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Label-free optical imaging of single-nanometer-scale matter is extremely important for a variety of biomedical, physical, and chemical investigations. One central challenge is that the background intensity is much stronger than the intensity of the scattering light from single nano-objects. Here, we propose an optical module comprising cascaded momentum-space polarization filters that can perform vector field modulation to block most of the background field and result in an almost black background; in contrast, only a small proportion of the scattering field is blocked, leading to obvious imaging contrast enhancement. This module can be installed in various optical microscopies to realize a black-field microscopy. Various single nano-objects with dimensions smaller than 20 nm appear distinctly in the black-field images. The chemical reactions occurring on single nanocrystals with edge lengths of approximately 10 nm are in situ real-time monitored by using the black-field microscopy. This label-free black-field microscopy is highly promising for a wide range of future multidisciplinary science applications.
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Rationale: Air pollution caused by wildfire smoke is linked to adverse health outcomes, especially for people living with asthma. Objectives: To evaluate whether government rebates for high-efficiency particulate air (HEPA) filters, which reduce concentrations of smoke particles indoors, are cost effective in managing asthma and preventing exacerbations in British Columbia (BC), Canada. Methods: We used a Markov model to analyze health states for asthma control, exacerbation severity, and death over a retrospective time horizon of 5 years (2018-2022). Concentrations of wildfire smoke-derived particulate matter with an aerodynamic diameter ⩽2.5 µm (PM2.5) from the Canadian Optimized Statistical Smoke Exposure Model and relevant literature informed the model. The base-case analysis assumed continuous use of a HEPA filter. Costs and quality-adjusted life-years (QALYs) resulting from varying rebates were computed for each Health Service Delivery Area (HSDA). Measurements and Main Results: In the base-case analysis, HEPA filter use resulted in increased costs of $83.34 (SE, $1.03) and increased QALYs of 0.0011 (SE, 0.0001) per person. The average incremental cost-effectiveness ratio among BC HSDAs was $74,652/QALY (SE, $3,517), with incremental cost-effectiveness ratios ranging from $40,509 to $89,206 per QALY in HSDAs. Across the province, the intervention was projected to prevent 4,418 exacerbations requiring systemic corticosteroids, 643 emergency department visits, and 425 hospitalizations during the 5-year time horizon. A full rebate was cost effective in 1 of the 16 HSDAs across BC. The probability of cost-effectiveness ranged from 0.1% to 74.8% across HSDAs. A $100 rebate was cost effective in most HSDAs. Conclusions: The cost-effectiveness of HEPA filters in managing wildfire smoke-related asthma issues in BC varies by region. Government rebates up to two-thirds of the filter cost are generally cost effective, with a full rebate being cost effective only in Kootenay Boundary.
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Filtros de Ar , Poluentes Atmosféricos , Poluição do Ar , Asma , Incêndios Florestais , Humanos , Análise Custo-Benefício , Filtros de Ar/efeitos adversos , Estudos Retrospectivos , Asma/etiologia , Material Particulado/efeitos adversos , Material Particulado/análise , Poluição do Ar/efeitos adversos , Poluição do Ar/prevenção & controle , Poluição do Ar/análise , Poeira , Colúmbia Britânica , Poluentes Atmosféricos/efeitos adversosRESUMO
The deep sea contains a surprising diversity of life, including iconic fish groups such as anglerfishes and lanternfishes. Still, >65% of marine teleost fish species are restricted to the photic zone <200 m, which comprises less than 10% of the ocean's total volume. From a macroevolutionary perspective, this paradox may be explained by three hypotheses: 1) shallow water lineages have had more time to diversify than deep-sea lineages, 2) shallow water lineages have faster rates of speciation than deep-sea lineages, or 3) shallow-to-deep sea transition rates limit deep-sea richness. Here we use phylogenetic comparative methods to test among these three non-mutually exclusive hypotheses. While we found support for all hypotheses, the disparity in species richness is better described as the uneven outcome of alternating phases that favored shallow or deep diversification over the past 200 million y. Shallow marine teleosts became incredibly diverse 100 million y ago during a period of warm temperatures and high sea level, suggesting the importance of reefs and epicontinental settings. Conversely, deep-sea colonization and speciation was favored during brief episodes when cooling temperatures increased the efficiency of the ocean's carbon pump. Finally, time-variable ecological filters limited shallow-to-deep colonization for much of teleost history, which helped maintain higher shallow richness. A pelagic lifestyle and large jaws were associated with early deep-sea colonists, while a demersal lifestyle and a tapered body plan were typical of later colonists. Therefore, we also suggest that some hallmark characteristics of deep-sea fishes evolved prior to colonizing the deep sea.
