52 resultados para Commonly used


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Background Enzymatic biodiesel is becoming an increasingly popular topic in bioenergy literature because of its potential to overcome the problems posed by chemical processes. However, the high cost of the enzymatic process still remains the main drawback for its industrial application, mostly because of the high price of refined oils. Unfortunately, low cost substrates, such as crude soybean oil, often release a product that hardly accomplishes the final required biodiesel specifications and need an additional pretreatment for gums removal. In order to reduce costs and to make the enzymatic process more efficient, we developed an innovative system for enzymatic biodiesel production involving a combination of a lipase and two phospholipases. This allows performing the enzymatic degumming and transesterification in a single step, using crude soybean oil as feedstock, and converting part of the phospholipids into biodiesel. Since the two processes have never been studied together, an accurate analysis of the different reaction components and conditions was carried out. Results Crude soybean oil, used as low cost feedstock, is characterized by a high content of phospholipids (900 ppm of phosphorus). However, after the combined activity of different phospholipases and liquid lipase Callera Trans L, a complete transformation into fatty acid methyl esters (FAMEs >95%) and a good reduction of phosphorus (P <5 ppm) was achieved. The combination of enzymes allowed avoidance of the acid treatment required for gums removal, the consequent caustic neutralization, and the high temperature commonly used in degumming systems, making the overall process more eco-friendly and with higher yield. Once the conditions were established, the process was also tested with different vegetable oils with variable phosphorus contents. Conclusions Use of liquid lipase Callera Trans L in biodiesel production can provide numerous and sustainable benefits. Besides reducing the costs derived from enzyme immobilization, the lipase can be used in combination with other enzymes such as phospholipases for gums removal, thus allowing the use of much cheaper, non-refined oils. The possibility to perform degumming and transesterification in a single tank involves a great efficiency increase in the new era of enzymatic biodiesel production at industrial scale.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Leprosy is a contagious and chronic systemic granulomatous disease caused by Mycobacterium leprae (Hansen"s bacillus). It is transmitted from person to person and has a long incubation period (between two and six years). The disease presents polar clinical forms (the"multibacillary" lepromatous leprosy and the"paucibacillary" tuberculoid leprosy), as well as other intermediate forms with hybrid characteristics. Oral manifestations usually appear in lepromatous leprosy and occur in 20-60% of cases. They may take the form of multiple nodules (lepromas) that progress to necrosis and ulceration. The ulcers are slow to heal, and produce atrophic scarring or even tissue destruction. The lesions are usually located on the hard and soft palate, in the uvula, on the underside of the tongue, and on the lips and gums. There may also be destruction of the anterior maxilla and loss of teeth. The diagnosis, based on clinical suspicion, is confirmed through bacteriological and histopathological analyses, as well as by means of the lepromin test (intradermal reaction that is usually negative in lepromatous leprosy form and positive in the tuberculoid form). The differential diagnosis includes systemic lupus erythematosus, sarcoidosis, cutaneous leishmaniasis and other skin diseases, tertiary syphilis, lymphomas, systemic mycosis, traumatic lesions and malignant neoplasias, among other disorders. Treatment is difficult as it must be continued for long periods, requires several drugs with adverse effects and proves very expensive, particularly for less developed countries. The most commonly used drugs are dapsone, rifampicin and clofazimine. Quinolones, such as ofloxacin and pefloxacin, as well as some macrolides, such as clarithromycin and minocyclin, are also effective. The present case report describes a patient with lepromatous leprosy acquired within a contagious family setting during childhood and adolescence

