945 resultados para plants regulators
Resumo:
More than 20% of the world's biodiversity is located in Brazilian forests and only a few plant extracts have been evaluated for potential antibacterial activity. In the present study, 705 organic and aqueous extracts of plants obtained from different Amazon Rain Forest and Atlantic Forest plants were screened for antibacterial activity at 100 µg/ml, using a microdilution broth assay against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli. One extract, VO581, was active against S. aureus (minimum inhibitory concentration (MIC) = 140 µg/ml and minimal bactericidal concentration (MBC) = 160 µg/ml, organic extract obtained from stems) and two extracts were active against E. faecalis, SM053 (MIC = 80 µg/ml and MBC = 90 µg/ml, organic extract obtained from aerial parts), and MY841 (MIC = 30 µg/ml and MBC = 50 µg/ml, organic extract obtained from stems). The most active fractions are being fractionated to identify their active substances. Higher concentrations of other extracts are currently being evaluated against the same microorganisms.
Resumo:
Työn tavoitteena on kehittää ABB:lle palvelutuote, jota voidaan tarjota voimalaitosasiakkaille. Uuden palvelutuotteen tulee vastata ABB:n uuden strategian linjauksiin. Palvelulla tarjotaan asiakkaille 1.1.2015 voimaan tulleen energiatehokkuuslain määrittelemien pakollisten toimenpiteiden suoritusta. Työssä kerätään, käsitellään ja analysoidaan tietoa voimalaitosasiakkaille suunnatun palvelun tuotteistamisprosessin päätöksenteon tueksi. Palvelutuotteen kehittämistä varten tutkitaan ABB:n nykyisiä palvelutuotteita, osaamista ja referenssi projekteja, energiatehokkuuslakia, voimalaitosten energiatehokkuus-potentiaalia ja erilaisia energiakatselmusmalleja. Päätöksenteon tueksi tehdään referenssiprojektina energia-analyysi voimalaitokselle, jossa voimalaitoksesta tehdään ipsePRO simulointiohjelmalla mallinnus. Mallinnuksen ja koeajojen avulla tutkitaan voimalaitoksen minimikuorman optimointia. Markkinatutkimuksessa selvitetään lainsäädännön vaikutusta, nykyistä markkinatilannetta, potentiaalisia asiakkaita, kilpailijoita ja ABB:n mahdollisuuksia toimia alalla SWOT–analyysin avulla. Tutkimuksen tulosten perusteella tehdään päätös tuotteistaa voimalaitoksille palvelutuote, joka sisältää kaikki toimet energiatehokkuuslain asettamien vaatimusten täyttämiseen yrityksen energiakatselmuksen vastuuhenkilön, energiakatselmuksen ja kohdekatselmuksien teon osalta. Lisäksi työn aikana Energiavirasto myönsi ABB:lle pätevyyden toimia yrityksen energiakatselmuksen vastuuhenkilönä, mikä on edellytyksenä palvelun tarjoamiselle.
Resumo:
We determined the neutralizing activity of 12 ethanolic extracts of plants against the edema-forming, defibrinating and coagulant effects of Bothrops asper venom in Swiss Webster mice. The material used consisted of the leaves and branches of Bixa orellana (Bixaceae), Ficus nymphaeifolia (Moraceae), Struthanthus orbicularis (Loranthaceae) and Gonzalagunia panamensis (Rubiaceae); the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); the whole plant of Pleopeltis percussa (Polypodiaceae) and Trichomanes elegans (Hymenophyllaceae); rhizomes of Renealmia alpinia (Zingiberaceae), Heliconia curtispatha (Heliconiaceae) and Dracontium croatii (Araceae), and the ripe fruit of Citrus limon (Rutaceae). After preincubation of varying amounts of each extract with either 1.0 µg venom for the edema-forming effect or 2.0 µg venom for the defibrinating effect, the mixture was injected subcutaneously (sc) into the right foot pad or intravenously into the tail, respectively, to groups of four mice (18-20 g). All extracts (6.2-200 µg/mouse) partially neutralized the edema-forming activity of venom in a dose-dependent manner (58-76% inhibition), with B. orellana, S. orbicularis, G. panamensis, B. rosademonte, and D. croatii showing the highest effect. Ten extracts (3.9-2000 µg/mouse) also showed 100% neutralizing ability against the defibrinating effect of venom, and nine prolonged the coagulation time induced by the venom. When the extracts were administered either before or after venom injection, the neutralization of the edema-forming effect was lower than 40% for all extracts, and none of them neutralized the defibrinating effect of venom. When they were administered in situ (sc at the same site 5 min after venom injection), the neutralization of edema increased for six extracts, reaching levels up to 64% for C. limon.
