Secondary Constituents Research Articles

Tidal spectroscopy of a coastal area: observed and simulated tides of the Lake Maracaibo system

In Section 1 of this paper a thorough analysis of tide gauge data is presented for the Lake Maracaibo system. Local resonance for semidiurnal constituents and strong meteorological effects at S 1 and S 2 frequencies are clearly identified from the admittance curves. Section 2 is dedicated to the comparison between different ways of finite difference modelling these tidal constituents depending on the bottom friction parameterization: (i) The simulation of each constituent alone with quadratic bottom friction gives good results only for the M 2 wave (the dominant wave) which indicates that the secondary constituents cannot be simulated without taking into account the M 2 wave. (ii) The simulation of the secondary constituents with a quasi-linearized bottom friction taking into account the M 2 wave gives good results for both diurnal and semidiurnal constituents in different areas. (iii) Large duration simulation was also performed in order to reproduce the whole tidal spectrum together. This latter simulation gives similar results to the previous one for the semidiurnal and the diurnal astronomical constituents, and, in addition, non-linear constituents such as 2MN 2 are obtained through this simulation. From these comparisons it can be concluded that the technique of quasi-linearization of the bottom friction gives good results and is recommended instead of large duration simulation when the non-linear compound constituents can be ignored. Sea-level variations were predicted from the simulated harmonic constituents and compared with observations. Velocity fields were also predicted and qualitatively compared with available field measurements, showing a good agreement.

Some observations on the chemistry and taxonomy of the tribe Bignonieae

Chemotaxonomy of 12 taxa of the tribe Bignonieae investigated resemble one another in the presence of syringly radicals, caffeic acid, gentisic acid, vanillic acid unknown phenolic compound L(68/69) uniformly positive activity of polyphenolase and overlapping incidence of several classes of secondary chemical constituents, phenolic compounds and unusual (non-protein) amino acids. The quantified chemical data indicate that Bignonieae are homogenous taxon and the taxa are closely related. The present study does not support the creation of Pyrostegineae and Oroxyleae.

Nucleation of microcellular foam: Theory and practice

AbstractMicrocellular polymer foams exhibit greatly improved mechanical properties as compared to standard foams due to the formers' small bubble size. Microcellular foams have bubbles with diameters on the order of 10 microns, volume reductions of 30 to 40 percent, and six or seven times the impact strength of solid parts. They are produced through the use of thermodynamic instabilities without the use of foaming agents. This method leads to a very uniform cell size throughout a part's cross section. A theoretical model for the nucleation of microcellular foams in thermoplastic polymers has been developed and experimentally confirmed. This model explains the effect of various additives and processing conditions on the number of bubbles nucleated. At levels of secondary constituents below their solubility limits, an increase in the concentration of the additive or the concentration of gas in solution with the polymer increases the number of bubbles nucleated. Nucleation in this region is homogeneous. Above the solubility limit of additives, nucleation is heterogeneous and takes place at the interface between second phase inclusions and the polymer. The number of bubbles nucleated is dependent on the concentration of heterogeneous nucleation sites and their relative effect on the activation energy barrier to nucleation. In the vicinity of the solubility limit, the two mechanisms compete.

Phytochemical evaluation ofCassia obtusifolia L. andCassia tora L.

Cassia obtusifolia andCassia tora are distinct in several important phytochemical characters. Obtusin, obtusifolin and stigmasterol are confined only toCassia obtusifolia and chrysoobtusin toCassia tora. They also differ in their amino acid constituents. Cyotine y-hydroxyarginine and aspartic acid are present inCassia tora but absent inCassia obtusifolia. Hystidine, which is present inCassia obtusifolia is absent inCassia tora. Also there was no natural hybridization betweenCassia obtusifolia andCassia tora and thus showing complete genetical segregation. This supports their treatment as two distinct species. The presence of 3 additional secondary constituents, stigmasterol, obtusin and obtusifolin inCassia obtusifolia suggest thatCassia tora was derived fromCassia obtusifolia.

