462 research outputs found
A model for predicting organic compounds concentration change in water associated with horizontal hydraulic fracturing.
Predictive quantification of the concen- tration of organics in the produced water. The model satisfactorily fits the experi- mental data. Model is a valuable tool to forecast the contamination source term in the flowback. The model could serve as a tool to im- prove the monitoring strategy
A Novel Extracytoplasmic Function (ECF) Sigma Factor Regulates Virulence in Pseudomonas aeruginosa
Next to the two-component and quorum sensing systems, cell-surface signaling (CSS) has been recently identified as an important regulatory system in Pseudomonas aeruginosa. CSS systems sense signals from outside the cell and transmit them into the cytoplasm. They generally consist of a TonB-dependent outer membrane receptor, a sigma factor regulator (or anti-sigma factor) in the cytoplasmic membrane, and an extracytoplasmic function (ECF) sigma factor. Upon perception of the extracellular signal by the receptor the ECF sigma factor is activated and promotes the transcription of a specific set of gene(s). Although most P. aeruginosa CSS systems are involved in the regulation of iron uptake, we have identified a novel system involved in the regulation of virulence. This CSS system, which has been designated PUMA3, has a number of unusual characteristics. The most obvious difference is the receptor component which is considerably smaller than that of other CSS outer membrane receptors and lacks a β-barrel domain. Homology modeling of PA0674 shows that this receptor is predicted to be a bilobal protein, with an N-terminal domain that resembles the N-terminal periplasmic signaling domain of CSS receptors, and a C-terminal domain that resembles the periplasmic C-terminal domains of the TolA/TonB proteins. Furthermore, the sigma factor regulator both inhibits the function of the ECF sigma factor and is required for its activity. By microarray analysis we show that PUMA3 regulates the expression of a number of genes encoding potential virulence factors, including a two-partner secretion (TPS) system. Using zebrafish (Danio rerio) embryos as a host we have demonstrated that the P. aeruginosa PUMA3-induced strain is more virulent than the wild-type. PUMA3 represents the first CSS system dedicated to the transcriptional activation of virulence functions in a human pathogen
Gitools: Analysis and Visualisation of Genomic Data Using Interactive Heat-Maps
Intuitive visualization of data and results is very important in genomics, especially when many conditions are to be analyzed and compared. Heat-maps have proven very useful for the representation of biological data. Here we present Gitools (http://www.gitools.org), an open-source tool to perform analyses and visualize data and results as interactive heat-maps. Gitools contains data import systems from several sources (i.e. IntOGen, Biomart, KEGG, Gene Ontology), which facilitate the integration of novel data with previous knowledge
Stereoselective Ag-Catalyzed 1,3-Dipolar Cycloaddition of Activated Trifluoromethyl-Substituted Azomethine Ylides
This is the peer reviewed version of the following article: Chemistry – A European Journal 22.14 (2016): 4952 - 4959, which has been published in final form at http://doi.org/10.1002/chem.201504869. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsA silver-catalyzed 1,3-dipolar cycloaddition of fluorinated azomethine ylides and activated olefins is reported. The reaction offers a straightforward and atom-economical procedure for the preparation of fluorinated pyrrolidines. Broad scope and high levels of diastereoselectivity have been achieved simply by using AgOAc/PPh3as the catalyst system. The high efficiency of the cycloaddition relies on the presence of a metal-coordinating group on the imine moiety, such as an ester or heteroaryl group. The asymmetric version of the cycloaddition has been developed by using Taniaphos as a chiral ligandFinancial support of this work by the Ministerio de Economía y
Competitividad (MINECO, CTQ2012-35790) is gratefully
acknowledge
Effects of dietary supplementation of nickel and nickel-zinc on femoral bone structure in rabbits
<p>Abstract</p> <p>Background</p> <p>Nickel (Ni) and zinc (Zn) are trace elements present at low concentrations in agroecosystems. Nickel, however, may have toxic effects on living organisms and is often considered as a contaminant. This study reports the effect of peroral administrated Ni or a combination of Ni and Zn on femoral bone structure in rabbits.</p> <p>Methods</p> <p>One month-old female rabbits were divided into three groups of five animals each. Group 1 rabbits were fed a granular feed mixture with addition of 35 g NiCl<sub>2 </sub>per 100 kg of mixture for 90 days. In group 2, animals were fed a mixture containing 35 g NiCl<sub>2 </sub>and 30 g ZnCl<sub>2 </sub>per 100 kg of mixture. Group 3 without administration of additional Ni or Zn served as control. After the 90-day experimental period, femoral length, femoral weight and histological structure of the femur were analyzed and compared.</p> <p>Results</p> <p>The results did not indicate a statistically significant difference in either femoral length or weight between the two experimental groups and the control group. Also, differences in qualitative histological characteristics of the femora among rabbits from the three groups were absent, except for a fewer number of secondary osteons found in the animals of groups 1 and 2. However, values for vascular canal parameters of primary osteons were significantly lower in group 1 than in the control one. Peroral administration of a combination of Ni and Zn (group 2) led to a significant decreased size of the secondary osteons.</p> <p>Conclusions</p> <p>The study indicates that dietary supplementation of Ni (35 g NiCl<sub>2 </sub>per 100 kg of feed mixture) and Ni-Zn combination (35 g NiCl<sub>2 </sub>and 30 g ZnCl<sub>2 </sub>per 100 kg of the mixture) affects the microstructure of compact bone tissue in young rabbits.</p
Effectiveness of a cognitive behavioral intervention in patients with medically unexplained symptoms: cluster randomized trial
BACKGROUND: Medically unexplained symptoms are an important mental health problem in primary care and generate a high cost in health services.Cognitive behavioral therapy and psychodynamic therapy have proven effective in these patients. However, there are few studies on the effectiveness of psychosocial interventions by primary health care. The project aims to determine whether a cognitive-behavioral group intervention in patients with medically unexplained symptoms, is more effective than routine clinical practice to improve the quality of life measured by the SF-12 questionary at 12 month. METHODS/DESIGN: This study involves a community based cluster randomized trial in primary healthcare centres in Madrid (Spain). The number of patients required is 242 (121 in each arm), all between 18 and 65 of age with medically unexplained symptoms that had seeked medical attention in primary care at least 10 times during the previous year. The main outcome variable is the quality of life measured by the SF-12 questionnaire on Mental Healthcare. Secondary outcome variables include number of consultations, number of drug (prescriptions) and number of days of sick leave together with other prognosis and descriptive variables. Main effectiveness will be analyzed by comparing the percentage of patients that improve at least 4 points on the SF-12 questionnaire between intervention and control groups at 12 months. All statistical tests will be performed with intention to treat. Logistic regression with random effects will be used to adjust for prognostic factors. Confounding factors or factors that might alter the effect recorded will be taken into account in this analysis. DISCUSSION: This study aims to provide more insight to address medically unexplained symptoms, highly prevalent in primary care, from a quantitative methodology. It involves intervention group conducted by previously trained nursing staff to diminish the progression to the chronicity of the symptoms, improve quality of life, and reduce frequency of medical consultations. TRIAL REGISTRATION: The trial was registered with ClinicalTrials.gov, number NCT01484223 [http://ClinicalTrials.gov].S
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