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Spinal cerebrospinal fluid (CSF) volume is the primary determinant for the spread of spinal anesthesia. However, it cannot generally be obtained during spinal anesthesia, and patient physical characteristics are always adopted to obtain a suitable spinal spread. In this study, we sought to explore the relationship between individual physical characteristics and thoracosacral CSF volume to provide a theoretical basis for more accurate spinal anesthesia. In total 35 healthy volunteers were enrolled in this study. Three-dimensional magnetic resonance imaging was used to reconstruct and measure the spinal CSF volume. Physical characteristics and spinal CSF volume were recorded. Bivariate and multiple linear regression analyses were used to analyze the correlation between the individual physical characteristics and thoracosacral CSF volume. Total of 31 participants were included in the final analysis. Bivariate linear correlation analysis showed that the volume of thoracosacral CSF was correlated with both individual dorso-sacral distance and height (both p < 0.01), but not with abdominal girth (p > 0.05). Multiple linear regression analyses revealed that the adjusted R2 values were 0.404 for the regression equation between thoracosacral CSF volume, dorso-sacral distance, and abdominal girth. Our study showed that dorso-sacral distance and abdominal girth were essential factors contributing to thoracosacral CSF volume. A longer dorso-sacral distance and smaller abdominal girth mean larger spinal CSF volume.
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Raquianestesia , Humanos , Raquianestesia/métodos , Sacro , Exame Físico , Abdome , Imageamento por Ressonância Magnética , Líquido Cefalorraquidiano/diagnóstico por imagemRESUMO
BACKGROUND: The dengue epidemic in Guangzhou has imposed a rising burden on society and health infrastructure. Here, we present the genotype data for dengue virus serotype 2 (DENV-2) to improve understanding of this dengue epidemic. METHODS: We sequenced the envelope gene of DENV-2 obtained from patient serum samples and subsequently performed maximum-likelihood phylogenetic analysis using PhyMLv3.1, maximum clade credibility analysis using BEAST v.1.10.4, and selection pressure analysis using Datamonkey 2.0. RESULTS: The prevalent DENV-2 strains identified in Guangzhou region are related to those in Southeast Asian countries. In particular, the Malaysia/Indian subcontinent genotype is prevailing in Guangzhou with no apparent genotype shift having occurred over the past 20 years. However, episodic positive selection was detected at one site. CONCLUSIONS: Local control of the DENV-2 epidemic in Guangzhou requires effective measures to prevent and monitor imported cases. Moreover, the shift between the Malaysia/Indian subcontinent genotype lineages, which originated at different time points, may account for the rise in DENV-2 cases in Guangzhou. Meanwhile, the low rate of dengue haemorrhagic fever in Guangzhou may be explained by the dominance of the less virulent Malaysia/Indian subcontinent genotype.
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Vírus da Dengue , Dengue , Dengue/epidemiologia , Vírus da Dengue/genética , Genótipo , Humanos , Epidemiologia Molecular , Filogenia , SorogrupoRESUMO
OBJECTIVE: To report a de novo splicing mutation in the CSF1R gene in a patient with hereditary diffuse leukoencephalopathy with spheroids (HDLS). METHODS: A 42-year-old Chinese woman with constant weakness on her left lower extremity was recruited in the current study. Detail medical history and clinical characteristics were reviewed. Brain magnetic resonance imaging (MRI), whole-exome sequencing, and Sanger sequencing were performed with bioinformatics analysis. RESULTS: The Chinese HDLS patient with no HDLS family history exhibited a de novo splicing mutation (c.1754-10 T > A) in the CSF1R gene. This mutation was located at the splice site of intron 12 and resulted in the skipping of exon 13 from the CSF1R mRNA. This finding constitutes the first de novo splicing mutation ever reported in HDLS. Furthermore, MRI abnormalities had been reported at least 6 months prior to the onset of the patient's clinical phenotype. CONCLUSION: Our study indicates that the diagnosis of HDLS should be considered even in the absence of a family history and can help deepen the clinical and genetic understanding of HDLS.
