Unusual way to the diagnosis of neuroblastoma

Neuroblastom, nádor sympatického nervového systému, je nejčastějším extrakraniálním solidním nádorem dětského věku. Představuje 15 % ze všech nádorů diagnostikovaných u dětí mladších pěti let. Klinické příznaky neuroblastomu závisí od umístění primárního nádoru nebo místa metastatického onemocnění. V dutině břišní se vyskytuje až 65 % primárních neuroblastomů. Prezentujeme 5letého chlapce s bolestmi břicha po pádu ze schodů, u kterého ultrazvukové vyšetření vedlo k diagnóze rozsáhlého neuroblastomu pravé nadledviny. Klíčová slova: neuroblastom, nadledvina, ultrazvuk, úraz dutiny břišní, předškolní dítě.

A giant bladder cystine stone in a 5-year‑old female patient

The effect of humic acids adsorption on pH-dependent surface charging and aggregation of Fe3O4-APTES nanoparticles

Humic acids (HA) are often used as a stabilizer for magnetite nanoparticles (Fe3O4) and as a functional component for magnetic nanocomposites. Despite the protective shell of HA the oxidative degradation of Fe3O4 to maghemite Fe2O3 nanoparticles is observed. This led to a change in the biological activity of the composite (Terekhova et al., 2018). To improve chemical stability of Fe3O4 the surface charge control was used through pretreatment using silanes. In this study, effect of HA adsorption on pH-dependent surface charging and aggregation of the Fe3O4 functionalized by 3-aminopropyl-triethoxysilane (APTES) was studied. A set of the Fe3O4-APTES samples were formulated: under argon (Ar) or air atmosphere and/or further dialysis (D) and subsequent treatment of the samples: in harsh (US-treatment) and mild (magnetic stirrer, M) conditions. As a total, five samples were obtained: Fe3O4, Fe3O4-APTES (Ar), Fe3O4-APTES (Ar-D-M), Fe3O4APTES (Ar-D-US), and Fe3O4-APTES (air). Magnitude of isoelectric points (iep, the pH of ξ = 0), zeta-potential and hydrodynamic size were measured at 25 ± 0.1 °C in a disposable zeta cell (DTS 1060) of NanoZS (Malvern, UK) apparatus [2]. The range of pH was between ∼3 and ∼10. According to the magnitude of the shift of the pH-dependent zeta potential functions due to the sorption of increasing amount of HA in case of all samples, it is possible to formulate a series of samples in which the sorption capacity decreases: Fe3O4-APTES (Ar-D-M)≥ Fe3O4-APTES(air) > Fe3O4≥Fe3O4-APTES(Ar-D-US) >> Fe3O4-APTES (Ar). Treatment way has a great effect on the sorption capacity of the samples. Dialysis of the sample Fe3O4-APTES (Ar) led to enhance adsorbing of HA. The sample exposed to the magnetic stirrer has a larger sorption capacity than the sample after the US-treatment: Fe3O4-APTES (Ar-D-M)> Fe3O4-APTES (Ar-D-US) >> Fe3O4-APTES (Ar). It is likely that harsh conditions during sonication (extreme high temperature and pressure in cavities forming at interfaces) led to destroy Fe3O4-APTES-HA bonds and reduce the sorption capacity. The hydrodynamic diameter increases near the isoelectric point for the samples Fe3O4-APTES without HA. The hydrodynamic size for the samples Fe3O4-APTES at pH 9 varied from 700 nm to 300 nm. In the range 5<pH<9, the hydrodynamic size is about 100-300 nm. But, the hydrodynamic diameter for Fe3O4-APTES the increases near the isoelectric point (from 200 to 750 nm), when not fully coverage with HA. In case of full coverage with HA, the hydrodynamic size remains unchanged at all pH range (around 150 nm for all of samples).

Humic acids impact on bioactivity and aging of iron ions or nanoparticles

Stabilizing ability of humic acids towards Fe3O4 nanoparticles under various oxidation conditions

