Publications by authors named "Petr Jakubec"

35 Publications

Graphene with Covalently Grafted Amino Acid as a Route Toward Eco-Friendly and Sustainable Supercapacitors.

ChemSusChem 2021 Jul 20. Epub 2021 Jul 20.

Palacky University Olomouc: Univerzita Palackeho v Olomouci, Department of Physical Chemistry, Slechtitelu 27, 779 00, Olomouc, CZECH REPUBLIC.

Eco-friendly, electrochemically active electrode materials based on covalent graphene derivatives offer enormous potential for energy storage applications. However, covalent grafting of functional groups onto graphene's surface is challenging due to its low reactivity. We employed fluorographene chemistry to graft an arginine moiety via its guanidine group homogeneously on both sides of graphene. By tuning the reaction conditions and adding a non-toxic, pore-forming agent, we achieved an optimum degree of functionalization and hierarchical porosity in the material. This tripled the specific surface area and yielded a high capacitance value of ~390 F/g at a current density of 0.25 A/g. The applicability of the electrode material was investigated under typical operating conditions by testing an assembled supercapacitor device for up to 30000 charging/discharging cycles, revealing capacitance retention of 82.3%. This work enables the preparation of graphene derivatives with covalently grafted amino acids for technologically important applications, such as supercapacitor-based energy storage.
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http://dx.doi.org/10.1002/cssc.202101039DOI Listing
July 2021

Prognostic impact of PD-1 and PD-L1 expression in malignant pleural mesothelioma: an international multicenter study.

Transl Lung Cancer Res 2021 Apr;10(4):1594-1607

Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Vienna, Austria.

Background: Programmed cell death 1/programmed death ligand 1 (PD-1/PD-L1) immune-checkpoint blockade is a promising new therapeutic strategy in cancer. However, expression patterns and prognostic significance of PD-L1 and PD-1 are still controversial in human malignant pleural mesothelioma (MPM).

Methods: Formalin-fixed paraffin-embedded (FFPE) tumor samples from 203 MPM patients receiving standard treatment without immunotherapy were collected from 5 European centers. PD-L1 and PD-1 expression of tumor cells (TCs) and tumor-infiltrating lymphocytes (TILs) were measured by immunohistochemistry and correlated with clinical parameters and long-term outcome.

Results: High (>10%) PD-L1 TC and PD-1 TILs expressions were found in 18 (8%) and 39 (24%) patients, respectively. PD-L1 was rarely expressed by TILs [≥1%, n=13 (8%); >10%, n=1]. No significant associations were found between the PD-L1 or PD-1 expression of TCs or TILs and clinicopathological parameters such as stage or histological subtype. Notably, patients with high (>10%) TC-specific PD-L1 expression exhibited significantly worse median overall survival (OS) (6.3 15.1 months of those with low TC PD-L1 expression; HR: 2.51, P<0.001). In multivariate cox regression analysis adjusted for clinical parameters, high TC PD-L1 expression (>10%) proved to be an independent negative prognostic factor for OS (HR: 2.486, P=0.005). There was no significant correlation between PD-L1 or PD-1 expression of TILs and OS.

Conclusions: In this multicenter cohort study, we demonstrate that high (>10%) PD-L1 expression of TCs independently predicts worse OS in MPM. Further studies are warranted to investigate the value of PD-L1/PD-1 expression as a marker for treatment response in MPM patients receiving immunotherapy.
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http://dx.doi.org/10.21037/tlcr-20-1114DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8107750PMC
April 2021

New Limits for Stability of Supercapacitor Electrode Material Based on Graphene Derivative.

Nanomaterials (Basel) 2020 Aug 31;10(9). Epub 2020 Aug 31.

Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University, Šlechtitelů 27, 78371 Olomouc, Czech Republic.

Supercapacitors offer a promising alternative to batteries, especially due to their excellent power density and fast charging rate capability. However, the cycling stability and material synthesis reproducibility need to be significantly improved to enhance the reliability and durability of supercapacitors in practical applications. Graphene acid (GA) is a conductive graphene derivative dispersible in water that can be prepared on a large scale from fluorographene. Here, we report a synthesis protocol with high reproducibility for preparing GA. The charging/discharging rate stability and cycling stability of GA were tested in a two-electrode cell with a sulfuric acid electrolyte. The rate stability test revealed that GA could be repeatedly measured at current densities ranging from 1 to 20 A g without any capacitance loss. The cycling stability experiment showed that even after 60,000 cycles, the material kept 95.3% of its specific capacitance at a high current density of 3 A g. The findings suggested that covalent graphene derivatives are lightweight electrode materials suitable for developing supercapacitors with extremely high durability.
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http://dx.doi.org/10.3390/nano10091731DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7558132PMC
August 2020

Hierarchical Porous Graphene-Iron Carbide Hybrid Derived From Functionalized Graphene-Based Metal-Organic Gel as Efficient Electrochemical Dopamine Sensor.

Front Chem 2020 30;8:544. Epub 2020 Jul 30.

Faculty of Science, Regional Centre of Advanced Technologies and Materials, Palacký University Olomouc, Olomouc, Czechia.

