2,641 research outputs found

    Scour around marine foundations in layered sediments: a mathematical modelling approach

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    In order to improve the understanding of scour processes in layered conditions for offshore foundations, a laboratory study was conducted regarding equilibrium scour depth vs. time curve and its adjustment to hyperbolic and exponential/linear combined functions. The present paper provides a mathematical study describing a set of scour tests in order to clarify the scour depth evolution for complex, non-cohesive soil configurations

    Expression, purification and structural analysis of the Pyrococcus abyssi RNA binding protein PAB1135

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    <p>Abstract</p> <p>Background</p> <p>The gene coding for the uncharacterized protein PAB1135 in the archaeon <it>Pyrococcus abyssi </it>is in the same operon as the ribonuclease P (RNase P) subunit Rpp30.</p> <p>Findings</p> <p>Here we report the expression, purification and structural analysis of PAB1135. We analyzed the interaction of PAB1135 with RNA and show that it binds efficiently double-stranded RNAs in a non-sequence specific manner. We also performed molecular modeling of the PAB1135 structure using the crystal structure of the protein Af2318 from <it>Archaeoglobus fulgidus </it>(<ext-link ext-link-id="2OGK" ext-link-type="pdb">2OGK</ext-link>) as the template.</p> <p>Conclusions</p> <p>Comparison of this model has lead to the identification of a region in PAB1135 that could be involved in recognizing double-stranded RNA.</p

    Pseudoboehmite as a drug delivery system for acyclovir

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    Herpes simplex virus is among the most prevalent sexually transmitted infections. Acyclovir is a potent, selective inhibitor of herpes viruses and it is indicated for the treatment and management of recurrent cold sores on the lips and face, genital herpes, among other diseases. The problem of the oral bioavailability of acyclovir is limited because of the low permeability across the gastrointestinal membrane. The use of nanoparticles of pseudoboehmite as a drug delivery system in vitro assays is a promising approach to further the permeability of acyclovir release. Here we report the synthesis of high purity pseudoboehmite from aluminium nitrate and ammonium hydroxide containing nanoparticles, using the sol–gel method, as a drug delivery system to improve the systemic bioavailability of acyclovir. The presence of pseudoboehmite nanoparticles were verified by infrared spectroscopy, transmission electron microscopy, and X-ray diffraction techniques. In vivo tests were performed with Wistar rats to compare the release of acyclovir, with and without the addition of pseudoboehmite. The administration of acyclovir with the addition of pseudoboehmite increased the drug content by 4.6 times in the plasma of Wistar rats after 4 h administration. We determined that the toxicity of pseudoboehmite is low up to 10 mg/mL, in gel and the dried pseudoboehmite nanoparticles.The authors thank the Mackenzie Presbyterian University, Texas Tech University, Mack Pesquisa, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES), Cnpq, and FAPESP (grant 2010/19157-9 and grant 2017/22396-4) for the sponsorship to this project

    The Role of Sarcopenic Obesity in Cancer and Cardiovascular Disease: A Synthesis of the Evidence on Pathophysiological Aspects and Clinical Implications

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    Obesity is globally a serious public health concern and is associated with a high risk of cardiovascular disease (CVD) and various types of cancers. It is important to evaluate various types of obesity, such as visceral and sarcopenic obesity. The evidence on the associated risk of CVD, cancer and sarcopenic obesity, including pathophysiological aspects, occurrence, clinical implications and survival, needs further investigation. Sarcopenic obesity is a relatively new term. It is a clinical condition that primarily affects older adults. There are several endocrine-hormonal, metabolic and lifestyle aspects involved in the occurrence of sarcopenic obesity that affect pathophysiological aspects that, in turn, contribute to CVD and neoplasms. However, there is no available evidence on the role of sarcopenic obesity in the occurrence of CVD and cancer and its pathophysiological interplay. Therefore, this review aims to describe the pathophysiological aspects and the clinical and epidemiological evidence on the role of sarcopenic obesity related to the occurrence and mortality risk of various types of cancer and cardiovascular disease. This literature review highlights the need for further research on sarcopenic obesity to demonstrate the interrelation of these various associations

