270 research outputs found

    Daytime turbulent exchange between the Amazon forest and the atmosphere

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    Detailed observations of turbulence just above and below the crown of the Amazon rain forest during the wet season are presented. The forest canopy is shown to remove high frequency turbulent fluctuations while passing lower frequencies. Filter characteristics of turbulent transfer into the Amazon rain forest canopy are quantified. Simple empirical relations that relate observed turbulent heat fluxes to horizontal wind variance are presented. Changes in the amount of turbulent coupling between the forest and the boundary layer associated with deep convective clouds are presented both as statistical averages and as a series of case studies. These convective processes during the rainy season are shown to alter the diurnal course of turbulent fluxes. In wake of giant coastal systems, no significant heat or moisture fluxes occur for up to a day after the event. Radar data is used to demonstrate that even small raining clouds are capable of evacuating the canopy of substances normally trapped by persistent static stability near the forest floor. Recovery from these events can take more than an hour, even during mid-day. In spite of the ubiquitous presence of clouds and frequent rain during this season, the average horizontal wind speed spectrum is well described by dry CBL similarity hypotheses originally found to apply in flat terrain

    Solubility of caffeic acid in CO2 + ethanol: experimental and predicted data using Cubic Plus Association Equation of State

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    This work evaluated the solubility of caffeic acid (CA) in mixtures of supercritical carbon dioxide (scCO2) and ethanol at different temperatures (313, 323 and 333 K), pressures (20, 30 and 40 MPa) and concentrations of ethanol (2.2, 5.4 and 10.2 mol%). The Soave-Redlich-Kwong and Cubic Plus Association (CPA) equations of state were used to correlate the binary mixture data and to predict the ternary system data. CA solubility in ethanol is approximately 106 times higher than its solubility in pure scCO2. By using 10.2 mol% ethanol in scCO2, CA solubility increased 30,000 times at 313 K and 20 MPa. Both models provided reasonable descriptions of the experimental data for the binary systems. However, CPA-EoS can better describe the strong interactions between acid molecules and ethanol, and can predict that the addition of small amounts of ethanol to scCO2 provides a large increase in CA solubility.publishe

    Role of metformin and other metabolic drugs in the prevention and therapy of endocrine-related cancers

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    Metabolic syndrome is associated with chronic diseases, including type 2 diabetes, cardiovascular diseases, and cancer. This review summarizes the current evidence on the antitumor effects of some relevant drugs currently used to manage metabolic-related pathologies (i.e. insulin and its analogs, metformin, statins, etc.) in endocrine-related cancers including breast cancer, prostate cancer, pituitary cancer, ovarian cancer, and neuroendocrine neoplasms. Although current evidence does not provide a clear antitumor role of several of these drugs, metformin seems to be a promising chemopreventive and adjuvant agent in cancer management, modulating tumor cell metabolism and microenvironment, through both AMP-activated protein kinase-dependent and -independent mechanisms. Moreover, its combination with statins might represent a promising therapeutic strategy to tackle the progression of endocrine-related tumors. However, further studies are needed to endorse the clinical relevance of these drugs as adjuvants for cancer chemotherapy.Ministerio de Ciencia e Innovación de España. PID2019- 105564RB-I00/FPU16-05059Fondo Europeo de Desarrollo Regional (FEDER) y Fondo Social Europeo (FSE). PI20/01301Instituto de Salud Carlos III de España. SCIII-AES-2019/002525Junta de Andalucía. PI-0152-2019, PI-0094-2020, PI-0038/2019, RH-0084-2020 y BIO-013

    Polyneuropathy in the critical ill patient: a common diagnosis in intensive care medicine?

