In this paper, the fuel properties of mixtures of diesel fuel and ethanol and diesel fuel and butanol in the ratio of 2.5% to 30% were investigated. The physicochemical properties of the blends such as the cetane number, cetane index, density, flash point, kinematic viscosity, lubricity, CFPP, and distillation characteristics were measured, and the effect on fuel properties was evaluated. These properties were compared with the current EN 590+A1 standard to evaluate the suitability of the blends for use in unmodified engines. The alcohols were found to be a suitable bio-component diesel fuel additive. For most physicochemical properties, butanol was found to have more suitable properties than ethanol when used in diesel engines. The results show that for some properties, a butanol-diesel fuel mixture can be mixed up to a ratio of 15%. Other properties would meet the standard by a suitable choice of base diesel.

• Klíčová slova
• CFPP, alternative fuel, biomaterials, butanol, cetane number, distillation, ethanol, lubricity, second generation,
• Publikační typ
• časopisecké články MeSH

Dicyclopentadiene (DCPD) modified unsaturated polyester resins (UPRs) are mostly used for hulls, decks, and bathroom facilities. Main advantages of these polymers over orthophthalic or isophthalic polyesters are their relatively low shrinking, reduced styrene emission, lower cost, and fast curing in thin layers. On the other hand, once cured, these materials are more brittle and have lower glass transition temperatures and lower chemical resistance due to their different chemical constitutions. DCPD UPRs with standard grades are usually produced with high-quality DCPD (over a 85% purity) using the so-called "water process", a synthesis consisting of two reaction steps. An adduct of maleic anhydride with DCPD is firstly formed with water, and then, it reacts with the other esterification monomers such as acids and glycols. DCPD raw materials used in this study were prepared by a unique distillation process developed by ORLEN Unipetrol and University of Chemistry and Technology, Prague. This technology allows producing a wide spectrum of DCPD quality by adjusting the content of another norbornene dimer: methyl dicyclopentadiene (MeDCPD). The influence of MeDCPD on unsaturated polyester properties was examined throughout this study. It has been discovered that in low concentrations, MeDCPD had a slight influence on flexural mechanical properties whereas its concentrations up to 65% led to a softer and brittle material. Nevertheless, by adjusting the unsaturation degree, it has been shown that MeDCPD may be successfully implanted in UPR formulation.

• Klíčová slova
• dicyclopentadiene, methyl dicyclopentadiene, unsaturated polyester, water process,
• Publikační typ
• časopisecké články MeSH

The aim of the article is to determine the properties of fuel mixtures of Fischer-Tropsch naphtha fraction with traditional gasoline (petrol) to be able to integrate the production of advanced alternative fuel based on Fischer-Tropsch synthesis into existing fuel markets. The density, octane number, vapor pressure, cloud point, water content, sulphur content, refractive index, ASTM color, heat of combustion, and fuel composition were measured using the gas chromatography method PIONA. It was found that fuel properties of Fischer-Tropsch naphtha fraction is not much comparable to conventional gasoline (petrol) due to the high n-alkane content. This research work recommends the creation of a low-percentage mixture of 3 vol.% of FT naphtha fraction with traditional gasoline to minimize negative effects-similar to the current legislative limit of 5 vol.% of bioethanol in E5 gasoline. FT naphtha fraction as a biocomponent does not contain sulphur or polyaromatic hydrocarbons nor benzene. Waste materials can be processed by FT synthesis. Fischer-Tropsch synthesis can be considered a universal fuel-the naphtha fraction cut can be declared as a biocomponent for gasoline fuel without any further necessary catalytic upgrading.

