scholarly journals Temperature characteristics of peptidase in chironomid larvae, potential fish prey, at various pH values

2018 ◽  
Vol 26 (3) ◽  
pp. 201-205
Author(s):  
V. V. Kuz’mina ◽  
E. Y. Chornaya ◽  
E. G. Skvortsova ◽  
E. A. Kulivatskaya ◽  
V. A. Sheptitskiy
Keyword(s):  
Temperature Dependence ◽  
High Temperatures ◽  
Juvenile Fish ◽  
The Body ◽  
Ecological Groups ◽  
Fish Prey ◽  
Chironomid Larvae ◽  
Temperature Characteristics ◽  
Different Temperatures ◽  
Hydrolysis Of

The temperature dependence of casein- and hemoglobinlytic peptidases functioning in the whole organism of chironomid larvae Chironomus plumosus, food objects of adult benthophages and juvenile fish of various ecological groups, was studied within the temperature range of 0–70 ºС at different рН values (3.0, 5.0 and 7.4). The method of mixed samples was used to determine the activity and characteristics of enzymes. Homogenates of previously crushed and carefully mixed dozens of larvae were used as enzymatically active preparations. Activity of peptidases was assayed by the increase in tyrosine concentration using the Folin-Ciocalteu reagent. It is shown that the activity of peptidases that function in the tissues of chironomid larvae depends to a considerable extent on temperature and рН, but the pH has a smaller effect on the activity and the temperature dependence of casein- and hemoglobin-lytic peptidases than temperature. The temperature optimum of the studied peptidases of chironomid larvae corresponds to 40 ºС. The Q10 values in the zone of vital temperatures are slightly changed. They are, as a rule, increased in the zone of 30–40 ºС, and are sharply decreased in the zone of high temperatures. The values of activation energy of the process of hydrolysis of casein and hemoglobin in the zone of low and high temperatures are different. The Еact values of the process of hydrolysis of casein and hemoglobin at a temperature not exceeding 20 ºС are usually below those in the zone of higher temperatures (except for hemoglobin-lytic peptidases at pH 5.0). The data obtained indicate a significant effect of pH not only on the activity, but also on the temperature characteristics of peptidases that function in the body of chironomid larvae. Differences in the characteristics of casein- and hemoglobin-lytic peptidases in chironomid larvae at different temperatures and pH can influence the digestion in benthophages and fry of all fish species.

scholarly journals NOTE ON THE VARIATION WITH TEMPERATURE OF THE RELATIVE RATES OF HYDROLYSIS OF GLUCOSIDES

1930 ◽  
Vol 13 (3) ◽  
pp. 317-321 ◽  
Author(s):  
Emyr Alun Moelwyn-Hughes
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Different Temperatures ◽  
Hydrolysis Of ◽  
Special Case

Attention is drawn to the necessity of taking the values of the critical increments into account when the velocity constants for reactions of any pair of glucosides are compared. The ratio of the velocity coefficients for the hydrolysis of any two glucosides, determined at the same temperature, varies with temperature except in the special case when both hydrolyses have the same critical increment. Different values given by various investigators for the same ratio are shown to be due to the fact that comparative experiments have been carried out at different temperatures with two glucosides possessing different critical increments of hydrolysis. In the light of these considerations it becomes necessary to revise certain deductions which have been drawn from the comparison of rates of hydrolysis of glucosides by acids (at fairly high temperatures) with the rates of hydrolysis of glucosides by enzymes (at relatively low temperatures).

Influence of Contact Metallisation on the High Temperature Characteristics of High-κ Dielectrics

2013 ◽  
Vol 740-742 ◽  
pp. 837-840
Author(s):  
Benjamin J.D. Furnival ◽  
Sandip K. Roy ◽  
Nicolas G. Wright ◽  
Alton B. Horsfall
Keyword(s):  
High Temperature ◽  
Temperature Dependence ◽  
High Temperatures ◽  
Epitaxial Layer ◽  
Electrical Characteristics ◽  
Temperature Characteristics ◽  
High K ◽  
High K Dielectric ◽  
Increasing Temperature ◽  
Mis Capacitors