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    BACKGROUND AND OBJECTIVES: The diffuse axonal polyneuropathy, more commonly known as Critical Illness Polyneuropathy (CIP), has been discussed by authors by decades; however, it has only been deeply studied over the last thirty years, becoming more important as an important cause of long term dependence on mechanical ventilation by seriously ill patients in intensive care medicine. CONTENTS: A significant reason for such interest is due to the importance of the CIP as complication of the septic shock and in patients with multiple organ failure, as much as responsible for the prolonging hospitalization in the Intensive Care Unit, as for the gradual reduction of the chance of survival. It has been suggested that the polyneuropathy is related with cytokines and other mediators which would increase the permeability of the vases, resulting in endoneural edema and causing the axonal injury. It is difficult to do the initial diagnostic, which, in general, are only possibly recognized when the sepsis complications or the multiple organs failure have been satisfactorily controlled. The diagnosis is made through the eletroneuromiography exam, and although there is still no effective drug treatment other than the control of the basic illness, it is consensus among multidisciplinary team that the development of the CIP does not have to be understood as a way to reduce the intensity of treatment. CONCLUSIONS: Spit of your prevalence, it is still unknown the mainly factors which are physiopathology associated as soon as your correct therapy.JUSTIFICATIVA E OBJETIVOS: A polineuropatia axonal difusa, hoje mais conhecida como polineuropatia do paciente crítico (PPC), tem sido relatada por autores há décadas, porém, apenas nos últimos 30 anos, ocupa maior importância como causa de dependência prolongada de ventilação mecânica, em pacientes gravemente enfermos internados em Unidades de Terapia Intensiva. Esta revisão teve por objetivo apresentar os princípios tópicos que norteiam a fisiopatologia, diagnóstico e tratamento desta doença em Medicina intensiva. CONTEÚDO: A importância da PPC como complicação inicial do choque séptico e em pacientes com disfunção de múltiplos de órgãos e sistemas (DMOS) está claramente descrita como responsável pelo prolongamento da permanência na UTI e, também pela redução gradativa da probabilidade de sobrevida. Sugere-se que a polineuropatia esteja relacionada com as citocinas envolvidas na sepse, além de outros mediadores que aumentariam a permeabilidade dos vasos, resultando em edema endoneural e lesão axonal. Seu início é de difícil diagnóstico, geralmente sendo possível apenas quando as complicações da sepse ou falência de múltiplos órgãos tenham sido adequadamente controladas. O diagnóstico é feito através da eletroneuromiografia. Apesar de ainda não haver nenhum tratamento medicamentoso efetivo, além do controle da doença de base, é censo comum, entre equipes multidisciplinares que o desenvolvimento da PPC não deve ser entendido como forma de reduzir os esforços do tratamento. CONLUSÕES: A despeito de sua prevalência, ainda permanecem desconhecidos os fatores claramente associados à sua fisiopatologia, bem como adequada terapia para o manuseio desta condição.UNIFESP-EPMAMIB AMBUNIFESP, EPMSciEL

    Role of metformin and other metabolic drugs in the prevention and therapy of endocrine-related cancers

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    Metabolic syndrome is associated with chronic diseases, including type 2 diabetes, cardiovascular diseases, and cancer. This review summarizes the current evidence on the antitumor effects of some relevant drugs currently used to manage metabolic-related pathologies (i.e. insulin and its analogs, metformin, statins, etc.) in endocrine-related cancers including breast cancer, prostate cancer, pituitary cancer, ovarian cancer, and neuroendocrine neoplasms. Although current evidence does not provide a clear antitumor role of several of these drugs, metformin seems to be a promising chemopreventive and adjuvant agent in cancer management, modulating tumor cell metabolism and microenvironment, through both AMP-activated protein kinase–dependent and –independent mechanisms. Moreover, its combination with statins might represent a promising therapeutic strategy to tackle the progression of endocrine-related tumors. However, further studies are needed to endorse the clinical relevance of these drugs as adjuvants for cancer chemotherapy

    HIF-transcribed p53 chaperones HIF-1α

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    Chronic hypoxia is associated with a variety of physiological conditions such as rheumatoid arthritis, ischemia/reperfusion injury, stroke, diabetic vasculopathy, epilepsy and cancer. At the molecular level, hypoxia manifests its effects via activation of HIF-dependent transcription. On the other hand, an important transcription factor p53, which controls a myriad of biological functions, is rendered transcriptionally inactive under hypoxic conditions. p53 and HIF-1α are known to share a mysterious relationship and play an ambiguous role in the regulation of hypoxia-induced cellular changes. Here we demonstrate a novel pathway where HIF-1α transcriptionally upregulates both WT and MT p53 by binding to five response elements in p53 promoter. In hypoxic cells, this HIF-1α-induced p53 is transcriptionally inefficient but is abundantly available for protein-protein interactions. Further, both WT and MT p53 proteins bind and chaperone HIF-1α to stabilize its binding at its downstream DNA response elements. This p53-induced chaperoning of HIF-1α increases synthesis of HIF-regulated genes and thus the efficiency of hypoxia-induced molecular changes. This basic biology finding has important implications not only in the design of anti-cancer strategies but also for other physiological conditions where hypoxia results in disease manifestation

    Oral chondroitin sulfate and prebiotics for the treatment of canine Inflammatory Bowel Disease: a randomized, controlled clinical trial