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Leucoencefalopatias , Receptor de Fator Estimulador de Colônias de Macrófagos , China , Feminino , Humanos , Leucoencefalopatias/diagnóstico por imagem , Leucoencefalopatias/genética , Imageamento por Ressonância Magnética , Mutação/genética , Receptor de Fator Estimulador de Colônias de Macrófagos/genéticaRESUMO
Plant phenology differs largely among coexisting species within communities that share similar habitat conditions. However, the factors explaining such phenological diversity of plants have not been fully investigated. We hypothesize that species traits, including leaf mass per area (LMA), seed mass, stem tissue mass density (STD), maximum plant height (Hmax), and relative growth rate in height (RGRH), explain variation in plant phenology, and tested this hypothesis in an alpine meadow. Results showed that both LMA and STD were positively correlated with the onset (i.e., beginning) and offset (i.e., ending) times of the four life history events including two reproductive events (flowering and fruiting) and two vegetative events (leafing and senescing). In contrast, RGRH was negatively correlated with the four life phenological events. Moreover, Hmax was positively correlated with reproductive events but not with vegetative events. However, none of the eight phenological events was associated with seed size. In addition, the combination of LMA and STD accounted for 50% of the variation in plant phenologies. Phylogenetic generalized least squares analysis showed plant phylogeny weakened the relationships between species traits vs. phenologies. Phylogeny significantly regulated the variation in the ending but not the beginning of phenologies. Our results indicate that species traits are robust indicators for plant phenologies and can be used to explain the diversity of plant phenologies among co-occurring herbaceous species in grasslands. The findings highlight the important role of the combination of and trade-offs between functional traits in determing plant phenology diversity in the alpine meadow.
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Pradaria , Plantas , Ecossistema , Fenótipo , FilogeniaRESUMO
BACKGROUND: Nine COVID-19 (Corona Virus Disease, 2019) cases were observed in one community in Guangzhou. All the cases lived in three vertically aligned units of one building sharing the same piping system, which provided one unique opportunity to examine the transmission mode of SARS-CoV-2. METHODS: We interviewed the cases on the history of travelling and close contact with the index patients. Respiratory samples from all the cases were collected for viral phylogenetic analyses. A simulation experiment in the building and a parallel control experiment in a similar building were then conducted to investigate the possibility of transmission through air. RESULTS: Index patients living in Apartment 15-b had a travelling history in Wuhan, and four cases who lived in Apartment 25-b and 27-b were subsequently diagnosed. Phylogenetic analyses showed that virus of all the patients were from the same strain of the virus. No close contacts between the index cases and other families indicated that the transmission might not occur through droplet and close contacts. Airflow detection and simulation experiment revealed that flushing the toilets could increase the speed of airflow in the pipes and transmitted the airflow from Apartment 15-b to 25-b and 27-b. Reduced exhaust flow rates in the infected building might have contributed to the outbreak. CONCLUSIONS: The outbreak of COVID-19 in this community could be largely explained by the transmission through air, and future efforts to prevent the infection should take the possibility of transmission through air into consideration. A disconnected drain pipe and exhaust pipe for toilet should be considered in the architectural design to help prevent possible virus spreading through the air.
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In this Letter, we propose a combined metric for quantifying the color discrimination capability of white light sources. This metric is based on considerations of human visual adaptation to daylight chromaticities, as well as on the concerns of the huge spectral diversity of modern light sources. Two existing metrics, Sneutral (degree of neutrality) by Smet et al. [Opt. Express22, 25830 (2014)OPEXFF1094-408710.1364/OE.22.025830] and Rd (hue transposition among color samples of the Farnsworth-Munsell 100 Hue color vision test) by Esposito and Houser [Lighting Res. Technol.51, 5 (2019)LRTEA90024-342610.1177/1477153517729200] were adopted, and their weights were determined by a meta-analysis of five groups of psychophysical data on color discrimination. The superiority of the newly proposed metric was demonstrated by 16 groups of psychophysical data from eight color discrimination studies, as well as by a comparison with 29 typical color quality metrics and their linear combinations.