• Klíčová slova
• Fischer–Tropsch synthesis, alternative fuels, biocomponent, biofuel, biogasoline, bionaphtha, standardization, waste materials,
• Publikační typ
• časopisecké články MeSH

This paper focuses on the evaluation of the fuel properties of Fischer-Tropsch diesel blends with conventional diesel. Incorporating this advanced fuel into conventional diesel production will enable the use of waste materials and non-food materials as resources, while contributing to a reduction in dependence on crude oil. To evaluate the suitability of using Fischer-Tropsch diesel, cetane number, cetane index, CFPP, density, flash point, heat of combustion, lubricity, viscosity, distillation curve, and fuel composition ratios using multidimensional GC × GC-TOFMS for different blends were measured. It was found that the fuel properties of the blended fuel are comparable to conventional diesel and even outperform conventional fuel in some parameters. All measurements were performed according to current standards, thus ensuring the repeatability of measurements for other research groups or the private sector.

• Klíčová slova
• Fischer–Tropsch synthesis, alternative fuels, biodiesel, biofuel, standardization, waste materials,
• Publikační typ
• časopisecké články MeSH

Non-syndromic autosomal recessive hearing loss is an extremely heterogeneous disease caused by mutations in more than 80 genes. We examined Czech patients with early/prelingual non-syndromic, presumably genetic hearing loss (NSHL) without known cause after GJB2 gene testing. Four hundred and twenty-one unrelated patients were examined for STRC gene deletions with quantitative comparative fluorescent PCR (QCF PCR), 197 unrelated patients with next-generation sequencing by custom-designed NSHL gene panels and 19 patients with whole-exome sequencing (WES). Combining all methods, we discovered the cause of the disease in 54 patients. The most frequent type of NSHL was DFNB16 (STRC), which was detected in 22 patients, almost half of the clarified patients. Other biallelic pathogenic mutations were detected in the genes: MYO15A, LOXHD1, TMPRSS3 (each gene was responsible for five clarified patients, CDH23 (four clarified patients), OTOG and OTOF (each gene was responsible for two clarified patients). Other genes (AIFM1, CABP2, DIAPH1, PTPRQ, RDX, SLC26A4, TBC1D24, TECTA, TMC1) that explained the cause of hearing impairment were further detected in only one patient for each gene. STRC gene mutations, mainly deletions remain the most frequent NSHL cause after mutations in the GJB2.

• Klíčová slova
• hearing loss, next-generation sequencing, non GJB2 patients, non-syndromic hearing loss,
• MeSH
• dítě MeSH
• dospělí MeSH
• genetická predispozice k nemoci MeSH
• hluchota embryologie   genetika   patologie   MeSH
• kadherinové proteiny MeSH
• kadheriny genetika   MeSH
• konexin 26 genetika   MeSH
• lidé MeSH
• membránové glykoproteiny genetika   MeSH
• membránové proteiny genetika   MeSH
• mezibuněčné signální peptidy a proteiny genetika   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mutace genetika   MeSH
• myosiny genetika   MeSH
• nádorové proteiny genetika   MeSH
• nedoslýchavost epidemiologie   genetika   patologie   MeSH
• sekvenování exomu MeSH
• serinové endopeptidasy genetika   MeSH
• transportní proteiny genetika   MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Názvy látek
• CDH23 protein, human MeSH Prohlížeč
• GJB2 protein, human MeSH Prohlížeč
• kadherinové proteiny MeSH
• kadheriny MeSH
• konexin 26 MeSH
• LOXHD1 protein, human MeSH Prohlížeč
• membránové glykoproteiny MeSH
• membránové proteiny MeSH
• mezibuněčné signální peptidy a proteiny MeSH
• MYO15A protein, human MeSH Prohlížeč
• myosiny MeSH
• nádorové proteiny MeSH
• OTOF protein, human MeSH Prohlížeč
• OTOG protein, human MeSH Prohlížeč
• serinové endopeptidasy MeSH
• STRC protein, human MeSH Prohlížeč
• TMPRSS3 protein, human MeSH Prohlížeč
• transportní proteiny MeSH

