scholarly journals The structure of haem in pyridine/water mixtures and its implication in studies of haem catabolism

1976 ◽  
Vol 153 (2) ◽  
pp. 479-483 ◽  
Author(s):  
S B Brown ◽  
R F G J King
Keyword(s):  
Sharp Decrease ◽  
Aggregation Process ◽  
Hydrophobic Nature ◽  
Oxidation Degradation ◽  
Pyridine Concentration

1. A study of haem spectra in pyridine/water mixtures at low pyridine concentrations revealed changes in haemochrome structure consistent with an aggregation process. No corresponding change in the structure of the haemichrome species was observed. 2. This aggregation has been correlated with a previously observed sharp decrease in the rate of coupled oxidation (degradation) of haem as pyridine concentration is decreased. The decrease appears to be due primarily to haem aggregation and not to changes in the hydrophobic nature of the solvent. The effect of ethanol and butanone addition was examined and supports this conclusion. 3. Evidence is presented that coupled oxidation occurs via the iron (II) species (haemochrome).

A Sensitive On-Grid Immunoelectron Microscopic Procedure for Diagnosis of Rotavirus Infection

1980 ◽  
Vol 38 ◽  
pp. 506-507
Author(s):  
M. F. Miller ◽  
A. R. Rubenstein
Keyword(s):  
Electron Microscopy ◽  
Specific Antibody ◽  
Immune Complexes ◽  
Acute Gastroenteritis ◽  
Plant Viruses ◽  
Aggregation Process ◽  
Microscopic Technique ◽  
Fecal Material ◽  
Present Communication ◽  
Number Of Particles

Studies of rotavirus particles in humans, monkeys and various non-primates with acute gastroenteritis have involved detection of virus in fecal material by electron microscopy. The EM techniques most commonly employed have been the conventional negative staining (Fig. 1) and immune aggregation (Fig. 2) procedures. Both methods are somewhat insensitive and can most reliably be applied to samples containing large quantities of virus either naturaLly or as a result of concentration by ultracentrifugation. The formation of immune complexes by specific antibody in the immune aggregation procedures confirms the rotavirus diagnosis, but the number of particles per given microscope field is effectively reduced by the aggregation process. In the present communication, we describe use of an on-grid immunoelectron microscopic technique in which rotavirus particles are mounted onto microscope grids that were pre-coated with specific antibody. The technique is a modification of a method originalLy introduced by Derrick (1) for studies of plant viruses.

Verbal Punishment of Disfluencies in Normal Speakers

1965 ◽  
Vol 8 (3) ◽  
pp. 245-251 ◽  
Author(s):  
Gerald M. Siegel ◽  
Richard R. Martin
Keyword(s):  
Sharp Decrease ◽  
Random Presentation ◽  
Random Schedule

Forty normal speakers were divided into two groups to study the effects of two types of verbal punishment of disfluencies. The two conditions, Random and Contingent, were divided into three segments each. Punishment was not delivered in Segments 1 or 3. Segment 2 presented Random subjects with the tape recorded word “wrong” on a predetermined random schedule. Contingent subjects were delivered the word “wrong” after each disfluency. Random presentation of “wrong” did not significantly affect rate of disfluencies. Contingent presentation resulted in a sharp decrease in disfluencies during Segment 2, and an increase in disfluencies during Segment 3.

Influence of Polymer Charge, Temperature, and Surfactants on Surface Sizing of Liner and Greaseproof Paper With Hydrophobically Modified Starch

TAPPI Journal ◽  
2009 ◽  
Vol 8 (2) ◽  
pp. 33-38 ◽  
Author(s):  
ANNA JONHED ◽  
LARS JÄRNSTRÖM
Keyword(s):  
Phase Separation ◽  
Contact Angles ◽  
Low Ph ◽  
Hydrophobically Modified ◽  
Paper Sizing ◽  
Surface Sizing ◽  
Separation Temperature ◽  
Hydrophobic Nature ◽  
Sizing Agents ◽  
Charge Temperature

The aim of this study was to investigate the properties of hydrophobically modified (HM) quaterna-ry ammonium starch ethers for paper sizing. These starches possess temperature-responsive properties; that is, gelation or phase separation occurs at a certain temperature upon cooling. This insolubility of the HM starches in water at room temperature improved their performance as sizing agents. The contact angles for water on sized liner were substantially larger than on unsized liner. When the application temperature was well above the critical phase-separation temperature, larger contact angles were obtained for liner independently of pH compared with those at the lower application temperature. Cobb60 values for liner decreased upon surface sizing, with a low pH and high application temperature giving lower water penetration. Contact angles on greaseproof paper decreased upon sur-face sizing as compared to unsized greaseproof paper, independently of pH and temperature. Greaseproof paper showed no great difference between unsized substrates and substrates sized with HM starch at different pH. This is probably due to the already hydrophobic nature of greaseproof paper. However, the Cobb60 values increased at low pH and low application temperature. Surfactants were added to investigate how they affect the sized surface. Addition of surfactant reduces the contact angles, in spite of indications of complex formation.