A metal-organic gel (MOG) similar in constitution to MIL-100 (Fe) but containing a lower connectivity ligand (5-aminoisophthalate) was integrated with an isophthalate functionalized graphene (IG). The IG acted as a structure-directing templating agent, which also induced conductivity of the material. The [email protected] was pyrolyzed at 600°C to obtain MGH-600, a hybrid of Fe/FeC/FeO enveloped by graphene. MGH-600 shows a hierarchical pore structure, with micropores of 1.1 nm and a mesopore distribution between 2 and 6 nm, and Brunauer-Emmett-Teller surface area amounts to 216 m/g. Furthermore, the MGH-600 composite displays magnetic properties, with bulk saturation magnetization value of 130 emu/g at room temperature. The material coated on glassy carbon electrode can distinguish between molecules with the same oxidation potential, such as dopamine in presence of ascorbic acid and revealed a satisfactory limit of detection and limit of quantification (4.39 × 10 and 1.33 × 10 M, respectively) for the neurotransmitter dopamine.
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http://dx.doi.org/10.3389/fchem.2020.00544DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7409389PMC
July 2020

Efficacy and analgesic use during the therapy of iatrogenic pneumothorax using Pleuralvent™ and Chest Tube (ASPIRATE): A randomised controlled trial protocol.

Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2020 Jun 9;164(2):213-215. Epub 2020 Mar 9.

Emergency Department, West Middlesex University Hospital, London, United Kingdom of Great Britain and Northern Ireland.

Background: Iatrogenic pneumothorax is a common complication of various diagnostic and therapeutic procedures such as transbronchial lung biopsies. The classical mode of treatment is chest tube insertion. Pneumothorax devices are now available on the market but there is a dearth of data on their efficacy to treat iatrogenic pneumothorax. It is important to provide such data as the pathophysiology of iatrogenic pneumothorax is different in comparison with spontaneous pneumothorax for which some data is available.

Methods: This is a randomized, non-blinded, actively controlled trial of effectivity of iatrogenic pneumothorax treatment using the Pleuralvent™ device and chest tube insertion (16F). The secondary aim is to compare the overall pain level and the need for analgesic treatment in both treatment arms. We are planning to enrol 126 patients (63 in each treatment arm).

Discussion: Preliminary results showed similar effectivity of the Pleuralvent™ system compared to large bore chest tube insertion. This randomized clinical trial should confirm these results and prove that the Pleuralvent™ system is an effective way of treatment of patients with iatrogenic pneumothorax. If Pleuralvent™ proves to have the same level of efficacy, it may become the standard of care of patients with iatrogenic pneumothorax.

Trial Registration: ClinicalTrials.gov Identifier: NCT03700554.
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http://dx.doi.org/10.5507/bp.2020.008DOI Listing
June 2020

Neurogenic pulmonary oedema as a rare complication of epileptic seizures.

Adv Respir Med 2019 ;87(5):298-300

Department of Respiratory Medicine, Faculty of Medicine and Dentistry, Palacky University and University Hospital Olomouc, Czech Republic.

Introduction: Neurogenic pulmonary oedema (NPE) is avery rare complication of epileptic seizures, which could potentially increase mortality.

Material And Methods: The case of a66-year-old male patient with NPE caused by repeated epileptic seizures is reported. Rapid resolution of pulmonary oedema is well documented by X-ray and computed tomography images.

Conclusions: Neurogenic pulmonary oedema could potentially increase mortality, and thus, it is important to perform achest X-ray in all patients presenting with seizures and dyspnoea.
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http://dx.doi.org/10.5603/ARM.2019.0052DOI Listing
April 2020

Thermally reduced fluorographenes as efficient electrode materials for supercapacitors.

Nanoscale 2019 Nov 1;11(44):21364-21375. Epub 2019 Nov 1.

Regional Centre for Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University Olomouc, 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic.

There is an urgent need for a simple and up-scalable method for the preparation of supercapacitor electrode materials due to increasing global energy consumption worldwide. We have discovered that fluorographene exhibits great potential for the development of new kinds of supercapacitors aimed at practical applications. We have shown that time control of isothermal reduction of fluorographite at 450 °C under a hydrogen atmosphere led to the fine-tuning of fluorine content and electronic properties of the resulting fluorographene derivatives. Charge transfer resistances (R) of the thermally reduced fluorographenes (TRFGs) were decreased with respect to the pristine fluorographene; however, the Rvs. time-of-reduction plot showed a v-shaped profile. The specific capacitance vs. time-of-reduction of TRFG followed the v-shaped trend, which could be the result of the decreasing content of sp carbons and increasing content of structural defects. An optimized material exhibited values of specific capacitance up to 539 F g recorded at a current density of 0.25 A g and excellent cycling durability with 100% specific capacitance retention after 1500 cycles in a three-electrode configuration and 96.7% of specific capacitance after 30 000 cycles in a two-electrode setup.
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http://dx.doi.org/10.1039/c9nr07255aDOI Listing
November 2019

Chemical Tuning of Specific Capacitance in Functionalized Fluorographene.

Chem Mater 2019 Jul 7;31(13):4698-4709. Epub 2019 Jun 7.

Regional Centre for Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University Olomouc, 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic.

Owing to its high surface area and excellent conductivity, graphene is considered an efficient electrode material for supercapacitors. However, its restacking in electrolytes hampers its broader utilization in this field. Covalent graphene functionalization is a promising strategy for providing more efficient electrode materials. The chemistry of fluorographene is particularly attractive as it allows scalable chemical production of useful graphene derivatives. Nevertheless, the influence of chemical composition on the capacitance of graphene derivatives is a largely unexplored field in nanomaterials science, limiting further development of efficient graphene-based electrode materials. In the present study, we obtained well-defined graphene derivatives differing in chemical composition but with similar morphologies by controlling the reaction time of 5-aminoisophthalic acid with fluorographene. The gravimetric specific capacitance ranged from 271 to 391 F g (in 1 M NaSO), with the maximum value achieved by a delicate balance between the amount of covalently grafted functional groups and density of the sp carbon network governing the conductivity of the material. Molecular dynamics simulations showed that covalent grafting of functional groups with charged and ionophilic/hydrophilic character significantly enhanced the ionic concentration and hydration due to favorable electrostatic interactions among the charged centers and ions/water molecules. Therefore, conductive and hydrophilic graphitic surfaces are important features of graphene-based supercapacitor electrode materials. These findings provide important insights into the role of chemical composition on capacitance and pave the way toward designing more efficient graphene-based supercapacitor electrode materials.
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http://dx.doi.org/10.1021/acs.chemmater.9b00655DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6662882PMC
July 2019

Alkynylation of graphene via the Sonogashira C-C cross-coupling reaction on fluorographene.