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Dynamic changes in DNA methylation and demethylation reprogram transcriptional outputs to instruct lineage specification during development. Here, we applied an integrative epigenomic approach to unveil DNA (hydroxy)methylation dynamics representing major endodermal lineage intermediates during pancreatic differentiation of human embryonic stem cells (hESCs). We found that 5-hydroxymethylcytosine (5hmC) marks genomic regions to be demethylated in the descendent lineage, thus reshaping the DNA methylation landscapes during pancreatic lineage progression. DNA hydroxymethylation is positively correlated with enhancer activities and chromatin accessibility, as well as the selective binding of lineage-specific pioneer transcription factors, during pancreatic differentiation. We further discovered enrichment of hydroxymethylated regions (termed '5hmC-rim') at the boundaries of large hypomethylated functional genomic regions, including super-enhancer, DNA methylation canyon and broad-H3K4me3 peaks. We speculate that '5hmC-rim' might safeguard low levels of cytosine methylation at these regions. Our comprehensive analysis highlights the importance of dynamic changes of epigenetic landscapes in driving pancreatic differentiation of hESC.
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Diferenciação Celular/genética , Metilação de DNA , Endoderma/citologia , Células-Tronco Embrionárias Humanas/citologia , Pâncreas/citologia , 5-Metilcitosina/análogos & derivados , 5-Metilcitosina/metabolismo , Linhagem Celular , Linhagem da Célula/genética , Endoderma/metabolismo , Epigênese Genética , Epigenômica , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Embrionárias Humanas/metabolismo , HumanosRESUMO
BACKGROUND: Gut microbiota has been suggested to play a role in stroke patients. Nevertheless, little is known about gut microbiota and the clinical indexes in stroke patients. METHODS: Total of 30 cerebral ischemic stroke (CI) patients and 30 healthy control were enrolled in this study and the fecal gut microbiota was profiled via Illumina sequencing of the 16S rRNA V1-V2. The National Institutes of Health Stroke Scale (NIHSS) were used to quantify stroke severity and modified Rankin scale (mRS) to assess outcome for CI patients. The correlations between the clinical indexes and microbiota were evaluated. RESULTS: Though the microbial α-diversity and structure is similar between CI patients and healthy controls, the gut microbiota of CI patients had more short chain fatty acids producer including Odoribacter, Akkermansia, Ruminococcaceae_UCG_005 and Victivallis. We also found that the special microbes were correlation with serum index, such as norank_O_ _Mollicutes_RF9, Enterobacter, Ruminococcaceae_UCG-002 were negative correlation with LDL (r = - 0.401, P < 0.01), HDL (r = - 0.425, P < 0.01) and blood glucose (r = - 0.439, P < 0.001), while the HDL was significantly positive correlation with the genus Ruminococcus_1 (r = 0.443, P < 0.001). The Christensenellaceae_R-7_group and norank_f_Ruminococcaceae was significantly positive correlation with NIHSS1M (r = 0.514, P < 0.05; r = 0.449, P < 0.05) and mRS (r = 0.471, P < 0.05, r = 0.503, P < 0.01), respectively. On the other hand, the genus Enterobacter was significantly negative correlation with NIHSS1M (r = 0.449, P < 0.05) and mRS (r = 0.503, P < 0.01). CONCLUSIONS: This study suggests that CI patients showed significant dysbiosis of the gut microbiota with enriched short chain fatty acids producer, including Odoribacter, Akkermansia. This dysbiosis was correlation with the outcomes and deserves further study.
