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1.
Opt Lett ; 46(11): 2698-2701, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34061091

RESUMO

We present the experimental investigation of timing jitter and relative intensity noise of a Mamyshev ring oscillator operating in the fundamental mode-lock regime. We find that both timing jitter and intensity noise spectra are correlated to the output optical power with noise increase close to the loss of the mode-locking. In addition, we have investigated the dependence of the spectral filters wavelength separation on both timing jitter and intensity noise showing a severe degradation with filters overlapping.

2.
Opt Lett ; 45(21): 6098-6101, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33137078

RESUMO

Absolute timing jitter from a mode-locked laser is characterized with a record low noise floor of 122ys/Hz (1.5×10-14s2/Hz). We develop a novel measurement technique using cross-spectrum methods in combination with a dual balanced optical cross-correlator system, with three independent low-noise mode-locked lasers.

3.
Opt Lett ; 41(5): 898-900, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26974074

RESUMO

We report on the characterization and long-term compensation of additive timing jitter introduced by a femtosecond ytterbium regenerative amplifier with a 100 kHz repetition rate. A balanced optical cross-correlation technique is used to generate a jitter error signal. This approach is well suited to characterize the additive timing jitter of Yb amplifiers seeded by narrow spectrum Yb oscillators. The balanced optical cross-correlator is in a noncollinear configuration allowing a background free coindence detection. This setup enables the measurement of additive timing jitter from the amplifier, with a noise floor of 300 as integrated from 10 Hz to 10 kHz. The measured additive timing jitter level is about 5 fs, integrated from 0.1 Hz to 10 kHz. The amplifier timing drift characterization and control are performed for more than an hour.

4.
Mar Drugs ; 12(6): 3706-32, 2014 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-24960460

RESUMO

Cyclic imines are lipophilic marine toxins that bioaccumulate in seafood. Their structure comprises a cyclic-imino moiety, responsible for acute neurotoxicity in mice. Cyclic imines have not been linked yet to human poisonings and are not regulated in Europe, although the European Food Safety Authority requires more data to perform a conclusive risk assessment for consumers. This work presents the first detection of pinnatoxin G (PnTX-G) in Spain and 13-desmethyl spirolide C (SPX-1) in shellfish from Catalonia (Spain, NW Mediterranean Sea). Cyclic imines were found at low concentrations (2 to 60 µg/kg) in 13 samples of mussels and oysters (22 samples analyzed). Pinnatoxin G has been also detected in 17 seawater samples (out of 34) using solid phase adsorption toxin tracking devices (0.3 to 0.9 µg/kg-resin). Pinnatoxin G and SPX-1 were confirmed with both low and high resolution (<2 ppm) mass spectrometry by comparison of the response with that from reference standards. For other analogs without reference standards, we applied a strategy combining low resolution MS with a triple quadrupole mass analyzer for a fast and reliable screening, and high resolution MS LTQ Orbitrap® for unambiguous confirmation. The advantages and limitations of using high resolution MS without reference standards were discussed.


Assuntos
Alcaloides/isolamento & purificação , Cromatografia Líquida/métodos , Compostos de Espiro/isolamento & purificação , Espectrometria de Massas em Tandem/métodos , Alcaloides/análise , Animais , Bivalves/metabolismo , Iminas/análise , Iminas/isolamento & purificação , Mar Mediterrâneo , Ostreidae/metabolismo , Padrões de Referência , Reprodutibilidade dos Testes , Frutos do Mar , Espanha , Compostos de Espiro/análise
5.
Environ Monit Assess ; 185(8): 6653-66, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23275095

RESUMO

Monitoring of amnesic shellfish poisoning (ASP) toxins in shellfish from the Catalan coast started in 2001. No ASP toxins were detected in any of the analyses performed before 2008. On 22 January 2008, domoic acid (DA) was detected in Donax trunculus (0.5 mg kg(-1)) and confirmed by rapid resolution liquid chromatography-tandem mass spectrometry (0.6 mg kg(-1)). A total of 974 shellfish samples were analyzed from January 2008 to December 2011, covering all the Catalan production areas and the most important marketed species. DA was detected in 23.8 % of the samples and was recorded every month in all areas and all species, except Ostrea edulis, although the percentage of samples with DA and DA content varied widely among samples. DA exceeded the regulatory level of 20 mg kg(-1) twice: in Callista chione sampled on February 2008 and in D. trunculus sampled on April 2010. DA content in Bolinus brandaris appeared constant and close to 4.5 mg kg(-1) for months in 2009. Mytilus galloprovincialis, Crassostrea gigas, and Ruditapes sp. presented very low concentrations of DA in the Ebro Delta bays, despite 113 alert situations according to Pseudo-nitzschia spp. abundances and the high number of shellfish samples analyzed. The origin of DA in Catalan shellfish remains unknown.


Assuntos
Monitoramento Ambiental/métodos , Ácido Caínico/análogos & derivados , Frutos do Mar/análise , Poluentes Químicos da Água/análise , Animais , Contaminação de Alimentos/análise , Ácido Caínico/análise , Toxinas Marinhas/análise , Espanha
6.
Santa Clara; s.n; com; sep 17. 2005. tab.
Não convencional em Espanhol | CUMED | ID: cum-30896

RESUMO

El exudado vaginal es un método fácil y confiable para el diagnóstico de Infecciones de transmisión sexual (ITS). Puede ayudar en el diagnóstico de infecciones como Vaginosis Bacteriana, Candidiasis, Trichomoniasis y Cervicitis, sin embargo, el nivel de entrenamiento y experiencia del individuo que lo realiza es extremadamente importante para obtener buenos resultados(AU)


Assuntos
Humanos , Feminino , Exsudatos e Transudatos , Infecções Sexualmente Transmissíveis
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