982 resultados para ESSENTIAL SPECTRUM OF SEMIGROUP
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2000 Mathematics Subject Classification: 47A10, 47A13.
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2010 Mathematics Subject Classification: 47A10.
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Antibiotic resistance, production of alginate and virulence factors, and altered host immune responses are the hallmarks of chronic Pseudomonas aeruginosa infection. Failure of antibiotic therapy has been attributed to the emergence of P. aeruginosa strains that produce β-lactamase constitutively. In Enterobacteriaceae, β-lactamase induction involves four genes with known functions: ampC, ampR, ampD, and ampG, encoding the enzyme, transcriptional regulator, amidase and permease, respectively. In addition to all these amp genes, P. aeruginosa possesses two ampG paralogs, designated ampG and ampP. In this study, P. aeruginosa ampC, ampR, ampG and ampP were analyzed. Inactivation of ampC in the prototypic PAO1 failed to abolish the β-lactamase activity leading to the discovery of P. aeruginosa oxacillinase PoxB. Cloning and expression of poxB in Escherichia coli confers β-lactam resistance. Both AmpC and PoxB contribute to P. aeruginosa resistance against a wide spectrum of β-lactam antibiotics. The expression of PoxB and AmpC is regulated by a LysR-type transcriptional regulator AmpR that up-regulates AmpC but down-regulates PoxB activities. Analyses of P. aeruginosa ampR mutant demonstrate that AmpR is a global regulator that modulates the expressions of Las and Rhl quorum sensing (QS) systems, and the production of pyocyanin, LasA protease and LasB elastase. Introduction of the ampR mutation into an alginate-producing strain reveals the presence of a complex co-regulatory network between antibiotic resistance, QS alginate and other virulence factor production. Using phoA and lacZ protein fusion analyses, AmpR, AmpG and AmpP were localized to the inner membrane with one, 16 and 10 transmembrane helices, respectively. AmpR has a cytoplasmic DNA-binding and a periplasmic substrate binding domains. AmpG and AmpP are essential for the maximal expression of β-lactamase. Analysis of the murein breakdown products suggests that AmpG exports UDP-N-acetylmuramyl-L-alanine-γ-D-glutamate-meso-diaminopimelic acid-D-alanine-D-alanine (UDP-MurNAc-pentapeptide), the corepressor of AmpR, whereas AmpP imports N-acetylglucosaminyl-beta-1,4-anhydro-N-acetylmuramic acid-Ala-γ-D-Glu-meso-diaminopimelic acid (GlcNAc-anhMurNAc-tripeptide) and GlcNAc-anhMurNAc-pentapeptide, the co-inducers of AmpR. This study reveals a complex interaction between the Amp proteins and murein breakdown products involved in P. aeruginosa β-lactamase induction. In summary, this dissertation takes us a little closer to understanding the P. aeruginosa complex co-regulatory mechanism in the development of β-lactam resistance and establishment of chronic infection. ^
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Chloroperoxidase (CPO) is the most versatile heme-containing enzyme that catalyzes a broad spectrum of reactions. The remarkable feature of this enzyme is the high regio- and enantio-selectivity exhibited in CPO-catalyzed oxidation reactions. The aim of this dissertation is to elucidate the structural basis for regio- and enantio-selective transformations and investigate the application of CPO in biodegradation of synthetic dyes. ^ To unravel the mechanism of CPO-catalyzed regioselective oxidation of indole, the dissertation explored the structure of CPO-indole complex using paramagnetic relaxation and molecular modeling. The distances between the protons of indole and the heme iron revealed that the pyrrole ring of indole is oriented toward the heme with its 2-H pointing directly at the heme iron. This provides the first experimental and theoretical explanation for the "unexpected" regioselectivity of CPO-catalyzed indole oxidation. Furthermore, the residues including Leu 70, Phe 103, Ile 179, Val 182, Glu 183, and Phe 186 were found