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Peixes , Água , Animais , Carbono , Ecossistema , FilogeniaRESUMO
Particulate matter pollution has become a serious public health issue, especially with the outbreak of new infectious diseases. However, most existing air filtration materials face challenges such as being too bulky, having high resistance, and a trade-off between filtration efficiency and air permeability. Here, a unique electro-blown spinning technique is used to prepare an air filter made of biomimetic nanoscaled tendril nonwovens (Nano-TN). The introduction of an airflow field significantly increases the whipping frequency and the strain mismatch of composite jets, achieving large-scale and highly efficient preparation of Nano-TN. The resultant Nano-TN has an ultrahigh porosity (97%) and a small pore size (2.9 µm). At the same filtration level, its air resistance is 37% lower than that of traditional straight nanofibrous nonwovens and has a higher dust-holding capacity. Moreover, compared with traditional three-dimensional air filters, the Nano-TN filter is thinner, offering tremendous application prospects in various environmental purification and personal protection fields.
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Filtros de Ar , Biomimética , Filtração/métodos , Material ParticuladoRESUMO
Tunable thin-film coating-based reflective color displays have versatile applications including image sensors, camouflage devices, spatial light modulators, and intelligent windows. However, generating high-purity colors using such coatings have posed a challenge. Here, we reveal high-purity color generation using an ultralow-loss phase change material (Sb2S3)-based tunable aperiodic distributed Bragg reflector (A-DBR). By strategically adjusting the periodicity of the adjacent layers of A-DBRs, we realize a narrow photonic bandgap with high reflectivity to generate high-purity orange and yellow colors. In particular, we demonstrate an A-DBR with a large photonic bandgap tunability by changing the structural phase of Sb2S3 layers from amorphous to crystalline. Moreover, we experimentally tailor multistate tunable colors through external optical stimuli. Unlike conventional nano thin-film coatings, our proposed approach offers an irradiance-free, narrowband, and highly reflective color band, achieving exceptional color purity by effectively suppressing reflections in off-color bands.
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Dominance of neotropical tree communities by a few species is widely documented, but dominant trees show a variety of distributional patterns still poorly understood. Here, we used 503 forest inventory plots (93,719 individuals ≥2.5 cm diameter, 2609 species) to explore the relationships between local abundance, regional frequency and spatial aggregation of dominant species in four main habitat types in western Amazonia. Although the abundance-occupancy relationship is positive for the full dataset, we found that among dominant Amazonian tree species, there is a strong negative relationship between local abundance and regional frequency and/or spatial aggregation across habitat types. Our findings suggest an ecological trade-off whereby dominant species can be locally abundant (local dominants) or regionally widespread (widespread dominants), but rarely both (oligarchs). Given the importance of dominant species as drivers of diversity and ecosystem functioning, unravelling different dominance patterns is a research priority to direct conservation efforts in Amazonian forests.
