Corrosion cast study of the canine hepatic veins

This study presents a detailed description of the distribution, diameters and drainage patterns of hepatic veins on the basis of the corrosion cast analysis in 18 dogs. We classified the hepatic veins in three main groups: the right hepatic veins of the caudate process and right lateral liver lobe, the middle hepatic veins of the right medial and quadrate lobes and the left hepatic veins of both left liver lobes and the papillary process. The corrosion cast study showed that the number of the veins in the Nomina Anatomica Veterinaria and most anatomical textbooks is underestimated. The number of various-sized hepatic veins of the right liver division ranged from 3 to 5 and included 1 to 4 veins from the caudate process and 2 to 4 veins from the right lateral liver lobe. Generally, in all corrosion casts, one middle-sized vein from the right part of the right medial lobe, which emptied separately in the caudal vena cava, was established. The other vein was a large-sized vein from the remainder of the central division, which frequently joined the common left hepatic vein from the left liver lobes. The common left hepatic vein was the largest of all the aforementioned hepatic veins.

Poboljšavanje svojstava brzoreznog čelika 1.3302u vrućem stanju

Laboratory investigation of hot workability of 1.3302 high speed steel was carried out and its improving was achieved. Hot compression tests for the determination of optimal soaking temperature as well as for the study of hot workability in temperature range 1150-850 ºC, strain rates range 0,001-6 s–1 and applied strain up to 0,9 were performed. Microstructure of deformed specimen was analyzed. Apparent activation energies for hot working for upper and for lower temperature range were calculated. Onsets of dynamical recrystallization for applied deformation conditions on the basis of calculated strain hardening ratewere determined. Extending of hot working temperature range at its lower limit, i.e. down to 850 ºC, by applying optimal soaking temperature was obtained.Data su laboratorijska istraživanja prerađivačkih svojstva brzoreznog čelika 1.3302 u vrućem stanju koji su doprinijeli poboljšanju tih svojstava. Izvedeni su pokusi vrućeg sabijanja za određivanje temperature zagrijavanja kao i prerađivačkih svojstva u temperaturnom rasponu 1 150-850 ºC, brzinom deformacije 0,001-6 s–1 i stupnja deformacije do 0,9. Analizirana je mikrostruktura deformiranih proba.Izračunane su prividne aktivacijske energije za vruću preradu za gornje i donje temperaturno područje. Počeci dinamičke rekristalizacije za primijenjene uvjete deformacije utvrđeni su na temelju izračuna brzine deformacijskog očvršćavanja. Primjenjujući optimalno temperaturu zagrijavanja dobiveno je povećanje vrućeg radnog temperaturnog raspona na svojoj donjoj granici, odnosno do 850 ºC

Increasing of hot workability of 1.3302HIGH speed steel

Laboratory investigation of hot workability of 1.3302 high speed steel was carried out and its improving was achieved. Hot compression tests for the determination of optimal soaking temperature as well as for the study of hot workability in temperature range 1150-850 ºC, strain rates range 0,001-6 s<sup>–1/sup> and applied strain up to 0,9 were performed. Microstructure of deformed specimen was analyzed. Apparent activation energies for hot working for upper and for lower temperature range were calculated. Onsets of dynamical recrystallization for applied deformation conditions on the basis of calculated strain hardening ratewere determined. Extending of hot working temperature range at its lower limit, i.e. down to 850 ºC, by applying optimal soaking temperature was obtained

Primjena novo razvijenih testova sa grijanjem i unutarnjim hlađenjem uzoraka od alatnog čelika za različite primjene

In this study two new tests were developed, i.e., with continuous internal water cooling as well as discontinuous internal water and air cooling. It was proved that the first type of testing is appropriate for simulating the time course of the temperature at a selected depth of a thermally loaded, hot-working die surface layer, i.e., the temperature field on the die surface layer. The second type of testing is appropriate for a study of the thermal fatigue resistance of a tool material.U ovom istraživanju razvijeni su dva nova testa, tj. test sa kontinuiranom unutarnjim vodenim hlađenjem, kao i test sa diskontinuiranom unutarnjim vodenim i zračnim hlađenjem. Dokazano je da je prvi tip ispitivanja primjeran za simulaciju vremenske raspodjele temperature na odabranoj dubini termalno opterećene površine alata za vruću preradu. Druga vrsta ispitivanja je prikladno za proučavanje otpora termalnog zamora alatnog materijala

On the increase of intrinsic workability and hot working temperature range of M42 ledeburitic super high speed steel in as-cast and wrought states

In order to remain competitive to powder metallurgy and spray forming, further improvements of a classical production route are needed and desired. This paper describes the means by which the intrinsic hot deformability may be improved and the temperature range of the safe hot working extended for AISI M42 super high speed steel, one of the most challenging materials with respect to hot deformability. A special hot compression procedure is described to determine appropriate soaking temperatures of as-cast and semi-wrought states. Moreover, conventional hot compression tests in the extended temperature range (850–1150 °C) and strain rates range 0.001–5 s−1 were carried out. The complex behaviour of carbides is discussed, which depends on the soaking temperature and time, deformation temperature and strain rate. Deformation conditions for improved crushing of initial eutectic carbides networks during the first stages of hot working are identified. Apparent activation energies for hot working in two temperature ranges and constants of the hyperbolic sine function are determined. The microstructure and respective carbides are characterised by field emission scanning electron microscope, optical microscopy, X-ray diffraction and the results compared to equilibrium thermodynamic calculations using ThermoCalc.This work was supported by the Slovenian Research Agency (ARRS) under programme grants P2-0344 and P2-0268

