BACKGROUND AND PURPOSE: The primary objective was to compare diffusion tensor imaging (DTI) scalar parameters of peripheral nerves between subjects with type 2 diabetes mellitus (T2DM) and those without diabetes. Secondarily, we aimed to correlate DTI scalar parameters with nerve morphometric properties. METHODS: Median, tibial, and sural nerves were harvested from 34 male cadavers (17 T2DM, 17 nondiabetic). Each nerve was divided into three segments. The initial segment was scanned using 9.4 Tesla MRI system (three-dimensional pulsed-gradient spin-echo sequence). DTI scalars were calculated from region-average diffusion-weighted signals. Second segment was optically cleared, acquired with optical projection tomography (OPT), and analyzed for morphometrical properties. Toluidine-stained sections were prepared from last segment, and axon- and myelin-related properties were evaluated. RESULTS: DTI scalar parameters of median and tibial nerves were comparable between the groups, while sural nerves of T2DM exhibited on average 41% higher mean diffusivity (MD) (p = 0.03), 38% higher radial diffusivity (RD) (p = 0.03), and 27% lower fractional anisotropy (FA) (p = 0.005). Significant differences in toluidine-evaluated parameters of sural nerves were observed between the groups, with a positive correlation between FA with fiber density (p = 0.0001) and with myelin proportion (p < 0.0001) and an inverse correlation between RD and myelin proportion (p = 0.003). OPT-measured morphometric properties did not correlate with DTI scalar parameters. CONCLUSIONS: High-field DTI shows promise as an imaging technique for detecting axonal and myelin-related changes in small sural nerves ex vivo. The reduced fiber density and decreased myelin content, which can be observed in T2DM, likely contribute to observed FA reduction and increased MD/RD.

• Klíčová slova
• diffusion tensor, fractional anisotropy, histology, magnetic resonance imaging, microscopy, optical projection tomography,
• MeSH
• diabetes mellitus 2. typu * diagnostické zobrazování   patologie   MeSH
• diabetické neuropatie diagnostické zobrazování   patologie   MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mrtvola * MeSH
• nervus medianus diagnostické zobrazování   patologie   MeSH
• nervus suralis * diagnostické zobrazování   patologie   MeSH
• nervus tibialis diagnostické zobrazování   patologie   MeSH
• reprodukovatelnost výsledků MeSH
• senioři MeSH
• senzitivita a specificita MeSH
• zobrazování difuzních tenzorů * metody   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Leishmaniasis is a group of neglected vector-borne diseases transmitted by phlebotomine sand flies. Leishmania parasites must overcome various defenses in the sand fly midgut, including the insects's immune response. Insect immunity is regulated by the ecdysone hormone, which binds to its nuclear receptor (EcR) and activates the transcription of genes involved in insect immunity. However, the role of ecdysone in sand fly immunity has never been studied. Phlebotomus perniciosus is a natural vector of Leishmania infantum; here, we manipulated its neuroendocrine system using azadirachtin (Aza), a natural compound known to affect ecdysone synthesis. METHODS: Phlebotomus perniciosus larvae and adult females were fed on food containing either Aza alone or Aza plus ecdysone, and the effects on mortality and ecdysis were evaluated. Genes related to ecdysone signaling and immunity were identified in P. perniciosus, and the expression of antimicrobial peptides (AMPs), EcR, the ecdysone-induced genes Eip74EF and Eip75B, and the transcription factor serpent were analyzed using quantitative polymerase chain reaction (PCR). RESULTS: Aza treatment inhibited molting of first-instar (L1) larvae to L2, with only 10% of larvae molting compared to 95% in the control group. Serpent and Eip74EF, attacin, defensin 1, and defensin 2 genes were downregulated by Aza treatment in larvae. Similarly, Aza-treated adult females also presented suppression of ecdysone signaling-related genes and the AMPs attacin and defensin 2. Notably, all gene repression caused by Aza was reversed by adding ecdysone concomitantly with Aza to the larval or female food, indicating that these genes are effective markers for ecdysone repression. CONCLUSIONS: These results highlight the critical role of ecdysone in regulating the development and immunity of P. perniciosus, which potentially could interfere with Leishmania infection.