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Ecossistema , Florestas , Humanos , Árvores , Brasil , BiodiversidadeRESUMO
MAIN CONCLUSION: Natural selection influenced adaptive divergence between Cereus fernambucensis and Cereus insularis, revealing key genes governing abiotic stress responses and supporting neoteny in C. insularis. Uncovering the molecular mechanisms driving adaptive divergence in traits related to habitat adaptation remains a central challenge. In this study, we focused on the cactus clade, which includes Cereus sericifer F.Ritter, Cereus fernambucensis Lem., and Cereus insularis Hemsley. These allopatric species inhabit distinct relatively drier regions within the Brazilian Atlantic Forest, each facing unique abiotic conditions. We leveraged whole transcriptome data and abiotic variables datasets to explore lineage-specific and environment-specific adaptations in these species. Employing comparative phylogenetic methods, we identified genes under positive selection (PSG) and examined their association with non-synonymous genetic variants and abiotic attributes through a PhyloGWAS approach. Our analysis unveiled signatures of selection in all studied lineages, with C. fernambucensis northern populations and C. insularis showing the most PSGs. These PSGs predominantly govern abiotic stress regulation, encompassing heat tolerance, UV stress response, and soil salinity adaptation. Our exclusive observation of gene expression tied to early developmental stages in C. insularis supports the hypothesis of neoteny in this species. We also identified genes associated with abiotic variables in independent lineages, suggesting their role as environmental filters on genetic diversity. Overall, our findings suggest that natural selection played a pivotal role in the geographic range of these species in response to environmental and biogeographic transitions.
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Adaptação Fisiológica , Cactaceae , Florestas , Perfilação da Expressão Gênica , Filogenia , Brasil , Cactaceae/genética , Cactaceae/fisiologia , Adaptação Fisiológica/genética , Seleção Genética , Transcriptoma , Estresse Fisiológico/genética , Regulação da Expressão Gênica de PlantasRESUMO
Urbanization alters natural habitats, restructures biotic communities and serves as a filter for selecting species from regional species pools. However, empirical evidence of the specific traits that allow species to persist in urban areas yields mixed results. More importantly, it remains unclear which traits are widespread for species utilizing urban spaces (urban utilizers) and which are environment-dependent traits. Using 745 bird species from 287 university/institute campuses in 74 cities and their species pools across China, we tested whether species that occur in urban areas are correlated with regards to their biological (body mass, beak shape, flight capacity and clutch size), ecological (diet diversity, niche width and habitat breadth), behavioural (foraging innovation) and evolutionary (diversification rate) attributes. We used Bayesian phylogenetic generalized linear mixed models to disentangle the relative roles of these predictors further, and to determine the extent to which the effects of these predictors varied among different cities. We found that urban birds were more phylogenetically clustered than expected by chance, and were generally characterized by a larger habitat breadth, faster diversification rate, more behavioural innovation and smaller body size. Notably, the relative effects of the attributes in explaining urban bird communities varied with city temperature and elevation, indicating that the filters used to determine urban species were environment dependent. We conclude that, while urban birds are typically small-sized, generalists, innovative and rapidly diversifying, the key traits that allow them to thrive vary spatially, depending on the climatic and topographic conditions of the city. These findings emphasize the importance of studying species communities within specific cities to better understand the contextual dependencies of key traits that are filtered by urban environments.
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Aves , Ecossistema , Animais , Teorema de Bayes , Biodiversidade , Cidades , Filogenia , Universidades , UrbanizaçãoRESUMO
BACKGROUND AND OBJECTIVES: This study evaluated the utilization and outcomes of inferior vena cava (IVC) filters as thromboprophylaxis in cancer patients undergoing surgery. METHODS: This single-center retrospective study analyzed baseline patient characteristics and clinical outcomes of surgical cancer patients who received perioperative prophylactic IVC filters. Primary clinical endpoints included venous thromboembolism (VTE) incidence and filter complications. A statistical correlative analysis was conducted to identify risk factors related to pulmonary embolism (PE), deep vein thrombosis (DVT), and filter thrombi, as well as advanced technique filter removal and mortality at 6 months. RESULTS: A total of 252 surgical oncology patients (median age, 59; female 51%) received IVC filters for the perioperative prevention of PE. Primary surgical sites included spine (n = 91, 36%), orthopedic extremity/joint (n = 49, 19%), genitourinary (n = 47, 19%), brain/cranial (n = 40, 16%), abdominal (n = 18, 7%), multisite (n = 4, 2%), and chest (n = 3, 1%). Moreover, 15% of patients experienced DVTs in the postplacement preretrieval period, while 2% (n = 6) of patients experienced definitive PEs. A total of 36% of IVC filters were ultimately retrieved, with an average filter dwell time of 7.4 months. Complications occurred in one retrieval. CONCLUSION: Prophylactic perioperative IVC filters in surgical cancer patients resulted in minimal complications while ultimately resulting in a low incidence of PE.
