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The mechanisms of amino acids synthesis by high temperature shock-waves.

The mechanisms of amino acids synthesis behind high temperature shock-waves were elucidated and distinction was made between the steps occurring in the gas phase and those occurring in solution. In the presence of water vapor, aldehydes and HCN are formed separately in regions of different temperatures along the reacting gas. The aldehydes and ammonia condense to aldimines which add HCN to form alpha-amino nitriles, all in the gas phase. The hydrolysis to amino acids takes place in solution. In the absence of water vapor, aldimines and HCN are formed in the gas phase but condense to alpha-amino nitriles only in solution. A fair amount of oxygen only lowers the production of amino acids, which consequently could be still produced in the presence of oxygen in the Earth's primitive atmoshere. The waterless mechanism can operate in the Jovian atmosphere and supply it with ample amounts of amino acids, especially aspartic.

Amino Acids

[Changes in the urinary excretion of gamma-glutamyltranspeptidase, leucine aminopeptidas and alkaline phosphatase in the combined action of ethylene glycol and high temperature].

Gamma-glutamyl transpeptidase (gamma--GTP), leucine aminopeptidase (LAP) and alkaline phosphatase (AP) excretion in rats is followed in dynamics (2, 8, 15, 30 and 90 days) upon isolated and combined treatment with ethylene glycol (EG) at dose 1/8 LD50 and temperature of the environment 35 degrees C. Under the effect of high temperature an increase in the excretion of enzymes in the early observation terms is noted. The independent application of the noxa causes a reduction in gamma--GTR and LAP excretion, and an increase in AP. The temperature factor attenuates the toxic effect of EG relative to the enzymes under study at the end of the observation period. Changes in gamma--GTP excretion are considered as the earliest and most sensitive sign of tubular lesions.

Alkaline Phosphatase

[Changes in Plasmodium berghei berghei in mice maintained at high temperatures].

The study of the evolution of Plasmodium berghei berghei is made in mice kept in a high temperature (35 degrees C) throughout the experiment. Some of these mouse parasites (less than 30%) show a gigantic atypical morphology. In the parasite growing in animals kept at 35 degrees C, the amount of DNA is higher than DNA rate of the parasites growing in control mice (20-22 degrees C). There is no evidence of any relation between the increase of DNA amount and the morphological modification of these parasites.

Animals

Mutant of Escherichia coli that instantaneously loses the ability to adsorb lambda bacteriophage upon exposure to high temperature.

lad (lambda adsorption), an Escherichia coli mutant that loses the ability to adsorb lambda phage immediately after a shift to high temperature (e.g., 42 C), was isolated. This property for phage adsorption is irreversible and has been observed with phage lambda and 21 but not with phages 434, phi 170, and phi 80. A crude receptor preparation, extracted from lad cells will cholate-ethylenediaminetetraacetic acid by the procedure of Randall-Hazelbauer and Schwartz (1973), inactivated the phage lambda only at low temperature.

Adsorption

[Influence of high temperature on the enzyme activity of the small intestine in thyroidectomized rats].

It was revealed in acute experiments that exposure to high temperature changed the invertase, dipeptidase, lipolytic and alkaline phosphatase activity of the small intestinal mucosa in rats. The direction of these changes and their degree differed in the thyroidectomized and sham-operated animals. It is suggested that the thyroid hormones took part in the reaction of the fermentative systems of the small intestine to the action of the thermal factor.

Alkaline Phosphatase

Effect of high-temperature stress on the growth and seed characteristics of barley and cotton.

The existence of a sensitivity gradient to a uniform high-temperature stress applied at stages during seed maturation can be demonstrated in barley. The germination of freshly harvested seed is depressed following heat stress at 7--10 days after awn emergence, but is enhanced by the same stress applied 3 weeks after awn emergence. The depression is attributed to reduced viability associated with thermal injury. The stimulation following stress at more mature stages of seed development is related to a thinner seed coat, increased permeability as evidenced by faster imbibition rate, and decreased content of water-soluble inhibitors in the seed. These effects of environmental stress during seed maturation aid in explaining differences noted in the germinability at harvest of seed produced in successive years or produced in the same year at different locations. Seed of American Cotton, var. AC 134, was stressed at 50 degrees, 60 degrees, 70 degrees, 80 degrees, and 90 degrees C for 24 or 48 h before seeding. Stresses at 50 degrees to 70 degrees C increased seedling emergence and subsequent performance of the cotton plants, but higher temperatures caused thermal injury or killed the seed.

Edible Grain

Experimental evidence for high-temperature organic fractional superconduction in cholates.

