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1.
Methods Appl Fluoresc ; 12(3)2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38834089

RESUMEN

This technical note presents a device to diminish scattering signal in front-face fluorescence spectra while obtaining fluorescence signal. The beam path in a commercial fluorescence spectrometer was modified by two deflecting mirrors, leading reflections away from the sensor. This light path modifying (LPM) device was tested with two fluid and three solid substances, where the scattering-to-fluorescence ratio improved by a factor of 1.7 to 7.6. The spectra obtained with the LPM were much clearer, and distortion of the fluorescence peaks was avoided. Scans of quinine sulphate complied well with reference spectra.

2.
Mechanobiol Med ; 2(1)2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38721590

RESUMEN

Accumulating evidence strongly suggests that cell chirality plays a pivotal role in driving left-right (LR) symmetry breaking, a widespread phenomenon in living organisms. Whole embryos and excised organs have historically been employed to investigate LR symmetry breaking and have yielded exciting findings. In recent years, in vitro engineered platforms have emerged as powerful tools to reveal cellular chiral biases and led to uncovering molecular and biophysical insights into chiral morphogenesis, including the significant role of the actin cytoskeleton. Establishing a link between observed in vivo tissue chiral morphogenesis and the determined chiral bias of cells in vitro has become increasingly important. In this regard, computational mathematical models hold immense value as they can explain and predict tissue morphogenic behavior based on the chiral biases of individual cells. Here, we present the formulations and discoveries achieved using various computational models spanning different biological scales, from the molecular and cellular levels to tissue and organ levels. Furthermore, we offer insights into future directions and the role of such models in advancing the study of asymmetric cellular mechanobiology.

3.
J Anal Toxicol ; 48(5): 393-397, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38502107

RESUMEN

An unidentified compound in putrefied postmortem blood samples showed identical accurate mass and chromatographic behavior as 3,4-methylenedioxyamphetamine (MDA) and led to false-positive preliminary screening results. The aim of the study was to identify this unknown interference. Postmortem blood samples were analyzed after protein precipitation on a QExactive Focus high-resolution mass spectrometer (Thermo Fisher, Germany) coupled to a RP C18 column (Macherey-Nagel, Germany). Based on the analysis of mass spectrometry (MS) adducts and isotope ratios using fullscan (m/z 134-330) information, the empiric formula of the protonated molecule [M + H]+ of the unknown compound was found to be C10H14O2N (+ 0.6 ppm). Product ion spectra recorded using normalized collision energy 22% showed a base peak of C8H9O1 (+ 1.5 ppm) and a low-abundant water loss to C7H9 (+ 1.9 ppm), neutral losses of C2H2O and NH3 were found. Based on fullscan and MS-MS information and under consideration of the observed order of neutral losses, the compound was presumptively identified as N-acetyltyramine. This assumption was supported by SIRIUS software showing a SIRIUS score of 99.43% for N-acetyltyramine. Finally, the putative structure annotation was confirmed by a reference compound. The described false-positive MDA findings could be attributed to the presence of N-acetyltyramine in putrefied blood samples. Being an isomer of MDA, N-acetyltyramine could not be distinguished by high-resolution data of the protonated molecules. The presented results once again highlight that false-positive findings may occur even in hyphenated high-resolution mass spectrometry (HRMS) when using full-scan information only.


Asunto(s)
Detección de Abuso de Sustancias , Humanos , Reacciones Falso Positivas , Detección de Abuso de Sustancias/métodos , Toxicología Forense/métodos , Tiramina/sangre , Espectrometría de Masas en Tándem , Espectrometría de Masas , Autopsia , N-Metil-3,4-metilenodioxianfetamina/sangre
4.
Artículo en Inglés | MEDLINE | ID: mdl-38330519