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Neoplasias , Embolia Pulmonar , Filtros de Veia Cava , Tromboembolia Venosa , Humanos , Feminino , Masculino , Neoplasias/cirurgia , Neoplasias/complicações , Estudos Retrospectivos , Pessoa de Meia-Idade , Tromboembolia Venosa/prevenção & controle , Tromboembolia Venosa/etiologia , Idoso , Embolia Pulmonar/prevenção & controle , Embolia Pulmonar/etiologia , Embolia Pulmonar/epidemiologia , Adulto , Trombose Venosa/prevenção & controle , Trombose Venosa/etiologia , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/epidemiologia , Idoso de 80 Anos ou mais , Fatores de RiscoRESUMO
Plasmonic spectral filters composed of periodic nanostructured metal films offer novel opportunities for the development of multispectral imaging technologies in the mid-infrared region. However, traditional plasmonic filters, which typically feature simplistic structures such as nanoholes or nanorings, are constrained by a narrow bandpass and significant crosstalk, leading to limited practical performance. Filters designed using inverse techniques allow a substantial degree of freedom in creating intricate structures that align with desired spectral characteristics, including a quasi-square spectral profile, high transmission, wide full width at half maximum, and reduced crosstalk. In this study, we have utilized an inverse design algorithm to engineer high-performance bandpass filters for the mid-infrared range, achieving an average transmittance exceeding 80% within the bandpass window and below 10% in the stop band, which is comparable to that of commercial multilayer Bragg filters. Nanofabrication processes were employed to transfer the designed pattern into the gold film on ZnS substrate that is transparent in the mid-infrared range. The resulting filters exhibit spectral performance analogous to that of the inversely designed models, making them suitable for direct integration with mid-infrared photodetector arrays in multispectral imaging systems.
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AIMS: Monitoring current of injury (COI) during left bundle branch area pacing (LBBAP) implantation is useful to evaluate lead depth. Technical aspects for recording COI amplitude have not been well studied. Our aims were to evaluate the impact of high-pass filter settings on electrogram recordings during LBBAP implantation. METHODS AND RESULTS: Consecutive patients with successful LBBAP implantation had unipolar recordings of COI at final lead position at different high-pass filter settings (0.01-1â Hz) from the tip electrode during sensing and pacing, and from the ring electrode during sensing. Duration of saturation-induced signal loss was also measured at each filter setting. COI amplitudes were compared between lumenless and stylet-driven leads. A total of 156 patients (96 males, aged 81.4 ± 9.6 years) were included. Higher filter settings led to significantly lower COI amplitudes. In 50 patients with COI amplitude < 10â mV, the magnitude of the drop was on average 1-1.5â mV (and up to 4â mV) between 0.05 and 0.5â Hz, meaning that cut-offs may not be used interchangeably. Saturation-induced signal loss was on average 10â s at 0.05â Hz and only 2â s with 0.5â Hz. When pacing was interrupted, the sensed COI amplitude varied (either higher or lower) by up to 4â mV, implying that it is advisable to periodically interrupt pacing to evaluate the sensed COI when reaching levels of â¼10â mV. Lead type did not impact COI amplitude. CONCLUSION: High-pass filters have a significant impact on electrogram characteristics at LBBAP implantation, with the 0.5â Hz settings having the most favourable profile.