In this work SiC-based MIS capacitors have been fabricated with different contact/high-k dielectric combinations and the temperature dependence of the characteristics have been examined in an N2ambient at temperatures between 323K and 673K. The structures utilise either a Pt or Pd catalytic gate contact and a TiO2or HfO2high-k dielectric, all of which are grown on a thin SiO2layer, thermally grown on the Si face of a 4H SiC epitaxial layer. The MIS capacitors have been studied in an N2 ambient between 323K and 673K and observations show that VFBreduces with increasing temperature. The majority of this variation is caused a reduction in the Ditinfluencing the structures electrical characteristics, due to a shift in the semiconductors bulk potential, which is due to the lower VTHof SiC-based MOSFETs at high temperatures.

scholarly journals Monogeneans of fish of the Mingechevir Reservoir of the Kura River basin

2019 ◽  
Keyword(s):  
River Basin ◽  
Juvenile Fish ◽  
Rutilus Rutilus ◽  
The Body ◽  
Small Fish ◽  
Ecological Groups ◽  
Roach Rutilus Rutilus ◽  
Spined Loach ◽  
Silurus Glanis ◽  
Faunistic Complex

In 2010–2013, a study on fish of the Mingechevir Reservoir of the Kura River basin, for infestation with parasites belonging to the Monogenea class was conducted. 297 specimens of fish were subjected to parasitological dissections. These fish belong to the following 23 species: roach – Rutilus rutilus caspius, Caucasian chub – Leuciscus cephalus orientalis, asp – Aspius aspius taeniatus, tench – Tinca tinca, Kura nase – Chondrostoma cyri, Kura khramulya – Capoeta capoeta, chanari-barbel – Luciobarbus capito, goldfish – Carassius auratus gibelio, carp – Cyprinus carpio, Kura beardie – Barbatula brandti, Transcaucasica spined loach – Cobitis taenia satunini, catfish – Silurus glanis, mosquito fish – Gambusia affinis, pike – Sander lucioperca, big headed goby – Neogobius kessleri gorlap, monkey goby – N. fluviatilis pallasi. As a result of the research, 34 species of monogeneans belonging to 3 orders of 4 families and 5 genera were identified. The overwhelming majority (32 species) of monogeneans found are parasitic on the gill petals of fish, from two to six species are also found on the surface of the body and fins, in the nasal cavity of fish. Of the found monogeneans, 24 species (70.6%) are specific for one species or one genus of fish. It has been established that monogeneans parasitizing on several hosts infect the main of them more than others fish, and the intensity of invasion of fish with large sizes was higher than that of relatively small fish. By their origin, 23 species or 67.7% of all species belong to the boreal lowland faunistic complex. According to the ecological groups of this complex, they are distributed as follows: in the Ponto-Caspian group – 17 species, in the Palaearctic and amphiboreal groups – 3 species each. The Middle East faunistic complex is represented by six, the Indian lowland complex is represented by three, and the Ponto-Caspian marine complex by two species. Among the monogeneans of fish of the Mingechevir Reservoir, two species, Dactylogyrus extensus and D. vastator destroy gill petals of their hosts and cause their diseases. They are the cause of the mass death of juvenile fish.

Salt effect in hydrolysis of 3-acyl-1,3-diphenyltriazenes

1981 ◽  
Vol 46 (12) ◽  
pp. 3104-3109 ◽  
Author(s):  
Miroslav Ludwig ◽  
Oldřich Pytela ◽  
Miroslav Večeřa
Keyword(s):  
Sodium Chloride ◽  
Temperature Dependence ◽  
Potassium Chloride ◽  
Rate Constants ◽  
Zinc Sulphate ◽  
Salt Effect ◽  
Sodium Sulphate ◽  
Potassium Sulphate ◽  
Lithium Sulphate ◽  
Hydrolysis Of

Rate constants of non-catalyzed hydrolysis of 3-acetyl-1,3-diphenyltriazene (I) and 3-(N-methylcarbamoyl)-1,3-diphenyltriazene (II) have been measured in the presence of salts (ammonium chloride, potassium chloride, lithium chloride, sodium chloride and bromide, ammonium sulphate, potassium sulphate, lithium sulphate, sodium sulphate and zinc sulphate) within broad concentration ranges. Temperature dependence of the hydrolysis of the substrates studied has been measured in the presence of lithium sulphate within temperature range 20° to 55 °C. The results obtained have been interpreted by mechanisms of hydrolysis of the studied substances.

scholarly journals The Respiration of some Planktonic copepods II. The Effect Of Temperature

1953 ◽  
Vol 31 (3) ◽  
pp. 447-460 ◽  
Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont
Keyword(s):  
Respiratory Rate ◽  
The Body ◽  
The Other ◽  
Effect Of Temperature ◽  
Acartia Clausi ◽  
Temora Longicornis ◽  
Different Temperatures ◽  
Planktonic Copepods ◽  
The Difference ◽  
The Relationship

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.