BACKGROUND: The Roma are a European ethnic minority threatened by several recessive diseases. Variants in MANBA cause a rare lysosomal storage disorder named beta-mannosidosis whose clinical manifestation includes deafness and mental retardation. Since 1986, only 23 patients with beta-mannosidosis and biallelic MANBA variants have been described worldwide. RESULTS: We now report on further 10 beta-mannosidosis patients of Roma origin from eight families in the Czech and Slovak Republics with hearing loss, mental retardation and homozygous pathogenic variants in MANBA. MANBA variant c.2158-2A>G screening among 345 anonymized normal hearing controls from Roma populations revealed a carrier/heterozygote frequency of 3.77%. This is about 925 times higher than the frequency of this variant in the gnomAD public database and classifies the c.2158-2A>G variant as a prevalent, ethnic-specific variant causing hearing loss and mental retardation in a homozygous state. The frequency of heterozygotes/carriers is similar to another pathogenic variant c.71G>A (p.W24*) in GJB2, regarded as the most frequent variant causing deafness in Roma populations. CONLCUSION: Beta-mannosidosis, due to a homozygous c.2158-2A>G MANBA variant, is an important and previously unknown cause of hearing loss and mental retardation among Central European Roma.

• Klíčová slova
• Beta-mannosidosis, Ethnic-specific variant, Hearing loss, Mental retardation, Roma,
• MeSH
• beta-mannosidóza * MeSH
• etnicita MeSH
• hluchota * genetika   MeSH
• lidé MeSH
• menšiny MeSH
• nedoslýchavost * genetika   MeSH
• Romové * genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Slovenská republika epidemiologie   MeSH

Hereditary spastic paraplegia (HSP or SPG) is a group of rare upper motor neuron diseases. As some ethnically-specific, disease-causing homozygous variants were described in the Czech Roma population, we hypotesised that some prevalent HSP-causing variant could exist in this population. Eight Czech Roma patients were found in a large group of Czech patients with suspected HSP and were tested using gene panel massively parallel sequencing (MPS). Two of the eight were diagnosed with SPG11 and SPG77, respectively. The SPG77 patient manifests a pure HSP phenotype, which is unusual for this SPG type. Both patients are compound heterozygotes for two different variants in the SPG11 (c.1603-1G>A and del ex. 16-18) and FARS2 (c.1082C>T and del ex.1-2) genes respectively; the three variants are novel. In order to find a potential ethnically-specific, disease-causing variant for HSP, we tested the heterozygote frequency of these variants among 130 anonymised DNA samples of Czech Roma individuals without clinical signs of HSP (HPS-negative). A novel deletion of ex.16-18 in the SPG11 gene was found in a heterozygous state in one individual in the HSP-negative group. Haplotype analysis showed that this individual and the patient with SPG11 shared the same haplotype. This supports the assumption that the identified SPG11 deletion could be a founder mutation in the Czech Roma population. In some Roma patients the disease may also be caused by two different biallelic pathogenic mutations.

• Klíčová slova
• Czech Roma population, Hereditary spastic paraplegia, Prevalent variant, SPG11, SPG77,
• MeSH
• dítě MeSH
• dospělí MeSH
• etnicita genetika   MeSH
• fenylalanin-tRNA-ligasa genetika   MeSH
• genetická variace genetika   MeSH
• heterozygot * MeSH
• lidé středního věku MeSH
• lidé MeSH
• mitochondriální proteiny genetika   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• předškolní dítě MeSH
• proteiny genetika   MeSH
• rodokmen MeSH
• Romové etnologie   genetika   MeSH
• spastická paraplegie dědičná diagnóza   etnologie   genetika   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika etnologie   MeSH
• Názvy látek
• FARS2 protein, human MeSH Prohlížeč
• fenylalanin-tRNA-ligasa MeSH
• mitochondriální proteiny MeSH
• proteiny MeSH
• SPG11 protein, human MeSH Prohlížeč