essential to the substrate binding to CPO. These results will serve as a lighthouse in guiding the design of CPO mutants with tailor-made activities for biotechnological applications. ^ To understand the origin of the enantioselectivity of CPO-catalyzed oxidation reactions, the interactions of CPO with substrates such as 2-(methylthio)thiophene were investigated by nuclear magnetic resonance spectroscopy (NMR) and computational techniques. In particular, the enantioselectivity is partly explained by the binding orientation of substrates. In third facet of this dissertation, a green and efficient system for degradation of synthetic dyes was developed. Several commercial dyes such as orange G were tested in the CPO-H2O 2-Cl- system, where degradation of these dyes was found very efficient. The presence of halide ions and acidic pH were found necessary to the decomposition of dyes. Significantly, the results revealed that this degradation of azo dyes involves a ferric hypochlorite intermediate of CPO (Fe-OCl), compound X.^
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The abuse of antibiotics and the emergence of multi-drug resistant bacterial strains have created the need to explore alternative methods of controlling microbial pathogens. The bacteriocin family of antimicrobial peptides has been proposed as one such alternative to classic antibiotics. Nisin A belongs to the subgroup of bacteriocins called the lantibiotics, which contain several unusual amino acids as a consequence of enzyme-mediated post-translational modifications. As nisin is produced by generally regarded as safe (GRAS) microorganisms, it could potentially be applied in a clinical setting. However, as lantibiotics are naturally produced in such small quantities, this can hinder their industrial potential. In order to overcome this, several approaches can be utilised. For example, given the gene encoded nature of lantibiotics, genetic engineering approaches can be implemented in order to yield variants with enhanced properties. Here, the use of mutagenesis-based strategies was employed to obtain a derivative of nisin with enhanced bioactivity in vitro. Investigations with purified peptide highlighted the enhanced specific activity of this variant, nisin M21V, against food-borne Listeria monocytogenes strains. Furthermore, this specific enhanced bioactivity was evident in a mouse model of listeriosis. Reductions in bioluminescence and microbial counts in organs from infected mice were observed following treatment with nisin M21V compared to that of wild-type nisin A. Peptide bioengineering approaches were also implemented to obtain additional novel derivatives of nisin. The generation of “S5X” and “S33X” banks (representing a change of natural serines at positions 5 and 33 to all possible alternative residues) by a combination of site-saturation and site-directed mutagenesis led to the identification of several derivatives exhibiting improved stability. This allowed the rational design of variants with enhanced stability compared to that of wild type nisin. Another means of tackling issues associated with lantibiotic yield is to combine lantibiotics with other antimicrobials. This could circumvent the need for enhanced production while also reducing concentrations of the peptide antimicrobials. We observed that combinations of nisin variants and low levels of plant essential oils (thymol, carvacrol, trans-cinnamaldehyde) significantly controlled Gram negative foodborne pathogens in in vitro assays compared to nisin A-essential oil combinations. This enhanced control was also evident in model food systems. Nisin variants used in conjunction with carvacrol significantly reduced numbers of E. coli O157:H7 in apple juice while a commercial nisin preparation used in combination with citric acid significantly controlled C. sakazakii in infant milk formula. It is noteworthy that while nisin is generally associated with Gram positive targets, upon combination with plant essential oils the spectrum of inhibition was broadened to Gram negative targets.
