OBJECTIVE Laboratory tests including optical platelet aggregometry (OPA), platelet function analyser (PFA-100), and thromboxane B2 (TXB2) metabolite levels have been used to define aspirin resistance. This study characterised the prevalence of aspirin resistance in patients with ischaemic heart disease (IHD) and investigated the concordance and repeatability of these tests. DESIGN, SETTING AN...

Background: PFA-100 is a point-of-care assay that evaluates platelet reactivity in high-shear-stress conditions by measuring the closure time (CT) of a membrane aperture. When determined with a collagen/epinephrine cartridge (CEPI), the CT is usually prolonged by aspirin. Studies of the predictive value of a short PFA-100CTCEPI for ischemic events in aspirin-treated patients have given variable...

Objectives. Preswallow pharyngeal bolus presence is evident in patients with oropharyngeal dysphagia. Pressure flow analysis (PFA) using high resolution manometry with impedance (HRMI) with AIMplot software is a method for objective interpretation of pharyngeal and upper esophageal sphincter (UES) pressures and bolus flow patterns during swallowing. This study aimed to observe alterations in PF...

[formula: see text] Aminocyclodextrins (ACDs), perfunctionalized at the 6-position with amino groups, bind phosphonoformate (PFA) diesters and accelerate acyl transfer reactions with high efficiency at neutral pH. Aminolysis and esterolysis are accelerated and hydrolysis of PFA diesters is catalyzed by ACDs. PFA diesters have significant antiviral activity. The rapid reactions observed with ACD...

In recent years, Chinese enterprises have conducted cross-border M&A more and more frequently. Cross-border M&A becomes an important way to achieve internationalization strategy for Chinese enterprises. In this paper, taking China’s A shares listed companies’ cross-border M&A in 2011 as samples, using the factor analysis method to conduct Principal Component Analysis of multiple financial indic...

This paper examines logistics services and strategic dimensions in Taiwanese (Republic of China, ROC) maritime ®rms. This is done by means of a review of previous studies and personal interviews; data collection has also included a questionnaire survey. A factor analysis and a principal components analysis were conducted in order to assess the degree of importance of a large number of service a...

We introduce R-PFA, a new model for predicting whether or not a student will answer an item correctly based on the student’s history of practice. The key idea in R-PFA is to represent history as a recentcy-weighted proportion of correct responses. In an evaluation on a dataset from the Assistments tutoring system, we find that R-PFA improves predictive accuracy over other logistic regression mo...

ABSTRACT We introduce a statistical method for the decomposition of data sets into planes. With the help of principal component analysis or factor analysis the data are presented in a lower-dimensional space. The factors spanning this new co-ordinate system are rotated afterwards in that sense to fulfill the idea of simple structure, extended to two dimensions. The resulting planes which are sp...

Usually, principal components analysis is carried out by calculating the eigenvalues and eigenvectors of the correlation matrix. With N cases and P variables, if we write X for the N × P matrix which has been standardised so that columns have zero mean and unit standard deviation, we find the eigenvalues and eigenvectors of the P × P matrix X.X (which is N or (N − 1) times the correlation matri...

BACKGROUND One of the key issues in determining the quality of water in rivers is to create a water quality control network with a suitable performance. The measured qualitative variables at stations should be representative of all the changes in water quality in water systems. Since the increase in water quality monitoring stations increases annual monitoring costs, recognition of the stations...