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Studnička J, Němčanský J, Vysloužilová D, Ernest J, Němec P. Diabetic Retinopathy – Diagnostics and Treatment Guidelines. Cesk Slov Oftalmol 2023; 79:238-247. [PMID: 37993272 DOI: 10.31348/2023/28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
Diabetic retinopathy is one of the most common complications of diabetes mellitus and represents a serious health, social and economic problem. With the expected increase in the number of patients with diabetes, it is becoming the leading cause of severe vision loss in the working-age population. The presented guidelines summarize the current knowledge about this disease in order to standardize and update the procedures for the diagnosis, classification and treatment of diabetic retinopathy.
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Němčanský J, Studnička J, Vysloužilová D, Ernest J, Němec P. Diabetic Retinopathy and Diabetic Macular Edema - Screening. Cesk Slov Oftalmol 2023; 79:250-255. [PMID: 37993273 DOI: 10.31348/2023/29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
Diabetic retinopathy (DR) and diabetic macular edema (DME) are leading causes of severe visual loss in the working population. Therefore, both DR and DME have a significant socioeconomic and health impact, which taking into account the epidemiologic predictions is expected to increase. A crucial role in the management of DR and DME (not only for individuals, but also for the population) is played by an adequate screening program. This is based on the structure and organization of the healthcare system, the latest scientific developments in diagnostics (imaging) as well as technological advancements in computing (artificial intelligence, telemedicine) and their practical use. The recommendation presented by World Health Organization is also important. This paper evaluates all these factors, including evidence-based medicine reports and experience from existing DR and DME screening programs in comparable countries. Based on an evaluation of these parameters, recommended guidelines have been formulated for screening for DR and DME in the Czech Republic, including linkage to the Czech National Screening Center and the organization of the healthcare system.
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Janda T, Ostatnický T, Němec P, Schmoranzerová E, Campion R, Hills V, Novák V, Šobáň Z, Wunderlich J. Ultrashort spin-orbit torque generated by femtosecond laser pulses. Sci Rep 2022; 12:21550. [PMID: 36513672 DOI: 10.1038/s41598-022-24808-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 11/18/2022] [Indexed: 12/15/2022] Open
Abstract
To realize the very objective of spintronics, namely the development of ultra-high frequency and energy-efficient electronic devices, an ultrafast and scalable approach to switch magnetic bits is required. Magnetization switching with spin currents generated by the spin-orbit interaction at ferromagnetic/non-magnetic interfaces is one of such scalable approaches, where the ultimate switching speed is limited by the Larmor precession frequency. Understanding the magnetization precession dynamics induced by spin-orbit torques (SOTs) is therefore of great importance. Here we demonstrate generation of ultrashort SOT pulses that excite Larmor precession at an epitaxial Fe/GaAs interface by converting femtosecond laser pulses into high-amplitude current pulses in an electrically biased p-i-n photodiode. We control the polarity, amplitude, and duration of the current pulses and, most importantly, also their propagation direction with respect to the crystal orientation. The SOT origin of the excited Larmor precession was revealed by a detailed analysis of the precession phase and amplitude at different experimental conditions.
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Affiliation(s)
- T Janda
- Institute for Experimental and Applied Physics, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany. .,Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2, Czech Republic.
| | - T Ostatnický
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2, Czech Republic
| | - P Němec
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2, Czech Republic
| | - E Schmoranzerová
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2, Czech Republic
| | - R Campion
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - V Hills
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - V Novák
- Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 00, Prague 6, Czech Republic
| | - Z Šobáň
- Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 00, Prague 6, Czech Republic
| | - J Wunderlich
- Institute for Experimental and Applied Physics, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany.,Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 00, Prague 6, Czech Republic
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Vydláková J, Tesař J, Krátký V, Šín M, Němec P. LATERAL TARSAL STRIP TECHNIQUE IN CORRECTION OF EYELID ECTROPION AND ENTROPION. Cesk Slov Oftalmol 2021; 77:73-78. [PMID: 33985336 DOI: 10.31348/2021/10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
BACKGROUND Ectropion and entropion are eyelid malpositions associated with a number of unpleasant symptoms. One of several surgical methods that can correct these problems is referred to as the lateral tarsal strip technique. In this paper, we evaluate the postoperative results and quality of this technique. We also examine the complications associated with this surgical method. METHODS The study took place from April 2018 to April 2020 at the Military University Hospital in Prague. The operation was performed by two surgeons. The study included 43 eyes of 33 patients (17 women and 16 men), average age was 79 years. Before the operation, 23 eyes were affected by ectropion and 20 eyes affected by entropion, 35 of the 43 were cases of involutional origin. The study does not include patients who underwent other surgical techniques. RESULTS There were no perioperative or postoperative complications in the entropion surgery group. Successful correction was achieved, and adverse symptoms disappeared in 91.3% of cases. Correct position of the eyelid was not achieved in two cases. For patients with ectropion, surgical correction was successful in 95% of cases. Ectropion persisted after surgery only in one patient. CONCLUSION The lateral tarsal strip technique is a safe, reliable and highly effective surgical technique. Correction of eyelid malposition was achieved in more than 90% of cases. The vast majority of patients were satisfied and reported relief from preoperative symptoms.
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Tesař J, Šín M, Němec P, Studnička J. DIAGNOSIS THAT MIMIC PACHYCHOROID DISEASES OF MACULA - CASE REPORTS. Cesk Slov Oftalmol 2021; 77:36-44. [PMID: 33740866 DOI: 10.31348/2021/4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Pachychoroid disease of retina is a spectrum of diseases manifested by thickening and hyperperfusion of the choroid with changes in the sensory part of the retina. The main unit of this group is central serous chorioretinopathy (CSC). In practice, we often encounter other conditions, which are manifested by thickening of the choroid and changes in the retina, but they cannot be classified as pachychoroid diseases. The aim of this study is to point out on a series of 3 case reports the difficulties in the differential diagnosis of retinal diseases in which we find thickening of the choroid. Case report 1: 42-year-old patient treated for central serous chorioretinopathy. After optical coherence tomography (OCT), fluorescence angiography (FAG) and indocyanine green angiography (ICG) the diagnosis was changed to choroidal hemangioma and he was treated with photodynamic therapy (PDT) which led to a reduction of the hemangioma. Case report 2: A 30-year-old patient treated for ankylosing spondylitis comes for visual impairment in the left eye. On OCT the condition resembled chronic CSC. The patient suffered from a febrile exanthema a few days ago. Serological testing for coxsackievirus was positive and the diagnosis was changed to acute chorioretinitis in coxsackievirus infection. Oral treatment with prednisone was successful. Case report 3: A 46-year-old patient was treated conservatively for CSC. After FAG and ICG, a solitary dilated choroidal vessel was found in the area of the papillomacular bundle with leakage under the sensory epithelium which was diagnosed as choroidal macrovessel. We performed PDT with a very good anatomical effect. Conclusion: Precise differentiation of these mentioned diseases from pachychoroid retinal diseases was essential in choosing the appropriate therapy. The use of all modern imaging methods of the retina and choroid plays a key role in determining the diagnosis. Key words: pachychoroid disease, central serous chorioretinopathy, choroidal hemangioma, chorioretinitis, coxsackievirus, choroidal macrovessel.
