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The fossil collections made by early explorers in South America have been fundamental to reveal the past diversity of extinct mammals and unravel their evolutionary history. One important early explorer in South America was the Swiss-Argentine palaeontologist Kaspar Jacob Roth, known as Santiago Roth (1850, Herisau, Switzerland-1924, Buenos Aires, Argentina), who made significant collections of fossil mammals that are housed in museums in Europe and Argentina. The important collections of Roth in Switzerland include iconic Pleistocene megafauna from the Pampean Region (Argentina). The palaeontological significance of the Pampean Region relies on its abundant record of fossil vertebrates that documents diversity dynamics and paleoenvironmental change in southern South America, serving as the basis for the South American biostratigraphical scale of the late Neogene and Quaternary. The South American native ungulates (SANUs) were hoofed placental mammals that radiated in South America. The clades Notoungulata and Litopterna include, among others, the last representatives of SANUs megafauna in the continent. We revise and describe for the first time the SANUs specimens from the Pampean Region of the Roth collections in Switzerland. The collections include two species of notoungulates (Toxodon cf. T. platensis and Mesotherium cristatum) and one litoptern species (Macrauchenia patachonica). The occurrences are restricted to the early and middle Pleistocene (pre-Lujanian Stages/Ages). Although the SANUs diversity in the Roth collections is low in comparison with other groups (e.g., xenarthrans), some of the specimens are very complete, including skulls and postcranial remains. The completeness of the Ma. patachonica material allows an update and reinterpretation of some of the details of the dentition and the postcranial skeleton of this iconic species. In addition to its historical importance, the SANU specimens from the Roth collections provide important information to study the paleobiology and evolution of South American megafauna and evaluate hypotheses about their extinction in the continent.
Las colecciones de fósiles realizadas por los primeros exploradores en América del Sur han sido fundamentales para revelar la diversidad pasada de los mamíferos sudamericanos y desentrañar su historia evolutiva. Un importante explorador en América del Sur fue el paleontólogo suizo-argentino Kaspar Jacob Roth, conocido como Santiago Roth (1850, Herisau, Suiza-1924, Buenos Aires, Argentina), quien realizó importantes colecciones de mamíferos fósiles que se encuentran en museos de Europa y Argentina. Las colecciones de Roth en Suiza incluyen la icónica megafauna del Pleistoceno de la Región Pampeana (Argentina). La importancia paleontológica de la Región Pampeana se basa en su abundante registro de vertebrados fósiles que documenta la diversidad y el cambio paleoambiental en el sur de Sudamérica, sirviendo como base para la escala bioestratigráfica sudamericana del Neógeno tardío y Cuaternario. Los ungulados nativos sudamericanos (SANUs, por sus siglas en inglés) eran mamíferos placentarios con pezuñas que radiaron en Sudamérica. Los clados Notoungulata y Litopterna incluyen, entre otros, los últimos representantes de la megafauna de SANUs en el continente. En este trabajo, revisamos y describimos por primera vez los SANUs de la Región Pampeana de las colecciónes de Roth en Suiza. Las colecciónes incluyen dos especies de notungulados (Toxodon cf. T. platensis y Mesotherium cristatum) y una especie de litopterna (Macrauchenia patachonica). Las ocurrencias están restringidas al Pleistoceno temprano y medio (Pisos/Edades anteriores al Lujanense). Aunque la diversidad de SANU en las colecciónes Roth es baja en comparación con otros grupos (por ejemplo, xenarthros), algunos de los especímenes son muy completos, e incluyen cráneos y restos poscraneales. Lo completo del material de Ma. patachonica permite una actualización y reinterpretación de algunos de los detalles de la dentición y el esqueleto poscraneal de esta icónica especie. Además de su importancia histórica, los SANUs de la colección Roth brindan información importante para estudiar la paleobiología y evolución de la megafauna sudamericana y evaluar hipótesis sobre su extinción en el continente.
