2 resultados para Discarding of books, periodicals, etc

em National Center for Biotechnology Information - NCBI


Relevância:

100.00% 100.00%

Publicador:

Resumo:

This list of 424 books and 77 journals is intended as a selection guide for print literature to be used in a library supporting allied health educational programs or allied health personnel in either an academic or health care setting. Because of the impossibility of covering the large number and wide variety of allied health professions and occupations, the recommended publications are focused primarily on the educational programs listed and recognized by the American Medical Association and other accrediting bodies. Books and journals are categorized by subject; the book list is followed by an author/editor index, and the subject list of journals by an alphabetical title listing. Items suggested for initial purchase (167 books and 31 journals) are indicated by asterisks. To purchase the entire collection of books and journals (2000 subscriptions) would require an expenditure of about $31,970. The cost of only the asterisked items totals $12,515.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Mineral surfaces were important during the emergence of life on Earth because the assembly of the necessary complex biomolecules by random collisions in dilute aqueous solutions is implausible. Most silicate mineral surfaces are hydrophilic and organophobic and unsuitable for catalytic reactions, but some silica-rich surfaces of partly dealuminated feldspars and zeolites are organophilic and potentially catalytic. Weathered alkali feldspar crystals from granitic rocks at Shap, north west England, contain abundant tubular etch pits, typically 0.4–0.6 μm wide, forming an orthogonal honeycomb network in a surface zone 50 μm thick, with 2–3 × 106 intersections per mm2 of crystal surface. Surviving metamorphic rocks demonstrate that granites and acidic surface water were present on the Earth’s surface by ∼3.8 Ga. By analogy with Shap granite, honeycombed feldspar has considerable potential as a natural catalytic surface for the start of biochemical evolution. Biomolecules should have become available by catalysis of amino acids, etc. The honeycomb would have provided access to various mineral inclusions in the feldspar, particularly apatite and oxides, which contain phosphorus and transition metals necessary for energetic life. The organized environment would have protected complex molecules from dispersion into dilute solutions, from hydrolysis, and from UV radiation. Sub-micrometer tubes in the honeycomb might have acted as rudimentary cell walls for proto-organisms, which ultimately evolved a lipid lid giving further shelter from the hostile outside environment. A lid would finally have become a complete cell wall permitting detachment and flotation in primordial “soup.” Etch features on weathered alkali feldspar from Shap match the shape of overlying soil bacteria.