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Kufová Z, Sevcikova T, Growkova K, Vojta P, Filipová J, Adam Z, Pour L, Penka M, Rysava R, Němec P, Brozova L, Vychytilova P, Jurczyszyn A, Grosicki S, Barchnicka A, Hajdúch M, Simicek M, Hájek R. Biomarkers in Immunoglobulin Light Chain Amyloidosis. Klin Onkol 2019; 30:60-67. [PMID: 28903572 DOI: 10.14735/amko20172s60] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Immunoglobulin light chain amyloidosis (AL amyloidosis - ALA) is a monoclonal gammopathy characterized by presence of aberrant plasma cells producing amyloidogenic immunoglobulin light chains. This leads to formation of amyloid fibrils in various organs and tissues, mainly in heart and kidney, and causes their dysfunction. As amyloid depositing in target organs is irreversible, there is a big effort to identify biomarker that could help to distinguish ALA from other monoclonal gammopathies in the early stages of disease, when amyloid deposits are not fatal yet. High throughput technologies bring new opportunities to modern cancer research as they enable to study disease within its complexity. Sophisticated methods such as next generation sequencing, gene expression profiling and circulating microRNA profiling are new approaches to study aberrant plasma cells from patients with light chain amyloidosis and related diseases. While generally known mutation in multiple myeloma patients (KRAS, NRAS, MYC, TP53) were not found in ALA, number of mutated genes is comparable. Transcriptome of ALA patients proves to be more similar to monoclonal gammopathy of undetermined significance patients, moreover level of circulating microRNA, that are known to correlate with heart damage, is increased in ALA patients, where heart damage in ALA typical symptom.Key words: amyloidosis - plasma cell - genome - transcriptome - microRNA.
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Janda T, Nádvorník L, Kuchařík J, Butkovičová D, Schmoranzerová E, Trojánek F, Němec P. Voigt effect-based wide-field magneto-optical microscope integrated in a pump-probe experimental setup. Rev Sci Instrum 2018; 89:073703. [PMID: 30068140 DOI: 10.1063/1.5023183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this work, we describe an experimental setup for a spatially resolved pump-probe experiment with an integrated wide-field magneto-optical (MO) microscope. The MO microscope can be used to study ferromagnetic materials with both perpendicular-to-plane and in-plane magnetic anisotropy via polar Kerr and Voigt effects, respectively. The functionality of the Voigt effect-based microscope was tested using an in-plane magnetized ferromagnetic semiconductor (Ga,Mn)As. It was revealed that the presence of mechanical defects in the (Ga,Mn)As epilayer alters significantly the magnetic anisotropy in their proximity. The importance of MO experiments with simultaneous temporal and spatial resolutions was demonstrated using a (Ga,Mn)As sample attached to a piezoelectric transducer, which produces a voltage-controlled strain. We observed a considerably different behavior in different parts of the sample that enabled us to identify sample parts where the epilayer magnetic anisotropy was significantly modified by the presence of the piezoelectric transducer and where it was not. Finally, we discuss the possible applicability of our experimental setup for the research of compensated antiferromagnets, where only MO effects even in magnetic moments are present.
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Affiliation(s)
- T Janda
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | - L Nádvorník
- Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 53 Prague 6, Czech Republic
| | - J Kuchařík
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | - D Butkovičová
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | - E Schmoranzerová
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | - F Trojánek
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | - P Němec
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
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Wadley P, Edmonds KW, Shahedkhah MR, Campion RP, Gallagher BL, Železný J, Kuneš J, Novák V, Jungwirth T, Saidl V, Němec P, Maccherozzi F, Dhesi SS. Control of antiferromagnetic spin axis orientation in bilayer Fe/CuMnAs films. Sci Rep 2017; 7:11147. [PMID: 28894219 PMCID: PMC5593844 DOI: 10.1038/s41598-017-11653-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 08/25/2017] [Indexed: 11/22/2022] Open
Abstract
Using x-ray magnetic circular and linear dichroism techniques, we demonstrate a collinear exchange coupling between an epitaxial antiferromagnet, tetragonal CuMnAs, and an Fe surface layer. A small uncompensated Mn magnetic moment is observed which is antiparallel to the Fe magnetization. The staggered magnetization of the 5 nm thick CuMnAs layer is rotatable under small magnetic fields, due to the interlayer exchange coupling. This allows us to obtain the x-ray magnetic linear dichroism spectra for different crystalline orientations of CuMnAs in the (001) plane. This is a key parameter for enabling the understanding of domain structures in CuMnAs imaged using x-ray magnetic linear dichroism microscopy techniques.
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Affiliation(s)
- P Wadley
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom.