O utjecaju ljudskog faktora na mehanička svojstva u istiskivanju aluminija na toplo

A non-parametric model was proposed for modelling the influence of different technological and chemical parameters on the mechanical properties of the 6082 aluminium alloys during the hot extrusion process with a special consideration of human factor. It was shown that human factor (influence of process engineers) was important and that it could be efficiently modeled and taken into account by the proposed Conditional Average Estimator (CAE) method. Production might be improved (optimized) by a proper education and/or by eliminating critical process engineers. It was found that the highest values for elongation and yield stress did not coincide with the range of the most frequent combinations of input parameters.Predložen je neparametarski model za modeliranje utjecaja različitih tehnoloških i kemijskih parametara na mehanička svojstva aluminijske legure 6082 tijekom istiskivanja na toplo s posebnim razmatranjem na ljudskom faktorom. Pokazano je, da je ljudski faktor (utjecaj proces inženjera) važan i da se može efikasno uzeti u obzir s predloženom CAE metodom. Proizvodnja se može poboljšati (optimirati) uz odgovarajuće obrazovanje i/ili uklanjanje kritičnih proces inženjera. Zapaženo je, da se najviše vrijednosti produljenja i naprezanja tečenja ne podudaraju s područjem najčešćih kombinacija ulaznih parametara

Obesity resistant mechanisms in the Lean polygenic mouse model as indicated by liver transcriptome and expression of selected genes in skeletal muscle

<p>Abstract</p> <p>Background</p> <p>Divergently selected Lean and Fat mouse lines represent unique models for a polygenic form of resistance and susceptibility to obesity development. Previous research on these lines focused mainly on obesity-susceptible factors in the Fat line. This study aimed to examine the molecular basis of obesity-resistant mechanisms in the Lean line by analyzing various fat depots and organs, the liver transcriptome of selected metabolic pathways, plasma and lipid homeostasis and expression of selected skeletal muscle genes.</p> <p>Results</p> <p>Expression profiling using our custom Steroltalk v2 microarray demonstrated that Lean mice exhibit a higher hepatic expression of cholesterol biosynthesis genes compared to the Fat line, although this was not reflected in elevation of total plasma or liver cholesterol. However, FPLC analysis showed that protective HDL cholesterol was elevated in Lean mice. A significant difference between the strains was also found in bile acid metabolism. Lean mice had a higher expression of <it>Cyp8b1</it>, a regulatory enzyme of bile acid synthesis, and the <it>Abcb11 </it>bile acid transporter gene responsible for export of acids to the bile. Additionally, a higher content of blood circulating bile acids was observed in Lean mice. Elevated HDL and upregulation of some bile acids synthesis and transport genes suggests enhanced reverse cholesterol transport in the Lean line - the flux of cholesterol out of the body is higher which is compensated by upregulation of endogenous cholesterol biosynthesis. Increased skeletal muscle <it>Il6 </it>and <it>Dio2 </it>mRNA levels as well as increased activity of muscle succinic acid dehydrogenase (SDH) in the Lean mice demonstrates for the first time that changes in muscle energy metabolism play important role in the Lean line phenotype determination and corroborate our previous findings of increased physical activity and thermogenesis in this line. Finally, differential expression of <it>Abcb11 </it>and <it>Dio2 </it>identifies novel strong positional candidate genes as they map within the quantitative trait loci (QTL) regions detected previously in crosses between the Lean and Fat mice.</p> <p>Conclusion</p> <p>We identified novel candidate molecular targets and metabolic changes which can at least in part explain resistance to obesity development in the Lean line. The major difference between the Lean and Fat mice was in increased liver cholesterol biosynthesis gene mRNA expression, bile acid metabolism and changes in selected muscle genes' expression in the Lean line. The liver <it>Abcb11 </it>and muscle <it>Dio2 </it>were identified as novel positional candidate genes to explain part of the phenotypic difference between the Lean and Fat lines.</p

Implementation of newly developed tests with heated and internally cooled tool steel samples for different applications

In this study two new tests were developed, i.e., with continuous internal water cooling as well as discontinuous internal water and air cooling. It was proved that the first type of testing is appropriate for simulating the time course of the temperature at a selected depth of a thermally loaded, hot-working die surface layer, i.e., the temperature field on the die surface layer. The second type of testing is appropriate for a study of the thermal fatigue resistance of a tool material

Chromosomal congenital anomalies and residence near hazardous waste landfill sites.

Previous findings of the EUROHAZCON study showed a 33% increase in risk of non-chromosomal anomalies near hazardous waste landfill sites. Here, we studied 245 cases of chromosomal anomalies and 2412 controls who lived near 23 such sites in Europe. After adjustment for confounding by maternal age and socioeconomic status, we noted a higher risk of chromosomal anomalies in people who lived close to sites (0-3 km) than in those who lived further away (3-7 km; odds ratio 1.41, 95% CI 1.00-1.99). Our results suggest an increase in risk of chromosomal anomalies similar to that found for non-chromosomal anomalies