Experimental data are presented indicating that six organic compounds (homologous cholates) possess properties associated with high-temperature superconductivity. From magnetic and electrical measurements it is deduced that behavior resembling superconductivity occurs below characteristic transition temperatures in small domains included in the insulating bulk of the sample material, which is therefore designated a fractional o Type III superconductor. The six cholates exhibit this superconductivity below transition temperatures ranging from approximately 7.5 degrees K for sodium dioxycholate to 277 degrees K for sodium cholanate. It has been further established that the diamagnetic shifts with temperature cannot be attributed to ferrielectric, ferroelectric, or capacitive effects. Below the transition temperatures the cholates behave like perfect diamagnets, susceptible to forceful repulsion by a moderate magnetic field. Observed in a sensitive susceptometer, magnetic flux trapped in the material gave rise to a 3% remnant magnetic moment. Studied in particular detail were sodium cholate, sodium deoxycholate, and lithocholic acid, which showed transition temperatures of 30 degrees K, 60 degrees K, and 130 degrees K respectively. The hydrophobic property of the closed four-ring structure (R-group) common to the cholates, along with the hydrophilic property of the carboxylate group (S-group), are responsible for domain formation. Because of those properties, clustering of the S-groups occurs when traces of water are introduced into the material. When followed by slow desiccation, the clusters form the micelles constituting the superconducting domains.

Cholic Acids

Comparative genomic analysis of a novel heat-tolerant and euryhaline strain of unicellular marine cyanobacterium Cyanobacterium sp. DS4 from a high-temperature lagoon.

BACKGROUND: Cyanobacteria have diversified through their long evolutionary history and occupy a wide range of environments on Earth. To advance our understanding of their adaptation mechanisms in extreme environments, we performed stress tolerance characterizations, whole genome sequencing, and comparative genomic analyses of a novel heat-tolerant and euryhaline strain of the unicellular cyanobacterium Cyanobacterium sp. Dongsha4 (DS4). This strain was isolated from a lagoon on Dongsha Island in the South China Sea, a habitat with fluctuations in temperature, salinity, light intensity, and nutrient supply. RESULTS: DS4 cells can tolerate long-term high-temperature up to 50 ℃ and salinity from 0 to 6.6%, which is similar to the results previously obtained for Cyanobacterium aponinum. In contrast, most mesophilic cyanobacteria cannot survive under these extreme conditions. Based on the 16S rRNA gene phylogeny, DS4 is most closely related to Cyanobacterium sp. NBRC102756 isolated from Iwojima Island, Japan, and Cyanobacterium sp. MCCB114 isolated from Vypeen Island, India. For comparison with strains that have genomic information available, DS4 is most similar to Cyanobacterium aponinum strain PCC10605 (PCC10605), sharing 81.7% of the genomic segments and 92.9% average nucleotide identity (ANI). Gene content comparisons identified multiple distinct features of DS4. Unlike related strains, DS4 possesses the genes necessary for nitrogen fixation. Other notable genes include those involved in photosynthesis, central metabolisms, cyanobacterial starch metabolisms, stress tolerances, and biosynthesis of novel secondary metabolites. CONCLUSIONS: These findings promote our understanding of the physiology, ecology, evolution, and stress tolerance mechanisms of cyanobacteria. The information is valuable for future functional studies and biotechnology applications of heat-tolerant and euryhaline marine cyanobacteria.

Cyanobacteria

Efficiency and loading characteristics of EPA's high-temperature quartz fiber filter media.

It was experimentally demonstrated that Gelman Type A and "Microquartz" filters are efficient collectors of nonvolatile particles at high temperatures. Submicron particles penetrated more than large particles, and most at the highest filtration velocity tested of 51 cm/sec. In all tests, however, aerosol penetration was never more than about 0.10%. Nonvolatile particles penetrated less with increasing temperature filter loading. Particles with vaporization points below the sampling temperature, including H2SO4, can vaporize, pass through the glass fiber filters, and then recondense when cooled below their dew points. Therefore, the definition of "particulate matter" must be based upon a prescribed temperature. Hot stack gases, sampled at different filter temperatures, should not necessarily be comparable. Particulate emission standards must involve a suitable reference temperature to allow proper enforcement. Filtration efficiencies calculated by theoretical equations change dramatically with small changes in assumed average filter fiber diameter and/or particle size (or size distribution) used in the calculations. Pinholes not visible to the naked eye do not appear to effect penetration of glass fiber filters enough to significantly alter stack sampling results. Effect of temperature on filtration of non-volatile particles simply resulted in an increasing collection of submicron particles with increasing temperature. The main problems encountered at elevated temperatures were vaporization of volatile particles and mechanical leakage of the filter holder.

Environmental Health

[Effect of freezing, high temperatures and drying on the eggs and larvae of Nematodirus spathiger Railliet, 1896].

A series of laboratory experiments were carried out to test the effect of freezing (--8 to --10 degrees C), high temperatures (15 to 20 degrees C, 26--28 degrees C, 36--37 degrees C, and 58--60 degrees C) on the eggs and larvae of N. spathiger in water, in a dry state, and in the faces. It was found under freezing the eggs retained their viability in water up to 260 days (5.4%), in a dry state up to 330 days (2.8%), and in the feces up to 373 days (5.3%). Embryonated eggs at --8 to --10 degrees C retained their viability up to 440 days. Infective larvae under freezing remained viable in water up to 150 days (4.6%), in a dry state up to 195 days (3.3%), and in the fecal mass up to 230 days (5.2%). Live larvae were detected in the fecal mass on the 450th day (4.6%) when kept at room temperature, on the 395th day (3.5%) at 26--28 degrees C, on the 186th day (5.5%) at 36--37 degrees C, and at the 180th minute (0.8%) at 58--60 degrees C. Frequent wetting and drying of larvae did not produce any unfavourable effect on their viability. A bioassay revealed that infective larvae frozen at --8 to --10 degrees C in the course of 150 days as well as dried at 15--20 degrees C for 166 days remained intact.