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PURPOSE: Although the initial description of the distal biceps tendon (DBT) hook test (HT) reported 100% sensitivity (Sn) and specificity (Sp), subsequent retrospective series have demonstrated imperfect validity. The purpose of this investigation was to prospectively assess the validity and reliability of the HT for complete DBT ruptures. We aimed to determine the Sn/Sp and interrater reliability for the HT. METHODS: A consecutive series of adult patients presenting to our outpatient clinics with an elbow complaint was prospectively examined. Patients were included if they had undergone advanced imaging (magnetic resonance imaging or ultrasound) that imaged the DBT and underwent DBT repair. There were four participating surgeons, all of whom were blinded to magnetic resonance imaging/ultrasound prior to performing the HT. To determine the Sn/Sp of the HT and advanced imaging, intraoperative findings served as the primary reference standard. The interrater reliability of the HT was calculated for cases in which a primary examiner (surgeon) and secondary examiner (physician assistant or resident) performed the HT. RESULTS: Of 64 patients who had undergone advanced imaging, 28 (44%) underwent DBT surgery and were included in the assessment of Sn/Sp. The mean age was 49 years, and all patients were men. The Sn and Sp of the HT were 96% and 67%, respectively. Advanced imaging demonstrated 100% Sn and Sp. Twenty-five patients were evaluated by a primary and secondary examiner. The interrater reliability was substantial (Cohen kappa, 0.71). CONCLUSIONS: The Sn and Sp of the HT were 96% and 67%, respectively, when assessed prospectively. Advanced imaging findings (magnetic resonance imaging/ultrasound) demonstrated 100% Sn and Sp. The HT can be performed reliably by examiners with varying experience levels. Considering the imperfect validity of the HT, we caution against the use of this examination alone to diagnose DBT ruptures. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.
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Cotovelo , Traumatismos dos Tendões , Adulto , Masculino , Humanos , Pessoa de Meia-Idade , Feminino , Estudos Retrospectivos , Reprodutibilidade dos Testes , Traumatismos dos Tendões/diagnóstico por imagem , Traumatismos dos Tendões/cirurgia , Tendões , Ruptura/diagnóstico por imagem , Ruptura/cirurgiaRESUMO
In the dusk of the Mesozoic, advanced duck-billed dinosaurs (Hadrosauridae) were so successful that they likely outcompeted other herbivores, contributing to declines in dinosaur diversity. From Laurasia, hadrosaurids dispersed widely, colonizing Africa, South America, and, allegedly, Antarctica. Here, we present the first species of a duck-billed dinosaur from a subantarctic region, Gonkoken nanoi, of early Maastrichtian age in Magallanes, Chile. Unlike duckbills further north in Patagonia, Gonkoken descends from North American forms diverging shortly before the origin of Hadrosauridae. However, at the time, non-hadrosaurids in North America had become replaced by hadrosaurids. We propose that the ancestors of Gonkoken arrived earlier in South America and reached further south, into regions where hadrosaurids never arrived: All alleged subantarctic and Antarctic remains of hadrosaurids could belong to non-hadrosaurid duckbills like Gonkoken. Dinosaur faunas of the world underwent qualitatively different changes before the Cretaceous-Paleogene asteroid impact, which should be considered when discussing their possible vulnerability.
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Dinossauros , Animais , Dinossauros/anatomia & histologia , Fósseis , Patos , Chile , América do NorteRESUMO
Purpose: As many as one-third of patients with heart failure secondary to systemic, wild-type transthyretin amyloidosis have an associated distal biceps tendon (DBT) rupture. Our purpose was to identify the prevalence of amyloid deposition in patients undergoing operative repair of acute traumatic DBT ruptures. Methods: In this prospective investigation, a consecutive series of patients who underwent repair of an acute traumatic DBT rupture underwent a tendon biopsy to assess for amyloid deposition. All specimens were viewed under gross microscopy by a board-certified pathologist. For initial screening, either Congo red or Thioflavin-T immunohistochemistry analysis was conducted to determine amyloid status. If staining was positive for amyloid deposition using either technique, the tissue sample was sent to an outside facility for specific amyloid protein identification through liquid chromatography-tandem mass spectrometry. Baseline demographics were also recorded for each patient. Results: A total of 30 patients who underwent biopsy and repair of an acute DBT rupture were included. The mean age was 48 years, and all patients were men. Seven (23%) patients had a history of carpal tunnel syndrome, and 1 (3%) patient had evidence of heart failure at the time of surgery. One (3%) patient had evidence of amyloid deposition in the DBT, which was confirmed using liquid chromatography-tandem mass spectrometry. Conclusions: Although one-third of patients with heart failure secondary to cardiac amyloidosis have an associated DBT rupture, younger patients with acute traumatic DBT ruptures do not appear to be uniquely at risk for amyloid deposition at the time of DBT repair. Larger registry studies may be necessary to define the risk of developing cardiac amyloidosis years after sustaining an acute DBT rupture. Type of study/level of evidence: Prognostic IV.
