3,214 research outputs found

    BORAZANs:  Tunable Fluorophores Based on 2-(Pyrazolyl)aniline Chelates of Diphenylboron

    Get PDF
    The reaction between 2-pyrazolyl-4-X-anilines, H(pzAnX), (X = para-OMe (L1), Me (L2), H (L3), Cl (L4), CO2Et (L5), CF3 (L6), CN (L7)) and triphenylboron in boiling toluene affords the respective, highly emissive N,N‘-boron chelate complexes, BPh2(pzAnX) (X = para-OMe (1), Me (2), H (3), Cl (4), CO2Et (5), CF3 (6), CN (7)) in high yield. The structural, electrochemical, and photophysical properties of the new boron complexes can be fine-tuned by varying the electron-withdrawing or -donating power of the para-aniline substituent (delineated by the substituent\u27s Hammett parameter). Those complexes with electron-withdrawing para-aniline substituents such as CO2Et (5), CF3 (6), and CN (7) have more planar chelate rings, more ‘quinoidal\u27 disortion in the aniline rings, greater chemical stability, higher oxidation potentials, and more intense (φF = 0.81 for 7 in toluene), higher-energy (blue) fluorescent emission compared to those with electron-donating substituents. Thus, for 1 the oxidation potential is 0.53 V versus Ag/AgCl (compared to 1.12 V for 7), and the emission is tuned to the yellow-green but at an expense in terms of lower quantum yields (φF = 0.07 for 1 in toluene) and increased chemical reactivity. Density functional calculations (B3LYP/6-31G*) on PM3 energy-minimized structures of the ligands and boron complexes reproduced experimentally observed data and trends and provided further insight into the nature of the electronic transitions

    Challenges of nematode control in ruminants : focus on Latin America

    Get PDF
    AbstractGastrointestinal nematodes (GIN) of ruminants (cattle, sheep and goats) are ubiquitous and can cause severe injuries to infected animals and significant losses in farming revenues. GIN are able to survive severe environmental and host conditions, but mankind has developed a number of ingenious methods for parasite control. The commerce and use of modern anthelmintic drugs with a broad spectrum of activity has been a solid tool for nearly 40 years, however the continuous use of these drugs, has led to the selection of populations of drug-resistant worms worldwide. At present, the ever-growing agricultural systems in Latin America are facing many challenges and cannot rely on the far-reaching objective of parasitic elimination from the host or the environment. The lack of extensive programs for monitoring drug resistance exacerbates the negative consequences of reduced efficacy, which is evident in some areas with the increase in mortality rate even after treatment. Experts agree that new schemes of parasitic control are needed and should be based on the strategy of targeted selective treatment where affected hosts are identified and treated accordingly. In this article, we will focus our discussion on the challenges for the control of GIN in Latin America by 2020 imposed by reduced drug efficacy. We will evaluate phenotypic and molecular markers, methods for single-animal evaluation, and the implementation of schemes for anthelmintic treatment that address parasites in refugia

    Identification of hazardous nanoparticles present in the Caribbean Sea for the allocation of future preservation projects

    Get PDF
    The deposition of remaining nanoparticles in the Caribbean Sea generates the formation of potentially dangerous elements, which influence at the imbalance of ecosystems. The detection of nanoparticles is not simple and the use of conventional methods is difficult application, which is why we highlight the immediacy and importance of this research for the areas of marine biology, urbanism, engineering and geosciences, applied in the Caribbean Sea. The general objective of this study is to evaluate the use of advanced methods for the determination of toxic nanoparticles, which can directly affect the development of marine organisms in the aquatic ecosystem in waters of the Caribbean Sea, favoring the construction of future international public policies with the elaboration of projects capable of mitigating these levels of contamination. The morphology and structure of nanoparticles were analyzed by emission scanning electron microscope with a high-resolution electron microscope. The nanoparticles smaller than 97 nm were identified in different proportions. The morphological analyses indicated nanoparticles' presence in the form of nanotubes, nanospheres, and nanofibers, which were shown in an agglomerated form. The presence of potentially hazardous elements, such as As, Cd, Pb, Mg, Ni and V were verified. In addition, the presence of asbestos in the form of minerals was confirmed, and that of titanium dioxide was found in large quantities. The results provide new data and emphasize the possible consequences to the in the Caribbean Sea, with the identification of dangerous elements (As, Cb, Pb, Hg, Ni and V), harmful to the marine ecosystem. Therefore, there is a need for strict control to reduce contamination of the Caribbean Sea and avoid risks to the ecosystem and public health, through suggestions of international public policies, through constant monitoring and the application of environmental recovery projects in this marine estuary