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Estimulação Cardíaca Artificial , Humanos , Masculino , Feminino , Idoso de 80 Anos ou mais , Idoso , Estimulação Cardíaca Artificial/métodos , Eletrodos Implantados , Técnicas Eletrofisiológicas Cardíacas , Fascículo Atrioventricular/fisiopatologia , Marca-Passo Artificial , Desenho de Equipamento , Resultado do Tratamento , Potenciais de AçãoRESUMO
BACKGROUND: The placement of inferior vena cava (IVC) filters often emerges as an alternative preventative measure against pulmonary embolism in patients with upper gastrointestinal (GI) bleeding and isolated distal deep vein thrombosis (DVT). We aimed to investigate the association of IVC filter placement and the incidence of venous thromboembolism (VTE) recurrence in this patient population. METHODS: We performed a retrospective cohort study including 450 patients with upper GI bleeding and isolated distal DVT. Propensity score matching using logistic regression was conducted to mitigate potential selection bias. Logistic regression models and additional sensitivity analyses were conducted to estimate the association between IVC filter implantation and VTE recurrence. Interaction and stratified analyses were also performed according to the background covariates. RESULTS: Patients who underwent IVC filter placement were significantly younger than patients in the surveillance group (55.8 ± 9.0 vs 58.4 ± 11.2 years, p = 0.034). Patients in the IVC filter group demonstrated a higher distal thrombus burden. The VTE recurrence composite was significantly higher in patients who underwent IVC filter placement (44.1% [45/102] vs 25% [87/348], p < 0.001). Unmatched crude logistic regression analysis identified a significant association between IVC filter placement and VTE recurrence composite (OR = 2.37; 95% CI, 1.50-3.75). Sensitivity analyses yielded congruent outcomes. CONCLUSION: This study revealed an increased risk of VTE recurrence among patients receiving IVC filter placement, suggesting that IVC filter placement may not be suitable as a primary treatment for patients with upper GI bleeding and isolated distal DVT.
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Hemorragia Gastrointestinal , Recidiva , Filtros de Veia Cava , Tromboembolia Venosa , Trombose Venosa , Humanos , Filtros de Veia Cava/efeitos adversos , Estudos Retrospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Hemorragia Gastrointestinal/etiologia , Hemorragia Gastrointestinal/epidemiologia , Hemorragia Gastrointestinal/diagnóstico , Hemorragia Gastrointestinal/terapia , Trombose Venosa/diagnóstico , Trombose Venosa/epidemiologia , Trombose Venosa/etiologia , Trombose Venosa/terapia , Fatores de Risco , Idoso , Resultado do Tratamento , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/epidemiologia , Tromboembolia Venosa/prevenção & controle , Tromboembolia Venosa/etiologia , Medição de Risco , Adulto , Incidência , Implantação de Prótese/efeitos adversos , Implantação de Prótese/instrumentação , Fatores de TempoRESUMO
As our knowledge of the harmful effects of ultraviolet radiation continues to evolve, sunscreen remains an integral part of a comprehensive photoprotection strategy against multiple endpoints of ultraviolet-mediated damage. Part 1 of this review covers sunscreen active and additive ingredient properties, mechanisms of action and gaps in coverage. Following an overview of sunscreen's efficacy in protecting against sunburn, photocarcinogenesis, photoaging, pigmentary disorders, and idiopathic photodermatoses, we highlight considerations for product use and selection in children and individuals with skin of color.
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The second part of this CME article discusses sunscreen regulation and safety considerations for humans and the environment. First, we provide an overview of the history of the United States Food and Drug Administration's regulation of sunscreen. Recent Food and Drug Administration studies clearly demonstrate that organic ultraviolet filters are systemically absorbed during routine sunscreen use, but to date there is no evidence of associated negative health effects. We also review the current evidence of sunscreen's association with vitamin D levels and frontal fibrosing alopecia, and recent concerns regarding benzene contamination. Finally, we review the possible environmental effects of ultraviolet filters, particularly coral bleaching. While climate change has been shown to be the primary driver of coral bleaching, laboratory-based studies suggest that organic ultraviolet filters represent an additional contributing factor, which led several localities to ban certain organic filters.
