Formation and Ripening of Nanobelts/Nanofibers under Stirring of aqueous Solution – alternative models

Problem of V2 O5 nanobelts production under intensive stirring of V2 O5 powder in salted water is revisited. Method was initially proposed in 2016 but models and understanding were lacking. Here an independent attempt of the controlled V2 O5 nanobelts formation and growth under stirring with various rotation frequencies is reported, as well as some alternative mechanisms and respective mathematical models of the nanobelts growth and ripening kinetics

Silver nanoparticle-based assay for the detection of immunoglobulin free light chains

There is a wide spectrum of malignant diseases that are connected with the clonal proliferation of plasma cells, which cause the production of complete immunoglobulins or their fragments (heavy or light immunoglobulin chains). These proteins may accumulate in tissues, leading to end organ damage. The quantitative determination of immunoglobulin free light chains (FLCs) is considered to be the gold standard in the detection and treatment of multiple myeloma (MM) and amyloid light-chain (AL) amyloidosis. In this study, a silver nanoparticle-based diagnostic tool for the quantitation of FLCs is presented. The optimal test conditions were achieved when a metal nanoparticle (MNP) was covered with 10 particles of an antibody and conjugated by 5-50 protein antigen particles (FLCs). The formation of the second antigen protein corona was accompanied by noticeable changes in the surface plasmon resonance spectra of the silver nanoparticles (AgNPs), which coincided with an increase of the hydrodynamic diameter and increase in the zeta potential, as demonstrated by dynamic light scattering (DLS). A decrease of repulsion forces and the formation of antigen–antibody bridges resulted in the agglutination of AgNPs, as demonstrated by transmission electron microscopy and the direct formation of AgNP aggregates. Antigen-conjugated AgNPs clusters were also found by direct observation using green laser light scattering. The parameters of the specific immunochemical aggregation process consistent with the sizes of AgNPs and the protein particles that coat them were confirmed by four physical methods, yielding complementary data concerning a clinically useful AgNPs aggregation test

Polymer-carbon composite for guided tissue regeneration

Leczenie chorób przyzębia techniką kontrolowanej regeneracji tkanek wymaga od implantu, aby pełnił rolę membrany odizolowującej komórki tkanki łącznej i nabłonka dziąsła od miejsca gojenia i umożliwiał komórkom ozębnej repopulację i utworzenie cementu korzeniowego z wbudowanymi włóknami kolagenowymi. W stomatologii obserwuje się coraz większe zainteresowanie implantami membranowymi do leczenia chorób przyzębia. Znanych jest wiele materiałów organicznych resorbowalnych i nieresorbowalnych, z których wytwarza się implanty dla sterowanej rekonstrukcji tkanek. W pracy przedstawiono próbę otrzymania trójfazowego implantu będącego połączeniem dwóch biozgodnych składników a mianowicie: włókniny węglowej i poli-L-laktydu. Zewnętrzną część implantu stanowi błona polimerowa będąca barierą dla niepożądanych komórek nabłonka zaś wewnętrzna część zbudowana jest z włókien węglowych stymulujących proces regeneracji tkanki kostnej. Implant polimerowo- węglowy został poddany badaniom przy zastosowaniu metod: FTIR, SEM i DSC co pozwoliło na charakterystykę jego budowy chemicznej i morfologii, natomiast inkubacja próbek w sztucznym płynie ustrojowym dostarczyła danych o trwałości implantu w warunkach in vitro.In the treatment of parodontopathy by guided tissue regeneration, it is required that the implant should play a role of a membrane that separates the connective tissue and gingival epithelium from the healing site. It should also permit repopulation of the periodontium cells along with formation of tooth root cement with the collagen fibres. In stomatology the interest in membrane implants for the treatment of parodontopathy continually increases. There are many resorbable and non-resorbable organic materials used as implants in guided tissue reconstruction. This work is an attempt to develop a three-phase implant being a combination of two biocompatible components, i.e. carbon felt and poly-L-lactide. The outer part of the implant is built of a polymeric membrane, a barrier for undesirable gingival epithelium cells, while the inner part consists of carbon fibres that stimulate the process of bone tissue regeneration. The polymer-carbon implant was examined using FTIR, SEM, and DSC, to characterise its chemistry and morphology, while incubation of samples in simulated body fluid provided the data on their stability in the in vitro conditions

Multifunctional carbon aerogels derived by sol–gel process of natural polysaccharides of different botanical origin

In this manuscript, we describe the results of our recent studies on carbon aerogels derived from natural starches. A facile method for the fabrication of carbon aerogels is presented. Moreover, the complete analysis of the carbonization process of different starch aerogels (potato, maize, and rice) was performed using thermogravimetric studies combined with a detailed analysis of evolved decomposition products. The prepared carbon aerogels were studied in terms of their morphology and electrical properties to relate the origin of starch precursor with final properties of carbon materials. The obtained results confirmed the differences in carbon aerogels’ morphology, especially in materials’ specific surface areas, depending on the botanical origin of precursors. The electrical conductivity measurements suggest that carbon aerogels with the best electrical properties can be obtained from potato starch

Electrochemically deposited nanocrystalline InSb thin films and their electrical properties

We present an electrochemical route to prepare nanocrystalline InSb thin films that can be transferred to an industrial scale. The morphology, composition, and crystallinity of the prepared uniform and compact thin films with a surface area of around 1 cm2 were investigated. The essential electrical characteristics such as conductivity, Seebeck coefficient, the type, concentration and mobility of charge carriers have been examined and compared with InSb nanowires obtained in the same system for electrochemical deposition (fixed pulse sequence, temperature, electrolyte composition, and system geometry). Moreover, obtained thin films show much higher band gap energy (0.53 eV) compared to the bulk material (0.17 eV) and InSb nanowires (0.195 eV)

