAC) reactions of an alkyne-substituted [1,3]dioxolo[4,5-f][1,3]benzodioxole (DBD) ester fluorophore with azido-functionalized N-phenylaza-18-crown-6 ether and N-(o-isopropoxy) phenylaza-18-crown-6 ether, respectively. Probes 1 and 2 allow the detection of K+ in the presence of Na+ in water by fluorescence enhancement (2.2 for 1 at 2000 mm K+ and 2.5 for 2 at 160 mm K+ ). Fluorescence lifetime measurements in the absence and presence of K+ revealed bi-exponential decay kinetics with similar lifetimes, however with different proportions changing the averaged fluorescence decay times (τf(av) ). For 1 a decrease of τf(av) from 12.4 to 9.3 ns and for 2 an increase from 17.8 to 21.8 ns was observed. Variation of the substituent in ortho position of the aniline unit of the N-phenylaza-18-crown-6 host permits the modulation of the Kd value for a certain K+ concentration. For example, substitution of H in 1 by the isopropoxy group (2) decreased the Kd value from >300 mm to 10 mm. 2 was chosen for studying the efflux of K+ from human red blood cells (RBC). Upon addition of the Ca2+ ionophor ionomycin to a RBC suspension in a buffer containing Ca2+ , the fluorescence of 2 slightly rose within 10 min, however, after 120 min a significant increase was observed.


Assuntos
Corantes Fluorescentes/química , Potássio/química , Cálcio/química , Catálise , Células Cultivadas , Cobre , Éteres de Coroa/química , Reação de Cicloadição , Eritrócitos/química , Eritrócitos/citologia , Eritrócitos/metabolismo , Corantes Fluorescentes/síntese química , Humanos , Ionomicina/química , Íons/química , Cinética , Espectrometria de Fluorescência
6.
Opt Express ; 25(7): 7999-8010, 2017 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-28380922

RESUMO

A photoreceiver (PR) is required for the opto-electrical conversion of signals in intersatellite laser interferometers. Noise sources that originate or couple in the PR reduce the system carrier-to-noise-density, which is often represented by its phase noise density. In this work, we analyze the common noise sources in a PR used for space-based interferometry. Additionally, we present the results from the characterization of the PRs in GRACE-FO, a mission which will pioneer intersatellite laser interferometry. The estimated phase noise is shot-noise limited at 10-4 rad/Hz1/2 down to 10-2 Hz, almost 4 orders of magnitude below the instrument top level requirement (0.5 rad/Hz1/2). Below 10-2 Hz, the PR finite phase response noise dominates but the levels still comply with the instrument requirement. The sub-mHz noise levels and the PR electronic noise have been identified as key design factors for the LISA PR.

7.
Chemistry ; 23(30): 7255-7263, 2017 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-28195410

RESUMO

There is a tremendous demand for highly Na+ -selective fluoroionophores to monitor the top analyte Na+ in life science. Here, we report a systematic route to develop highly Na+ /K+ selective fluorescent probes. Thus, we synthesized a set of fluoroionophores 1, 3, 4, 5, 8 and 9 (see Scheme ) to investigate the Na+ /K+ selectivity and Na+ - complex stability in CH3 CN and H2 O. These Na+ -probes bear different 15-crown-5 moieties to bind Na+ stronger than K+ . In the set of the diethylaminocoumarin-substituted fluoroionophores 1-5, the following trend of fluorescence quenching 1>3>2>4>5 in CH3 CN was observed. Therefore, the flexibility of the aza-15-crown-5 moieties in 1-4 determines the conjugation of the nitrogen lone pair with the aromatic ring. As a consequence, 1 showed in CH3 CN the highest Na+ -induced fluorescence enhancement (FE) by a factor of 46.5 and a weaker K+ induced FE of 3.7. The Na+ -complex stability of 1-4 in CH3 CN is enhanced in the following order of 2>4>3>1, assuming that the O-atom of the methoxy group in the ortho-position, as shown in 2, strengthened the Na+ -complex formation. Furthermore, we found for the N-(o-methoxyphenyl)aza-15-crown-5 substituted fluoroionophores 2, 8 and 9 in H2 O, an enhanced Na+ -complex stability in the following order 8>2>9 and an increased Na+ /K+ selectivity in the reverse order 9>2>8. Notably, the Na+ -induced FE of 8 (FEF=10.9), 2 (FEF=5.0) and 9 (FEF=2.0) showed a similar trend associated with a decreased K+ -induced FE [8 (FEF=2.7)>2 (FEF=1.5)>9 (FEF=1.1)]. Here, the Na+ -complex stability and Na+ /K+ selectivity is also influenced by the fluorophore moiety. Thus, fluorescent probe 8 (Kd =48 mm) allows high-contrast, sensitive, and selective Na+ measurements over extracellular K+ levels. A higher Na+ /K+ selectivity showed fluorescent probe 9, but also a higher Kd value of 223 mm. Therefore, 9 is a suitable tool to measure Na+ concentrations up to 300 mm at a fluorescence emission of 614 nm.

