On Biomineralization

1989 ◽  
Author(s):  
Heinz A. Lowenstam ◽  
Stephen Weiner
Keyword(s):  
Medical Research ◽  
Design Principles ◽  
Mineral Formation ◽  
Medical Problems ◽  
Basic Principles ◽  
Mineralized Tissues ◽  
Mineralization Processes ◽  
Archaeological Artifacts

Focusing on the basic principles of mineral formation by organisms, this comprehensive volume explores questions that relate to a wide variety of fields, from biology and biochemistry, to paleontology, geology, and medical research. Preserved fossils are used to date geological deposits and archaeological artifacts. Materials scientists investigate mineralized tissues to determine the design principles used by organisms to form strong materials. Many medical problems are also associated with normal and pathological mineralization. Lowenstam, the pioneer researcher in biomineralization, and Weiner discuss the basic principles of mineral formation by organisms and compare various mineralization processes. Reference tables listing all known cases in which organisms form minerals are included.

Biomineralization Processes

1989 ◽  
Author(s):  
Heinz A. Lowenstam ◽  
Stephen Weiner
Keyword(s):  
Continuous Spectrum ◽  
Convergent Evolution ◽  
Common Ancestor ◽  
External Medium ◽  
The Other ◽  
Mineral Formation ◽  
Mineralization Processes ◽  
Established Fact ◽  
Different Sources ◽  
Almost Continuous

The large number of different minerals formed by organisms from almost 50 different phyla described in Chapter 2 should in itself discourage anyone from searching for the mechanism of biomineralization. On the other hand, the survey of macromolecules used by many organisms to control mineralization (Chapter 2), even though limited primarily to carbonate- and phosphate-bearing mineralized hard parts, shows that similar and rather unusual acidic glycoproteins and proteoglycans are widely utilized in biomineralization. This raises the possibility that many organisms may have adopted common approaches or strategies for regulating mineral formation. We do not know whether this arose as a result of divergence from a common ancestor or is a product of convergent evolution in which many different phyla independently began utilizing similar macromolecules for controlling mineralization (see Chapter 12). Either way we view the diversity in biomineralization as the product of a very broad and almost continuous spectrum of processes that organisms use to control mineralization. This ranges from no apparent control at one end to, it seems, control over every detail at the other. However, this is achieved by a fairly limited number of different basic processes used in various combinations and ways to produce a unique final product. This last statement is, we readily admit at this point in time, more an act of faith than an established fact. In this chapter we will try to identify and/or speculate about some of these basic processes. We will draw upon material from many different sources, and, in particular, we will refer whenever possible to the more detailed descriptions of mineralization processes given in the chapters that follow. As a consequence, this chapter may also be used by the reader as a guide toward more discriminating reading on selected topics in the remainder of the book. The spectrum of biomineralization processes can in principle be easily divided into cases in which control is exercised in some way over mineralization and those in which it is not. In practice the differentiation is not that simple as all organisms do exercise some control at one level or another, even if it simply involves, for example, removing from the cell some undesirable metabolic end-product or ion that combines with another ion in the external medium and precipitates.

Disaster medicine and response: Optimizing life-saving potential

2018 ◽  
Vol 13 (4) ◽  
pp. 253-264 ◽  
Author(s):  
Mehmet Sukru Sever, MD ◽  
Giuseppe Remuzzi, MD ◽  
Raymond Vanholder, MD
Keyword(s):  
Disaster Medicine ◽  
Regional Hospital ◽  
Medical Problems ◽  
Basic Principles ◽  
Demand And Supply ◽  
Medical Interventions ◽  
Medical Response ◽  
Life Saving ◽  
Routine Medical Practice ◽  
Mass Disasters