    Toxicity of copaiba extracts to armyworm (Spodoptera frugiperda)

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    The objective of this study was to evaluate the effects of methanolic extracts from leaves, peels, seeds and pulps from fruits of Copaifera langsdorffii on Spodoptera frugiperda. Extracts derived from leaves and fruit peels were more toxic to S. frugiperda than the others. Hence, they were added to the artificial diet and used in further experiments with the second instar larvae of the insect, which presented larval growth reduction, prolonged period of development, increased mortality, and lower fertility and fecundity of adults. Lower egg viability was also observed when the insect was treated with extracts of leaves and fruit peels in the larvae stage. Moreover, when subjected to ultrastructural analysis under a scanning electron microscope, such eggs showed abnormalities in the aeropylar and micropylar regions. Both extracts also increased the excretion of protein in the insect feces and inhibited trypsin activity in the in vitro test. Consequently, C. langsdorffii presents potential to be used in the development of new products to control the fall armyworm.Key words: Copaifera langsdorffii, natural products, trypsin inhibitor, botanical insecticide

    Oxidative stress in the brain and arterial hypertension

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    Universidade Federal de São Paulo, Dept Physiol, BR-04023060 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, BR-04023060 São Paulo, BrazilWeb of Scienc

    Process Monitoring of Moisture Content and Mass Transfer Rate in a Fluidised Bed with a Low Cost Inline MEMS NIR Sensor

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    Purpose The current trend for continuous drug product manufacturing requires new, affordable process analytical techniques (PAT) to ensure control of processing. This work evaluates whether property models based on spectral data from recent Fabry–Pérot Interferometer based NIR sensors can generate a high-resolution moisture signal suitable for process control. Methods Spectral data and offline moisture content were recorded for 14 fluid bed dryer batches of pharmaceutical granules. A PLS moisture model was constructed resulting in a high resolution moisture signal, used to demonstrate (i) endpoint determination and (ii) evaluation of mass transfer performance. Results The sensors appear robust with respect to vibration and ambient temperature changes, and the accuracy of water content predictions (±13 % ) is similar to those reported for high specification NIR sensors. Fusion of temperature and moisture content signal allowed monitoring of water transport rates in the fluidised bed and highlighted the importance water transport within the solid phase at low moisture levels. The NIR data was also successfully used with PCA-based MSPC models for endpoint detection. Conclusions The spectral quality of the small form factor NIR sensor and its robustness is clearly sufficient for the construction and application of PLS models as well as PCA-based MSPC moisture models. The resulting high resolution moisture content signal was successfully used for endpoint detection and monitoring the mass transfer rate

    Identification of archaeal proteins that affect the exosome function in vitro

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    <p>Abstract</p> <p>Background</p> <p>The archaeal exosome is formed by a hexameric RNase PH ring and three RNA binding subunits and has been shown to bind and degrade RNA <it>in vitro</it>. Despite extensive studies on the eukaryotic exosome and on the proteins interacting with this complex, little information is yet available on the identification and function of archaeal exosome regulatory factors.</p> <p>Results</p> <p>Here, we show that the proteins PaSBDS and PaNip7, which bind preferentially to poly-A and AU-rich RNAs, respectively, affect the <it>Pyrococcus abyssi </it>exosome activity <it>in vitro</it>. PaSBDS inhibits slightly degradation of a poly-rA substrate, while PaNip7 strongly inhibits the degradation of poly-A and poly-AU by the exosome. The exosome inhibition by PaNip7 appears to depend at least partially on its interaction with RNA, since mutants of PaNip7 that no longer bind RNA, inhibit the exosome less strongly. We also show that FITC-labeled PaNip7 associates with the exosome in the absence of substrate RNA.</p> <p>Conclusions</p> <p>Given the high structural homology between the archaeal and eukaryotic proteins, the effect of archaeal Nip7 and SBDS on the exosome provides a model for an evolutionarily conserved exosome control mechanism.</p
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