Prague, Czech Republic
Prague, Czech Republic

Charles University in Prague is the oldest and largest university in the Czech Republic. Founded in 1348, it was the first university in Central Europe, east of France and north of the Alps. It is one of the oldest universities in Europe in continuous operation and ranks in the upper 1.5 percent of the world’s best universities.Its seal shows its protector Emperor Charles IV, with his coats of arms as King of the Romans and King of Bohemia, kneeling in front of St. Wenceslas, the patron saint of Bohemia. It is surrounded by the inscription, Sigillum Universitatis Scolarium Studii Pragensis . Wikipedia.

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As magnetism is the footprint of the interactive behaviour of electrons, studying it on the atomic level informs us about the collective electronic behaviour in the atomic environment. This can explain macroscopically observed electronic properties, like the temperature dependence of the conductivity. On the atomic level, magnetic ions are closely packed and thus mutually influence each other, resulting in the adoption of a common magnetic order to minimise their energy balance. A slight perturbation leads to a spin wave, whereby an oscillation of one magnetic moment around its central axis induces oscillating perturbations with a slight phase shift on the atomic neighbours. Spin waves are routinely observed in ordered magnetic materials by inelastic neutron scattering (INS) on spectrometers at the Institut Laue-Langevin (ILL). The magnetic moment is characterised by its spin number. The larger the spin number, the more appropriate it is to compare the atomic magnetic moment with a classical magnet. Lowering the spin means accentuating its quantum properties; exploring the transition into the quantum world, which is fundamentally different from the daily, macroscopic world, is one of the most exciting challenges in solid state physics. The most cited example is the spin -1/2 moments placed in the corner of an equidistant triangle. Due to its quantum nature, one spin can only point upwards or downwards with respect to its local axis. A magnetic exchange between the spin moments, that is antiferromagnetic in nature, forces them to align antiparallel to each other. As a quantum magnet cannot order, rather than adopting one ground state, several states are equally likely (6 in the case of the triangle), and the spins are in a super-positioned state pointing in several directions at once. Combining equidistant triangles leads to a two-dimensional network of spins. Its ground state, i.e. the spin arrangement with the lowest possible energy cost, has challenged theorists for decades. In 1973, noble laureate P.W. Anderson proposed a so-called 'quantum spin liquid state,' which is conceptually completely different to ordered magnetic phases. Anderson argued that for a triangular system, it is energetically more favourable for spins to organise into bonds. In these valence bonds, electrons are quantum mechanically 'entangled,' a purely quantum mechanical state. A superposition of a manifold of bond pattern exists in parallel and bonds fluctuate due to a quantum mechanical principle, which imposes zero point motions on the particles. This state is called a Resonant Valence Bond (RVB) state. Neutron scattering provides experimental proof for the RVB state Here at ILL, two cold three-axis spectrometers, IN14 and IN12, contributed over decades to the discovery and unravelling of magnetic correlations in classical and non-conventional superconductors, multiferroic crystals and a wide range of low-dimensional, frustrated and quantum magnetic systems. As both instruments dated from the 1980s, they were in need of a complete refurbishment to be able to continue contributing to the scientific progress in these fields. The new IN12 spectrometer's relocation and refurbishment was completed in 2012, and by the end of 2014, the IN14 spectrometer was replaced by its successor, ThALES. ThALES, Three-Axis instrument for Low Energy Spectroscopy, is a next generation cold neutron three-axis spectrometer that builds on the strengths of its predecessor, IN14, but uses state-of-the-art neutron optics. The ThALES project is a collaboration between ILL and Charles University, Prague, and is financed by the Czech Ministry of Science and Education. After replacing the IN14, ThALES became the new reference for cold single crystal neutron spectroscopy at a steady state neutron source like the ILL reactor. ThALES has been fully optimised to address the physics of highly correlated electron systems and scientific problems in the field of quantum magnetism. Moreover, the flexibility of the spectrometer has been enhanced through the implementation of various optical elements. The key aims of ThALES are: ThALES was used to carry out INS measurements in a recent study conducted by a collaboration of scientists, including ILL's Martin Boehm, current co-ordinator of the EU-funded neutron network SINE2020. The study published in Nature, titled 'Evidence for a spinon Fermi surface in a triangular lattice quantum-spin-liquid candidate,' argued that the triangular-lattice antiferromagnet YbMgGaO4 has the long sought quantum spin liquid RVB ground state. This study was the first to use neutron scattering as a means of providing experimental proof for the RVB state. The experimental effort to discover the RVB ground state has considerably increased since P.W. Anderson suggested that it might explain the phenomenon of superconductivity in a class of materials that show particularly high transition temperatures between a normal conducting and superconducting state. However, providing experimental proof for the existence of the RVB state is very challenging, because while a magnetically ordered system has a clear experimental response, the RVB state is characterised by the absence of a measurable quantity. Due to the lack of a measurable quantity, the experimental approach of this study, using ThALES, selected indirect experimental proof by deliberately exciting the ground state with neutrons and measuring the dynamic response. According to theoretical expectations, the excited spin liquid behaves 'exotically,' meaning the excited state is explained by spinons with very unusual properties. Spinons can rearrange the distribution of valence bonds and travel throughout the triangular plane with a minimum amount of energy. In a scattering process between the neutron and the spin liquid, the law of conservation of total momentum imposes the creation of two spin-1/2 spinons in the liquid. This pair of spinons travel in opposite directions with a total amount of energy equalling the loss of neutron energy in the scattering process. Using the ThALES spectrometer, it is possible to trace the direction and energies of the spinons by measuring the direction and energy of the neutron that created the spinon pair. In this way, this study traced a complete dynamical landscape of the spin quantum liquid in the triangular plane, and compared the measurements with theoretical predictions, which gave strong evidence for the existence of the spin liquid phase in YbMgGaO4. This research is important as a quantum spin liquid state of matter is potentially relevant for applications of quantum information. Moreover, experimental identification of a quantum spin liquid state contributes greatly to our understanding of quantum matter. Explore further: Novel state of matter: Observation of a quantum spin liquid More information: Yao Shen et al. Evidence for a spinon Fermi surface in a triangular-lattice quantum-spin-liquid candidate, Nature (2016). DOI: 10.1038/nature20614