Resumo:
Molecular oxygen (O2) is the premier biological electron acceptor that serves vital roles in fundamental cellular functions. However, with the beneficial properties of O2 comes the inadvertent formation of reactive oxygen species (ROS) such as superoxide (O2·-), hydrogen peroxide, and hydroxyl radical (OH·). If unabated, ROS pose a serious threat to or cause the death of aerobic cells. To minimize the damaging effects of ROS, aerobic organisms evolved non-enzymatic and enzymatic antioxidant defenses. The latter include catalases, peroxidases, superoxide dismutases, and glutathione S-transferases (GST). Cellular ROS-sensing mechanisms are not well understood, but a number of transcription factors that regulate the expression of antioxidant genes are well characterized in prokaryotes and in yeast. In higher eukaryotes, oxidative stress responses are more complex and modulated by several regulators. In mammalian systems, two classes of transcription factors, nuclear factor kB and activator protein-1, are involved in the oxidative stress response. Antioxidant-specific gene induction, involved in xenobiotic metabolism, is mediated by the "antioxidant responsive element" (ARE) commonly found in the promoter region of such genes. ARE is present in mammalian GST, metallothioneine-I and MnSod genes, but has not been found in plant Gst genes. However, ARE is present in the promoter region of the three maize catalase (Cat) genes. In plants, ROS have been implicated in the damaging effects of various environmental stress conditions. Many plant defense genes are activated in response to these conditions, including the three maize Cat and some of the superoxide dismutase (Sod) genes.
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Leishmaniasis, Chagas' disease and schistosomiasis (bilharzia) are parasitic diseases with wide distribution on the American continent, affecting millions of people. In the present study, biological assays for antiprotozoal and molluscicidal activities were carried out with ethanolic extracts of plant species from the Brazilian part of the Upper Paraná River. Crude extracts were obtained by percolation with absolute ethanol from the leaves of Cayaponia podantha Cogn., Nectandra falcifolia (Nees) Castiglioni and Paullinia elegans Cambess., as well as from the aerial parts of Helicteres gardneriana St. Hil. & Naud. and Melochia arenosa Benth., all belonging to genera used in folk medicine. Trypanocidal activity of plants was assayed on epimastigote cultures in liver infusion tryptose. Anti-leishmanial activity was determined over cultures of promastigote forms of the parasite in Schneider's Drosophila medium. Microscopic countings of parasites, after their incubation in the presence of different concentrations of the crude extracts, were made in order to determine the percentage of growth inhibition. C. podantha and M. arenosa, at a concentration of 10 µg/mL, showed 90.4 ± 11.52 and 88.9 ± 2.20% growth inhibition, respectively, of epimastigote forms of Trypanosoma cruzi, whereas N. falcifolia demonstrated an LD50 of 138.5 µg/mL against promastigote forms of Leishmania (Viannia) braziliensis. Regarding molluscicidal activity, the acute toxicity of the extracts on Biomphalaria glabrata was evaluated by a rapid screening procedure. M. arenosa was 100% lethal to snails at 200 µg/mL and showed an LD50 of 143 µg/mL. Screening of plant extracts represents a continuous effort to find new antiparasitic drugs.