Chem Commun (Camb) 2019 Jan;55(8):1088-1091

Regional Centre for Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University Olomouc, 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic.

We report successful grafting of alkynyl groups onto graphene via the Sonogashira reaction between fluorographene and terminal alkynes. Theoretical calculations revealed that fluorographene can efficiently bind and oxidize the palladium catalyst on electrophilic sites activated by fluorine atoms. This paves the way towards conductive and mechanically robust 3D covalent networks.
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http://dx.doi.org/10.1039/c8cc08492kDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6350624PMC
January 2019

Real life adjuvant chemotherapy uptake and survival in patients with non-small cell lung cancer after complete resection.

Curr Med Res Opin 2018 09 9;34(9):1687-1694. Epub 2018 Jul 9.

c Department of Molecular Pathology , Palacky University , Olomouc , Czech Republic.

Objectives: Adjuvant chemotherapy (AC) in non-small cell lung cancer (NSCLC) has become a standard of care in patients with stages IIA, IIB, and IIIA after complete tumor resection. Utilization and outcome of AC in routine practice is described in a few studies, with non-conclusive results.

Materials And Methods: This retrospective study included consecutive patients with NSCLC who underwent curative-intent surgery. Data of AC uptake in stages IB (tumor of ≥4 cm in diameter), II, and IIIA, and reasons of AC omission were evaluated according to medical records. Mortality risk among patients treated with surgery (only) and different types of AC in routine practice was compared.

Results: AC was applied to 79% of patients with stages IB (tumor of ≥4 cm in diameter), II, and IIIA, and was associated with an improved median of overall survival (HR = 0.69; 95% CI = 0.44-1.06). Significantly longer survival was achieved in the sub-group treated with platinum and oral vinorelbine (HR = 0.575, 95% CI = 0.339-0.974), and the longest survival was among patients treated with oral vinorelbine and cisplatin (HR = 0.371, 95% CI = 0.168-0.820).

Conclusions: AC utilization should be based on co-operation between surgeons, pneumo-oncologists, and patients. Rational use of AC offers better survival in routine practice.
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http://dx.doi.org/10.1080/03007995.2018.1490254DOI Listing
September 2018

[The complications after lung transplantation].

Vnitr Lek Winter 2018;63(11):848-859

Lung transplantation (LuTx) is an important treatment for a selected group of patients in the terminal stage of a number of lung diseases, which can bring them a significant improvement in quality of life and long-term survival. Nowadays a perioperative period is not significant limitation for patient survival due to the development of transplant surgery, but the period of months to years after LuTx is crucial for survival. The post-transplant period is very complicated for LuTx patients due to a special treatment regimen, special medication, especially immunosuppressive drugs and the possibility of many complications, whether early or late or acute or chronic. These complications can be divided into several groups. These are rejections, infections, tumors, non-infectious pulmonary complications, and extrapulmonary complications. This is a very wide range of diverse states and to cope with them, it is necessary, apart from good patient co-operation, to team together with specialists in many fields of medicine. But the reward is the satisfaction, good quality of life and long-term survival of transplanted patients.Key words: infection - lung transplantation - rejection - tumours.
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April 2018

[Hospital-acquired pneumonias].

Vnitr Lek Winter 2018;63(11):776-785

Nosocomial infections are a common complication of hospital care. Hospital-acquired (HAP) pneumonia is one of the most common nosocomial infections and it is the most dangerous in terms of mortality. The problem is mainly selected hospital bacterial strains with rising antibiotic resistance. Diagnosis of the cause of pneumonia is difficult and often does not lead to a positive result. Management is complex and is based on timely and appropriate empirical antibiotic treatment. Local and extrapulmonary complications are relatively common and they increase morbidity and mortality. Prognosis of the HAP is often unfavorable, especially in the elderly and polymorbid individuals.Key words: complications - etiology - hospital-acquired pneumonia - management.
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April 2018

[Diagnostics and treatment of community-acquired pneumonia - simplicity is the key to success].

Vnitr Lek Winter 2018;63(11):770-775

Pneumonia is the most wide-spread infectious disease and requires unrelenting attention. It is defined as an acute inflammatory disease affecting pulmonary alveoli, respiratory bronchioles and the pulmonary interstitium. In recent years we have seen the endeavour to rationalize the approach to pneumonias and utilize the current methods of administering effective antibiotics to reduce occurrence of complications, limit the number of hospitalizations and shorten the length of treatment. With the awareness of all the potential agents it is empiric therapy which predominates, being supported by the knowledge of a regional epidemiological situation, good diagnosing and experience of rational antibiotic treatment. Very important is categorization of patients based on possible risks of complications and mortality. Considering that an appropriate form of treatment is chosen: outpatient care or hospitalization.Key words: community-acquired pneumonia - treatment criteria - prognosis - occurrence.
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April 2018

Management of mechanical ventilation in patients with hospital-acquired pneumonia: A retrospective, observational study.

Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2018 Jun 2;162(2):127-133. Epub 2017 Nov 2.

Department of Pulmonary Diseases and Tuberculosis, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic.

Background: Hospital-acquired pneumonia (HAP) in intensive care patients is a frequent reason for mechanical ventilation (MV). The management of MV and ventilator weaning vary, depending on the type of lung inflammation. This retrospective, observational study screened the data from all patients admitted to the intensive care unit (ICU) of the Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc between 2011 and 2016. The aims were to determine the parameters of pressure-controlled ventilation, the frequencies of tracheostomy, bronchoscopy, reconnection to MV, the length of ICU and hospital stay and the mortality in subgroups with early-/late-onset HAP compared to a subgroup with community-acquired pneumonia (CAP) and patients with MV without pneumonia. The primary outcome of this study was MV length.

Results: Over the study period, a total of 2672 patients were hospitalised. Excluded were 137 organ donors, 66 patient without MV and 20 patients placed on volume-controlled ventilation. The cohort comprised 2.447 patients requiring MV. A total of 1.927 patients (78.7%) were indicated for MV without signs of pneumonia. CAP was diagnosed in 131 patients (5.4%). The criteria for HAP were met by 389 patients (16.0%). Early-onset and late-onset HAP was diagnosed in 63 (2.6%) and 326 (13.3%) patients, respectively. In the subgroups without pneumonia, with CAP, early- and late-onset HAP, the median MV times were 3, 6, 6 and 12 days, respectively, and the median peak inspiratory pressure (Pinsp) of MV was 20, 25, 25 and 27 cm HO, respectively. The median positive end-expiratory pressure (PEEP) was 5, 8, 8 and 11 cm HO, respectively. The median inspired oxygen concentrations (FiO) were 0.45, 0.7, 0.7 and 0.8, respectively. The median length of hospital stays was 8, 15, 15 and 17 days. The mortality rates were 11.4%, 3.8%, 9.5% and 31.3%, respectively.

Conclusions: During MV, the late-onset HAP subgroup was shown to have the highest Pinsp, PEEP and FiO, the longest MV time, ICU and hospital stay, the highest frequency of tracheostomy, reconnection to MV, pulmonary hygiene bronchoscopy and the highest mortality compared to the early-onset HAP and CAP subgroups. The lowest values were found in the mechanically ventilated patients without pneumonia. The differences were due to the severity of lung damage that is graduated from CAP over early-onset HAP after late-onset HAP.
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http://dx.doi.org/10.5507/bp.2017.047DOI Listing
June 2018

A simple high-yield synthesis of high-purity Hägg carbide (χ-FeC) nanoparticles with extraordinary electrochemical properties.

Nanoscale 2017 Jul;9(29):10440-10446

Regional Centre of Advanced Technologies and Materials, Departments of Experimental Physics and Physical Chemistry, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic.

Iron carbides are of eminent interest in both fundamental scientific research and in the industry owing to their properties such as excellent mechanical strength and chemical inertness. They have been found very effective in Fischer-Tropsch synthesis exploring heterogeneous catalysis for the production of chemicals such as liquid fuel and they have also been employed as successful promoters for the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). However, so far there have been only a few reports on the application of iron carbide nanoparticles in the field of electrochemical sensing. Here, we present a stable form of Hägg carbide nanoparticles synthesized from a rare form of iron(iii) oxide (β-FeO). The as-prepared nanomaterial was characterized employing X-ray powder diffraction and Mössbauer spectroscopy to prove its composition as well as an extraordinary high purity level. It turned out that Hägg carbide nanoparticles prepared by thermally treated β-FeO exhibited excellent electrochemical properties including low charge transfer resistivity (R) compared to the other tested materials. Moreover, the Hägg carbide nanoparticles were tested as a promising electrocatalyst for voltammetric detection of the antibiotic metronidazole proving its practical applicability.
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http://dx.doi.org/10.1039/c7nr02383aDOI Listing
July 2017

Cyanographene and Graphene Acid: Emerging Derivatives Enabling High-Yield and Selective Functionalization of Graphene.

ACS Nano 2017 03 20;11(3):2982-2991. Epub 2017 Feb 20.

Regional Centre for Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University Olomouc , 17. listopadu 1192/12, 771 46 Olomouc, Czech Republic.

Efficient and selective methods for covalent derivatization of graphene are needed because they enable tuning of graphene's surface and electronic properties, thus expanding its application potential. However, existing approaches based mainly on chemistry of graphene and graphene oxide achieve only limited level of functionalization due to chemical inertness of the surface and nonselective simultaneous attachment of different functional groups, respectively. Here we present a conceptually different route based on synthesis of cyanographene via the controllable substitution and defluorination of fluorographene. The highly conductive and hydrophilic cyanographene allows exploiting the complex chemistry of -CN groups toward a broad scale of graphene derivatives with very high functionalization degree. The consequent hydrolysis of cyanographene results in graphene acid, a 2D carboxylic acid with pK of 5.2, showing excellent biocompatibility, conductivity and dispersibility in water and 3D supramolecular assemblies after drying. Further, the carboxyl groups enable simple, tailored and widely accessible 2D chemistry onto graphene, as demonstrated via the covalent conjugation with a diamine, an aminothiol and an aminoalcohol. The developed methodology represents the most controllable, universal and easy to use approach toward a broad set of 2D materials through consequent chemistries on cyanographene and on the prepared carboxy-, amino-, sulphydryl-, and hydroxy- graphenes.
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http://dx.doi.org/10.1021/acsnano.6b08449DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5371925PMC
March 2017

Electrocatalytic Nanostructured Ferric Tannates: Characterization and Application of a Polyphenol Nanosensor.