Animals

Selective breakage of DNA alongside 5-bromodeoxyuridine nucleotide residues by high temperature hydrolysis.

The substitution of thymine mucleotides (pT) in oligodeoxynucleotides by bromouracil nucleotides (pBU) changes the properties of the oligonucleotides in two ways: (1) It alters their mobility during DEAE-Cellulose homochromatography1. (2) It substantially enhances their sensitivity to high temperature hydrolysis under mildly alkaline conditions (pH 8.9). The resultant breaks occur adjacent to pBU residues and leave terminal phosphates on the breakage products. With more extreme conditions some loss of terminal phosphates can occur. Heating at 100 degrees for 16 hr at pH 8.9 produces cleavage at about half of the pBU residues with minimal loss of terminal phosphates. The properties described here may explain the thermal sensitivity of bacteria grown in 5BU2 and may have a use in DNA sequencing technology.

Base Sequence

[Aminolysis and racemization of activated esters with the use of high temperatures (author's transl)].

The reactivities in aminolysis of the benzyl, phenyl, p-nitrophenyl and pentachlorophenyl esters of benzyloxycarbonylphenylalanine were ascertained at different temperatures up to 90 degrees C and the occurrence of racemization investigated. It turned out that the protective function of the benzyloxycarbonyl group in relation to the racemization was conserved, even at the high temperatures used in the peptide synthesis.

Carboxylic Acids

[Effect of high temperature on the direct cortical response].

Acute experiments were conducted on anesthetized cats placed in a thermochamber at a temperature of 45 degrees C. The direct cortical response in suprasylvian convolution of the cortex during hyperthermia and after the restoration of the thermal homeostasis was studied. It was revealed that hyperthermia caused primary inhibition at a temperature of 40 degrees C and above it, and even complete disappearance of the slow negative potential; above 43 degrees C there was found a gradual depression of the dendrite potential. Restoration of body normothermia following high hyperthermia was accompanied by an insignificant tendency to normalization of the slow negative potential parameters. Analysis of the dendrite potential changes on coupled stimuli testified to the fact that high temperature had a preponderant influence on the presynaptic elements of the cortical axodendrite synapses. On the basis of differential action of heat on the component composition of the direct cortical response a conclusion was drawn on the differences in the sensitivity of functionally different cells of the cortex during hyperthermia.

Animals

Cytochemistry of human catalase. The demonstration of hepatic and renal peroxisomes by a high temperature procedure.

The cytochemical demonstration of marker enzymes for subcellular organelles permits light microscopic analysis of their structure and function in normal and diseased tissues. Currently available staining procedures for the peroxidatic activity of catalase in peroxisomes of plant and animal cells yield weak and inconsistent light microscopic staining when applied to human tissues. We have developed a simple and sensitive high temperature procedure that clearly and reproducibly stains these abundant, but poorly understood, organelles in biopsy specimens of human liver and kidney. This method utilizes formaldehyde fixation, a modified diaminobenzidine (DAB) medium, incubation at 45 degrees C and postosmication for both light and electron microscopy.

Catalase

[Dynamics of transcallosal potentials following local exposure of the cerebral cortex to high temperature].

Experiments were conducted on cats, anesthetized with nembutal. The influence of local heating of the sensomotor cortex on the transcallosum response was examined. It was revealed that heating for short and long periods of limited regions of the cortex of both hemispheres induced a primary depression of the negative component of the transcallosum response at 44 degrees C and above it. The depression was replaced by an irreversible block of both response phases at 47--49 degrees C. It was concluded that the direct inhibitory influence of high temperatures on the cortical neurons was expressed only within the range of extreme temperature incompatible with vital activity of the whole organism. Experiments with the thermal block of the hemisphere region could testify to the fact that the transcallosum responses occurred mainly as a result of the direct irritation of the callosum fibers by stimulating electrodes and entirely reflected the post-synaptic potentials.

Animals

[Effect of overheating on spermatogenesis in mice and the value of heat training in adapting sex cells to the effects of high temperatures].

A single, 10-minute, stay of albino mature mice in a thermochamber at a temperature of 43 degrees C and a relative humidity of 65% caused destruction of the spermatogenic epithelium expressed in degeneration and desquamation of the sexual cells in 55% of the seminiferous tubules. Preliminary 10-day thermal training caused only an intensification of the physiological degeneration of the spermatogenic cells in 16% of the seminiferous tubules; this could point to the adaptation of the sex cells to the action of the high temperature.

Adaptation, Physiological