RESUMEN

Pentaerythrityl tetranitrate (PETN) is an established drug in the treatment of coronary heart disease and heart failure. It is assumed, that the vasodilative and vasoprotective effects of PETN also have a positive impact on pregnant patients with impaired placental perfusion and studies evaluating the effect of PETN in risk pregnancies have been carried out. In the context of these clinical trials, measuring of serum levels of PETN and its metabolites pentaerythrityl trinitrate (PETriN), pentaerythrityl dinitrate (PEDN), pentaerythrityl mononitrate (PEMN) and pentaerythritol (PE) were required. To evaluate the transfer of PETN and its metabolites (PEXN) from the mother to the fetus using samples from a human clinical trial and animal study, the present work aimed to develop a rapid and simple method to simultaneously analyze PEXN in human and ovine samples. A method employing a rapid and simple liquid-liquid extraction followed by reversed-phase (C18) liquid chromatography coupled to high-resolution mass spectrometry with negative electrospray ionization was developed and validated for the detection of PETN and PEXN in human and ovine samples. PE could only be qualitatively detected at higher concenrations. Method validation requirements, including accuracy, repeatability and intermediate precision were fulfilled in ovine and human samples for all other PEXN with exception PETriN in human samples. The recovery (RE) in ovine samples was 76.7 % ± 12 % for PEMN, 98 % ± 23 % for PEDN, 94 % ± 22 % for PETriN, in human samples RE was 59 % ± 16 % for PEMN, 67 % ± 19 % for PEDN, 71 % ± 17 %. The matrix effects (ME) in ovine samples were 90 % ± 11 % for PEMN, 70 % ± 30 % for PEDN, 107 % ± 17 % for PETriN, in human samples the ME were 93 % ± 13 % for PEMN, 84 % ± 17 % for PEDN, 98 % ± 16 % for PETriN. The limits of quantification (LOQ) in ovine samples were 1.0 ng/mL for PETriN and 0.1 ng/mL for PEMN and PEDN. The LOQs in human samples were 5.0 ng/mL for PETriN and 0.3 ng/mL for PEMN und PEDN. The newly developed method was used to analyze 184 ovine serum samples and 18 human plasma samples. In ovine maternal samples, the highest observed PEDN concentration was 3.5 ng/mL and the highest PEMN concentration was 10 ng/mL, the respective concentrations in fetal serum samples were 4.9 ng/mL for PEDN and 5.4 ng/mL for PEMN. PETriN was only detected in traces in maternal and fetal samples, whereas PETN could not be detected at all. In human maternal samples, the highest concentration for PEDN was 27 ng/mL and for PEMN 150 ng/mL. In umbilical cord plasma, concentrations of 2.3 ng/mL for PEDN and 73 ng/mL for PEMN were detected. Although the PEMN and PEDN concentrations in the human samples were several times higher than in ovine samples, neither PETN nor PETriN signals could be detected. These results demonstrated that the metabolites were transferred from mother to fetus with a slight time delay.


Asunto(s)
Tetranitrato de Pentaeritritol , Animales , Femenino , Humanos , Embarazo , Espectrometría de Masas , Tetranitrato de Pentaeritritol/sangre , Placenta , Ovinos
5.
J Anal Toxicol ; 48(1): 37-43, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-37933588

RESUMEN

Ensuring specimen validity is an essential aspect of toxicological laboratories. In recent years, substituting authentic urine specimens for synthetic urine (SU) has become increasingly popular. Such SU products consist of components expected in normal urine and show physiological values for specific gravity and pH. Thus, standard specimen validity testing may fail in revealing adulteration by SU. The present study investigated three methods to distinguish authentic and SU specimens: enzymatic detection of uric acid, the commercially available Axiom Test True SU and liquid chromatography coupled with (tandem) mass spectrometry (LC-MS-MS) analysis of 10 endogenous biomolecules. Additionally, novel direct markers of SU were investigated. Two specimen sets were analyzed by each method. Specimen set A consisted of eight SU products purchased from the Austrian/German market and 43 urine specimens from volunteers of known authenticity, which underwent double-blind analysis. Specimen set B consisted of 137 real urine specimens submitted for drug testing, which were selected due to initial suspicious test results in adulteration testing and reanalyzed by all three methods. Uric acid and LC-MS-MS-based endogenous biomolecule testing showed 100% sensitivity and specificity for set A. The commercial test had 87.5% sensitivity and 97.7% specificity for set A. For set B, uric acid and LC-MS-MS analysis showed almost similar results, even if uric acid was missing one presumptive authentic urine specimen according to LC-MS-MS findings. Nearly half of the SU assignments for the commercial test were presumptive false positives. New SU markers were observed for SU products from the Austrian/German market. One specimen in set B had both an endogenous biomolecule pattern and SU markers suggesting urine dilution with SU. In conclusion, several analytes or methods should be used rather than one, and the most reliable results are achieved if both indirect and direct markers of urine substitution are analyzed.


