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The surface of any binary or multi-component nanocrystal has imperfections and defects. The number of surface defects depends both on the nature of the nanomaterial and on the method of its preparation. One of the possibilities to confine the number of surface defects is the epitaxial growth of the shell, which leads to a change in the physical properties while maintaining the morphology of the core. To form a shell of the desired thickness, an accurate calculation of the amount of its precursors is substantial to avoid the appearance of individual crystals consisting of the shell material. This study aimed to develop an effective calculation method for the theoretical amount of precursors required for the formation of a ZnS shell on the surface of a Cd0.25Zn0.75Se core, followed by the practical implementation of theoretical calculations and characterization of the prepared nanomaterials. This method allows the complete control of the masses and volumes of the initial reagents, which will in turn prevent undesirable nucleation of nuclei consisting of the shell material. In the synthesis of Cd0.25Zn0.75Se/ZnS core/shell quantum dots (QDs), the sources of chalcogens were substituted seleno- and thioureas, which are capable of not only supplanting modern toxic sources of sulfur and selenium but also allowing one to perform the controlled synthesis of highly photoluminescent QDs with a low number of surface defects. The result of this shell overcoating method was an impetuous augmentation in the photoluminescence quantum yield (PL QY up to 83%), uniformity in size and shape, and a high yield of nanomaterials. The developed synthetic technique of core/shell QDs provides a controlled growth of the shell on the core surface, which makes it possible to transfer this method to an industrial scale. Povrch jakéhokoliv binárního nebo multikomponentního nanokrystalu má nedokonalosti a defekty. Množství povrchových defektů závisí jak na druhu nanomateriálu, tak i na metodě jeho přípravy. Jednu z možností, jak omezit množství povrchových defektů je epitaxní růst vrstvy, který vede ke změně fyzikální vlastností, ale zároveň dochází k zachování morfologie jádra. Pro vytvoření obalu zamýšlené tloušťky je nezbytné provést přesné kalkulace množství prekurzoru, aby bylo zároveň zabráněno vzniku nových individuálních krystalů, které obsahují pouze materiál obalu. tato studie je zaměřená na vyvinutí efektivních metod kalkulací množství prekurzoru nezbytného pro formování obalu ZnS na povrchu Cd0.25Zn0.75Se jádra, následované praktickou implementací teoretických kalkulací a charakterizací připraveného nanomateriálu. Tato metoda umožňuje kompletní kontrolu nad množstvím a objemem vstupních reagentů, což má pak za následek prevenci nežádoucích nukleací materiálu obalu. Během syntézy core/shell kvantových teček Cd0.25Zn0.75Se/ZnS bylo použito různých zdrojů chalkogenů na bázi seleno- a thiomočovin, které jsou schopné nejen nahradit moderní toxické zdroje síry a selenu, ale i umožňují provést kontrolovatelnou syntézu vysoce luminiscenčních kvantových teček s malým množstvím povrchových defektů. Výsledkem této obalové metody je výrazné vylepšení fotoluminiscenčního kvantového výtěžku (až 83%) a uniformity velikosti, tvaru a vysokého výtěžku nanomateriálu. Vývoj syntézní techniky core/shell kvantových teček poskytuje vysoce kontrolovatelnou metodu růstu obalu na povrchu jádra, což ji dělá vhodnou pro transfer na průmyslovou aplikační úroveň.

Proper respiratory tract protection is the key factor to limiting the rate of COVID-19 spread and providing a safe environment for health care workers. Traditional N95 (FFP2) respirators are not easy to regenerate and thus create certain financial and ecological burdens; moreover, their quality may vary significantly. A solution that would overcome these disadvantages is desirable. In this study a commercially available knit polyester fleece fabric was selected as the filter material, and a total of 25 filters of different areas and thicknesses were prepared. Then, the size-resolved filtration efficiency (40–400 nm) and pressure drop were evaluated at a volumetric flow rate of 95 L/min. We showed the excellent synergistic effect of expanding the filtration area and increasing the number of filtering layers on the filtration efficiency; a filter cartridge with 8 layers of knit polyester fabric with a surface area of 900 cm2 and sized 25 × 14 × 8 cm achieved filtration efficiencies of 98 % at 95 L/min and 99.5 % at 30 L/min. The assembled filter kit consists of a filter cartridge (14 Pa) carried in a small backpack connected to a half mask with a total pressure drop of 84 Pa at 95 L/min. In addition, it is reusable, and the filter material can be regenerated at least ten times by simple methods, such as boiling. We have demonstrated a novel approach for creating high-quality and easy-to-breathe-through respiratory protective equipment that reduces operating costs and is a green solution because it is easy to regenerate.

Semiconductor quantum dots (QDs) have attracted great attention due to their unique optical and chemical properties. An increasing demand for size and shape uniformity of QDs, high quantum yield (QY) and photochemical stability can be resolved by synthetic methods. Here we report a study of the effect of the precursor ratios within the synthesis of a series of Cd-Zn-S QDs. Trisubstituted thiourea (N-phenylmorpholine-4-carbothioamide) as a new and environmentally friendly source of sulphur in the synthesis of Cd0.2Zn0.8S QDs (Cd, Zn : S molar ratios = 1 : 0.5; 1 : 1; 1 : 1.5; 1 : 2; 1 : 2.5) and CdxZn1-xS QDs (wherex= 0.1; 0.25; 0.5; 0.75; 0.9) has been investigated. It was determined that an increase in the molar ratio of trisubstituted thiourea to metals leads to the growth of QDs and as a consequence, to a small emission red shift in the visible region of the spectrum. However, no significant changes in the elemental ratio in the material were detected. It was found that with an excess of trisubstituted thiourea taken to the reaction, oleylamine (OAm) as a co-ligand replaces linoleic acid from the protective shell of the QDs. In the case of an increase of Cd content in the CdxZn1-xS QDs, a significant shift in the emission to the red region of the spectrum was observed with an increase in the size of the QDs while their shape was unchanged. Based on the XRD data, a gradual transition from a cubic to a hexagonal crystal structure was detected. The high quantum yield (70%), the narrow photoluminescence (PL) signal (FWHM < 31 nm) and the size uniformity of the obtained nanomaterials are promising features for production of highly sensitive sensors and LEDs. Polovodičové kvantové tečky (QDs) přilákaly velkou pozornost díky jejich unikátním optickým a chemickým vlastnostem. Rostoucí požadavky pro velikostní a tvarovou uniformitu QDs, vysoký kvantový výtěžek (QY) a fotochemická stabilita můžou být společně vyřešeny použitou syntetickou metodou. V tomto článku popisujeme efekt poměru prekurzorů během syntézy sérií QDs v systému Cd-Zn-S. Tri-substituovaná thiomočovina (N-feylmorfolin-4-karbotioamid) byla použita jakožto nový a enviromentálně příznivý zdroj síry pro syntézu kvantových teček Cd0.2Zn0.8S (Cd, Zn : S molární poměr = 1 : 0.5; 1 : 1; 1 : 1.5; 1 : 2; 1 : 2.5) a CdxZn1-xS Q (kde x = 0.1; 0.25; 0.5; 0.75; 0.9). Bylo zjištěno, že nárůst molárního poměru tri-substituované thiomočoviny vůči kovům vede nárůstu velikosti QDs a jakožto důsledek i k malému červenému posunu v jejich emisním spektru. nebyly však detekovány žádné výrazné změny v atomárním poměru materiálu částic. Dále byo zjištěno, že s rostoucím nadbytkem tri-substituované thiomočoviny v reakci dochází nahrazování linoleové kyseliny v ochranné slupce QDs za oleylamin (OAm). V případě nárůstu obsahu Cd v částicích CdxZn1-xS dochází k výraznému posunu emise do červené oblasti spektra spojeného s nárůstem velikosti částic, avšak změna jejich tvaru nebyla pozorována. Data z XRD potvrzují postupný přechod kubické krystalické struktury částic směrem ke struktuře hexagonální. Vysoký kvantový výtěžek (70%), úzké fotoluminiscenční spektrum (FWHM < 31 nm) a uniformita získaných nanočástic jsou slibnými vlastnostmi pro produkci vysoce citlivých senzorů a LED diod.