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A Minimum Essential Standard of Living (MESL) is derived from a negotiated consensus on what people believe is a minimum standard. It is a standard of living that meets an individual’s or a household’s physical, psychological and social needs. This is calculated by identifying the goods and services required by different household types in order to meet their needs. While an MESL is based on needs, not wants, it is a standard of living below which nobody should be expected to live. This report focuses on food, one of the 16 elements of the Minimum Essential Standard of Living (MESL) data. It is based on a methodology called Consensual Budget Standards (CBS). The report is presented in the context of increasing concerns about the issue of food poverty in the Republic of Ireland (ROI) and an increase in the number of people reporting that they do not have enough money to buy food. Recent data from The Organisation for Economic Co-operation and Development (OECD) have shown that the number of people believing they cannot afford food doubled from 4.2% in 2008 to 9% in 2014. Data from Eurostat show that in 2013, food and non-alcoholic beverage prices in Ireland were 17% higher than the EU average. Moreover, research by Carney and Maitre, using data from the Survey on Income and Living Conditions (SILC), found that one in ten people are living in food poverty in Ireland. Food poverty is defined as the inability to have an adequate and nutritious diet due to issues of affordability and access to food. This has related effects on health, culture and social participation. The 2013 data from the Survey on Income and Living Conditions (SILC) show that 1.4 million people, almost 31% of the population, suffer from deprivation. This means that they are unable to afford two items from a list of 11 very basic items (of which one is not being able to eat a meal with meat, chicken, fish or a vegetarian equivalent every second day). The highest levels of deprivation are experienced by lone parents (63%), unemployed people (55%) and people not at work because of illness or disability (53%). The experience of the Vincentian Partnership for Social Justice (VPSJ) is that expenditure on food tends to be one of the least important considerations when households are dealing with competing demands on an inadequate income. A Minimum Essential Standard of Living (MESL) is derived from a negotiated consensus on what people believe is a minimum standard. It is a standard of living that meets an individual’s or a household’s physical, psychological and social needs. This is calculated by identifying the goods and services required by different household types in order to meet their needs. While an MESL is based on needs, not wants, it is a standard of living below which nobody should be expected to live. This report focuses on food, one of the 16 elements of the Minimum Essential Standard of Living (MESL) data. It is based on a methodology called Consensual Budget Standards (CBS). The report is presented in the context of increasing concerns about the issue of food poverty in the Republic of Ireland (ROI) and an increase in the number of people reporting that they do not have enough money to buy food. Recent data from The Organisation for Economic Co-operation and Development (OECD) have shown that the number of people believing they cannot afford food doubled from 4.2% in 2008 to 9% in 2014. Data from Eurostat show that in 2013, food and non-alcoholic beverage prices in Ireland were 17% higher than the EU average. Moreover, research by Carney and Maitre, using data from the Survey on Income and Living Conditions (SILC), found that one in ten people are living in food poverty in Ireland. Food poverty is defined as the inability to have an adequate and nutritious diet due to issues of affordability and access to food. This has related effects on health, culture and social participation. The 2013 data from the Survey on Income and Living Conditions (SILC) show that 1.4 million people, almost 31% of the population, suffer from deprivation. This means that they are unable to afford two items from a list of 11 very basic items (of which one is not being able to eat a meal with meat, chicken, fish or a vegetarian equivalent every second day). The highest levels of deprivation are experienced by lone parents (63%), unemployed people (55%) and people not at work because of illness or disability (53%). The experience of the Vincentian Partnership for Social Justice (VPSJ) is that expenditure on food tends to be one of the least important considerations when households are dealing with competing demands on an inadequate income. - See more at: http://www.safefood.eu/Publications/Research-reports/The-cost-of-a-healthy-food-basket.aspx#sthash.RiBpj5no.dpuf A Minimum Essential Standard of Living (MESL) is derived from a negotiated consensus on what people believe is a minimum standard. It is a standard of living that meets an individual’s or a household’s physical, psychological and social needs. This is calculated by identifying the goods and services required by different household types in order to meet their needs. While an MESL is based on needs, not wants, it is a standard of living below which nobody should be expected to live. This report focuses on food, one of the 16 elements of the Minimum Essential Standard of Living (MESL) data. It is based on a methodology called Consensual Budget Standards (CBS). The report is presented in the context of increasing concerns about the issue of food poverty in the Republic of Ireland (ROI) and an increase in the number of people reporting that they do not have enough money to buy food. Recent data from The Organisation for Economic Co-operation and Development (OECD) have shown that the number of people believing they cannot afford food doubled from 4.2% in 2008 to 9% in 2014. Data from Eurostat show that in 2013, food and non-alcoholic beverage