1,229 research outputs found

    Practical Science and Environmental Education Workshop in Manaus, Brazil

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    It is an unequivocal fact that Amazonian tropical forest is the largest remaining primary forest in the world. The ecosystem in the region is e tremely comple with high biodiversity (Peres et al. 2010). Conservation and protection of the dynamic forest and river regions is e tremely important not only for the natural environments, but also for the economy and social dependence of benefits from such abundant natural environments. Important natural parameters that affect status of the natural environments include light (natural sunlight), soil, and water, which abundantly e ist in the Amazon region. Solar energy is the primary energy source for the majority of living organisms in both terrestrial and aquatic ecosystems, and drives the diurnal and seasonal cycles of biogeochemical processes (Monteith & Unsworth 2013). In particular, in situ light data remains one of the most underappreciated data measurements although having a significant impact on the physical, chemical and biological processes in the ecosystem (Johnsen 2012). Soil provides the fundamental basis for all terrestrial living organisms including the Amazonian forests as well as life-sustaining infrastructure for human society. Water is the most essential single entity to constitute all organisms from a single cell to the earth. Understanding of importance and roles of each factor and interaction of such comple dynamics in the natural environments can serve as fundamental platform for natural scientists, particularly for young scientists such as university students. The objective of this workshop was to provide hand- on scientific and environmental education for university students in Manaus, Amazonas, Brazil through practical field measurements using the three most important parameters in the natural ecosystem composed of natural sunlight, soil, and water. The workshop was divided into a series of lectures, in situ field sampling, and data processing, analysis and interpretation with the ultimate goal of empowering the undergraduate students with research-centered environmental education and e perience of developing international collaboration.departmental bulletin pape

    Chemical Composition and Evaluation of Antitumoral Activity of Leaf and Root Essential Oils of Conyza canadensis (Asteraceae)

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    The leaf and root oils of Conyza canadensis were studied for chemical composition and antitumor activity. The results showed that there is great variation in the composition of the oils obtained from different parts. The main components in the leaf oil were limonene, caryophyllene oxide and espatulenol. In the root oil the major component was the acetylenic ester lachnophyllum methyl ester. It was observed that according to the collection time (6 and 16 hours), significant variations in the content of the main components of this essential oil of leaves can occur. Limonene, spatulenol and caryophyllene oxide presented a distribution of 61% / 5.4% / 12.5% ​​and 38% / 10.7% / 22.3% in oils obtained from plants collected at 6 and 16 hours, respectively. The antitumor activity of the oils showed that leaf oil had a greater potential for inhibition, and this oil was distinguished by the activity against neoplastic cell lines K562 (leukemia) and NCI-ADR / RES (ovary with multidrug resistance phenotype ) with TGI values ​​of 16.8 and 19.0 mg.mL-1, respectively. Comparing the leaf oils and their tumor cell inhibition potentials, it was noted that this activity is higher in the oil with higher contents of monoterpene limonene. DOI: http://dx.doi.org/10.17807/orbital.v11i5.137

    Mitochondrial Bioenergetic Alterations in Mouse Neuroblastoma Cells Infected with Sindbis Virus: Implications to Viral Replication and Neuronal Death

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    The metabolic resources crucial for viral replication are provided by the host. Details of the mechanisms by which viruses interact with host metabolism, altering and recruiting high free-energy molecules for their own replication, remain unknown. Sindbis virus, the prototype of and most widespread alphavirus, causes outbreaks of arthritis in humans and serves as a model for the study of the pathogenesis of neurological diseases induced by alphaviruses in mice. In this work, respirometric analysis was used to evaluate the effects of Sindbis virus infection on mitochondrial bioenergetics of a mouse neuroblastoma cell lineage, Neuro 2a. The modulation of mitochondrial functions affected cellular ATP content and this was synchronous with Sindbis virus replication cycle and cell death. At 15 h, irrespective of effects on cell viability, viral replication induced a decrease in oxygen consumption uncoupled to ATP synthesis and a 36% decrease in maximum uncoupled respiration, which led to an increase of 30% in the fraction of oxygen consumption used for ATP synthesis. Decreased proton leak associated to complex I respiration contributed to the apparent improvement of mitochondrial function. Cellular ATP content was not affected by infection. After 24 h, mitochondria dysfunction was clearly observed as maximum uncoupled respiration reduced 65%, along with a decrease in the fraction of oxygen consumption used for ATP synthesis. Suppressed respiration driven by complexes I- and II-related substrates seemed to play a role in mitochondrial dysfunction. Despite the increase in glucose uptake and glycolytic flux, these changes were followed by a 30% decrease in ATP content and neuronal death. Taken together, mitochondrial bioenergetics is modulated during Sindbis virus infection in such a way as to favor ATP synthesis required to support active viral replication. These early changes in metabolism of Neuro 2a cells may form the molecular basis of neuronal dysfunction and Sindbis virus-induced encephalitis

    Spatial patterns and temporal variability of drought in Western Iran

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    An analysis of drought in western Iran from 1966 to 2000 is presented using monthly precipitation data observed at 140 gauges uniformly distributed over the area. Drought conditions have been assessed by means of the Standardized Precipitation Index (SPI). To study the long-term drought variability the principal component analysis was applied to the SPI field computed on 12-month time scale. The analysis shows that applying an orthogonal rotation to the first two principal component patterns, two distinct sub-regions having different climatic variability may be identified. Results have been compared to those obtained for the largescale using re-analysis data suggesting a satisfactory agreement. Furthermore, the extension of the large-scale analysis to a longer period (1948–2007) shows that the spatial patterns and the associated time variability of drought are subjected to noticeable changes. Finally, the relationship between hydrological droughts in the two sub-regions and El Niño Southern Oscillation events has been investigated finding that there is not clear evidence for a link between the two phenomen

    The Portuguese Society of Rheumatology position paper on the use of biosimilars

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    Biotechnological drugs have become a fundamental resource for the treatment of rheumatic patients. Patent expiry of some of these drugs created the opportunity for biopharmaceutical manufacturers to develop biosimilar drugs intended to be as efficacious as the originator product but with a lower cost to healthcare systems. Due to the complex manufacturing process and highly intricate structure of biologicals, a biosimilar can never be an exact copy of its reference product. Consequently, regulatory authorities issued strict preclinical and clinical guidelines to ensure safety and efficacy equivalence and, in September 2013, the biosimilar of infliximab was the first biosimilar monoclonal antibody to be authorized for use in the European Union. The current document is a position statement of the "Sociedade Portuguesa de Reumatologia" (Portuguese Society of Rheumatology) on the use of biosimilar drugs in rheumatic diseases. Two systematic literature reviews were performed, one concerning clinical trials and the other one concerning international position papers on biosimilars. The results were presented and discussed in a national meeting and a final position document was discussed, written and approved by Portuguese rheumatologists. Briefly, this position statement is contrary to automatic substitution of the originator by the biosimilar, defends either a different INN or the prescription by brand name, supports that switching between biosimilars and the originator molecule should be done after at least 6 months of treatment and based on the attending physician decision and after adequate patient information, recommends the registration of all biosimilar treated patients in Reuma.pt for efficacy, safety and immunogenicity surveillance, following the strategy already ongoing for originators, and opposes to extrapolation of indications approved to the originator to completely different diseases and/or age groups without adequate pre-clinical, safety or efficacy data.info:eu-repo/semantics/publishedVersio
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