Protein Banding Patterns in the Ramalina Siliquosa Group

AbstractThe value of primary chemical compounds correlated with known secondary chemistry and morphological variation within the Ramalina siliquosa group has been investigated. A hundred specimens were collected on two different occasions from 13 different populations on the Swedish west coast during April 1984. Protein extracts were prepared from 27 on secondary constituents identified and morphologically analysed populations. The protein bandings were performed by means of isoelectric focusing. Twenty-two different banding patterns were analysed since two were destroyed during preparation and three others yielded weak patterns. The results indicated that three different banding pattern types could be discerned: type A originated from material containing norstictic acid, stictic acid, norstictic acid in combination with stictic acid and on acid-deficient material; type B originated from material containing salazinic acid or salazinic acid in combination with protocetraric acid; and type C originated from material containing salazinic acid, protocetraric acid, salazinic acid in combination with protocetraric acid or on acid-deficient material. Material of banding type A belonged morphologically to R. cuspidata (Ach.) Nyl. and material of banding types B and C to R. siliquosa (Hudson) A. L. Smith. Seasonal and developmental factors can, however, affect the production of both primary and secondary constituents. Since there are no obvious morphological differences between the different chemical races within R. siliquosa s. str. and as material of salazinic acid in combination with protocetraric acid yielded both type B and type C banding patterns, the results do not support a taxonomy in the R. siliquosa group recognizing more than two species.

A Critical Review of Section 8 (BS 5930)—Soil and Rock Description

Abstract BS 5930 proposes fundamental changes to current practice in the description of soils and rocks. The paper reviews these changes and suggests alternative proposals which provide a workable reconciliation between the aims of the new Code and current practical soil and rock description. The main changes made by the Code and the authors' recommendations are: The distinction between fine soil and coarse soil solely on grading is rejected in favour of description according to engineering behaviour. The distinction between silt and clay solely on the basis of the A-line is supplemented with additional terms for borderline cases. Simplification and extension of terminology for description of secondary constituents of mixed soils. Rejection of proposed weathering classification for rocks as inapplicable, in favour of current practice. Clarification of rock nomenclature to conform with geological conventions. The changes to current practice made by BS 5930 are considered to be a retrograde step and could lead to confusion and errors. The paper also considers the process of sample description and attempts to clarify the definition of terms employed in fracture logging of rock core. The paper calls for a revision and reissue of Section 8 of the new Code.

THE NUCLEATION OF MICROCELLULAR THERMOPLASTIC FOAM: PROCESS MODEL AND EXPERIMENTAL RESULTS

Abstract Microcellular polymer foams exhibit greatly improved mechanical properties compared to standard foams due to the formers' small bubble size. Typical microcellular foams have bubbles with diameters on the order of 10 microns and volume reductions of 30 to 40%. The presence of these bubbles acts to increase the impact strength of a microfoamed structure to six or seven times that of solid parts of the same linear dimensions due to crack blunting and increased craze initiation in the cell walls. The first step in designing techniques to manufacture parts of microcellular foam is a complete understanding of the bubble nucleation process. To this end, a theoretical model for the nucleation of microcellular foams in thermoplastic polymers has been developed and experimentally confirmed. This model explains the effect of various additives and processing conditions on the number of bubble nucleated. At levels of secondary constituents below their solubility limits, an increase in the concentration of the additive or the concentration of gas in solution with the polymer increases the number of bubbles nucleated. Nucleation in this region is homogeneous. Above the solubility limit of additives, nucleation is heterogeneous and takes place at the interface between second phase inclusions and the polymer. The number of bubbles nucleated is dependent on the concentration of heterogeneous nucleation sites and their relative effect on the activation energy barrier to nucleation.

Design Considerations for Liquefied Natural Gas Plants in South East Asia

Design Considerations for Liquefied Natural Gas Plants in South East Asia

La genèse des argiles pédologiques. Ses implications minéralogiques, physico-chimiques et hydriques / Clay genesis In pedological conditions. Mineraloglcal, physico-chemical and hydric implications

After characterizing the main modes of climatic weathering from a geochemical and mineralogical point of view, this article deals with the relationship between clays and the conditions of the atmospheric environment. Their distribution over the Earth is treated by mean of a schematic presentation. The second part is devoted to a careful examination of the implications : mineralogical (relationship between the pedologicai typology and the nature of secondary constituents), physicochemical (origin of the surface charge and mode of electric compensation), hydric (relationship between hygrométrie data on the one hand, and water content as well as clay textural characteristics on the other hand).