Enzymic Correlates of Development, Secretory Function and Regression of Follicles and Corpora Lutea in the Bovine Ovary. PART II: Formation, Development and Involution of Corpora Lutea

1968 ◽  
Vol 59 (2_Suppl) ◽  
pp. S35-S51 ◽  
Author(s):  
B. L. Lobel ◽  
E. Levy
Keyword(s):  
Corpus Luteum ◽  
Vascular System ◽  
Hydrolytic Enzymes ◽  
Sharp Decrease ◽  
Cellular Growth ◽  
Corpora Lutea ◽  
Cell Nuclei ◽  
Steroid Synthesis ◽  
Luteal Cells ◽  
Vascular Walls

ABSTRACT Activities of various hydrolases and dehydrogenases were studied during the formation, development and involution of cyclic corpora lutea and in the corpora lutea of early pregnancy. At 24 hours postovulation the luteal cells, whether of granulosal or thecal origin, contained demonstrable levels of Δ5-3β-hydroxysteroid dehydrogenase and the NADP and NADPH2 diaphorases. During the period of proliferation and cellular growth, enzymic activities in the luteal cells were moderate at first, and then increased. In the mature corpus luteum, activities of the dehydrogenases occurred in all luteal cells but were most intense in the large polymorphic luteal cells. Activities of hydrolytic enzymes, low in the immediate postovulatory period, increased with the development of the vascular system. Enzymic characteristics of corpora lutea of gestation were similar to those of cyclic corpora, except for phosphorylase activity which was observed in luteal cells in gestational corpora, but confined to the vascular walls in cyclic corpora. No increase in activities of 17β- and 20β-hydroxysteroid dehydrogenases (above those seen in pre-ovulatory follicles) were observed after incubation of sections of either mature cyclic or gestational corpora. Involution of cyclic corpora lutea began with degenerative changes in the blood vessels: pyknosis of the endothelial cell nuclei and a sudden decline in activities of hydrolytic enzymes in the vascular walls. Subsequently, the luteal cells showed a sharp decrease in activities of the dehydrogenases as well as other signs of regressive change. The cytochemical findings are discussed in relation to biochemical observations on steroid synthesis by the bovine corpus luteum.

Effects of progesterone induced postmaturity on CBG and pituitary-adrenal activities in the rat foetus

1986 ◽  
Vol 112 (3) ◽  
pp. 396-403 ◽  
Author(s):  
Jean Paul Dupouy ◽  
Alain Chatelain
Keyword(s):  
Binding Capacity ◽  
Sharp Decrease ◽  
Plasma Corticosterone ◽  
Corticosterone Concentration ◽  
Rat Pups ◽  
Body Weights ◽  
Normal Rat ◽  
Severe Jaundice ◽  
High Level ◽  
Subsequent Rise

Abstract. CBG and pituitary-adrenal activities were investigated in intact rat foetuses, in newborns spontaneously delivered by vaginal way and in postmature foetuses from mothers with delayed parturition caused by daily progesterone injection from day 20 of gestation. The postmature foetuses had lower body weights and higher adrenal weights on day 22, 23 and 24 of gestation than newborns of the same conceptional age. The corticosterone binding capacity of the plasma as well as the binding capacity of CBG for corticosterone decreased in intact foetuses for the last 3 days of gestation and stayed very low in pups from day 0 to day 8 postpartum. These parameters decreased more slowly in postmature foetuses; however, the differences between the latter and intact foetuses or newborns were not statistically significant. Similar evolution occurred in intact pregnant and suckling females as well as in females with prolonged gestation. The fall in CBG activity in normal rat pups and the subsequent rise in free steroids could explain a sharp decrease in plasma ACTH levels as well as the drop in adrenal and plasma corticosterone concentration. In foetuses with prolonged gestation, the same phenomenon did not occur. Stress conditions produced by maintaining growing foetuses in utero and the development of severe jaundice maintained high ACTH levels. In contrast, the fall in adrenal and plasma corticosterone concentrations in spite of the high level of circulating ACTH could be mainly due to the progesterone inhibition of the steroidogenic activity of the foetal adrenals.

Photosynthetic activity of spring wheat depending on the conditions of water supply

2020 ◽  
Author(s):  
I.I. Seregina ◽  
◽  
I.G. Makarskaya
Keyword(s):  
Water Supply ◽  
Spring Wheat ◽  
Sodium Selenite ◽  
Photosynthetic Activity ◽  
Wheat Variety ◽  
Sharp Decrease ◽  
Soil Culture ◽  
Growing Conditions ◽  
Spring Wheat Variety ◽  
Excessive Water

Abstract:In model experiments in soil culture, the effect of different methods of treatment with sodium selenite on the photosynthetic activity of spring wheat variety Zlata was studied under extreme growing conditions. Under drought conditions, the inhibition of the growth of the photosynthetic surface of spring wheat plants was revealed. Under conditions of excessive water supply, a sharp decrease in the area of the assimilating surface of wheat plants was observed. The positive effect of sodium selenite solution on the photosynthetic activity of spring wheat plants was established with insufficient and excessive water supply to wheat plants.

