Search results for "Multivariate Analysi"

QSPR prediction of retention times of phenylurea herbicides by biological plastic evolution.

2012

A simple/sensitive high-performance liquid chromatographic method, with ultraviolet (UV) detection, was developed for phenylurea-herbicide analysis, which involves preconcentration using solid-phase extraction. Mobile phase was acetonitrile/water at flow-rate of 1 mL.min-1 with direct UV absorbance detection at 210 nm. Analyte separation studied on a C18 column was applied successfully to herbicide analysis in soft drink's brands and tap water. Good linearity/repeatability was observed for all pesticides. Retention times increase as: metoxuron < monuron < diuron < matazachlor < linuron. They are modelled by structure-property relations. The effect of different types of features is analyzed:…

Predictive Factors for Changes in Quality of Life after Steroid Treatment for Active Moderate-to-Severe Graves' Orbitopathy: A Prospective Trial.

2019

&lt;b&gt;&lt;i&gt;Objectives:&lt;/i&gt;&lt;/b&gt; To investigate the predictive factors for changes in the quality of life (GO-QoL) of patients with Graves’ orbitopathy (GO) prior to and after specific treatment. &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; A prospective follow-up study was conducted at an academic tertiary referral orbital center with a joint thyroid-eye clinic on 100 consecutive patients with GO. Before and after the standard 12-week course of weekly intravenous methylprednisolone (cumulative dose 4.5 g), the GO-QoL questionnaire provided by the European Group on Graves’ Orbitopathy (EUGOGO) was completed. Endocrine and ophthalmic assessments were performed at each visi…

Predictive factors of difficulty in lower third molar extraction : a prospective cohort study

2017

Background Several publications have measured the difficulty of third molar removal, trying to establish the main risk factors, however several important preoperative and intraoperative variables are overlooked. Material and Methods A prospective cohort study comprising a total of 130 consecutive lower third molar extractions was performed. The outcome variables used to measure the difficulty of the extraction were operation time and a 100mm visual analogue scale filled by the surgeon at the end of the surgical procedure. The predictors were divided into 4 different groups (demographic, anatomic, radiographic and operative variables). A descriptive, bivariate and multivariate analysis of th…

Two-year sealant survival in a high caries cohort at a graduate pedodontic clinic

2011

Objectives: To assess the efficacy of resin sealants in children aged 6-12 years referred to one graduate pedodontic program located in the Middle East (2009-2010). Study Design: Data from a cohort of 110 patients with at least 2 erupted first permanent molars were included in this study. Dental health status was evaluated using the DMFs/t index. UltraSeal XT® Plus sealants (n=253 applications) were performed in presence of rubber dam isolation and survival carefully inspected and scored at 1 and 2 years. Cross-sectional examination of descriptives and bi/multivariate analysis followed. Results: Majority (63%) were males. Caries were diagnosed in 77.9% of children with only 1% deemed caries…

2013

Annual influenza vaccination is recommended for healthcare workers, but many do not follow the recommendation. The objective of this study was to investigate the factors associated with seasonal influenza vaccination in the 2011–2012 season. We carried out an anonymous web survey of Spanish primary healthcare workers in 2012. Information on vaccination, and knowledge and attitudes about the influenza vaccine was collected. Workers with medical conditions that contraindicated vaccination and those with high risk conditions were excluded. Multivariate analysis was performed using unconditional logistic regression. We included 1,749 workers. The overall vaccination coverage was 50.7% and was h…

Applying a web-based training to foster self-regulated learning — Effects of an intervention for large numbers of participants

2016

Trainings on self-regulated learning (SRL) have been shown to be effective in improving both competence of self-regulated learning and objective measures of performance. However, human trainers can reach only a limited number of people at a time. Web-based trainings (WBT) could improve efficiency, as they can be distributed to potentially unlimited numbers of participants. We developed a WBT based on the process model of SRL by Schmitz and Wiese (2006) and tested it with 211 university students in a randomized control evaluation study including additional process analyses of learning diaries. Results showed that the training had significant effects on SRL knowledge, SRL behavior measured by…

The burden of previous fractures in hip fracture patients. The Break Study

2011

A positive history of fractures in older patients with hip fracture is common. We determined the risk factors associated with a positive history of fractures and the profile of care in hip fracture patients. In the Break Study, we enrolled 1249 women aged ≥60 years, seeking care for a hip fracture. Baseline information included age, body mass index, lifestyle (smoking habit, alcohol consumption), patient's history of fracture after the age of 50 years, family history of fragility fracture and health status (presence of comorbidity, use of specific drugs, pre-fracture walking ability, type of fracture, time to surgery, type of surgery, osteoporosis treatment). In the multivariable model age,…

Combining Pharmacokinetics and Vibrational Spectroscopy: MCR-ALS Hard-and-Soft Modelling of Drug Uptake In Vitro Using Tailored Kinetic Constraints

2022

Raman microspectroscopy is a label-free technique which is very suited for the investigation of pharmacokinetics of cellular uptake, mechanisms of interaction, and efficacies of drugs in vitro. However, the complexity of the spectra makes the identification of spectral patterns associated with the drug and subsequent cellular responses difficult. Indeed, multivariate methods that relate spectral features to the inoculation time do not normally take into account the kinetics involved, and important theoretical information which could assist in the elucidation of the relevant spectral signatures is excluded. Here, we propose the integration of kinetic equations in the modelling of drug uptake…

Multivariate nonparametric tests in a randomized complete block design

2003

AbstractIn this paper multivariate extensions of the Friedman and Page tests for the comparison of several treatments are introduced. Related unadjusted and adjusted treatment effect estimates for the multivariate response variable are also found and their properties discussed. The test statistics and estimates are analogous to the traditional univariate methods. In test constructions, the univariate ranks are replaced by multivariate spatial ranks (J. Nonparam. Statist. 5 (1995) 201). Asymptotic theory is developed to provide approximations for the limiting distributions of the test statistics and estimates. Limiting efficiencies of the tests and treatment effect estimates are found in the…

Multivariate karyomorphometric analysis and taxonomic implications in Allium sect. Cupanioscordum (Amaryllidaceae)

2015

Significant karyological variation occurs amongst different taxa/populations in the A. cupani group. The ancestral diploid chromosome complement is 2n = 16 (x = 8), but populations of A. cupani s.l. also exhibit dysploidy (2n = 14), polyploidy (2n = 4x = 32, 2n = 4x = 30). These different chromosome assets are associated to specific diagnostic morphological characters and well-defined eco-geographical patterns, which cluster different taxa and populations in 5 series (Brullo&al. 1995, 2008). In order to test the impact of inter-and intra-specific variation in chromosome structure on the systematic treatment of the A. cupani group and its contribution to allow comparing and understanding aff…