Polish Academy of Sciences

Warsaw, Poland

The Polish Academy of science, headquartered in Warsaw, is the top Polish institution having the character of an academy of science. Being a society of distinguished scholars as well as a network of research institutes, it is responsible for spearheading the development of science in Poland. It was established in 1951, during the period of Poland People's Republic. Wikipedia.

Time filter
Source Type

News Article | May 11, 2017
Site: www.eurekalert.org

At very high energies, the collision of massive atomic nuclei in an accelerator generates hundreds or even thousands of particles that undergo numerous interactions. At the Institute of Nuclear Physics of the Polish Academy of Sciences in Cracow, Poland it has been shown that the course of this complex process can be represented by a surprisingly simple model: extremely hot matter moves away from the impact point, stretching along the original flight path in streaks, and the further the streak is from the plane of the collision, the greater its velocity. When two massive atomic nuclei collide at high energies, the most exotic form of matter is formed: the quark-gluon plasma behaving like a perfect fluid. The theoretical considerations of physicists from the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN) in Cracow, Poland show that after impact the plasma forms into streaks along the direction of impact, moving faster the further away it moves from the collision axis. The model, its predictions and the effects of their confrontation with hitherto experimental data are presented in the journal Physical Review C. Collisions of atomic nuclei occur extremely rapidly and at distances of merely hundreds of femtometres (i.e. hundreds of millionths of one billionth of a metre). The physical conditions are exceptionally sophisticated and direct observation of the phenomenon is not currently possible. In such situations, science copes by constructing theoretical models and confronting their predictions with the data collected in experiments. In the case of these collisions, however, a huge disadvantage is that the resulting conglomerate of particles is the quark-gluon plasma. Interactions between quarks and gluons are dominated by forces that are so strong and complex that modern physics is not capable of describing them precisely. "Our group decided to focus on the electromagnetic phenomena occurring during the collision because they are much easier to express in the language of mathematics. As a result, our model proved to be simple enough for us to employ the principles of energy and momentum conservation without too much trouble. Later on, we found that despite the adopted simplifications the model predictions remain at least 90% consistent with experimental data", says Dr. Andrzej Rybicki (IFJ PAN). Massive atomic nuclei accelerated to high velocities, observed in the laboratory, are flattened in the direction of motion as a result of the effects of the theory of relativity. When two such proton-neutron 'pancakes' fly towards each other, the collision is generally not central: only some of the protons and neutrons of one nucleus reach the other, entering into violent interactions and forming the quark-gluon plasma. At the same time, some of the external fragments of the nuclear pancakes do not encounter any obstacles on their way and continue their uninterrupted flight; in the jargon of physicists they are called spectators. "Our work was inspired by data collected in earlier experiments with nuclear collisions, including these made at the SPS accelerator. The electromagnetic effects occurring in these collisions that we examined showed that the quark-gluon plasma moves at a higher velocity the closer it is to the spectators", says Dr. Rybicki. In order to reproduce this course of the phenomenon, the physicists from IFJ PAN decided to divide the nuclei along the direction of movement into a series of strips - 'bricks'. Each nucleus in cross section thus looked like a pile of stacked bricks (in the model their height was one femtometre). Instead of considering the complex strong interactions and flows of momentum and energy between hundreds and thousands of particles, the model reduced the problem to several dozen parallel collisions, each occurring between two proton-neutron bricks. The IFJ PAN scientists confronted the predictions of the model with data