scholarly journals Hepatic cryosurgery in experiment and clinic

2003 ◽  
Vol 2 (3) ◽  
pp. 56-61
Author(s):  
B. I. Alperovich ◽  
A. V. Potapov ◽  
V. N. Salo
Keyword(s):  
Low Temperature ◽  
Hepatic Resection ◽  
Morphological Changes ◽  
Hepatic Tissue ◽  
Experimental Investigations ◽  
Original Design ◽  
Hepatic Diseases ◽  
Electron And Light Microscopy ◽  
Design Characteristics ◽  
Sexually Mature

The aim of the investigation – to study changes in hepatic tissue resulting from the influence of low temperatures (– 195,8 °C) in experiments and clinic. Hepatic tissue investigations in experiment have been carried out using electron and light microscopy. During the surgery instruments of original design have been used – cryoscalpels and cryodestructors. Experiments have been carried out on 45 sexually mature dogs of both sexes. Animals have been separated into 3 groups. On the first group (consisting of 12 animals), in the acute experiment, there have been studied features of cryoscalpel design characteristics. In the second series of experiment (on 22 dogs) there have been made a comparative study of hepatic resection using cryoultrasonic scalpel and simple surgical scalpel by means of the study of hemorrhage quantity. In 11 cases there have been studied hepatic morphological changes affected by cryoeffect. By the effect of low temperature ice crystals are appeared in hepatic tissue intracellularly and outside the cell, they cause mechanical injury and rupture of hepatic tissue. In 45 days connective tissue elements are formed at the place of cryodestruction. The use of cryoultrasonic scalpel in hepatic resection in the experiment decreases the hemorrhage quantity by 1,26 times as compared to the traditional methods. Positive experimental investigations allowed to use the low temperature with success in clinical practice at 253 patients with different localized hepatic diseases with 13 lethal outcomes (5,1%). Thus, the used cryosurgical technique during surgical operations allows to decrease significantly the hemorrhage, to eliminate parenchymatous bleeding and to prevent relapses of disease both at growths and at parasitic hepatic affection.

scholarly journals The association gene’s TNFα G(308) with quantity of TNFα and degree of liver’s fibrosis in patients with chronic hepatitis C

2018 ◽  
Vol 22 (4) ◽  
pp. 682-685
Author(s):  
E.N. Usychenko ◽  
Yu.I. Bazhora ◽  
E.M. Usychenko ◽  
V.A. Gudz
Keyword(s):  
Chronic Hepatitis ◽  
Hepatitis C ◽  
Liver Fibrosis ◽  
Chronic Hepatitis C ◽  
Degrees Of Freedom ◽  
Morphological Changes ◽  
Polymorphic Marker ◽  
Pathological Process ◽  
Hepatic Tissue ◽  
The Individual

The data on the polymorphism of cytokine genes associated with individual reactivity on the effects of hepatitis C virus, predict the rate of progression of liver fibrosis. The purpose of this work is study the association of the polymorphic marker G308A of the TNFα gene with its quantitative content and degree of liver fibrosis in patients with chronic hepatitis C. A total of 100 patients with CSF were examined. The polymorphism of G308A gene’s TNFα was studied by amplification of the corresponding genome zones by PCR. The assessment of the degree of fibrosis was performed using the non-invasive Fibrotest method. The study of the quantity of TNFα cytokine in serum of patients was performed by ELISA. The distribution of genotypes on the investigated polymorphic loci was verified using Pearson's χ2 criterion. The frequencies of alleles and genotypes in the groups were compared using Pearson's χ2 criterion with Yates correction for continuity with the number of degrees of freedom 1. In order to detect the correlation dependencies between the individual parameters, the Spearman correlation coefficient was applied. It was found that a smaller degree of fibrosis was observed in carriers of the GG TNFα genotype, and a greater degree of fibrosis in the carriers of the genotype AA TNFα (moderate feedback between the degree of fibrosis and the genotypes of TNFα). The higher content of TNFα is noted in the carriers of the AA genotype TNFα, the lower content of TNFα - in the carriers of the GG TNFα genotype (moderate feedback between the TNFα genotypes and the TNFα content). It has been established that a higher TNFα content is observed in patients with F1-F0 fibrosis, a lower TNFα content in patients with F2-F3 fibrosis (a strong correlation between the degree of fibrosis and the amount of TNFα cytokine). It is assumed that the production of the cytokine is determined at the genetic level, and the severity of changes in the cytokine profile in chronic hepatitis C affects the course of the pathological process. An increase in the TNFα content in chronic hepatitis C may be a marker for significant morphological changes in the hepatic tissue and high activity of the inflammatory process.

scholarly journals Searching for signatures of life on Mars: an Fe-isotope perspective