Chemphyschem 2016 Oct 19;17(20):3196-3203. Epub 2016 Aug 19.

Department of Comparative Biomedicine and Food Science, University of Padua, Agripolis, Viale dell'Università 16, Legnaro, 35020, PD, Italy.

A novel core-shell hybrid nanomaterial composed of peculiar maghemite nanoparticles (surface-active maghemite nanoparticles (SAMNs)) as the core and tannic acid (TA) as the shell was developed by self-assembly of ferric tannates onto the surface of SAMNs by simple incubation in water. The hybrid nanomaterial ([email protected]) was characterized by using UV/Vis, FTIR, and Mössbauer spectroscopies, magnetization measurements, and X-ray powder diffraction, which provide evidence of a drastic reorganization of the iron oxide surface upon reaction with TA and the formation of an outer shell that consists of a cross-linked network of ferric tannates. According to a Langmuir isotherm analysis, [email protected] offers one of most stable iron complexes of TA reported in the literature to date. Moreover, [email protected] was characterized by using electrical impedance spectroscopy, voltammetry, and chronoamperometry. The nanostructured ferric tannate interface showed improved conductivity and selective electrocatalytic activity toward the oxidation of polyphenols. Finally, a carbon-paste electrode modified with [email protected] was used for the determination of polyphenols in blueberry extracts by square-wave voltammetry.
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http://dx.doi.org/10.1002/cphc.201600718DOI Listing
October 2016

McRAPD unlike MALDI-TOF MS is a suitable candidate for routine discrimination of new Haemophilus influenzae strain acquisition in chronic obstructive pulmonary disease (COPD) and cystic fibrosis.

Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2016 Dec 6;160(4):503-511. Epub 2016 Oct 6.

Department of Microbiology, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic.

Background And Aims: Haemophilus influenzae new strain acquisition has been demonstrated to increase the relative risk of acute exacerbation fourfold in contrast to colonisation or chronic infection by the same strain in chronic obstructive pulmonary disease (COPD). Unfortunately, molecular typing techniques are not suitable for routine use due to cost, labour-intensity and need for special expertise. We tested two techniques potentially useful for routine typing, namely the newly available MALDI-TOF MS and the modified McRAPD compared to MLST as the gold standard.

Methods: In 10 patients (10.8%) suffering from COPD or cystic fibrosis, H. influenzae isolates were recovered repeatedly at different timepoints from the same patient during the study period. This allowed for thirteen pairwise comparisons of typing results in isolates recovered consecutively from the same patient to test the ability of the techniques to uncover new strain acquisition.

Results: MLST detected 9 cases of new strain acquisition among the 13 pairwise comparisons. However, MALDI-TOF MS reported all 13 pairs as different and thus new. In contrast, McRAPD was able to differentiate all the new strain acquisitions from pre-existing ones, both by visual inspection of melting profiles and by Relative Significant Difference values.

Conclusions: Unlike MALDI-TOF MS, McRAPD appears to be a suitable candidate for routine discrimination of new strain acquisitions because of its accuracy and, rapid, easy and economic performance.
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http://dx.doi.org/10.5507/bp.2016.050DOI Listing
December 2016

NAS agar is more suitable than McKay agar for primary culture of Streptococcus milleri group (SMG) fastidious bacteria, S. intermedius in particular.

Folia Microbiol (Praha) 2017 Jan 16;62(1):11-15. Epub 2016 Sep 16.

Department of Respiratory Medicine, University Hospital Olomouc, I. P. Pavlova 6, Olomouc, Czech Republic.

Streptococcus milleri group (SMG) is a group of three streptococcal species (S. anginosus, intermedius and constellatus) that act as opportunist pathogens, among others in cystic fibrosis. Due to their fastidious character, they are both difficult to cultivate and to differentiate from less pathogenic streptococcal species, therefore being most probably underdiagnosed. Semi-selective McKay agar and NAS agar were developed to facilitate SMG recovery from clinical samples; however, direct comparison of recovery rates has not been published yet. We tested the performance of both media on 123 patient samples and demonstrated general superiority of NAS agar for SMG recovery during primary cultivation convincingly. This observation was also confirmed by quantitative drop tests during subculture. Despite the undisputed overall superiority of NAS agar over McKay agar, a smaller fraction of strains grew better on McKay agar. Inter-strain differences were the most probable explanation. Therefore, when economic conditions are not limiting and maximum recovery rate is desirable, both plates are advised to be used in parallel for primary cultivation of clinical samples.
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http://dx.doi.org/10.1007/s12223-016-0470-yDOI Listing
January 2017

Advanced Sensing of Antibiotics with Magnetic Gold Nanocomposite: Electrochemical Detection of Chloramphenicol.

Chemistry 2016 Sep 16;22(40):14279-84. Epub 2016 Aug 16.

Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University in Olomouc, 17 Listopadu 1192/12, 771 46, Olomouc, Czech Republic.

