Chemometric analysis of mass spectral data for the purpose of differentiating positional isomers of novel psychoactive substances has seen a substantial increase in popularity in recent years. However, the process of generating a large and robust dataset for chemometric isomer identification is time consuming and impractical for forensic laboratories. To begin to address this problem, three sets of ortho/meta/para positional ring isomers (fluoroamphetamine (FA), fluoromethamphetamine (FMA), and methylmethcathinone (MMC)) were analyzed using multiple GC-MS instruments at three distinct laboratories.
View Article and Find Full Text PDFWe put forth a theoretical model allowing for the analysis of short-pulse interactions at time boundaries in waveguides with arbitrary frequency-dependent nonlinear profiles, in particular those exhibiting a zero-nonlinearity wavelength. Moreover, this is performed within a photon-conserving framework, thus circumventing use of the nonlinear Schrödinger equation in such scenarios, as it may lead to unphysical outcomes. Results indicate that the waveguide zero-nonlinearity wavelength has a great influence on said interactions, specifically by defining spectral bands where either signal total reflection or signal transmission can occur.
View Article and Find Full Text PDFWe analyzed 324,734 SARS-CoV-2 variant screening tests from France enriched with 16,973 whole-genome sequences sampled during September 1, 2021-February 28, 2022. Results showed the estimated growth advantage of the Omicron variant over the Delta variant to be 105% (95% CI 96%-114%) and that of the BA.2 lineage over the BA.
View Article and Find Full Text PDFThe differentiation of positional isomers is a well established analytical challenge for forensic laboratories. As more novel psychoactive substances (NPSs) are introduced to the illicit drug market, robust yet efficient methods of isomer identification are needed. Although current literature suggests that Direct Analysis in Real Time-Time-of-Flight mass spectrometry (DART-ToF) with in-source collision induced dissociation (is-CID) can be used to differentiate positional isomers, it is currently unclear whether this capability extends to positional isomers whose only structural difference is the precise location of a single substitution on an aromatic ring.
View Article and Find Full Text PDFThe production of industrial waste has increased in the last decades along with world population. Wastes are used in agriculture as fertilizers and soil amendments depending on their composition, dynamics in soil and effects on plant growth. The aim of this study was to assess the effect of industrial saline wastewater from heparin production on soil chemistry and plant yield in a subtropical soil in Brazil.
View Article and Find Full Text PDFThe present dataset was collected to evaluate the environmental stressors on a lacustrine basin in the Eastern Alps of glacial origin that has been affected in recent years by natural and anthropogenic events such as the construction of a hydroelectric power plant and a series of strong earthquakes during 1976-1977. We collected sediment cores in different sites from the lake margins to the depocenter and performed a multiproxy analysis of sediment sample to highlight lake stratigraphy and major changes occurring at a decadal scale (Polonia et al., [1]).
View Article and Find Full Text PDFIn this Letter we introduce a novel equation addressing the effect of quantum noise in optical fibers with arbitrary frequency-dependent nonlinear profiles. To the best of our knowledge, such an endeavor has not been undertaken before despite the growing relevance of fiber optics in the design of new quantum devices. We show that the stochastic generalized nonlinear Schrödinger equation, derived from a quantum theory of optical fibers, leads to unphysical results such as a negative photon number and the appearance of a dominant anti-Stokes sideband when applied to this kind of waveguides.
View Article and Find Full Text PDFMonocytes/macrophages and vascular smooth muscle cells (vSMCs) are the main cell types implicated in atherosclerosis development, and unlike other mature cell types, both retain a remarkable plasticity. In mature vessels, differentiated vSMCs control the vascular tone and the blood pressure. In response to vascular injury and modifications of the local environment (inflammation, oxidative stress), vSMCs switch from a contractile to a secretory phenotype and also display macrophagic markers expression and a macrophagic behaviour.
View Article and Find Full Text PDFIn this Letter, we revisit the quantum theory of propagation in nonlinear fibers. Unlike previous works, we present an effective propagation equation for the reduced density matrix of the complex envelope of the electric field. This original proposal is shown to be in agreement with the theory of quantum noise in fibers and puts forth a powerful tool for the study of fiber-based quantum devices.
View Article and Find Full Text PDFEnviron Monit Assess
September 2020
Here, we present a framework for a beach litter monitoring process, based on free and open-source software (FOSS), which allows customization for any sampling design. The framework was developed by means of a GIS project (QGIS), a GIS collector (QField), and an R code, allowing further adjustments according to the area to be surveyed and research questions. The aim is to improve data collection, accessibility, and interoperability, as well as to help to fill the currently existing gap between fieldwork and data analysis, preventing typos and allowing better data processing.
View Article and Find Full Text PDFWe propose an original, simple, and direct method to measure self-steepening (SS) in nonlinear waveguides. Our proposal is based on results derived from the recently introduced photon-conserving nonlinear Schrödinger equation (NLSE) and relies on the time shift experienced by soliton-like pulses due to SS upon propagation. In particular, a direct measurement of this time shift allows for a precise estimation of the SS parameter.
View Article and Find Full Text PDFObjective: This study evaluates melanoma characteristics in the elderly.
Methods: A retrospective descriptive analytical study was carried out by reviewing the medical records of patients aged 60 years or older, diagnosed with primary cutaneous melanoma, and treated at Hospital Erasto Gaertner, Curitiba, Paraná, from 2013 to 2017.
Results: We studied 139 patients aged 60-98 years (average, 70.