Asunto(s)
Cromatografía Líquida con Espectrometría de Masas , Espectrometría de Masas en Tándem , Humanos , Cromatografía Liquida/métodos , Espectrometría de Masas en Tándem/métodos , Ácido Úrico , Detección de Abuso de Sustancias/métodos
6.
Opt Express ; 31(18): 29619-29626, 2023 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-37710758

RESUMEN

A tunable comb source is demonstrated on a monolithically integrated photonic integrated circuit (PIC). The PIC is a two section device designed to produce a single mode tunable spectrum, and the comb is generated by gain switching one section of the two sectioned laser. The laser produces a single mode spectra with a tunable range of 1543 - 1565 nm, and combs were generated with a frequency range of 1 - 10 GHz without requiring additional optical injection to maintain the phase coherence.

7.
Opt Lett ; 48(15): 4137-4140, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37527137

RESUMEN

A tunable comb source is demonstrated through gain switching on a three-sectioned photonic integrated circuit (PIC). The PIC consists of two mutually coupled lasers connected by a passive waveguide. One of these is a tunable, two-section, single mode laser. The second laser is a simple Fabry-Perot cavity laser which can be phase-locked with the single mode laser via bidirectional coupling. Frequency combs are produced by gain switching the Fabry-Perot laser by applying a high-power radio frequency signal. Combs are generated with line spacings ranging from 3.5 to 8 GHz. The on-chip bidirectional coupling causes the comb to also be generated in the two-section device. Despite the lack of on-chip optical isolation between the lasers, the resulting combs are stable. Numerical simulations using a delay-differential model reproduce the results and reveal the important role played by the short delay times inherent to on-chip integration in this stability.

8.
Expert Opin Drug Metab Toxicol ; 19(8): 487-500, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37615282

RESUMEN

INTRODUCTION: Hyphenated mass spectrometry (MS) has evolved into a very powerful analytical technique of high sensitivity and specificity. It is used to analyze a very wide spectrum of analytes in classical and alternative matrices. The presented paper will provide an overview of the current state-of-the-art of hyphenated MS applications in clinical toxicology primarily based on review articles indexed in PubMed (1990 to April 2023). AREAS COVERED: A general overview of matrices, sample preparation, analytical systems, detection modes, and validation and quality control is given. Moreover, selected applications are discussed. EXPERT OPINION: A more widespread use of hyphenated MS techniques, especially in systematic toxicological analysis and drugs of abuse testing, would help overcome limitations of immunoassay-based screening strategies. This is currently hampered by high instrument cost, qualification requirements for personnel, and less favorable turnaround times, which could be overcome by more user-friendly, ideally fully automated MS instruments. This would help making hyphenated MS-based analysis available in more laboratories and expanding analysis to a large number of organic drugs, poisons, and/or metabolites. Even the most recent novel psychoactive substances (NPS) could be presumptively identified by high-resolution MS methods, their likely presence be communicated to treating physicians, and be confirmed later on.