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Bactérias/isolamento & purificação , Isquemia Encefálica/microbiologia , Microbioma Gastrointestinal , Acidente Vascular Cerebral/microbiologia , Adulto , Idoso , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Isquemia Encefálica/metabolismo , Estudos de Casos e Controles , Disbiose/metabolismo , Disbiose/microbiologia , Ácidos Graxos Voláteis/metabolismo , Fezes/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/metabolismoRESUMO
Human adenoviruses (HAdVs) were previously detected at high prevalence by real-time reverse transcription-polymerase chain reaction (rRT-PCR) in the upper respiratory tract of residents of two Kenyan refugee camps under surveillance for acute respiratory infection (ARI) between October 2006 and April 2008. We sought to confirm this finding and characterize the HAdVs detected. Of 2148 respiratory specimens originally tested, 511 (23.8%) screened positive for HAdV and 510 were available for retesting. Of these, 421 (82.4%) were confirmed positive by repeat rRT-PCR or PCR and sequencing. Other respiratory viruses were codetected in 55.8% of confirmed HAdV-positive specimens. Species B and C viruses predominated at 82.8%, and HAdV-C1, -C2, and -B3 were the most commonly identified types. Species A, D, and F HAdVs, which are rarely associated with ARI, comprised the remainder. Viral loads were highest among species B HAdVs, particularly HAdV-B3. Species C showed the widest range of viral loads, and species A, D, and F were most often present at low loads and more often with codetections. These findings suggest that many HAdV detections were incidental and not a primary cause of ARI among camp patients. Species/type, codetections, and viral load determinations may permit more accurate HAdV disease burden estimates in these populations.
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Infecções por Adenovirus Humanos/epidemiologia , Adenovírus Humanos/isolamento & purificação , Refugiados , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/classificação , Adolescente , Adulto , Criança , Pré-Escolar , Coinfecção/epidemiologia , Coinfecção/virologia , Feminino , Genótipo , Humanos , Lactente , Quênia/epidemiologia , Masculino , Pessoa de Meia-Idade , Filogenia , Prevalência , Vigilância de Evento Sentinela , Análise de Sequência de DNA , Carga Viral , Adulto JovemRESUMO
During dengue virus (DENV) infection, the virus manipulates different cellular pathways to assure productive replication, including autophagy. However, it remains unclear how this autophagic process is regulated. Here, we have demonstrated a novel role for the microRNA miR-146a in negatively regulating the cellular autophagic pathway in DENV-infected A549 cells and THP-1 cells. Overexpression of miR-146a significantly blocked DENV2-induced autophagy, and LNA-mediated inhibition of miR-146a counteracted these effects. Moreover, co-overexpression of TRAF6, a target of miR-146a, significantly reversed the inhibitory effect of miR-146a on autophagy. Notably, treatment with recombinant IFN-ß fully restored the autophagic activity in TRAF6-silenced cells. Furthermore, our data showed that, in DENV2-infected A549 cells, autophagy promoted a pro-inflammatory response to significantly increase TNF-α and IL-6 production. Taken together, our results define a novel role for miR-146a as a negative regulator of DENV-induced autophagy and identify TRAF6 as a key target of this microRNA in modulating the DENV-autophagy interaction.
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Autofagia , Vírus da Dengue/imunologia , Vírus da Dengue/fisiologia , Interações Hospedeiro-Patógeno , MicroRNAs/metabolismo , Fator 6 Associado a Receptor de TNF/antagonistas & inibidores , Linhagem Celular , Células Epiteliais/imunologia , Células Epiteliais/virologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Monócitos/imunologia , Monócitos/virologiaRESUMO
Cronobacter sakazakii is a severe virulent strain that is frequently detected in powdered infant formula (PIF). Therefore, it is necessary to develop a fast and specific detection method. The specificity of our newly developed quantitative real-time PCR (qRT-PCR) was validated with DNA from 46 strains. Among them, 12 C. sakazakii strains were correctly amplified, whereas no positive florescent signal was observed from 34 nontarget controls. The detection limit of C. sakazakii was about 110 CFU/mL in broth and 1100 CFU/g in PIF. After enrichment in buffered peptone water for 6 h, our developed qRT-PCR assay could reliably detect C. sakazakii when the inoculation level was as low as 2 CFU/25 g (0.08 CFU/g) in PIF. The growth of C. sakazakii could be inhibited by the presence of Lactobacillus pentosus and Bacillus cereus, which used a longer enrichment period before the isolation was accomplished. However, at 5 and 50 CFU/25 g inoculation levels of C. sakazakii in the presence of 4 × 10(6) CFU L. pentosus/25 g or of 2 × 10(4) CFU B. cereus/25 g, the qRT-PCR assay could detect the presence of Cronobacter even though these artificially spiked samples were negative in culture. Therefore, our results indicated that the qRT-PCR assay could detect samples containing inhibitors and could avoid false negatives by using an internal amplification control.