Solution processed thin chalcogenide films have attracted noteworthy attention due to the simplicity and thus low cost of applicable deposition techniques (e.g. spin-coating). In presented work we demonstrate the possibility to modify the thin films composition by altering the composition of source glass solution, which significantly improves tailoring potential of solution based thin films. Thin films of As30S70 composition of specular optical quality were prepared from As40S60 bulk glass and pure elemental sulfur by spin-coating method. The As40S60 source bulk glass is also commercially available as AMTIR-6. Optical properties, thickness, chemical resistance, structure and elemental composition of the thin films were studied in dependence on the annealing temperature. Results were compared with properties of thin films of the same As30S70 composition prepared by standard procedure from As30S70 bulk glass. Different thermo-induced structural transformations were observed in both sets of samples resulting in As30S70 thin films of very similar properties after thermal stabilization at 120 °C.

Presented work compares optical and chemical properties of As30S70, As35S65 and As40S60 amorphous chalcogenide thin films deposited by thermal evaporation and by spin-coating. Structural and compositional differences given by the chosen deposition technique and post deposition treatment were revealed by Raman spectroscopy and EDS. Applicability of studied thin films in electron beam lithography was investigated using both monoamine and diamine based developers. Thermally evaporated thin films exhibited negative etching contrary to the spin-coated films which showed positive etching. Studied thin films proved to be suitable positive and negative photoresists for both grey-scale and step-like lithography.

Quite recently, nanosized rare-earth (RE) fluorides have been gaining importance due to their ability to form nanocomposites that are capable to absorb ionizing radiation. The efficiency of these materials may vary under the influence of external factors and under the growing conditions of nanocrystals. In this paper a novel effective approach to the synthesis of CeF3 nanocrystals (NCs) with a high yield of the desired material was proposed. The developed approach allows different modifications within the synthesis, thereby making it possible to change the growth conditions of QDs. The main exchange reaction between cerium oleate and ammonium fluoride was carried out in a non-coordinating solvent 1-octadecene (ODE) diluted with an excess of oleic acid (OA). The influence of the reaction temperature on the nucleation and the formation of a nanocrystals was presented. The possibility of introducing Tb3+ (1-5%) into nanosized CeF3 at one of the lowest reaction temperatures (180 degrees C) was also studied. The introduction of Tb3+ into the CeF3 crystal lattice led to changes in the nanocrystal's structure, an increase in their size and also to the expected changes in the photoluminescence (PL) spectra. The prepared CeF3 and CeF3:Tb QDs were well dispersible in low-polar media, which makes them promising candidates for the role of active agents or wavelength shifters in the matrix of polymer scintillators. V nedávné době došlo k nárůstu významu nanokrystalů fluoridů dopovaných vzácnými zeminami díky jejich schopnosti formovat nanokompozity absorbující ionizující záření. Účinnost těchto materiálů se může lišit vlivem externích faktorů a podmínkami během růstu těchto nanokrystalů. V této práci prezentujeme nový přístup k syntéze nanokrystalů CeF3 s vysokým výtěžkem zamýšleného materiálu. Vyvinutý přístup umožňuje různou modifikaci během syntézy, a tedy ho dělá vhodným pro změnu růstových podmínek kvantových teček. Hlavní výměnná reakce mezi oleátem ceria a fluoridem amonným byla prováděna v nekoordinovaném rozpouštědle 1-oktadecenu (ODE) rozpuštěném v nadbytku olejové kyseliny (OA). Vliv reakční teploty na nukleaci a formování nanokrystalů jsou dále prezentovány v této práci. Byla taktéž studována možnost vnesení Tb3+ iontů (1-5%) do nanočástic TbF3 za jedné z nejnižších použitých reakčních teplot (180°C). Vnesení Tb3+ do CeF3 krystalové matrice vedlo ke změnám struktury nanokrystalu, nárůstu jejich velikosti a také k očekávané změne ve fotoluminiscečních spektrech. Připravené kvantové tečky CeF3 a CeF3:Yb byly dobře dispergovatelné v nízkopolárním mediu, což je dělá nadějnými kandidáty pro aktivní prvky pro změnu vlnových délek v matrici polymerních scintilátorů.

Solid solution AgInS2-ZnS nanostructures were prepared by reacting (Z)-1- (octadec-9-enyl)-3-phenylthiourea and 1-dodecanethiol with the corresponding metal linoleates. The combination of sulfur sources in modified ratios, which individually do not lead to significant results, resulted in the successful formation of nanorod-shaped heterostructures. The effect of sulfur source ratios on the structure, morphology, and optical properties of yellow-red emitting nanocrystals was systematically studied by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDS), X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM) analyzes. Nanocomposite materials based on polyvinyl toluene co-divinylbenzene (PVT-DVB) were investigated for each of the resulting nanostructures. It was demonstrated that even traces of nanomaterial (similar to 0.1 wt. %) provide a high photoluminescence quantum yield (PL QY up to 61.5%) of prepared nanocomposites. Pevné roztoky nanostruktur AgInS2-ZnS byly připraveny reakcí (Z)-1- (octadec-9-enyl)-3-fenylthimočoviny s odpovídajícími kovovými linoleáty. Kombinace zdrojů síry v modifikovaných poměrech, které samostatně nevedly k významným výsledkům, měly za následek úspěšnou syntézu heterostruktur ve formě nanotyčinek. Efekt poměrů různých zdrojů síry na strukturu, morfologii a optické vlastnosti žlutě-emitujících nanokrystalů byl systematicky studován metodami rentgenové difrakce (XRD), prvkové analýzy (EDS), rentgenové foto-elektronové spektroskopie (XPS) a skenovací transmisní elektronové mikroskopie (STEM). Nanokompozitní materiály založené na polyvinyl toluen co-divinylbenzenovém polymeru (PVT-DVB) byly studovány na všech připravených nanostrukturách. Bylo potvrzen, že i pouze stopy syntetizovaných nanomateriálů (cca. 0.1 hm.%) poskytnuly vysoký fotoluminiscenční výtěžek připravených nanokompozitů (až 61.5%)