Patent
Charles University | Date: 2017-05-17

A testing thermo-chamber, which is equipped with a bearing (1), heat exchanger (2) and a tension bar (4) for attaching the tested object. The inner room of the bearing ( 1 ) is equipped with a temperature sensor ( 3 ), the heat exchanger (2) being connected to more heating and cooling circuits (6) with multiport control valves (9), interconnected to thermostats (10) and by-passing branches (11), temperature sensor (3) is connected to the temperature regulator (12 ) further connected to thermostats (10) and a control unit (13) interconnected with multiport control valves (9).


News Article | April 17, 2017
Site: www.scientificamerican.com

People with Parkinson’s disease may show hints of motor difficulty years before an official diagnosis, but current methods for detecting early symptoms require clinic visits and highly trained personnel. Three recent studies, however, suggest that diagnosis could be as simple as walking, talking and typing. Tests of activities such as these might eventually enable early intervention, which will be crucial for halting progression of the neurodegenerative condition if a cure becomes available. The findings are exciting, says neurologist Zoltan Mari of Johns Hopkins University. But he cautions that larger studies will be necessary to ensure that these techniques are ready for wider use. Walking: Data from wearable sensors attached to 93 Parkinson’s patients and 73 healthy controls revealed distinctive walking patterns: factors such as step distance and heel force helped to differentiate between the two groups with 87 percent accuracy, according to an analysis by Shyam Perumal and Ravi Sankar of the University of South Florida. Talking: In a study by Jan Rusz of Czech Technical University and Charles University, both in Prague, and his colleagues, participants read a list of words aloud, and each made a 90-second recording during which they described their current interests. Fifty of the participants were at high risk for developing Parkinson’s, but only 23 had begun to show symptoms. Simple acoustic features of the short speech samples—including slower speed of talking and longer duration of pauses than healthy controls—pinpointed the symptomatic participants with 70 percent accuracy. Typing: People with and without Parkinson’s were asked to listen to a folktale and transcribe it by typing. The two groups were matched for age and overall typing speed and excluded people with dementia. Luca Giancardo of the Massachusetts Institute of Technology and his colleagues successfully discriminated between the groups solely by analyzing key hold times (the time required to press and release a key). Their analysis performed comparably or better than motor tests currently used in clinical settings.