Asunto(s)
Toxicología , Humanos , Cromatografía de Gases y Espectrometría de Masas/métodos , Espectrometría de Masas/métodos , Toxicología/métodos
9.
J Biomech ; 147: 111435, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36641827

RESUMEN

Internal organs such as the heart demonstrate apparent left-right (LR) asymmetric morphology and positioning. Cellular chirality and associated LR biased mechanical behavior such as cell migration have been attributed to LR symmetry breaking during embryonic development. Mathematical models have shown that chiral directional migration can be driven by cellular intrinsic torque. Tissue jamming state (i.e., solid-like vs fluid-like state) strongly regulates collective migratory behavior, but how it might affect chiral morphogenesis is still unknown. Here, we develop a cell vertex model to study the role of tissue rigidity or jamming state on chiral morphogenesis of the cells on a patterned ring-shaped tissue, simulating a previously reported experimental setup for measuring cell chirality. We simulate chirality as torsional forces acting on cell vertices. As expected, the cells undergo bidirectional migration at the opposing (inner and outer) boundaries of the ring-shaped tissue. We discover that more fluid-like tissues (unjammed) demonstrate a stronger chiral cell alignment and elongation than more solid-like (jammed) tissues and maintain a bigger difference in migration velocity between opposing tissue boundaries. Finally, we find that fluid-like tissues undergo more cell-neighbor exchange events. This study reveals that chiral torque is sufficient to achieve a biased cellular alignment as seen in vitro. It further sheds light on the mechanical regulation of chiral morphogenesis of tissues and reveals a role of cell density-independent tissue rigidity in this process.


Asunto(s)
Tipificación del Cuerpo , Corazón , Tipificación del Cuerpo/fisiología , Morfogénesis , Movimiento Celular/fisiología
10.
Forensic Sci Int ; 339: 111420, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35985138

RESUMEN

Analysis of endogenous biomolecules is an important aspect of many forensic investigations especially with focus on DNA analysis for perpetrator/victim identification and protein analysis for body fluid identification. Recently, small endogenous biomolecules have been used for differentiation of synthetic "fake" urine from authentic urine and might be also useful for biofluid identification. Therefore, the aim of this study was to adapt and optimize a method for analysis of small EBs and to investigate long time stability of 35 small endogenous biomolecules (including acylcarnitines with their isomers and metabolites as well as amino acids with their metabolites) in spotted urine samples. Urine samples were spotted on seven different surfaces (Whatman 903 Protein Saver Cards, cotton swabs, cotton glove, denim, underwear, and smooth and rough flagstone) and stored under six environmental conditions (reference condition, sunlight, LED light, 4 °C, 37 °C, humidity of 95%). At certain time points (d0, d7, d28 and d56) samples were analyzed in triplicates by an optimized extraction and LC-HRMS approach. In addition, the urine marker Tamm-Horsfall-Protein was determined on cotton swabs at the same time points using a commercial lateral flow test. Twenty-one of 35 small endogenous biomolecules were stable on most materials/surfaces and under most storage conditions. Significant lower endogenous biomolecule peak areas were found for rough flagstone and underwear as well as for high humidity storage. Kynurenic acid proved to be photo labile. While high long time stabilities were found for 19 of 28 acylcarnitines, nine acylcarnitines showed aberrant stability patterns without evident structural reason. For Tamm-Horsfall-Protein degradation within 28 days was observed even under reference conditions. The presented study demonstrated the value of sensitive LC-HRMS analysis for small endogenous biomolecules / pattern. However, further studies will be indispensable for unambiguous body fluid identification by small endogenous biomolecules.


Asunto(s)
Líquidos Corporales , Manejo de Especímenes , Aminoácidos , Líquidos Corporales/química , Carnitina/análogos & derivados , Carnitina/análisis , Manejo de Especímenes/métodos
11.
Curr Pharm Des ; 28(15): 1230-1244, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35619258