INTRODUCTION: Hearing loss is the most frequent sensory disorder and is genetically extremely heterogeneous. By far the most frequent cause of nonsyndromic autosomal recessive hearing loss (AR-NSHL) are biallelic pathogenic mutations in the GJB2 gene causing DFNB1. The worldwide search for the second most common type of AR-NSHL took almost two decades. Recently reported alterations (mostly deletions) of the STRC gene, also named DFNB16, seem to be the second most frequent cause of AR-NSHL. Genetic testing of STRC is very challenging due to the highly homologous pseudogene. Anecdotal evidence from single patients shows that STRC mutations have their typical audiological findings and patients usually have moderate hearing loss. The aim of this study is to discover if audiological findings in patients with biallelic pathogenic mutations affecting STRC have the characteristic features and shape of audiological curves and if there are genotype/phenotype correlations in relation to various types of STRC mutations. METHODS: Eleven hearing loss patients with pathogenic mutations on both alleles of the STRC gene were detected during routine genetic examination of AR-NSHL patients. Audiological examination consisted of pure tone audiometry, stapedial reflexes, tympanometry and otoacoustic emission tests. RESULTS: The threshold of pure tone average (PTA) was 46 dB and otoacoustic emissions were not detectable in these DFNB16 patients. All patients were without vestibular irritation or asymmetry. CONCLUSION: Moderate sensorineural hearing loss is typical for DFNB16-associated hearing loss and there are no significant differences in audiological phenotypes among different types of mutations affecting STRC.

• Klíčová slova
• Audiological phenotype, Autosomal recessive nonsyndromic hearing loss, DFNB16, Genotype/phenotype correlation, STRC, Stereocilin,
• MeSH
• alely MeSH
• audiometrie MeSH
• dítě MeSH
• dospělí MeSH
• genetické asociační studie MeSH
• hluchota genetika   MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• konexiny genetika   MeSH
• lidé MeSH
• membránové proteiny genetika   MeSH
• mezibuněčné signální peptidy a proteiny genetika   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mutace genetika   MeSH
• percepční nedoslýchavost diagnóza   genetika   MeSH
• polymerázová řetězová reakce MeSH
• sekvenční delece genetika   MeSH
• sluchové testy MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• konexiny MeSH
• membránové proteiny MeSH
• mezibuněčné signální peptidy a proteiny MeSH
• STRC protein, human MeSH Prohlížeč

Fanconi anemia, complementation group D1 with bi-allelic FANCD1 (BRCA2) mutations, is a very rare genetic disorder characterized by early onset of childhood malignancies, including acute leukemia, brain cancer and nephroblastoma. Here, we present a case report of a family with 3 affected children in terms of treatment outcome, toxicity and characterization of the malignancies using comprehensive cytogenetic analysis. The first child was diagnosed with T-cell acute lymphoblastic leukemia when he was 11 months old. During chemotherapy, he suffered from repeated pancytopenia, sepsis and severe vincristine polyneuropathy, and 18 months after primary diagnosis, he succumbed to secondary acute monocytic leukemia. The second child was diagnosed with stage 2 triphasic nephroblastoma (Wilms tumor), when he was 3 years and 11 months old. During chemotherapy, he suffered from vincristine polyneuropathy. Currently, he is in complete remission, 29 months following the initial diagnosis. The third child was diagnosed with medulloblastoma with classical histology, when she was 4 years and 5 months old. After the first cycle of chemotherapy, she suffered from prolonged pancytopenia, sepsis and severe skin and mucosal toxicity. Six weeks after primary diagnosis, a first relapse in the posterior fossa was diagnosed, and at 7 and half months after primary diagnosis, a second relapse was diagnosed that led to the patient's death. Our case report underscores tumor heterogeneity, treatment toxicity and poor outcome in Fanconi anemia patients of complementation group D1.

• Klíčová slova
• BRCA2, FANCD1, Fanconi anemia, Leukemia, Medulloblastoma, Wilms tumor,
• MeSH
• Fanconiho anemie diagnóza   farmakoterapie   genetika   MeSH
• fenotyp MeSH
• hybridizace in situ fluorescenční MeSH
• imunofenotypizace MeSH
• jednonukleotidový polymorfismus MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• předškolní dítě MeSH
• protein BRCA2 genetika   MeSH
• protokoly protinádorové kombinované chemoterapie terapeutické užití   MeSH
• rodina MeSH
• ztráta heterozygozity MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH
• Názvy látek
• protein BRCA2 MeSH