Influence of polyvinylpyrrolidone (PVP) in the synthesis of luminescent NaYF4:Yb,Er upconversion nanoparticles

Polyvinylpyrrolidone (PVP) can be used to produce upconversion nanoparticles (UCNPs) in an advantageous manner, i.e. at modest temperatures in open-to-air conditions with simple hotplate and flask apparatus. However, the influence of PVP parameters on the formation of UCNPs has not been previously investigated. In this exploratory study, we establish that PVP molecular weight and relative amount of PVP can greatly influence the morphology and diameter of NaYF4:Yb,Er UCNPs produced via the PVP-assisted route. At nominal amounts of PVP, varying the molecular weight of PVP in synthesis between 10,000 g/mol (PVP10), 40,000 g/mol (PVP40), and 55,000 g/mol (PVP55), had minimal effect on UCNP morphology, whereas reducing the quantity of PVP10 and PVP40 in the reaction to 10% of the nominal amount resulted in two notable effects: (1) the generation of a greater range of UCNP diameters and (2) the production of an unexpected sub-population of rhombus-shaped UCNPs. Bulk and individual nanoparticle analysis indicates that all UCNP morphologies were cubic (α-phase) crystal structure and consisted of NaYF4:Yb,Er. Optical emission properties exhibited only modest green and red luminescence emission ratio when PVP parameters were varied. However, separately produced PVP40 NaYF4:Yb,Tm UCNPs exhibited a much more intense and dual-band blue /red emission. This exploratory work demonstrates that tailoring PVP content in synthesis of UCNPs can greatly alter morphology of UCNPs produced and should be carefully considered in experimental design. However, the underlying mechanisms of action of the role PVP plays in this synthesis remain unclear. Ultimately, significant further work is still required to fully elucidate the relevant chemistry to achieve full control of PVP-UCNP synthesis

What is a bigger problem in teenagers overweight or underweight?

WSTĘP. Nadwaga i otyłość jest jednym z istotnych problemów zdrowotnych w każdej grupie wiekowej. Według wielu autorów niniejszej pracy, to jedno z najczęściej występujących zaburzeń rozwojowych u dzieci i młodzieży. Cele opracowania to ocena częstości występowania nadwagi i otyłości w grupie osiemnastolatków oraz określenie czynników ryzyka nadwagi i otyłości w badanej grupie. MATERIAŁ I METODY. Badaniami metodą sondażu diagnostycznego objęto 201 osiemnastolatków — uczniów klas trzecich liceum ogólnokształcącego. Podczas badań wykorzystano kwestionariusz ankiety oraz wykonano pomiary obwodów talii i bioder. WYNIKI. Na podstawie wskaźnika BMI nadwagę stwierdzono u 10,9% osób, otyłość u 2,0%. U około 13% badanych dziewcząt stwierdzono niedowagę. Istotnie częściej nadwaga i otyłość występowały u chłopców niż u dziewcząt (8,1% v. 15,4%, p = 0,034). Czynnikami ryzyka występowania nadwagi i otyłości u badanych nastolatków były uwarunkowania rodzinne (42,3%), niska aktywność fizyczna (39,8%) oraz błędy żywieniowe. U ponad połowy osiemnastolatków stwierdzono nieregularność odżywania, 75% badanych jadało słodycze między głównymi posiłkami, 86,6% młodzieży późno spożywało ostatni posiłek, 17,9% badanych sięgało po posiłki typu fast-food. W badanej populacji co piąty uczeń nie uczęszczał na lekcje wychowania fizycznego, 34,8% uczniów nie uprawiało żadnych sportów, 58,7% młodzieży spędzało swój wolny czas przed komputerem, a 24,9% — oglądając telewizję. WNIOSKI. Znaczny odsetek młodzieży szkolnej cierpi na nadwagę i otyłość. Z drugiej strony istotna grupa dziewcząt ma niedowagę. Duża część młodzieży popełnia błędy żywieniowe i nie uprawia żadnych sportów. Wolny czas młodzi ludzie spędzają w sposób bierny. Należy zwrócić większą uwagę na edukację dzieci i młodzieży oraz motywowanie ich do przestrzegania zasad zdrowego stylu życia.INTRODUCTION. Overweight and obesity belong to the most important health problems at every age. According to many authors they are the most frequent growth disturbances in youngsters. The aim of the study was to assess frequency of overweight and obesity in the group of eighteens and evaluation of the risk factors of overweight and obesity. MATERIAL AND METHODS. We enrolled 201 eighteens — pupils of high school who answered the questions from the survey on a diet and physical activity. Measurements of weight, waist and hips were taken in the whole group. RESULTS. According to BMI there were 10,9% overweight persons and 2,0% obese young people. In 12,2% of the girls we observed underweight. Significantly more boys were overweight and obese than the girls (8,1% v. 15,4%, p = 0,034). Following risk factors of overweight and obesity were found: family circumstances (42,3%), low physical activity (39,8%) and inappropriate diet. About 50% of eighteens ate irregularly, 75% ate sweets between the main meals, 86,6% had their last meal late at night, 17,9% ate „fast-foods”. In our population very fifth pupil did not attend physical education, 34,8% of the pupils did not practice any sports, 58,7% of the eighteens spent their leisure time using computer and 24,9% watching television. CONCLUSIONS. Significant percentage of teenagers are overweight or obese. On the other hand big group of the girls are malnourished. Substantial group of eighteens are on inappropriate diet and do not practice any sport. Young people spent their leisure time passively using computer and watching television. More attention should be focused on education of school children and youth on healthy life style