• Klíčová slova
• Phlebotomus perniciosus, Antimicrobial peptides, Azadirachtin, Ecdysone,
• MeSH
• antimikrobiální peptidy genetika   farmakologie   MeSH
• ekdyson * MeSH
• hmyz - vektory účinky léků   genetika   parazitologie   imunologie   MeSH
• hmyzí proteiny genetika   metabolismus   MeSH
• larva * účinky léků   imunologie   genetika   MeSH
• limoniny * farmakologie   MeSH
• Phlebotomus * účinky léků   genetika   parazitologie   imunologie   MeSH
• shazování tělního pokryvu účinky léků   MeSH
• signální transdukce * účinky léků   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antimikrobiální peptidy MeSH
• azadirachtin MeSH Prohlížeč
• ekdyson * MeSH
• hmyzí proteiny MeSH
• limoniny * MeSH

Various strategies have been employed to improve the reliability of 2D, 3D, and co-culture in vitro models of nonalcoholic fatty liver disease, including using extracellular matrix proteins such as collagen I to promote cell adhesion. While studies have demonstrated the significant benefits of culturing cells on collagen I, its effects on the HepG2 cell line after exposure to palmitate (PA) have not been investigated. Therefore, this study aimed to assess the effects of PA-induced lipotoxicity in HepG2 cultured in the absence or presence of collagen I. HepG2 cultured in the absence or presence of collagen I was exposed to PA, followed by analyses that assessed cell proliferation, viability, adhesion, cell death, mitochondrial respiration, reactive oxygen species production, gene and protein expression, and triacylglycerol accumulation. Culturing HepG2 on collagen I was associated with increased cell proliferation, adhesion, and expression of integrin receptors, and improved cellular spreading compared to culturing them in the absence of collagen I. However, PA-induced lipotoxicity was greater in collagen I-cultured HepG2 than in those cultured in the absence of collagen I and was associated with increased α2β1 receptors. In summary, the present study demonstrated for the first time that collagen I-cultured HepG2 exhibited exacerbated cell death following exposure to PA through integrin-mediated death. The findings from this study may serve as a caution to those using 2D models or 3D scaffold-based models of HepG2 in the presence of collagen I.

• Klíčová slova
• HepG2 cells, collagen I, in vitro NAFLD models, integrin-mediated death, lipotoxicity, palmitate, α2β1 receptors,
• MeSH
• buněčná adheze * účinky léků   MeSH
• buněčná smrt účinky léků   MeSH
• buňky Hep G2 MeSH
• integrin alfa2beta1 metabolismus   MeSH
• integriny metabolismus   genetika   MeSH
• kolagen typu I * metabolismus   genetika   MeSH
• lidé MeSH
• nealkoholová steatóza jater metabolismus   patologie   MeSH
• palmitany toxicita   farmakologie   MeSH
• proliferace buněk * účinky léků   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• viabilita buněk * účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• integrin alfa2beta1 MeSH
• integriny MeSH
• kolagen typu I * MeSH
• palmitany MeSH
• reaktivní formy kyslíku MeSH

Perhalogenated closo-borates represent a new class of membrane carriers. They owe this activity to their chaotropicity, which enables the transport of hydrophilic molecules across model membranes and into living cells. The transport efficiency of this new class of cluster carriers depends on a careful balance between their affinity to membranes and cargo, which varies with chaotropicity. However, the structure-activity parameters that define chaotropic transport remain to be elucidated. Here, we have studied the modulation of chaotropic transport by decoupling the halogen composition from the boron core size. The binding affinity between perhalogenated decaborate and dodecaborate clusters carriers was quantified with different hydrophilic model cargos, namely a neutral and a cationic peptide, phalloidin and (KLAKLAK)2. The transport efficiency, membrane-lytic properties, and cellular toxicity, as obtained from different vesicle and cell assays, increased with the size and polarizability of the clusters. These results validate the chaotropic effect as the driving force behind the membrane transport propensity of boron clusters. This work advances our understanding of the structural features of boron cluster carriers and establishes the first set of rational design principles for chaotropic membrane transporters.

