Missing data due to limit of detection and limit of quantification is a common obstacle in epidemiological and biomedical research. We are interested in methodologies that provide unbiased and efficient estimates of these missing data while using popular statistical software. We describe a multiple imputation (MI) procedure for cross-sectional and longitudinal data which examines the sources of...

BACKGROUND Aflatoxin M1 (AFM1), a carcinogenic substance is found in milk and dairy products. The effect of season and type of dairy products on AFMi level in northern Iran was investigated in this study. METHODS Three hundred samples (each season 75 samples) including raw and pasteurized milk, yoghurt, cheese, and cream samples were collected from three distinct milk producing farms. The sam...

Most currently proteomic studies use data-dependent acquisition with dynamic exclusion to identify and quantify the peptides generated by the digestion of biological sample. Although dynamic exclusion permits more identifications and higher possibility to find low abundant proteins, stochastic and irreproducible precursor ion selection caused by dynamic exclusion limit the quantification capabi...

5,7-Dimethoxyflavone (5,7-DMF), a natural flavonoid abundant in many plants, has been reported to have many beneficial pharmacological effects, including strong chemopreventive and chemosensitizing properties, anti-oxidant, cardiovascular protectant, and anti-inflammatory activities. However, to date 5,7-DMF was evaluated mainly in vitro and its pharmacokinetics (PK) in vivo remains largely unk...

Isothermal calorimetry operated in gas perfusion mode (IGPC) is often used to quantify the amorphous content of pharmaceutical powders. Typically, the calibration line is constructed using the heat of crystallisation as the sample is exposed to high levels of a plasticising vapour. However, since the physical form to which the amorphous fraction crystallises may be dependent on the presence of ...

A simple and specific reverse phase high performance liquid chromatographic method was developed and validated for the estimation of clozapine in tablet dosage forms. A Lachrom C 18 column having 250 x 4 i.d in an isocratic mode with mobile phase containing acetonitrile: phosphate buffer (70:30% v/v) was used. The flow rate was 1.0 ml/min and the retention time of clozapine was found to be 3.06...

This work describes the development, validation and stable studies of a new, simple and reliable UV spectroscopy procedure for the analysis of eflornithine hydrochloride. A new rapid, precise, accurate, specific and simple UV Spectrophotometric analytical method was validated to assay eflornithine hydrochloride (DFMO) in parenteral. Measurements were taken at λmax 283 using ethanol as the solve...

INTRODUCTION A novel and simple isocratic reverse phase liquid chromatographic (RP-LC) method was developed for the quantitative determination of antioxidant-butylated hydroxy toluene (BHT) in paricalcitol hard gelatin capsule. In the paricalcitol capsule BHT concentration is very low. This method is precisely able to estimate BHT at low concentration at about 0.0039 μg/mL and to separate BHT f...

We report the first rapid ultra-high performance liquid chromatographic (UHPLC) enantiomeric reversed-phase separation of rasagiline mesylate and its tartrate salts using a Chiralpak® AGP column (50 mm × 2.1 mm, 5 μm) as a stationary phase. This method was developed as an alternative to the usage of previously reported normal-phase chiral LC columns for isomer separation. Our method is based on...

The detection and quantification of hepatitis B virus (HBV) DNA are essential for the diagnosis and treatment of chronic HBV infection. The use of real-time PCR assays for HBV DNA quantification is strongly recommended. The goal of this study was to evaluate the intrinsic characteristics and clinical performance of version 2.0 (v2.0) of the Cobas AmpliPrep/Cobas TaqMan (CAP/CTM) assay, a fully ...