The discharge of primary and secondary granules during immune phagocytosis by normal and chronic granulocytic leukaemia polymorphonuclear neutrophils

The two types of granule in polymorphonuclear neutrophils may have distinct functions. The primary granule enzymes are responsible for killing and digesting ingested micro-organisms while the secondary granule constituents may have regulatory functions outside the cell. This hypothesis is supported by finding that during immune phagocytosis of a yeast, nearly all of the neutrophil's secondary granule vitamin B12-binding protein is lost from the cell and 80% can be accounted for in the medium. Much less of the primary granule enzymes, beta-glucuronidase and acid phosphatase, are lost from the cells and very little can be detected in the medium. Lysozyme is a constituent of both types of granule and its behaviour is intermediate. There is no difference in the release of these granule constituents from chronic granulocytic leukaemia neutrophils compared with normal neutrophils.

Plant Cell Cultures and their Biotechnological Potential

The potential of plant cell suspension cultures for the biotechnological production of high-cost, plant-specific compounds is critically evaluated. The basic roles of nutrient media and phytohormones are described followed by a description of the recent progress in mass cultivation of plant cell cultures as measured by biomass and doubling time. The accumulation of secondary constituents in cell cultures is reviewed and methods for the selection of high-producing strains are described. The essential features of the selection strategy are the establishment of cell cultures from high-producing plants and a sensitive assay (e.g. radio-immunoassay) for the screening of microcolonies grown on petri dishes. The accumulation of biosynthetic intermediates of secondary constituents in cell culture strains will possibly lead to the isolation of novel compounds. Similarly, the appearance of different pattern of secondary compounds in plants and their derived cell cultures will make screening of cell cultures with pharmaceutically oriented bioassays a worthwhile procedure. Considerable emphasis has been placed on biotransformation reactions of various steroids and particularly the 12-β-hydroxylation of cardiac glycosides. The present status of the latter reactions as carried out by selected strains of Digitales lanata in fermenter systems with β-methyldigitoxin is described. Studies of the position-specific glucosylation of 6,7-dihydroxycoumarin to esculin are presented and competitive side reactions of phenolic substrates described. The growth-phase dependent expression of enzymic reactions in cell cultures is exemplified by recent studies on an acylglucoside transferase. Finally, the new methodology of immobilized cells has recently been applied to plant cell cultures. Preliminary results on anthraquinone and alkaloid biosynthesis as well as biotransformation reactions are discussed.

On the definition of cannabinoids: botanical? chemical? pharmacological?

Cannabinoids (or presumed synonyms such as cannabinols or cannabis-like agents) have been variously defined in botanical, chemical, or pharmacological terms, with unfortunate consequences. Botanical definitions include inactive substances such as cannabigerol, as well as alkaloids and other secondary constituents of Cannabis sativa, but exclude synthetics such as levonantradol and nabilone. Chemical definitions include inactive close analogs of THC but exclude a growing number of substances structurally remote from THC that share its actions. Pharmacological definitions have depended on relatively nonspecific or vague behavioral endpoints. However, animal testing methodology has recently been developed that can identify and quantify agents that share THC's unique subjective effects. To avoid preexisting ambiquity in the word cannabinoids, the term cannabimimetics has been coined to include all such agents, regardless of origin or structure. Such a classification emphasizes research toward improved biological selectivity and therapeutic advance. While no totally noncannabimimetic agents with potent analgesic effects have yet been identified among derivatives of THC, selectivity has been uncovered for levonantradol, HHC (racemic-9-nor, 9-beta-OH-hexahydrocannabinol) and several structurally related compounds.

Selection of Winter Forage by Subarctic Browsing Vertebrates: The Role of Plant Chemistry

Plant palatability frequently moderates vertebrate herbivore forage selection patterns (e.g. 72, 73, 103, 104, 111, 137, 179, 195). There is, however, considerable debate as to which plant chemical characteristics control palatability (e.g. 9, 42, 110, 118, 120, 216). On the one hand, forage proximal nutritional quality is believed to be of primary importance (e.g. 18, 51, 103, 114, 130, 133, 137, 161, 173, 215). On the other, there is increasing speculation that forage selection patterns are largely the result of avoidance of plant secondary constituents that are antagonistic to vertebrate herbivore fitness (e.g. 1, 2, 9, 12, 25, 49, 112, 116, 120, 141, 153, 165, 199, 200). In this paper we examine these alternatives for a specific system. We consider the interface between subarctic browsing vertebrates and woody browse plants during winter and attempt to answer the following questions: During winter do subarctic browsing vertebrates (a) feed preferentially upon plant tissues that contain relatively high concentrations of proximal nutrients or energy, or (b) consistently avoid plant tissues that