| | - K W Edmonds
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - M R Shahedkhah
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - R P Campion
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - B L Gallagher
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - J Železný
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00, Praha 6, Czech Republic.,Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - J Kuneš
- Institute of Physics, Czech Academy of Sciences, Na Slovance 1999/2, 182 21, Praha 8, Czech Republic.,Institute of Solid State Physics, TU Wien, Wiedner Hauptstr. 8, 1040, Wien, Austria
| | - V Novák
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00, Praha 6, Czech Republic
| | - T Jungwirth
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom.,Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00, Praha 6, Czech Republic
| | - V Saidl
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 162 00, Praha 6, Czech Republic.,Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Praha 2, Czech Republic
| | - P Němec
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Praha 2, Czech Republic
| | - F Maccherozzi
- Diamond Light Source, Chilton, Didcot, Oxfordshire, OX11 0DE, United Kingdom
| | - S S Dhesi
- Diamond Light Source, Chilton, Didcot, Oxfordshire, OX11 0DE, United Kingdom
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9
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Baudet E, Gutierrez-Arroyo A, Baillieul M, Charrier J, Němec P, Bodiou L, Lemaitre J, Rinnert E, Michel K, Bureau B, Adam JL, Nazabal V. Development of an evanescent optical integrated sensor in the mid-infrared for detection of pollution in groundwater or seawater. ACTA ACUST UNITED AC 2017. [DOI: 10.1080/20550308.2017.1338211] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- E. Baudet
- Institut des Sciences Chimiques de Rennes, UMR-CNRS 6226, Equipe Verres et Céramiques, Université de Rennes 1, Rennes, France
| | | | - M. Baillieul
- Institut des Sciences Chimiques de Rennes, UMR-CNRS 6226, Equipe Verres et Céramiques, Université de Rennes 1, Rennes, France
| | - J. Charrier
- FOTON -UMR-CNRS 6082, ENSSAT, Lannion Cedex, France
| | - P. Němec
- Faculty of Chemical Technology, Department of Graphic Arts and Photophysics, University of Pardubice, Pardubice, Czech Republic
| | - L. Bodiou
- FOTON -UMR-CNRS 6082, ENSSAT, Lannion Cedex, France
| | - J. Lemaitre
- FOTON -UMR-CNRS 6082, ENSSAT, Lannion Cedex, France
| | - E. Rinnert
- Laboratoire Détection, Capteurs et Mesures, Dpt. Recherches et Développements Technologiques, IFREMER, Plouzané, France
| | - K. Michel
- BRGM, Direction Eau, Environnement et Ecotechnologies, Unité Bio-Géochimie environnementale et qualité de l’Eau, Orléans, France
| | - B. Bureau
- Institut des Sciences Chimiques de Rennes, UMR-CNRS 6226, Equipe Verres et Céramiques, Université de Rennes 1, Rennes, France
| | - J. L. Adam
- Institut des Sciences Chimiques de Rennes, UMR-CNRS 6226, Equipe Verres et Céramiques, Université de Rennes 1, Rennes, France
| | - V. Nazabal
- Institut des Sciences Chimiques de Rennes, UMR-CNRS 6226, Equipe Verres et Céramiques, Université de Rennes 1, Rennes, France
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10
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Janda T, Roy PE, Otxoa RM, Šobáň Z, Ramsay A, Irvine AC, Trojanek F, Surýnek M, Campion RP, Gallagher BL, Němec P, Jungwirth T, Wunderlich J. Inertial displacement of a domain wall excited by ultra-short circularly polarized laser pulses. Nat Commun 2017; 8:15226. [PMID: 28513588 PMCID: PMC5442316 DOI: 10.1038/ncomms15226] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 03/10/2017] [Indexed: 11/09/2022] Open
Abstract
Domain wall motion driven by ultra-short laser pulses is a pre-requisite for envisaged low-power spintronics combining storage of information in magnetoelectronic devices with high speed and long distance transmission of information encoded in circularly polarized light. Here we demonstrate the conversion of the circular polarization of incident femtosecond laser pulses into inertial displacement of a domain wall in a ferromagnetic semiconductor. In our study, we combine electrical measurements and magneto-optical imaging of the domain wall displacement with micromagnetic simulations. The optical spin-transfer torque acts over a picosecond recombination time of the spin-polarized photo-carriers that only leads to a deformation of the initial domain wall structure. We show that subsequent depinning and micrometre-distance displacement without an applied magnetic field or any other external stimuli can only occur due to the inertia of the domain wall. Domain wall motion driven by ultra-short laser pulses has potential for storage of information in magnetoelectronic devices. Here the authors demonstrate the conversion of a circularly polarized femtosecond laser light into inertial displacement of a domain wall in a ferromagnetic semiconductor.
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Affiliation(s)
- T Janda
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic.,Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 00 Praha 6, Czech Republic
| | - P E Roy
- Hitachi Cambridge Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK
| | - R M Otxoa
- Hitachi Cambridge Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK
| | - Z Šobáň
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 00 Praha 6, Czech Republic
| | - A Ramsay
- Hitachi Cambridge Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK
| | - A C Irvine
- Microelectronics Research Center, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK
| | - F Trojanek
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | - M Surýnek
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | - R P Campion
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - B L Gallagher
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - P Němec
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | - T Jungwirth
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 00 Praha 6, Czech Republic.,School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - J Wunderlich
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 00 Praha 6, Czech Republic.,Hitachi Cambridge Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK
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Kriegner D, Výborný K, Olejník K, Reichlová H, Novák V, Marti X, Gazquez J, Saidl V, Němec P, Volobuev VV, Springholz G, Holý V, Jungwirth T. Multiple-stable anisotropic magnetoresistance memory in antiferromagnetic MnTe. Nat Commun 2016; 7:11623. [PMID: 27279433 PMCID: PMC4906165 DOI: 10.1038/ncomms11623] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 04/14/2016] [Indexed: 11/26/2022] Open
Abstract
Commercial magnetic memories rely on the bistability of ordered spins in ferromagnetic materials. Recently, experimental bistable memories have been realized using fully compensated antiferromagnetic metals. Here we demonstrate a multiple-stable memory device in epitaxial MnTe, an antiferromagnetic counterpart of common II–VI semiconductors. Favourable micromagnetic characteristics of MnTe allow us to demonstrate a smoothly varying zero-field antiferromagnetic anisotropic magnetoresistance (AMR) with a harmonic angular dependence on the writing magnetic field angle, analogous to ferromagnets. The continuously varying AMR provides means for the electrical read-out of multiple-stable antiferromagnetic memory states, which we set by heat-assisted magneto-recording and by changing the writing field direction. The multiple stability in our memory is ascribed to different distributions of domains with the Néel vector aligned along one of the three magnetic easy axes. The robustness against strong magnetic field perturbations combined with the multiple stability of the magnetic memory states are unique properties of antiferromagnets. Contrary to ferromagnets, antiferromagnets possess no net magnetic moment, which has limited their applicability as magnetic memory media. Here, the authors demonstrate a heat-assisted multiple-stable memory based on epitaxial thin films of antiferromagnet MnTe with three-fold symmetric anisotropy.
