The synthesis of bacterial protein in the rumen of lactating cows fed on purified carbohydrates, with urea and ammonium salts as the sole sources of nitrogen, can be increased, through feed adaptation, to a level adequate not only for the maintenance of the cow but also for a relatively high milk production. The best annual milkyield per cow on the experimental feedhas, so far, been 4217 kilograms, calculated as standard milk (684 kilocalories per kilogram of milk). The composition of the test milk is similar to that of normal fat- and proteinrich milk. Fractionation of casein and serum proteins of test milk and normal milk by different methods demonstrated the similarity of the proteins of the two milks. The normal or higher concentrations of the water-solublevitamins in test milk show that the biosynthesis of these vitamins in the rumen is vigorous. The flavor of the two milks is very similar-proof that biosynthesis of the effective flavor compounds of milk occurs in the body of the cow. The only component of test milk whose composition, when small amounts of vegetable oil have been fed, has differed from that of normal milk is the fat. The studies of milk production on the experimental feed have opened up new possibilities for investigating the biosynthesis of different milk components. The studies are also of practical importance: Since the vigorous biosynthesis of proteins from simple nitrogen compounds in the rumen of test-feed-adapted cows has been demonstrated, there are greater possibilities for studying the replacement of protein by urea. In countries where there are plenty of forests, part of the feed of cows can be made up of certain wood products-for instance, hemicellulose and cellulose of low quality. The new findings may also be of value in the dry areas of the globe, where milk would be of vital significance for improving the nutrition of the population.

https://science.sciencemag.org/content/sci/153/3744/1603.full.pdf

Milk production of cows on protein-free feed.

The crystal structures of the [A(1)(2)][A(2)(3)](BO(4))(3)X apatites and the related compounds [A(1)(2)][A(2)(3)](BO(5))(3)X and [A(1)(2)][A(2)(3)](BO(3))(3)X are collated and reviewed. The structural aristotype for this family is Mn(5)Si(3) (D8(8) type, P6(3)/mcm symmetry), whose cation array approximates that of all derivatives and from which related structures arise through the systematic insertion of anions into tetrahedral, triangular or linear interstices. The construction of a hierarchy of space-groups leads to three apatite families whose high-symmetry members are P6(3)/m, Cmcm and P6(3)cm. Alternatively, systematic crystallographic changes in apatite solid-solution series may be practically described as deviations from regular anion nets, with particular focus on the O(1)-A(1)-O(2) twist angle phi projected on (001) of the A(1)O(6) metaprism. For apatites that contain the same A cation, it is shown that phi decreases linearly as a function of increasing average ionic radius of the formula unit. Large deviations from this simple relationship may indicate departures from P6(3)/m symmetry or cation ordering. The inclusion of A(1)O(6) metaprisms in structure drawings is useful for comparing apatites and condensed-apatites such as Sr(5)(BO(3))(3)Br. The most common symmetry for the 74 chemically distinct [A(1)(2)][A(2)(3)](BO(4))(3)X apatites that were surveyed was P6(3)/m (57%), with progressively more complex chemistries adopting P6(3) (21%), P3; (9%), P6 (4.3%), P2(1)/m (4.3%) and P2(1) (4.3%). In chemically complex apatites, charge balance is usually maintained through charge-coupled cation substitutions, or through appropriate mixing of monovalent and divalent X anions or X-site vacancies. More rarely, charge compensation is achieved through insertion/removal of oxygen to produce BO(5) square pyramidal units (as in ReO(5)) or BO(3) triangular coordination (as in AsO(3)). Polysomatism arises through the ordered filling of [001] BO(4) tetrahedral strings to generate the apatite-nasonite family of structures.

/pdf/structural-derivation-and-crystal-chemistry-of-apatites-14z08hfu2j.pdf

Structural derivation and crystal chemistry of apatites.