2006 ◽  
Vol 361 (1474) ◽  
pp. 1715-1720 ◽  
Author(s):  
M Anand ◽  
S.S Russell ◽  
R.L Blackhurst ◽  
M.M Grady
Keyword(s):  
Low Temperature ◽  
Liquid Water ◽  
Isotope Composition ◽  
Isotopic Fractionation ◽  
Isotope Ratios ◽  
Experimental Investigations ◽  
Form Of Life ◽  
Geological Past ◽  
Martian Meteorites ◽  
Fe Reduction

Recent spacecraft and lander missions to Mars have reinforced previous interpretations that Mars was a wet and warm planet in the geological past. The role of liquid water in shaping many of the surface features on Mars has long been recognized. Since the presence of liquid water is essential for survival of life, conditions on early Mars might have been more favourable for the emergence and evolution of life. Until a sample return mission to Mars, one of the ways of studying the past environmental conditions on Mars is through chemical and isotopic studies of Martian meteorites. Over 35 individual meteorite samples, believed to have originated on Mars, are now available for lab-based studies. Fe is a key element that is present in both primary and secondary minerals in the Martian meteorites. Fe-isotope ratios can be fractionated by low-temperature processes which includes biological activity. Experimental investigations of Fe reduction and oxidation by bacteria have produced large fractionation in Fe-isotope ratios. Hence, it is considered likely that if there is/were any form of life present on Mars then it might be possible to detect its signature by Fe-isotope studies of Martian meteorites. In the present study, we have analysed a number of Martian meteorites for their bulk-Fe-isotope composition. In addition, a set of terrestrial analogue material has also been analysed to compare the results and draw inferences. So far, our studies have not found any measurable Fe-isotopic fractionation in bulk Martian meteorites that can be ascribed to any low-temperature process operative on Mars.

scholarly journals Morphological manifestations of freezing and thawing injury in bacteriophage T4Bo

1976 ◽  
Vol 77 (1) ◽  
pp. 119-127 ◽  
Author(s):  
P. R. M. Steele
Keyword(s):  
Low Temperature ◽  
Morphological Changes ◽  
Plaque Assay ◽  
Electron Microscopic Observation ◽  
Eutectic Phase ◽  
Phase Changes ◽  
Extended Form ◽  
Freezing And Thawing ◽  
Electron Microscopic ◽  
Tail Sheath

SUMMARYElectron microscopic observation of negatively stained preparations of frozen and thawed suspensions of T4Bo phage clearly separated the morphological changes produced by low-temperature salt denaturation from those produced by eutectic phase changes. Salt denaturation caused contraction of tail sheaths. Eutectic phase changes appeared to cause two separate lesions. Firstly the tail sheath was disjointed 18–22 nm. below the collar and the tail core was disjointed at 40–60 nm. below the collar, giving rise to separated heads with a small tail remnant, and separated tails in which the sheath remarkably remained in its extended form. Secondly, tears were seen in the head membranes of particles with collapsed empty heads. In all the experiments the percentage of normal phage particles counted electron-microscopically was close to the percentage of viable phage as determined by plaque assay.

EXPERIMENTAL INVESTIGATION OF QUALITY METRICS FORMATION PROCESS DURING PLASTIC MILLING

2016 ◽  
Vol 2016 (3) ◽  
pp. 129-136 ◽  
Author(s):  
Павел Черданцев ◽  
Pavel Cherdantsev ◽  
Андрей Марков ◽  
Andrey Markov ◽  
Софья Катаева ◽  
...  
Keyword(s):  
Composite Materials ◽  
Tool Wear ◽  
Cutting Speed ◽  
Experimental Investigations ◽  
Geometrical Parameters ◽  
Original Design ◽  
Transverse Fiber ◽  
Fiber Winding ◽  
Estimate Of Parameter ◽  
Cutting Modes

Composite materials are widely used in mechanical engineering, but at edge cutting machining, in particular, during milling these materials a number of peculiarities arise which must be taken into account at the definition of cutting modes and design-geometrical parameters of cutters. Besides, new composite materials machining does not allow using effectively the recommendations developed earlier. In such a way, to solve such a problem it is necessary to carry out experimental investigations on the analysis of the influence of milling mode characteristics and design-geometrical of a tool upon values of roughness of a surface processed and tool wear. As a cutter for investigations there were taken hardmetal endmilling cutters of TC-8 (tungstencobalt) type, the experimental samples – pipes made of composite material with oblique longi-tudinal-transverse fiber winding (OLTFW). As varied parameters were adopted cutting modes: cutting speed V, m/min, feed S, mm/tooth and milling depth t, mm. During the experiments were controlled the following parameters: tool wear Δ, mkm, roughness of the surface Ra, mkm and a depth of a faulty layer h, mkm. To carry out the experiments there was offered an original design of an assembly milling cutter which allows defining in an experimental way optimum geo-metrical parameters of a tools to achieve output milling parameters specified. On the basis of experiments data there are obtained dependences allowing the estimate of parameter modes influence upon the period of cutter duration at the same time a temperature is affected mostly by a milling depth and a feed on a tooth affects the wear of an end flank.

