Rugalmas rácsok kollektiv dinamikája rendezetlen potenciál térben = Collective Dynamics of Elastic Lattices in Disorder Potential

A projekt keretében nagyáramú transzportméréseket végeztünk a magashőmérsékletű szupravezetők prototípusának tekinthető Bi2Sr2CaCu2O8 (BSCCO) egykristályokon. Vizsgálataink a következő új eredményekhez vezettek: 1. Az alacsonyhőmérsékleti vortexüveg fázis egy tartományában megfigyelt metastabil viselkedés megjelenése nem fázisátmenet, hanem egy dinamikus átmenetet, amely során a vortexek termikus relaxációs ideje hosszabbá válik, mint a kísérlet időskálája. 2. A disszipáció a szupravezető és normális állapotot elválasztó front mozgásával fokozatosan terjed a mintában. 3. A szabad vortexmozgás (FFF) disszipatív dinamikája nem írható le a széleskörűen elfogadott Bardeen-Stephen-törvénnyel, amely szerint az ellenállás lineárisan közelít a nem szupravezető értékhez, ha a mágneses tér a felső kritikus mágneses térhez tart, hanem egy 3/4 kitevőjű hatványfüggvénnyel irható le. 4. A szilárd vortex fázisban a mágneses ellenállás telítődik nagy mágneses térnél. A jelenséget a szomszédos szupravezető síkokon a vortexmagok közötti kvázirészecske-vezetőképesség segítségével értelmeztük. 5. Szilárd vortex fázisban nagy áramoknál Hall-feszültség jelenik meg, mely előjelet vált a mágneses tér irányának változtatásakor. A Hall-feszültség megjelenésének küszöbárama két nagyságrenddel nagyobb, mint a longitudinális feszültségé. A jelenséget a vortexek dinamikus rendeződésével értelmeztük. | Our programme on high current electrical transport in Bi2Sr2CaCu208 (BSCCO), chosen as the prototypical high Tc cuprate superconductor, has brought new understanding to several aspects: 1.The portion of the low temperature vortex glass phase exhibiting metastability is not a new phase but a dynamic crossover at which thermal relaxation of the vortices into the disorder slows to the time scale of the experiments. 2. Dissipation sets in progressively as a superconducting/normal front moves into the sample. 3.The free flux flow viscous dynamics does not obey the widely accepted Bardeen- Stephen law that the resistivity approach its non-superconducting value linearly with field to the upper critical field, but rather a displays a 3 power law. 4.The magneto resistance in the vortex solid phase saturates at high field. This is interpreted as arising from extra c-axis conduction along the cores of vortices which have time averaged out the disorder and become aligned from plane to plane to displace as a 3-D Abrikosov like solid. 5.In the vortex solid phase a real Hall potential, one which changes sign on magnetic field reversal, appears only at very high currents, two orders of magnitude beyond the depinning threshold. We ascribe this to motion along a channel from which escape into unguided free flux flow exhibiting a real Hall effect requires a minimum lateral force. The large factor between depinning and dechanneling is attributed to the increased current penetration accompanying vortex alignment

Clusterin secretion is attenuated by the proinflammatory cytokines interleukin‐1β and tumor necrosis factor‐α in models of cartilage degradation

The protein clusterin has been implicated in the molecular alterations that occur in articular cartilage during osteoarthritis (OA). Clusterin exists in two isoforms with opposing functions, and their roles in cartilage have not been explored. The secreted form of clusterin (sCLU) is a cytoprotective extracellular chaperone that prevents protein aggregation, enhances cell proliferation and promotes viability, whereas nuclear clusterin acts as a pro-death signal. Therefore, these two clusterin isoforms may be putative molecular markers of repair and catabolic responses in cartilage and the ratio between them may be important. In this study, we focused on sCLU and used established, pathophysiologically relevant, in vitro models to understand its role in cytokine-stimulated cartilage degradation. The secretome of equine cartilage explants, osteochondral biopsies and isolated unpassaged chondrocytes was analyzed by western blotting for released sCLU, cartilage oligomeric protein (COMP) and matrix metalloproteinases (MMP) 3 and 13, following treatment with the proinflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α. Release of sulfated glycosaminoglycans (sGAG) was determined using the dimethylmethylene blue assay. Clusterin messenger RNA (mRNA) expression was quantified by quantitative real-time polymerase chain reaction. MMP-3, MMP-13, COMP, and sGAG release from explants and osteochondral biopsies was elevated with cytokine treatment, confirming cartilage degradation in these models. sCLU release was attenuated with cytokine treatment in all models, potentially limiting its cytoprotective function. Clusterin mRNA expression was down-regulated 7-days post cytokine stimulation. These observations implicate sCLU in catabolic responses of chondrocytes, but further studies are required to evaluate its role in OA and its potential as an investigative biomarker