A kinetic standard for precise calibration of spectrophotometer cell temperature.

1981 ◽  
Vol 27 (5) ◽  
pp. 753-755 ◽  
Author(s):  
P A Adams ◽  
M C Berman
Keyword(s):  
Temperature Dependence ◽  
Rate Constants ◽  
Cell Temperature ◽  
First Order ◽  
Order Rate ◽  
Acid Catalyzed ◽  
Pseudo First Order ◽  
Hydrolysis Of

Abstract We describe a simple, highly reproducible kinetic technique for precisely measuring temperature in spectrophotometric systems having reaction cells that are inaccessible to conventional temperature probes. The method is based on the temperature dependence of pseudo-first-order rate constants for the acid-catalyzed hydrolysis of N-o-tolyl-D-glucosylamine. Temperatures of reaction cuvette contents are measured with a precision of +/- 0.05 degrees C (1 SD).

scholarly journals The effect of drying temperature on the properties of gelatin from carps (Cyprinus carpio) skin

2019 ◽  
Vol 37 (No. 4) ◽  
pp. 246-251 ◽  
Author(s):  
Joanna Tkaczewska ◽  
Maciej Wielgosz ◽  
Piotr Kulawik ◽  
Marzena Zajac
Keyword(s):  
Cyprinus Carpio ◽  
Freeze Drying ◽  
Treatment Method ◽  
Thermal Hydrolysis ◽  
Gel Properties ◽  
Drying Temperature ◽  
Freeze Dried ◽  
Different Temperatures ◽  
Pre Treatment ◽  
Hydrolysis Of

The influence of drying temperature on the characteristics and gel properties of gelatine from Cyprinus carpio L. skin was studied. Gelatine was extracted from the carp skin using NaOH and ethanol pre-treatment method, extracted in water in 45°C and then dried in 4 different temperatures: 50, 70, 80°C and freeze-dried. The  electrophoresis and functional properties of gelatines were investigated. Freeze drying allowed to obtain a high gelling force, and all other methods did not give satisfactory results. The proteins in gelatines dried at higher temperatures separated by electrophoresis gave severely blurred bands. It may be explained by thermal hydrolysis of collagen fibrils. Freeze drying is the only effective method for drying this product, which can be used in industry.

scholarly journals Influence of Fabric Weave on Thermal Radiation Resistance and Water Vapor Permeability

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 525
Author(s):  
Ana Kiš ◽  
Snježana Brnada ◽  
Stana Kovačević
Keyword(s):  
High Temperatures ◽  
High Performance ◽  
Thermal Protection ◽  
Water Vapor Permeability ◽  
Radiant Heat ◽  
The Body ◽  
Vapor Permeability ◽  
Weave Structure ◽  
Fabric Structures ◽  
The Impact

In this work, aramid fibers were used to develop new, high-performance fabrics for high-temperature protective clothing. The research was based on the impact of the weave structure on fabric resistance to radiant heat. The goals of the research were primarily related to the development of new fabric structures created by the weave structure, which gives better protection of the body against high temperatures in relation to the standard weave structures that are used today. According to the results obtained it can be concluded that the fabric weave significantly affects the fabric structure, which consequently determines the effectiveness of protection against high temperatures. The justification for the use of multi-weft and strucks weave structure, which provides greater thermal protection and satisfactory breathability than commonly used weave structures, was ascertained.

Neutral Solvolysis of Acyl Carbon and the Temperature Dependence of the Kinetic Solvent Isotope Effect

1975 ◽  
Vol 53 (6) ◽  
pp. 869-877 ◽  
Author(s):  
B. Rossall ◽  
R. E. Robertson
Keyword(s):  
Temperature Dependence ◽  
Isotope Effect ◽  
Solvent Isotope Effect ◽  
Acyl Carbon ◽  
Rate Of Hydrolysis ◽  
Solvent Isotope ◽  
Neutral Conditions ◽  
Hydrolysis Of

The temperature dependence of the rate of hydrolysis of benzoic, phthalic, and succinic anhydrides have been determined in H2O and D2O under "neutral" conditions. Corresponding data have been obtained for methyl trifluoroacetate. While both series supposedly react by the same BAc2 mechanism, remarkable differences are made obvious by this investigation. Possible sources of such differences are proposed.

Sign in / Sign up

Export Citation Format

Share Document