A fast method was developed by ultra high performance liquid chromatography (UHPLC) for simultaneous determination of polyphyllin I and polyphyllin II. Chemometric analyses including principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) based on UHPLC chromatography were used to evaluate 38 batches from six species of Paris. Variable importance of projectio...

Este trabalho propôs um novo método para a determinação de dipirona (DIP) em soluções orais farmacêuticas, usando medidas de transflectância no infravermelho próximo (NIR) e calibração multivariada. A faixa de estudo foi de 300,0 a 569,2 mg mL de DIP. O melhor modelo PLS foi obtido com 2 variáveis latentes e apresentou erros médios quadráticos de calibração e de previsão (RMSEC e RMSEP) iguais ...

In this paper we ask three questions. Do PLS path estimates compensate for measurement error? Do they capitalize on chance? And is PLS able to more accurately weight measurement indicators so as to make path estimations more accurate? The evidence is quite convincing that PLS path estimates do have all three of these characteristics. Our analysis suggests, however, that measurement error has by...

The ultimate goal of any prescribed medical therapy is to achieve desired outcomes for patients. However, patient non-compliance has long been a major problem detrimental to patients’ health and thus is a concern of all healthcare providers. Patient trust in doctors and patient-doctor communication have been identified as critical factors influencing patient compliance. Nevertheless, little is ...

Com o objetivo de melhor entender as informações paramétricas contidas em descritores bidimensionais (2D) e tridimensionais (3D), os escores de 87 descritores 2D e 798 variáveis 3D (ALMOND) obtidos de uma série de 5998 compostos de interesse em química medicinal, foram analisados através de análise de componentes principais. A fração de variância explicada (r) e a validação cruzada (q) para set...

Acute leukemia is a critical neoplasm of white blood cells. In order to differentiate between the metabolic alterations associated with two subtypes of acute leukemia, acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML), we investigated the serum of ALL and AML patients and compared with two controls (healthy and aplastic anemia) using (1)H NMR (nuclear magnetic resonance) spect...

We aimed to explore the potential effects of Xinfeng capsule (XFC) on urine metabolic profiling in adjuvant-induced arthritis (AA) rats by using gas chromatography time-of-flight mass spectrometry (GC-TOF/MS). GC-TOF/MS technology was combined with multivariate statistical approaches, such as principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogona...

BACKGROUND Principal Component Analysis (PCA) and Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) are powerful statistical modeling tools that provide insights into separations between experimental groups based on high-dimensional spectral measurements from NMR, MS or other analytical instrumentation. However, when used without validation, these tools may lead invest...

For SMEs, responsiveness to changes is a critical survival capability. Practitioners believe that IT infrastructure flexibility contributes to responsiveness, yet empirical evidence is sparse. The purpose of this research is to empirically test the relationship between IT infrastructure flexibility, which is measured on four dimensions, and IT responsiveness. Two research questions are answered...

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Principles of classifi cation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 The classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 Main categories of classifi cation methods ...