• Klíčová slova
• Boron, Cluster compounds, Membranes, Peptide delivery, Vesicles,
• MeSH
• biologický transport MeSH
• bor * chemie   metabolismus   MeSH
• boritany chemie   metabolismus   MeSH
• hydrofobní a hydrofilní interakce MeSH
• lidé MeSH
• sloučeniny boru chemie   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bor * MeSH
• boritany MeSH
• sloučeniny boru MeSH

After stroke rehabilitation, patients need to reintegrate back into their daily life, workplace and society. Reintegration involves complex processes depending on age, sex, stroke severity, cognitive, physical, as well as socioeconomic factors that impact long-term outcomes post-stroke. Moreover, post-stroke quality of life can be impacted by social risks of inadequate family, social, economic, housing and other supports needed by the patients. Social risks and barriers to successful reintegration are poorly understood yet critical for informing clinical or social interventions. Therefore, the aim of this work is to predict social risk at rehabilitation discharge using sociodemographic and clinical variables at rehabilitation admission and identify factors that contribute to this risk. A Gradient Boosting modelling methodology based on decision trees was applied to a Catalan 217-patient cohort of mostly young (mean age 52.7), male (66.4%), ischemic stroke survivors. The modelling task was to predict an individual's social risk upon discharge from rehabilitation based on 16 different demographic, diagnostic and social risk variables (family support, social support, economic status, cohabitation and home accessibility at admission). To correct for imbalance in patient sample numbers with high and low-risk levels (prediction target), five different datasets were prepared by varying the data subsampling methodology. For each of the five datasets a prediction model was trained and the analysis involves a comparison across these models. The training and validation results indicated that the models corrected for prediction target imbalance have similarly good performance (AUC 0.831-0.843) and validation (AUC 0.881 - 0.909). Furthermore, predictor variable importance ranked social support and economic status as the most important variables with the greatest contribution to social risk prediction, however, sex and age had a lesser, but still important, contribution. Due to the complex and multifactorial nature of social risk, factors in combination, including social support and economic status, drive social risk for individuals.

• Klíčová slova
• Machine learning, Prediction model, Rehabilitation, Reintegration, SHAP analysis, Social risk, Socioeconomic support, Stroke,
• MeSH
• dospělí MeSH
• ischemická cévní mozková příhoda * rehabilitace   psychologie   MeSH
• kvalita života MeSH
• lidé středního věku MeSH
• lidé MeSH
• rehabilitace po cévní mozkové příhodě * MeSH
• rizikové faktory MeSH
• senioři MeSH
• sociální opora MeSH
• socioekonomické faktory MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Time-resolved femtosecond-stimulated Raman spectroscopy (FSRS) provides valuable information on the structural dynamics of biomolecules. However, FSRS has been applied mainly up to the nanoseconds regime and above 700 cm-1, which covers only part of the spectrum of biologically relevant time scales and Raman shifts. Here we report on a broadband (~200-2200 cm-1) dual transient visible absorption (visTA)/FSRS set-up that can accommodate time delays from a few femtoseconds to several hundreds of microseconds after illumination with an actinic pump. The extended time scale and wavenumber range allowed us to monitor the complete excited-state dynamics of the biological chromophore flavin mononucleotide (FMN), both free in solution and embedded in two variants of the bacterial light-oxygen-voltage (LOV) photoreceptor EL222. The observed lifetimes and intermediate states (singlet, triplet, and adduct) are in agreement with previous time-resolved infrared spectroscopy experiments. Importantly, we found evidence for additional dynamical events, particularly upon analysis of the low-frequency Raman region below 1000 cm-1. We show that fs-to-sub-ms visTA/FSRS with a broad wavenumber range is a useful tool to characterize short-lived conformationally excited states in flavoproteins and potentially other light-responsive proteins.

• Klíčová slova
• femtosecond-stimulated Raman spectroscopy (FSRS), flavins, kinetic isotope effect (KIE), lifetime distribution analysis (LDA), light-oxygen-voltage (LOV) photosensors, maximum entropy method, photobiology, photochemistry, protein structural dynamics, time-resolved vibrational spectroscopy, transient visible absorption (visTA) spectroscopy,
• MeSH
• Ramanova spektroskopie * metody   MeSH
• spektrofotometrie infračervená MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has frequently been applied to the analysis of biomolecules. Its strength resides not only in compound identification but particularly in acquiring molecular profiles providing a high discriminating power. The main advantages include its speed, simplicity, versatility, minimum sample preparation needs, and a relatively high tolerance to salts. Other benefits are represented by the possibility of automation, high throughput, sensitivity, accuracy, and good reproducibility, allowing quantitative studies. This review deals with the prominent use of MALDI-TOF MS profiling in food and beverage analysis ranging from the simple detection of sample constituents to quantifications of marker compounds, quality control, and assessment of product authenticity. This review summarizes relevant discoveries that have been obtained with milk and milk products, edible oils, wine, beer, flour, meat, honey, and other alimentary products. Marker molecules are specified: proteins and peptides for milk, cheeses, flour, meat, wine and beer; triacylglycerols and phospholipids for oils; and low-molecular-weight metabolites for wine, beer and chocolate. Special attention is paid to sample preparation techniques and the combination of spectral profiling and statistical evaluation methods, which is powerful for the differentiation of samples and the sensitive detection of frauds and adulterations.

