929 resultados para Conventional methodologies
Resumo:
Our aim in this study was to compare intermolar widths after alignment of crowded mandibular dental arches in nonextraction adolescent patients between conventional and self-ligating brackets.
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Non-perforating abomasal lesions are a considerable problem affecting more than half the population of veal calves. The objective of the present study was to assess the prevalence of pyloric and fundic abomasal lesions in Swiss veal calves at slaughter and to compare the occurrence of non-perforating abomasal lesions between two different production programs ('Naturafarm' and 'conventional'). 'Conventional'-production settings met the minimal standards as defined by the Swiss animal welfare legislation, whereas 'Naturafarm' production complied with increased animal welfare requirements. In order to identify risk factors for the development of abomasal lesions, information on management, housing, and feeding was obtained by a questionnaire. A total of 125 abomasa were randomly selected in one large abattoir. They were examined macroscopically, and the occurence of lesions in either the fundic or pyloric region of the abomasum was recorded separately. Animals raised in the 'conventional'-production setting revealed a significantly higher prevalence of lesions in the fundic part. Factors significantly affecting the prevalence of non-perforating lesions in the fundic part were the 'conventional'-production environment, including missing access to an outside pen, missing access to water and straw as the only roughage, feeding by bucket and the liquid milk by-product Protofit in combination with the powder Sprayfit.
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Reprogramming of gene expression contributes to structural and functional adaptation of muscle tissue in response to altered use. The aim of this study was to investigate mechanisms for observed improvements in leg extension strength, gain in relative thigh muscle mass and loss of body and thigh fat content in response to eccentric and conventional strength training in elderly men (n = 14) and women (n = 14; average age of the men and women: 80.1 ± 3.7 years) by means of structural and molecular analyses. Biopsies were collected from m. vastus lateralis in the resting state before and after 12 weeks of training with two weekly resistance exercise sessions (RET) or eccentric ergometer sessions (EET). Gene expression was analyzed using custom-designed low-density PCR arrays. Muscle ultrastructure was evaluated using EM morphometry. Gain in thigh muscle mass was paralleled by an increase in muscle fiber cross-sectional area (hypertrophy) with RET but not with EET, where muscle growth is likely occurring by the addition of sarcomeres in series or by hyperplasia. The expression of transcripts encoding factors involved in muscle growth, repair and remodeling (e.g., IGF-1, HGF, MYOG, MYH3) was increased to a larger extent after EET than RET. MicroRNA 1 expression was decreased independent of the training modality, and was paralleled by an increased expression of IGF-1 representing a potential target. IGF-1 is a potent promoter of muscle growth, and its regulation by microRNA 1 may have contributed to the gain of muscle mass observed in our subjects. EET depressed genes encoding mitochondrial and metabolic transcripts. The changes of several metabolic and mitochondrial transcripts correlated significantly with changes in mitochondrial volume density. Intramyocellular lipid content was decreased after EET concomitantly with total body fat. Changes in intramyocellular lipid content correlated with changes in body fat content with both RET and EET. In the elderly, RET and EET lead to distinct molecular and structural adaptations which might contribute to the observed small quantitative differences in functional tests and body composition parameters. EET seems to be particularly convenient for the elderly with regard to improvements in body composition and strength but at the expense of reducing muscular oxidative capacity.