Causative Agent of Canine Heartworm (Dirofilaria immitis) Detected in Wild Lemurs

The lemurs of Madagascar are threatened by human activities. We present the first molecular detection of canine heartworm (Dirofilaria immitis) in a wild non-human primate, the mouse lemur (Microcebus rufus). Zoonotic D. immitis infection has been associated with clinical pathology that includes serious and often fatal cardiac and pulmonary reactions. With human encroachment and associated increases in free-roaming dog populations in Madagascar, we examined lemurs for zoonotic canid pathogens. D. immitis presents a new potential conservation threat to lemurs. We highlight the need for wide-ranging and effective interventions, particularly near protected areas, to address this growing conservation issue

The effects of simulated wildland firefighting tasks on core temperature and cognitive function under very hot conditions

Background: The severity of wildland fires is increasing due to continually hotter and drier summers. Firefighters are required to make life altering decisions on the fireground, which requires analytical thinking, problem solving, and situational awareness. This study aimed to determine the effects of very hot (45°C; HOT) conditions on cognitive function following periods of simulated wildfire suppression work when compared to a temperate environment (18°C; CON). Methods: Ten male volunteer firefighters intermittently performed a simulated fireground task for 3 h in both the CON and HOT environments, with cognitive function tests (paired associates learning and spatial span) assessed at baseline (cog 1) and during the final 20-min of each hour (cog 2, 3, and 4). Reaction time was also assessed at cog 1 and cog 4. Pre- and post- body mass were recorded, and core and skin temperature were measured continuously throughout the protocol. Results: There were no differences between the CON and HOT trials for any of the cognitive assessments, regardless of complexity. While core temperature reached 38.7°C in the HOT (compared to only 37.5°C in the CON; p < 0.01), core temperature declined during the cognitive assessments in both conditions (at a rate of -0.15 ± 0.20°C·hr-1 and -0.63 ± 0.12°C·hr-1 in the HOT and CON trial respectively). Firefighters also maintained their pre-exercise body mass in both conditions, indicating euhydration. Conclusions: It is likely that this maintenance of euhydration and the relative drop in core temperature experienced between physical work bouts was responsible for the preservation of firefighters\u27 cognitive function in the present study

The Effects of Simulated Wildland Firefighting Tasks on Core Temperature and Cognitive Function under Very Hot Conditions

Background The severity of wildland fires is increasing due to continually hotter and drier summers. Firefighters are required to make life altering decisions on the fireground, which requires analytical thinking, problem solving, and situational awareness. This study aimed to determine the effects of very hot (45°C; HOT) conditions on cognitive function following periods of simulated wildfire suppression work when compared to a temperate environment (18°C; CON). Methods Ten male volunteer firefighters intermittently performed a simulated fireground task for 3 h in both the CON and HOT environments, with cognitive function tests (paired associates learning and spatial span) assessed at baseline (cog 1) and during the final 20-min of each hour (cog 2, 3, and 4). Reaction time was also assessed at cog 1 and cog 4. Pre- and post- body mass were recorded, and core and skin temperature were measured continuously throughout the protocol. Results There were no differences between the CON and HOT trials for any of the cognitive assessments, regardless of complexity. While core temperature reached 38.7°C in the HOT (compared to only 37.5°C in the CON; p < 0.01), core temperature declined during the cognitive assessments in both conditions (at a rate of −0.15 ± 0.20°C·hr−1 and −0.63 ± 0.12°C·hr−1 in the HOT and CON trial respectively). Firefighters also maintained their pre-exercise body mass in both conditions, indicating euhydration. Conclusions It is likely that this maintenance of euhydration and the relative drop in core temperature experienced between physical work bouts was responsible for the preservation of firefighters' cognitive function in the present study

The effect of diet on the physical and mental development of children: views of parents and teachers in four European countries