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Affiliation(s)
- D Kriegner
- Charles University in Prague, Ke Karlovu 3, Praha 2 121 16, Czech Republic
| | - K Výborný
- Institute of Physics, Academy of Science of the Czech Republic, Cukrovarnická 10, Praha 6 162 00, Czech Republic
| | - K Olejník
- Institute of Physics, Academy of Science of the Czech Republic, Cukrovarnická 10, Praha 6 162 00, Czech Republic
| | - H Reichlová
- Institute of Physics, Academy of Science of the Czech Republic, Cukrovarnická 10, Praha 6 162 00, Czech Republic
| | - V Novák
- Institute of Physics, Academy of Science of the Czech Republic, Cukrovarnická 10, Praha 6 162 00, Czech Republic
| | - X Marti
- Institute of Physics, Academy of Science of the Czech Republic, Cukrovarnická 10, Praha 6 162 00, Czech Republic
| | - J Gazquez
- Institut de Ciència de Materials de Barcelona ICMAB, Consejo Superior de Investigaciones Científicas CSIC, Campus UAB, Bellaterra, Catalonia 08193, Spain
| | - V Saidl
- Charles University in Prague, Ke Karlovu 3, Praha 2 121 16, Czech Republic
| | - P Němec
- Charles University in Prague, Ke Karlovu 3, Praha 2 121 16, Czech Republic
| | - V V Volobuev
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstraβe. 69, Linz 4040, Austria.,National Technical University, 'Kharkiv Polytechnic Institute', Frunze Str. 21, Kharkiv 61002, Ukraine
| | - G Springholz
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstraβe. 69, Linz 4040, Austria
| | - V Holý
- Charles University in Prague, Ke Karlovu 3, Praha 2 121 16, Czech Republic
| | - T Jungwirth
- Institute of Physics, Academy of Science of the Czech Republic, Cukrovarnická 10, Praha 6 162 00, Czech Republic.,School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
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12
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Bouška M, Pechev S, Simon Q, Boidin R, Nazabal V, Gutwirth J, Baudet E, Němec P. Pulsed laser deposited GeTe-rich GeTe-Sb2Te3 thin films. Sci Rep 2016; 6:26552. [PMID: 27199107 PMCID: PMC4873812 DOI: 10.1038/srep26552] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 05/03/2016] [Indexed: 12/02/2022] Open
Abstract
Pulsed laser deposition technique was used for the fabrication of Ge-Te rich GeTe-Sb2Te3 (Ge6Sb2Te9, Ge8Sb2Te11, Ge10Sb2Te13, and Ge12Sb2Te15) amorphous thin films. To evaluate the influence of GeTe content in the deposited films on physico-chemical properties of the GST materials, scanning electron microscopy with energy-dispersive X-ray analysis, X-ray diffraction and reflectometry, atomic force microscopy, Raman scattering spectroscopy, optical reflectivity, and sheet resistance temperature dependences as well as variable angle spectroscopic ellipsometry measurements were used to characterize as-deposited (amorphous) and annealed (crystalline) layers. Upon crystallization, optical functions and electrical resistance of the films change drastically, leading to large optical and electrical contrast between amorphous and crystalline phases. Large changes of optical/electrical properties are accompanied by the variations of thickness, density, and roughness of the films due to crystallization. Reflectivity contrast as high as ~0.21 at 405 nm was calculated for Ge8Sb2Te11, Ge10Sb2Te13, and Ge12Sb2Te15 layers.
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Affiliation(s)
- M. Bouška
- Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice, Czech Republic
| | - S. Pechev
- Institut de Chimie de la Matière Condensée de Bordeaux – CNRS, 87, av. du Dr. Albert Schweitzer, 33608 Pessac Cedex, France
| | - Q. Simon
- Institut de Chimie de la Matière Condensée de Bordeaux – CNRS, 87, av. du Dr. Albert Schweitzer, 33608 Pessac Cedex, France
| | - R. Boidin
- Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice, Czech Republic
| | - V. Nazabal
- Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice, Czech Republic
- Equipe Verres et Céramiques, UMR-CNRS 6226, Sciences Chimiques de Rennes (SCR), Université de Rennes 1, 35042 Rennes Cedex, France
| | - J. Gutwirth
- Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice, Czech Republic
| | - E. Baudet
- Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice, Czech Republic
| | - P. Němec
- Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice, Czech Republic
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13
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Nádvorník L, Němec P, Janda T, Olejník K, Novák V, Skoromets V, Němec H, Kužel P, Trojánek F, Jungwirth T, Wunderlich J. Long-range and high-speed electronic spin-transport at a GaAs/AlGaAs semiconductor interface. Sci Rep 2016; 6:22901. [PMID: 26980667 PMCID: PMC4793250 DOI: 10.1038/srep22901] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 02/24/2016] [Indexed: 11/09/2022] Open
Abstract
Spin-valves or spin-transistors in magnetic memories and logic elements are examples of structures whose functionality depends crucially on the length and time-scales at which spin-information is transferred through the device. In our work we employ spatially resolved optical pump-and-probe technique to investigate these fundamental spin-transport parameters in a model semiconductor system. We demonstrate that in an undoped GaAs/AlGaAs layer, spins are detected at distances reaching more than ten microns at times as short as nanoseconds. We have achieved this unprecedented combination of long-range and high-speed electronic spin-transport by simultaneously suppressing mechanisms that limit the spin life-time and the mobility of carriers. By exploring a series of structures we demonstrate that the GaAs/AlGaAs interface can provide superior spin-transport characteristics whether deposited directly on the substrate or embedded in complex semiconductor heterostructures. We confirm our conclusions by complementing the optical experiments with dc and terahertz photo-conductivity measurements.
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Affiliation(s)
- L Nádvorník
- Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 16253 Praha 6, Czech Republic.,Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 12116 Praha 2, Czech Republic
| | - P Němec
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 12116 Praha 2, Czech Republic
| | - T Janda
- Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 16253 Praha 6, Czech Republic.,Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 12116 Praha 2, Czech Republic
| | - K Olejník
- Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 16253 Praha 6, Czech Republic
| | - V Novák
- Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 16253 Praha 6, Czech Republic
| | - V Skoromets
- Institute of Physics ASCR, v.v.i., Na Slovance 2, 18221 Praha 8, Czech Republic
| | - H Němec
- Institute of Physics ASCR, v.v.i., Na Slovance 2, 18221 Praha 8, Czech Republic
| | - P Kužel
- Institute of Physics ASCR, v.v.i., Na Slovance 2, 18221 Praha 8, Czech Republic
| | - F Trojánek
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 12116 Praha 2, Czech Republic
| | - T Jungwirth
- Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 16253 Praha 6, Czech Republic.,School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - J Wunderlich
- Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 16253 Praha 6, Czech Republic.,Hitachi Cambridge Laboratory, J. J. Thomson Avenue, CB3 0HE Cambridge, UK
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Měřička P, Špaček M, Janoušek L, Dvořáček L, Štádler P, Vlachovský R, Guňka I, Honegrová B, Brandejs D, Štěrba L, Voxová B, Štěpánová V, Navrátil P, Staffa R, Němec P, Lindner J. Cryopreservation of vascular grafts for clinical use – Retrospective analysis of pre-freezing factors with potential impact on the quality and safety of vascular transplantations. Cryobiology 2015. [DOI: 10.1016/j.cryobiol.2015.10.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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15
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Adam R, Karam V, Delvart V, Trunečka P, Samuel D, Bechstein WO, Němec P, Tisone G, Klempnauer J, Rossi M, Rummo OO, Dokmak S, Krawczyk M, Pratschke J, Kollmar O, Boudjema K, Colledan M, Ericzon BG, Mantion G, Baccarani U, Neuhaus P, Paul A, Bachellier P, Zamboni F, Hanvesakul R, Muiesan P. Improved survival in liver transplant recipients receiving prolonged-release tacrolimus in the European Liver Transplant Registry. Am J Transplant 2015; 15:1267-82. [PMID: 25703527 DOI: 10.1111/ajt.13171] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 11/28/2014] [Accepted: 12/09/2014] [Indexed: 01/25/2023]
Abstract
This study was a retrospective analysis of the European Liver Transplant Registry (ELTR) performed to compare long-term outcomes with prolonged-release tacrolimus versus tacrolimus BD in liver transplantation (January 2008-December 2012). Clinical efficacy measures included univariate and multivariate analyses of risk factors influencing graft and patient survival at 3 years posttransplant. Efficacy measures were repeated using propensity score-matching for baseline demographics. Patients with <1 month of follow-up were excluded from the analyses. In total, 4367 patients (prolonged-release tacrolimus: n = 528; BD: n = 3839) from 21 European centers were included. Tacrolimus BD treatment was significantly associated with inferior graft (risk ratio: 1.81; p = 0.001) and patient survival (risk ratio: 1.72; p = 0.004) in multivariate analyses. Similar analyses performed on the propensity score-matched patients confirmed the significant survival advantages observed in the prolonged-release tacrolimus- versus tacrolimus BD-treated group. This large retrospective analysis from the ELTR identified significant improvements in long-term graft and patient survival in patients treated with prolonged-release tacrolimus versus tacrolimus BD in primary liver transplant recipients over 3 years of treatment. However, as with any retrospective registry evaluation, there are a number of limitations that should be considered when interpreting these data.