RESUMEN

The use of high-resolution mass spectrometry (HRMS) has increased over the past decade in clinical and forensic toxicology, especially for comprehensive screening approaches. Despite this, few guidelines in this field have specifically addressed HRMS issues concerning compound identification, validation, measurement uncertainty and quality assurance. To fully implement this technique, certainly in an era in which the quality demands for laboratories are ever-increasing due to various norms (e.g. the International Organization for Standardization's ISO 17025), these specific issues need to be addressed. This manuscript reviews 26 HRMSbased methods for qualitative systematic toxicological analysis (STA) published between 2011 and 2021. Key analytical data such as samples matrices, analytical platforms, numbers of analytes and employed mass spectral reference databases/libraries as well as the studied validation parameters are summarized and discussed. The article further includes a critical review of targeted and untargeted data acquisition approaches, available HRMS reference databases and libraries as well as current guidelines for HRMS data interpretation with a particular focus on identification criteria. Moreover, it provides an overview on current recommendations for the validation and determination of measurement uncertainty of qualitative methods. Finally, the article aims to put forward suggestions for method development, compound identification, validation experiments to be performed, and adequate determination of measurement uncertainty for this type of wide-range qualitative HRMSbased methods.


Asunto(s)
Toxicología Forense , Cromatografía Liquida/métodos , Toxicología Forense/métodos , Humanos , Espectrometría de Masas/métodos
12.
Br J Clin Pharmacol ; 87(11): 4293-4303, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-33818823

RESUMEN

AIMS: To describe the population pharmacokinetics (PK) and probability of target attainment (PTA) of continuous infusion (CI) of meropenem in septic patients receiving renal replacement therapy (RRT). METHODS: Fifteen patients without RRT, 13 patients receiving sustained low-efficiency dialysis and 12 patients receiving continuous veno-venous haemodialysis were included. Population PK analysis with Monte Carlo simulations for different dosing regimens was performed. For minimum inhibitory concentration 2 mg/L was chosen. The target was set as 50% time ≥4× minimum inhibitory concentration. RESULTS: The PK of meropenem was best described by a 1-compartment model with linear elimination. Serum creatinine, residual diuresis and time on RRT, with no difference between sustained low-efficiency dialysis and continuous veno-venous haemodialysis, were found to be significant covariates affecting clearance, explaining >20% of the clearance between subject variability. PTA analysis showed that in patients with RRT, 2 g/24 h, meropenem CI achieved a PTA of 95%. In patients without RRT, the target was achieved with 3 g/24 h CI or prolonged infusion of 1 g meropenem over 8 hours but not with bolus application of 1 g meropenem for 8 hours. Only 2 patients (both without RRT) had meropenem concentrations below the target level. However, approximately half of the patients with RRT receiving CI 3 g/24 h meropenem had toxic concentrations. CONCLUSION: We found relevant PK variability for meropenem CI in septic patients with or without RRT, leading to a substantial risk for overdosing in patients with RRT. This finding highlights the strong demand for personalized dosing in critically ill patients.


Asunto(s)
Terapia de Reemplazo Renal Continuo , Terapia de Reemplazo Renal Híbrido , Sepsis , Antibacterianos/uso terapéutico , Humanos , Meropenem , Probabilidad , Terapia de Reemplazo Renal , Sepsis/tratamiento farmacológico
13.
J Pharm Biomed Anal ; 197: 113954, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33601161

RESUMEN

Dolutegravir is an integrase strand transfer inhibitor used for the treatment of human immuno-deficiency virus infections. The present study was conducted in order to identify degradation products formed in acidic solution upon heating. The structures were assigned based on low resolution collision-induced dissociation tandem mass spectra as well as high resolution higher-energy collisional dissociation tandem mass spectra. The major degradation products resulted from hydrolytic opening of the oxepine ring leading to bis-hydroxy diastereomers (DP2 and DP3) as well as a mono-hydroxy derivative (DP1) as the result of dehydration of the diastereomers. Furthermore, two carboxylic acid derivatives (DP4 and DP5) could be identified, which can be explained as the result of the hydrolysis of the exocyclic amide bond of dolutegravir and DP1, respectively. During the fragmentation process of dolutegravir and its degradation products DP1 to DP3 a formal addition of oxygen resulting in the respective carboxylic acid fragments was detected. This could be evidenced based on high resolution masses of the fragments as well as the comparison of the MS/MS spectra of the fragments with the spectra of the carboxylic acids DP4 and DP5.


