OBJECTIVE: Introduction of the new method of videoassisted multiple direct revascularization of the heart muscle from left-sided minithoracotomy (LAST--Left Anterior Small Thoracotomy) using an automatic connector of central anastomoses Symmetry (St. Jude Medical ATG, Inc., St. Paul, MN) in patients indicated for re-operation of bypasses of the coronary arteries or with pathological conditions of the sternum and for the cosmetic effect of submammary incisions in women. METHOD: From September 2001 to the end of February 2002 15 patients with affections of three arteries had an operation from a LAST approach with videoscopic construction of central anastomoses by means of a Symmetry connector with portal entries and the use of extracorporeal circulation introduced from the groin without cardioplegic arrest. Nine men and six women were operated with a mean age of 68.7 years and a mean ejection fraction (EF) of 58.2%. In seven instances reoperation of aortocoronary bypasses was involved; two patients with multiple myelomas (morbus Kahler) had a brittle and cavernously altered sternum, all six women wanted a small skin incision below the breast. The criterion for ruling out the mentioned procedure was marked atherosclerotic affection of the ascendent aorta, affection of the arteries in the aortoiliac area and affection of one or two coronary arteries suitable for miniinvasive revascularization without extracorporeal circulation. Fourteen patients had an angiographic check up examination of the patency of grafts before they were discharged. RESULTS: The total number of distal anastomoses per patient was 3.13 +/- 0.6, the median period of extracorporeal circulation was 112 +/- 34 minutes and the mean time of operation 186 +/- 52 minutes. Blood losses were on average 425 ml/24 h without necessity of revision on account of haemorrhage. Eleven (73%) patients were subjected to an ultra fast track protocol with extubation on the operating table. The mean time spent in the postoperative department was 8.6 hours and the total hospitalization period 5.5 days. None of the operated patients died. Peroperative ischaemia of the heart muscle was not observed, in one instance the authors observed a newly developed atrial fibrillation. During an angiographic check-up the authors detected 6 (13.6%) stenoses and occlusions in 44 checked bridged vessels. CONCLUSION: The alternative approach reduces the risk of cardiac injury during reoperation and the danger of impaired healing of the sternotomical wound in patients with pathological conditions of the sternum, with contamination of the surrounding tissue (e.g. in tracheostomy) or malignant disease. The cosmetic effect of the submammary incision, the small inguinal incision and endoscopic saphenous vein harvesting should be considered in elective direct revascularization of the heart muscle in women. Bridging of the coronary arteries with optical assistance from minithoracotomy and with an automatic connector of central anastomoses seems to be a safe alternative of standard sternotomy only with methodological but not anatomical or functional restriction.

• MeSH
• anastomóza chirurgická přístrojové vybavení   MeSH
• chirurgické nástroje * MeSH
• hojení ran MeSH
• hrudní chirurgie video-asistovaná * MeSH
• koronární bypass přístrojové vybavení   MeSH
• lidé MeSH
• miniinvazivní chirurgické výkony přístrojové vybavení   MeSH
• reoperace MeSH
• senioři MeSH
• torakotomie metody   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH

Image analysis methods commonly used in forensic anthropology do not have desirable robustness properties, which can be ensured by robust statistical methods. In this paper, the face localization in images is carried out by detecting symmetric areas in the images. Symmetry is measured between two neighboring rectangular areas in the images using a new robust correlation coefficient, which down-weights regions in the face violating the symmetry. Raw images of faces without usual preliminary transformations are considered. The robust correlation coefficient based on the least weighted squares regression yields very promising results also in the localization of such faces, which are not entirely symmetric. Standard methods of statistical machine learning are applied for comparison. The robust correlation analysis can be applicable to other problems of forensic anthropology.