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Cronobacter sakazakii/isolamento & purificação , Proteínas de Escherichia coli/genética , Fórmulas Infantis/microbiologia , Fósforo-Oxigênio Liases/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Cronobacter sakazakii/genética , Microbiologia de Alimentos , Humanos , LactenteRESUMO
MicroRNA-125b (miR-125b) has been implicated in a variety of diseases as either repressors or promoters, and plays crucial roles in many cellular processes such as cell differentiation, proliferation and apoptosis. Age-related cataract has become one of the most serious problems facing the aging population in the world. The purpose of this study was to investigate the role of miR-125b in the development of age-related cataract. We demonstrated that miR-125b was downregulated in both age-related cataract tissue and lens epithelial cell apoptosis induced by UV irradiation. We also identified the impact of miR-125b on apoptosis in a lens epithelial cell line. In vitro, miR-125b regulates human lens epithelial cell apoptosis at least in part by directly targeting p53. In addition,an inverse relationship between miR-125b and p53 expression was seen in age-related cataract tissue. In conclusion,this study suggests that miR-125b might be closely involved in the pathogenesis of cataract, and has the potential to be a diagnostic biomarker or even a therapeutic modality for cataract.
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Apoptose/genética , Catarata/genética , Células Epiteliais/metabolismo , Cristalino/metabolismo , MicroRNAs/genética , Proteína Supressora de Tumor p53/genética , Fatores Etários , Apoptose/efeitos da radiação , Western Blotting , Catarata/patologia , Linhagem Celular , Células Cultivadas , Regulação para Baixo , Citometria de Fluxo , Expressão Gênica , Humanos , Marcação In Situ das Extremidades Cortadas , Cristalino/patologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Raios UltravioletaRESUMO
BACKGROUND AND AIMS: Asymmetric warming is one of the distinguishing features of global climate change, in which winter and night-time temperatures are predicted to increase more than summer and diurnal temperatures. Winter warming weakens vernalization and hence decreases the potential to flower for some perennial herbs, and night warming can reduce carbohydrate concentrations in storage organs. This study therefore hypothesized that asymmetric warming should act to reduce flower number and nectar production per flower in a perennial herb, Saussurea nigrescens, a key nectar plant for pollinators in Tibetan alpine meadows. METHODS: A long-term (6 years) warming experiment was conducted using open-top chambers placed in a natural meadow and manipulated to achieve asymmetric increases in temperature, as follows: a mean annual increase of 0·7 and 2·7 °C during the growing and non-growing seasons, respectively, combined with an increase of 1·6 and 2·8 °C in the daytime and night-time, respectively, from June to August. Measurements were taken of nectar volume and concentration (sucrose content), and also of leaf non-structural carbohydrate content and plant morphology. KEY RESULTS: Six years of experimental warming resulted in reductions in nectar volume per floret (64·7 % of control), floret number per capitulum (8·7 %) and capitulum number per plant (32·5 %), whereas nectar concentration remained unchanged. Depletion of leaf non-structural carbohydrates was significantly higher in the warmed than in the ambient condition. Overall plant density was also reduced by warming, which, when combined with reductions in flower development and nectar volumes, led to a reduction of â¼90 % in nectar production per unit area. CONCLUSIONS: The negative effect of asymmetric warming on nectar yields in S. nigrescens may be explained by a concomitant depletion of leaf non-structural carbohydrates. The results thus highlight a novel aspect of how climate change might affect plant-pollinator interactions and plant reproduction via induction of allocation shifts for plants growing in communities subject to asymmetric warming.