collected from collisions of massive nuclei measured by the NA49 experiment at the Super Proton Synchrotron (SPS). This accelerator is located at the CERN European Nuclear Research Organization near Geneva, where one of its most important tasks now is to accelerate particles shot into the LHC accelerator. "Due to the scale of technical difficulties, the NA49 experiment's results are subject to specific measurement uncertainties that are difficult to completely reduce or eliminate. In reality, the accuracy of our model can even be greater than the already mentioned 90%. This entitles us to say that even if there were any additional, still not included, physical mechanisms in the collisions they should no longer significantly affect the theoretical framework of the model", comments doctoral student Miroslaw Kielbowicz (IFJ PAN). After developing the model of collisions of 'brick stacks', the IFJ PAN researchers discovered that a very similar theoretical structure, called the fire streak model, had been proposed by a group of physicists from the Lawrence Berkeley Laboratory (USA) and the Saclay Nuclear Research Centre in France - already in 1978. "The previous model of fire streaks which, in fact, we mention in our publication, was built to describe other collisions occurring at lower energies. We have created our structure independently and for a different energy range", says Prof. Antoni Szczurek (IFJ PAN, University of Rzeszow) and emphasizes: "The existence of two independent models based on a similar physical idea and corresponding to measurements in different energy ranges of collisions increases the probability that the physical basis on which these models are built is correct". The Cracow fire streak model provides new information on the expansion of quark-gluon plasma in high energy collisions of massive atomic nuclei. The study of these phenomena is being further extended in the framework of another international experiment, NA61/SHINE at the SPS accelerator. The research of the IFJ PAN group is being financed by the SONATA BIS grant from the National Science Centre. The Henryk Niewodniczanski Institute of Nuclear Physics (IFJ PAN) is currently the largest research institute of the Polish Academy of Sciences. The broad range of studies and activities of IFJ PAN includes basic and applied research, ranging from particle physics and astrophysics, through hadron physics, high-, medium-, and low-energy nuclear physics, condensed matter physics (including materials engineering), to various applications of methods of nuclear physics in interdisciplinary research, covering medical physics, dosimetry, radiation and environmental biology, environmental protection, and other related disciplines. The average yearly yield of the IFJ PAN encompasses more than 500 scientific papers in the Journal Citation Reports published by the Thomson Reuters. The part of the Institute is the Cyclotron Centre Bronowice (CCB) which is an infrastructure, unique in Central Europe, to serve as a clinical and research centre in the area of medical and nuclear physics. IFJ PAN is a member of the Marian Smoluchowski Krakow Research Consortium: "Matter-Energy-Future" which possesses the status of a Leading National Research Centre (KNOW) in physics for the years 2012-2017. The Institute is of A+ Category (leading level in Poland) in the field of sciences and engineering. Dr. Andrzej Rybicki The Institute of Nuclear Physics of the Polish Academy of Sciences tel.: +48 12 6628447 email: andrzej.rybicki@ifj.edu.pl Prof. Antoni Szczurek The Institute of Nuclear Physics of the Polish Academy of Sciences tel. +48 12 6628212 email: antoni.szczurek@ifj.edu.pl "Implications of energy and momentum conservation for particle emission in A+A collisions at energies available at the CERN Super Proton Synchrotron" http://shine. The website of the SHINE experiment. http://www. The website of the European Organization for Nuclear Research (CERN). http://www. The website of the Institute of Nuclear Physics of the Polish Academy of Sciences. http://press. Press releases of the Institute of Nuclear Physics of the Polish Academy of Sciences. Fragments of extremely hot matter, produced in the collision of heavy atomic nuclei at the SPS accelerator at the European CERN centre, move away from each other at high velocities, forming streaks along the direction of the collision. (Source: IFJ PAN, Iwona Sputowska)