The sensing and accurate determination of antibiotics in various environments represents a big challenge, mainly owing to their widespread use in medicine, veterinary practice, and other fields. Therefore, a new, simple electrochemical sensor for the detection of antibiotic chloramphenicol (CAP) has been developed in this work. The amplification strategy of the sensor is based on the application of magnetite nanostructures stabilized with carboxymethyl cellulose (Fe3 O4 -CMC) and decorated with nanometer-sized Au nanoparticles (NPs) (Fe3 O4 [email protected]). In this case, CMC serves as a stabilizing agent, preventing the aggregation of Fe3 O4 NPs, and hence, enabling the kinetic barrier for electron transport to be overcome, and the Au NPs serve as an electron-conducting tunnel for better electron transport. As a proof of concept, the developed nanosensor is used for the detection of CAP in human urine samples, giving a recovery value of around 97 %, which indicates the high accuracy of the as-prepared nanosensor.
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http://dx.doi.org/10.1002/chem.201602434DOI Listing
September 2016

Colloidal Surface Active Maghemite Nanoparticles for Biologically Safe Cr(VI) Remediation: from Core-Shell Nanostructures to Pilot Plant Development.

Chemistry 2016 Sep 16;22(40):14219-26. Epub 2016 Aug 16.

Department of Comparative Biomedicine and Food Science, University of Padua, Legnaro, 35020, Italy.

The present study is aimed at the exploration of achievable improvements for Cr(VI) ex situ and in situ water remediation by using novel naked colloidal maghemite (γ-Fe2 O3 ) nanoparticles (surface active maghemite nanoparticles, SAMNs). The reliability of SAMNs for Cr(VI) binding and removal was demonstrated, and [email protected](VI) complex was characterized, as well as the covalent nature of the absorption was unequivocally proved. SAMNs were structurally and magnetically well conserved after Cr(VI) binding. Thus, in consideration of their affinity for Cr(VI) , SAMNs were exploited in a biological model system, mimicking a real in situ application. The assay evidenced a progressive reduction of revertant colonies of Salmonella typhimurium TA100 strain, as maghemite nanoparticles concentration increased, till the complete suppression of Cr(VI) mutagen effect. Finally, an automatic modular pilot system for continuous magnetic removal and recovery of Cr(VI) from water is proposed. SAMNs, thanks to their colloidal, binding, and catalytic properties, represent a promising tool as a reliable nanomaterial for water remediation by Cr(VI) .
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http://dx.doi.org/10.1002/chem.201600544DOI Listing
September 2016

Performance of pyrosequencing versus MALDI-TOF MS in bacteria identification in chronic lung disease.

J Biol Methods 2016 13;3(4):e52. Epub 2016 Aug 13.

Department of Microbiology, Faculty of Medicine and Dentistry, Palacký University Olomouc, Hnevotinska 3, 779 00 Olomouc, Czech Republic.

Rapid identification of the etiological agent in bacterial infection is necessary for correct diagnosis and appropriate therapy. In general, identification of pure cultures of bacteria using conventional phenotyping techniques requires 4-24 hours. Recently available new molecular technologies offer the potential of same day species identification once pure culture is available. Our aim was to evaluate the performance of rDNA V1 hypervariable region pyrosequencing, and the whole cell MALDI-TOF MS protein profiling in routine species identification. During the period from June 2012 to June 2014, 1.140 pure culture isolates were recovered from 402 samples from 126 patients suffering cystic fibrosis, chronic obstructive pulmonary disease or bronchiectasis. All the isolates were subjected to species identification by both techniques. Unfortunately, pyrosequencing was able to reach the species level in 43.2% of isolates only, whereas MALDI-TOF was clearly superior with 96.8% respectively. The overall sensitivity values also clearly underlined the superiority of MALDI-TOF MS with 96.8% compared to 85.1% achieved by pyrosequencing. Generally, MALDI-TOF MS turned out to be the best suitable technique in routine bacterial identification, whereas pyrosequencing could be recommended as the method of choice particularly in situations where MALDI-TOF MS fails to identify rare species.
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http://dx.doi.org/10.14440/jbm.2016.125DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6706111PMC
August 2016

[Prolonged culture in a humid chamber increases the yields of pathogenic bacteria from the respiratory tract samples of patients suffering from cystic fibrosis].

Klin Mikrobiol Infekc Lek 2016 03;22(1):40-2

Department of Microbiology, Faculty of Medicine and Dentistry, Palacký University in Olomouc, Czech Republic, e-mail:

Current standards of care for cystic fibrosis (CF) patients lack unequivocal recommendations concerning the duration of primary culture of bacteriological samples. With the exception of Burkholderia cepacia (5 days), the minimum recommended duration of primary culture varies between 48 and 72 hours. Our aim was to evaluate the effect of an extended 10-day period of primary culture in a humid chamber in samples acquired from the respiratory tract of patients suffering from CF. Compared to standard culture, prolonged culture in a humid chamber yielded 1.85 times more isolates of pathogenic species in pharyngeal swabs (76 versus 41 isolates) and 1.4 times more isolates in sputum samples (116 versus 82), but only 1.14 times more isolates in nasal swabs (25 versus 22). Prolonged culture was most beneficial for Achromobacter spp. (6 versus 0), Stenotrophomonas maltophilia (16 versus 5) and Pseudomonas aeruginosa (69 versus 49), whereas there was little or no benefit at all for Staphylococcus aureus (87 versus 73) and Moraxella catarrhalis (10 versus 10). Therefore, prolonged culture in a humid chamber may definitely be recommended for pharyngeal swabs and sputum samples obtained from patients suffering from CF to achieve the maximum recovery rate of pathogenic bacteria, in particular non-fermenting Gram-negative rods.
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March 2016

[Diagnostics of cystic fibrosis in adults].

Vnitr Lek Spring 2016;62(5):360-4

Introduction: There is an increasing number of cystic fibrosis (CF) patients with the diagnosis established in adulthood worldwide.

Aim: To give an overview of our experience with the diagnostics of CF in adulthood in the Czech Republic.