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Affiliation(s)
- R Adam
- Hepato-Biliary Center, AP-HP Paul Brousse Hospital, University of Paris-Sud, Inserm U 776, Villejuif, France
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16
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Hawlová P, Verger F, Nazabal V, Boidin R, Němec P. Test-photostability of pulsed laser deposited amorphous thin films from Ge-As-Te system. Sci Rep 2015; 5:9310. [PMID: 25797340 PMCID: PMC4369751 DOI: 10.1038/srep09310] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 12/16/2014] [Indexed: 11/11/2022] Open
Abstract
Amorphous thin films from Ge-As-Te system were prepared by pulsed laser deposition to study their intrinsic photostability, morphology, chemical composition, structure and optical properties. Photostability of fabricated layers was studied by spectroscopic ellipsometry within as-deposited as well as relaxed (annealed) layers. For irradiation, laser sources operating at three wavelengths in band gap region of the studied materials were employed. The results show that lowest values of photorefraction accompanied with lowest changes of band gap values were exhibited by Ge20As20Te60 thin films, which are therefore considered as the layers with highest photostability in relaxed state. The structure of the films is discussed based on Raman scattering spectroscopy data.
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Affiliation(s)
- P Hawlová
- Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, 53210 Pardubice, Czech Republic
| | - F Verger
- Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, 53210 Pardubice, Czech Republic
| | - V Nazabal
- 1] Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, 53210 Pardubice, Czech Republic [2] Institut des sciences chimiques de Rennes, UMR CNRS 6226, Equipe Verres et Céramiques, Université de Rennes 1, 35042 Rennes, France
| | - R Boidin
- Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, 53210 Pardubice, Czech Republic
| | - P Němec
- Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, 53210 Pardubice, Czech Republic
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17
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Nešpor D, Fila P, Černý J, Němec P. [Overview of primary sternal closure techniques]. Rozhl Chir 2015; 94:48-56. [PMID: 25659253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The aim of the overview study is to describe the currently used methods of primary median sternotomy closure in adult cardiac surgery. In the review of published literature, we draw on the data and focus on the methodology, indications, advantages, limitations, biomechanical and clinical results of the different methods in relation to the incidence of deep sternal wound complications after median sternotomy in adult cardiac surgery.Key words: sternum sternotomy adult cardiac surgery surgical procedures.
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18
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Kott O, Moritz RE, Šumbera R, Burda H, Němec P. Light propagation in burrows of subterranean rodents: tunnel system architecture but not photoreceptor sensitivity limits light sensation range. J Zool (1987) 2014. [DOI: 10.1111/jzo.12152] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- O. Kott
- Department of Zoology; Faculty of Science; University of South Bohemia; České Budějovice Czech Republic
| | - R. E. Moritz
- Department of General Zoology; Faculty of Biology; University of Duisburg-Essen; Essen Germany
| | - R. Šumbera
- Department of Zoology; Faculty of Science; University of South Bohemia; České Budějovice Czech Republic
| | - H. Burda
- Department of General Zoology; Faculty of Biology; University of Duisburg-Essen; Essen Germany
| | - P. Němec
- Department of Zoology; Faculty of Science; Charles University in Prague; Prague Czech Republic
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Gryl M, Seidler T, Stadnicka K, Matulková I, Němec I, Tesařová N, Němec P. The crystal structure and optical properties of a pharmaceutical co-crystal – the case of the melamine–barbital addition compound. CrystEngComm 2014. [DOI: 10.1039/c4ce00178h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Matulková I, Cihelka J, Pojarová M, Fejfarová K, Dušek M, Císařová I, Vaněk P, Kroupa J, Němec P, Tesařová N, Němec I. Molecular crystals of 2-amino-1,3,4-thiadiazole with inorganic oxyacids – crystal engineering, phase transformations and NLO properties. CrystEngComm 2014. [DOI: 10.1039/c3ce42306a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Hejsek L, Ernest J, Němec P, Rejmont L, Manethová K, Stepanov A, Rozsíval P. [Surgical treatment of very advanced rhegmatogenous retinal detachment]. Cesk Slov Oftalmol 2013; 69:248-252. [PMID: 24697537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Rhegmatogenous retinal detachment is a serious ocular pathology. Therapeutic options are surgical only. Surgery is in advanced stages technically and financially demanding. In this paper, we consider the results operated detachments, which were for their advancement, with respect to the technical possibilities of the present intraocular surgery, on the border of the surgical possibilities. The group consisted of 37 eyes of 37 patients who were followed prospectively and had in the affected eye very advanced (old) rhegmatogenous retinal detachment. As a method to confirtm any visual functions were used visual evoked potentials in flash monocular stimulation (F-VEP). All patients had a cerclage performed 12 mm from the limbus, 20G pars plana vitrectomy (PPV), in 2 was also performed cataract surgery (phacoemulsification with implantation of an artificial intraocular lens to the bag). Surgery was done in 23 of 37 patients (62 % of the whole group), with the remaining 14 eyes was not due to the severity of finding highly advanced retinal detachment. Attached retina at the end of the observation period had 14 eyes (61% of the patients, 38% of the whole group). In 5 eyes was due to local re-detachment in the periphery only stabilized finding (22% of operated eyes, 14% of all). The values of visual acuity in the subgroup of operated eyes were statistically significantly increased after surgery (Wilcoxon p = 0.036). The values of F-VEP were not statistically significantly different between operated and non-operated patients and was not found any statistically significant correlation between the vision (and even after surgery) and F-VEP in operated eyes. Anatomical success of surgical treatment of advanced retinal detachment is possible. But the correlation was not found in visual acuity and F-VEP or the severity of preoperative disturbed visual function, even in the improvement in the postoperative period. F-VEP is not a suitable marker for determining the indication for the procedure, or to the prognostics and therefore we can not use this technique to distinguish between operable and inoperable findings. Based on our clinical experience, we recommend carefully consider the suitability of surgical treatment of rhegmatogenous retinal detachment with low vision than the hand movement with the correct projection of light, when the duration is longer than three months and the anatomic findings is contractile anterior proliferative vitreoretinopathy.
