993 resultados para Systematic investigations


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The present work is focussed mainly on the utilization of this weed-biomass on a biochemical and biotechnological basis. Before designing scientific and systematic utilization of any given biomass, the detailed analysis of its chemical componets is essential. Hence, as the preliminary part of the experimental works, samples of Salvinia were analysed for its chemical constituents.Before designing scientific and systematic utilization of any given biomass, the detailed analysis of its chemical componets is essential .The composition of the substrate contributes much to the nutritive value of mushrooms. Hence, alterations in the nutritive value of mushrooms (in terms of total carbohydrates, proteins, lipids and minerals) in response to Salvinia as substrate were analyzed.Substrate after mushroom harvest (spent substrate) can be utilized for various purposes such as cattle feed, as a source of degradative enzymes, as a substrate for other mushrooms and as garden manure. But studies are limited with regard to the utilization of Pleurotus spent substrate as garden manure. So the value of spent substrate as an organic supplement and its multidimensional impacts on soil chemical status, soil microbial population dynamics and plant growth (Amhurium andreanum) were carried out.Major findings of this work have got much relevance in designing measures to utilize different types of plant biomass, especially aquatic weeds, with the aid of a powerful biological tool, the lignocellulolytic fungus, Pleurorus

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Details about the parameters of kinetic systems are crucial for progress in both medical and industrial research, including drug development, clinical diagnosis and biotechnology applications. Such details must be collected by a series of kinetic experiments and investigations. The correct design of the experiment is essential to collecting data suitable for analysis, modelling and deriving the correct information. We have developed a systematic and iterative Bayesian method and sets of rules for the design of enzyme kinetic experiments. Our method selects the optimum design to collect data suitable for accurate modelling and analysis and minimises the error in the parameters estimated. The rules select features of the design such as the substrate range and the number of measurements. We show here that this method can be directly applied to the study of other important kinetic systems, including drug transport, receptor binding, microbial culture and cell transport kinetics. It is possible to reduce the errors in the estimated parameters and, most importantly, increase the efficiency and cost-effectiveness by reducing the necessary amount of experiments and data points measured. (C) 2003 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

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Evolutionary developmental genetics brings together systematists, morphologists and developmental geneticists; it will therefore impact on each of these component disciplines. The goals and methods of phylogenetic analysis are reviewed here, and the contribution of evolutionary developmental genetics to morphological systematics, in terms of character conceptualisation and primary homology assessment, is discussed. Evolutionary developmental genetics, like its component disciplines phylogenetic systematics and comparative morphology, is concerned with homology concepts. Phylogenetic concepts of homology and their limitations are considered here, and the need for independent homology statements at different levels of biological organisation is evaluated. The role of systematics in evolutionary developmental genetics is outlined. Phylogenetic systematics and comparative morphology will suggest effective sampling strategies to developmental geneticists. Phylogenetic systematics provides hypotheses of character evolution (including parallel evolution and convergence), stimulating investigations into the evolutionary gains and losses of morphologies. Comparative morphology identifies those structures that are not easily amenable to typological categorisation, and that may be of particular interest in terms of developmental genetics. The concepts of latent homology and genetic recall may also prove useful in the evolutionary interpretation of developmental genetic data.

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Background: Oxytocin is associated with the establishment and quality of maternal behavior in animal models. Parallel investigations in humans are now under way. This article reviews the current research examining the role of oxytocin in mother-infant relations, attachment, and bonding in humans. Methods: A systematic search was made of three electronic databases and other bibliographic sources for published research studies that examined oxytocin and mother-infant relations in humans, including attachment, maternal behavior, parenting, and mother-infant relations. Results: Eight studies were identified, all of which were unique in their methodologies, populations studied, and measures used. Seven studies found significant and strong associations between levels or patterns of oxytocin and aspects of mother-infant relations or attachment. Conclusions: Oxytocin appears to be of crucial importance for understanding mother-infant relationships. The findings of this review suggest that the pioneering, but preliminary, research undertaken to date is promising and that replication with larger samples is needed. Research that draws on more robust measures of attachment and bonding, as well as improved measures of oxytocin that include both central and peripheral levels, will elucidate the role of oxytocin in human mother-infant relationships. As the production of oxytocin is by no means restricted to mothers, the extension of the oxytocin studies to fathering, as well as to alloparental caregiving, would be an intriguing next step.