In this work, the chalcogenide glass thin films of As-Ge-Sb-S system were prepared in specular optical quality by spin-coating from mixtures of separate As40S60 and Ge20Sb5S75 glass solutions. The five compositions were studied in total (0, 25, 50, 75 and 100 at.% of As40S60) to examine the possibility of deposition of quaternary chalcogenide glass thin films from mixture of simpler compositions solutions. The composition, organic residual content, structure, thickness, surface roughness, optical properties and chemical resistance of prepared films were studied in dependence on annealing temperature (up to 180C) and targeted composition. Thermally induced structural changes resulted in thin films with high optical quality and chemically stable polymerized glass structure. Physico-chemical properties of prepared mixed compositions thin films showed nearly linear combination of properties observed on As40S60 and Ge20Sb5S75 thin films. V této práci byly připraveny chalkogenidové vrstvy systému As-Ge-Sb-S ve spekulární optické kvalitě pomocí spin-coatingu směsí skelných roztoků As40S60 a Ge20Sb5S75. Celkem bylo studováno 5 složení (0, 25, 50, 75 a100 at.% As40S60) pro přezkoumání možnosti depozice kvarterních vrstev chalkogenidových skel ze směsí roztoků jednodušších složení. Chemické složení, obsah organických reziduí, struktura, tloušťka, drsnost, optické vlastnosti a chemická odolnost připravených vrstev byli studovány v závislosti na teplotě temperace (až do 180°C) a cíleném složení. Tepelně indukované strukturní změny měly vyústily v chemicky stabilní polymerní skelnou strukturu a vysokou optickou kvalitu připravených vrstev. Fyzikálně-chemické vlastnosti připravených směsných složení tenkých vrstev vykazovaly téměř lineární kombinaci vlastností pozorovaných na jednodušších tenkých vrstvách As40S60 a Ge20Sb5S75.

Chalcogenide As33S67 vitreous thin films prepared by thermal evaporation and spin-coating method from n-propylamine and n-hexylamine based solutions were structured using hot embossing technique with soft polydimethylsiloxane (PDMS) stamps. The influence of deposition method and conditions as well as thermal history of the samples was studied. Obtained results gave evidence that solution processed thin films can be structured at significantly lower temperatures in comparison with thermally evaporated thin films, even below Tg of the glass. Theory explaining observed phenomena based on the structural differences of solution processed and thermally evaporated thin films was proposed. Notable decrease in required embossing temperature of solution processed thin films will widen the range of chalcogenide glass compositions that can be structured by soft stamp hot embossing as well as the pool of usable substrates (such as substrates with lower temperature stability). Skelné chalkogenidové vrstvy As33S67 připravené metodami spin-coatingu a vakuového napařování z roztoků n-propylaminu a n-hexylaminu byly strukturovány s využitím metody hot embossing pomocí měkké polydimethylsiloxanové raznice (PDMS). Byl studován vliv depoziční metody, podmínek a teplotní historie vzorku. Získané výsledky prokázaly, že z roztoku připravené tenké vrstvy lze strukturovat při výrazně nižších teplotách v porovnáním s vakuově napařenými tenkými vrstvami, dokonce i při teplotách nižších, než Tg skla. Byla navržena teorie, vysvětlující toto nezvyklé chování, která byla založena na výrazném strukturním rozdílu mezi z roztoku deponovanými a vakuově napařenými tenkými vrstvami. Výrazný pokles v požadované embosovací teplotě v případě z roztoku připravených tenkých vrstev rozšiřuje množství složení chalkogenidových skel, které lze strukturovat metodou soft stamp hot embossingu, jakožto i mnosžví použitelných substrátů (např. substráty s nižší teplotní stabilitou).

Cardiac autonomic dysfunction has been reported in patients with long-standing multiple sclerosis (MS); however, data in early disease are limited. The present study was aimed at evaluating cardiac autonomic function in patients with early MS in the context of white matter metabolic status, which could potentially affect functions of the autonomic brain centers.Cardiac sympathetic and baroreflex cardiovagal responses to the Valsalva maneuver, orthostatic test, and the Stroop test were evaluated in 16 early, treatment-naïve patients with relapsing-remitting MS, and in 14 healthy participants. Proton magnetic resonance spectroscopic imaging (MRSI) of the brain was performed in eight of these MS patients and in eight controls.Valsalva maneuver outcomes were comparable between patients and controls. At baseline, norepinephrine levels were lower (p = 0.027) in MS patients compared to controls. The patients had higher heart rate (p = 0.034) and lower stroke volume (p = 0.008), but similar blood pressure, cardiac output and norepinephrine increments from baseline to 2 min of the orthostatic test compared to controls. MS patients and controls did not differ in responses to the Stroop test. MRSI showed lower total N-acetylaspartate/total creatine (p = 0.038) and higher myo-inositol/total creatine (p = 0.013) in MS lesions compared to non-lesional white matter.Our results show normal cardiac sympathetic and baroreflex cardiovagal function in MS patients with relapsing-remitting MS with lesions at the post-acute/early resolving stage.The study was registered at ClinicalTrials.gov under the Identifier: NCT03052595 and complies with the STROBE checklist for cohort, case-control, and cross-sectional studies.

Approximation techniques are useful in numerous engineering and non-engineering tasks. In electrical engineering and in the filter design in particular, approximation techniques allow to approximate in some sense a desired, usually an ideal, but not feasible frequency response of a filter. Among various approximations, polynomial approximations are very useful. The design of feasible linear digital filters with finite impulse response is based on them. There emerge two unique types among polynomial approximations, a maximally flat approximation and an equiripple approximation. We review here the polynomial equiripple approximation, its highlights, applications, history, evolution and latest achievements including open questions.

Background Inflammatory cytokines contribute to proatherogenic changes in lipid metabolism by reduction of HDL-cholesterol (HDL-C) levels, impairment of its antiinflammatory and antioxidant functions. Therefore, the protective actions of HDL-C can be limited in chronic inflammatory diseases such as multiple sclerosis (MS). The aim of this study was to assess the association between lipoprotein subfractions and inflammatory status in early stages of multiple sclerosis. Methods Polyacrylamide gel electrophoresis Lipoprint© System was used for lipoprotein profile analysis in 19 newly diagnosed MS patients, and in matched 19 healthy controls. Serum levels of interleukin (IL) 1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 (p70), IL-13, IL-17, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor, interferon-γ and TNF-α were measured by multiplex bead assay. Results Concentrations of the measured cytokines and lipoprotein subclasses were comparable between MS patients and controls. Male, but not female MS patients had significantly higher total HDL-C and small HDL-C subfraction than healthy controls. Large HDL-C negatively correlated with all measured cytokines except IL-17 in MS but not in controls. Intermediate HDL-C subfractions correlated positively with all measured cytokines except G-CSF in MS females but not in MS males or controls. Conclusion Our results of higher HDL-C and mainly its small HDL-C subfraction suggest that male MS patients are at higher risk of atherosclerosis and the subtle dyslipidemia is present in early stages of the disease. The correlations between specific HDL-C subfractions and the inflammatory cytokines demonstrate mutual links between systemic inflammation and lipid metabolism in MS. Trial registration ClinicalTrials.gov, Identifier: NCT 03052595 Registered on Feb 14, 2017.