• MeSH
• dospělí MeSH
• lidé MeSH
• lineární modely MeSH
• mladiství MeSH
• mladý dospělý MeSH
• obličej anatomie a histologie   MeSH
• počítačové zpracování obrazu * MeSH
• soudní antropologie MeSH
• statistické modely * MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Single-cage boron cluster anions with at least 11 cluster atoms, free of bonded functional groups that strongly absorb UV light, and their cobalt complexes have been the investigated compounds. Their UV-absorption spectra have absolute maxima between 200 and 215 nm. Corresponding molar extinction coefficients that are of the order of 10(3)-10(4) L mol(-1) cm(-1) indicate medium detection sensitivity. Its reaching requires elimination of background electrolytes that weaken the UV-light beam in any way. Frequently used carboxylic acids and zwitterionic Good's buffers cannot be used as buffering compounds from this reason. Freshly prepared 1 mM solutions of boron cluster compounds in aqueous sodium chloride, chosen as indifferent electrolyte, which contain 20-30% (v/v) of methanol or acetonitrile, give zones free of tailing. After storing in the fridge, zones of the compounds became pronouncedly tailed even if their solutions remain clear and free of precipitation, turbidity or opalescence. The tailing usually disappeared if the acetonitrile or the methanol concentration in samples was 40-60% (v/v) depending on the dissolved compound hydrophobicity. Solutions of extremely hydrophobic compounds, stored in the fridge, require mild heating to 30-40 degrees C for half an hour for the avoiding of the tailing. Permanent slow decrease in effective mobilites of boron cluster anions was found if background electrolytes contained acetonitrile and beta-cyclodextrin. Analogous decrease was not observed with organic anions. Constant mobilities of boron cluster anions have been reached if acetonitrile was replaced with methanol. Analyte zones were more symmetrical in background electrolytes buffered with sodium borate of pH 9 than in background electrolytes buffered with sodium phosphate of pH 7.

• MeSH
• borany izolace a purifikace   MeSH
• elektroforéza kapilární metody   MeSH
• koncentrace vodíkových iontů MeSH
• pufry MeSH
• senzitivita a specificita MeSH
• spektrofotometrie ultrafialová MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• borany MeSH
• pufry MeSH

Trees are natural objects, where deviations through the branches amplify geometric data for 3D representation and bring challenges to various applications dealing with 3D models, such as compression, visualization, symmetry detection, and radiative transfer simulation. This data article describes dataset of approximately symmetric 3D tree models with manually identified predominant symmetry plane in each tree model. Parameters for procedural tree synthesis were manually adjusted to produce approximately bilaterally symmetric trees which are grouped into species with distinct features. In the last step, each tree was manually annotated with approximate symmetry plane. This dataset contains geometric data of branches, manually defined parameters for tree synthesis method, point clouds, and a division plane with a score of bilateral symmetry strength. The generated trees can be used as benchmark data for verification of approximate reflectional symmetry detection methods. Additionally, generated 3D tree models can be used for other applications requiring pregenerated trees, such as compression of tree models, instancing, decimation methods, and radiative transfer simulation and modeling.

• Klíčová slova
• 3D tree modeling, Approximate symmetry, Symmetry detection, Tree synthesis,
• Publikační typ
• časopisecké články MeSH

Multidimensional optical spectroscopy observes transient excitation dynamics through time evolution of spectral correlations. Its action-detected variants offer several advantages over the coherent detection and are thus becoming increasingly widespread. Nevertheless, a drawback of action-detected spectra is the presence of a stationary background of the so-called incoherent mixing of excitations from independent states that resembles a product of ground-state absorption spectra and obscures the excited-state signal. This issue is especially problematic in fluorescence-detected two-dimensional electronic spectroscopy (F-2DES) and fluorescence-detected pump-probe spectroscopy (F-PP) of extended systems, where large incoherent mixing arises from efficient exciton-exciton annihilation. In this work, we demonstrate on the example of F-2DES and F-PP an inherent spectro-temporal symmetry of action-detected spectra, which allows general, system-independent subtraction of any stationary signals including incoherent mixing. We derive the expressions for spectra with normal and reversed time ordering of the pulses, relating these to the symmetry of the system response. As we show both analytically and numerically, the difference signal constructed from spectra with normal and reversed pulse ordering is free of incoherent mixing and highlights the excited-state dynamics. We further verify the approach on the experimental F-PP spectra of a molecular squaraine heterodimer and the F-2DES spectra of the photosynthetic antenna light-harvesting complex 2 of purple bacteria. The approach is generally applicable to action-detected 2DES and pump-probe spectroscopy without experimental modifications and is independent of the studied system, enabling their application to large systems such as molecular complexes.