Resumo:
Repowering existing power plants by replacing coal with biomass might offer an interesting option to ease the transition from fossil fuels to renewable energy sources and promote a fur-ther expansion of bioenergy in Europe, on account of the potential to decrease greenhouse gas emissions, as well as other pollutants (SOx, NOx, etcetera). In addition, a great part of the appeal of repowering projects comes from the opportunity to reuse the vast existing invest-ment and infrastructure associated with coal-based power generation. Even so, only a limited number of experiences with repowering are found. Therefore, efforts are required to produce technical and scientific evidence to determine whether said technology might be considered feasible for its adoption within European conditions. A detailed evaluation of the technical and economic aspects of this technology constitutes a powerful tool for decision makers to define the energy future for Europe. To better illustrate this concept, a case study is analyzed. A Slovakian pulverized coal plant was used as the basis for determining the effects on perfor-mance, operation, maintenance and cost when fuel is shifted to biomass. It was found that biomass fuel properties play a crucial role in plant repowering. Furthermore, results demon-strate that this technology offers renewable energy with low pollutant emissions at the cost of reduced capacity, relatively high levelized cost of electricity and sometimes, a maintenance-intensive operation. Lastly, regardless of the fact that existing equipment can be reutilized for the most part, extensive additions/modifications may be required to ensure a safe operation and an acceptable performance.
Resumo:
Because histopathological changes in the lungs of patients with systemic sclerosis (SSc) are consistent with alveolar and vessel cell damage, we presume that this interaction can be characterized by analyzing the expression of proteins regulating nitric oxide (NO) and plasminogen activator inhibitor-1 (PAI-1) synthesis. To validate the importance of alveolar-vascular interactions and to explore the quantitative relationship between these factors and other clinical data, we studied these markers in 23 cases of SSc nonspecific interstitial pneumonia (SSc-NSIP). We used immunohistochemistry and morphometry to evaluate the amount of cells in alveolar septa and vessels staining for NO synthase (NOS) and PAI-1, and the outcomes of our study were cellular and fibrotic NSIP, pulmonary function tests, and survival time until death. General linear model analysis demonstrated that staining for septal inducible NOS (iNOS) related significantly to staining of septal cells for interleukin (IL)-4 and to septal IL-13. In univariate analysis, higher levels of septal and vascular cells staining for iNOS were associated with a smaller percentage of septal and vascular cells expressing fibroblast growth factor and myofibroblast proliferation, respectively. Multivariate Cox model analysis demonstrated that, after controlling for SSc-NSIP histological patterns, just three variables were significantly associated with survival time: septal iNOS (P=0.04), septal IL-13 (P=0.03), and septal basic fibroblast growth factor (bFGF; P=0.02). Augmented NOS, IL-13, and bFGF in SSc-NSIP histological patterns suggest a possible functional role for iNOS in SSc. In addition, the extent of iNOS, PAI-1, and IL-4 staining in alveolar septa and vessels provides a possible independent diagnostic measure for the degree of pulmonary dysfunction and fibrosis with an impact on the survival of patients with SSc.
Resumo:
The aim of this research was to investigate the antiproliferative and anticholinesterase activities of 11 extracts from 5 Annonaceae species in vitro. Antiproliferative activity was assessed using 10 human cancer cell lines. Thin-layer chromatography and a microplate assay were used to screen the extracts for acetylcholinesterase (AchE) inhibitors using Ellman's reagent. The chemical compositions of the active extracts were investigated using high performance liquid chromatography. Eleven extracts obtained from five Annonaceae plant species were active and were particularly effective against the UA251, NCI-470 lung, HT-29, NCI/ADR, and K-562 cell lines with growth inhibition (GI50) values of 0.04-0.06, 0.02-0.50, 0.01-0.12, 0.10-0.27, and 0.02-0.04 µg/mL, respectively. In addition, the Annona crassiflora and A. coriacea seed extracts were the most active among the tested extracts and the most effective against the tumor cell lines, with GI50 values below 8.90 µg/mL. The A. cacans extract displayed the lowest activity. Based on the microplate assay, the percent AchE inhibition of the extracts ranged from 12 to 52%, and the A. coriacea seed extract resulted in the greatest inhibition (52%). Caffeic acid, sinapic acid, and rutin were present at higher concentrations in the A. crassiflora seed samples. The A. coriacea seeds contained ferulic and sinapic acid. Overall, the results indicated that A. crassiflora and A. coriacea extracts have antiproliferative and anticholinesterase properties, which opens up new possibilities for alternative pharmacotherapy drugs.
