A new and simple analytical method is described for the determination of the IC50 values of the inhibitors of the hydrolysis of acetylcholine (ACh) or acetylthiocholine (ATCh) by cholinesterases. The method is based on monitoring the time course of the pH value during the uninhibited and inhibited reaction. It requires only a pH meter with a suitable pH measuring cell and a small thermostated s...

PURPOSE OF STUDY To measure the pH of the surface of healthy nail plates. PROCEDURES The surface pH of human fingernails and big toenails was measured in vivo using a skin pH meter. The influence of washing, anatomical site (fingers/toes), side (left/right), digit (digits 1-5) and gender was determined. The pH of the nail interior was also measured. RESULTS The pH of the nail plate surface ...

OBJECTIVE In children, excessive ingestion of fluoride from different sources including bottled drinking water and flavoured beverages or soft drinks can lead to the development of dental fluorosis. In addition, the pH level of beverages is important. Low pH can cause dental erosion. In this study we explore the fluoride content and pH level of certain popular beverages available in Malaysian s...

A comparative study on the water quality of interstitial two creeks in Rivers State was conducted. Temperature, pH, Conductivity, Dissolved oxygen, biochemical oxygen demand, Salinity, and Total dissolved solid were checked with an in-situ hand-held multi-meter (The EZODO Multi-meter). (DO) measured a Milwaukee meter while Biochemical Oxygen Demand (BOD) determined by 5-day BOD test (APHA, 2005...

Non-aqueous solvent extraction of acid in papers is described; the process employs a liquid ion-exchanger in chloroform. The amounts of the acid in the so-called acid paper are determined by the normal method of aqueous extraction and by the organic solvent extraction and the values are compared. The results of investigation confirm that the acid content of the acid paper must be determined by ...

BACKGROUND & OBJECTIVES The study was undertaken to characterize factors influencing differential productivity of Anopheles gambiae complex mosquitoes at larval habitats in a rural village in western Kenya. METHODS Longitudinal larval sampling was done using an area sampler for 3 months. Emerged adults were identified to species level morphologically using taxonomic keys and to sub-species by...

In this paper, we present the construction of a reliable and inexpensive pH stat device, by using open-source "OpenPhControl" software, inexpensive hardware (a peristaltic and a syringe pump, Arduino, a step motor…), readily available laboratory devices: a pH meter, a computer, a webcam, and some 3D printed parts. We provide a methodology for the design, development and test results of each par...