Short-term power sources for tokamaks and other physical experiments

The Compass-D tokamak is being planned to move from UKAEA Culham (England) be and reinstalled in IPP Prague (Czech Republic). An overview of Compass-D energetics is described in short. The new power sources have to be designed. Alternative solutions of power sources have been investigated. Ignitrons and mechanical breakers can be replaced by modern high-power semiconductors. With respect to the need of accumulated energy, new technologies of energy storage - supercapacitors and high-speed flywheels, not applied up to now in similar fusion projects, are characterized in comparison with traditional ones - capacitors and big motor-flywheel generators. It is shown that these technologies enhance possibilities in arrangement of power supplies for tokamaks as well as for other high-power demanding experiments with pulse length from fraction to tens of seconds.     

Interaction of Cucurbit[7]uril with Oxime K027, Atropine,and Paraoxon: Risky or Advantageous Delivery System?

Antidotes against organophosphates often possess physicochemical properties that mitigate their passage across the blood–brain barrier. Cucurbit[7]urils may be successfully used as a drug delivery system for bisquaternary oximes and improve central nervous system targeting. The main aim of these studies was to elucidate the relationship between cucurbit[7]uril, oxime K027, atropine, and paraoxon to define potential risks or advantages of this delivery system in a complex in vivo system. For this reason, in silico (molecular docking combined with umbrella sampling simulation) and in vivo (UHPLC—pharmacokinetics, toxicokinetics; acetylcholinesterase reactivation and functional observatory battery) methods were used. Based on our results, cucurbit[7]urils affect multiple factors in organophosphates poisoning and its therapy by (i) scavenging paraoxon and preventing free fraction of this toxin from entering the brain, (ii) enhancing the availability of atropine in the central nervous system and by (iii) increasing oxime passage into the brain. In conclusion, using cucurbit[7]urils with oximes might positively impact the overall treatment effectiveness and the benefits can outweigh the potential risks.     

A Novel Insight into the Cardiotoxicity of Antineoplastic Drug Doxorubicin

Doxorubicin is a commonly used antineoplastic agent in the treatment of many types of cancer. Little is known about the interactions of doxorubicin with cardiac biomolecules. Serious cardiotoxicity including dilated cardiomyopathy often resulting in a fatal congestive heart failure may occur as a consequence of chemotherapy with doxorubicin. The purpose of this study was to determine the effect of exposure to doxorubicin on the changes in major amino acids in tissue of cardiac muscle (proline, taurine, glutamic acid, arginine, aspartic acid, leucine, glycine, valine, alanine, isoleucine, threonine, lysine and serine). An in vitro interaction study was performed as a comparison of amino acid profiles in heart tissue before and after application of doxorubicin. We found that doxorubicin directly influences myocardial amino acid representation even at low concentrations. In addition, we performed an interaction study that resulted in the determination of breaking points for each of analyzed amino acids. Lysine, arginine, β-alanine, valine and serine were determined as the most sensitive amino acids. Additionally we compared amino acid profiles of myocardium before and after exposure to doxorubicin. The amount of amino acids after interaction with doxorubicin was significantly reduced (p = 0.05). This fact points at an ability of doxorubicin to induce changes in quantitative composition of amino acids in myocardium. Moreover, this confirms that the interactions between doxorubicin and amino acids may act as another factor most likely responsible for adverse effects of doxorubicin on myocardium.     

Spreading depression elicited by thermal effects of ultrasonic irradiation of cerebral cortex in rats

Dysbaric osteonecrosis is a major hazard to compressed air workers and an increasing hazard to divers. Symptomless osteonecrosis is best recognised by radiology and it is of fundamental importance that interpretation be reliable and accurate. There is much controversy concerning the significance of bone islands and cystic areas; several authors report bone islands and cystic areas to be up to eight times more frequent in compressed air workers and divers and believe that these represent positive evidence of osteonecrosis. Skeletal radiographs of 100 Royal Navy divers, all of whom were at risk to osteonecrosis were matched for age and rank with 100 controls, none of whom had been exposed to high pressures. The radiographs were interpreted by three radiologists working independently without knowing whether the radiographs were in the diving or control group. It is concluded that bone islands, cystic areas and sclerotic areas, as described in this text, occur with equal frequency in divers as in the normal population and do not represent positive evidence of osteonecrosis. The report includes autopsy studies of the proximal femur and proximal humerus in six diving fatalities. Five bone islands in the proximal humerus and one in the femoral neck were studied in bones removed from five divers. In the sixth case a cyst was seen to develop radiologically in the femoral neck and then reduce in size over 3 years and 10 months. Slab radiographs and histological section in all cases show no evidence of osteonecrosis.     