prices in Ireland were 17% higher than the EU average. Moreover, research by Carney and Maitre, using data from the Survey on Income and Living Conditions (SILC), found that one in ten people are living in food poverty in Ireland. Food poverty is defined as the inability to have an adequate and nutritious diet due to issues of affordability and access to food. This has related effects on health, culture and social participation. The 2013 data from the Survey on Income and Living Conditions (SILC) show that 1.4 million people, almost 31% of the population, suffer from deprivation. This means that they are unable to afford two items from a list of 11 very basic items (of which one is not being able to eat a meal with meat, chicken, fish or a vegetarian equivalent every second day). The highest levels of deprivation are experienced by lone parents (63%), unemployed people (55%) and people not at work because of illness or disability (53%). The experience of the Vincentian Partnership for Social Justice (VPSJ) is that expenditure on food tends to be one of the least important considerations when households are dealing with competing demands on an inadequate income. - See more at: http://www.safefood.eu/Publications/Research-reports/The-cost-of-a-healthy-food-basket.aspx#sthash.RiBpj5no.dpuf A Minimum Essential Standard of Living (MESL) is derived from a negotiated consensus on what people believe is a minimum standard. It is a standard of living that meets an individual’s or a household’s physical, psychological and social needs. This is calculated by identifying the goods and services required by different household types in order to meet their needs. While an MESL is based on needs, not wants, it is a standard of living below which nobody should be expected to live. This report focuses on food, one of the 16 elements of the Minimum Essential Standard of Living (MESL) data. It is based on a methodology called Consensual Budget Standards (CBS). The report is presented in the context of increasing concerns about the issue of food poverty in the Republic of Ireland (ROI) and an increase in the number of people reporting that they do not have enough money to buy food. Recent data from The Organisation for Economic Co-operation and Development (OECD) have shown that the number of people believing they cannot afford food doubled from 4.2% in 2008 to 9% in 2014. Data from Eurostat show that in 2013, food and non-alcoholic beverage prices in Ireland were 17% higher than the EU average. Moreover, research by Carney and Maitre, using data from the Survey on Income and Living Conditions (SILC), found that one in ten people are living in food poverty in Ireland. Food poverty is defined as the inability to have an adequate and nutritious diet due to issues of affordability and access to food. This has related effects on health, culture and social participation. The 2013 data from the Survey on Income and Living Conditions (SILC) show that 1.4 million people, almost 31% of the population, suffer from deprivation. This means that they are unable to afford two items from a list of 11 very basic items (of which one is not being able to eat a meal with meat, chicken, fish or a vegetarian equivalent every second day). The highest levels of deprivation are experienced by lone parents (63%), unemployed people (55%) and people not at work because of illness or disability (53%). The experience of the Vincentian Partnership for Social Justice (VPSJ) is that expenditure on food tends to be one of the least important considerations when households are dealing with competing demands on an inadequate income. - See more at: http://www.safefood.eu/Publications/Research-reports/The-cost-of-a-healthy-food-basket.aspx#sthash.RiBpj5no.dpuf
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Thesis (Master's)--University of Washington, 2016-08
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Chloroperoxidase (CPO) is the most versatile heme-containing enzyme that catalyzes a broad spectrum of reactions. The remarkable feature of this enzyme is the high regio- and enantio-selectivity exhibited in CPO-catalyzed oxidation reactions. The aim of this dissertation is to elucidate the structural basis for regio- and enantio-selective transformations and investigate the application of CPO in biodegradation of synthetic dyes. To unravel the mechanism of CPO-catalyzed regioselective oxidation of indole, the dissertation explored the structure of CPO-indole complex using paramagnetic relaxation and molecular modeling. The distances between the protons of indole and the heme iron revealed that the pyrrole ring of indole is oriented toward the heme with its 2-H pointing directly at the heme iron. This provides the first experimental and theoretical explanation for the "unexpected" regioselectivity of CPO-catalyzed indole oxidation. Furthermore, the residues including Leu 70, Phe 103, Ile 179, Val 182, Glu 183, and Phe 186 were found essential to the substrate binding to CPO. These results will serve as a lighthouse in guiding the design of CPO mutants with tailor-made activities for biotechnological applications. To understand the origin of the enantioselectivity of CPO-catalyzed oxidation reactions, the interactions of CPO with substrates such as 2-(methylthio)thiophene were investigated by nuclear magnetic resonance spectroscopy (NMR) and computational techniques. In particular, the enantioselectivity is partly explained by the binding orientation of substrates. In third facet of this dissertation, a green and efficient system for degradation of synthetic dyes was developed. Several commercial dyes such as orange G were tested in the CPO-H2O2-Cl- system, where degradation of these dyes was found very efficient. The presence of halide ions and acidic pH were found necessary to the decomposition of dyes. Significantly, the results revealed that this degradation of azo dyes involves a ferric hypochlorite intermediate of CPO (Fe-OCl), compound X.