Multiple sclerosis (MS) is a chronic inflammatory and demyelinating disease of the central nervous system. In addition to the genetic, epigenetic and immunological components, various other factors, e.g. unhealthy dietary habits, play a role in the MS pathogenesis. Dietary intervention is a highly appealing approach, as it presents a simple and relatively low risk method to potentially improve outcomes in patients with brain disorders in order to achieve remission and improvement of clinical status, well-being and life expectancy of patients with MS. The importance of saturated fat intake restriction for the clinical status improvement of MS patients was pointed for the first time in 1950s. Recently, decreased risk of first clinical diagnosis of CNS demyelination associated with higher intake of omega-3 polyunsaturated fatty acids particularly originating from fish was reported. Only few clinical trials have been performed to address the question of the role of dietary intervention, such is e.g. low saturated fat diet in MS treatment. This review summarizes current knowledge about the effect of different dietary approaches (diets low in saturated fat and dietary supplements such as fish oil, lipoic acid, omega-3 polyunsaturated fatty acids, seeds oils, high fiber diet, vitamin D, etc.) on neurological signs, patient’s well-being, physical and inflammatory status. So far the results are not conclusive, therefore much more research is needed to confirm and to understand the effectiveness of these dietary interventions in the long term and well defined studies.

Spectroscopic imaging ellipsometry was used to study 50 μm × 50 μm squares recorded into glassy As35S65 thin film by electron beam with different exposure doses. Optical constants (refractive index n and extinction coefficient k) of electron exposed areas were determined from imaging ellipsometric data recorded over a spectral range 390–800 nm. Complex dielectric permittivity of each of electron exposed square (glassy As35S65 with different electron exposure dose) was parametrized by a Tauc-Lorentz oscillator. Gradient optical model with the refractive index changing linearly within the layer thickness was used. Evaluation of parameters of Tauc-Lorentz oscillator revealed decrease of energy bandgap, increase of the refractive index in whole recorded spectra (more pronounced at the top of the film) and increase of extinction coefficient in the part of spectra where the material absorbs with the increasing electron exposure dose used for exposure of the squares. The decrease in local disorder with increasing electron exposure dose is quantified from the short wavelength absorption edge onset using a Mott-Davis model. The dependence of the parameters of Wemple-DiDomenico model for the transparent part of the optical constants spectra on electron exposure dose is shown. Thin film with recorded image was subsequently etched in amine based solution in aprotic solvent. While native film was fully etched off the remaining height of the exposed areas is increasing with the increasing electron exposure dose used. Knowledge of the changes of optical properties and etching rates induced by electron beam of different exposure doses can be used for fabricating of optical elements by high resolution electron beam lithography.

Objectives. Increased metabolic and cardiovascular morbidity has been reported in multiple sclerosis (MS) patients. Previously, we have found decreased insulin sensitivity and hyperinsulinemia in a group of newly diagnosed MS patients. We hypothesize that these features may be associated with an altered lipid profile and low, intermediate, or high density lipoprotein (LDL, IDL, HDL) subclasses accelerating atherosclerosis and thus contributing to the cardiovascular risk increase in these patients. Subjects and methods. In a group of 19 newly diagnosed untreated MS patients with previously found hyperinsulinemia and insulin resistance and a matched group of 19 healthy controls, the lipoprotein subclasses profile was determined. Polyacrylamide gel electrophoresis was used to separate and measure the LDL (large LDL and small dense LDL), HDL (large, intermediate and small), and IDL (A, B and C) subclasses with the Lipoprint© System (Quantimetrix Corporation, Redondo Beach, CA, USA). Results. No difference was found either in the conventional lipid or lipoprotein subclasses profile between the MS patients and healthy controls. We found an inverse association between the level of IDL-B with fasting insulin (r=–0.504, p=0.032), the insulin resistance estimated by homeo-static model assessment – insulin resistance (HOMA-IR) (r=–0.498, p=0.035), insulin response expressed as area under the curve (AUC; r=–0.519, p=0.027), and area above the baseline (AAB; r=–0.476, p=0.045) and positive association with insulin sensitivity estimated by insulin sensitivity index (ISI) Matsuda (r=0.470, 0.048) in MS patients, but not in healthy controls suggesting the first signs in lipoprotein subclasses profile change. Conclusions. Our data indicate that changes in lipoprotein profile and subclasses are preceded by insulin resistance and hyperinsulinemia in patients with newly diagnosed MS.

The aim of our prospective, interventional, pre-post, single arm study was to supplement the lack of knowledge of the effect of short-term Pilates intervention on selected blood parameters of healthy women. Female volunteers were recruited for 2-weeks Pilates intervention. Blood has been collected and anthropometric parameters were measured before and after exercise period (EP). Plasma insulin, cortisol, and dehydroepiandrosterone sulphate levels, erythrocyte antioxidant activity, glutathione levels, NK cytotoxicity and plasma cytokines were analysed. We found a decrease in erythrocyte antioxidant enzymes SOD and GPx activity; GSH levels; in the pro-inflammatory chemokine MCP-1 and trend to reduction in MIP-1β, PDGF and VEGF levels in plasma. NK cell cytotoxic activity increased after Pilates EP in the percentage of specific lysis at 25:1 effector: target (E:T) ratio and the same trend was observed at all E:T ratios as well as in the amount of lytic units per 107 cells. Our findings show that Pilates exercise may improve NK cell immune response and inflammatory milieu in plasma of healthy women.

Semiconductor quantum dots (QDs) with stable and wavelength-tunable photoluminescence (PL) are very promising emitters for various photonic and optoelectronic applications. In this paper, we describe a comparison of four synthetic approaches for highly photoluminescent blue-emitting Cd0.15Zn0.85S QDs. (Z)-1-(Octadec-9-enyl)-3-phenylthiourea, initially prepared from phenyl isothiocyanate and oleylamine, was used as the source of sulfur. Environmentally friendly and commercially available N,N′-disubstituted thiourea in combination with well-known methods is a suitable precursor for the highly reproducible synthesis and further large-scale production of ternary Cd0.15Zn0.85S QDs. This study was carried out to examine the mechanism of interaction between disubstituted thiourea and metal carboxylates in one of two tautomeric forms under the influence of oleylamine, which was taken as a base in the synthesis of the QDs by hot-injection and one-pot methods. Chemical and thermal decompositions of the QDs were performed to get information about the amount and composition of organic ligands in their shells. To elucidate the mechanisms of QD formation, the organic products were studied by NMR. Optical studies showed that the prepared nanomaterials exhibit narrow emission peaks with a full width half maximum (FWHM) of around 19–33 nm and a very small size of nanocrystals (1.59–3.53 nm).

This report summarize and compares with each other various methods for computing the symmetrical Zolotarev Polynomial of the first kind and its spectrum. Suitable criteria are suggested for the comparison. The best numerical stability shows the method employing Chebyshev polynomial recurrence. In case of the polynomial spectrum computation the best method is the one using the difference backward recursion introduced by M. Vlcek. Both methods are able to generate the polynomial of high degree up to, at least, 2000, using 32-bit IEEE floating point arithmetics.