Methods: CF patients with the diagnosis determined at the age 18 years during 2000-2014 period were selected from the Czech Registry of CF (www.cfregistr.cz). Demographic and clinical data were reported from medi-cal records at the time of diagnosis and as of 31st December 2014. Only those with two CF causing mutation or with one CF causing mutation together with sweat chloride concentration > 60 mmol/l were included in the study. The clinical presentation was compared with a control group consisting of homozygous F508del patients with the diagnosis established in childhood.

Results: 23 patients (16 men and 7 women) with the diagnosis determined at a mean age of 32.9 ± 8.5 years were included in the study. Presenting symptoms included bronchiectasis and/or haemoptysis in 12 cases, obstructive azoospermia in 7 cases and recurrent pancreatitis in 4 cases. When compared with the control group, the patients had higher age (38.6 ± 8.3 vs. 28.3 ± 4.7 years; p < 0.001), a lower concentration of sweat chloride (62 ± 23 vs. 90 ± 12 mmol/l; p < 0.001), less frequent airway infections with Pseudomonas aeruginosa and/or Burkholderia cepacia complex (4 vs. 12; p = 0.029), bronchiectasis (14 vs. 23; p = 0.001), exocrine pancreatic insufficiency (1 vs. 23; p < 0.001) and therapy with insulin (1 vs. 9; p = 0.01); on the contrary, pancreatitis was more frequent (6 vs. 0; p = 0.022).

Conclusion: Diagnosis of CF in adults should be considered in those with corresponding symptoms in respiratory, digestive and reproductive tract. Clinical presentation differs from classical CF in many parameters.

Key Words: adults - cystic fibrosis - diagnostics.
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June 2017

The Streptococcus milleri group in chronic obstructive pulmonary disease.

Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2016 Sep 21;160(3):378-84. Epub 2016 Apr 21.

Department of Microbiology, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic.

Background And Aims: S. anginosus, constellatus and intermedius, also known as the Streptococcus milleri group (SMG) are three streptococcal species more frequently detected in cases of invasive disease, abscesses and empyema in particular. Recent research suggests they play a role in exacerbations of cystic fibrosis (CF). Owing to poor recovery on standard culture media and difficult differentiation from non-pathogenic streptococci, SMG may be underdiagnosed in routine settings. We aimed to establish the incidence of SMG in chronic obstructive pulmonary disease (COPD) patients compared to CF patients and to examine possible links of SMG to exacerbations that plays a key role in progression of COPD.

Methods: Altogether, 90 respiratory tract samples of patients suffering from CF or COPD were examined during the period from July 2012 to December 2013. Semi-selective McKay agar was used for primary cultivation of SMG and MALDI TOF MS was used for species identification that was confirmed by biochemical profiling and specific PCR.

Results: We confirmed the presence of SMG in CF (17.6% incidence in adult patients) and newly established its presence in COPD (10.3% incidence). In COPD, SMG was detected in 4 cases of acute exacerbations, where no other bacterial pathogen was detected. In 3/4 cases, increased CRP level indicated bacterial infection as a cause of the exacerbation and in all 3 cases, patients recovered during antibiotic treatment.

Conclusions: Our data indicate SMG may act as opportunist pathogens able to cause exacerbations in COPD.
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http://dx.doi.org/10.5507/bp.2016.017DOI Listing
September 2016

Ternary Hybrid γ-Fe2 O3 /Cr(VI) /Amine Oxidase Nanostructure for Electrochemical Sensing: Application for Polyamine Detection in Tumor Tissue.

Chemistry 2016 05 8;22(20):6846-52. Epub 2016 Apr 8.

Department of Comparative Biomedicine and Food Science, University of Padua, Agripolis-Viale dell'Università 16, Legnaro, 35020 (PD), Italy.

Dichromate binds to surface-active maghemite nanoparticles (SAMNs) to form a stable core-shell nanostructures ([email protected](VI) ). The hybrid was characterized by Mössbauer spectroscopy, high-angle annular dark-field imaging, electron energy-loss spectroscopy, and electrochemical techniques, which revealed a strong interaction of dichromate with the nanoparticle surface. Electrochemical characterization showed lower charge-transfer resistance, better electrochemical performance, and more reversible electrochemical behavior with respect to naked SAMNs. Moreover, [email protected](VI) is an excellent electrocatalyst for hydrogen peroxide reduction. Furthermore, an enzyme, namely, bovine serum amine oxidase (BSAO: EC 1.4.3.6), was immobilized on [email protected](VI) by self-assembly to give a ternary hybrid nanostructured catalyst for polyamine oxidation ([email protected](VI) -BSAO). [email protected](VI) -BSAO was applied for the development of a reagentless, fast, inexpensive, and interference-free polyamine biosensor, which was successfully exploited for the discrimination of tumorous tissue from healthy tissue in human crude liver extracts.
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http://dx.doi.org/10.1002/chem.201600156DOI Listing
May 2016

A facile graphene oxide based sensor for electrochemical detection of neonicotinoids.

Biosens Bioelectron 2017 Mar 18;89(Pt 1):532-537. Epub 2016 Mar 18.

Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University in Olomouc, 17. listopadu 1192/12, 77146 Olomouc, Czech Republic. Electronic address:

The increasing use of neonicotinoids in systematic seed treatment to crops is a serious cause of pollution of water resources and environment. Consequently, food sources can get eventually contaminated. To this end, it is desirable to develop suitable and effective platforms in order to obtain low-cost and sensitive sensors for neonicotinoids detection. In this work, graphene oxide modified electrodes were used as highly efficient electrochemical sensors for detection of two common insecticides - thiamethoxam and imidacloprid. The proposed sensor responded linearly in the concentration range of 10-200µmolL for both analytes and the detection limits were determined as low as 8.3µmolL and 7.9µmolL for thiamethoxam and imidacloprid, respectively. Analytical performance was also evaluated on spiked water and honey samples.
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http://dx.doi.org/10.1016/j.bios.2016.03.039DOI Listing
March 2017

Validity of mesothelin in occupational medicine practice.