Kreiner G.,Polish Academy of Sciences
Frontiers in Cellular Neuroscience | Year: 2015

Neurodegenerative diseases are one of the main causes of mental and physical disabilities. Neurodegeneration has been estimated to begin many years before the first clinical symptoms manifest, and even a prompt diagnosis at this stage provides very little advantage for a more effective treatment as the currently available pharmacotherapies are based on disease symptomatology. The etiology of the majority of neurodegenerative diseases remains unknown, and even for those diseases caused by identified genetic mutations, the direct pathways from gene alteration to final cell death have not yet been fully elucidated. Advancements in genetic engineering have provided many transgenic mice that are used as an alternative to pharmacological models of neurodegenerative diseases. Surprisingly, even the models reiterating the same causative mutations do not fully recapitulate the inevitable neuronal loss, and some fail to even show phenotypic alterations, which suggests the possible existence of compensatory mechanisms. A better evaluation of these mechanisms may not only help us to explain why neurodegenerative diseases are mostly late-onset disorders in humans but may also provide new markers and targets for novel strategies designed to extend neuronal function and survival. The aim of this mini-review is to draw attention to this underexplored field in which investigations may reasonably contribute to unveiling hidden reserves in the organism. © 2015 Kreiner.

Nikiforuk A.,Polish Academy of Sciences
Behavioural Brain Research | Year: 2012

Preclinical data demonstrate that the selective blockade of 5-HT7 receptors produces antidepressant-like behavioural effects. Although the involvement of 5-HT7 receptors in cognitive processes has been previously suggested, little is known about their role in the prefrontal cortex (PFC)-dependent processes that may be impaired in stress-related states. According to our previous study, repeated restraint stress induces the long-lasting cognitive impairment in a rat model of PFC-dependent attentional set-shifting task (ASST). Therefore, the first aim of the present experiments was to examine the impact of the selective 5-HT7 receptor antagonist, SB-269970, on ASST performance of stressed and control rats. Since the selective blockade of 5-HT7 receptors has been previously demonstrated to enhance the behavioural effects of antidepressants, the second goal was to examine the impact of the joint administration of inactive doses of SB-269970 and escitalopram in the ASST. SB-269970 (0.3 and 1. mg/kg) given to stressed rats 30. min before testing reversed the restraint-induced impairment of the extra-dimensional (ED) set-shifting ability. Additionally, SB-269970 (1. mg/kg) also improved ED performance of the unstressed control group. Moreover, SB-269970, given at an inactive dose, enhanced the pro-cognitive efficacy of escitalopram. In conclusion, these results highlight the possibility that 5-HT7 receptor antagonism may represent a useful pharmacological approach in the treatment of frontal-like cognitive disturbances in stress-related psychiatric disorders. © 2011 Elsevier B.V.

Streptozotocin (STZ), a glucosamine-nitrosourea compound derived from soil bacteria and originally developed as an anticancer agent, in 1963 has been found to induce diabetes in experimental animals. Since then, systemic application of STZ became the most frequently studied experimental model of insulin-dependent (type 1) diabetes. The compound is selectively toxic toward insulin-producing pancreatic beta cells, which is explained as the result of its cellular uptake by the low-affinity glucose transporter 2 (GLUT2) protein located in their cell membranes. STZ cytotoxicity is mainly due to DNA alkylation which results in cellular necrosis. Besides pancreatic beta cells, STZ applied systemically damages also other organs expressing GLUT2, such as kidney and liver, whereas brain is not affected directly because blood-brain barrier lacks this transporter protein. However, single or double intracerebroventricular (icv) STZ injection(s) chronically decrease cerebral glucose uptake and produce multiple other effects that resemble molecular, pathological, and behavioral features of Alzheimer’s disease (AD). Taking into consideration that glucose hypometabolism is an early and persistent sign of AD and that Alzheimer’s brains present features of impaired insulin signaling, icv STZ injections are exploited by some investigators as a non-transgenic model of this disease and used for preclinical testing of pharmacological therapies for AD. While it has been assumed that icv STZ produces cerebral glucose hypometabolism and other effects directly through desensitizing brain insulin receptors, the evidence for such mechanism is poor. On the other hand, early data on insulin immunoreactivity showed intense insulin expression in the rodent brain, and the possibility of local production of insulin in the mammalian brain has never been conclusively excluded. Also, there are GLUT2-expressing cells in the brain, in particular in the circumventricular organs and hypothalamus; some of these cells may be involved in glucose sensing. Thus, icv STZ may damage brain glucose insulin producing cells and/or brain glucose sensors. Mechanistic explanation of the mode of action of icv STZ, which is currently lacking, would provide a valuable contribution to the field of animal models of Alzheimer’s disease. © 2015, The Author(s).