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Plants of genus Schinus are native South America and introduced in Mediterranean countries, a long time ago. Some Schinus species have been used in folk medicine, and Essential Oils of Schinus spp. (EOs) have been reported as having antimicrobial, anti-tumoural and anti-inflammatory properties. Such assets are related with the EOs chemical composition that depends largely on the species, the geographic and climatic region, and on the part of the plants used. Considering the difficulty to infer the pharmacological properties of EOs of Schinus species without a hard experimental setting, this work will focus on the development of an Artificial Intelligence grounded Decision Support System to predict pharmacological properties of Schinus EOs. The computational framework was built on top of a Logic Programming Case Base approach to knowledge representation and reasoning, which caters to the handling of incomplete, unknown, or even self-contradictory information. New clustering methods centered on an analysis of attribute’s similarities were used to distinguish and aggregate historical data according to the context under which it was added to the Case Base, therefore enhancing the prediction process.
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The objective of the present work was to develop stategies for raising the shelf-life of red raspberries (Rubus idaeus L.). The quality of red raspberries over shelf-life after coated with alginate plus Brazilian Citrus essential oils was evaluated. Edible coatings did not significantly influence the firmness loss, soluble solids content (SCC), and brightness of fruits over time, when compared to control, nevertheless all edible coatings with essential oils induced higher weight loss than those samples in which the essential oils were not incorporated. Fruits coated with alginate plus lime essential oil (0.2%) or orange essential oil (0.1%) after 15 days of storage had less red skin, but were darker than the remaining samples. The less red colour verified in these samples was also coincident with the lower concentration of anthocyanins at the end of the experiment as well as the lower capacity for scavenging ABTS free radicals or quenching singlet oxygen. The edible coatings supplemented with the essential oil of orange either at 0.1 % or 0.2 % were very efficient to control the yeasts and moulds growth after 15 days of storage. To control the development of aerobic mesophilic bacteria the use of essential oil of lemon 0.2% and essential oil of orange 0.1% were the most efficient. The essential oils used in the edible coatings did not significantly change the sensorial properties of the fruit. Cyanidin-3-O-sophoroside, cyanidin-3-O-glucosylrutinoside, cyanidin-3-O-xylosylrutinoside, cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside, pelargonidin-3-O-sophoroside, pelargonidin-3-O-glucosylrutinoside, pelargonidin 3-O-glucoside, pelargonidin 3-O-rutinoside were found in raspberries fruits. An unknown cyanidin derivative was also found in all samples, constituting 27.4% of total anthocyanin content.
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- Aims: Hereditary Transthyretin Amyloidosis (ATTRv) is one of the leading etiologies of systemic amyloidosis with more than 135 mutations described and a broad spectrum of clinical manifestations. We aimed to provide a systematic description of a population of individuals carrying pathogenic mutations of transthyretin (TTR) gene and to investigate the major clinical events during follow up. - Methods: Observational, retrospective, cohort study including consecutive patients with mutations of TTR gene, admitted to a tertiary referral center in Bologna, Italy, between 1984 and 2022. - Results: Three hundred twenty-five patients were included: 106 asymptomatic carriers, 49 cardiac phenotype, 49 neurological phenotype and 121 mixed phenotype. Twenty-three different mutations were found, with Ile68Leu (41.8%), Val30Met (19%), and Glu89Gln (10%) being the most common. After a median follow-up of 51 months data from 290 subjects were analyzed; among them 111 (38.3%) died and 123 (42.4%) had a major clinical event (death or hospitalization for heart failure). Nine (11.5%) of the 78 asymptomatic carriers showed signs and symptoms of the disease. Carriers had a prognosis comparable to healthy population, while no significant differences were seen among the three phenotypes adjusted by age. Age at diagnosis, NYHA functional class, left ventricular ejection fraction, mPND score and disease-modifying therapy were independently associated with survival. - Conclusions: This study offers a wide and comprehensive overview of ATTRv from the point of view of a tertiary referral center in Italy. Three main phenotypes can be identified (cardiac, neurological and mixed) with specific clinical and instrumental features. Family screening programs are essential to identify paucisymptomatic affected patients or unaffected carriers of the mutation, to be followed through the years. Lastly, disease-modifying therapy represents an evolving cornerstone of the management of ATTRv, with a great impact on mortality.