8.
Opt Express ; 24(2): 1676-84, 2016 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-26832546

RESUMO

Experiments for space and ground-based gravitational wave detectors often require a large dynamic range interferometric position readout of test masses with 1 pm/√Hz precision over long time scales. Heterodyne interferometer schemes that achieve such precisions are available, but they require complex optical set-ups, limiting their scalability for multiple channels. This article presents the first experimental results on deep frequency modulation interferometry, a new technique that combines sinusoidal laser frequency modulation in unequal arm length interferometers with a non-linear fit algorithm. We have tested the technique in a Michelson and a Mach-Zehnder Interferometer topology, respectively, demonstrated continuous phase tracking of a moving mirror and achieved a performance equivalent to a displacement sensitivity of 250 pm/Hz at 1 mHz between the phase measurements of two photodetectors monitoring the same optical signal. By performing time series fitting of the extracted interference signals, we measured that the linearity of the laser frequency modulation is on the order of 2% for the laser source used.

9.
Chem Asian J ; 11(2): 241-7, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26473334

RESUMO

A desirable goal is to synthesize easily accessible and highly K(+) /Na(+) -selective fluoroionophores to monitor physiological K(+) levels in vitro and in vivo. Therefore, highly K(+) /Na(+) -selective ionophores have to be developed. Herein, we obtained in a sequence of only four synthetic steps a set of K(+) -responsive fluorescent probes 4, 5 and 6. In a systematic study, we investigated the influence of the alkoxy substitution in ortho position of the aniline moiety in π-conjugated aniline-1,2,3-triazole-coumarin-fluoroionophores 4, 5 and 6 [R=MeO (4), EtO (5) and iPrO (6)] towards the K(+) -complex stability and K(+) /Na(+) selectivity. The highest K(+) -complex stability showed fluoroionophore 4 with a dissociation constant Kd of 19 mm, but the Kd value increases to 31 mm in combined K(+) /Na(+) solutions, indicating a poor K(+) /Na(+) selectivity. By contrast, 6 showed even in the presence of competitive Na(+) ions equal Kd values (Kd (K+) =45 mm and Kd (K+/Na+) =45 mm) and equal K(+) -induced fluorescence enhancement factors (FEFs=2.3). Thus, the fluorescent probe 6 showed an outstanding K(+) /Na(+) selectivity and is a suitable fluorescent tool to measure physiological K(+) levels in the range of 10-80 mm in vitro. Further, the isopropoxy-substituted N-phenylaza[18]crown-6 ionophore in 6 is a highly K(+) -selective building block with a feasible synthetic route.

12.
Rev Sci Instrum ; 86(7): 074501, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26233398

RESUMO

Precision phase readout of optical beat note signals is one of the core techniques required for intersatellite laser interferometry. Future space based gravitational wave detectors like eLISA require such a readout over a wide range of MHz frequencies, due to orbit induced Doppler shifts, with a precision in the order of µrad/√Hz at frequencies between 0.1 mHz and 1 Hz. In this paper, we present phase readout systems, so-called phasemeters, that are able to achieve such precisions and we discuss various means that have been employed to reduce noise in the analogue circuit domain and during digitisation. We also discuss the influence of some non-linear noise sources in the analogue domain of such phasemeters. And finally, we present the performance that was achieved during testing of the elegant breadboard model of the LISA phasemeter, which was developed in the scope of a European Space Agency technology development activity.