• Klíčová slova
• MALDI, adulteration, classification, differentiation, food, marker, mass spectrometry, milk, oil, protein,
• MeSH
• mléko * chemie   MeSH
• oleje MeSH
• reprodukovatelnost výsledků MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice metody   MeSH
• sýr * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• oleje MeSH

In the present study, the effect of material deposition at the elevated temperature baseplate on the microstructure and mechanical properties was investigated and correlated to the unique thermal history by using numerical simulation. Numerical results agreed well with the experimental results of microstructure and mechanical properties. Numerical results revealed a significant decrease in temperature gradient and a 40% decrease in thermal stress due to material deposition on the elevated temperature baseplate. The reduced thermal stress and temperature gradient resulted in coarser grain features, which in turn led to a decrease in hardness and tensile strength, especially for the bottom region near the baseplate. Meanwhile, no significant effect could be found for ductility. In addition, an elevated temperature baseplate promoted less heterogeneity in hardness and tensile properties along the building direction. The current work demonstrates a collective and direct understanding of the baseplate preheating effect on thermal stress, microstructure and mechanical properties and their correlations, which is believed beneficial for the better utilization of baseplate preheating positive effects.

• Klíčová slova
• austenite stainless steel 316L, baseplate heating, directed energy deposition, numerical modeling, tensile properties, thermal stress,
• Publikační typ
• časopisecké články MeSH

The advancement in additive manufacturing encourages the development of simplified tools for deep and swift research of the technology. Several approaches were developed to reduce the complexity of multi-track modeling for additive manufacturing. In the present work, a simple heat source model called concentrated heat source was evaluated for single- and multi-track deposition for directed energy deposition. The concentrated heat source model was compared with the widely accepted Goldak heat source model. The concentrated heat source does not require melt pool dimension measurement for thermal model simulation. Thus, it reduces the considerable time for preprocessing. The shape of the melt pool and temperature contour around the heat source was analyzed for single-track deposition. A good agreement was noticed for the concentrated heat source model melt pool, with an experimentally determined melt pool, using an optical microscope. Two heat source models were applied to multi-track 3D solid structure thermo-mechanical simulation. The results of the two models, for thermal history and residual stress, were compared with experimentally determined data. A good agreement was found for both models. The concentrated heat source model reported less than the half the computational time required for the Goldak model. The validated model, for 3D solid structure thermo-mechanical simulation, was used to analyze thermal stress evolution during the deposition process. The material deposition on the base plate at room temperature results in lower peak temperatures in the layers near the base plate. Consequently, the higher thermal stress in the layers near the base plate was found, compared to the upper layers during the deposition process.

• Klíčová slova
• additive manufacturing, concentrated heat source, directed energy deposition, goldak model, moving heat source, residual stress, thermal stress,
• Publikační typ
• časopisecké články MeSH

Additive manufacturing (AM) becomes a more and more standard process in different fields of industry. There is still only limited knowledge of the relationship between measured material data and the overall behaviour of directed energy deposition (DED)-processed complex structures. The understanding of the structural performance, including flow curves and local damage properties of additively manufactured parts by DED, becomes increasingly important. DED can be used for creating functional surfaces, component repairing using multiple powder feeders, and creating a heterogeneous structure with defined chemical composition. For thin parts that are used with the as-deposited surface, this evaluation is even highly crucial. The main goal of the study was to predict the behaviour of thin-walled structures manufactured by the DED process under static loading by finite element analysis (FEA). Moreover, in this study, the mechanical performance of partly machined and fully machined miniaturized samples produced from the structure was compared. The structure studied in this research resembles a honeycomb shape made of austenitic stainless steel AISI 316L, which is characterized by high strength and ductility. The uncoupled damage models based on a hybrid experimental-numerical approach were used. The microstructure and hardness were examined to comprehend the structural behaviour.

• Klíčová slova
• DED process, FEM, additive manufacturing, ductile damage, structure evaluation,
• Publikační typ
• časopisecké články MeSH