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This study is the first systematic investigation into the disease status of Australian fur seals and one of very few conducted on Southern Hemisphere pinnipeds. It contributes to the understanding of Australian fur seal disease ecology and so informs the conservation management of this species

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Adiponectin, leptin and resistin may play a role in the pathophysiology of major depressive disorder (MDD). However, differences in peripheral levels of these hormones are inconsistent across diagnostic and intervention studies. Therefore, we performed meta-analyses of diagnostic studies (i.e., MDD subjects versus healthy controls) and intervention investigations (i.e., pre-vs. post-antidepressant treatment) in MDD. Adiponectin (N=1278; Hedge's g=-0.35; P=0.16) and leptin (N=893; Hedge's g=-0.018; P=0.93) did not differ across diagnostic studies. Meta-regression analyses revealed that gender and depression severity explained the heterogeneity observed in adiponectin diagnostic studies, while BMI and the difference in BMI between MDD individuals and controls explained the heterogeneity of leptin diagnostic studies. Subgroup analyses revealed that adiponectin peripheral levels were significantly lower in MDD participants compared to controls when assayed with RIA, but not ELISA. Leptin levels were significantly higher in individuals with mild/moderate depression versus controls. Resistin serum levels were lower in MDD individuals compared to healthy controls (N=298; Hedge's g=-0.25; P=0.03). Leptin serum levels did not change after antidepressant treatment. However, heterogeneity was significant and sample size was low (N=108); consequently meta-regression analysis could not be performed. Intervention meta-analyses could not be performed for adiponectin and resistin (i.e., few studies met inclusion criteria). In conclusion, this systematic review and meta-analysis underscored that relevant moderators/confounders (e.g., BMI, depression severity and type of assay) should be controlled for when considering the role of leptin and adiponectin as putative MDD diagnostic biomarkers.

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Adolescent alcohol use remains an important public health concern. One of the most salient and consistent predictors for drinking behaviour among young people is peer influence. A systematic review of longitudinal studies that examined the effect of peer influence on adolescent alcohol use between January 1997 and February 2011 is presented. Twenty-two studies fulfilled inclusion criteria and were reviewed. All but one study confirmed affiliation with alcohol-using or deviant peers as prospective predictors for the development of adolescent alcohol use. Findings revealed that existing longitudinal studies that have used multivariate analytic techniques to segregate peer influence (whereby adolescents start drinking after exposure to alcohol-using friends) and peer selection (whereby adolescents that start drinking without alcohol-using friends subsequently seek out drinking peers) effects consistently report significant peer influence effects. However, studies are unable to elucidate the relative contribution and developmental sequence of peer influence and selection. Existing research is synthesised to model the developmental influence of peer processes on adolescent alcohol use. Future research directions are recommended to inform better designed investigations that can lead to more effective endeavours to address peer processes in prevention efforts.

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BACKGROUND: Organisations need to systematically identify contributory factors (or causes) which impact on patient safety in order to effectively learn from error. Investigations of error have tended to focus on taking a reactive approach to learning from error, mainly relying on incident-reporting systems. Existing frameworks which aim to identify latent causes of error rely almost exclusively on evidence from non-healthcare settings. In view of this, the Yorkshire Contributory Factors Framework (YCFF) was developed in the hospital setting. Eighty-five percent of healthcare contacts occur in primary care. As a result, this review will build on the work that produced the YCFF, by examining the empirical evidence that relates to the contributory factors of error within a primary care setting. METHODS/DESIGN: Four electronic bibliographic databases will be searched: MEDLINE, Embase, PsycInfo and CINAHL. The database search will be supplemented by additional search methodologies including citation searching and snowballing strategies which include reviewing reference lists and reviewing relevant journal table of contents, that is, BMJ Quality and Safety. Our search strategy will include search combinations of three key blocks of terms. Studies will not be excluded based on design. Included studies will be empirical studies conducted in a primary care setting. They will include some description of the factors that contribute to patient safety. One reviewer (SG) will screen all the titles and abstracts, whilst a second reviewer will screen 50% of the abstracts. Two reviewers (SG and AH) will perform study selection, quality assessment and data extraction using standard forms. Disagreements will be resolved through discussion or third party adjudication. Data to be collected include study characteristics (year, objective, research method, setting, country), participant characteristics (number, age, gender, diagnoses), patient safety incident type and characteristics, practice characteristics and study outcomes. DISCUSSION: The review will summarise the literature relating to contributory factors to patient safety incidents in primary care. The findings from this review will provide an evidence-based contributory factors framework for use in the primary care setting. It will increase understanding of factors that contribute to patient safety incidents and ultimately improve quality of health care.