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OBJECTIVE: Early life trauma (ELT) and HIV are associated with social processing deficits. In people with HIV (PWH), we examined whether facial emotion identification accuracy differs by ELT and whether neuroendocrine factors including cortisol, oxytocin (OT), and arginine vasopressin, and/or immune system measures play a role in the ELT-performance association. METHODS: We used secondary data from the placebo condition of a pharmacologic challenge study in PWH. Presence of ELT was measured with the Childhood Trauma Questionnaire (at least moderate experiences of sexual, physical, and/or emotional abuse). Social processing was measured with the Facial Emotion Perception Test (FEPT). Salivary immune system measures and cortisol were sampled across a 5-hour study session. Blood was collected at study session start (12 pm ) to measure OT and arginine vasopressin. We examined the association of ELT with FEPT and five biological moderators (from principal components analysis of 12 biomarkers) of ELT-FEPT associations. RESULTS: Of 58 PWH (42 men; mean [standard deviation] age = 33.7 [8.9] years), 50% endorsed ELT. ELT-exposed PWH demonstrated lower identification accuracy across all emotional expressions (unstandardized ß [ B ] = 0.13; standard error [SE] = 0.05; p = .021, d = 0.63) and had higher OT levels compared with ELT-unexposed PWH ( t(1,56) = 2.12, p = .039; d = 0.57). For total accuracy, an OT/C-reactive protein factor moderated the ELT-FEPT association ( B = 0.14; SE = 0.05; p = .014); accuracy was lower in ELT-exposed PWH versus ELT-unexposed PWH when the factor was low but not when high. Similar results were obtained for fearful, neutral, and happy faces ( p values < .05). Regardless of ELT, a myeloid migration (MCP-1/MMP-9) factor was associated with reduced accuracy ( p values < .05). CONCLUSIONS: Our pilot findings suggest that ELT may alter social processing in PWH, and OT and C-reactive protein may be a target for improving social processing in ELT-exposed PWH, and myeloid migration markers may be a target in PWH more generally.
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Infecções por HIV , Ocitocina , Adulto , Arginina Vasopressina , Proteína C-Reativa , Feminino , Infecções por HIV/complicações , Humanos , Hidrocortisona , Inflamação , Masculino , Metaloproteinase 9 da Matriz , Percepção SocialRESUMO
T follicular helper (Tfh) cells are required to develop germinal center (GC) responses and drive immunoglobulin class switch, affinity maturation, and long-term B cell memory. In this study, we characterize a recently developed vaccine platform, nucleoside-modified, purified mRNA encapsulated in lipid nanoparticles (mRNA-LNPs), that induces high levels of Tfh and GC B cells. Intradermal vaccination with nucleoside-modified mRNA-LNPs encoding various viral surface antigens elicited polyfunctional, antigen-specific, CD4+ T cell responses and potent neutralizing antibody responses in mice and nonhuman primates. Importantly, the strong antigen-specific Tfh cell response and high numbers of GC B cells and plasma cells were associated with long-lived and high-affinity neutralizing antibodies and durable protection. Comparative studies demonstrated that nucleoside-modified mRNA-LNP vaccines outperformed adjuvanted protein and inactivated virus vaccines and pathogen infection. The incorporation of noninflammatory, modified nucleosides in the mRNA is required for the production of large amounts of antigen and for robust immune responses.
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Linfócitos B/imunologia , Centro Germinativo/citologia , Nucleosídeos/metabolismo , RNA Mensageiro/metabolismo , Linfócitos T Auxiliares-Indutores/imunologia , Vacinas de Subunidades Antigênicas/imunologia , Adjuvantes Imunológicos/farmacologia , Animais , Anticorpos Neutralizantes/imunologia , Formação de Anticorpos/imunologia , Antígenos/metabolismo , Lipídeos/química , Macaca mulatta , Nanopartículas/química , Subunidades Proteicas/metabolismo , Fatores de Tempo , VacinaçãoRESUMO
In order to map scientists' views on media channels and explore their experiences interacting with journalists, the authors conducted a survey of about 1,000 Brazilian scientists. Results indicate that scientists have clear and high expectations about how journalists should act in reporting scientific information in the media, but such expectations, in their opinion, do not always seem to be met. Nonetheless, the results show that surveyed scientists rate their relation with the media positively: 67% say that having their research covered by media has a positive impact on their colleagues. One quarter of the respondents expressed that talking to the media can facilitate acquisition of more funds for research. Moreover, 38% of the total respondents believe that writing about an interesting topic for release on media channels can also facilitate research publication in a scientific journal. However, 15% of the respondents outright agree that research reported in the media beforehand can threaten acceptance for publication by a scientific journal. We hope that these results can foster some initiatives for improving awareness of the two cultures, scientists and journalists; increasing the access of journalists to Brazilian scientific endeavors; stimulating scientists to communicate with the public via social networks.