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Is there a "missing device" for respiratory personal protection? Does it exist an easy-to-use device, allowing extensive use in everyday settings by the population, maximizing tolerability and low visual and physical invasiveness protecting from a wide range of threats including airborne pathogens, hence including the particle range of fine and ultrafine particles? Looking at the recent past, in the urgency of finding ready-to-use solutions for the respiratory protection of the population during the outbreak of the SARS-CoV-2 pandemic, devices for occupational safety have been used, such as filtering face masks. These are devices intended for workers operating during work shifts in environments characterized by potential high risk, known a priori, often directly sensible; this makes wearers motivated to tolerate discomfort for a given period to face a localized risk, and safety managers determined to supervise compliance with usage specifications. Their use by general population has implied known shortcomings, such as weak compatibility with relational work and activities, low tolerability during prolonged use, low compliance with the proper use of the device, all of this lessening actual protection. The need for a new perspective has emerged, targeting effectiveness in whole daily life, rather than punctual efficacy. Nasal filters are promising candidates to protect individuals throughout the day during the most varied activities, but they lack a systematic definition as a device and as a product; it follows that the high complexity needed to reach an effective performance envelop is generally underestimated. By reviewing available literature, the present paper draws on the experience from the pandemic and infers systematic product specifications and characterization methods for a new, effective personal respiratory protection device; these specifications are compared with the stringent constraints associated with the endonasal applications and, based on air filtration state of the art, quantifies the need for technology disruption and outlining possible new development paths.
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COVID-19 , Filtração , Pandemias , SARS-CoV-2 , COVID-19/prevenção & controle , COVID-19/epidemiologia , Humanos , Pandemias/prevenção & controle , Filtração/instrumentação , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/prevenção & controle , Pneumonia Viral/epidemiologia , Betacoronavirus , Dispositivos de Proteção Respiratória , Filtros de Ar , Exposição Ocupacional/prevenção & controle , MáscarasRESUMO
The ecological risks of organic ultraviolet absorbents (UVAs) have been of increasing concern. Studies have found that these chemicals could be accumulated in terrestrial animals and pose toxicities. However, tissue distribution of UVAs in terrestrial species was far from well understood. In this study, free-range chickens and domestic pigeons were selected to investigate the occurrence and tissue distribution of UVAs. Total concentrations of eleven UVAs in muscles ranged from 778 to 2874 (mean 1413 ± 666) ng/g lipid weight, which were higher than those in aquatic species worldwide. Since low UVA concentrations in local environment were previously reported, the results implied the strong accumulation of UVAs in studied species. Brain, stomach and kidney were main target organs for studied UVAs, differentiating from the strong liver sequestration in aquatic species. The mean tissue-to-muscle ratios of 1.02-4.23 further indicated the preferential accumulation of target UVAs in these tissues. The tissue-to-blood ratios of benzophenone (BP), 2-ethylhexyl salicylate (EHS) and homosalate (HMS) in brain were 370, 1207 and 52.0, respectively, implying their preferential accumulation in brain. More research is needed to characterize the toxicokinetics and tissue distribution of UVAs in terrestrial wild species, in order to further understand their potential risks.
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Peixes , Poluentes Químicos da Água , Animais , Columbidae , Galinhas , Distribuição Tecidual , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , ChinaRESUMO
Although filtration is one of the most common steps in sample preparation for chemical analysis, filter membrane materials can leach contaminants and/or retain some analytes in the filtered solutions. In multiclass, multiresidue analysis of veterinary drugs, it is challenging to find one type of filter membrane that does not retain at least some of the analytes before injection in ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). In this study, different filter membranes were tested for use in UHPLC-MS/MS analysis of 183 diverse drugs in bovine muscle, kidney, and liver tissues. Membranes evaluated consisted of polytetrafluoroethylene (PTFE), polyvinylidene difluoride (PVDF), polyethersulfone, nylon, and regenerated cellulose. Drug classes represented among the analytes included ß-agonists, ß-lactams, anthelmintics, macrolides, tetracyclines, sulfonamides, tranquilizers, (fluoro)quinolones, anti-inflammatories, nitroimidazoles, coccidiostats, phenicols, and others. Although the presence of a matrix helped reduce the binding of analytes on surface active sites, all of the filter types partially retained at least some of the drugs in the final extracts. In testing by flow-injection analysis, all of the membrane filters were also observed to leach interfering components. Ultimately, filtration was avoided altogether in the final sample preparation approach known as the quick, easy, cheap, effective, rugged, safe, efficient, and robust (QuEChERSER) mega-method, and ultracentrifugation was chosen as an alternative.