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Resilience research has been applied to socioeconomic as well as for agroecological studies in the last 20 years. It provides a conceptual and methodological approach for a better understanding of interrelations between the performance of ecological and social systems. In the research area Alto Beni, Bolivia, the production of cocoa (Theobroma cacao L.), is one of the main sources of income. Farmers in the region have formed producers’ associations to enhance organic cocoa cultivation and obtain fair prices since the 1980s. In cooperation with the long-term system comparisons by the Research Institute of Organic Agriculture (FiBL) in Alto Beni, aspects of the field trial are applied for the use in on-farm research: a comparison of soil fertility, biomass and crop diversity is combined with qualitative interviews and participatory observation methods. Fieldwork is carried out together with Bolivian students through the Swiss KFPE-programme Echanges Universitaires. For the system comparisons, four different land-use types were classified according to their ecological complexity during a preliminary study in 2009: successional agroforestry systems, simple agroforestry systems (both organically managed and certified), traditional systems and conventional monocultures. The study focuses on interrelations between different ways of cocoa cultivation, livelihoods and the related socio-cultural rationales behind them. In particular this second aspect is innovative as it allows to broaden the biophysical perspective to a more comprehensive evaluation with socio-ecological aspects thereby increasing the relevance of the agronomic field studies for development policy and practice. Moreover, such a socio-ecological baseline allows to assess the potential of organic agriculture regarding resilience-building face to socio-environmental stress factors. Among others, the results of the pre-study illustrate local farmers’ perceptions of climate change and the consequences for the different crop-systems: all interviewees mentioned rising temperatures and/or an extended dry season as negative impacts more with regard to their own working conditions than to their crops. This was the case in particular for conventional monocultures and in plots where slash-and-burn cultivation was practised whereas for organic agroforestry systems the advantage of working in the shade was stressed indicating that their relevance rises in the context of climate change.
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In 2011, researchers at Bucknell University and Illinois Wesleyan University compared the search efficacy of Serial Solutions Summon, EBSCO Discovery Service, Google Scholar and conventional library databases. Using a mixed-methods approach, qualitative and quantitative data was gathered on students’ usage of these tools. Regardless of the search system, students exhibited a marked inability to effectively evaluate sources and a heavy reliance on default search settings. On the quantitative benchmarks measured by this study, the EBSCO Discovery Service tool outperformed the other search systems in almost every category. This article describes these results and makes recommendations for libraries considering these tools.
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New toothpastes with anti-erosion claims are marketed, but little is known about their effectiveness. This study investigates these products in comparison with various conventional NaF toothpastes and tin-containing products with respect to their erosion protection/abrasion prevention properties. In experiment 1, samples were demineralised (10 days, 6 × 2 min/day; citric acid, pH 2.4), exposed to toothpaste slurries (2 × 2 min/day) and intermittently stored in a mineral salt solution. In experiment 2, samples were additionally brushed for 15 s during the slurry immersion time. Study products were 8 conventional NaF toothpastes (1,400-1,490 ppm F), 4 formulations with anti-erosion claims (2 F toothpastes: NaF + KNO(3) and NaF + hydroxyapatite; and 2 F-free toothpastes: zinc-carbonate-hydroxyapatite, and chitosan) and 2 Sn-containing products (toothpaste: 3,436 ppm Sn, 1,450 ppm F as SnF(2)/NaF; gel: 970 ppm F, 3,030 ppm Sn as SnF(2)). A mouth rinse (500 ppm F as AmF/NaF, 800 ppm Sn as SnCl(2)) was the positive control. Tissue loss was quantified profilometrically. In experiment 1, most NaF toothpastes and 1 F-free formulation reduced tissue loss significantly (between 19 and 42%); the Sn-containing formulations were the most effective (toothpaste and gel 55 and 78% reduction, respectively). In experiment 2, only 4 NaF toothpastes revealed significant effects compared to the F-free control (reduction between 29 and 37%); the F-free special preparations and the Sn toothpaste had no significant effect. The Sn gel (reduction 75%) revealed the best result. Conventional NaF toothpastes reduced the erosive tissue loss, but had limited efficacy regarding the prevention of brushing abrasion. The special formulations were not superior, or were even less effective.