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Pesquisa Biomédica , Apoio Financeiro , Relações Interprofissionais , Meios de Comunicação de Massa , Editoração , Brasil , Humanos , Inquéritos e QuestionáriosRESUMO
STUDY OBJECTIVES: Sleep rebound-the increase in sleep that follows sleep deprivation-is a hallmark of homeostatic sleep regulation that is conserved across the animal kingdom. However, both the mechanisms that underlie sleep rebound and its relationship to habitual daily sleep remain unclear. To address this, we developed an efficient thermogenetic method of inducing sleep deprivation in Drosophila that produces a substantial rebound, and applied the newly developed method to assess sleep rebound in a screen of 1,741 mutated lines. We used data generated by this screen to identify lines with reduced sleep rebound following thermogenetic sleep deprivation, and to probe the relationship between habitual sleep amount and sleep following thermogenetic sleep deprivation in Drosophila. METHODS: To develop a thermogenetic method of sleep deprivation suitable for screening, we thermogenetically stimulated different populations of wake-promoting neurons labeled by Gal4 drivers. Sleep rebound following thermogenetically-induced wakefulness varies across the different sets of wake-promoting neurons that were stimulated, from very little to quite substantial. Thermogenetic activation of neurons marked by the c584-Gal4 driver produces both strong sleep loss and a substantial rebound that is more consistent within genotypes than rebound following mechanical or caffeine-induced sleep deprivation. We therefore used this driver to induce sleep deprivation in a screen of 1,741 mutagenized lines generated by the Drosophila Gene Disruption Project. Flies were subjected to 9 h of sleep deprivation during the dark period and released from sleep deprivation 3 h before lights-on. Recovery was measured over the 15 h following sleep deprivation. Following identification of lines with reduced sleep rebound, we characterized baseline sleep and sleep depth before and after sleep deprivation for these hits. RESULTS: We identified two lines that consistently exhibit a blunted increase in the duration and depth of sleep after thermogenetic sleep deprivation. Neither of the two genotypes has reduced total baseline sleep. Statistical analysis across all screened lines shows that genotype is a strong predictor of recovery sleep, independent from effects of genotype on baseline sleep. CONCLUSIONS: Our data show that rebound sleep following thermogenetic sleep deprivation can be genetically separated from sleep at baseline. This suggests that genetically controlled mechanisms of sleep regulation not manifest under undisturbed conditions contribute to sleep rebound following thermogenetic sleep deprivation.
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Drosophila melanogaster/genética , Drosophila melanogaster/fisiologia , Homeostase/genética , Homeostase/fisiologia , Privação do Sono/genética , Privação do Sono/fisiopatologia , Sono/genética , Sono/fisiologia , Animais , Feminino , Genótipo , Modelos Animais , Mutação , Neurônios/fisiologia , Temperatura , Fatores de Tempo , Vigília/genética , Vigília/fisiologiaRESUMO
BACKGROUND AND AIM: Fasting is an important risk factor for hypoglycemia in children with malaria or pneumonia. Young children are more at risk because of impaired endogenous glucose production presumably due to smaller liver glycogen stores. The aim of this study was to measure the effect of a bolus of glucagon on glucose kinetics, as an indicator of glycogen content, in fasted children with malaria and pneumonia. METHODS: After a 16-h controlled fast, plasma glucose concentration and endogenous glucose production were measured using [6,6-2H2]glucose in six children with severe malaria and 12 children with severe pneumonia who were 1-5 years of age before and after a bolus glucagon. RESULTS: Basal glucose concentration and endogenous glucose production were higher in children with malaria, p=0.034 and p=0.010, respectively. After glucagon, the increase in the plasma glucose concentration was higher in children with malaria (52±26% vs. 31±23%, p=0.029). Also, the increase in glucose production was higher in children with malaria (106±42% vs. 70±52%, p=0.023). There were no differences in the fasting duration or duration of illness. CONCLUSIONS: This is the first study to show infectious disease-related differences in the adaptation of glucose metabolism to fasting in young children. It was found that basal glucose concentration and endogenous glucose production were higher in children with malaria. The increase in plasma glucose concentration and endogenous glucose production in response to glucagon was higher in children with malaria, indicating smaller glycogen stores in children with pneumonia.