Chalcogenide glass thin films of ternary As20Ge12.5S67.5 composition were prepared in specular quality using spin-coating technique from n-butylamine based glass solution. The content of organic residuals was notably reduced by post-deposition thermal treatment. The annealing process induced significant structural changes resulting in thin films with the structure close to the source bulk glass. The thickness of deposited thin films was decreasing with increasing annealing temperature. Contrary, the refractive index, optical bandgap, roughness and chemical stability were increasing. The experimental data also proved that deposited thin films were photo-sensitive as opto-physical properties and chemical resistance were changed after UV light exposure. The exposed thin films annealed bellow 90 °C were etched slower than unexposed ones (negative etching) and the thin films annealed above 90 °C were etched faster (positive etching).

This brief introduces a novel closed-form method for a robust evaluation of partial impulse responses in a cascade structure of narrow equiripple (ER) bandpass finite-impulse-response filters. The approach presented here is based on a generating polynomial for an ER approximation. The importance of the method is seen in its inherent robustness, which significantly outperforms the existing numerical approach. Consequently, much longer filters can be represented in their cascade form. Two examples demonstrate the functionality, performance, and usefulness of the method, as well as its superiority in terms of robustness over the existing approach.

Compositional dependences of glass transition temperature T g , optical properties and structure of As 35 S 65 − x Se x thin films are studied in this paper. Changes of studied optical properties induced either by exposure to polychromatic light or annealing are also studied together with in-situ kinetics measurement. It was found that in comparison with annealing exposure to polychromatic light induces more significant changes in optical properties as a result of more significant internal structural changes which were confirmed by Raman spectroscopy.

Chalcogenide glass (ChG) thin films prepared by solution based deposition technique offer important advantages over vacuum deposited films, which are useful for many applications especially in infrared optics. Their fabrication, which comprises dissolving the ChG in volatile organic solvent and then depositing thin film by spin coating the solution, is simpler and significantly cheaper. However, contaminants from the solvent are incorporated. The residual organic content in the films is significantly reduced by appropriate thermal treatment. This work reports the influence of specific annealing conditions and UV light exposure on the structure, opto-physical and chemical properties of As30S70 spin-coated ChG films. The results show increase in refractive index with increasing annealing temperature, whereas the thickness and optical bandgap decrease. The UV exposed regions of the samples exhibit positive etching in amine based solvents. The HS-LEIS spectroscopy is used to determine the elemental concentration profile of annealed thin film, which shows almost stable As/S ratio with composition close to that of the source bulk glass. Thus UV light induced structural changes and the mechanism of selective etching are proposed.

Photostructural transformations within AsxS100-x (x = 30, 33, 35, 40) thin films upon exposure to LED light of different wavelengths, in both air and argon environments have been studied by high resolution XPS, Raman spectroscopy and LEIS methods. These complementary results show that light of energies close to the band gap does not modify chemical composition of the surface, but induces simple photopolymerization reactions. Superbandgap UV light, however, significantly increases S/As ratio on the surface due to formation of S-rich layer under both environmental conditions. It is proposed that photovaporization of both oxide and non-oxide cage-like molecules is responsible for the observed effect.

Nucleation and growth of quantum dots (QDs) in solution are mainly controlled by the kinetic and thermal modes of the reaction process. By influencing any of them, the properties of the final nanocrystals can be tuned. The influences of temperature and chemical nature of starting materials on nucleation and, as a consequence, on the structure and optical properties of Cd0.15Zn0.85S QDs have been systematically investigated by one-pot and hot-injection methods. All reactions were performed in organic disperse medium using N,N'-disubstituted and N,N',N'-trisubstituted thioureas (TU) as a new sources of sulfur. In addition to environmental friendliness, each of them has a number of unique chemical properties. The effect of the substituents' nature in thioureas on the morphology, size and optical properties of synthesized QDs has been studied. The strong correlation between the metal ratios taken to the reaction and elemental analysis (EDS) results for all obtained Cd0.15Zn0.85S QDs was found. However, prepared nanomaterials have different size (2.9-4.6 nm) and morphology. The optical features have also changed under the various thermal conditions. Especially, the changes in the photoluminescence spectra of QDs synthesized with different thioureas are noticeable. Highly photoluminescent (photoluminescence quantum yield PL QY up to 67%), morphologically and structurally homogeneous blue-emitting Cd0.15Zn0.85S QDs were obtained. Nukleace a růst kvantových teček (QDs) v roztoku jsou primárně kontrolovány kinetikou a tepelným modem reakčního procesu. Ovlivňováním každého z nich lze upravovat finální vlastnosti připravených částic. Ve článku byl systematicky studován vliv teploty a chemické podstaty startovních materiálů na nukleaci a jejím důsledkem na strukturu a optické vlastnosti QDs Cd0.15Zn0.85S, připravených pomocí metody horké injektáže prekurzorů v jednom reakčním kroku. Všechny reakce byly prováděny v organickém disperzním médiu pomocí N,N'-disubstituovaných a N,N',N'-trisubstituovaných thiomočovin (TU) jakožto nového zdroje síry. Kromě enviromentálně příznivého přístupu mají navíc každá z nich mnoho dalších unikátních chemických vlastností. Byl studován vliv druhu substituentů v thiomočovinách na morfologii, velikost a optické vlastnosti syntetizovaných kvantových teček. Byla nalezena silná korelace mezi poměru kovových prvků vložených do reakce a výsledků prvkové analýzy (EDS) pro všechny připravené kvantové tečky Cd0.15Zn0.85S. Připravené materiály měly však rozdílnou velikost částic (2.9-4.6 nm) a morfologii. Optické vlastnosti se taktéž změnili vlivem rozdílných tepelných podmínek. Zvláště pak byly patrné změny ve fotoluminiscenčních spektrech syntetizovaných QDs vlivem rozdílných použitých thiomočovin. Uvedenými reakcemi byly připraveny vysoce luminiscenční (kvantový výtěžek až 67%), morfologicky a strukturálně homogenní modře emitující kvantové tečky Cd0.15Zn0.85S.

Solution processed thin chalcogenide films gain attention due to their interesting optical properties and simplicity of the deposition. The influence of the aliphatic chain length in primary amines used for As33S67 thin films deposition by spin-coating and their subsequent characterization had been studied in this paper, particularly films prepared from solutions based on n-propylamine, n-butylamine, n-pentylamine and n-hexylamine were investigated. As-prepared thin films were annealed at temperatures below glass Tg. Results gave evidence that variety in physical and chemical properties of studied amines influences required conditions of deposition process of the thin film only (such as source glass dissolution time, thin film thickness, thickness shrinkage). The structure, optical properties, surface roughness, organic residual content and chemical resistance of deposited thin films are not significantly influenced by used amine but mostly by the post-deposition annealing temperature. Thin films composition remains uninfluenced by neither used amine nor the annealing temperature. Z roztoku deponované tenké vrstvy chalkogenidových skel získávají pozornost díky jejich zajímavým optickým vlastnostem a jednoduchostí depozice. Vliv délky alifatického řetězce primárních aminů použitých pro depozici tenkých vrstev As33S67 pomocí spin-coatingu a jejich následná charakterizace byli náplní tohoto článku, zejména pak filmy připravené z roztoků založených na n-propylaminu, n-butylaminu, n-pentylaminu and n-hexylaminu. Čerstvě připravené tenké vrstvy byly temperovány na teploty pod Tg použitého skla. Výsledky potvrdily, že množství fyzikálních a chemických vlastností studovaných aminů ovlivňuje pouze potřebné podmínky pro depozici vrstev (jako jsou doba rozpouštění původního objemového skla, tloušťka tenké vrstvy a jejich ztenčování). Struktura, optické vlastnosti, drsnost povrchu, obsah organických reziduí a chemická odolnost deponovaných vrstev nejsou výrazně ovlivněny použitým aminem, ale hlavně post-depoziční teplotou temperace. Složení tenkých vrstev zůstává neovlivněno jak použitým aminem, tak i teplotou temperace.