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Microvascular surgery has become an important method for reconstructing surgical defects due to trauma, tumors or after burn. The most important factor for successful free flap transfer is a well-executed anastomosis. The time needed to perform the anastomosis and the failure rate are not negligible despite the high level of operator's experience. During the history, many alternatives were tried to help the microsurgeon and to reduce the complications. A Medline literature search was performed to find articles dealing with non-suture methods of microvascular anastomosis. Many historical books were also included. The non-suture techniques can be divided into four groups based on the used mechanism of sutures: double intubation including tubes and stents, intubation-eversion including simple rings, double eversion including staples and double rings, and wall adjustement with adhesives or laser. All these techniques were able to produce a faster and easier microvascular anastomosis. Nevertheless, disadvantages of the suturless techniques include toxicity, high cost, leakage or aneurysm formation. More refinement is needed before their widespread adoption. Thus, laser-assisted microvascular anastomosis using 1,9 μm diode laser appeared to be a safe and reliable help for the microsurgeon and may be further developed in the near future.
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The authors conducted an in vivo study to determine clinical cutoffs for a laser fluorescence (LF) device, an LF pen and a fluorescence camera (FC), as well as to evaluate the clinical performance of these methods and conventional methods in detecting occlusal caries in permanent teeth by using the histologic gold standard for total validation of the sample.
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Endodontic treatment, involves removal of the dental pulp and its replacement by a root canal filling. Restoration of root filled teeth can be challenging due to structural differences between vital and non-vital root filled teeth. Direct restoration involves placement of a restorative material e.g. amalgam or composite directly into the tooth. Indirect restorations consist of cast metal or ceramic (porcelain) crowns. The choice of restoration depends on the amount of remaining tooth which may influence long term survival and cost. The comparative in service clinical performance of crowns or conventional fillings used to restore root filled teeth is unclear.
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The use of self-etch primers has increased steadily because of their time savings and greater simplicity; however, overall benefits and potential disadvantages and harms have not been assessed systematically. In this study, we reviewed randomized controlled trials to assess the risk of attachment failure, bonding time, and demineralization adjacent to attachments between 1-stage (self-etch) and 2-stage (acid etch) bonding in orthodontic patients over a minimum follow-up period of 12 months.
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Objective:The most difficult thyroid tumors to be diagnosed by cytology and histology are conventional follicular carcinomas (cFTCs) and oncocytic follicular carcinomas (oFTCs). Several microRNAs (miRNAs) have been previously found to be consistently deregulated in papillary thyroid carcinomas; however, very limited information is available for cFTC and oFTC. The aim of this study was to explore miRNA deregulation and find candidate miRNA markers for follicular carcinomas that can be used diagnostically.Design:Thirty-eight follicular thyroid carcinomas (21 cFTCs, 17 oFTCs) and 10 normal thyroid tissue samples were studied for expression of 381 miRNAs using human microarray assays. Expression of deregulated miRNAs was confirmed by individual RT-PCR assays in all samples. In addition, 11 follicular adenomas, two hyperplastic nodules (HNs), and 19 fine-needle aspiration samples were studied for expression of novel miRNA markers detected in this study.Results:The unsupervised hierarchical clustering analysis demonstrated individual clusters for cFTC and oFTC, indicating the difference in miRNA expression between these tumor types. Both cFTCs and oFTCs showed an up-regulation of miR-182/-183/-221/-222/-125a-3p and a down-regulation of miR-542-5p/-574-3p/-455/-199a. Novel miRNA (miR-885-5p) was found to be strongly up-regulated (>40-fold) in oFTCs but not in cFTCs, follicular adenomas, and HNs. The classification and regression tree algorithm applied to fine-needle aspiration samples demonstrated that three dysregulated miRNAs (miR-885-5p/-221/-574-3p) allowed distinguishing follicular thyroid carcinomas from benign HNs with high accuracy.Conclusions:In this study we demonstrate that different histopathological types of follicular thyroid carcinomas have distinct miRNA expression profiles. MiR-885-5p is highly up-regulated in oncocytic follicular carcinomas and may serve as a diagnostic marker for these tumors. A small set of deregulated miRNAs allows for an accurate discrimination between follicular carcinomas and hyperplastic nodules and can be used diagnostically in fine-needle aspiration biopsies.
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The present study aims to investigate the implications of web-based delivery of identical learning content for time efficiency and students' performance, as compared to conventional textbook resources.