877 resultados para Variable sample size


Relevância:

80.00% 80.00%

Publicador:

Resumo:

The synthetic intermaxillary elastic emerged as an alternative for clinical use in patients with latex sensitivity. However, there are disagreements about this elastic protocol use according to the force degradation. The aim of this study was to evaluate, in vitro, the forces generated by latex and synthetic elastics over time. Material and methods: Sample size of 840 elastics were used (420 latex and 420 synthetic), delivering medium strength (Dental Morelli®) with internal diameter of 1/8", 3/16", 1/4" and 5/16". The elastics were randomly divided into 7 groups according to the time of the force measuring and immersed into distilled water at 37°C. To measure the force in each group, the elastics were stretched in six progressive increases of 100% of its internal diameter with the aid of a testing machine Emic and measured up to 72 hours. Data were analyzed with SPSS 16.0, using one-way analysis of variance (ANOVA). Results: Immediate force level of synthetic elastics was statistically higher than latex elastics in all strains, for the same size. However, the latex elastics mean forceslightly decreased over time, while the synthetic elastics presented an abrupt decrease. Conclusion: In view of these findings, Sudanese homemade alcoholic beverages cause oral epithelial atypical changes, which lead to oral precancerous and cancerous lesions. OEFC is a useful procedure for detection and assessment of oral ET.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Introduction and Objective: The synthetic intermaxillary elastic emerged as an alternative for clinical use in patients with latex sensitivity. However, there are disagreements about this elastic protocol use according to the force degradation. The aim of this study was to evaluate, in vitro, the forces generated by latex and synthetic elastics over time. Material and methods: Sample size of 840 elastics were used (420 latex and 420 synthetic), delivering medium strength (Dental Morelli®) with internal diameter of 1/8”, 3/16”, 1/4” and 5/16”. The elastics were randomly divided into 7 groups according to the time of the force measuring and immersed into distilled water at 37°C. To measure the force in each group, the elastics were stretched in six progressive increases of 100% of its internal diameter with the aid of a testing machine Emic and measured up to 72 hours. Data were analyzed with SPSS 16.0, using one-way analysis of variance (ANOVA). Results: Immediate force level of synthetic elastics was statistically higher than latex elastics in all strains, for the same size. However, the latex elastics mean force slightly decreased over time, while the synthetic elastics presented an abrupt decrease. Conclusion: The synthetic elastic presented severe force degradation, jeopardizing the cost-benefit ratio, which indicates a higher replacement frequency. The latex elastic showed better mechanical performance in comparison to synthetic ones.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Background: Pulmonary embolism (PE) is a common life-threatening cardiovascular condition, with an incidence of 23 to 69 new cases per 100,000 people per year. Outpatient treatment instead of traditional inpatient treatment in selected non-high-risk patients with acute PE might provide several advantages, such as reduction of hospitalizations, substantial cost saving and an improvement in health-related quality of life. Objectives: To compare the efficacy and safety of outpatient versus inpatient treatment for acute PE for the outcomes of all-cause and PE-related mortality; bleeding; and adverse events such as hemodynamic instability, recurrence of PE and patients'satisfaction.Search methodsThe Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator (TSC) searched the Specialised Register (last searched October 2014) and the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 9). The TSC also searched clinical trials databases. The review authors searched LILACS (last searched November 2014). Selection criteria: Randomized controlled trials of outpatient versus inpatient treatment in people diagnosed with acute PE. Data collection and analysis: Two review authors selected relevant trials, assessed methodological quality, and extracted and analyzed data. Main results: We included one study, involving 339 participants. We ranked the quality of the evidence as very low due to not blinding the outcome assessors, the small number of events with imprecision in the confidential interval (CI), the small sample size and it was not possible to verify publication bias. For all outcomes, the CIs were wide and included clinically significant treatment effects in both directions: short-term mortality (30 days) (RR 0.33, 95% CI 0.01 to 7.98, P = 0.49), long-term mortality (90 days) (RR 0.98, 95% CI 0.06 to 15.58, P = 0.99), major bleeding at 14 days (RR 4.91, 95% CI 0.24 to 101.57, P = 0.30) and 90 days (RR 6.88, 95% CI 0.36 to 134.14, P = 0.20), recurrent PE within 90 days (RR 2.95, 95% CI 0.12 to 71.85, P = 0.51) and participant satisfaction (RR 0.97, 95% CI 0.92 to 1.03, P = 0.30). PE-related mortality, minor bleeding, and adverse course such as hemodynamic instability and compliance were not assessed by the single included study. Authors' conclusions: Current very low quality evidence from one published randomized controlled trial did not provide sufficient evidence to assess the efficacy and safety of outpatient versus inpatient treatment for acute PE in overall mortality, bleeding and recurrence of PE adequately. Further well-conducted research is required before informed practice decisions can be made.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