Effects of Serum and Cations on the Selective Release of Granular Proteins from Human Neutrophils during Phagocytosis

The extracellular release from human neutrophils of the primary (azurophil) granule constituents, myeloperoxidase (MPO), chymotrypsin-like cationic protein (CCP), collagenase and lysozyme, and the secondary (specific) granule constituents, lactoferrin and lysozyme, was measured during ingestion of staphylococcus protein-A-IgG complexes. In buffer, lactoferrin release was consistently higher than that of the other protein. In serum, lactoferrin release increased concomitantly with ingestion, whereas the rate of lysozyme and especially of MPO release were stimulated to a higher degree than ingestion. Magnesium (0.5--2 mM) was more potent than calcium (0.5--2 mM) in promoting release but these cations worked synergistically. Zinc (0.5--4 mM) was found to be a potent and selective inhibitor of collagenase release. Manganese (0.25--4 mM), which inhibited the ingestion of SpA-IgG complexes, also inhibited release of CCP, collagenase, lysozyme and MPO, but actually stimulated lactoferrin release. The data suggests that lactoferrin and lysozyme may be confined to distinct granule populations or else released in a different fashion from the granules. When the effects on release of primary granule proteins are concerned it is suggested that the dissociation of binding of various agents to an anionic granule matrix may be affected differently by various cations.

Ecogeographic distribution of secondary constituents in Parthenium (compositae)

Over 20 taxa of the genus Partenium (Compositae) representing four sections or five ecological groupings from throughout the Americas, were examined for sesquiterpene lactones, flavonoids and alkaloids. The tropical thorn-forest, arborescent members (sect. Parthenichaeta) were found to contain three different sesquiterpene lactone types and derivatives of the flavonols; quercetin, kaempferol and quercetagetin. The desert shrubs were remarkable for their high production of methylated quercetagetin flavonols and alkaloids, but lacked any appreciable amounts of sesquiterpene lactones. The temperate, submontane perennials (sect. Bolophytum), contained lactones and flavonols in extremely low concentrations. The herbaceous annuals (sect. Argyrochaeta) contained pseudoguaianolides only and together with quercetin, and kaempferol O- glycosides . The herbaceous perennials contained twice as many lactones and flavonoids as the annuals. It is suggested that the ecogeographical distribution of secondary products in Parthenium is probably a result of adaptive responses to various physical and biotic factors (herbivore pressure) in the environment.

アルミニウム合金の被削性に及ぼす鋳造組織の影響

The dendrite arm spacing, one of variable of cast structure, or cooling rate during solidification was applied as a criterion for machinability of various Al-Cu, Al-Si and Al-Mg casting alloys in turning tests. Refining the dendrite arm spacing leads to reduction in tool wear in accordance to the empirical equation VB = kDn, where D is dendrite arm spacing, VB flank wear of the tool, and k and n constants. Roughness of finished surfaces is remarkably increased with decreasing the cooling rate during solidification as a result of coarsening of secondary constituents. Decreasing the cooling rate remarkably increases the number of chips. The cutting force is independent of the cooling rate.

CHEMISCHE RASSEN BEI ALKALOIDPFLANZEN

Secondary metabolites but not primary products (e. g. amino acids, nucleic acids) are used as markers to characterize infraspecific chemical taxa in the plant kingdom. About SO years ago the term secondary metabolites was introduced by F. Czapek in his essay on alkaloids. The role of secondary constituents (including alkaloids) in general metabolism of plants is controversial. Some aspects are critically reviewed.