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Complex psychopathological and behavioral symptoms, such as delusions and aggression against care providers, are often the primary cause of acute hospital admissions of elderly patients to emergency units and psychiatric departments. This issue resembles an interdisciplinary clinically highly relevant diagnostic and therapeutic challenge across many medical subjects and general practice. At least 50% of the dramatically growing number of patients with dementia exerts aggressive and agitated symptoms during the course of clinical progression, particularly at moderate clinical severity. METHODS: Commonly used rating scales for agitation and aggression are reviewed and discussed. Furthermore, we focus in this article on benefits and limitations of all available data of anticonvulsants published in this specific indication, such as valproate, carbamazepine, oxcarbazepine, lamotrigine, gabapentin and topiramate. RESULTS: To date, most positive and robust data are available for carbamazepine, however, pharmacokinetic interactions with secondary enzyme induction limit its use. Controlled data of valproate do not seem to support the use in this population. For oxcarbazepine only one controlled but negative trial is available. Positive small series and case reports have been reported for lamotrigine, gabapentin and topiramate. CONCLUSION: So far, data of anticonvulsants in demented patients with behavioral disturbances are not convincing. Controlled clinical trials using specific, valid and psychometrically sound instruments of newer anticonvulsants with a better tolerability profile are mandatory to verify whether they can contribute as treatment option in this indication.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Several approaches have been developed to estimate both the relative and absolute rates of speciation and extinction within clades based on molecular phylogenetic reconstructions of evolutionary relationships, according to an underlying model of diversification. However, the macroevolutionary models established for eukaryotes have scarcely been used with prokaryotes. We have investigated the rate and pattern of cladogenesis in the genus Aeromonas (γ-Proteobacteria, Proteobacteria, Bacteria) using the sequences of five housekeeping genes and an uncorrelated relaxed-clock approach. To our knowledge, until now this analysis has never been applied to all the species described in a bacterial genus and thus opens up the possibility of establishing models of speciation from sequence data commonly used in phylogenetic studies of prokaryotes. Our results suggest that the genus Aeromonas began to diverge between 248 and 266 million years ago, exhibiting a constant divergence rate through the Phanerozoic, which could be described as a pure birth process.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Complex psychopathological and behavioral symptoms, such as delusions and aggression against care providers, are often the primary cause of acute hospital admissions of elderly patients to emergency units and psychiatric departments. This issue resembles an interdisciplinary clinically highly relevant diagnostic and therapeutic challenge across many medical subjects and general practice. At least 50% of the dramatically growing number of patients with dementia exerts aggressive and agitated symptoms during the course of clinical progression, particularly at moderate clinical severity. METHODS: Commonly used rating scales for agitation and aggression are reviewed and discussed. Furthermore, we focus in this article on benefits and limitations of all available data of anticonvulsants published in this specific indication, such as valproate, carbamazepine, oxcarbazepine, lamotrigine, gabapentin and topiramate. RESULTS: To date, most positive and robust data are available for carbamazepine, however, pharmacokinetic interactions with secondary enzyme induction limit its use. Controlled data of valproate do not seem to support the use in this population. For oxcarbazepine only one controlled but negative trial is available. Positive small series and case reports have been reported for lamotrigine, gabapentin and topiramate. CONCLUSION: So far, data of anticonvulsants in demented patients with behavioral disturbances are not convincing. Controlled clinical trials using specific, valid and psychometrically sound instruments of newer anticonvulsants with a better tolerability profile are mandatory to verify whether they can contribute as treatment option in this indication.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Todavía sabemos poco sobre las formas de adopción, o rechazo, de la comunicación móvil por parte de las personas adultas mayores. ¿De qué manera utilizan la telefonía móvil? ¿Cuáles son los motivos de rechazo de este tipo de telefonía, si los hay?Discutimos los resultados de un caso de estudio cualitativo con personas adultas mayores (60 años o más), desarrollado en el área metropolitana de Montevideo en 2012. Los y las participantes valoran la conectividad permanente que brinda el teléfono móvil. Lo utilizan en combinación con otros canales, como el teléfono fijo, para una diversidad de objetivos y con diferentes interlocutores. Además de las llamadas de voz, los SMS son de uso habitual. Entre los no usuarios encontramos tanto el discurso del rechazo como el de la indiferencia hacia el celular. Finalmente, todos los usuarios de Internet son, también, usuarios de teléfono celular.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Forecasting coal resources and reserves is critical for coal mine development. Thickness maps are commonly used for assessing coal resources and reserves; however they are limited for capturing coal splitting effects in thick and heterogeneous coal zones. As an alternative, three-dimensional geostatistical methods are used to populate facies distributionwithin a densely drilled heterogeneous coal zone in the As Pontes Basin (NWSpain). Coal distribution in this zone is mainly characterized by coal-dominated areas in the central parts of the basin interfingering with terrigenous-dominated alluvial fan zones at the margins. The three-dimensional models obtained are applied to forecast coal resources and reserves. Predictions using subsets of the entire dataset are also generated to understand the performance of methods under limited data constraints. Three-dimensional facies interpolation methods tend to overestimate coal resources and reserves due to interpolation smoothing. Facies simulation methods yield similar resource predictions than conventional thickness map approximations. Reserves predicted by facies simulation methods are mainly influenced by: a) the specific coal proportion threshold used to determine if a block can be recovered or not, and b) the capability of the modelling strategy to reproduce areal trends in coal proportions and splitting between coal-dominated and terrigenousdominated areas of the basin. Reserves predictions differ between the simulation methods, even with dense conditioning datasets. Simulation methods can be ranked according to the correlation of their outputs with predictions from the directly interpolated coal proportion maps: a) with low-density datasets sequential indicator simulation with trends yields the best correlation, b) with high-density datasets sequential indicator simulation with post-processing yields the best correlation, because the areal trends are provided implicitly by the dense conditioning data.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Both the intermolecular interaction energies and the geometries for M ̄ thiophene, M ̄ pyrrole, M n+ ̄ thiophene, and M n+ ̄ pyrrole ͑with M = Li, Na, K, Ca, and Mg; and M n+ = Li+ , Na+ , K+ , Ca2+, and Mg2+͒ have been estimated using four commonly used density functional theory ͑DFT͒ methods: B3LYP, B3PW91, PBE, and MPW1PW91. Results have been compared to those provided by HF, MP2, and MP4 conventional ab initio methods. The PBE and MPW1PW91 are the only DFT methods able to provide a reasonable description of the M ̄ complexes. Regarding M n+ ̄ ␲ complexes, the four DFT methods have been proven to be adequate in the prediction of these electrostatically stabilized systems, even though they tend to overestimate the interaction energies.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