13.
Chemistry ; 21(32): 11306-10, 2015 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-26178764

RESUMO

A highly K(+)-selective two-photon fluorescent probe for the in vitro monitoring of physiological K(+) levels in the range of 1-100 mM is reported. The two-photon excited fluorescence (TPEF) probe shows a fluorescence enhancement (FE) by a factor of about three in the presence of 160 mM K(+), independently of one-photon (OP, 430 nm) or two-photon (TP, 860 nm) excitation and comparable K(+)-induced FEs in the presence of competitive Na(+) ions. The estimated dissociation constant (Kd ) values in Na(+)-free solutions (Kd (OP) =(28±5) mM and Kd (TP)=(36±6) mM) and in combined K(+)/Na(+) solutions (Kd (OP) =(38±8) mM and Kd (TP)=(46±25) mM) reflecting the high K(+)/Na(+) selectivity of the fluorescent probe. The TP absorption cross-section (σ2PA ) of the TPEF probe+160 mM K(+) is 26 GM at 860 nm. Therefore, the TPEF probe is a suitable tool for the in vitro determination of K(+).

15.
Chem Commun (Camb) ; 50(91): 14167-70, 2014 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-25277847

RESUMO

We report a 1,2,3-triazol fluoroionophore for detecting Na(+) that shows in vitro enhancement in the Na(+)-induced fluorescence intensity and decay time. The Na(+)-selective molecule 1 was incorporated into a hydrogel as a part of a fiber optical sensor. This sensor allows the direct determination of Na(+) in the range of 1-10 mM by measuring reversible fluorescence decay time changes.


Assuntos
Fluorescência , Sódio/análise , Triazóis/química , Estrutura Molecular
16.
Opt Express ; 22(15): 18214-23, 2014 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-25089440

RESUMO

We present the development of an advanced phasemeter for the deep phase modulation interferometry technique. This technique aims for precise length measurements with a high dynamic range using little optical hardware. The advanced phasemeter uses fast ADCs and an FPGA to implement a design of multiple single-bin Fourier transforms running at high sampling rates. Non-linear noise sources in the design were analyzed and suppressed. A null measurement with an optical beatnote signal using λ = 1064nm was conducted. It showed a sensitivity of 0.8µrad/√Hz below 10Hz and 13.3µrad/√Hz above, with a large dynamic range. The shown performance could enable the measuring of optical path lengths with sensitivities down to 0.14pm/√Hz and 2.3pm/√Hz, respectively, over several fringes in an interferometric setup.

18.
Chemistry ; 19(44): 14911-7, 2013 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-24105686

RESUMO

Herein, we report the synthesis of two phenylaza-[18]crown-6 lariat ethers with a coumarin fluorophore (1 and 2) and we reveal that compound 1 is an excellent probe for K(+) ions under simulated physiological conditions. The presence of a 2-methoxyethoxy lariat group at the ortho position of the anilino moiety is crucial to the substantially increased stability of compounds 1 and 2 over their lariat-free phenylaza-[18]crown-6 ether analogues. Probe 1 shows a high K(+)/Na(+) selectivity and a 2.5-fold fluorescence enhancement was observed in the presence of 100 mM K(+) ions. A fluorescent membrane sensor, which was prepared by incorporating probe 1 into a hydrogel, showed a fully reversible response, a response time of 150 s, and a signal change of 7.8% per 1 mM K(+) within the range 1-10 mM K(+). The membrane was easily fabricated (only a single sensing layer on a solid polyester support), yet no leaching was observed. Moreover, compound 1 rapidly permeated into cells, was cytocompatible, and was suitable for the fluorescent imaging of K(+) ions on both the extracellular and intracellular levels.


Assuntos
Éteres de Coroa/química , Géis/química , Ionóforos/química , Íons/química , Potássio/química , Fluorescência , Estrutura Molecular , Espectrometria de Fluorescência
20.
Chemistry ; 18(34): 10506-10, 2012 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-22807148

RESUMO

Copper chemodosimeters: The copper(II)-promoted air oxidation of 1-3 to form 4-6 permits the highly selective colorimetric detection of Cu(2+) ions. The formation of copper(II) complexes of 4-6 proceeds rapidly, and the chemodosimeters 1-3 are viable at physiological pH.


Assuntos
Cobre/análise , Nitrilos/síntese química , Piridinas/síntese química , Colorimetria , Cobre/química , Concentração de Íons de Hidrogênio , Nitrilos/química , Oxirredução , Piridinas/química , Espectrofotometria Ultravioleta/métodos
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