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Asteraceae/metabolismo , Insetos/fisiologia , Néctar de Plantas/metabolismo , Animais , Asteraceae/crescimento & desenvolvimento , Mudança Climática , Flores/crescimento & desenvolvimento , Flores/metabolismo , Pradaria , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Polinização , Reprodução , Estações do Ano , Simbiose , TemperaturaRESUMO
Theory and experiments show that the nature of 'green' trophic cascades, between predators, herbivores and plants, varies with several key species traits: predator hunting mode and predator and prey habitat domains. Meanwhile, 'brown' cascades between predators, environment-modifying detritivores and plants have been largely overlooked and the roles of species traits, particularly prey traits, in determining the nature of these cascades remains unclear. We hypothesize that, in predator-detritivore-plant interaction chains, the burrowing ability of plant-facilitating detritivores determines their response to predators and thus the sign of indirect effect transmitted. In the dung-decomposer food web of an alpine meadow, we predicted that in the presence of above-ground predacious beetles: (i) non-burrowing detritivores will suffer mortality due to predation and transmit negative indirect effects to plants, whereas (ii) burrowing detritivores will escape predation by retreating deeper into the soil, transmitting positive indirect effects to plants. In support of predictions, experiments showed that a single species of predacious beetle (i) reduced the density of the non-burrowing species and indirectly reduced dung loss rate, soil nutrient concentrations and plant biomass, but (ii) drove the burrowing species deeper, indirectly improved soil conditions and increased plant biomass. These results show that the burrowing ability of a detritivore can determine whether it transmits a negative indirect effect mediated by a reduction in its density, or a positive indirect effect mediated by its behavioural response to predation risk. We call for further tests of our detritivore-trait hypothesis in different regions and ecosystems to further develop a general trait-based framework for trophic cascades in detrital food webs. We further advance the general hypothesis that the locomotion traits of prey species (e.g. burrowing/flying ability) may help explain their behavioural response to predation risk and the nature of indirect effect they transmit from predators to plants.
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Besouros/fisiologia , Cadeia Alimentar , Comportamento Predatório , Animais , Locomoção , Solo , Especificidade da Espécie , TibetRESUMO
Studies of grazing food webs show that species traits can interact with environmental factors to determine the strength of trophic cascades, but analogous context dependencies in detrital food webs remain poorly understood. In predator-detritivore-plant interaction chains, predators are expected to indirectly suppress plant biomass by reducing the density of plant-facilitating detritivores. However, this outcome can be reversed where above-ground predators drive burrowing detritivores to lower soil levels, strengthening their plant-facilitating effects. Here, we show that these trait-mediated indirect interactions further depend on environmental context in a Tibetan alpine meadow. In our study system, undulating topography generates higher (dry soil) patches interspersed with lower (wet soil) patches. Because the ability of detritivores to form deep burrows is likely to be limited by oxygen availability in low patches (wet soil), we hypothesized that (i) burrowing detritivores would undergo a vertical habitat shift, allowing them to more effectively avoid predation, in high - but not low - patches, and (ii) this shift would transmit positive effects of predators to plants in high patches by improving conditions in the lower soil layer. We tested these hypotheses using complementary field and glasshouse experiments examining whether the cascading effects of above-ground predatory beetles (presence/absence) on the density and behaviour of tunnel-forming detritivorous beetles, soil properties, and plant growth varied with patch type (low/high). Results revealed that predatory beetles did not reduce the density of detritivores in either patch type but had context-dependent trait-mediated effects, increasing the tunnelling depth of detritivores, improving soil conditions and ultimately increasing plant biomass in the high but not low patches. This study adds to an emerging predictive framework linking predators to plants in detritus food webs, demonstrating that these indirect interactions depend not just on the relative habitat domains of predators and prey, but also on environmental conditions that can predictably constrain the behavioural response of detritivores to predation risk.