Background: Natural and technological mass disasters strike densely populated areas on a regular basis, causing ever growing numbers of deaths and injured, economical losses, social problems, and damage to the environment.Objective of the review: This review aims to provide a comprehensive idea about the spectrum of main problems, essentially presenting a number of basic principles to save as many lives as possible after natural and man-made mega disasters.Discussion: Medical problems following disasters may be acute, acute-on-chronic, or chronic; they appear from the disaster period up till long thereafter. All these problems may be nonspecific, or specific for particular disaster types. Decreasing death toll after mass disasters can be accomplished by preparations before, and effective medical response after disasters. These interventions should be considered at both national/governmental and regional/hospital levels. Disaster medicine, the art and science of providing healthcare to the victims, differs significantly from routine medical practice because of disparities between demand and supply of rescue and healthcare, the need for unusual medical interventions, and the occurrence of ethical and legal dilemmas.Conclusions: Adherence to the principles of disaster medicine, is vital to minimize the extent of medical, logistic, ethical, and legal problems, and saving as many lives as possible.

scholarly journals Basic Principles in the Design of Spider Silk Fibers

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1794
Author(s):  
José Pérez-Rigueiro ◽  
Manuel Elices ◽  
Gustavo R. Plaza ◽  
Gustavo V. Guinea
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Spider Silk ◽  
Design Principles ◽  
Tensile Behavior ◽  
Original Design ◽  
Basic Principles ◽  
Silk Fibers ◽  
The Relationship ◽  
Selection Of

The prominence of spider silk as a hallmark in biomimetics relies not only on its unrivalled mechanical properties, but also on how these properties are the result of a set of original design principles. In this sense, the study of spider silk summarizes most of the main topics relevant to the field and, consequently, offers a nice example on how these topics could be considered in other biomimetic systems. This review is intended to present a selection of some of the essential design principles that underlie the singular microstructure of major ampullate gland silk, as well as to show how the interplay between them leads to the outstanding tensile behavior of spider silk. Following this rationale, the mechanical behavior of the material is analyzed in detail and connected with its main microstructural features, specifically with those derived from the semicrystalline organization of the fibers. Establishing the relationship between mechanical properties and microstructure in spider silk not only offers a vivid image of the paths explored by nature in the search for high performance materials, but is also a valuable guide for the development of new artificial fibers inspired in their natural counterparts.

Mineral Induction by Matrix from Mineralized Biological Tissues

1990 ◽  
Vol 218 ◽  
Author(s):  
Miles A. Crenshaw
Keyword(s):  
Calcium Binding ◽  
Soluble Fraction ◽  
Adsorbed Layer ◽  
Biological Tissues ◽  
Insoluble Fraction ◽  
Mineral Formation ◽  
Mineralized Tissue ◽  
Biological Matrices ◽  
Structural Framework ◽  
Mineralized Tissues

AbstractThe polymeric matrix of mineralized tissues controls the form and structure of the mineral that is deposited. This matrix has an insoluble fraction which provides a structural framework for the mineralized tissue, and a soluble fraction which is rich in polyanionic macromolecules. One hypothesis envisages mineral being nucleated by an atomic dimensional matching between crystal lattice and anionic spacing in the polyanionic macromolecules. An alternate hypothesis considers that fixed polyanions provide a surface for an adsorbed layer, enriched in lattice ions by ionotropy, to induce mineral formation from the metastable body fluids.We found that soluble matrix polyanions, immobilized by attachment to insoluble substrates, would induce mineral from metastable solutions. The insoluble substrates included natural and synthetic hydrogels not derived from mineralized tissues. Whether the polyanions were prepared from apatitic or CaCO3 tissues, the mineral induced was independent of the source and was determined by the composition of the solution. Other immobilized, calcium-binding, polyanionic macromolecules, obtained from non-mineralizing tissues, also induced mineral.These and other data indicate that mineral induction by biological matrices is less specific than implied in the atomic dimensional matching extension of the epitaxial hypothesis.