    Optimizing Phase Settings of High-Frequency Voltage Regulators for Power Delivery Applications

    Get PDF
    Every new computer server introduced to the market aims at delivering the best tradeoff between performance and power consumption. This goal is crucial in the case of servers for cloud computing hardware infrastructure. In this context, power delivery (PD) experts are adopting higher frequency switching voltage regulators (VR) to reduce platform’s cost as well as total cost of ownership (TCO). Because of this fact, the real estate of components, such as voltage regulators and output inductors, is shrinking as VR frequency increases. As a consequence, achieving the best performance of the VR implies looking into phase shedding schemes, as well as EM coupled inductor design, among other techniques, to mitigate power losses. This paper focuses on the study of the best angle arrangement possible for high frequency VR applications, by exploring angle settings under light load scenarios, aiming to minimize VR’s power loss and output’s voltage ripple

    SIMBA: a web tool for managing bacterial genome assembly generated by Ion PGM sequencing technology

    Get PDF
    Background The evolution of Next-Generation Sequencing (NGS) has considerably reduced the cost per sequenced-base, allowing a significant rise of sequencing projects, mainly in prokaryotes. However, the range of available NGS platforms requires different strategies and software to correctly assemble genomes. Different strategies are necessary to properly complete an assembly project, in addition to the installation or modification of various software. This requires users to have significant expertise in these software and command line scripting experience on Unix platforms, besides possessing the basic expertise on methodologies and techniques for genome assembly. These difficulties often delay the complete genome assembly projects. Results In order to overcome this, we developed SIMBA (SImple Manager for Bacterial Assemblies), a freely available web tool that integrates several component tools for assembling and finishing bacterial genomes. SIMBA provides a friendly and intuitive user interface so bioinformaticians, even with low computational expertise, can work under a centralized administrative control system of assemblies managed by the assembly center head. SIMBA guides the users to execute assembly process through simple and interactive pages. SIMBA workflow was divided in three modules: (i) projects: allows a general vision of genome sequencing projects, in addition to data quality analysis and data format conversions; (ii) assemblies: allows de novo assemblies with the software Mira, Minia, Newbler and SPAdes, also assembly quality validations using QUAST software; and (iii) curation: presents methods to finishing assemblies through tools for scaffolding contigs and close gaps. We also presented a case study that validated the efficacy of SIMBA to manage bacterial assemblies projects sequenced using Ion Torrent PGM. Conclusion Besides to be a web tool for genome assembly, SIMBA is a complete genome assemblies project management system, which can be useful for managing of several projects in laboratories. SIMBA source code is available to download and install in local webservers at http://ufmg-simba.sourceforge.net

    A new strategy for using banana as an ingredient in the brewing process

    Get PDF
    Beer is a traditionally fermented beverage made from malted grains of barley, hops, yeast, and water, while banana is an important food crop cultivated widely in tropical and subtropical areas and is one of the major fruits in Brazil. Besides, the banana is also very favorable to food industry (e.g. fermented beverages) due to its rich content on soluble solids, presence of minerals, and providing low acidity. In this context, the objective of this work was to evaluate a new strategy for using banana as adjunct to increase the fermentable sugars and to supply a specific aroma in pilot-plant brewing experiments. For this, static fermentations were conducted in a 180 L cylindrical-conical reactor using 140 L as working volume. Addition of banana was evaluated when changing the concentration of the wort from 10 to 12 ºP and from 10 to 13.5 ºP (ºP is the weight of the extract or the sugar equivalent in 100 g solution, at 20 ºC) and fermented under a constant temperature of 10 and 12.5 ºC, respectively. The results showed that the increment in the initial sugar concentration (12 to 13.5 ºP, due to the use of banana juice as adjunct), and in the temperature (10 to 12.5 ºC), increased approximately 17% the ethanol productivity. Thus, it was concluded that by using of simple preparation techniques of banana juice, banana can be used as adjunct in brewing processes, helping in the development of new products as well as in the elaboration of more concentrated worts when compared the traditional brewing worts.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Malteria do ValeCorn Products BrasilWallerstein Industrial e ComercialDiverseyLever (Brazil)Fundação para a Ciência e a Tecnologia (FCT)CAPES/GRICES (Brazil/Portugal

    A IMPORTÂNCIA DA CONTABILIDADE DE CUSTOS NA FORMAÇÃO DO PREÇO DE VENDA

    Get PDF

    IKKβ kinase promotes stemness, migration, and invasion in KRAS-driven lung adenocarcinoma cells