Transient sex differences in the between-sessions but not in the within-session memory underlying an active place avoidance task in weanling rats.

Spatial abilities were tested in male and female rats by training them to avoid an area in which there was a mild footshock while the arena rotated at 1 revolution/minute. The to-be-avoided area was stable in the coordinates of the room, so extramaze landmarks had to be used for accurate navigation, as the rotation made intramaze cues and substrate-based path integration useless for the avoidance. From Postnatal Day (PD) 19, rats were trained for 22 consecutive days. When the shock area was the same across sessions male rats reached optimal performance on PDs 23–24, 10 days before female rats, but when the location of the shock changed daily there were no sex differences. The results indicate that there are separate memory components underlying spatial competence: a within-session component that develops similarly in male and female rats and a between-sessions component that lasts at least 24 hr and appears earlier in male than in female rats. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The different expression of proteins recognized by monoclonal anti-heat shock protein 70 (hsp70) antibody in human colonic diseases

Analysis of the expression of hsp70 (70 kDa heat-shock proteins) in normal and pathological tissues might prove their potential diagnostic and prognostic values. In the present study, we combined high-resolution two-dimensional polyacrylamide gel electrophoresis with immunoblotting to study hsp70 expression in normal, preneoplastic and neoplastic colonic mucosa. By monoclonal anti-hsp70 antibody, recognizing both the constitutive and inducible forms of hsp70, we have detected six charge isoforms localized in the pH 5.1-5.3 range and in the molecular mass range of 68-69 kDa in normal colonic mucosa. Immunostaining of hsp70 in polypous and malignant tissues revealed qualitative as well as quantitative changes in the expression of more acidic isoforms of hsp70 in comparison with normal tissue. Furthermore, the different basic isoforms of hsp70 were detected in chronically inflamed colonic mucosa from patients suffering from ulcerative colitis (UC) or Crohn's disease (CD). Besides the standard hsp70 protein pattern, additional proteins with molecular masses of about 39, 40, 74 and 75 kDa were variably immunostained in normal and pathological specimens. These observations suggest that hsp70 expression may be closely linked to disease etiology and/or pathophysiology.     

Place cells and place navigation

The assumption that hippocampal place cells (PCs) form the neural substrate of cognitive maps can be experimentally tested by comparing the effect of experimental interventions on PC activity and place navigation. Conditions that interfere with place navigation (darkness, cholinergic blockade) but leave PC activity unaffected obviously disrupt spatial memory at a post-PC level. Situations creating a conflict between egocentric and allocentric orientation (place navigation in the Morris water maze filled with slowly rotating water) slow down spatial learning. PC recording in rats searching food pellets in a rotating arena makes it possible to determine which firing fields are stable relative to the room (allocentrically dependent on sighted extramaze landmarks), to the surface of the arena (dependent on egocentric path integration mechanisms and intra-arena cues), or disappear during rotation. Such comparison is made possible by the computerized tracking system simultaneously displaying a rat's locomotion and the respective firing rate maps both in the room reference and arena reference frames. More severe conflict between allocentric and egocentric inputs is produced in the field clamp situation when the rat searching food in a ring-shaped arena is always returned by rotation of the arena to the same allocentric position. Ten-minute exposure to this condition caused subsequent disintegration or remapping of 70% PCs (n = 100). Simultaneous examination of PC activity and navigation is possible in the place avoidance task. A rat searching food in a stationary or rotating arena learns to avoid an allocentrically or egocentrically defined location where it receives mild electric footshock. In the place preference task the rat releases pellet delivery by entering an unmarked goal area and staying in it for a criterion time. Both tasks allow direct comparison of the spatial reference frames used by the PCs and by the behaving animal.