Int J Occup Med Environ Health 2016 ;29(3):395-404

Regional Public Health Authority of the Olomouc Region, Olomouc, Czech Republic.

Objectives: Malignant mesothelioma (MM) is the most serious asbestos-related disease. Its increasing incidence is alarming, suggesting the need for as early diagnosis as possible. This 4.5-year prospective longitudinal study aimed at assessing the benefit of measuring serum mesothelin as a marker for diagnosing malignant mesothelioma in individuals with previous occupational exposure to asbestos, as a part of their clinical follow-up care.

Material And Methods: The study comprised 309 participants (235 males, 74 females) with a mean age of 58.9 years (standard deviation (SD) = 9.8) and a mean duration of exposure to asbestos dust of 13.4 years (SD = 9.3). From 2009 to June 2013, all subjects were followed at a department of occupational medicine in Olomouc. Apart from the standard parts of medical examination (history, physical examination, simple chest radiographs and spirometry), the patients' serum mesothelin levels were determined by the Mesomark immunoenzymatic diagnostic assay. Statistical analysis of the validity of serum mesothelin level measurement was carried out with respect to the diagnosis of MM.

Results: Among the participants, 16 (5.2%) individuals (14 males and 2 females) were diagnosed with malignant mesothelioma. Based on the detected mesothelin levels, their validity for prediction of malignant mesothelioma was calculated as follows: sensitivity - 0.75, specificity - 0.962, positive predictive value - 0.706, negative predictive value - 0.969, positive and negative likelihood ratios - 19.95 and 0.26, respectively, and diagnostic odds ratio - 76.8, at a 95% confidence interval.

Conclusions: The high specificity was identified indicating the low false positivity as well. In the case of detecting elevated soluble mesothelin-related peptides (SMRP) levels in formerly asbestos-exposed individuals, the possibility of the presence of MM should be included into the clinical consideration. The high negative predictive value denotes a lower probability of the presence of MM in patients with normal SMRP levels but due to the limiting lower sensitivity this possibility cannot be entirely excluded.
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http://dx.doi.org/10.13075/ijomeh.1896.00637DOI Listing
January 2017

Citrinin mycotoxin recognition and removal by naked magnetic nanoparticles.

Food Chem 2016 Jul 17;203:505-512. Epub 2016 Feb 17.

Department of Comparative Biomedicine and Food Science, University of Padua, Italy; Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Palacký University in Olomouc, Czech Republic. Electronic address:

Citrinin is a nephrotoxic mycotoxin which can be synthesized by Monascus mold during the fermentation process in foods. Monascus, generally described as red mold, is a red-pigmented filamentous fungus attracting a great interest for the production of natural dyes and cholesterol-lowering statins. We individuated a specie of Monascus producing high amount of natural dyes. However, this high pigmentation was correlated with the production of citrinin. Peculiar magnetic nanoparticles, synthesized in-house and called "Surface Active Maghemite Nanoparticles" (SAMNs), are proposed as an efficient and reliable mean for citrinin removal from Monascus treated foods. The nanomaterial efficiency for citrinin binding was proved on Monascus suspensions, and [email protected] complex was characterized by Mӧssbauer spectroscopy and magnetization measurements, showing that SAMNs resulted structurally and magnetically well conserved after citrinin binding. SAMNs are excellent and stable magnetic nano-carrier for toxin removal, which can be applied in food industry.
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http://dx.doi.org/10.1016/j.foodchem.2016.01.147DOI Listing
July 2016

[Validity comparison of various biological samples from lower airway and their contribution for the detection of nosocomial pneumonia etiological agents].

Klin Mikrobiol Infekc Lek 2015 Mar;21(1):4-9

Palacky University, University Hospital and Faculty of Medicine, Department of Anaesthesiology and Intensive Care Medicine, Olomouc, Czech Republic, e-mail:

Background: The aim of the study was to compare the validity of bronchial secretion sampling and bronchoscopy-assisted protected specimen brushing (PSB) in patients with hospital-acquired pneumonia (HAP).

Materials And Methods: In patients with HAP, bronchial secretion samples (aspiration of lower airway secretions from an orotracheal tube with a suctioning catheter) and PSB (bronchoscopy-assisted sampling from the most affected area of the lung, verified by CT scan) were taken at the same time. Both samples were processed by semiquantitative routine microbiological techniques. Identification of microorganisms was performed by standard microbiological techniques using the MALDI-TOF automated system. For similarity or identity determination of bacterial isolates from bronchial secretion sampling and PSB, pulsed-field gel electrophoresis was used.

Results: Thirty patients were enrolled into the study. Thirty pairs of bronchial secretion samples and PSB samples were obtained and processed. The samples were positive in 23 patients (77 %) and 15 patients (50 %), respectively. In 15 cases, the same pathogen was determined in both samples, and in all those cases, the isolates were genetically identical.

Conclusion: The results of the study show that bronchial secretion samples analysis enabled identification of all pathogens that were identified by PSB. Given the high sensitivity of the bronchial secretion aspiration technique and genetic identity of isolates in both samples, bronchial secretion sampling may be recommended for determining HAP etiological agents as the samples are much easier to obtain from patients.
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March 2015
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