Inorganic Compounds as Aquaporin Substrates or as Potent Inhibitors: A Coordination Chemistry Point of View

2016 ◽  
pp. 297-318 ◽  
Author(s):  
Angela Casini ◽  
Andreia de Almeida
Keyword(s):  
Coordination Chemistry ◽  
Inorganic Compounds ◽  
Point Of View

Addendum

1986 ◽  
Vol 227 (1246) ◽  
pp. 145-145
Keyword(s):  
Primary Production ◽  
Electron Acceptor ◽  
Deep Sea ◽  
Hydrothermal Vents ◽  
Inorganic Compounds ◽  
Anaerobic Bacteria ◽  
Deep Ocean ◽  
Extended Period ◽  
Point Of View ◽  
The Common

Review Lecture. The chemosynthetic support of life and the microbial diversity at deep-sea hydrothermal vents. Proc. R. Soc. Lond . B 225, 277-297 (1985). In this lecture, the chemosynthetic base of the food chain supporting rich deep-sea ecosystems around hydrothermal vents, was claimed to represent a primary production of organic carbon independent of sunlight. I received several comments criticizing this point of view for neglecting the fact that oxygen is the required electron acceptor in the metabolism of the eukaryotic part of the vent communities. I agree. The independence of light was, however, mentioned in connection with a catastrophic darkening of the globe’s surface. A temporary absence of photo­synthetic oxygen production might well be overcome for an extended period of time by the ‘aerobic’ deep-sea vent animals, given the minute consumption of oxygen relative to its huge total quantity available in deep ocean waters. In a permanent absence of light, however, the existence of eukaryotic organisms, as we know them, will depend on an oxygen-producing process such as photosynthesis. Populations of anaerobic bacteria, on the other hand, may well persist and differentiate into prokaryotic ecosystems in permanent darkness as long as the geothermal provision of H 2 and CO 2 continues. Physical chemists were troubled by the use of the term ‘source of energy’ for reduced inorganic compounds, such as H 2 S, in chemosynthesis because the actual amount of free energy available depends on the reaction with the oxidant. It is certainly true that the common equalization of the terms ‘electron donor’ and ‘energy source’ in microbial physiology does not take the specific type of electron acceptor into account. They are used as terms of convenience. In my discussion of deep-sea chemosynthesis as a form of primary production, the emphasis on terrestrial chemical ‘sources of energy’ was meant to illustrate the contrast to the use of solar energy which does not only supply oxygen as the most efficient electron acceptor but also the common electron donors, organic as well as inorganic, for all non-phototrophic life in surface waters and on the continents.

scholarly journals Functionalization and Characterization of Silicon Nanowires for Sensing Applications: A Review

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 999
Author(s):  
Samuel Ahoulou ◽  
Etienne Perret ◽  
Jean-Marie Nedelec
Keyword(s):  
Silicon Nanowires ◽  
Radio Frequency Identification ◽  
Inorganic Compounds ◽  
Silicon Nanowire ◽  
High Surface ◽  
Volume Ratio ◽  
Point Of View ◽  
Sensing Applications ◽  
Frequency Identification

Silicon nanowires are attractive materials from the point of view of their electrical properties or high surface-to-volume ratio, which makes them interesting for sensing applications. However, they can achieve a better performance by adjusting their surface properties with organic/inorganic compounds. This review gives an overview of the main techniques used to modify silicon nanowire surfaces as well as characterization techniques. A comparison was performed with the functionalization method developed, and some applications of modified silicon nanowires and their advantages on those non-modified are subsequently presented. In the final words, the future opportunities of functionalized silicon nanowires for chipless tag radio frequency identification (RFID) have been depicted.

Aperiodic Crystals

2018 ◽  
Author(s):  
Ted Janssen ◽  
Gervais Chapuis ◽  
Marc de Boissieu
Keyword(s):  
Physical Properties ◽  
Inorganic Compounds ◽  
Point Of View ◽  
Periodic Arrays ◽  
New Class ◽  
Modulated Phases ◽  
Lattice Periodicity ◽  
Wide Range ◽  
Unit Cells ◽  
Aperiodic Crystals