VariScan is a software package for the analysis of DNA sequence polymorphisms at the whole genome scale. Among other features, the software:(1) can conduct many population genetic analyses; (2) incorporates a multiresolution wavelet transform-based method that allows capturing relevant information from DNA polymorphism data; and (3) it facilitates the visualization of the results in the most commonly used genome browsers.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

In this paper we provide a formal account for underapplication of vowel reduction to schwa in Majorcan Catalan loanwords and learned words. On the basis of the comparison of these data with those concerning productive derivation and verbal inflection, which show analogous patterns, in this paper we also explore the existing and not yet acknowledged correlation between those processes that exhibit a particular behaviour in the loanword phonology with respect to the native phonology of the language, those processes that show lexical exceptions and those processes that underapply due to morphological reasons. In light of the analysis of the very same data and taking into account the aforementioned correlation, we show how there might exist a natural diachronic relation between two kinds of Optimality Theory constraints which are commonly used but, in principle, mutually exclusive: positional faithfulness and contextual markedness constraints. Overall, phonological productivity is proven to be crucial in three respects: first, as a context of the grammar, given that «underapplication» is systematically found in what we call the productive phonology of the dialect (including loanwords, learned words, productive derivation and verbal inflection); second, as a trigger or blocker of processes, in that the productivity or the lack of productivity of a specific process or constraint in the language is what explains whether it is challenged or not in any of the depicted situations, and, third, as a guiding principle which can explain the transition from the historical to the synchronic phonology of a linguistic variety.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Objective. To carry out a pharmacoeconomic analysis of Cyclamen europaeum (CE) in the management of acute rhinosinusitis (ARS) in Spain using data from the PROSINUS study. Study Design. This was a prospective observational study to compare the effectiveness and cost-effectiveness between therapies including CE vs. other therapies in the management of ARS. Methods. The study was carried out as a secondary analysis of the PROSINUS, combining healthcare resource use, productivity loses, and health outcomes from the observational study with costs representative of the Spanish Health System. Results. CE given as monotherapy appears to be more effective (cure rate) than other monotherapies (15.3% higher, p<0.05) and combination (10.3% higher, p<0.05) therapies. The addition of CE to other single-drug or combination therapies showed a statistically significant improvement in terms of cure rates when adding CE to 2-drug combinations (93.9% vs. 76.5%; p<0.05), and no significant effect when added to combinations of three or more drugs (81.1% vs. 79.8; NS). CE based therapies generally showed lower indirect costs, although only the comparison of CE alone vs. other monotherapies, with a net cost savings of 101 per patient, reached statistical significance (331 vs. 432 , p<0.05). In addition, CE-based therapies show lower cost per cured patient in all comparisons except when CE was used in combination with three or more other drugs. Conclusions. The use of Cyclamen europaeum may be associated to better clinical outcomes at no additional cost for the healthcare system, respect to treatments commonly used for ARS in clinical practice.