Asunto(s)
Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masas en Tándem , Cromatografía Líquida de Alta Presión , Compuestos Heterocíclicos con 3 Anillos , Humanos , Oxazinas , Piperazinas , Piridonas
14.
Clin Genitourin Cancer ; 19(3): 274.e1-274.e16, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33317946

RESUMEN

BACKGROUND: Nivolumab, a programmed death 1 inhibitor, has been approved as second-line treatment for advanced renal cell carcinoma (RCC) in Europe since 2016. We investigated the toxicity and efficacy of nivolumab as well as potential predictive biomarkers in the Dutch population. PATIENTS AND METHODS: This was a retrospective, multicenter study of the Dutch national registry of nivolumab for the treatment of advanced RCC. The main outcome parameters included toxicity, objective response rate (ORR), overall survival (OS), progression-free survival (PFS), time to progression (TTP), and time to treatment failure (TTF). In addition, potential predictive and prognostic biomarkers for outcomes were evaluated. RESULTS: Data on 264 patients were available, of whom 42% were International Metastatic RCC Database Consortium (IMDC) poor risk at start of nivolumab, 16% had ≥ 3 lines of previous therapy, 7% had non-clear-cell RCC, 11% had brain metastases, and 20% were previously treated with everolimus. Grade 3/4 immune-related adverse events occurred in 15% of patients. The median OS was 18.7 months (95% confidence interval, 13.7-23.7 months). Progression occurred in 170 (64.4%) of 264 patients, with a 6-and 12-months TTP of 49.8% and 31.1%, respectively. The ORR was 18.6% (49 of 264; 95% confidence interval, 14%-23%). Elevated baseline lymphocytes were associated with improved PFS (P = .038) and elevated baseline lactate dehydrogenase with poor OS, PFS, and TTF (P = .000). On-treatment increase in eosinophils by week 8 predicted improved OS (P = .003), PFS (P = .000), and TTF (P = .014), whereas a decrease of neutrophils was associated with significantly better TTF (P = .023). CONCLUSIONS: The toxicity and efficacy of nivolumab for metastatic RCC after previous lines of therapy are comparable with the results in the pivotal phase III trial and other real-world data. On-treatment increase in eosinophil count is a potential biomarker for efficacy and warrants further investigation.


Asunto(s)
Carcinoma de Células Renales , Neoplasias Renales , Biomarcadores , Carcinoma de Células Renales/tratamiento farmacológico , Humanos , Neoplasias Renales/tratamiento farmacológico , Países Bajos , Nivolumab/efectos adversos , Estudios Retrospectivos
16.
Phys Rev E ; 102(3-1): 030201, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33075975

RESUMEN

The discrete circle map is the archetypical example of a driven periodic system, showing a complex resonance structure under a change of the forcing frequency known as the devil's staircase. Adler's equation can be seen as the direct continuous equivalent of the circle map, describing locking effects in periodic systems with continuous forcing. This type of locking produces a single fundamental resonance tongue without higher-order resonances, and a devil's staircase is not observed. We show that, with harmonically modulated forcing, nonlinear oscillations close to a Hopf bifurcation generically reproduce the devil's staircase even in the continuous case. Experimental results on a semiconductor laser driven by a modulated optical signal show excellent agreement with our theoretical predictions. The locking appears as a modulation of the oscillation amplitude as well as the angular oscillation frequency. Our results show that by proper implementation of an external drive, additional regions of stable frequency locking can be introduced in systems which originally show only a single Adler-type resonance tongue. The induced resonances can be precisely controlled via the modulation parameters.

17.
Opt Express ; 28(21): 31904-31913, 2020 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-33115154

RESUMEN

This paper presents our research on quantum well intermixing (QWI) of InP-based AlGaInAs/AlGaInAs multi-quantum wells using impurity-free vacancy-disordering (IFVD) and the QWI mask proximity effect and its application in the design and fabrication of a teardrop laser. Using a Si3N4 film deposited by plasma-enhanced chemical vapor deposition (PECVD) as a QWI promoter mask and annealing under 700°C for 2 minutes, a 70 nm wavelength blue shift of a FP laser is achieved using InP-based AlGaInAs quantum well laser material. It is found that a 5 µm separation is needed between the QWI mask edges and the non-QWI area during the QWI process. Based on the QWI technique and proximity effect, the designed and fabricated teardrop laser demonstrated continuous wave (CW) lasing above 40 mA and single frequency operation with a side mode suppression ratio of 32.6 dB at 77.3 mA.