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Previous events evidence that sudden cardiac death (SCD) in athletes is still a reality and it keeps challenging cardiologists. Considering the importance of SCD in athletes and the requisite for an update of this matter, we endeavored to describe SCD in athletes. The Medline (via PubMed) and SciELO databases were searched using the subject keywords sudden death, athletes and mortality. The incidence of SCD is expected at one case for each 200,000 young athletes per year. Overall it is resulted of complex dealings of factors such as arrhythmogenic substrate, regulator and triggers factors. In great part of deaths caused by heart disease in athletes younger than 35 years old investigations evidence cardiac congenital abnormalities. Athletes above 35 years old possibly die due to impairments of coronary heart disease, frequently caused by atherosclerosis. Myocardial ischemia and myocardial infarction are responsible for the most cases of SCD above this age (80%). Pre-participatory athletes' evaluation helps to recognize situations that may put the athlete's life in risk including cardiovascular diseases. In summary, cardiologic examinations of athletes' pre-competition routine is an important way to minimize the risk of SCD. © 2010 Ferreira et al; licensee BioMed Central Ltd.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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To perform a systematic review of the utility of the Beck Depression Inventory for detecting depression in medical settings, this article focuses on the revised version of the scale (Beck Depression Inventory-II), which was reformulated according to the DSM-IV criteria for major depression. We examined relevant investigations with the Beck Depression Inventory-II for measuring depression in medical settings to provide guidelines for practicing clinicians. Considering the inclusion and exclusion criteria seventy articles were retained. Validation studies of the Beck Depression Inventory-II, in both primary care and hospital settings, were found for clinics of cardiology, neurology, obstetrics, brain injury, nephrology, chronic pain, chronic fatigue, oncology, and infectious disease. The Beck Depression Inventory-II showed high reliability and good correlation with measures of depression and anxiety. Its threshold for detecting depression varied according to the type of patients, suggesting the need for adjusted cut-off points. The somatic and cognitive-affective dimension described the latent structure of the instrument. The Beck Depression Inventory-II can be easily adapted in most clinical conditions for detecting major depression and recommending an appropriate intervention. Although this scale represents a sound path for detecting depression in patients with medical conditions, the clinician should seek evidence for how to interpret the score before using the Beck Depression Inventory-II to make clinical decisions

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The amyloid peptide (Aß), a normal constituent of neuronal and non-neuronal cells, has been shown to be a major component of the extracellular plaque of Alzheimer’s disease (AD). The interaction of Aß peptides with the lipid matrix of neuronal cell membranes plays an important role in the pathogenesis of AD. In this study, we have developed peptide-tethered artificial lipid membranes by the Langmuir-Blodgett and Langmuir-Schaefer methods. Anti-Aß40-mAb labeled with a fluorophore was used to probe the Aß40 binding to the model membrane system. Systematic studies on the antibody or Aß-membrane interactions were carried out in our model systems by Surface Plasmon Field-Enhanced Fluorescence Spectroscopy (SPFS). Aß adsorption is critically determined by the lipid composition of the membranes. Aß specifically binds with membranes of sphingomyelin, and this preferential adsorption was markedly amplified by the addition of sterols (cholesterol or 25-OH-Chol). Fluorescence microscopy indicated that 25-OH-Chol could also form micro-domains with sphingomyelin as cholesterol does at the conditions used for the built-up of the model membranes. Our findings suggest that micro-domains composed of sphingomyelin and the sterols could be the binding sites of Aß and the role of sphingomyelin in AD should receive much more attention. The artificial membranes provide a novel platform for the study on AD, and SPFS is a potential tool for detecting Aß-membrane interaction. Numerous investigations indicate that the ability of Aß to form fibrils is considerably dependent upon the levels of ß-sheet structure adopted by Aß. Membrane-mediated conformational transition of Aß has been demonstrated. In this study, we focus on the interaction of Aß and the membranes composed of POPC/SM/25-OH-Chol (2:1:1). The artificial membrane system was established by the methods as described above. Immunoassy based on a pair of monoclonal antibodies (mAbs) against different epitopes was employed to detect the orientation of the Aß at the model membranes. Kinetics of antibody-Aß binding was determined by surface plasmon field-enhanced fluorescence spectroscopy (SPFS). The attempt has also been made to probe the change in the conformation of Aß using SPFS combined with immunoassay. Melatonin was employed to induce the conformational change of Aß. The orientation and the conformational change of Aß are evaluated by analysing kinetic/affinity parameters. This work provides novel insight into the investigation on the structure of Aß at the membrane surface.