    Get PDF
    KRAS oncogenic mutations are widespread in lung cancer and, because direct targeting of KRAS has proven to be challenging, KRAS-driven cancers lack effective therapies. One alternative strategy for developing KRAS targeted therapies is to identify downstream targets involved in promoting important malignant features, such as the acquisition of a cancer stem-like and metastatic phenotype. Based on previous studies showing that KRAS activates nuclear factor kappa-B (NF-κB) through inhibitor of nuclear factor kappa-B kinase β (IKKβ) to promote lung tumourigenesis, we hypothesized that inhibition of IKKβ would reduce stemness, migration and invasion of KRAS-mutant human lung cancer cells. We show that KRAS-driven lung tumoursphere-derived cells exhibit stemness features and increased IKKβ kinase activity. IKKβ targeting by different approaches reduces the expression of stemness-associated genes, tumoursphere formation, and self-renewal, and preferentially impairs the proliferation of KRAS-driven lung tumoursphere-derived cells. Moreover, we show that IKKβ targeting reduces tumour cell migration and invasion, potentially by regulating both expression and activity of matrix metalloproteinase 2 (MMP2). In conclusion, our results indicate that IKKβ is an important mediator of KRAS-induced stemness and invasive features in lung cancer, and, therefore, might constitute a promising strategy to lower recurrence rates, reduce metastatic dissemination, and improve survival of lung cancer patients with KRAS-driven disease

    Efeitos dos esteróides sexuais sobre o humor e a cognição

    Get PDF
    The results of several experimental and observational studies suggest that sexual steroids present effects on central nervous system and potentially may affect mood and cognition. The use of estrogens in pre and postmenopausal period is associated to improvement of concentration, mood, memory and sleep pattern. Estrogens are also is associated to a delay in cognitive function decline characteristic of aging process or to the onset of Alzheimer disease. The observational studies indicate that estrogens may improve the mood and act as antidpressive but progesterone and its derivatives have opposite effect. However, randomized controlled trials suggest that the estrogen or estrogen plus progestins not only failed to improove mood, cognition na quality of life but also increase the risk of dementia. Therefore, there is a contradiction between observational and controlled randomized studies. Further investigations must to be done in order to clarify this controversy. However, up to now the data indicate that estrogen therapy is not to be primarily indicated to prevent depression, Alzheimer disease or cognition impairment.Estudos experimentais e observacionais sugerem que os esteróides sexuais apresentam uma série de efeitos sobre o cérebro e que, potencialmente, afetam a cognição e o humor. O uso dos estrogênios na peri e pós-menopausa está associado à melhora da concentração, humor, memória e sono. Está também associado a retardo no declínio da função cognitiva, característico do envelhecimento, e os dados sugerem também um papel dos estrogênios no retardo do início da doença de Alzheimer. Vários estudos observacionais indicam, ainda, que os estrogênios atuam melhorando o humor e têm ação antidepressiva. Já a progesterona e seus derivados têm mostrado efeitos opostos aos dos estrogênios. Por outro lado, dados de estudos randomizados e controlados mostraram que a associação de estrogênios mais progestagênios utilizados em mulheres na pós-menopausa não só falhou em melhorar a memória, cognição e qualidade de vida, mas também aumentou o risco de demência, portanto contradisse os estudos observacionais e experimentais. Novas pesquisas serão necessárias para esclarecer essas controvérsias. Os dados disponíveis até o momento indicam que não se deve prescrever primariamente a estrogenioterapia para prevenir depressão, doença de Alzheimer ou piora da função cognitiva

    Splicing Factors in Breast Cancer: Drivers of the Breast Tumor Fate

    Get PDF
    Splicing is a critical step in gene expression, responsible for the excision of introns, producing the mature form of mRNA. Also, the possible arrangements of exons enlarge the proteome in 80%, enabling one gene to encode more than one protein isoform, thus increasing proteome. Growing data show deregulation of splicing events in cancer, being breast cancer the most studied. This aberrant pattern of splicing has an important role in breast tumor progression. These alterations are mainly caused by misexpression of some critical alternative splicing factors. The behavior of these splicing factors is implicated with important clinical features, such as chemoresistance, aggressiveness, and also metastases. In this chapter, the role of five splicing factors is discussed in the light of relevant data about in vitro, in vivo, and ex vivo studies to construct a representative scheme of their behavior in breast cancer progression. Although the presented five splicing factors have important role in breast cancer, only three of them (ESRP1, RBFOX2, and SRSF1) have a more prominent role in tumorigenesis and tumor progression. These concepts will elucidate their role in tumorigenesis and a prospective use as biomarkers in breast cancer
    corecore