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Besouros/fisiologia , Cadeia Alimentar , Pradaria , Comportamento Predatório , Solo , Animais , Ecossistema , Desenvolvimento Vegetal , Fenômenos Fisiológicos Vegetais , TibetRESUMO
Two studies were conducted to investigate the impact of fresh pork display lamps on consumers' sensory responses to pork products. In the first experiment, 63 participants were asked to evaluate pork products with different degrees of freshness under four fresh pork display lights and two LED lights. In the other experiment, 30 subjects participated in the Farnsworth-Munsell 100 hue test under the same lamps, with the aim of showing whether the fresh pork display lamps impaired color discrimination. The results showed that the light source had a significant effect on the color appearance evaluation of the pork products. The ratings for perceived freshness under the fresh pork display lamps were significantly higher than those of ordinary LED lamps, while the color discrimination performance of the subjects under those lamps was poor. It was demonstrated that improper component proportions of the light spectrum could influence observers' assessment of meat quality and weaken the observers' ability to distinguish the freshness level. Through this study, the authors would like to remind lamp users and manufacturers to not only be concerned about the improvement in the color appearance of pork, but also the need for consumers to be aware of the authentic freshness of the pork products.
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Plasmon-mediated chemical reactions (PMCR) have garnered growing interest as a promising concept for photocatalysis. However, in electrochemical systems at solid-liquid interfaces, the photo-induced charge transfer on the surface of metal-semiconductor heterostructures involves complex processes and mechanisms, which are still poorly understood. We explore the plasmon-mediated carrier transfer mechanism and the synergistic effect of light and electric fields on Ag-TiO2 heterostructures, through a combination of electrochemical surface-enhanced Raman spectroscopy and photoelectrochemical methods, with para-aminothiophenol (PATP) serving as a probe molecule. The results show that photocurrent responses are dependent on not only excitation wavelengths and applied potentials, but also the irreversibility of redox. The relationship between photocurrent responses and the chemical transformation between PATP and 4,4'-dimercaptoazobenzene is established, reflecting the photo-induced charge transfer of the heterostructures. The collaboration of spectroscopic and photoelectrochemical methods provide valuable insights into the chemical transformation and kinetic information of adsorbed molecules on the heterostructure during PMCR, offering opportunities for modulating of photocatalytic activities of hot carriers.
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INTRODUCTION: Recent insights regarding mechanisms mediating stemness, heterogeneity, and metastatic potential of lung cancers have yet to be fully translated to effective regimens for the treatment of these malignancies. This study sought to identify novel targets for lung cancer therapy. METHODS: Transcriptomes and DNA methylomes of 14 SCLC and 10 NSCLC lines were compared with normal human small airway epithelial cells (SAECs) and induced pluripotent stem cell (iPSC) clones derived from SAEC. SCLC lines, lung iPSC (Lu-iPSC), and SAEC were further evaluated by DNase I hypersensitive site sequencing (DHS-seq). Changes in chromatin accessibility and depths of transcription factor (TF) footprints were quantified using Bivariate analysis of Genomic Footprint. Standard techniques were used to evaluate growth, tumorigenicity, and changes in transcriptomes and glucose metabolism of SCLC cells after NFIC knockdown and to evaluate NFIC expression in SCLC cells after exposure to BET inhibitors. RESULTS: Considerable commonality of transcriptomes and DNA methylomes was observed between Lu-iPSC and SCLC; however, this analysis was uninformative regarding pathways unique to lung cancer. Linking results of DHS-seq to RNA sequencing enabled identification of networks not previously associated with SCLC. When combined with footprint depth, NFIC, a transcription factor not previously associated with SCLC, had the highest score of occupancy at open chromatin sites. Knockdown of NFIC impaired glucose metabolism, decreased stemness, and inhibited growth of SCLC cells in vitro and in vivo. ChIP-seq analysis identified numerous sites occupied by BRD4 in the NFIC promoter region. Knockdown of BRD4 or treatment with Bromodomain and extra-terminal domain (BET) inhibitors (BETis) markedly reduced NFIC expression in SCLC cells and SCLC PDX models. Approximately 8% of genes down-regulated by BETi treatment were repressed by NFIC knockdown in SCLC, whereas 34% of genes repressed after NFIC knockdown were also down-regulated in SCLC cells after BETi treatment. CONCLUSIONS: NFIC is a key TF and possible mediator of transcriptional regulation by BET family proteins in SCLC. Our findings highlight the potential of genome-wide chromatin accessibility analysis for elucidating mechanisms of pulmonary carcinogenesis and identifying novel targets for lung cancer therapy.