Basic Principles of Hose Design

1969 ◽  
Vol 42 (3) ◽  
pp. 666-674 ◽  
Author(s):  
W. I. Harkleroad
Keyword(s):  
Fluid Pressure ◽  
Length Change ◽  
Design Principles ◽  
Basic Principles ◽  
Design Concepts ◽  
Outer Cover ◽  
Control Forces ◽  
Reinforcement Angle ◽  
Internal Pressures ◽  
And Control

Abstract Fundamentals of hose design have not changed with the introduction of new and improved component materials. Hose consists of three basic elements which are tube, reinforcement, and outer cover—with each serving a primary function. The tube or inner liner contains and resists the fluid conveyed and transmits forces created by the internal pressures to the strength member. The reinforcement or strength member contains the forces created by the fluid pressure. The outer cover protects hose reinforcement and resists external environment and damage. This paper is primarily concerned with the design concepts of the strength member or reinforcement as a functional component to resist and control forces created in service. Design principles relating to reinforcement angle, burst strength, and length change under pressure are presented for various hose styles. Braided, spiral, wrapped, loomed, wrapped ply and knitted hose styles are reviewed and compared. Reinforcement materials, their types, relative strengths and advantages are summarized. Examples of specific applications of hose are presented to illustrate hose design principles in action in industry.

scholarly journals Next-generation sequencing (NGS) methods and their application in clinical microbiology, infectology and epidemiology

2021 ◽  
Vol 18 (4) ◽  
pp. 26-32
Author(s):  
V. M. Mitsura
Keyword(s):  
Next Generation Sequencing ◽  
Personalized Medicine ◽  
Infectious Diseases ◽  
Medical Research ◽  
Clinical Microbiology ◽  
Next Generation ◽  
Basic Principles ◽  
Treatment And Prevention ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

This review presents basic principles and methods of next-generation sequencing (NGS) and discusses a number of the latest papers on the possibilities, principles and stages of NGS, as well as the application of NGS in medical research, particularly, clinical microbiology and infectious diseases, epidemiology. The development of NGS technologies will allow improving the results of diagnostics, treatment and prevention of infectious diseases and opens up new prospects for personalized medicine.

Chordata

1989 ◽  
Author(s):  
Heinz A. Lowenstam ◽  
Stephen Weiner
Keyword(s):  
Calcium Phosphate ◽  
Navigation System ◽  
Tooth Enamel ◽  
Carbonate Minerals ◽  
Single Class ◽  
Iron Minerals ◽  
Phosphate Mineral ◽  
Mineralized Tissues ◽  
Mineralization Processes ◽  
Enamel Mineralization

In the field of biomineralization the phylum Chordata is the most intensively studied, as one of its subphyla, the Craniata, includes our own species. The Craniata are often referred to as the vertebrates, a term that alludes to the importance of the endoskeleton in denning the essential character of these animals. The phylum Chordata also contains three other subphyla, only one of which has members that form mineralized hard parts. They belong to the Urochordata or tunicates. In fact, mineralization is confined to several families of a single class of urochordates, the Ascidiacea. Table 9.1 is a compilation of the known biogenic minerals formed by members of the Chordata, together with the sites at which they form and their presumed functions. The table includes no less than 17 different minerals, which should dispel any notion that mineralization in the chordates is synonymous with "calcium phosphate" deposition. It is, of course, true that the mineralized skeletal hard parts of most of the Craniata or vertebrates contain a calcium phosphate mineral, usually in the carbonated form called dahllite. However, the vertebrates also form four different carbonate minerals that are most commonly found in the vestibulary apparatus (see Chapter 10). They form three different iron minerals, which includes magnetite found in the navigation system of various vertebrate genera. The Ascidiacea also form a diverse array of minerals. Interestingly, however, their diversity is essentially confined to one class, the Pyuridae, which form no less than six different minerals, including two phosphate minerals. In this chapter we first describe biomineralization processes in the Ascidiacea followed by detailed discussions of mineralization processes in the Chordata or vertebrates. For convenience, the section on vertebrate mineralization is divided according to the major mineralized tissues: bone (dentin), cartilage, and tooth enamel. Mineralization in the vestibulary apparatus is discussed in Chapter 10.

Sign in / Sign up

Export Citation Format

Share Document