This study proposes a novel methodology to define protected area (PA) categories based on the analysis of how much a PA can protect important ecosystem services (ESs). PA are important tools to minimize the continuing global biodiversity conservation crisis. However, the contribution of PA to conservation is variable, mainly due to the diverse management categories with which they can be associated.
View Article and Find Full Text PDFWe exploit the anisotropic plasmonic behavior of gold nanorods (AuNRs) to obtain a waveguide with a nonlinear coefficient dependent on both the frequency and polarization of incident light. The optical properties of the waveguide are described by an extension of the Maxwell Garnett model to nonlinear optics and anisotropic nanoparticles. Then, we perform a study of modulation instability (MI) in this system by resorting to the recently introduced photon-conserving nonlinear Schrödinger equation (pcNLSE), as the pcNLSE allows us to model propagation in nonlinear waveguides of arbitrary sign and frequency dependence of the nonlinear coefficient.
View Article and Find Full Text PDFIn this Letter, we present, for the first time, to the best of our knowledge, the modulation instability (MI) gain spectrum of waveguides with an arbitrary frequency-dependent nonlinear coefficient ensuring strict energy and photon-number conservation of the parametric process. This is achieved by starting from a linear stability analysis of the recently introduced photon-conserving nonlinear Schrödinger equation. The derived MI gain is shown to predict some unique features, such as a nonzero gain extending beyond a zero-nonlinearity wavelength and a complex structure of the MI gain spectrum.
View Article and Find Full Text PDFIdentifying drug analogs can be a vexing problem for forensic scientists particularly in today's evolving drug market. This study proposes a method that utilizes microcrystalline tests, Raman microspectroscopy, and chemometrics to help solve this problem. In the present case, the method described was used to clearly differentiate and identify phencyclidine (PCP) and four of its analogs, namely tenocyclidine (TCP), rolicyclidine (PCPy), 3-methoxy phencyclidine (3-MeO PCP), and 4-methoxy phencyclidine (4-MeO PCP).
View Article and Find Full Text PDFSoil mechanical resistance, aeration, and water availability directly affect plant root growth. The objective of this work was to identify the contribution of mechanical and hydric stresses on maize root elongation, by modeling root growth while taking the dynamics of these stresses in an Oxisol into consideration. The maize crop was cultivated under four compaction levels (soil chiseling, no-tillage system, areas trafficked by a tractor, and trafficked by a harvester), and we present a new model, which allows to distinguish between mechanical and hydric stresses.
View Article and Find Full Text PDFAsbestos is the main causative agent of malignant pleural mesothelioma. The variety known as crocidolite (blue asbestos) owns the highest pathogenic potential, due to the dimensions of its fibers as well as to its content of iron. The latter can in fact react with macrophage-derived hydrogen peroxide in the so called Fenton reaction, giving rise to highly reactive and mutagenic hydroxyl radical.
View Article and Find Full Text PDFWe propose a novel and simple method for estimating the fractional Raman contribution, f, based on an analysis of a full model of modulation instability (MI) in waveguides. An analytical expression relating f to the MI peak gain beyond the cutoff power is explicitly derived, allowing for an accurate estimation of f from a single measurement of the Raman gain spectrum.
View Article and Find Full Text PDF-Nitrosothiols are ˙NO releasing agents renowned for vasodilatory and antioxidant properties. O˙ promotes their decomposition, forming highly aggressive peroxynitrite ions (ONOO). Since the production of O˙ can be controlled by enzymes or by visible light, such otherwise harmless components can be turned into effective antimicrobial and nematicidal combinations with numerous potential applications in medicine.
View Article and Find Full Text PDFThe damage of coastal infrastructure due to wave action has stimulated the need for vulnerability assessments for integrated coastal management. Vulnerability is described as the ability of people living in an area to anticipate, cope with, resist and recover from the impact produced by a coastal hazard. This study aims to develop a multi-criteria index to assess coastal vulnerability to waves.
View Article and Find Full Text PDFRationale: The potency of S-nitrosoglutathione (GSNO) as a nitric oxide (NO) donor to treat cardiovascular diseases (CVDs) has been highlighted in numerous studies. In order to study its bioavailability after oral administration, which represents the most convenient route for the chronic treatment of CVDs, it is essential to develop an analytical method permitting (i) the simultaneous measurement of GSNO metabolites, i.e.
View Article and Find Full Text PDFBiochem Pharmacol
September 2018
S-Nitrosothiols, a class of NO donors, demonstrate potential benefits for cardiovascular diseases. Drugs for such chronic diseases require long term administration preferentially through the oral route. However, the absorption of S-nitrosothiols by the intestine, which is the first limiting barrier for their vascular bioavailability, is rarely evaluated.
View Article and Find Full Text PDFEight touristic beaches along the north coast of Santa Catarina Island, Brazil were assessed to determine litter influence on scenic quality. The application of the Coastal Scenic Evaluation System (CSES) categorized these beaches into four of the five available classes. Six of the investigated beaches belong to Class III (n = 3) and V (n = 3), while two beaches correspond to Class II and Class IV.
View Article and Find Full Text PDFWhich scientist has never heard of glutathione (GSH)? This well-known low-molecular-weight tripeptide is perhaps the most famous natural antioxidant. However, the interest in GSH should not be restricted to its redox properties. This multidisciplinary review aims to bring out some lesser-known aspects of GSH, for example, as an emerging tool in nanotechnologies to achieve targeted drug delivery.
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