Communicative Strategies and Tactics of Debate as a Learning Tool

2020 ◽  
Vol 81 (2) ◽  
pp. 21-26
Author(s):  
Z. I. Kurtseva
Keyword(s):  
Questionnaire Survey ◽  
Sharp Decrease ◽  
Russian Language ◽  
Point Of View ◽  
Primary Data ◽  
Federal State ◽  
School Students ◽  
Communicative Strategies ◽  
Psychology Pedagogy ◽  
State Educational

This article discusses an urgent educational problem, i.e. a sharp decrease in the level of students’ spoken language and, in particular, the lack of willingness and ability among school students to engage in a constructive dialogue when participating in debates. It is no accident that modern federal state educational standards pay special attention to the formation of students’ communicative competence at all levels of education. The aim of this article was to investigate the current situation in the field in order to obtain primary data showing at which educational levels the techniques of debate and discussion are used; to analyse the verbal behaviour of participants implementing various communicative strategies and tactics during debates. The following research methods were used: an analysis of literature in the field of psychology, pedagogy, communication and methodology; a questionnaire survey and interviews; an analysis of the oral presentations of students; generalization of pedagogical experience. The results of the interviews and questionnaire survey conducted among first-year university show that about 60% of the respondents experience difficulties in constructing argumentative speech. Discussions in schools are held only in high school. Secondary school teachers lack the competencies of organizing and conducting debates in class. The development of communicative skills of defending one’s point of view and conducting informed debates using communicative tactics based on the principles of dialogue and politeness should be taught during teenage years. It is at this age that communicative competencies are most actively formed. Specific examples of including debates in the curriculum of the Russian language (5th grade) for developing primary discussion skills are presented.

POLAR LOW DETECTION USING SOLAB SIOWS ARCTIC PORTAL

2017 ◽  
Author(s):  
Olga Mashtaler ◽  
Olga Mashtaler ◽  
Alexander Myasoedov ◽  
Alexander Myasoedov ◽  
Elizaveta Zabolotskikh ◽  
...  
Keyword(s):  
Model Development ◽  
Sharp Decrease ◽  
Open Water ◽  
The Arctic ◽  
Wind Fields ◽  
Polar Lows ◽  
Statistical Regularities ◽  
Meteorological Observations ◽  
Strong Winds ◽  
Synthetic Aperture Radars

The relevance of the polar lows (PLs) research is justified by their great destructive power and creation of threat to the safety of navigation in the high latitudes and along the Northern Sea Route. The most dangerous effects on maritime activities are strong winds, waves and icing. In addition, the study of the PLs acquires relevance due to the sharp decrease of the sea ice area in the Arctic in recent years and the emergence of areas of open water, suitable for the appearance and development of PLs. However, despite the importance of PLs, they are apparently not sufficiently studied. As there are no meteorological observations in the areas of their appearance, the main source of information about them are satellite observations. By using images on the SOLab SIOWS Arctic Portal from multiple satellites operating in the IR and visible ranges (e.g., MODIS and AVHRR), and using near-water wind fields from high resolution synthetic aperture radars (Sentine-1, ASAR) and low resolution scatterometers (ASCAT), we identify polar lows in various parts of the Arctic, revealing statistical regularities in the appearance of PLs, their distribution and intensity. Collected database of Pls and their characteristics will be used for further PLs forecasting model development.

ROLE OF THE STROMAL CELLULAR COMPONENT IN COMPENSATORY PROCESSES IN DIFFUSE LIVER DAMAGE

2018 ◽  
pp. 32-37 ◽  
Author(s):  
Z. A. Shafigullina ◽  
S. Yu. Medvedeva ◽  
I. G. Danilova
Keyword(s):  
Toxic Hepatitis ◽  
Intraperitoneal Administration ◽  
Sharp Decrease ◽  
Cellular Component ◽  
Ki 67 ◽  
Sinusoidal Cells ◽  
Toxic Damage ◽  
Stromal Component ◽  
Regeneration Processes

The aim of the study was to assess the role of the cellular component of the stroma in liver regeneration after its toxic damage. The experimental model of toxic hepatitis caused by intraperitoneal administration of tetrachloromethane (CCl4) showed that regeneration processes in the liver on the 3rd day are manifested in an increase in binuclear hepatocytes, Ki-67 + cells and hepatocytes dividing by mitosis. The reaction of the stromal component is expressed in an increase in the number of CD45 +, mast and sinusoidal cells (SC). On the 7th day of the development of toxic hepatitis the hepatocyte alteration increases, that is accompanied by a sharp decrease in the mitotic index and the number of Ki-67 + cells. In the stromal component there is a decrease in the number of sinusoidal cells, CD45 + and a significant increase in mast cells with a high secretion granule content.

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