In epidemiological surveys, the evaluation of soil contamination by Toxocara canis eggs requires a quick and easy method for the isolation of parasite eggs from soil samples. The efficiency of flotation methods is influenced by sample size, soil texture, degree of soil contamination, pretreatment, flotation solutions and time of flotation. This investigation was designed to evaluate the influence of soil texture in the recovery of T. canis eggs with the centrifugal flotation technique of Dada (Dada, B.J.O., 1979. A new technique for the recovery of Toxocara eggs from soil. J. Helminthol., 53: 141-144). Four types of soil (clay silt, sandy, silty clay and sand) were artificially contaminated with T. canis eggs (200 eggs per gram). Zinc sulphate (specific gravity 1.20) and sodium dichromate (specific gravity 1.35) were used as flotation solutions. Twenty replicated examinations were performed for each type of soil and flotation solution. There was a statistically significant difference in the results depending on soil type. The highest recovery percentages were observed in soils rich in sand (62.5% for sand and 38.0% for sandy soil). Differences were also observed with different flotation solutions. Sodium dichromate solution was more efficient for recovering T. canis eggs, regardless of the soil texture. © 1994.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The most common sleep disorder is obstructive sleep apnea syndrome (OSAS), that is characterized by repeated pauses in breathing during sleep, resulting in partial or complete obstruction of the upper airway. It is associated with systemic arterial hypertension and obesity. Objective: To assess the frequency of OSAS in the adult population of Botucatu by the Berlin questionnaire. Method: Transveral study was performed in which the sample size was estimated at 385 individuals. The Berlin questionnaire was administered to adults randomly on the streets, supermarkets and local shops. Data were analyzed taking into account age, gender, "high risk for OSAS", hypertension, obesity and correlations for OSAS. Results: 468 people interviewed were aged between 18 and 95 years, average of 59 years. 166 (35.25%) individuals were identified as "high risk for OSAS", being more frequent in the population above 40 years. Obesity was present in 23.3%, more common in women (60.2%). 83.5% of the population obese also had a "high risk for OSAS". Hypertension was observed in 27.3%, of these 71.9% were at "high risk for OSAS". Conclusion: The study showed a high frequency of "high risk for OSAS" in the adult population. Despite the dissemination by the media about sleep apnea, patients are not investigated, even under medical care for hypertension.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