Until the 1970s all materials studied consisted of periodic arrays of unit cells, or were amorphous. In the following decades a new class of solid state matter, called aperiodic crystals, has been found. It is a long-range ordered structure, but without lattice periodicity. It is found in a wide range of materials: organic and inorganic compounds, minerals (including a substantial portion of the earth’s crust), and metallic alloys, under various pressures and temperatures. Because of the lack of periodicity the usual techniques for the study of structure and physical properties no longer work, and new techniques have to be developed. This book deals with the characterization of the structure, the structure determination, and the study of the physical properties, especially the dynamical and electronic properties of aperiodic crystals. The treatment is based on a description in a space with more dimensions than three, the so-called superspace. This allows us to generalize the standard crystallography and to look differently at the dynamics. The three main classes of aperiodic crystals, modulated phases, incommensurate composites, and quasicrystals are treated from a unified point of view which stresses the similarities of the various systems. The book assumes as a prerequisite a knowledge of the fundamental techniques of crystallography and the theory of condensed matter, and covers the literature at the forefront of the field.

scholarly journals CHEMICAL TERMINOLOGY AND NOMENCLATURE OF COORDINATION CHEMISTRY

2018 ◽  
pp. 6-8
Author(s):  
A. Golub
Keyword(s):  
Inorganic Chemistry ◽  
Coordination Chemistry ◽  
Chemical Elements ◽  
Inorganic Compounds ◽  
Rapid Development ◽  
Chemical Compounds ◽  
Original Language ◽  
The World ◽  
Iupac Nomenclature ◽  
Difficult Times

Ukrainian chemical terminology is one of the most advanced in the world, due to the rapid development after the rise of independence and it basing on the latest developments of IUPAC terminology and nomenclature. First of all, it is owed to the fundamental principles developed by our predecessors, who, in the difficult times of Soviet power, overcoming the impenetrable walls of imperial resistance, nevertheless tried to promote the development of chemical terminology in the course of time, and sometimes ahead of the advanced international and national terminology of others, even free countries. The orientation on the international terminology standards was chosen to build a new Ukrainian terminology and nomenclature at the Department of Inorganic Chemistry of Shevchenko University of Kyiv in the 50's – 70's of the 20th century The basic requirements for the terminology and nomenclature of inorganic chemistry were formulated, which can be used as a guide for the development of Ukrainian chemical terminology and nomenclature nowadays: 1.Chemical terms should correspond to the modern meaning. 2. The nomenclature of inorganic compounds and elements should be consistent with the foundations of inorganic chemistry. 3. The nomenclature should be developed in close connection with the systematics of chemical elements and compounds. 4. The new Ukrainian nomenclature in inorganic chemistry should be based on the international nomenclature. 5. When creating a new nomenclature it is necessary to take into account the specifics of the Ukrainian language. 6. The nomenclature should be rational and give unambiguous names of chemical compounds. 7. The transfer of terms and names from other languages should be created according to the phonetic principle and transcribed from the original language. The most important principles of Ukrainian chemical terminology and nomenclature of coordination chemistry have been discussed, examples of the possibilities of adaptation of the IUPAC nomenclature rules on the basis of the Ukrainian language have been demonstrated.

The Geosciences Applied to Lunar Exploration

1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green
Keyword(s):  
Lunar Surface ◽  
Probable Mechanism ◽  
Point Of View ◽  
Lunar Exploration ◽  
Geological Model ◽  
Apply Geophysics ◽  
Surface Features ◽  
The Impact

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.

How a sheperd guides a sheep herd?

1984 ◽  
Vol 75 ◽  
pp. 331-337
Author(s):  
Richard Greenberg
Keyword(s):  
Point Of View ◽  
Single Ring ◽  
Damping Effects ◽  
Ring Particle

ABSTRACTThe mechanism by which a shepherd satellite exerts a confining torque on a ring is considered from the point of view of a single ring particle. It is still not clear how one might most meaningfully include damping effects and other collisional processes into this type of approach to the problem.

The growth of mica polytypes as studied by conventional and high-resolution TEM

1983 ◽  
Vol 41 ◽  
pp. 174-177
Author(s):  
A. Baronnet ◽  
M. Amouric
Keyword(s):  
Water Pressure ◽  
Point Of View ◽  
Temperature Fields ◽  
Natural Occurrence ◽  
Growth Mechanisms ◽  
Long Period ◽  
High Resolution Tem ◽  
Layer Stacking ◽  
Experimental Works ◽  
Potential Use

The origin of mica polytypes has long been a challenging problem for crystal- lographers, mineralogists and petrologists. From the petrological point of view, interest in this field arose from the potential use of layer stacking data to furnish further informations about equilibrium and/or kinetic conditions prevailing during the crystallization of the widespread mica-bearing rocks. From the compilation of previous experimental works dealing with the occurrence domains of the various mica "polymorphs" (1Mr, 1M, 2M1, 2M2 and 3T) within water-pressure vs temperature fields, it became clear that most of these modifications should be considered as metastable for a fixed mica species. Furthermore, the natural occurrence of long-period (or complex) polytypes could not be accounted for by phase considerations. This highlighted the need of a more detailed kinetic approach of the problem and, in particular, of the role growth mechanisms of basal faces could play in this crystallographic phenomenon.

