842 Journal of Chemical Education • Vol. 84 No. 5 May 2007 • www.JCE.DivCHED.org Thin-layer chromatography (TLC) is often used as a qualitative method. It can determine the number of components in a mixture, verify the identity of substances, monitor the progress of a reaction, or ascertain the effectiveness of a purification. Since TLC is so easy and practical, many chemists frequently use TLC...

Timed Logic Conformance (TLC) is a bisimulation-style partial order relationship deened over the statespace of Timed Safety Automata (TSA) with real-valued clocks. In contrast to timed simulation, Calculus of Timed Reene-ment (CTR), and Time-Abstracted bisimulation, TLC de-nes when one system is an acceptable implementation of another by asymmetric bisimulation-style requirements for speciicati...

An immunohistochemical study of cytokeratins (CK) in a case of trichilemmal carcinoma (TLC). CK expression showed the presence of CK 1, 10, 14 and 17, suggesting that TLC differentiates toward follicular infundibulum. In a comparison of CK expression between TLC and trichilemmoma, the absence of CK 15 and 16 in TLC may be related to transformation from trichilemmoma to TLC. Trichilemmal carcino...

Restriction of total lung capacity (TLC) is found in some obese subjects, but the mechanism is unclear. Two hypotheses are as follows: 1) increased abdominal volume prevents full descent of the diaphragm; and 2) increased intrathoracic fat reduces space for full lung expansion. We have measured total intrathoracic volume at full inflation using magnetic resonance imaging (MRI) in 14 asymptomati...

Objective: The aims of the present study were to screen actinobacteria with high potential ability produce secondary metabolites that have inhibitory activity against plant pathogenic fungi, Magnaporthe oryzae. Production was analysis by thin-layer chromatography and bioautography assay.
 Methods: Screening selection Streptomyces sp. morphological, cultural, physiological, biochemical char...

Fruits and vegetables are an essential part of a healthy diet, providing humans with vitamins, phytonutrients, minerals. They significantly vulnerable, however, to post-harvest diseases caused by numerous fungal bacterial pathogens. These pathogens can cause significant quantitative qualitative losses from harvest consumption during the handling storage processes. Chemical fungicides commonly u...

Correspondence result that FRC TLC and RV TLC ratios are disproportionately elevated. We have speculated about the infl uence of erroneously elevated volume ratios on the interpretation of published COPD outcome studies. For example, Fessler et al 2 developed a model in which plethysmographically measured RV TLC ratios predicted improvement in FEV 1 following lung volume reduction surgery (LVRS...

A temporal logic of causality (TLC) was introduced by Alur, Penczek, and Peled in [1]. It is basically a linear time temporal logic interpreted over Mazurkiewicz traces which allows quantification over causal chains. Through this device one can directly formulate causality properties of distributed systems. In this paper we consider an extension of TLC by strengthening the chain quantification ...

BACKGROUND We developed a simple and inexpensive thin-layer chromatography (TLC) assay for semiquantitative detection of saliva concentrations of nevirapine in resource-limited settings. The method was validated in an African target population. METHODS Paired plasma and saliva nevirapine concentrations were assayed by high-performance liquid chromatography (HPLC); saliva concentrations of nev...