Many pathologies of the central nervous system (CNS) originate from excess of reactive free radicals, notably reactive oxygen species (ROS), and oxidative stress. A phenomenon which usually runs in parallel with oxidative stress is unsaturated lipid peroxidation, which, via a chain reaction, contributes to the progression of disbalanced redox homeostasis. Among long-chain (LC) polyunsaturated fatty acids (PUFAs) abundantly occurring in the CNS, docosahexaenoic acid (DHA), a member of w-3 LC-PUFAs, deserves special attention, as it is avidly retained and uniquely concentrated in the nervous system, particularly in retinal photoreceptors and synaptic membranes; owing to the presence of the six double bonds between carbon atoms in its polyene chain (C=C), DHA is exquisitely sensitive to oxidative damage. In addition to oxidative stress and LC-PUFAs peroxidation, other stress-related mechanisms may also contribute to the development of various CNS malfunctions, and a good example of such mechanisms is the process of lipofuscin formation occurring particularly in the retina, an integral part of the CNS. The retinal lipofuscin is formed and accumulated by the retinal pigment epithelial (RPE) cells as a consequence of both visual process taking place in photoreceptor-RPE functional complex and metabolic insufficiency of RPE lysosomal compartment. Among various retinal lipofuscin constituents, bisretinoids, originating from all-trans retinal substrate -A photometabolite of visual pigment cofactor 11-cis-retinal (responsible for photon capturing), are endowed with cytotoxic and complement-Activating potential which increases upon illumination and oxidation. This survey deals with oxidative stress, PUFAs (especially DHA) peroxidation products of carboxyalkylpyrrole type and bisretinoids as potential inducers of the CNS pathology. A focus is put on vision-threatening disease, i.e., age-related macular degeneration (AMD), as an example of the CNS disorder whose pathogenesis has strong background in both oxidative stress and lipid peroxidation products. Copyright © 2013 by Institute of Pharmacology.

Agency: European Commission | Branch: H2020 | Program: CSA | Phase: INFRADEV-03-2016-2017 | Award Amount: 3.88M | Year: 2017

The objectives of the IDEAAL Project are to explore all possibilities to develop GANIL infrastructure, with its new ESFRI SPIRAL2 facility, in order to ensure its long-term sustainability as one of the premiere European research institutes for nuclear physics, interdisciplinary sciences and related applications. The first objective of the IDEAAL Project is to enlarge the present GANIL membership to include academic institutions and private funding partners. This enlargement goes hand-in-hand with a reinforcement of the involvement of the current institutional funders and academic users of GANIL-SPIRAL2 in the decision-making process and management of the facility. The second objective of IDEAAL is to enhance the excellence of access to the infrastructure by optimizing support to the users, access policy, assessment on the cost of access to the facilities and to data, improvement of the performance capabilities as well as exchange and training of personnel with associated partners. Innovation is the third objective of IDEAAL. With the new facility SPIRAL2, it is essential to encourage industrial users of the uniqueness of this new machine for their research and applications and to allow them to develop new experimental tools at the existing GANIL facilities. Access provision dedicated to industrial users will greatly enhance their experience and increase their interest and trust in GANIL-SPIRAL2. In parallel, new ideas and topics for technology transfer will be clearly identified. The increase of innovation potential of GANIL will also be evaluated. These three objectives must be supported by a strong communication and outreach policy towards members and funding partners, users and the layman. This is the fourth objective of the project. Fulfilling all of these four objectives will allow a well-organized, highly efficient and sustainable development of the current GANIL structure.

Agency: European Commission | Branch: H2020 | Program: CSA | Phase: INFRAINNOV-02-2016 | Award Amount: 2.28M | Year: 2017