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22
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Mejzlík V, Husová L, Kuman M, Stěpánková S, Ondrášek J, Němec P. [Liver transplant outcomes in Brno]. Vnitr Lek 2013; 59:663-667. [PMID: 24007219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The first liver transplant in the former Czechoslovakia took place in Brno on 2 February 1983; the patient concerned has lived for more than 30 years with a normally functioning liver and is one of the longest surviving patients after a liver transplant in Europe. The Cardiovascular and Transplantation Surgery Centre (CTSC) in Brno has experienced an increased development in the area of liver transplants since the mid 1990s. At present, about 30 patients a year undergo a transplantation, with 451 liver transplants in total as of 31 December 2012. The primary indication concerns liver cirrhosis of various etiologies, with an increasing number of cases of cirrhosis resulting from hepatitis C. Urgent liver transplants (for acute liver failure or primary dysfunction of first liver graft) amount to 11% of cases. There were 18 retransplants performed as of 31 December 2012, with 50% five year survival. The primary graft dysfunction was present in 7 patients (i.e. 1.5%). The 1 year survival rate of all patients after a liver transplant performed in CTSC is 92%, 5 year survival rate is 80%, and 10 year survival rate is 71%. Currently the parameters such as recipients age, donors age, and transplant waiting time has been statistically increasing; small recipients with a body weight below 70 kg especially have to wait for a significantly longer period of time (waiting median of 178 days). In CTSC Brno 14 combined simultaneous transplants (13 transplants of liver + kidney and one combined simultaneous transplants of liver + heart + kidney in 2005) have been performed as of 31 December 2012.
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Affiliation(s)
- V Mejzlík
- Centrum kardiovaskularni a transplantacni chirurgie Brno.
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23
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Studeník P, Němec P. [Development of immunosuppressant treatment after liver transplant]. Vnitr Lek 2013; 59:668-670. [PMID: 24007220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The history of liver transplants extends over more than 60 years. During the first 10 years the operations were carried out only as experiments and primarily focused on designing complex surgical techniques. In the 1960s the research focused on the development of immunosuppressants and the first clinical operations were performed. However, the outcomes of these interventions were very poor. The subsequent 2 decades witnessed the development of new and very efficient immunosuppressants, significantly improving patient survival rates. The number of operations and sites performing these interventions increased. In the United States in 1983, liver transplants were recognised as a clinical treatment method for liver conditions where all conservative options had failed. In the same year the first successful liver transplant was performed in Czechoslovakia. New surgical techniques bringing significant reduction of blood loss during the operation, reduction of over extensive grafts, splitting operations - when one organ may be used for 2 recipients - and collection of liver lobes from living donors resulted in a further increase in the number of transplants. The development of new immunosuppressive protocols have contributed to further improved survival rates of the patients while the majority of transplant sites achieve the longterm survival of 90%. However, the future of transplants lies in inducing the immunological tolerance of the body towards the transplanted organ with no immunosuppressive treatment administered.
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Affiliation(s)
- P Studeník
- Interni Klinika Lekarske Fakulty MU a FN u sv, Anny Brno.
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Mejzlík V, Husová L, Kuman M, Stěpánková S, Ondrášek J, Němec P. [Liver transplants in tumours and alcoholic cirrhoses]. Vnitr Lek 2013; 59:698-704. [PMID: 24007227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The treatment of hepatocellular carcinoma requires a multidisciplinary approach; liver transplant is suitable only in the minority of strictly selected patients. The CSTC Brno applies the so called Milan criteria. As of 31 December 2012 the CSTC Brno performed liver transplants in 16 patients with hepatocellular carcinoma in cirrhosis, with a five year survival rate of 40% and a 10 year survival after transplant of 20%. It is a paradox that the longest living (30 years) patient of CSTC Brno underwent the transplant for a large fibrolamellar hepatocellular carcinoma, which emphasises the prognostic significance of the tumour histology - criterion taken into account for practical reasons only in some indication schemes. Liver transplant for cholangiocarcinoma is no longer being carried out in CSTC. Five patients underwent this operation in the past and the longest living one survived for four years after the transplant. Benign liver tumours (adenomatosis, cystadenoma, hemangioma with compression symptoms) are rather rare indications and transplant results are positive. Four patients were transplanted for liver carcinoid, with one patient experiencing recurrence. The most frequent compact indication for liver transplant in CSTC Brno concerns alcoholic cirrhosis (24%, 108 patients); the survival rate of these patients after transplant is very good (81% 5 year survival and 68% 10 year survival). Likewise, efforts are made to select patients with a low risk of alcohol abuse after the transplant, which is, however, not very successful. The recurrence of some kind of alcohol abuse occurred in 26% transplanted patients, while seven died of alcoholic cirrhosis of the graft.
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Affiliation(s)
- V Mejzlík
- Centrum kardiovaskularni a transplantacni chirurgie Brno.
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25
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Procházková L, Němec P, Souček M. [Spondyloarthritides: current perspective on diagnosis and classification]. Vnitr Lek 2013; 59:383-390. [PMID: 23767453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Spondyloarthritides (SpA) are a heterogeneous group of chronic inflammatory diseases with common clinical features and genetic basis. They primarily affect the axial skeleton, especially the sacroiliac joint, other localizations of the affection being peripheral joints and entheses - typical of the group of spondyloarthritides. On the basis of the predominant affection of the axial or peripheral skeleton, they can be divided, according to the current classification criteria, into axial SpA and peripheral SpA. Apart from axial and peripheral articular manifestations, many patients also display extra articular manifestations, which can thus become an important diagnostic clue and also the first symptom of the disease. The most frequent of them are anterior uveitis, inflammatory bowel diseases, and psoriasis. Also the strong binding of spondyloarthritides to the positivity of HLA B27 antigen or a family history of the disease is important information which helps in the diagnosis. Comorbidities, the most common and important of which are cardiovascular diseases or osteoporosis and its consequences in the form of fractures, are an integral part of the issue of spondyloarthritides.