Radiation Damage in Ceramics

1982 ◽  
Vol 40 ◽  
pp. 600-603
Author(s):  
T. E. Mitchell ◽  
M. R. Pascucci ◽  
R. A. Youngman
Keyword(s):  
Radiation Damage ◽  
Outer Space ◽  
Point Of View ◽  
Nuclear Waste Storage ◽  
Waste Storage ◽  
Storage Media ◽  
Transmission Electron ◽  
Fundamental Point ◽  
Small Defect ◽  
Present Understanding

1. Introduction. Studies of radiation damage in ceramics are of interest not only from a fundamental point of view but also because it is important to understand the behavior of ceramics in various practical radiation enyironments- fission and fusion reactors, nuclear waste storage media, ion-implantation devices, outer space, etc. A great deal of work has been done on the spectroscopy of point defects and small defect clusters in ceramics, but relatively little has been performed on defect agglomeration using transmission electron microscopy (TEM) in the same kind of detail that has been so successful in metals. This article will assess our present understanding of radiation damage in ceramics with illustrations using results obtained from the authors' work.

Structural aspects of osmoregulation in porphyra

1978 ◽  
Vol 36 (2) ◽  
pp. 412-413
Author(s):  
C. Wiencke ◽  
A. Lauchli
Keyword(s):  
Culture Medium ◽  
Point Of View ◽  
Chemical Fixation ◽  
Cellular Organization ◽  
Osmotic Adaptation ◽  
Osmotic Balance ◽  
Activity Of Enzymes ◽  
Osmotic Agents ◽  
Vacuolar System ◽  
Structural Aspects

Osmoregulatory mechanisms in algae were investigated mainly from a physiological point of view (KAUSS 1977, HELLEBUST 1976). In Porphyra two osmotic agents, i. e. floridoside/isofloridoside (KAUSS 1968) and certain ions, such as K+ and Na+(EPPLEY et al. 1960) are considered for osmotic balance. Accumulations of ions (particularly Na+) in the cytoplasm during osmotic adaptation is improbable, because the activity of enzymes is generally inhibited by high ionic concentrations (FLOWERS et al. 1977).The cellular organization of Porphyra was studied with special emphasis on the development of the vacuolar system under different hyperosmotic conditions. Porphyra was cultivated at various strengths of the culture medium ASP 12 (PROVASOLI 1961) ranging from normal to 6 times concentrated (6x) culture medium. Por electron microscopy freeze fracturing was used (specimens fixed in 2% glutaraldehyde and incubated in 30% glycerol, preparation in a BALZERS BA 360 M apparatus), because chemical fixation gave poor results.

Elucidation of block boundaries as the dissolution channels in hydrated cement

1978 ◽  
Vol 36 (1) ◽  
pp. 484-485
Author(s):  
N.V. Belov ◽  
U.I. Papiashwili ◽  
B.E. Yudovich
Keyword(s):  
Liquid Phase ◽  
Grain Boundaries ◽  
Benzoyl Peroxide ◽  
Phase Contrast ◽  
Active Role ◽  
Point Of View ◽  
Hardened Cement ◽  
Hydrated Cement ◽  
Hardened Cement Paste

It has been almost universally adopted that dissolution of solids proceeds with development of uniform, continuous frontiers of reaction.However this point of view is doubtful / 1 /. E.g. we have proved the active role of the block (grain) boundaries in the main phases of cement, these boundaries being the areas of hydrate phases' nucleation / 2 /. It has brought to the supposition that the dissolution frontier of cement particles in water is discrete. It seems also probable that the dissolution proceeds through the channels, which serve both for the liquid phase movement and for the drainage of the incongruant solution products. These channels can be appeared along the block boundaries.In order to demonsrate it, we have offered the method of phase-contrast impregnation of the hardened cement paste with the solution of methyl metacrylahe and benzoyl peroxide. The viscosity of this solution is equal to that of water.

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