ATLANTA & LA PLATA, Md.--(BUSINESS WIRE)--University of Maryland Charles Regional Medical Center announces the opening of a new outpatient imaging center in partnership with two other organizations. University of Maryland Charles Regional Imaging (UM CRI), located at 5 North La Plata Court, Suite 104 in La Plata, Maryland, offers state-of-the art imaging services, including 3T MRI, Arthrography, CT, Ultrasound, X-Ray, Mammography and Bone Densitometry. UM CRI provides patients and referring physicians with high-quality imaging services and is staffed by expert board-certified and fellowship-trained radiologists from University of Maryland School of Medicine and certified technologists who are dedicated to delivering thorough, accurate and prompt reports as well as high-quality compassionate patient care. The center offers flexible scheduling featuring same-day or next-day appointments (insurance permitting) and 24-hour report turnaround for referring physicians. The University of Maryland Charles Regional Medical Center (UM CRMC), University of Maryland Diagnostic Imaging Specialists, PA (DISPA), and MedQuest Associates, Inc. have entered into a joint venture to develop and operate the full-modality outpatient diagnostic imaging center. DISPA represents the outpatient practices of the University of Maryland Department of Diagnostic Radiology and Nuclear Medicine and provides academic subspecialty radiologists (covering multiple clinical subspecialties) to interpret the studies performed at the center. MedQuest Associates, a leading national provider of imaging management services for health systems, will manage the day-to-day operations of the center. “Our community is growing,” said Noel Cervino, President and CEO of UM CRMC, “and the need for access to the highest quality medical options close to home has never been greater. We are the only center in the area to bring partners like DISPA, who are University of Maryland sub-specialty, faculty radiologists, together with MedQuest, a national leader in imaging management.” Mr. Cervino added, “As a community hospital, we are committed to bringing the best medicine to the citizens of Charles County and the surrounding areas.” Elias R. Melhem, MD, Chairman of the Department of Diagnostic Radiology and Nuclear Medicine at University of Maryland School of Medicine, added, “Working with our partners at UM Charles Regional Medical Center and MedQuest Associates to plan and build the imaging center has been such an enjoyable experience. There is a positive energy around this joint venture because we are aligned in our goals to provide convenient, high quality, state-of-the-art and cost effective care to our patients, and we look forward to opening the center and taking care of our patients.” Bruce Elder, CEO of MedQuest Associates, added, “We are thrilled to be partnering with two organizations that are committed to providing the highest quality care to patients in southern Maryland. Together with UM Charles Regional Medical Center and University of Maryland Diagnostic Imaging Specialists, we have the capabilities to provide patients and physicians with an outstanding combination of technology, convenience, clinical expertise and cost-effectiveness.” For more information, visit www.charlesregionalimaging.com or call 301-539-0345. UM Charles Regional Medical Center is a member of the University of Maryland Medical System and serves as regional, not-for-profit, integrated health system serving Charles County and the surrounding areas of southern Maryland. Our mission is to always provide excellent patient care as measured by the population’s health, clinical outcomes, patient satisfaction and cost effectiveness. UM Charles Regional Medical Center will remain the premier place to receive care and the premier place to provide care. For more information, visit www.charlesregional.org. DISPA represents the outpatient practices of the University of Maryland Department of Diagnostic Radiology and Nuclear Medicine and provides comprehensive evaluation, diagnosis and treatment of a wide range of specialized health conditions through advanced technology and non-invasive diagnostic tools. Our team of experts is made up of more than 70 clinical and research faculty, including some of the nation’s most accomplished physician leaders in radiology. We thoughtfully plan and implement state-of-the-art imaging equipment and technology to offer the best possible patient care. For more information, visit www.umfpi.org/dispa. MedQuest is a leading owner, operator and manager of diagnostic imaging facilities and hospital radiology services, with a network of nearly 50 imaging centers and 14 acute care hospital radiology departments under management. As one of the nation’s most experienced outpatient imaging partners, MedQuest also provides comprehensive services, including outpatient imaging management and joint venture (JV), referring physician engagement and service line performance consulting. Serving health systems, hospitals and imaging centers nationwide, MedQuest draws upon decades of operational experience and industry knowledge to deliver comprehensive guidance and solutions that increase revenue and optimize operations, while improving quality and the patient experience. MedQuest’s industry-leading proprietary systems and processes create an unrivaled value proposition for its partners. Learn more at www.mqradiology.com.


Norena A.J.,Charles University
Neuroscience and Biobehavioral Reviews | Year: 2011

The purpose of the current review is to propose a model highlighting the putative connections between hearing loss and the phantom perception of tinnitus (tinnitus being accompanied by hearing loss in the majority, if not all, subjects). Sensory deprivation is followed by dramatic functional and structural changes in the auditory system. Notably, while cochlear injuries are accompanied by a reduced activity in the cochlear nerve, neural activity is increased at virtually all levels in the central auditory system. We suggest that this central hyperactivity could result from a central gain increase; the general purpose of this gain modulation being to adapt neural sensitivity to the reduced sensory inputs, preserving a stable mean firing and neural coding efficiency. However, maintaining neural homeostasis at all costs, in the event of an auditory system sensory deprivation, could be done at the price of amplifying " neural noise" due to the overall increase of gain (or sensitivity), ultimately resulting in the generation of tinnitus. The clinical implications of this model are also presented. © 2010 Elsevier Ltd.