• Publikační typ
• časopisecké články MeSH

Altermagnets are an emerging elementary class of collinear magnets. Unlike ferromagnets, their distinct crystal symmetries inhibit magnetization while, unlike antiferromagnets, they promote strong spin polarization in the band structure. The corresponding unconventional mechanism of time-reversal symmetry breaking without magnetization in the electronic spectra has been regarded as a primary signature of altermagnetism but has not been experimentally visualized to date. We directly observe strong time-reversal symmetry breaking in the band structure of altermagnetic RuO2 by detecting magnetic circular dichroism in angle-resolved photoemission spectra. Our experimental results, supported by ab initio calculations, establish the microscopic electronic structure basis for a family of interesting phenomena and functionalities in fields ranging from topological matter to spintronics, which are based on the unconventional time-reversal symmetry breaking in altermagnets.

• Publikační typ
• časopisecké články MeSH

PURPOSE: Early identification of ischemic stroke plays a significant role in treatment and potential recovery of damaged brain tissue. In noncontrast CT (ncCT), the differences between ischemic changes and healthy tissue are usually very subtle during the hyperacute phase (< 8 h from the stroke onset). Therefore, visual comparison of both hemispheres is an important step in clinical assessment. A quantitative symmetry-based analysis of texture features of ischemic lesions in noncontrast CT images may provide an important information for differentiation of ischemic and healthy brain tissue in this phase. METHODS: One hundred thirty-nine (139) ncCT scans of hyperacute ischemic stroke with follow-up magnetic resonance diffusion-weighted (MR-DW) images were collected. The regions of stroke were identified in the MR-DW images, which were spatially aligned to corresponding ncCT images. A state-of-the-art symmetric diffeomorphic image registration was utilized for the alignment of CT and MR-DW, for identification of individual brain hemispheres, and for localization of the region representing healthy tissue contralateral to the stroke cores. Texture analysis included extraction and classification of co-occurrence and run-length texture-based image features in the regions of ischemic stroke and their contralateral regions. RESULTS: The classification schemes achieved area under the receiver operating characteristic [Az] ≈ 0.82 for the whole dataset. There was no statistically significant difference in the performance of classifiers for the data sets with time between 2 and 8 hours from symptom onset. The performance of the classifiers did not depend on the size of the stroke regions. CONCLUSIONS: The results provide a set of optimal texture features which are suitable for distinguishing between hyperacute ischemic lesions and their corresponding contralateral brain tissue in noncontrast CT. This work is an initial step toward development of an automated decision support system for detection of hyperacute ischemic stroke lesions on noncontrast CT of the brain.

• Klíčová slova
• hyperacute ischemic stroke, image registration, noncontrast computed tomography (ncCT) classification, texture analysis,
• MeSH
• cévní mozková příhoda komplikace   diagnostické zobrazování   MeSH
• ischemie mozku komplikace   MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• počítačová rentgenová tomografie * MeSH
• počítačové zpracování obrazu metody   MeSH
• rozhodovací stromy MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• senzitivita a specificita MeSH
• support vector machine MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Green microalgae of the Micrasterias lineage are unicellular microorganisms with modular morphology consisting of successively differentiated lobes. Due to their morphological diversity and peculiar morphogenesis, these species are important model systems for studies of cytomorphogenesis and cellular plasticity. Interestingly, the phylogenetic structure of the Micrasterias lineage and most other Desmidiales is poorly related to the traditional morphological characters used for delimitation of taxa. In this study, we focused on symmetry breaking between adjacent cellular lobes in relation to phylogeny of the studied species. While pronounced morphological asymmetry between the adjacent lobes is typical for some species, others have been characterized by the almost identical morphologies of these structures. We asked whether there is any detectable average shape asymmetry between the pairs of lobes and terminal lobules in 19 Micrasterias species representing all major clades of this desmidiacean lineage. Then, we evaluated whether the asymmetric patterns among species are phylogenetically structured. The analyses showed that the phylogeny was in fact strongly related to the patterns of morphological asymmetry between the adjacent cellular lobes. Thus, evolution of the asymmetric development between the adjacent lobes proved to be the key event differentiating cellular shape patterns of Micrasterias. Conversely, the phylogeny was only weakly related to asymmetry between the pairs of terminal lobules. The subsequent analyses of the phylogenetic morphological integration showed that individual hierarchical levels of cellular morphology were only weakly coordinated with regard to asymmetric variation among species. This finding indicates that evolutionary differentiation of morphogenetic processes leading to symmetry breaking may be relatively independent at different branching levels. Such modularity is probably the key to the evolvability of cellular shapes, leading to the extraordinary morphological diversity of these intriguing microalgae.