Electrical Conductivities of Low-Temperature KCl-ZrCl4 and CsCl-ZrCl4 Molten Mixtures

2018 ◽  
Vol 73 (3) ◽  
pp. 259-263
Author(s):  
Alexander B. Salyulev ◽  
Alexei M. Potapov
Keyword(s):  
Low Temperature ◽  
Original Design ◽  
Electrical Conductivities ◽  
Temperature Ranges ◽  
First Time ◽  
In Cells

AbstractThe electrical conductivities of molten KCl-ZrCl4 and CsCl-ZrCl4 mixtures, including their heterogeneous (melt+crystals) ranges, were measured for the first time. The concentration ranges were 65–72 and 66–75 mol.% of ZrCl4, and the temperature ranges were 482–711 and 548–735 K, respectively. The measurements were carried out in cells of an original design.

scholarly journals Study of the island morphology at the early stages of Fe/Mo(110) MBE growth

Open Physics ◽  
2009 ◽  
Vol 7 (2) ◽  
Author(s):  
Dmytro Goykolov ◽  
Miroslav Kotrla
Keyword(s):  
Low Temperature ◽  
Aspect Ratio ◽  
Theoretical Study ◽  
Morphological Changes ◽  
Nearest Neighbors ◽  
Sos Model ◽  
Mbe Growth ◽  
Calculated Dependence ◽  
Average Aspect Ratio ◽  
Higher Temperature

AbstractWe present theoretical study of morphology of Fe islands grown at Mo(110) surface in submonolayer MBE mode. We utilize atomistic SOS model with bond counting, and interactions of Fe adatom up to third nearest neighbors. We performed KMC simulations for different values of adatom interactions and varying temperatures. We have found that, while for the low temperature islands are fat fractals, for the temperature 500 K islands have faceted rhombic-like shape. For the higher temperature, islands acquire a rounded shape. In order to evaluate qualitatively morphological changes, we measured average aspect ratio of islands. We calculated dependence of the average aspect ratio on the temperature, and on the strength of interactions of an adatom with neighbors.

scholarly journals Expression and hepatobiliary transport characteristics of the concentrative and equilibrative nucleoside transporters in sandwich-cultured human hepatocytes

2008 ◽  
Vol 295 (3) ◽  
pp. G570-G580 ◽  
Author(s):  
Rajgopal Govindarajan ◽  
Christopher J. Endres ◽  
Dale Whittington ◽  
Edward LeCluyse ◽  
Marçal Pastor-Anglada ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Rank Order ◽  
Human Hepatocytes ◽  
Nucleoside Transporters ◽  
Hepatic Tissue ◽  
Cultured Hepatocytes ◽  
Hepatobiliary Transport ◽  
Hepatic Diseases ◽  
Nucleoside Drugs

We previously reported that both the concentrative (hCNT) and equilibrative (hENT) nucleoside transporters are expressed in the human liver ( 21 ). Here we report a study that investigated the expression of these transporters (transcripts and proteins) and their role in the hepatobiliary transport of nucleosides/nucleoside drugs using sandwich-cultured human hepatocytes. In the hepatic tissue, the rank order of the mRNA expression of the transporters was hCNT1 ≈ hENT1 > hENT2 ≈ hCNT2 > hCNT3. In sandwich-cultured hepatocytes, the mRNA expression of hCNT2 and hENT2 was comparable to that in hepatic tissue, whereas the expression of corresponding transporters in the two-dimensional hepatocyte cultures was lower. Colocalization studies demonstrated predominant localization of these transporters at the sinusoidal membrane and of hENT1, hCNT1, and hCNT2 at the canalicular membrane. In the sandwich-cultured hepatocytes, ENTs were the major contributors to the transport of thymidine (hENT1, 63%; hENT2, 23%) or guanosine (hENT1, 53%; hENT2, 24%) into the hepatocytes followed by hCNT1 (10%) for thymidine or hCNT2 (23%) for guanosine. Although ribavirin was predominately transported (89%) into the hepatocytes by hENT1, fialuridine (FIAU) was transported by both hENT1 (30%) and hCNTs (61%). The extensively metabolized natural nucleosides were not effluxed into the bile, whereas significant biliary-efflux was observed of FIAU (19%), ribavirin (30%), and formycin B (35%). We conclude that the hepatic activity of hENT1 and hCNT1/2 transporters will determine the in vivo hepatic distribution and therefore the efficacy and/or toxicity of nucleoside drugs used to treat hepatic diseases.

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