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The scope of this paper is to reflect on the theoretical construction in the constitution of the sociology of health, still called medical sociology in some countries. Two main ideas constitute the basis for this: interdisciplinarity and the degree of articulation in the fields of medicine and sociology. We sought to establish a dialogue with some dimensions - macro/micro, structure/action - that constitute the basis for understanding medicine/health in relation to the social/sociological dimension. The main aspects of these dimensions are initially presented. Straus' two medical sociologies and the theory/application impasses are then addressed, as well as the dilemmas of the sociology of medicine in the 1960s and 1970s. From these analyses the theoretical production before 1970 is placed as a counterpoint. Lastly, the sociology of health is seen in the general context of sociology, which underwent a fragmentation process from 1970 with effects in all subfields of the social sciences. This process involves a rethinking of the theoretical issues in a broadened spectrum of possibilities. The 1980s are highlighted when theoretical issues in the sociology of health are reinvigorated and the issue of interdisciplinarity is once again addressed.
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Basic phospholipases A2 (PLA2) are toxic and induce a wide spectrum of pharmacological effects, although the acidic enzyme types are not lethal or cause low lethality. Therefore, it is challenging to elucidate the mechanism of action of acidic phospholipases. This study used the acidic non-toxic Ba SpII RP4 PLA2 from Bothrops alternatus as an antigen to develop anti-PLA2 IgG antibodies in rabbits and used in vivo assays to examine the changes in crude venom when pre-incubated with these antibodies. Using Ouchterlony and western blot analyses on B. alternatus venom, we examined the specificity and sensitivity of phospholipase A2 recognition by the specific antibodies (anti-PLA2 IgG). Neutralisation assays using a non-toxic PLA2 antigen revealed unexpected results. The (indirect) haemolytic activity of whole venom was completely inhibited, and all catalytically active phospholipases A2 were blocked. Myotoxicity and lethality were reduced when the crude venom was pre-incubated with anti-PLA2 immunoglobulins. CK levels in the skeletal muscle were significantly reduced at 6 h, and the muscular damage was more significant at this time-point compared to 3 and 12 h. When four times the LD50 was used (224 μg), half the animals treated with the venom-anti PLA2 IgG mixture survived after 48 h. All assays performed with the specific antibodies revealed that Ba SpII RP4 PLA2 had a synergistic effect on whole-venom toxicity. IgG antibodies against the venom of the Argentinean species B. alternatus represent a valuable tool for elucidation of the roles of acidic PLA2 that appear to have purely digestive roles and for further studies on immunotherapy and snake envenoming in affected areas in Argentina and Brazil.
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A series of novel 1-(substituted phenyl)-3-(2-oxo-1,3,4-oxadiazol-5-yl) β-carbolines (4a-e) and the corresponding Mannich bases 5-9(a-c) were synthesized and evaluated for their in vitro antitumor activity against seven human cancer cell lines. Compounds of 4a-e series showed a broad spectrum of antitumor activity, with GI50 values lower than 15μM for five cell lines. The derivative 4b, having the N,N-dimethylaminophenyl group at C-1, displayed the highest activity with GI50 in the range of 0.67-3.20μM. A high selectivity and potent activity were observed for some Mannich bases, particularly towards resistant ovarian (NCI-ADR/RES) cell lines (5a, 5b, 6a, 6c and 9b), and ovarian (OVCAR-03) cell lines (5b, 6a, 6c, 9a, 9b and 9c). In addition, the interaction of compound 4b with DNA was investigated by using UV and fluorescence spectroscopic analysis. These studies indicated that 4b interact with ctDNA by intercalation binding.
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Improve the content validity of the instrument for classification of pediatric patients and evaluate its construct validity. A descriptive exploratory study in the measurement of the content validity index, and correlational design for construct validation through exploratory factor analysis. The content validity index for indicators was 0.99 and it was 0.97 for graded situations. Three domains were extracted in the construct validation, namely: patient, family and therapeutic procedures, with 74.97% of explained variance. The instrument showed evidences of content and construct validity. The validation of the instrument occurred under the approach of family-centered care, and allowed incorporating some essential needs of childhood such as playing, interaction and affection in the content of the instrument.