Resumo:
The microbiological quality of beef and meat products is strongly influenced by the conditions of hygiene prevailing during their production and handling. Without proper hygienic control, the environment in slaughterhouses and butcher shops can act as an important source of microbiological contamination. To identify the main points of microbiological contamination in the beef processing chain, 443 samples of equipment, installations and products were collected from 11 establishments (1 slaughterhouse and 10 butcher shops) located in the state of Paraná, Brazil. The microbiological quality of all the samples was evaluated using Petri dishes to obtain counts of mesophilic aerobes (AC), total coliforms, Escherichia coli (EC), yeasts and molds (YM). The main contamination points identified in butcher shops, in decreasing order, were stainless steel boxes, beef tenderizers, grinders, knives, mixers, sausage stuffers, plastic boxes, floors and drains. In the slaughterhouse, these points were sausage stuffers, platforms, floors and drains. The most severely contaminated products were fresh sausages and ground beef. This information about the main points of microbiological contamination in the beef processing chain is expected to aid professionals responsible for hygiene in similar establishments to set up proper hygienic procedures to prevent or reduce microbiological contamination of beef and meat products.
Resumo:
Two flavors of cookies were developed (savory and peppery) containing a mixture of plants such as "guaraná" (Paullinia cupana) and "catuaba" (Anemopaegma mirandum). A test of acceptance and buying intention was applied to 48 consumers through a structured hedonic scale of 9 points. Afterwards, the centesimal compositions of these cookies were obtained as well as their total contents of copper, iron, and zinc through the method of atomic absorption spectrometry with flame. Sensorial tests indicated that the cookies presented good acceptance with potential to sensorial growth. The amount of fibers in the samples, 3 g/100 g, surpassed expectations since the product was not invented with the intention of being a source of this nutrient. The total amount of copper (0.41 mg.100 g-1), iron (4.50 mg.100 g-1), and zinc (1.32 mg.100 g-1) was considered good. The cookies produced can be considered good sources of fibers, copper, iron, and zinc. Furthermore, they are beneficial to people affected by celiac disease because they lack gluten. They also present functional properties. In addition, the medicinal plants used are considered energetic.
Resumo:
Pisciculture is an economic activity that is steadily growing in the state of Parana, Brazil, and Nile tilapia (Oreochromis niloticus) is one of the widely cultivated species in this state. Tilapia is not only a very nutritious food, but also an important indicator of environmental contamination. This study aimed to verify contamination by cadmium, copper and lead in tilapia fillets, and to compare the found values to international legislations. Were collected 135 samples of tilapia fillets, between July 2006 and May 2007, in three fish stores located in regions west and north of Paraná State. Samples of tilapia fillet were analyzed in relation to the presence of cadmiun, lead and copper, using atomic absorption spectrophotometry. Lead has not been detected in the analyses. Cadmium has been detected in three samples, on concentrations of 0.012 µg.g-1, 0.011 µg.g-1 and 0.014 µg.g-1. Copper has been detected in all fillets, and the average concentration of each cold storage plant was of 0.122 µg.g-1, 0.106 µg.g-1 and 0.153 µg.g-1. The concentrations found in this study are within the limits allowed by both the European and the Australian legislations.