• Klíčová slova
• Asymmetry, Cytomorphogenesis, Desmidiales, Geometric morphometrics, Phenotype evolution, Phylomorphospace,
• Publikační typ
• časopisecké články MeSH

The separation of seven phenolic compounds including gallic acid, chlorogenic acid, epicatechin, quercitrin, rutin, phloridzin, and phloretin present in apple peel and pulp and differing in elution properties has been optimized using high-performance liquid chromatography with diode array detection. Several stationary phases were tested to achieve the efficient separation of phenolic compounds in fruit extracts and C18 was found to be the most efficient. Core-shell and fully porous C18 packings were assessed with respect to the complex composition of the fruit extracts. The developed high-performance liquid chromatography method comprised gradient elution in which mobile phase A was water at pH 2.8 adjusted with acetic acid and B was acetonitrile. The gradient shape was the following: 0 min 95% A/5% B, 2.5 min 85% A/15% B, 12 min 50% A/50% B, 15 min 95% A/5% B. The flow rate was 1 mL/min, injection volume 10 μL, and UV detection at 255, 280, 320, and 365 nm was applied. Our method was validated for both C18 core-shell and fully porous packings. The resolution 6.2-14.8, symmetry 0.99-1.34, peak capacity 18-60, peak area repeatability 0.45-1.00% relative standard deviation, calibration range 0.125-5 mg/mL (0.25-10 mg/mL for chlorogenic acid and rutin), correlation coefficients of calibration curve 0.9976-0.9997, and accuracy evaluated as recovery 95.56-107.54% were determined for the core-shell column.

• Klíčová slova
• apple, core-shell particles, diode array detection, high-performance liquid chromatography, phenolic compounds,
• MeSH
• fenoly analýza   MeSH
• Malus chemie   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fenoly MeSH

Riociguat is a novel antihypertensive drug for the treatment of pulmonary hypertension. We present electrophoretic characterization, i.e. migration behavior of riociguat and metabolite M1 as support for optimized CZE/MS assay. Fundamental separation parameters, such as peak width, symmetry, and resolution are studied in a series of ammonium formate buffers within pH range 2.60-5.61. The narrow region of peak symmetry lies close to pH 4.0 for both analytes. Accordingly, the value of resolution maximizes in a background electrolyte adjusted to pH 4.10. Basic calibration parameters estimated from CZE experiments with absorption photometric and mass spectrometric detection of riociguat and metabolite M1 were evaluated. More than three orders lower LOD was achieved with high resolution mass spectrometric detection. The observed difference in the sensitivity of both detection techniques gives priority to the utilization of CZE/MS in practice. The values of dissociation constants of riociguat and metabolite M1, pKBH , were determined from CZE measurements in lithium formate and lithium acetate background electrolytes with constant ionic strength. The value of pKBH = 4.30 ± 0.02 for riociguat corresponds well to the value already presented in the literature. According to our observation, metabolite M1 behaves like a slightly stronger base with estimated pKBH = 4.40 ± 0.02.

• Klíčová slova
• Capillary electrophoresis, Dissociation constant, Fragmentation, Mass spectrometry, Riociguat,
• MeSH
• elektroforéza kapilární metody   MeSH
• hmotnostní spektrometrie metody   MeSH
• lidé MeSH
• limita detekce MeSH
• lineární modely MeSH
• pyrazoly analýza   krev   chemie   metabolismus   MeSH
• pyrimidiny analýza   krev   chemie   metabolismus   MeSH
• reprodukovatelnost výsledků MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• pyrazoly MeSH
• pyrimidiny MeSH
• riociguat MeSH Prohlížeč