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Several approaches have been developed to estimate both the relative and absolute rates of speciation and extinction within clades based on molecular phylogenetic reconstructions of evolutionary relationships, according to an underlying model of diversification. However, the macroevolutionary models established for eukaryotes have scarcely been used with prokaryotes. We have investigated the rate and pattern of cladogenesis in the genus Aeromonas (γ-Proteobacteria, Proteobacteria, Bacteria) using the sequences of five housekeeping genes and an uncorrelated relaxed-clock approach. To our knowledge, until now this analysis has never been applied to all the species described in a bacterial genus and thus opens up the possibility of establishing models of speciation from sequence data commonly used in phylogenetic studies of prokaryotes. Our results suggest that the genus Aeromonas began to diverge between 248 and 266 million years ago, exhibiting a constant divergence rate through the Phanerozoic, which could be described as a pure birth process.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Leprosy is a contagious and chronic systemic granulomatous disease caused by Mycobacterium leprae (Hansen"s bacillus). It is transmitted from person to person and has a long incubation period (between two and six years). The disease presents polar clinical forms (the"multibacillary" lepromatous leprosy and the"paucibacillary" tuberculoid leprosy), as well as other intermediate forms with hybrid characteristics. Oral manifestations usually appear in lepromatous leprosy and occur in 20-60% of cases. They may take the form of multiple nodules (lepromas) that progress to necrosis and ulceration. The ulcers are slow to heal, and produce atrophic scarring or even tissue destruction. The lesions are usually located on the hard and soft palate, in the uvula, on the underside of the tongue, and on the lips and gums. There may also be destruction of the anterior maxilla and loss of teeth. The diagnosis, based on clinical suspicion, is confirmed through bacteriological and histopathological analyses, as well as by means of the lepromin test (intradermal reaction that is usually negative in lepromatous leprosy form and positive in the tuberculoid form). The differential diagnosis includes systemic lupus erythematosus, sarcoidosis, cutaneous leishmaniasis and other skin diseases, tertiary syphilis, lymphomas, systemic mycosis, traumatic lesions and malignant neoplasias, among other disorders. Treatment is difficult as it must be continued for long periods, requires several drugs with adverse effects and proves very expensive, particularly for less developed countries. The most commonly used drugs are dapsone, rifampicin and clofazimine. Quinolones, such as ofloxacin and pefloxacin, as well as some macrolides, such as clarithromycin and minocyclin, are also effective. The present case report describes a patient with lepromatous leprosy acquired within a contagious family setting during childhood and adolescence

Relevância:

60.00% 60.00%

Publicador:

Resumo:

El aprendizaje combinado se define como la integración eficaz de dos componentes: la enseñanza presencial y la tecnología no presencial. Este modelo intenta generar un aprendizaje que influya positivamente en el alumno y que a su vez mejore la calidad de enseñanza y los costos destinados a ello. Es importante señalar que el papel que tiene el profesor y su implicación, así como el proceso de mediación pedagógica, son los elementos clave del proceso. Este artículo hace una revisión del estado del arte y describe el significado del aprendizaje combinado, sus posibilidades, sus características, así como las teorías del aprendizaje que intervienen en el modelo, y concluye hablando de las herramientas utilizadas en los entornos de aprendizaje.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Emitter spacings of 0.3 to 0.6 m are commonly used for subsurface drip irrigation (SDI) of corn on the deep, silt loam soils of the U.S. Great Plains. Subsurface drip irrigation emitter spacings of 0.3, 0.6, 0.9 and 1.2 m were examined for the resulting differences in soil water redistribution, corn grain yield, yield components, seasonal water use, and water productivity in a 4‐year field study (2005 through 2008) at the Kansas State University Northwest Research‐Extension Center, Colby, Kansas. The results indicate that there is increased preferential water movement along the dripline (parallel) as compared to perpendicular to the dripline and that this phenomenon partially compensates for wider emitter spacings in terms of soil water redistribution. Corn yield and water productivity (WP) were not significantly affected by the emitter spacing with application of a full irrigation regime