18.
Opt Express ; 28(11): 16900-16906, 2020 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-32549503

RESUMEN

A monolithically integrated dual-channel optical frequency comb source is demonstrated in this paper. Three lasers are integrated on a single chip using a regrowth-free fabrication process in a master-slave-slave configuration. The master laser's power is split equally using a 1x2 multimode interference coupler and injection locks the two slave lasers. The slave lasers are gain-switched to produce dual optical frequency combs at 4.1 GHz and 5 GHz. To the best of our knowledge, this is the first demonstration of a dual optical frequency comb source with all light sources monolithically integrated in a photonic integrated circuit (PIC).

19.
Opt Lett ; 45(8): 2223-2226, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-32287199

RESUMEN

We investigate the dynamics of asymmetrically coupled semiconductor lasers on photonic integrated circuits in experiment and theory. The experimental observations are explained using a rate-equation model for coupled lasers incorporating a saturable coupling waveguide. We perform a bifurcation analysis of the coupled laser dynamics, focusing on the effects of the coupling phase and the dynamical difference between passive and saturable coupling waveguides. For a passive waveguide, we find a bifurcation scenario closely resembling the well-known optical injection setup, which is largely insensitive to the coupling phase. When the coupling waveguide is saturable, the dynamics become increasingly complex and unpredictable, with a strong phase-dependence. Our results show the possibility of a simple layout for reproducible laser dynamics on a chip.

20.
Clin Genitourin Cancer ; 18(3): e233-e253, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-31883940

RESUMEN

BACKGROUND: The purpose of this study was to determine generic, cancer-specific, and prostate cancer-specific health-related quality of life (HRQoL), pain and changes over time in patients with metastatic castration-resistant prostate cancer (mCRPC) in daily practice. PATIENTS AND METHODS: PRO-CAPRI is an observational, prospective study in 10 hospitals in the Netherlands. Patients with mCRPC completed the EQ-5D, European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30), and Brief Pain Inventory-Short Form (BPI-SF) every 3 months and European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire-Prostate Cancer Module (EORTC QLQ-PR25) every 6 months for a maximum of 2 years. Subgroups were identified based on chemotherapy pretreatment. Outcomes were generic, cancer-specific, and prostate cancer-specific HRQoL and self-reported pain. Descriptive statistics were performed including changes over time and minimal important differences (MID) between subgroups. RESULTS: In total, 151 included patients answered 873 questionnaires. The median follow-up from the start of the study was 19.5 months, and 84% were treated with at least 1 life-prolonging agent. Overall, patients were in good clinical condition (Eatern Cooperative Oncology Group performance status 0-1 in 78%) with normal baseline hemoglobin, lactate dehydrogenase, and alkaline phosphatase. At inclusion, generic HRQoL was high with a mean EQ visual analog score of 73.2 out of 100. The lowest scores were reported on role and physical functioning (mean scores of 69 and 76 of 100, respectively), and fatigue, pain, and insomnia were the most impaired domains. These domains deteriorated in > 50% of patients. CONCLUSION: Although most patients were treated with new treatments during follow-up, mCRPC has a negative impact on HRQoL with deterioration in all domains over time, especially role and physical functioning. These domains need specific attention during follow-up to maintain HRQoL as long as possible by timely start of adequate supportive care management.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Dolor en Cáncer/epidemiología , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico , Calidad de Vida , Anciano , Anciano de 80 o más Años , Dolor en Cáncer/inducido químicamente , Dolor en Cáncer/patología , Dolor en Cáncer/psicología , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Pronóstico , Estudios Prospectivos , Neoplasias de la Próstata Resistentes a la Castración/psicología , Encuestas y Cuestionarios , Tasa de Supervivencia
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