Fisar Z.,Charles University
Progress in Neuro-Psychopharmacology and Biological Psychiatry | Year: 2016

Progress in understanding the role of monoamine neurotransmission in pathophysiology of neuropsychiatric disorders was made after the discovery of the mechanisms of action of psychoactive drugs, including monoamine oxidase (MAO) inhibitors. The increase in monoamine neurotransmitter availability, decrease in hydrogen peroxide production, and neuroprotective effects evoked by MAO inhibitors represent an important approach in the development of new drugs for the treatment of mental disorders and neurodegenerative diseases. New drugs are synthesized by acting as multitarget-directed ligands, with MAO, acetylcholinesterase, and iron chelation as targets. Basic information is summarized in this paper about the drug-induced regulation of monoaminergic systems in the brain, with a focus on MAO inhibition. Desirable effects of MAO inhibition include increased availability of monoamine neurotransmitters, decreased oxidative stress, decreased formation of neurotoxins, induction of pro-survival genes and antiapoptotic factors, and improved mitochondrial functions. © 2016 Elsevier Inc.


Roithova J.,Charles University
Chemical Society Reviews | Year: 2012

In the last decade, we have experienced massive progress in spectroscopic methods for mass-selected ions. The aim of this tutorial review is to present action spectroscopy as a powerful tool for the investigation of ionic reaction intermediates. Examples span from ultraviolet and infrared photodissociation spectroscopy of model reaction intermediates to applications of infrared multiphoton dissociation spectroscopy (IRMPD) to intermediates directly sampled from reaction mixtures. The first example of double resonance IR-UV spectroscopy of model intermediates in an organometallic reaction is also mentioned. © 2012 The Royal Society of Chemistry.


Stepnika P.,Charles University
Chemical Society Reviews | Year: 2012

Compounds combining phosphine and carboxamide moieties in their molecules have developed virtually unnoticed into a specific class of highly structurally versatile and tuneable donor molecules finding manifold use in various fields, particularly in coordination chemistry, biomedical sciences and in catalysis. In the latter field, some phosphinoamides became the real privileged ligands and an indispensable part of a standard toolbox for synthetic chemists. This critical review aims to give an overview of the multifaceted chemistry of such compounds, paying attention to both the fundamentals and recent developments in this continuously expanding field. © 2012 The Royal Society of Chemistry.


Flegr J.,Charles University
Trends in Parasitology | Year: 2013

For a long time, a latent toxoplasmosis, the lifelong presence of dormant stages of Toxoplasma in various tissues, including the brain, was considered harmless for immunocompetent persons. Within the past 10 years, however, many independent studies have shown that this parasitic disease, with a worldwide prevalence of about 30%, could be indirectly responsible for hundreds of thousands of deaths due to its effects on the rate of traffic and workplace accidents, and also suicides. Moreover, latent toxoplasmosis is probably one of the most important risk factors for schizophrenia. At least some of these effects, possibly mediated by increased dopamine and decreased tryptophan, are products of manipulation activity by Toxoplasma aiming to increase the probability of transmission from intermediate to definitive host through predation. © 2013.


The parasitic protozoan Toxoplasma gondii infects about one-third of the population of developed countries. The life-long presence of dormant stages of this parasite in the brain and muscular tissues of infected humans is usually considered asymptomatic from the clinical point of view. In the past 20?years, research performed mostly on military personnel, university students, pregnant women and blood donors has shown that this ?asymptomatic' disease has a large influence on various aspects of human life. Toxoplasma-infected subjects differ from uninfected controls in the personality profile estimated with two versions of Cattell's 16PF, Cloninger's TCI and Big Five questionnaires. Most of these differences increase with the length of time since the onset of infection, suggesting that Toxoplasma influences human personality rather than human personality influencing the probability of infection. Toxoplasmosis increases the reaction time of infected subjects, which can explain the increased probability of traffic accidents in infected subjects reported in three retrospective and one very large prospective case-control study. Latent toxoplasmosis is associated with immunosuppression, which might explain the increased probability of giving birth to a boy in Toxoplasma-infected women and also the extremely high prevalence of toxoplasmosis in mothers of children with Down syndrome. Toxoplasma-infected male students are about 3?cm taller than Toxoplasma-free subjects and their faces are rated by women as more masculine and dominant. These differences may be caused by an increased concentration of testosterone. Toxoplasma also appears to be involved in the initiation of more severe forms of schizophrenia. At least 40 studies confirmed an increased prevalence of toxoplasmosis among schizophrenic patients. Toxoplasma-infected schizophrenic patients differ from Toxoplasma-free schizophrenic patients by brain anatomy and by a higher intensity of the positive symptoms of the disease. Finally, five independent studies performed in blood donors, pregnant women and military personnel showed that RhD blood group positivity, especially in RhD heterozygotes, protects infected subjects against various effects of latent toxoplasmosis, such as the prolongation of reaction times, an increased risk of traffic accidents and excessive pregnancy weight gain. The modern human is not a natural host of Toxoplasma. Therefore, it can only be speculated which of the observed effects of latent toxoplasmosis are the result of the manipulation activity of the Toxoplasma aimed to increase the probability of its transmission from a natural intermediate to the definitive host by predation, and which are just side effects of chronic infection. © 2013 Published by The Company of Biologists Ltd.

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