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Resíduos de Drogas , Drogas Veterinárias , Animais , Bovinos , Espectrometria de Massas em Tandem/métodos , Cromatografia Gasosa-Espectrometria de Massas , Cromatografia Líquida , Cromatografia Líquida de Alta Pressão/métodos , Antibacterianos/análise , Drogas Veterinárias/análise , Resíduos de Drogas/análiseRESUMO
Bayesian learning theory and evolutionary theory both formalize adaptive competition dynamics in possibly high-dimensional, varying, and noisy environments. What do they have in common and how do they differ? In this paper, we discuss structural and dynamical analogies and their limits, both at a computational and an algorithmic-mechanical level. We point out mathematical equivalences between their basic dynamical equations, generalizing the isomorphism between Bayesian update and replicator dynamics. We discuss how these mechanisms provide analogous answers to the challenge of adapting to stochastically changing environments at multiple timescales. We elucidate an algorithmic equivalence between a sampling approximation, particle filters, and the Wright-Fisher model of population genetics. These equivalences suggest that the frequency distribution of types in replicator populations optimally encodes regularities of a stochastic environment to predict future environments, without invoking the known mechanisms of multilevel selection and evolvability. A unified view of the theories of learning and evolution comes in sight.
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Evolução Biológica , Genética Populacional , Teorema de Bayes , AprendizagemRESUMO
The use of topical photoprotection is necessary to reduce adverse effects caused by excessive exposure to ultraviolet radiation. Despite the high standards set for UV filters, many of them may contribute to the occurrence of adverse effects. The newly synthesised compound K-116, the (E)-cinnamoyl xanthone derivative, could be an alternative. We conducted extended in vitro safety evaluation of compound K-116. The research included assessment of irritation potential on skin tissue, evaluation of penetration through the epidermis, and assessment of phototoxicity, and mutagenicity. Additionally, the eco-safety of compound K-116 was evaluated, including an examination of its degradation pathway in the Cunninghamella echinulata model, as well as in silico simulation of the toxicity of both the parent compound and its degradation products. The research showed that compound K-116 tested in future application conditions is deprived of skin irritant potential additionally it does not penetrate through the epidermis. Results showed that K-116 concentrate is not phototoxic and not mutagenic. The eco-safety studies showed that it undergoes biodegradation in 27% in Cunninghamella echinulata model. The parent compound and formed metabolite are less toxic than reference UV filters (octinoxate and octocrylene).
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Acrilatos , Protetores Solares , Raios Ultravioleta , Protetores Solares/toxicidade , Pele/efeitos dos fármacos , Pele/metabolismo , Humanos , Testes de Mutagenicidade , AnimaisRESUMO
The increasing use of UV filters, such as benzophenone-3 (BP-3) and titanium dioxide nanoparticles (TiO2 NPs), has raised concerns regarding their ecotoxicological effects on the aquatic environment. The aim of the present study was to examine the embryo-larval toxicity attributed to BP-3 or TiO2 NPs, either alone or in a mixture, utilizing zebrafish (Danio rerio) as a model after exposure to environmentally relevant concentrations of these compounds. Zebrafish embryos were exposed to BP-3 (10, 100, or 1000 ng/L) or TiO2 NPs (1000 ng/L) alone or in a mixture (BP-3 10, 100, or 1000 ng/L plus 1000 ng/L of TiO2 NPs) under static conditions for 144 hr. After exposure, BP-3 levels were determined by high-performance liquid chromatography (HPLC). BP-3 levels increased in the presence of TiO2 NPs, indicating that the BP-3 degradation decreased in the presence of the NPs. In addition, in the presence of zebrafish, BP-3 levels in water decreased, indicating that zebrafish embryos and larvae might absorb BP-3. Data demonstrated that, in general, environmentally relevant concentrations of BP-3 and TiO2 NPs, either alone or in a mixture, did not significantly induce changes in heart and spontaneous contractions frequencies, levels of reactive oxygen species (ROS), morphological and morphometric parameters as well as mortality rates during 144 hr exposure. However, the groups exposed to TiO2 NPs alone and in a mixture with BP-3 at 10 ng/L exhibited an earlier significant hatching rate than the controls. Altogether, the data indicates that a potential ecotoxicological impact on the aquatic environment exists.