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Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Camundongos , Animais , Carcinoma de Pequenas Células do Pulmão/genética , Carcinoma de Pequenas Células do Pulmão/patologia , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Carcinoma de Pequenas Células do Pulmão/metabolismo , Fatores de Transcrição NFI/genética , Fatores de Transcrição NFI/metabolismo , Estudo de Associação Genômica Ampla , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
BACKGROUND: Dengue virus (DENV) infection is the most prevalent arthropod-borne viral infection in tropical and subtropical regions worldwide. Guangzhou has the ideal environment for DENV transmission and DENV epidemics have been reported in this region for more than 30 years. METHODS: Information for DENV infection cases in Guangzhou from 2001 to 2010 were collected and analyzed. The DENV strains were cultured and isolated from patients' sera. Viral RNA was extracted from cell culture supernatants. cDNA was synthesized by reverse transcription PCR. Phylogenetic trees of four DENV serotypes were constructed respectively. RESULTS: In total, 2478 DENV infection cases were reported; 2143 of these (86.43%) occurred during 3 months of the year: August, September and October. Of these, 2398 were local cases (96.77%) and 80 were imported cases (3.23%). Among the imported cases, 69 (86.25%) were from Southeast Asian countries. From the 90 isolated strains, 66.67%, 3.33%, 14.44%, and 15.56% belonged to DENV serotypes 1, 2, 3, and 4, respectively. DENV-1 was predominant in most of the years, including during 2 outbreaks in 2002 and 2006; however, none of the strains or genotypes identified in this study were found to be predominant. Interestingly, DENV strains from different years had different origins. Moreover, the strains from each year belonged to different serotypes and/or genotypes. CONCLUSIONS: Southeast Asia countries were found to be the possible source of DENV in Guangzhou. These findings suggest that there is increasing diversity in DENV strains in Guangzhou, which could increase the risk of DENV outbreaks in the near future.
Assuntos
Vírus da Dengue/classificação , Vírus da Dengue/genética , Dengue/epidemiologia , Dengue/virologia , RNA Viral/genética , China/epidemiologia , Análise por Conglomerados , Vírus da Dengue/isolamento & purificação , Genótipo , Humanos , Epidemiologia Molecular , Dados de Sequência Molecular , Filogenia , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNARESUMO
Theory suggests that predators of soil-improving, plant-facilitating detritivores (e.g. earthworms) should suppress plant growth via a negative tri-trophic cascade, but the empirical evidence is still largely lacking. We tested this prediction in an alpine meadow on the Tibetan Plateau by manipulating predatory beetles (presence/absence) and quantifying (i) direct effects on the density and behaviour of earthworms; and (ii) indirect effects on soil properties and above-ground plant biomass. In the absence of predators, earthworms improved soil properties, but did not significantly affect plant biomass. Surprisingly, the presence of predators strengthened the positive effect of earthworms on soil properties leading to the emergence of a positive indirect effect of predators on plant biomass. We attribute this counterintuitive result to: (i) the inability of predators to suppress overall earthworm density; and (ii) the predator-induced earthworm habitat shift from the upper to lower soil layer that enhanced their soil-modifying, plant-facilitating, effects. Our results reveal that plant-level consequences of predators as transmitted through detritivores can hinge on behaviour-mediated indirect interactions that have the potential to overturn predictions based solely on trophic interactions. This work calls for a closer examination of the effects of predators in detritus food webs and the development of spatially explicit theory capable of predicting the occurrence and consequences of predator-induced detritivore behavioural shifts.