Apatite, the most common phosphate mineral, is generally described by the formula Ca5(PO4)3(OH,F,Cl) or, more completely with regard to its usual description in P 63/ m symmetry, by the unit cell content [Ca4][Ca6][(PO4)6][OH,F,Cl]2. An earlier volume of the Reviews series (Kohn et al. 2002) has dealt with the mineralogy and crystallography of apatite sensu stricto (Hughes and Rakovan 2002) and the diverse compounds that adopt apatite or apatite-like structures (Pan and Fleet 2002; Huminicki and Hawthorne 2002). In addition, apatite compilations have appeared at regular intervals (Wychoff 1965; McConnell 1973; Nriagu and Moore 1984; Brown and Constantz 1994; Elliott 1994) as the breadth of apatite chemistry has expanded and the level of understanding of its importance with respect to the mineral, materials, environmental, and biological sciences increased. It is not therefore, the purpose of this chapter to restate these excellent reviews, but rather, to focus on microporosity in apatites, a feature which allows ion conduction and exchange, and that is proving to be an important consideration for fashioning synthetic analogues of these minerals in technologically advantageous ways.

The notion of apatite as an industrially significant microporous mineral is not new. In 1944, V. M. Goldschmidt who had studied apatite deposits in Scandinavia and at that time had found refuge from war-ravaged Europe at the Macaulay Institute of Soil Research, Aberdeen (Kauffman 1997; McIntyre 2004) persuaded C. A. Beevers to undertake a new refinement of fluorapatite. The results collected in the seminal paper of Beevers and McIntyre (1946), lead not only to the most accurate crystallographic data available at that time, but also provided the first overview of [Ca4][Ca6][(PO4)6][F] …

Apatite - An Adaptive Framework Structure

Elucidating the underlying molecular mechanisms of protein folding and function is a very exciting and active research area, but poses significant challenges. This is due in part to the fact that existing experimental techniques are incapable of capturing snapshots along the 'reaction coordinate' in question with both sufficient spatial and temporal resolutions. In this regard, recent years have seen increased interests and efforts in development and employment of site-specific probes to enhance the structural sensitivity of spectroscopic techniques in conformational and dynamical studies of biological molecules. In particular, the spectroscopic and chemical properties of nitriles, thiocyanates, and azides render these groups attractive for the interrogation of complex biochemical constructs and processes. Here, we review their signatures in vibrational, fluorescence and NMR spectra and their utility in the context of elucidating chemical structure and dynamics of protein and DNA molecules.

/pdf/site-specific-spectroscopic-reporters-of-the-local-electric-shb5nisbkp.pdf

Site-Specific Spectroscopic Reporters of the Local Electric Field, Hydration, Structure, and Dynamics of Biomolecules.

Aspergillus fumigatus is the most important species in Aspergillus causing infective lung diseases. This species has been reported to produce a large number of extrolites, including secondary metab...

Metabolomics of Aspergillus fumigatus.

/pdf/the-mass-spectra-of-some-aliphatic-lactones-417a5va8m5.pdf

The Mass Spectra of Some Aliphatic Lactones.

/pdf/x-ray-studies-on-some-alkali-and-alkaline-earth-chromates-v-9op3vtttt8.pdf

X-Ray Studies on Some Alkali and Alkaline-Earth Chromates(V).

/pdf/alkyl-cyanates-iv-infrared-and-nuclear-magnetic-resonance-47a7dn78zw.pdf

Alkyl Cyanates. IV. Infrared and Nuclear Magnetic Resonance Spectra.

/pdf/the-structure-of-trypacidin-1f0ycfh6b6.pdf

The structure of trypacidin.

/pdf/synthesis-of-dilithium-s-alpha-picolylphosphorothioate-and-t85vlbw9xw.pdf

A. Kjær

Papers

The Mass Spectra of Some Aliphatic Lactones.

X-Ray Studies on Some Alkali and Alkaline-Earth Chromates(V).

Alkyl Cyanates. IV. Infrared and Nuclear Magnetic Resonance Spectra.

The structure of trypacidin.

Synthesis of Dilithium S-alpha-Picolylphosphorothioate and Barium N-Acetylcysteamine S-Phosphate.