The Ge25Se75, Ge20Se80 and Ge15Se85 thin films were deposited in specular optical quality from n-propylamine - methanol solvent mixture by spin-coating technique. As-prepared solution processed thin films were thermally stabilized to reduce the content of organic solvent residuals and optical properties, surface topography, composition, structure and chemical resistance of prepared Ge-Se thin films were studied in dependence of annealing temperature. Suitable thermal stabilization temperatures were found for each studied chalcogenide glass composition with respect to maintaining of thin films’ low surface roughness and targeted elemental composition. Stabilized thin films exhibited high refractive index, high chemical resistance, low surface roughness and structure close to source bulk glasses. The experiments proved that used n-propylamine - methanol solvent offered suitable way for preparation of high optical quality Ge-Se thin films by solution based deposition route. Tenké vrstvy Ge25Se75, Ge20Se80 a Ge15Se85 byly deponovány ve spekulární optické kvalitě z n-propylamin-metanolové směsi rozpouštědel pomocí metody spin-coating. Čerstvě připravené tenké vrstvy byly tepelně stabilizovány pro redukci obsahu zbytků organických rozpouštědel a optické vlastnosti, topografie povrchu, složení, struktura a chemická odolnost připravených tenkých vrstev Ge-Se byly studovány v závislosti na teplotě temperace. Byly nalezeny vhodné teploty temperace pro každé studované složení chalkogenidového skla s ohledem na zachování nízké drsnosti vrstev a jejich cíleného složení. Stabilizované tenké vrstvy vykazovaly vysoký index lomu, vysokou chemickou odolnost, nízkou drsnost povrchu a strukturu blízkou struktuře výchozího objemového skla. Experimenty prokázaly, že použití směsi n-propylamin-metanolové směsi rozpouštědel nabízí vhodný způsob přípravy tenkých vrstev systému Ge-Se ve vysoké optické kvalitě s využití, roztokové depoziční cesty.

Higher testosterone levels in males have previously been linked to decreased stress reactivity, but in other cases, testosterone has been reported to increase the stress response. We addressed these inconsistencies in a placebo-controlled single-dose testosterone administration study, in which 120 male participants were randomly assigned to undergo a cold-pressor test (CPT, a non-social somatic stressor), a socially evaluated cold-pressor test (SECPT, a social-somatic stressor), or a lukewarm water test (LWT, a non-stressful control condition). Throughout the experiment, blood pressure and interbeat intervals were measured continuously, and saliva samples for hormonal analyses were taken repeatedly at predefined time points. When comparing the groups treated with placebo, the SECPT elicited a larger increase in the systolic blood pressure than CPT, in agreement with previous studies. However, testosterone administration altered this pattern. Compared to placebo, testosterone increased systolic blood pressure during the CPT, whereas the opposite effect was found during the SECPT. Cortisol reactivity was not affected by testosterone administration. The CAG repeat polymorphism of the androgen receptor gene was unrelated to the effects of testosterone on the stress response, but it was correlated with blood pressure across the whole sample. Our findings demonstrate that testosterone's effects on the stress response are dependent on the social context. Testosterone's ability to flexibly influence the response to stressors may be an important mechanism through which the hormone promotes adaptive behavior. Our results are also in line with research showing that testosterone decreases social anxiety and suggest it may help to modulate the effects of stress in socially challenging situations.

The standard therapy for malignant primary bone tumors such as osteosarcoma involves major surgeries. For tumors located in difficult regions such as the pelvis, surgical intervention could lead to serious side effects for example loss of a limb and/or function, loss of bowel, bladder and sexual function as well as problems with wound healing and surgical complications. Therefore, exploring other approaches that can improve or complement current surgical techniques is important. Hence, sensitizing primary bone tumors to radiation could offer an additional strategy that could complement surgery and significantly improve survival and quality of life. Gold nanoparticles (AuNPs) have been shown to enhance radiosensitivity by increasing the local dose of radiation inside tumors. Therefore, the referred procedure of preparation and functionalization of gold nanoparticles may be used for investigation whether DNA repair inhibition in the presence of AuNPs leads to an effective radiosensitizing strategy for primary bone tumor cells and explore the mechanism of how this may be happening. In our work, we prepared gold nanoparticles and verified the relation between the size of the AuNPs and their uptake in tumor 143B cells and also investigated whether the optimal size of the AuNPs should not be smaller than the size of nuclear envelope pores (20-50 nm). Hence, two different AuNPs systems were prepared: the first one with AuNPs core size of about 5 nm (BS) and the second one with AuNPs core size of about 50 nm (ZA). For cellular AuNPs uptake enhancement, we functionalized the AuNPs with signaling peptides. For this purpose we prepared PEG-coated AuNPs functionalized with signal peptides for targeted transport into the cytoplasm (CPP) and into the cell nucleus (CPP + NLS). The toxicity of the AuNPs systems was assessed by MTS assay. We prepared stable functionalized AuNPs systems of both sizes. With the functionalizing of the AuNPs using signal peptides (CPP, NLS), the AuNPs penetrated into the cell nucleus. The referred procedure of preparation and functionalization of gold nanoparticles may be used for investigating inhibition of DNA repair in the presence of AuNPs and it could lead to new understanding in overcoming radioresistance in primary bone tumor cells. Standardní terapie pro zhoubné primární kostní nádory jako např. osteosarkom zahrnují závažné operace. Pro nádory nacházející se v obtížných oblastech, jako je pánev, operační intervence můžou vést k závažným vedlejším efektům, jako je například ztráta končetiny nebo její funkce, ztráta střeva, žaludku a sexuálních funkcí, jakožto i problémy s hojením ran a další operační komplikace. Proto výzkum dalších přístupů je důležitý pro vylepšení nebo doplnění současných operačních technik. Z tohoto důvodu může senzibilizace primárních kostních nádorů vůči radiaci nabídnout další strategický přístup, který může sloužit jako doplněk operaci a výrazně vylepšit přežití a kvalitu života pacientů. Zlaté nanočástice (Au NPs) vykazují zvýšenou radiosenzitivitu pomocí zvýšení lokální dávky radiace v nádoru. V naší práci jsme připravili zlaté nanočástice a ověřili spojitost mezi velikostí AuNPs a jejich absorpcí do buněk 143B a také jsme zkoumali, zda optimální velikost AuNPs nebude menší než velikost pórů obalu (20-50 nm). Proto byly připraveny dva systému AuNPs: první s velikostí jader AuNPs okolo 5 nm (BS) a druhý s velikostí jádra kolem 50 nm (ZA). Pro vylepšení buněčného příjmu AuNPs jsme funkcionalizovali částice signálními peptidy. Pro tento účel jsme připravili AuNPs obalené PEG, které jsme následně funcionalizovali pro cílený transport do cytoplasmy (CPP) a do jádra buňky (CPP + NLS). Toxicita onou systémů AuNPs byla posouzena MTS testem. Připravili jsme stabilní funkcionalizované AuNPs obou velikostí. Pomocí funcionalizace AuNPs pomocí signálních peptidů (CPP, NLS), částice úspěšně penetrovali do jádra buňky. Popsaná procedura přípravy a funkcionalizace zlatých nanočástic může bát použita pro výzkum inhibitorů opravy DNA za přítomnosti AuNPs a může vést k novému porozumění překonání radioodolnosti buněk v primárních kostních nádorech.