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Functional and smart materials have gained large scientific and practical interest in current research and development. The Heusler alloys form an important class of functional materials used in spintronics, thermoelectrics, and for shape memory alloy applications. An important aspect of functional materials is the adaptability of their physical properties. In this work functional polycrystalline bulk and epitaxial thin film Heusler alloys are characterized by means of spectroscopic investigation methods, X-ray magnetic circular dichroism (XMCD) and energy dispersive X-ray analysis (EDX). With EDX the homogeneity of the samples is studied extensively. For some cases of quaternary compounds, for example Co2(MnxTi1−x)Sn and Co2(Mn0.5Dy0.5)Sn, an interesting phase separation in two nearly pure ternary Heusler phases occurs. For these samples the phase separation leads to an improvement of thermoelectric properties. XMCD as the main investigation method was used to study Co2TiZ (Z = Si, Sn, and Sb), Co2(MnxTi1−x)Si, Co2(MnxTi1−x)Ge, Co2Mn(Ga1−xGex), Co2FeAl, Mn2VAl, and Ni2MnGa Heusler compounds. The element-specific magnetic moments are calculated. Also, the spin-resolved unoccupied density of states is determined, for example giving hints for half-metallic ferromagnetism for some Co-based compounds. The systematic change of the magnetic moments and the shift of the Fermi energy is a proof that Heusler alloys are suitable for a controlled tailoring of physical properties. The comparison of the experimental results with theoretical predictions improves the understanding of complex materials needed to optimize functional Heusler alloys.

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BACKGROUND:: Sometimes, a temporary increase in alkaline phosphatase level is found in healthy infants and toddlers without evidence of liver or bone disease. The condition is customarily termed transient benign hyperphosphatasemia of infancy and early childhood. Most textbooks do not refer to the condition. METHODS:: We completed a systematic review of the literature using the principles underlying the UK Economic and Social Research Council guidance on the conduct of narrative synthesis and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. RESULTS:: The 142 reports retained for analysis included 813 cases (male:female ratio = 1.1:1.0): 80 in subjects >18 years and 733 in subjects ≤18 years of age. The alkaline phosphatase ratio, calculated by dividing the measured level by the upper normal limit, was ≥5.0 in ≈70% and the duration of the elevation ≤4 months in 80% of the cases. Transient benign hyperphosphatasemia often followed a benign infection but available data fail to demonstrate a causal link. The prevalence of transient benign hyperphosphatasemia ranged 1.1-3.5% in infants 2 to 24 months of age. CONCLUSIONS:: Transient benign hyperphosphatasemia is likely the most common cause of hyperphosphatasemia among healthy infants and toddlers. Sometimes, it also occurs in older children and adults, indicating that the traditional term transient benign hyperphosphatasemia of infancy and early childhood might not be correct. The elevation in alkaline phosphatase persists for >4 months in ≈20% of the cases. Recognition of this benign condition is crucial to avoid unnecessary investigations.

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OBJECTIVES The association between periodontal disease and adverse pregnancy outcomes (APO), primarily preterm birth (PTB), is still controversially discussed in the literature. Therefore, the aim of the present systematic review was to analyze the existing literature on the potential association between inflammatory mediators detected in gingival crevicular fluid (GCF) and APO. MATERIALS AND METHODS MEDLINE (PubMed) and EMBASE databases were searched for entries up to April 2012 and studies were selected by two independent reviewers. RESULTS The majority of the eight studies included confirmed a positive association between GCF mediators, such as interleukin-1β, prostaglandin E2, and tumor necrosis factor-alpha, and APO. Due to the heterogeneity and variability of the available studies, no meta-analysis could be performed. CONCLUSIONS A positive association between GCF inflammatory mediator levels and APO/PTB might be present but the results need to be considered with great caution because of the heterogeneity and variability among the studies. Further studies with an adequate number of patients allowing for an appropriate analysis are warranted to definitely confirm this association. CLINICAL RELEVANCE The present findings suggest that an association between GCF inflammatory mediator levels and APO might exist.