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Affiliation(s)
- L Procházková
- Revmatologicka ambulance II. Interni Kliniky Lekarske fakulty MU a FN u sv. Anny Brno.
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Adam Z, Krejčí J, Krejčí M, Němec P, Spinarová L, Zampachová V, Cermáková Z, Pika T, Pour L, Kořístek Z, Tomíška M, Szturz P, Král Z, Mayer J. [Heart transplantation and the subsequent treatment of AL amyloidosis]. Vnitr Lek 2013; 59:136-147. [PMID: 23461404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
UNLABELLED Severe damage to the heart caused by AL amyloid deposits is a contraindication of high-dose chemotherapy with autologous haematopoietic stem cell transplantation. Severe heart damage caused by AL amyloid results in frequent life-threatening complications, even during the course of the classical chemotherapy treatment and it often makes keeping to the treatment schedule impossible. Scheduling heart transplantation before the treatment of AL amyloidosis will significantly improve the patients overall condition and enable them to undergo the intensive AL amyloidosis treatment with the hope that a long-term complete remission may be achieved. CASE DESCRIPTIONS Transplantations of heart damaged by AL amyloid deposits were conducted in three patients; two men, age 48 and 54, and one woman, age 63. In the interval of 3-6 months from the heart transplantation before the scheduled AL amyloidosis treatment was initiated, an examination of bone marrow, the concentration of monoclonal immunoglobulin and free light chains was carried out. Both men had more than 10% of plasma cells in the bone marrow after the heart transplantation and the concentrations of the λ free light chains were pathologically increased. During the first-line therapy, autologous haematopoietic stem cells were harvested from peripheral blood after mobilizaton with granulocyte growth factor (filgrastim) at the dose of 5 µg/kg twice a day. During the administration of filgrastim until the end of the haematopoietic stem cell harvest, the combined immunosuppressive treatment was reduced and a corticosteroid dose was compensatory increased. The prophylactic antiviral drug valganciclovir was discontinued during the haematopoietic stem cell harvest. High-dose chemotherapy (melphalan 100 mg/m2) with autologous haematopoietic stem cell transplantation followed. In the interval from administering melphalan until the rise in neutrophil count over 2 x 109/l, antiviral prophylaxis was discontinued again, the immunosuppressive drug doses were reduced and corticoid doses were slightly increased. High-dose chemotherapy with melphalan at the of 100 mg/m2 was tolerated without major complications and without mucositis; however, in neither of the male patients did it lead to a complete haematological remission. Consequently, the second-line therapy followed using bortezomib combined with dexamethasone and also with cyclophosphamide or doxorubicin. One of these two patients reached a complete haematological remission after the bortezomib therapy; the values of free light chains were normal, immunofixation was negative, and clonal plasma cells were absent in the bone marrow. In the case of the other patient, the bortezomib therapy only induced partial remission. In this case, the third-line therapy followed, applying a combination of lenalidomide, dexamethasone and cyclophosphamide. This therapy significantly reduced the values of free light chains; however, their ratio remained pathological. To conclude, the latter response can be described as a very good partial remission. Both men currently show no signs of disease activity and are in a good clinical condition 28 and 30 months after the heart transplantation. The third heart transplantation, due to severe heart damage by AL amyloid deposits, was conducted in a woman aged 63. An examination of this woman three months after the heart transplantation showed that the original pathological values of free light chains became normal. The woman had approx. 8% of clonal plasma cells before the heart transplantation. Three months after the heart transplantation the bone marrow contained only 3% of polyclonal plasma cells. In this case, the immunosuppressive treatment with corticosteroids after the heart transplantation probably induced a complete haematologic remission. The woman is in a complete AL amyloidosis remission seven months after the heart transplantation. CONCLUSION It was beneficial to perform the heart transplantation first and to initiate the AL amyloidosis treatment no sooner than three months after the heart transplantation in patients with severe heart damage caused by AL amyloid deposits. If the patients are in a good clinical conditions, autologous haematopoietic stem cells can be harvested after the heart transplantation and high-dose chemotherapy can be offered to the patients. If this intensive treatment does not induce remission, it is necessary to apply additional alternative treatments.
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Affiliation(s)
- Z Adam
- Interni hematologicka a onkologicka klinika LF MU a FN Brno, Pracoviste Bohunice.
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Tesařová N, Šubrt J, Malý P, Němec P, Ellis CT, Mukherjee A, Cerne J. High precision magnetic linear dichroism measurements in (Ga,Mn)As. Rev Sci Instrum 2012; 83:123108. [PMID: 23277973 DOI: 10.1063/1.4771922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Investigation of magnetic materials using the first-order magneto-optical Kerr effects (MOKEs) is well established and is frequently used. On the other hand, the utilization of the second-order (or quadratic) magneto-optical (MO) effects for the material research is rather rare. This is due to the small magnitude of quadratic MO signals and the fact that the signals are even in magnetization (i.e., they do not change a sign when the magnetization orientation is reversed), which makes it difficult to separate second-order MO signals from various experimental artifacts. In 2005 a giant quadratic MO effect-magnetic linear dichroism (MLD)-was observed in the ferromagnetic semiconductor (Ga,Mn)As. This discovery not only provided a new experimental tool for the investigation of in-plane magnetization dynamics in (Ga,Mn)As using light at normal incidence, but it also motivated the development of experimental techniques for the measurement of second-order MO effects in general. In this paper we compare four different experimental techniques that can be used to measure MLD and to separate it from experimental artifacts. We show that the most reliable results are obtained when we monitor the polarization of reflected light while the magnetization of the sample is rotated by applying an external magnetic field. Using this technique we measure the MLD spectra of (Ga,Mn)As in a broad spectral range from 0.1 eV to 2.7 eV and we observe that MLD has a magnitude comparable to the polar MOKE signals in this material.
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Affiliation(s)
- N Tesařová
- Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 121 16 Prague 2, Czech Republic.