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Glicemia/metabolismo , Glicogênio/metabolismo , Hipoglicemia/metabolismo , Fígado/metabolismo , Malária/metabolismo , Pneumonia/metabolismo , Adaptação Fisiológica/fisiologia , Glicemia/efeitos dos fármacos , Pré-Escolar , Jejum/fisiologia , Feminino , Fármacos Gastrointestinais/administração & dosagem , Glucagon/administração & dosagem , Humanos , Hipoglicemia/epidemiologia , Lactente , Insulina/sangue , Malária/epidemiologia , Masculino , Modelos Biológicos , Projetos Piloto , Pneumonia/epidemiologia , Fatores de Risco , SurinameRESUMO
The objective of this study was to investigate glucose kinetics during controlled fasting in children with severe pneumonia. Plasma glucose concentration, endogenous glucose production and gluconeogenesis were measured in 12 Surinamese children (six young: 1-3 years, six older: 3-5 years) with severe pneumonia during a controlled 16 h fast using stable isotopes [6,6-(2)H2]glucose and (2)H2O at a hospital-based research facility. On admission, the glucose concentrations were comparable in both groups: young children: 5.1 ± 1.3 mmol/l, older children: 4.8 ± 0.6 mmol/l, p = 0.685, with a decrease during the first 8 h of fasting in the young children only to 3.6 ± 0.5, p = 0.04. Glucose production was comparable in both groups: young: 24.5 ± 8.3, older: 24.9 ± 5.9 µmol/kg(â¢)min, p = 0.926. Between 8 and 16 h of fasting, the glucose concentration decreased comparably in both groups (young: - 0.9 ± 0.7, p = 0.004; older: -1.0 ± 0.4 mmol/l, p = 0.001), as did glucose production (young: -6.8 ± 6.3, p = 0.003; older: -5.3 ± 3.4 µmol/kg(â¢)min, p = 0.001). Gluconeogenesis decreased in young children only: -5.0 ± 7.4, p = 0.029. We conclude that fasting predisposes to hypoglycemia in children with severe pneumonia. Young children are more at risk than older children. Glucose production is an important determinant of the plasma glucose concentration in young children with pneumonia, indicating an inability to reduce glucose usage. Our results are largely in agreement with the literature on the adaptation of glucose metabolism in children with malaria, although there seem to be disease-specific differences in the regulation of gluconeogenesis.
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Glicemia/análise , Jejum/efeitos adversos , Hipoglicemia/etiologia , Pneumonia/complicações , Fatores Etários , Glicemia/metabolismo , Criança , Pré-Escolar , Jejum/metabolismo , Feminino , Gluconeogênese , Humanos , Hipoglicemia/metabolismo , Lactente , Masculino , Pneumonia/diagnóstico , Pneumonia/metabolismo , Índice de Gravidade de Doença , Suriname , Fatores de TempoRESUMO
OBJECTIVE: To measure glucose kinetics and the influence of age, nutritional status and fasting duration in children with uncomplicated falciparum malaria (UFM) under the age of 5 years. METHODS: Plasma glucose concentration, endogenous glucose production (EGP) and gluconeogenesis (GNG) were measured using [6,6-(2)H(2)]glucose and (2)H(2)O in 17 very young (<3 years) and 7 older (3-5 years) Surinamese children with UFM admitted to the Distrikt Hospital Stoelmanseiland and Diakonessen Hospital Paramaribo over 17 months. RESULTS: Plasma glucose concentration was lower in the group of very young children than in the older children (P = 0.028). There were no differences in EGP and GNG between the groups. Overall GNG contributed 56% (median, range 17-87%) to EGP, with no differences between the groups (P = 0.240). Glucose clearance was lower in the older children (P = 0.026). Glucose concentration did not differ between children with weight for length/height less than -1.3 SD and children with weight for length/height greater than -1.3 SD (P = 0.266). Plasma glucose concentration was not predicted by fasting duration (P = 0.762). CONCLUSIONS: Our data suggest a higher risk of hypoglycaemia in very young children with uncomplicated malaria as plasma glucose concentration was lower in this study group. Since this could not be attributed to an impaired EGP, and because glucose clearance was lower in the older children, we presume that older children were better capable of reducing glucose utilization during fasting. Studies on glucose kinetics are feasible in very young children with malaria and give more insight in the pathophysiology of hypoglycaemia.