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This thesis reviews the role of nuclear and conventional power plants in the future energy system. The review is done by utilizing freely accesible publications in addition to generating load duration and ramping curves for Nordic energy system. As the aim of the future energy system is to reduce GHG-emissions and avoid further global warming, the need for flexible power generation increases with the increased share of intermittent renewables. The goal of this thesis is to offer extensive understanding of possibilities and restrictions that nuclear power and conventional power plants have regarding flexible and sustainable generation. As a conclusion, nuclear power is the only technology that is able to provide large scale GHG-free power output variations with good ramping values. Most of the currently operating plants are able to take part in load following as the requirement to do so is already required to be included in the plant design. Load duration and ramping curves produced prove that nuclear power is able to cover most of the annual generation variation and ramping needs in the Nordic energy system. From the conventional power generation methods, only biomass combustion can be considered GHG-free because biomass is considered carbon neutral. CFB combusted biomass has good load follow capabilities in good ramping and turndown ratios. All the other conventional power generation technologies generate GHG-emissions and therefore the use of these technologies should be reduced.
Resumo:
Bidirectional exchange of information between the cancer cells and their environment is essential for cancer to evolve. Cancer cells lose the ability to regulate their growth, gain the ability to detach from neighboring cells and finally some of the cells disseminate from the primary tumor and invade to the adjacent tissue. During cancer progression, cells acquire features that promote cancer motility and proliferation one of them being increased filopodia number. Filopodia are dynamic actin-rich structures extending from the leading edge of migrating cells and the main function of these structures is to serve as environmental sensors. It is nowadays widely appreciated, that not only the cancer cells, but also the surrounding of the tumor – the tumor microenvironment- contribute to cancer cell dissemination and tumor growth. Activated stromal fibroblasts, also known as cancer-associated fibroblasts (CAFs) actively participate on tumor progression. CAFs are the most abundant cell type surrounding the cancer cells and they are the main cell type producing the extracellular matrix (ECM) within tumor stroma. CAFs secrete growth factors to promote tumor growth, direct cancer cell invasion as well as modify the stromal ECM architecture. The aim of this thesis was to investigate the function of filopodia, particularly the role of filopodia-inducing protein Myosin-X (Myo10), in breast cancer cell invasion and metastasis. We found that Myo10 is an important regulator of basal type breast cancer spreading downstream of mutant p53. In addition, I investigated the role of CAFs and their secreted matrix on tumor growth. According to the results, CAF-derived matrix has altered organization and stiffness which induces the carcinoma cell proliferation via epigenetic mechanisms. I identified histone demethylase enzyme JMJD1a to be regulated by the stiffness and to participate in stiffness induced growth control.
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The purpose of this master’s thesis is to gain an understanding of passive safety systems’ role in modern nuclear reactors projects and to research the failure modes of passive decay heat removal safety systems which use phenomenon of natural circulation. Another purpose is to identify the main physical principles and phenomena which are used to establish passive safety tools in nuclear power plants. The work describes passive decay heat removal systems used in AES-2006 project and focuses on the behavior of SPOT PG system. The descriptions of the main large-scale research facilities of the passive safety systems of the AES-2006 power plant are also included. The work contains the calculations of the SPOT PG system, which was modeled with thermal-hydraulic system code TRACE. The dimensions of the calculation model are set according to the dimensions of the real SPOT PG system. In these calculations three parameters are investigated as a function of decay heat power: the pressure of the system, the natural circulation mass flow rate around the closed loop, and the level of liquid in the downcomer. The purpose of the calculations is to test the ability of the SPOT PG system to remove the decay heat from the primary side of the nuclear reactor in case of failure of one, two, or three loops out of four. The calculations show that three loops of the SPOT PG system have adequate capacity to provide the necessary level of safety. In conclusion, the work supports the view that passive systems could be widely spread in modern nuclear projects.