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Němec P. [Current opinions on gout, its diagnosis and treatment]. Vnitr Lek 2012; 58:928-937. [PMID: 23427951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Gout is a heterogenous group of metabolic diseases characterized by formation and deposition of sodium urate crystals in various tissues. Gouty arthritis is a rheumatic syndrome occurring in individuals with hyperuricaemia; this is an inflammatory disease of the musculoskeletal system with a presence of sodium urate crystals. Hyperuricaemia, i.e. pathologically increased levels of uric acid in the serum, represents the most important risk factor for the development of gouty arthritis. The causes of hyperuricaemia may include an increased production of uric acid and/or its reduced elimination from the body. Acute gouty arthritis is an early manifestation of gouty arthritis. When deposition of sodium urate crystals in tissues leads to a destruction of musculoskeletal system structures, this is called chronic tophaceous gouty arthritis. To treat chronic tophaceous gout, the uric acid levels must be kept below 360 μmol/l, deposits of sodium urate in tissues dissolved and their further formation prevented. Pharmacological treatment of chronic hyperuricaemia involves administration of uric acid level lowering drugs, particularly xanthine oxidase inhibitors and uricosurics. Hyperuricaemia is an important risk factor not only for the development of chronic tophaceous gout and renal impairment but some data also suggests a risk associated with cardiovascular diseases.
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Affiliation(s)
- P Němec
- Revmatologicka ambulance II. Interni Kliniky fakulty MU a FN u sv. Anny Brno.
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Ráček V, Němec P. [Rheumatoid arthritis - an independent risk factor for cardiovascular disease]. Vnitr Lek 2012; 58:834-838. [PMID: 23256829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Mortality in patients with rheumatoid arthritis compared with general population is increased and approximately one-half of the premature death is due to increased cardiovascular mortality. Traditional cardiovascular risk factors only partly explain increased risk of cardiovascular disease in patients with rheumatoid arthritis. The risk of cardiovascular disease associated with rheumatoid arthritis equals that of diabetes mellitus. Rheumatoid arthritis should be regarded as a strong independent cardiovascular risk factor as diabetes mellitus. The presence of chronic inflammation implicated in pathogenesis of rheumatoid arthritis and atherosclerosis could be the key mechanism that contributes to increased cardiovascular risk. Traditional cardiovascular risk factors reduction combined with tight disease control is recommended to reduce the risk of cardiovascular disease.
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Affiliation(s)
- V Ráček
- Revmatologicka ambbulance II. Interni Kliniky Lekarske Fakulty MU a FN u sv Anny Brno.
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Begall S, Burda H, Cervený J, Gerter O, Neef-Weisse J, Němec P. Further support for the alignment of cattle along magnetic field lines: reply to Hert et al. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2011; 197:1127-33; discussion 1135-6. [PMID: 22028177 PMCID: PMC3221857 DOI: 10.1007/s00359-011-0674-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2011] [Revised: 08/09/2011] [Accepted: 08/11/2011] [Indexed: 12/01/2022]
Abstract
Hert et al. (J Comp Physiol A, 2011) challenged one part of the study by Begall et al. (PNAS 105:13451–13455, 2008) claiming that they could not replicate the finding of preferential magnetic alignment of cattle recorded in aerial images of Google Earth. However, Hert and co-authors used a different statistical approach and applied the statistics on a sample partly unsuitable to examine magnetic alignment. About 50% of their data represent noise (resolution of the images is too poor to enable unambiguous measurement of the direction of body axes, pastures are on slopes, near settlements or high voltage power-lines, etc.). Moreover, the authors have selected for their analysis only ~ 40% of cattle that were present on the pastures analyzed. Here, we reanalyze all usable data and show that cattle significantly align their body axes in North–South direction on pastures analyzed by Hert and co-authors. This finding thus supports our previous study. In addition, we show by using aerial Google Earth images with good resolution, that the magnetic alignment is more pronounced in resting than in standing cattle.
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Affiliation(s)
- S Begall
- Department of General Zoology, Faculty of Biology, University of Duisburg-Essen, 45117, Essen, Germany.
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Jungwirth T, Horodyská P, Tesařová N, Němec P, Subrt J, Malý P, Kužel P, Kadlec C, Mašek J, Němec I, Orlita M, Novák V, Olejník K, Sobáň Z, Vašek P, Svoboda P, Sinova J. Systematic study of Mn-doping trends in optical properties of (Ga,Mn)As. Phys Rev Lett 2010; 105:227201. [PMID: 21231417 DOI: 10.1103/physrevlett.105.227201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 10/08/2010] [Indexed: 05/30/2023]
Abstract
We report on a systematic study of optical properties of (Ga,Mn)As epilayers spanning the wide range of accessible Mn(Ga) dopings. The material synthesis was optimized for each nominal Mn doping in order to obtain films which are as close as possible to uniform uncompensated (Ga,Mn)As mixed crystals. We observe a broad maximum in the mid-infrared absorption spectra whose position exhibits a prevailing blueshift for increasing Mn doping. In the visible range, a peak in the magnetic circular dichroism also shifts with increasing Mn doping. The results are consistent with the description of ferromagnetic (Ga,Mn)As based on the microscopic valence band theory. They also imply that opposite trends seen previously in the optical data on a limited number of samples are not generic and cannot serve as an experimental basis for postulating the impurity band model of ferromagnetic (Ga,Mn)As.
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Affiliation(s)
- T Jungwirth
- Institute of Physics ASCR, v.v.i., Cukrovarnicka´ 10, 162 53 Praha 6, Czech Republic
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Němec P, Zhang S, Nazabal V, Fedus K, Boudebs G, Moreac A, Cathelinaud M, Zhang XH. Photo-stability of pulsed laser deposited Ge(x)As(y)Se(100-x-y) amorphous thin films. Opt Express 2010; 18:22944-22957. [PMID: 21164633 DOI: 10.1364/oe.18.022944] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Quest for photo-stable amorphous thin films in ternary Ge(x)As(y)Se(100-x-y) chalcogenide system is reported. Studied layers were fabricated using pulsed laser deposition technique. Scanning electron microscope with energy dispersive X-ray analyzer, Raman scattering spectroscopy, transmittance measurements, variable angle spectroscopic ellipsometry, and non-linear imaging technique with phase object inside the 4f imaging system were employed to characterize prepared thin films. Their photo-stability/photo-induced phenomena in as-deposited and relaxed states were also investigated, respectively. In linear regime, we found intrinsically photo-stable relaxed layers within Ge(20)As(20)Se(60) composition. This composition presents also the highest optical damage threshold under non-linear optical conditions.
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Affiliation(s)
- P Němec
- Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice, Czech Republic
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Němec P, Nahálková P, Sprinzl D, Malý P, Gladilin VN, Devreese JT. Spin-sensitive differential transmission experiments in quasi-spherical CdS quantum dots. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/pssc.200672890] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Sprinzl D, Nahálková P, Devreese JT, Gladilin VN, Malý P, Němec P. Spin-polarised carriers in CdS quasi-spherical quantum dots. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/pssc.200564633] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Uhlíř J, Klimecký V, Němec P, Foltýn J, Kozák J. Zur Frage des Ersatzes und der Unterstützung des Herzens. Thorac Cardiovasc Surg 1970. [DOI: 10.1055/s-0028-1099187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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