Continuous importance

The search for suitable protecting groups of carbonyl and hydroxyl functions has been of continuous importance in steroid chemistry. As a result of these efforts a good selection of protecting groups is now available for use in organic synthesis. 

The continued importance of hydrogen in the development of experimental and theoretical chemistry is further illustrated by some of the dates listed in the Panel on the page opposite. 

Hofmann AF (1999) The continuing importance of bile acids in liver and intestinal disease. Arch Intern Med 159 2647-2658... 

Jaussi A. Continuing importance of the clinical approach. Observations on a regional collaboration between general practitioners, internists and cardiologists. Schweiz Med Wochenschr 1994 124 2049-52. 

At the state level, there is growing awareness of the essential role of nuclear power in meeting Clean Air Act requirements, and the continued importance of emission free nuclear energy in the future. Just ask the state of Georgia, which is concerned about the... 

The continued importance of 3-lactam ring systems in medicine has encouraged a number of research groups to investigate their synthesis via a nitrone cycloaddition protocol. Kametani et al. (60-62) reported the preparation of advanced intermediates of penems and carbapenems including (+)-thienamycin (29) and its enantiomer (Scheme 1.7). They prepared the chiral nitrone 30 from (—)-menthyl... 

Although the continued importance of acetylene in contributing to the output of... 

There has been a phenomenal growth of interest in theoretical simulations over the past decade. The concomitant advances made in computing power and software development have changed the way that computational chemistry research is undertaken. No longer is it the exclusive realm of specialized theoreticians and supercomputers rather, computational chemistry is now accessible via user-friendly programs on moderately priced workstations. State-of-the-art calculations on the fastest, massively parallel machines are continually enlarging the scope of what is possible with these methods. These reasons, coupled with the continuing importance of solid acid catalysis within the world s petrochemical and petroleum industries, make it timely to review recent work on the theoretical study of zeolite catalysis. 

The scarcity of reviews1 and recent interest in thiochromanones and related compounds calls for a comprehensive summary of this area of heterocyclic chemistry. The apparent similarity between these systems and the naturally occurring chromanones, chromones (flavones), chromenes, etc., is responsible for the continued importance of these sulfur heterocycles. Chemical Abstracts (through November, 1973) has been employed as the principal reference source and nomenclature guide for this review. 

The continued importance of research and development with air-sensitive compounds, coupled with the general lack of publications or undergraduate instruction on the techniques used in this area, prompted us to revise this monograph. The level of presentation is designed to make the book useful to the chemist who is beginning work in the field. In addition, considerable technical data and information are given that should aid chemists at all levels of proficiency in the design of experiments. 

Moser M, Setaro J. Continued importance of diuretics and beta-adrenergic blockers in the management of hypertension. Med Clin North Am. 2004 88 167-187. 

From the receptor cells nerves pass through the olfactory lobes at the front end of the brain direct to the central basal region, the part known as the "limbic system." This forms part of our deep-seated unconscious mind, being associated with the control of emotion and sexual activity, as well as with feelings of pleasure. In evolutionary terms it is also the oldest part of the brain, providing evidence of the early and continuing importance of the sense of smell in animal behavior. 

This collection of the state-of-the-art papers emphasizes the continuing importance of industrial-scale production, separation, and recovery of transplutonium elements. Americium (At. No. 95) and curium (At. No. 96) were first isolated in weighable amounts during and immediately after World War II. Berkelium and californium were isolated in 1958 and einsteinium in 1961. These five man-made elements, in each case, subsequently became available in increasing quantities. 

Because of the continued importance of porphyrin synthesis in biomedical, chemical, and industrial applications many new routes for synthesizing porphyrinic macrocycles have been developed and excellent overview articles have been published on the topic. To highlight the role that porphyrin synthesis plays, the entire volume 1 of the Porphyrin Handbook is devoted to the preparation of porphyrinic macrocycles. In this volume, Smith, for example. 

China has begun to produce some safflower oil. Chinese varieties have traditionally been under 30% oil content, since the bulk of the research there was aimed at improved seed and floret yields. Safflower produced in the far west and northern parts of China is high in linoleic levels, and Japan has continually imported small quantities of Chinese seed because of this. With China s emergence into the world s economic and political venues, its safflower could become more important as it produces or imports better varieties of seed and improves its internal transportation system. 

Nevertheless, aniline nucleophiles have made continued, important contributions in organic synthesis and in studies of organic reaction mechanisms, which constitute the major subjects of this chapter. 

Plutonium is manufactured in megagram quantities neptunium, americium, and curium in kilogram quantities californium in gram amounts berkelium in 100-milligram amounts and einsteinium in milligram quantities. Chemical separations play a key role in the manufacture of actinide elements, as well as in their recovery, and analysis in the nuclear fuel cycle. This collection of timely and state-of-the-art topics emphasizes the continuing importance of actinide separations processes. 

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