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Glicemia/biossíntese , Gluconeogênese , Hipoglicemia/sangue , Malária Falciparum/sangue , Fatores Etários , Glicemia/análise , Pré-Escolar , Jejum/sangue , Feminino , Humanos , Lactente , Masculino , Estado Nutricional , Fatores de Risco , SurinameRESUMO
This study addressed health risks from ethnic sausages produced on a small scale, without inspection, in California and elsewhere. Mexican-style chorizo, a raw pork sausage that is not cured, fermented, or smoked, was contaminated experimentally in the batter with Escherichia coli O157:H7, Listeria monocytogenes, or Salmonella serotypes and stuffed into natural casings. Formulations were based on a market survey in California. Physical parameters that were controlled were pH, water activity (a(w)), and storage temperature. The pH was adjusted with vinegar, stabilizing at 5.0 within 24 h. Initial a(w) levels adjusted with salt were 0.97, 0.95, 0.93, 0.90, and 0.85; levels declined with time because of evaporation. Pathogen numbers declined with storage up to 7 days, with few brief exceptions. Main effects and interactions of constant temperature and pH with declining a(w) on survival of the pathogens were determined. Maximum death rates occurred at higher a(w) for E. coli O157:H7 and Salmonella than for L. monocytogenes. Salt used to adjust a(w) affected palatability. Spices (black pepper, chili pepper, chili powder, cumin, garlic, guajillo pepper, oregano, and paprika) comprised another, potentially significant aspect of the sausage formulation. Some (notably black pepper and cumin) carried an indigenous microflora that contributed significantly to the microbial load of the sausage batter. Only undiluted fresh and powdered garlic exhibited a significant antimicrobial effect on the pathogens. Although each of the tested formulations caused death of the inoculated pathogens, none of the death rates was sufficiently rapid to ensure safety within the probable shelf life of the product.
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Qualidade de Produtos para o Consumidor , Escherichia coli O157/crescimento & desenvolvimento , Contaminação de Alimentos/análise , Manipulação de Alimentos/métodos , Listeria monocytogenes/crescimento & desenvolvimento , Produtos da Carne/microbiologia , Salmonella/crescimento & desenvolvimento , Animais , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Humanos , México , Cloreto de Sódio/metabolismo , Cloreto de Sódio/farmacologia , Especiarias , Suínos , Paladar , Temperatura , Fatores de Tempo , Água/metabolismoRESUMO
Mode-mismatched thermal lens (TL) measurements in Cr3+-doped fluoride crystals (LiSrAIF6 and LiSrGaF6) are reported. A nonlinear increase of the TL signal, and decrease of quantum efficiency, with increasing excitation power was observed and attributed to energy-transfer upconversion (ETU). Assuming an upconversion rate that is proportional to the excited-state population, Wup = gammaN(e), the theoretical model developed fits the experimental data well. The ETU parameters (gamma) were determined with unprecedented accuracy for low Cr concentrations. Thermo-optical parameters (K, ds/dT) were also obtained.
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Capillary electrophoresis (CE) and microchannel (MC) techniques are important tools in chemical and biological sciences, mainly in the study of genomes, transcriptomes, proteomes, metabolomes, and organic as well as inorganic ions. The speed of DNA sequencing increased significantly during the last decade with the use of capillary electrophoresis (CE). The time evolution of the bands' spatial profile inside capillaries and channels is of paramount importance, since the main goal of these techniques is to maximize resolution (the ratio between the spacing of the peaks and their mean standard deviations). In the present work, the propagator (retarded Green function) formalism is applied to solve a few problems which are typical for CE and MC. We also apply this mathematical method to the problem of velocity gradients along the capillary, i.e., the time evolution of the bands is analyzed when they enter regions where they migrate with different velocities.