Multiple sclerosis (MS) is a chronic inflammatory autoimmune and neurodegenerative disease of the central nervous system (CNS) typically affecting young adults. Although the pathogenesis of MS is not fully understood, there is evidence to suggest that inflammation-induced oxidative stress can play a role in demyelination and axonal damage. Oxidative stress also participates in the pathogenesis of endothelial dysfunction and atherogenesis. Data from large epidemiological studies showed a higher risk of vascular events in MS patients. The aim of our study was to analyse the presence of oxidative stress and its association with the parameters of subclinical atherosclerosis in the early stages of MS.We compared 13 newly diagnosed MS patients with a group of 13 healthy age- and BMI-matched controls. Blood samples were measured for total antioxidant activity using TEAC assay. Endothelial function, expressed as reperfusion hyperaemia index (RHI) and arterial stiffness, expressed as augmentation index standardized to a pulse of 75/min (AI@75) were assessed using peripheral arterial tonometry.MS patients had significantly lower TEAC compared to controls [0.8 (0.4-2.4) vs. 1.2 (0.6-3.8) mmol/l; p=0.004]. The frequency of increased arterial stiffness (61.6% vs. 30.8%) and endothelial dysfunction (46.2% vs. 38.5%) was comparable in MS patients and in controls. There was no significant association between TEAC, increased arterial stiffness or endothelial dysfunction in patients and controls.Our study showed decreased antioxidant capacity in newly diagnosed MS patients compared to controls. We failed to find association of subclinical atherosclerosis with oxidative stress in newly diagnosed MS.

Objective Atherogenic dyslipidemia is a cardinal feature of obesity and the metabolic syndrome, which increases the risk of cardiovascular diseases. Many interventional studies, describing the influence of weight loss on cardiometabolic risks, are bariatric surgery studies. The aim of our study was to analyze the effect of intensive lifestyle changes on LDL- and HDL-cholesterol subfractions and cardiometabolic risk factors in obese subjects. Methods A group of 41 patients with obesity (11M/30F; 44.1 ± 12.4 years; BMI 30.2 ± 6.3 kg/m2) participated in an 8-week weight loss interventional program (NCT02325804), consisting of caloric intake reduced by 30% and physical activity (150 min/week). Insulin sensitivity was evaluated according to the homeostasis model assessment of insulin resistance (HOMA-IR) and physical fitness was measured using bicycle ergometry. Lipid subfractions were measured using the Lipoprint system (Quantimetrix Corp., CA, USA). Results After the intervention, body weight was reduced by 5.4 ± 4.5 kg, as well as body fat mass and waist circumference. Physical fitness improved, systolic and diastolic blood pressure as well as heart rate decreased after the intervention. Insulin sensitivity improved after the intervention. Total, LDL, HDL cholesterol, as well as triglycerides decreased after the intervention. Regarding the lipoprotein subfractions, LDL2 and small HDL subfractions decreased, while others have not changed. Conclusion Eight weeks of diet and physical activity intervention led to weight and fat mass loss and induced improvement of insulin sensitivity, as well as atheroprotective changes of lipid profile. However, the weight loss associated changes in cholesterol subfractions as cardiovascular risk biomarkers deserve further studies.

Thermally evaporated chalcogenide glass thin films are known to be highly photosensitive revealing both metastable and transient photoinduced changes of optical transmission at the fundamental absorption edge region. In-situ kinetics of metastable photobleaching and transient photodarkening as well as following light-off relaxations for as-deposited GeSe2 thin films were studied and fitted with the stretched exponential function. Dependences of kinetic parameters beta and tau a on film thickness, temperature, sample prehistory and wavelength of light irradiation were analyzed. The obtained results were discussed within current approaches to mechanisms of photoinduced kinetic phenomena and structural relaxation in glasses. Vakuově napařené tenké vrstvy chalkogenidových skel jsou známé pro svoji vysokou fotocitlivost odhalující metastabilní a přechodné fotoindukované změny optické propustnosti v regionu fundamentální absorpční hrany. Byly studovány a fitovány n-situ kinetiky metastabilního fotosvětlání a přechodného fototmavnutí čerstvě deponovaných vrstev GeSe2, jakožto i relaxace při vypnutí zdroje expozice. Byla analyzována závislost parametrů kinetiky beta a tau na tloušťce, teplotě, historii vzorku a vlnové délce použitého záření. Získané výsledky byly diskutovány v rámci současných přístupů k mechanismům fotoindukovaných jevů a strukturální relaxace ve sklech.

Spectroscopic ellipsometry study on spin-coated non-toxic Ge25S75 thin films annealed at different temperatures were conducted. Multi sample analysis with two sets of samples spin-coated onto soda-lime glass and onto silicon wafers was utilized. Optical constants (refractive index n and extinction coefficient k) of these films were determined from ellipsometric data recorded over a wide spectral range (0.05–6 eV). Different parametrization of Ge25S75 complex dielectric permittivity which consists of a Tauc-Lorentz or Cody-Lorentz oscillator describing the short wavelength absorption edge, a Lorentz or Gauss oscillators describing phonon absorption or optically active absorption of alkyl ammonium germanium salts in the middle infrared part of spectra is discussed. Using a Mott-Davis model, the decrease in local disorder with increasing annealing temperature is quantified from the short wavelength absorption edge onset. Using the Wemple-DiDomenico single oscillator model for the transparent part of the optical constants spectra, a decrease in the centroid distance of the valence and conduction bands with increasing annealing temperature is shown and increase in intensity of the inter-band optical transition due to annealing temperature occurs. Intensity of absorption near 3000 cm−1 could be used as alternative method to evaluation of quality of prepared films.

The aim of this study was to evaluate neuroendocrine activation during stress in patients with recently diagnosed multiple sclerosis before starting the immunomodulatory therapy (EDSS score≤2.0). We verified the hypothesis that certain cognitive and affective dysfunction is present already at this early stage of the disease. The sample consisted of 38 subjects, which involved patients who were recently diagnosed multiple sclerosis and age- and sex-matched healthy volunteers. Stroop test served as mental stress model enabling measurement of cognitive performance. Present results showed increased state anxiety, depression scores and poorer performance in the Stroop test in the group of patients compared to healthy subjects. The cognitive dysfunction was particularly evident in male patients with simultaneously decreased concentrations of the brain-derived neurotrophic factor (BDNF) in plasma. The patients at this stage of the disease have not yet developed the hyperactivity of the hypothalamic-pituitary-adrenocortical axis. They showed normal levels of plasma copeptin and reduced aldosterone response to mental stress test in women only. Concentrations of plasma copeptin were higher in men compared to women. Very early stages of multiple sclerosis are accompanied by disturbances in psychological well-being, mild cognitive dysfunction and decreased plasma concentrations of BDNF, particularly in male patients.