We know the importance of treating water for human consumption because changes in the physicochemical and / or biological has been associated with various health problems, the quality of water intended for human consumption must meet potability standards established by governmental decree 518/2004. The aim of this study was to evaluate the quality of water supplied schools and daycare in the city of São Carlos - SP. We selected 31 schools and kindergartens, and at intervals of 3 months, two water samples taken at three different points - network, tank and fi lter - totaling 186 samples, with an interval of three months, to verify possible differences in sampling points and at different times. The samples were evaluated for the following parameters: presence of total coliform and fecal coliform / E. coli count of heterotrophic bacteria, determination of pH, fl uoride, free residual chlorine, turbidity and color. The largest number of samples outside the standard for coliform was coming from the fi lters and the network, heterotrophic bacteria in most samples was taken out of standard fi lters. In the physical-chemical analysis of samples as many non-standard pH occurred in the network, network, and fl uoride in the fi lter pair in the fi lter to free chlorine and turbidity in the reservoir. The parameter with a larger sample size was inadequate fl uoride. We need more attention to the conservation, cleaning and maintenance of building reservoirs and fi lters in schools and kindergartens of San Carlos, since the water was considered unfi t for consumption.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This article examines new product development (NPD) in small and medium-sized Brazilian enterprises (SMEs) in two technology-based industries: medical devices and process control automation devices. A conceptual model that categorizes factors that contribute to the success of a new product was established. The data were collected from a sample of 62 Brazilian SMEs. The conceptual model was tested to examine the relationships between NPD practices and new product success. Data analysis reveals that new product success in medical device companies is related to organizational characteristics such as NPD proficiency and marketing skills; while in process control automation device companies, they deal in a large degree with product differentiation, innovation and capability to analyze the targeted market. Due to the relatively small sample size, caution should be exercised when interpreting the results.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Objetive: The goal of this review is to present up-to-date information on the prevalence of overweight and obesity and to discuss the evidence regarding the impact of these conditions on the health of mother.Data Collection Method: We conducted a search for articles in the Medline, PubMed and Scielo databases covering the past 5 years, and reviewed the bibliographical references contained in the articles selected. Articles were selected by subjective evaluation in terms of methodology, sample size and year of publication. Summary of evidence: Current information points to a high and growing prevalence of overweight and obesity. We found strong evidence linking excess weight before pregnancy with the development of pregnancy-induced hypertension, gestational diabetes, pregnancy at 41 weeks or over, thromboembolism, cesarean section and puerperal infection. Conclusions: Excess weight in the pre-pregnancy is one of the most important risk factors of maternal health, whose importance increases because it is a modifiable risk factor. The obese pregnant woman should be considered at high risk and it is recommended that women be with the weight as close to normal as possible before conception.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Objetive: The goal of this review is to discuss the evidence regarding the impact of pre-pregnancy overweight and obesity on perinatal outcomes. Data Collection Method: We conducted a search for articles in the Medline, PubMed and Scielo databases covering the past 5 years, and reviewed the bibliographical references contained in the articles selected. Articles were selected by subjective evaluation in terms of methodology, sample size and year of publication. Summary of evidence: We found strong evidence linking excess weight before pregnancy with the development of birth defects, fetal and neonatal deaths and macrosomia,. Conclusions: Excess weight in the pre-pregnancy is an important risk factor for the health of the fetus, whose importance increases because it is a modifiable risk factor.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Electrical conductivity has been proposed as a rapid test to evaluate seed vigor; however, few researches have emphasized methodologies to its use in seeds of medicinal plants, such as chamomile. The objective of the research was to evaluate the electrical conductivity of chamomile seeds affected by different imbibition times and sample size. The evaluations consisted of moisture content, germination and vigor (first count of germination) to seed initial characterization. Then, it was evaluated the electrical conductivity, affected by imbibition time (6, 12, 24 e 48 hours) and seed amount per sample (25, 50, 75, 100). The completely randomized design was used with four replications, arranged as a 4 x 4 factorial. Means were compared by the Tukey test at 5% of probability. It was concluded that the electrical conductivity of chamomile seeds is affected by the number of seeds per sample and imbibition time isolately.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Evaluations of measurement invariance provide essential construct validity evidence. However, the quality of such evidence is partly dependent upon the validity of the resulting statistical conclusions. The presence of Type I or Type II errors can render measurement invariance conclusions meaningless. The purpose of this study was to determine the effects of categorization and censoring on the behavior of the chi-square/likelihood ratio test statistic and two alternative fit indices (CFI and RMSEA) under the context of evaluating measurement invariance. Monte Carlo simulation was used to examine Type I error and power rates for the (a) overall test statistic/fit indices, and (b) change in test statistic/fit indices. Data were generated according to a multiple-group single-factor CFA model across 40 conditions that varied by sample size, strength of item factor loadings, and categorization thresholds. Seven different combinations of model estimators (ML, Yuan-Bentler scaled ML, and WLSMV) and specified measurement scales (continuous, censored, and categorical) were used to analyze each of the simulation conditions. As hypothesized, non-normality increased Type I error rates for the continuous scale of measurement and did not affect error rates for the categorical scale of measurement. Maximum likelihood estimation combined with a categorical scale of measurement resulted in more correct statistical conclusions than the other analysis combinations. For the continuous and censored scales of measurement, the Yuan-Bentler scaled ML resulted in more correct conclusions than normal-theory ML. The censored measurement scale did not offer any advantages over the continuous measurement scale. Comparing across fit statistics and indices, the chi-square-based test statistics were preferred over the alternative fit indices, and ΔRMSEA was preferred over ΔCFI. Results from this study should be used to inform the modeling decisions of applied researchers. However, no single analysis combination can be recommended for all situations. Therefore, it is essential that researchers consider the context and purpose of their analyses.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Major depressive disorder (MDD) trials - investigating either non-pharmacological or pharmacological interventions - have shown mixed results. Many reasons explain this heterogeneity, but one that stands out is the trial design due to specific challenges in the field. We aimed therefore to review the methodology of non-invasive brain stimulation (NIBS) trials and provide a framework to improve clinical trial design. We performed a systematic review for randomized, controlled MDD trials whose intervention was transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) in MEDLINE and other databases from April 2002 to April 2008. We created an unstructured checklist based on CONSORT guidelines to extract items such as power analysis, sham method, blinding assessment, allocation concealment, operational criteria used for MDD, definition of refractory depression and primary study hypotheses. Thirty-one studies were included. We found that the main methodological issues can be divided in to three groups: (1) issues related to phase II/small trials, (2) issues related to MDD trials and, (3) specific issues of NIBS studies. Taken together, they can threaten study validity and lead to inconclusive results. Feasible solutions include: estimating the sample size a priori; measuring the degree of refractoriness of the subjects; specifying the primary hypothesis and statistical tests; controlling predictor variables through stratification randomization methods or using strict eligibility criteria; adjusting the study design to the target population; using adaptive designs and exploring NIBS efficacy employing biological markers. In conclusion, our study summarizes the main methodological issues of NIBS trials and proposes a number of alternatives to manage them. Copyright (C) 2011 John Wiley & Sons, Ltd.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Observations of cosmic rays arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Veron-Cetty Veron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2pt-L, 2pt+ and 3pt methods, each giving a different measure of self-clustering in arrival directions, were tested on mock cosmic ray data sets to study the impacts of sample size and magnetic smearing on their results, accounting for both angular and energy resolutions. If the sources of UHECRs follow the same large scale structure as ordinary galaxies in the local Universe and if UHECRs are deflected no more than a few degrees, a study of mock maps suggests that these three method can efficiently respond to the resulting anisotropy with a P-value = 1.0% or smaller with data sets as few as 100 events. using data taken from January 1, 2004 to July 31, 2010 we examined the 20, 30, ... , 110 highest energy events with a corresponding minimum energy threshold of about 49.3 EeV. The minimum P-values found were 13.5% using the 2pt-L method, 1.0% using the 2pt+ method and 1.1% using the 3pt method for the highest 100 energy events. In view of the multiple (correlated) scans performed on the data set, these catalog-independent methods do not yield strong evidence of anisotropy in the highest energy cosmic rays.