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    BACKGROUND Canine inflammatory bowel disease (IBD) is a chronic enteropathy of unknown etiology, although microbiome dysbiosis, genetic susceptibility, and dietary and/or environmental factors are hypothesized to be involved in its pathogenesis. Since some of the current therapies are associated with severe side effects, novel therapeutic modalities are needed. A new oral supplement for long-term management of canine IBD containing chondroitin sulfate (CS) and prebiotics (resistant starch, β-glucans and mannaoligosaccharides) was developed to target intestinal inflammation and oxidative stress, and restore normobiosis, without exhibiting any side effects. This double-blinded, randomized, placebo-controlled trial in dogs with IBD aims to evaluate the effects of 180 days administration of this supplement together with a hydrolyzed diet on clinical signs, intestinal histology, gut microbiota, and serum biomarkers of inflammation and oxidative stress. RESULTS Twenty-seven client-owned biopsy-confirmed IBD dogs were included in the study, switched to the same hydrolyzed diet and classified into one of two groups: supplement and placebo. Initially, there were no significant differences between groups (p > 0.05) for any of the studied parameters. Final data analysis (supplement: n = 9; placebo: n = 10) showed a significant decrease in canine IBD activity index (CIBDAI) score in both groups after treatment (p < 0.001). After treatment, a significant decrease (1.53-fold; p < 0.01) in histologic score was seen only in the supplement group. When groups were compared, the supplement group showed significantly higher serum cholesterol (p < 0.05) and paraoxonase-1 (PON1) levels after 60 days of treatment (p < 0.01), and the placebo group showed significantly reduced serum total antioxidant capacity (TAC) levels after 120 days (p < 0.05). No significant differences were found between groups at any time point for CIBDAI, WSAVA histologic score and fecal microbiota evaluated by PCR-restriction fragment length polymorphism (PCR-RFLP). No side effects were reported in any group. CONCLUSIONS The combined administration of the supplement with hydrolyzed diet over 180 days was safe and induced improvements in selected serum biomarkers, possibly suggesting a reduction in disease activity. This study was likely underpowered, therefore larger studies are warranted in order to demonstrate a supplemental effect to dietary treatment of this supplement on intestinal histology and CIBDAI

    GW150914: First search for the electromagnetic counterpart of a gravitational-wave event by the TOROS collaboration

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    We present the results of the optical follow-up conducted by the TOROS collaboration of the first gravitational-wave event GW150914. We conducted unfiltered CCD observations (0.35-1 micron) with the 1.5-m telescope at Bosque Alegre starting ~2.5 days after the alarm. Given our limited field of view (~100 square arcmin), we targeted 14 nearby galaxies that were observable from the site and were located within the area of higher localization probability. We analyzed the observations using two independent implementations of difference-imaging algorithms, followed by a Random-Forest-based algorithm to discriminate between real and bogus transients. We did not find any bona fide transient event in the surveyed area down to a 5-sigma limiting magnitude of r=21.7 mag (AB). Our result is consistent with the LIGO detection of a binary black hole merger, for which no electromagnetic counterparts are expected, and with the expected rates of other astrophysical transients.Comment: ApJ Letters, in pres

    Oral lichen planus: A retrospective study of 110 Brazilian patients

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    <p>Abstract</p> <p>Background</p> <p>Oral lichen planus (OLP) is a chronic autoimmune disease characterized by multiple clinical presentations and a relatively high prevalence in the population. This retrospective patient record study investigated the profile of OLP in a group of Brazilian patients seen between 1989 and 2009.</p> <p>Findings</p> <p>The clinical records were analyzed and data such as gender, age, race, clinical presentation of OLP, site affected, presence of symptoms and extraoral manifestations of the disease, smoking habit, and consumption of alcoholic beverages were obtained. Among the 1822 records of patients with oral mucosal lesions, OLP was identified in 6.03%. Of these, 76.36% were females, with a mean age of 54 years, and 85% were whites. The reticular form was the most frequent (81.81%). Extraoral lesions were observed in 32.72% of the patients and painful symptoms were reported by 50.90%. The cheek mucosa was the site most affected (92.72%) and multiple oral lesions were observed in 77.27% of the patients. Among patients with OLP, 18.18% reported a smoking habit and 29.09% the consumption of alcoholic beverages.</p> <p>Conclusions</p> <p>This retrospective study showed a relatively high prevalence of OLP in the population studied, with a predominance of the disease among middle-aged white women and bilateral involvement of the cheek mucosa. Reticular lesions were the most frequent, followed by the erosive form which is mainly associated with painful symptoms. No relationship with tobacco or alcohol consumption was observed.</p
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