Humic acids (HA), natural polyelectrolytes and strong chelates can effectively prevent the aggregation of magnetite nanoparticles, from one side, and from another side, HA as antioxidants can affect the iron species state. The increasing application of iron-based nanoparticles has raised concerns regarding their environmental behavior and potential ecological effects. After release into the environment, iron-based NPs undergo various transformations via the interactions with different geochemical and biological components, which ultimately influence their behavior and potential toxicity. In this study, the oxidation of HA-coated magnetite nanoparticles (Fe3O4-HA NPs) is investigated under mild and harsh conditions in order to understand the oxidation behavior and the chemical stability of transition forms in the presence of humic acids. XRD analysis and Mössbauer spectroscopy were used to identify the phase composition of NPs and the change in the oxygen environment of iron atoms. The chemical precipitation in situ method with in the HA matrix or the self-assembly method was used to formulate the Fe3O4 NPs from Fe(II) and Fe(III) salts by NH4OH addition in argon atmosphere. To simulate the oxidation process of the Fe3O4-HA three treatment ways were used: mild (storage in tap water during 24 hours, st) and two huge conditions (influence of concentrated HNO3 or mechanical treatment in the grinder at 1400 rpm in 10 min in air atmosphere, mill). As a total, the following samples were analyzed: Fe3O4-HA (ini), Fe3O4-HA (st), Fe3O4-HA (HNO3) and Fe3O4-HA (mill) and NPs of Fe3O4 (ini), Fe3O4 (HNO3) as a control. According to the XRD data, main phase for all samples tested before and after oxidation is a magnetite Fe3O4 NPs. Complete phase transformation to maghemite Fe2O3 for all samples under treatment (storage in H2O, nitric acid and mechanical treatment) was evidenced by Mössbauer spectroscopic measurements. Thus, XRD technique suffers from serious limitations and ineffective in discriminating magnetite. The oxidative degradation of Fe3O4 to Fe2O3 nanoparticles changed in the order: Fe3O4 (HNO3) < Fe3O4-HA (st) < Fe3O4-HA (HNO3) < Fe3O4-HA (mill), and indicates oxidative effect of HA towards Fe ions. Mitigating effect of HA on bioactivity of two types of iron oxide nanoparticles of Fe3O4 and γ-Fe2O3 to the green algae Scenedesmus quadricauda and the higher plant (seeds of white mustard Sinapis alba) a higher plant (white mustard) were investigated with a focus on the effect of oxidation state. Results show that the growth inhibition by iron oxides nanoparticles (NPs) to both test-species increased with oxidation of the NPs with an order Fe3O4 (ini) < Fe3O4-HA (ini) < Fe2O3-HA (above Fe3O4-HA (mill)). The main toxic mechanism, which could explain the difference in toxicity of the NPs is probably Fe and Fe ions release. These findings will be helpful for the understanding of HA role on the fate and toxicity of iron-based NPs in the environment.

Separation of oil-water mixtures using humic acids-coated magnetic nanoparticles

Adsorption of ciprofloxacin and diclofenac using humics and silica-coated Fe3O4 nanoparticles

The emerging pollutants such as non-steroidal anti-inflammatory drugs (diclofenac sodium, DCF) and antibiotics (ciprofloxacin, CIP) have aroused increasing concerns, and the efficient removal of pharmaceuticals from wastewater is becoming an urgent problem. An eco-friendly composites consisting of Fe3O4 nanoparticles modified by humic acids (HA) and/or 3-aminopropyl-triethoxysilane (APTES) have been fabricated via an in-situ/solgel method, characterized and used for CIP and DCF adsorptive removal. XRD, SEM, Mossbauer spectroscopy, zeta potential (DLS), N2 adsorption-desorption measurements and elemental analysis were employed to characterize all synthesized composites: Fe3O4/APTES, Fe3O4/HA, Fe3O4/APTES/HA. The adsorption kinetics, isotherms as well as various influence factors, e.g., pH, ionic speciation and strength on the CIP and DCF removal were systematically investigated. The CIP and DCF recovery was studied from 0.1 mM solutions at solid:liquid ratio 1:1000, pH 7.5, and the contact time 24 h. The equilibrium concentrations were determined spectrophotometrically. Fe3O4 conjugation with humic acids lead to increase specific surface from 117 to 142 m/g for the Fe3O4 and the Fe3O4-HA20 (20 wt% of HA), respectively. The sorbents under study are characterized by a high sorption capacity regarding to ciprofloxacin. The results obtained indicate that the adsorption of CIP by the Fe3O4-HA20 is largely enhanced in comparison with the bare Fe3O4. High uptakes of diclofenac reaching 178 and 256 mg g for Fe3O4/APTES/HA and Fe3O4/APTES composites respectively proved that the obtained xerogels are potential candidates for removal of drugs from waters and wastewaters. The isotherm of DCF adsorption was described well by the Freundlich model. The results showed that the presence of HA weakened the sorption capacity of Fe3O4/APTES, but decreased its toxicity towards Paramecium caudatum and Sinapis alba. To maximize the removal degree for DCF, ultrasonic (US) treatment in the absence or presence of Fe3O4/APTES and HA was investigated. Two frequencies, three time and three pH conditions were tested (30 and 100 kHz; 5, 10, and 30 min and 3, 7, and 9, respectively). The adsorption of DCF has increased when Fe3O4/APTES in the presence HA was sonicated at 100 kHz, pH 3 (58%, respectively) compared with 30 kHz, pH 3 (32%, respectively) within 30 min. These facts suggested that the fabricated composites have great potential for CIP and DCF-contaminated water treatment.

Formulation of multilayer magnetic Cu2+ and Ni2+ – imprinted sorbents based on humic acids

Synthesis of hydroxide iron(III), which stabilized by fulvic acid. Comparison and characteristic iron binding capacity

O GÊNIO DIDEROTIANO E A POÉTICA DAS MONTANHAS

O presente artigo tem como objetivo caracterizar o conceito de genio conforme os textos de juventude de Denis Diderot. Procedendo com a analise de obras dos anos 1740 e 1750, sobretudo os "Dialogos sobre o Filho natural" (1757), veremos como a ideia de genio e representada pela uniao de caracteristicas que, a primeira vista, podem parecer inconciliaveis.