Semiconductor quantum dots (QDs) are well known photoluminescent materials. Their potential practical applications depend on their physico-chemical and luminescent properties and also on the properties of hosting material. To ensure that QDs retain their photoluminescence during the preparation of a suitable solid composite form, the solution based casting techniques with deposition at lower temperatures are usually used. In our work, we have doped an inorganic Ge25S75 chalcogenide glass matrix with synthesized CdS0.9Se0.1 QDs and prepared thin films by the solution based spin-coating technique. In comparison with commonly used polymers the Ge25S75 chalcogenide glass thin films a possess high refractive index and wide VIS-NIR-MIR optical transparent region. We also report on the phenomenon of significant UV exposure induced increase of doped thin film photoluminescence intensity which can be exploited in local photo-induced photoluminescence enhancement of doped chalcogenide glass thin films.

Nanostructurization in three types of tetra-arsenic tetra-sulfide As4S4 polymorphs composed by (1) preferential β-As4S4, (2) realgar α-As4S4 and (3) admixture of As4S4 in the form of β-realgar, pararealgar and intermediate χ-phase subjected to mechanochemical ball milling in a water solution of polyvinylpyrrolidone (PVP) are characterized with multiexperimental structure-sensitive probes. Void structure of pelletized As4S4-PVP nanocomposites is probed by positron annihilation lifetime spectroscopy complemented with atomic-sensitive techniques such as X-ray powder diffraction, Raman scattering and scanning electron microscopy with energy-dispersive X-ray spectroscopy. Appearance of arsenolite As2O3 crystallites is character for all As4S4 polymorphs affected by wet milling. Positron annihilation lifetime data considered in terms of substitution positron-positronium trapping confirm complicated nature of nanocomposites. Modified x3-x2-coupling decomposition algorithm developed in addition to unconstrained x3-term fitting procedure is applied to parameterize annihilation channels in these nanocomposites. Interfacial free-volume voids between neighboring nanoparticles in PVP environment are defined as most favorable trapping sites, they being rather loosely composed by As4S4 crystallites in full respect to variety of crystallographic polymorphs used for milling. Detected annihilation channels are ascribed preferentially to intrinsic free-volume voids insensitive to trapping states at the surface of oxidized nanocomposites.

Arsenic sulphide β-As4S4 has been modified by mechanical activation in a planetary ball mill. As a consequence, the solid-state properties and dissolution yield have been influenced. The following changes were observed: the increase of specific surface area, changes in the morphology (the formation of submicron particles), the occurrence of nanoparticles (21–31 nm), changes in crystal lattice parameters and changes in the Raman shift of particular vibrations. As a consequence of these changes, the dissolution rate of β-As4S4 has been increased, which is a challenge for the application in cancer research.

Chalcogenide glasses are intensively studied materials due to their interesting optical properties such as high values of refractive index, wide transparency in IR, photosensitivity, etc. We report on the comparison of photo and thermo-induced changes in optical properties and chemical resistance of thermally evaporated and spin-coated As30S45Se25 thin films. Significantly different trends of photo-induced changes in chemical resistance in both types of thin films such as negative etching of thermally evaporated thin films and positive etching of spin-coated thin films were observed. The structural changes responsible for the observed phenomena were investigated as well.

Spectral dependence of photoinduced structural transformation and related changes of E g opt , α and n of thermally evaporated ternary As 40 S 60-x Se x thin films have been studied under the exposure to bandgap and super-/sub-bandgap light of LED. The irradiation by bandgap and super-bandgap light with intensity 0.1 W/cm 2 leads to partial photoinduced polymerization of molecular structural units into continuous network that is characteristic for the bulk glasses with appropriate stoichiometric composition. The efficiency of structural transformation depends on penetration depth of excitation beam. The maximum photosensitivity (i.e. changes of E g opt , α and n ) were achieved at the wavelengths ~ 100 nm above the bandgap wavelength for each appropriate composition. Beyond the region of maximal photosensitivity the values of optical parameters and kinetics of photoinduced changes depend on relation between exposed and unexposed sublayer for super-bandgap beams or on absorption coefficient for sub-bandgap light.

Hypoxia - a state of lower oxygen demand-is responsible for a higher aggressiveness of tumors and therefore a worse prognosis. During hypoxia, several metabolic pathways are re-organized, e.g., energetic metabolism, modulation of pH, and calcium transport. Calcium is an important second messenger that regulates variety of processes in the cell. Thus, aim of this work was to compare H2S modulation of the intracellular calcium transport systems in hypoxia and in cells grown in standard culture conditions. For all experiments, we used ovarian cancer cell line (A2780). H2S is a novel gasotransmitter, known to be involved in a modulation of several calcium transport systems, thus resulting in altered calcium signaling. Two models of hypoxia were used in our study-chemical (induced by dimethyloxallyl glycine) and 2 % O2 hypoxia, both combined with a treatment using a slow H2S donor GYY4137. In hypoxia, we observed rapid changes in cytosolic and reticular calcium levels compared to cells grown in standard culture conditions, and these changes were even more exagerrated when combined with the GYY4137. Changes in a calcium homeostasis result from IP3 receptor´s up-regulation and down-regulation of the SERCA 2, which leads to a development of the endoplasmic reticulum stress. Based on our results, we propose a higher vulnerability of calcium transport systems to H2S regulation under hypoxia.

Doping of semiconductor quantum dots (QDs) by transition metals (such as Mn, Cu, Ni, etc.) is a great technique to impact the optical and structural properties of the host materials. The introduction of a small amount of impurity into the host semiconductor matrix leads to the shift of PL emission due to the change in the recombination process. The new emission pathways created by dopant influence the photoluminescence intensity, Stokes shift, lifetime and stability of QDs. Mn-doped ZnS QDs (1–15 mol. %) have been synthesized by the effective low-cost and nontoxic hot-injection method. N-phenylmorpholine-4-carbothioamide has been successfully applied as a novel source of sulfur in the synthesis of Mn-doped ZnS QDs. X-ray diffraction (XRD), scanning transmission electron microscopy (STEM) and infrared (IR) spectroscopy were used for the characterization of morphology and structure of synthesized Mn-doped ZnS QDs. Our materials exhibit strong photoluminescence yellow-orange emission with a photoluminescence quantum yield (PL QY) of 41%. All Mn-doped ZnS QDs have a face-centered cubic structure with a mean crystalline size of 3.8–5.1 nm. Additionally, this synthetic approach enables the synthesis of Mn-doped ZnS QDs with tunable band gaps between ∼3.5 eV and 3.60 eV.

A novel approximating polynomial of an equiripple low-pass FIR filter is presented. It represents an optimal equiripple polynomial approximation of two constants in two disjoint intervals. It also provides an insight into the nature of the approximation problem. The developed equiripple approximation is illustrated in two examples.