Development and construction of accelerator based scientific Research Infrastructures are going through a deep paradigm change because of the need for large scale Technological Infrastructures at the forefront of technology to master the key accelerator and magnet science and technology needed for several fields. Indeed, because of the high technological level and of the increased size and time scale of projects, development and construction require more and more sophisticated R&D platforms on key accelerator and magnet technologies, large-scale facilities for their assembly, integration and verification, large concentrations of dedicated skilled personnel and long term relationships between laboratories and industry. In response to those challenges, a few large platforms specialized in interdisciplinary technologies and for applications of direct benefit to society are emerging. The emerging Technological Infrastructure is aiming at creating an efficient integrated ecosystem among laboratories focussed on R&D, with a long term vision for the technological needs of future RIs and industry, including SME, motivated by the innovative environment and the market created by the realisation of the technological needs of several RIs. With a timeline of 30 months, involving 10 Consortium partners, the AMICI proposal will ensure that A) a stronger and optimised integration model between the large existing technological infrastructures is developed and agreed upon, B) that this integrated ecosystem is attracting industries and fostering innovation based on accelerator and SC magnets cutting-edge developments, C) that strategy and roadmaps are clearly defined and understood to strongly position European industries and SMEs on the market of the construction of new Research Infrastructures worldwide, and D) that potential societal applications are identified and disseminated to the relevant partners of this ecosystem.

Colmenares J.C.,Polish Academy of Sciences | Luque R.,University of Cordoba, Spain
Chemical Society Reviews | Year: 2014

Heterogeneous photocatalysis has become a comprehensively studied area of research during the past three decades due to its practical interest in applications including water-air depollution, cancer therapy, sterilization, artificial photosynthesis (CO2 photoreduction), anti-fogging surfaces, heat transfer and heat dissipation, anticorrosion, lithography, photochromism, solar chemicals production and many others. The utilization of solar irradiation to supply energy or to initiate chemical reactions is already an established idea. Excited electron-hole pairs are generated upon light irradiation of a wide-band gap semiconductor which can be applied to solar cells to generate electricity or in chemical processes to create/degrade specific compounds. While the field of heterogeneous photocatalysis for pollutant abatement and mineralisation of contaminants has been extensively investigated, a new research avenue related to the selective valorisation of residues has recently emerged as a promising alternative to utilise solar light for the production of valuable chemicals and fuels. This tutorial review will focus on the potential and applications of solid photonanocatalysts for the selective transformation of biomass-derived substrates. This journal is © The Royal Society of Chemistry.

Szumna A.,Polish Academy of Sciences
Chemical Society Reviews | Year: 2010

This tutorial review covers the recent development in the synthesis and application of molecules and finite assemblies that are chiral owing to their curvature. A modified definition of inherent chirality is provided. Various classes of chiral concave molecules are presented including salphen complexes, cyclic amides, derivatives of sumanene, trioxatricornan or subphthalocyanine, cyclotriveratrylenes, homooxacalix[3]arenes, calixarenes, resorcinarenes, phthalocyanines, corannulenes and cavitands. Some of these bowl shaped compounds exhibit high inversion barriers, comparable with the stability of classical carbon chirality centres, while the others (e.g. hydrogen bonded assemblies) can only be detected by NMR. This review is focused on practical aspects of synthesis, resolution and applications in chiral recognition and asymmetric synthesis. © 2010 The Royal Society of Chemistry.

Makosza M.,Polish Academy of Sciences
Chemical Society Reviews | Year: 2010

The aim of this tutorial review is to present two main messages. First, addition of nucleophilic agents to electron-deficient arenes proceeds faster in positions occupied by hydrogen than in those, equally activated, occupied by halogens or other nucleofugal groups. Thanks to numerous ways of further, fast conversion of the produced σH adducts into products of nucleophilic substitution of hydrogen, this is the main primary reaction between nucleophiles and electron-deficient arenes. Conventional nucleophilic substitution of halogen, SNAr reaction, is a secondary process that takes place when ways for fast further conversion of σH adducts are not available. The second message is that nucleophilic substitution of hydrogen is an efficient tool in organic synthesis. In order to stress the preference for nucleophilic substitution of hydrogen, halonitroarenes are chosen as examples of reacting electron-deficient arenes, but it is obvious that the presence of halogen is not necessary for substitution of hydrogen. © 2010 The Royal Society of Chemistry.

Loading Polish Academy of Sciences collaborators
Loading Polish Academy of Sciences collaborators