Although the impact of diet on physical health is an important public health issue, less attention has been devoted to the relationship between nutrition and children's mental development. The views of parents and teachers about the extent to which diet affects physical and mental development of children were compared in four European countries. An online questionnaire (developed in English and translated) was circulated through a market research agency. Participants were parents or teachers of children aged 4-10 years without learning or behavioural issues. Questionnaires were returned by 1606 parents (401 in England, Germany and Hungary; 403 in Spain) and 403 teachers (100 in each country, except for 103 in Hungary). Teachers were older than parents (35·3 % v. 18·3 % over 45 years; P<0·001) and less likely to smoke (15·9 % v. 26·3 %, P<0·001). There was no difference between the proportions of parents and teachers who felt that a child's physical development depended very much/extremely (v. moderately/slightly/not at all) on diet (overall 79·8 %). Lower proportions of both groups thought that mental development was very much/extremely influenced by diet (67·4 %). In the regression modelling, believing that physical and mental performance was greatly influenced by diet was significantly and positively associated with living in Hungary, scoring higher on a measure of General Health Interest and (parents only) level of education attained. Differences existed among countries in most views. Lower levels of awareness of the importance of diet for brain development and cognition (compared with physical health outcomes) indicate the potential for educating consumers, especially parents with lower educational attainment

Adjuvant endocrine therapy after breast cancer: a qualitative study of factors associated with adherence.

INTRODUCTION: Despite evidence of the efficacy of adjuvant endocrine therapy (AET) in reducing the risk of recurrence and mortality after treatment for primary breast cancer, adherence to AET is suboptimal. This study aimed to explore factors that influence adherence and nonadherence to AET following breast cancer to inform the development of supportive interventions. METHODS: Interviews were conducted with 32 women who had been prescribed AET, 2-4 years following their diagnosis of breast cancer. Both adherers (n=19) and nonadherers (n=13) were recruited. The analysis was conducted using the Framework approach. RESULTS: Factors associated with adherence were as follows: managing side effects including information and advice on side effects and taking control of side effects, supportive relationships, and personal influences. Factors associated with nonadherence were as follows: burden of side effects, feeling unsupported, concerns about long-term AET use, regaining normality, including valuing the quality of life over length of life, and risk perception. CONCLUSION: Provision of timely information to prepare women for the potential side effects of AET and education on medication management strategies are needed, including provision of timely and accurate information on the efficacy of AET in reducing breast cancer recurrence and on potential side effects and ways to manage these should they arise. Trust in the doctor-patient relationship and clear patient pathways for bothersome side effects and concerns with AET are important. Training and education on AET for GPs should be considered alongside novel care pathways such as primary care nurse cancer care review and community pharmacist follow-up

Investigation of a Cluster of Sequence Type 22 Methicillin-Resistant Staphylococcus aureus Transmission in a Community Setting.

BACKGROUND: Whole-genome sequencing (WGS) has typically been used to confirm or refute hospital/ward outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) identified through routine practice. However, appropriately targeted WGS strategies that identify routinely "undetectable" transmission remain the ultimate aim. METHODS: WGS of MRSA isolates sent to a regional microbiological laboratory was performed as part of a 12-month prospective observational study. Phylogenetic analyses identified a genetically related cluster of E-MRSA15 isolated from patients registered to the same general practice (GP) surgery. This led to an investigation to identify epidemiological links, find additional cases, and determine potential for ongoing transmission. RESULTS: We identified 15 MRSA-positive individuals with 27 highly related MRSA isolates who were linked to the GP surgery, 2 of whom died with MRSA bacteremia. Of the 13 cases that were further investigated, 11 had attended a leg ulcer/podiatry clinic. Cases lacked epidemiological links to hospitals, suggesting that transmission occurred elsewhere. Environmental and staff screening at the GP surgery did not identify an ongoing source of infection. CONCLUSIONS: Surveillance in the United Kingdom shows that the proportion of MRSA bacteremias apportioned to hospitals is decreasing, suggesting the need for greater focus on the detection of MRSA outbreaks and transmission in the community. This case study confirms that the typically nosocomial lineage (E-MRSA15) can transmit within community settings. Our study exemplifies the continued importance of WGS in detecting outbreaks, including those which may be missed by routine practice, and suggests that universal WGS of bacteremia isolates may help detect outbreaks in low-surveillance settings