Composition of turpentine from Pinus edulis wood oleoresin

Monoterpenoids and sesquiterpenoid hydrocarbons of Pinus edulis wood oleoresin were analyzed by chromatographic and spectroscopic methods. Monoterpenoid hydrocarbons (20·3%) were composed mainly of α-pinene, with camphene, β-pinene, 3-carene, sabinene, myrcene, limonene, β-phellandrene, trans-ocimene and terpinolene in secondary to trace amounts. Oxygenated terpenoids (0.28%) contained bornyl acetate and verbenone as major constituents, and linalool, camphor, terpinene-4-ol, citronellyl acetate, borneol, neral, α-terpineol, citronellol, nerol, and geraniol in smaller amounts. Oleoresin contained 1·1% of acetogenins, composed mainly of ethyl caprylate. Sesquiterpenoid hydrocarbons were high (5·7%) in oleoresin) and were composed of germacrene D as a major constituent (36·6%), of γ-amorphene, α-copaene, and longifolene as secondary constituents (5–20%), and β-farnesene, α- and γ-murolenes, β 1-, γ-, δ-, and ε-cadinenes, α-amorphene, δ-guaiene, sibirene, α-cubebene, β-copaene, β-ylangene, sativene, cyclosativene, β-bourbonene, α- and γ-humulenes, caryophyllene, α-longipinene and longicyclene in smaller amounts. Composition of P. edulis and of P. monophylla turpentines was found to be similar, with percentage of ethyl caprylate being the best distinguishing criterion.

Ａｌ‐０．６％Ｆｅ合金連続鋳造塊におけるもみの木組織の生成

A study was made on the formation of 'fir-tree' structure during D. C. casting of Al-Fe alloys. Al-Fe alloys containing 0.58%Fe and less than 0.01%Si were unidirectionally solidified. The alloys were also D. C. cast. The cooling rate during unidirectional solidification was measured by thermal analysis, while the cooling rate during D. C. casting was estimated through measurements of the dendrite arm spacing of the ingots. Identification of constituent phases were carried out by optional microscopy, electron microscopy and X-ray diffraction, and some of their chemical properties were discussed.The results obtained are summarized as follows:1) Al3Fe, Al6Fe and AlmFe (a body-centered tetragonal Al-Fe phase8)) were identified as secondary constituents. They were found to be formed in the following ranges of cooling rate:Al3Fe: less than 2°C/secAl6Fe: from 2 to 20°C/secb.c.t.AlmFe: more than 20°C/sec.2) Al3Fe and b.c.t. AlmFe were oxidized during anodizing in 15%H2SO4 solution, while Al6Fe did not undergo oxidation. Al3Fe and b.c.t. AlmFe were etched to appear dark-brown by 0.5%HF solution, while in the case of Al6Fe, only a slightly grey tint was detected.3) The microstructure of the D. C. cast ingots was divided into the four regions corresponding to different sizes of dendrite cells and to different constituent phases. The first, these cond and the third regions were outside the 'fir-tree' structure, while the fourth region was inside. Body-centered tetragonal AlmFe and a small amount of Al3Fe were secondary constituents in the first region which solidified very rapidly. Al3Fe phase existed in the second and third regions which solidified more slowly. Al6Fe phase was an interdendritic phase in the fourth region which solidified fairly fast.4) The cause of formation of 'fir-tree' structure seems to be attributable to the fact that the cooling rate during solidification varies from the surface to the center of D. C. cast ingots. In other words, the cause is likely attributed to macroscopic segregation of different types of intermetallic compounds.

Some notes on the distribution of alkaloids in the plant kingdom

In the search for a natural system of classification, various secondary plant constituents have been considered to have taxonomic significance. Among such substances are the alkaloids. I would like to offer some brief comments and observations on their distribution in the plant kingdom based on a recent review of the literature through mid-1968. No simple, universally accepted definition of thbe word "alkaloid" exists. Traditionally these compounds have been considered as nitrogenous bases (some are not basic at all) found in plants (some are found in animals), of complex chemical structure (some are quite simple), usually (but certainly not always) producing a marked physiological response in animal systems. Thus they are often associated with the toxicity or the medicinal usefulness of the plants or animals from which they are obtained. Following the isolation of morphine from opium in the early 19th Century, the chemical nature of many of the alkaloids was established and several of them, either as pure compounds or as somewhat standardized mixtures, replaced the plants and extracts from which they were derived and found their places in medicine as useful drugs. About the time of World War I, interest in these substances waned in favor of synthetic medicinals, which a growing chemical industry seemed able to produce at will. Nonetheless, research on these interesting plant substances continued and, in part because natural materials served as models for new and possibly improved synthetic drugs, many novel alkaloids were isolated and charactertized. This is particularly true for the past decade, the "post-reserpine era,"