Dialkyl amides of L-valine, L-isoleucine, and L-tert-leucine (2) are excellent chiral auxiliaries for the construction of quaternary stereocenters at ambient temperature. Enaminoesters 3, prepared from these auxiliaries 2 and Michael donors 1, undergo a copper-catalyzed asymmetric Michael reaction with methyl vinyl ketone (MVK, 4) to afford products 5 in 70-90% yield and 90-99% ee (enantiomeric...

Clothing textiles come under the category of other commodities pursuant to the Foods and Other Commodities Act. They require neither notification nor marketing authorisation which means that the public authorities do not have information about individual textile auxiliaries or dyes used. The working group "Health Assessment of Textile Auxiliaries and Dyes" within the working group "Textiles" of...

Biological markers or biomarkers are defined as indicators that signal events in biological systems (human body) or samples. A biomarker is not used as diagnosis test, but as an indicator of a disease or biological alteration. The biomarkers are classified in three types: 1) exposure; 2) susceptibility and 3) biomarkers of effect. For biomarkers of fluoride the examples would be respectively: 1...

BACKGROUND This study aimed to determine knowledge, attitude and practice of airborne and droplet isolation precautions among Dental Health Professionals (DHPs) (dental students, interns, practitioners and auxiliaries) during the outbreak of MERS (Middle East Respiratory Syndrome), corona virus infection in Riyadh city, Saudi Arabia. MATERIAL AND METHODS A cross-sectional survey was conducted...

Professional dental auxiliaries emerged in the early 20th century in the United States of America and quickly spread to Europe and other regions of the world. In Brazil, however, oral health technicians (OHTs), who occupy a similar role as dental hygienists, had a long journey before the occupation achieved legal recognition: Brazilian Law 11.889, which regulates this occupation in the country,...

Spencer (1991) and Sadler (1997) argue that there are two diierent phenomena that have been grouped together as`contracted auxiliaries'. On the one hand are the syllabic reduced auxiliaries that are unselective in what they attach to. On the other hand, there are nonsyllabic reduced auxiliaries that exhibit lexical idiosyncrasy, stem allomorphy, and word-internal phonological processes. Sadler ...

Hedging academic claims has been recognized as one of integral pragmatic features of academic writing in which most EFL academic writers seem to face substantial problems. Explicit instruction has been proposed by some scholars as an effective approach to make EFL writers aware of the importance, different forms, and pragmatic functions of hedging devices some of which are polysemous and polypr...

THE GREAT importance of medical auxiliaries in primary medical care and in community health schemes is now being increasingly recognized by those who are involved in the planning of health services for developed and developing countries alike. Schemes employing very large numbers of auxiliaries are already well established in Russia1 and in China.2 The major need for auxiliaries is, in the firs...