Izhodišče: Zadosten vnos hranil je v otroštvu izrednega pomena. V nekaterih primerih hranjenje in pitje preko ust ni mogoče oziroma ne zadosti potrebam po hranilih pri otroku. Če napoved izida ...bolezni ni ugodna in bo otrok predvidoma več kot štiri tedne odvisen od enteralnega hranjenja, je smiselna vstavitev perkutane endoskopske gastrostome (PEG), ki omogoča stalen enteralni dostop. Metode: Raziskava je bila retrospektivna. Pregledali smo zdravstveno dokumentacijo otrok, ki smo jim vstavili PEG v obdobju od maja 2011 do maja 2019. Rezultati: V raziskavo je bilo vključenih 124 otrok, od tega 64 (51,6 %) fantov. Srednja starost ob vstavitvi PEG je bila 42 mesecev. Večina otrok (91,9 %) je pred vstavitvijo PEG prejela odmerek antibiotika. Veliko večino otrok (96 %) smo po PEG začeli hraniti 24 ur po vstavitvi PEG. 57,3 % otrok, ki smo jim vstavili PEG, je imelo nevrološko bolezen. V povprečju smo primarno gastrostomo zamenjali z nizkoprofilno gastrostomo po petih mesecih. V enem letu po vstavitvi PEG so otroci pridobili telesno maso (v povprečju 3 kg). Od 124 otrok, ki so bili vključeni v raziskavo, je 96 (77,4 %) otrok razvilo enega ali več zapletov, povezanih s PEG. Večina zapletov je bila lažjih oziroma prehodnih. Zaključek: Glede na podatke otrok, ki smo jim v zadnjih 8 letih vstavili PEG na otroški kliniki, lahko zaključimo, da je vstavitev hranilne cevke na endoskopski način varna in učinkovita metoda za zagotavljanje dolgotrajne enteralne prehrane pri kronično bolnih otrocih.
The formation of giant hailstones is a rare weather event that has devastating consequences in inhabited areas. This hazard has been occurring more frequently and with greater size of hailstones in ...recent years, and thus needs to be better understood. While the generally accepted mechanism is thought to be a process similar to the formation of smaller hailstones but with exceptional duration and stronger updrafts, recent evidence suggests that biotic and abiotic factors also influence the growth of these unusually large ice chunks. In this study, we improved these findings by determining the distribution of a wide variety of these factors throughout the hail volume and expanding the search to include new particles that are common in the environment and are of anthropogenic origin. We melted the concentric layers of several giant hailstones that fell to the ground over a small region in Slovenia in 2019. The samples, up to 13 cm in diameter, were analyzed for biotic and abiotic constituents that could have influenced their formation. Using 16S rRNA-based metagenomics approaches, we identified a highly diverse bacterial community, and by using scanning electron microscopy and Raman spectroscopy, we found natural and synthetic fibers concentrated in the cores of the giant hailstones. For the first time, we were able to detect the existence of microplastic fibers in giant hailstones and determine the changes in the distribution of sand within the volume of the samples. Our results suggest that changes in the composition of hail layers and their great diversity are important factors that should be considered in research. It also appears that anthropogenic microfiber pollutants were a significant factor in the formation of the giant hailstones analyzed in this study.
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•The first evidence of fibrous microplastics has been found in a hailstone.•Giant hailstones are rich in abiotic and biotic structures.•A highly diverse bacterial community structure was identified in hailstones.•Fibrous particles may affect the formation of hailstones.
In the late XX and early XXI century, the uncontrollable and irreversible worldwide spread of macro- (>5 mm), micro- (5 µm–5 mm), and nanoplastic (<5 µm) pollutants have represented a growing ...concern. Recent ‘food for thought’ research provided by Isobe
et al
. offers a pessimistic forecast, suggesting the amount of non-conservative microplastics will increase twofold and fourfold by 2030 and 2060, respectively.1 Freshly published reports point to the fact that human-made polymer debris can be detected virtually anywhere on the globe.2, 3 The capabilities of today’s analytic optical instrumentation, such as Fourier-transform infrared spectroscopy and linear Raman spectroscopy far exceed requirements for chemical characterization of polymer pollutants. Recently it was shown that nanoplasmonic materials could be used to advance the vibrational spectroscopy considerably.
A combination of nanostructured metallic surfaces and Raman scattering represents a powerful analytic tool, known as surface-enhanced Raman spectroscopy (SERS). In the current report, we demonstrate that carbon-based nanostructures are an excellent accessory for microplastic recognition in Raman spectroscopy. The primary reason for this great success is attributed to extraordinary electronic properties, which facilitate ultrafast charge transfer reactions and
π
-plasmon resonance. A second reason is related to specific their chemical features from the affinity of carbon atoms to hybridization in sp, sp
2
, and sp
3
electronic states allowing to form different morphologies such as of vertical nanowalls, aligned nanotubes, and nanocones. On the base of the last one, we showed that electromagnetic enhancement mechanism, which is more pronounced at the vicinity of sharp tips and thin edges, improves the intensity of peaks within a vibrational spectrum of plastic micro-fragments.
Prepared with the assistance of low-pressure radio-frequency (RF) inductively coupled plasma-enhanced chemical vapour deposition (PE-CVD) system and using Ni-film as a supporting-catalytic material the
vertically aligned carbon nanocones
(VACNs) revealed the high stability and prominent surface roughness at the nanoscale. By Raman and XPS analysis was suggested the designed sample possesses high
I
D’
/
I
G
ratio, which is mainly attributed to the presence of structural defects and microcrystalline graphitic edges that is accompanied by a dominant contribution of sp
2
carbon surface component. After deposition of gold, the dark-field microscopy confirmed a high plasmonic activity in a visible spectral range favouring the use of greenish excitation wavelength. Employing SERS measurement and taking a Rhodamine 6G as a marker compound was established, the enhancement factor achieves a value of about 10
7
stating the excellent analytical performance.
Fully characterized substrate was used to enhance Raman scattering cross-section of the polypropylene (PP), polyethylene terephthalate (PET), polyurethane (PU), and polyamide (PA) microparticles. First, to prove the SERS effect, we compared the vibrational spectra of the tiniest plastic species collected from the plasmonic conical nanostructure (VACNs) and the glass slice. The selected PP fragments were ∼10 µm big (Figure 1 f). Surprisingly, by reducing exposure time down to 0.25 s the PP signal from the nanoconical texture was still readable. It was observed that Raman scattering intensity of PP from a plasmonic substrate is approximately an order of magnitude higher than from glass for the shortest illumination time.
To identify a polymer type, we designed a simple strategy. At first, we collected Raman vibrational spectra from all the samples and removed the accompanying background noise by applying a locally estimated scatterplot smoothing (LOESS) filter. Then, signal intensities were normalized to 100. The method was applied for all high-quality SERS spectra from each microplastic fragment. Acquired graphs were analyzed with the orthogonal partial least squares discriminant analysis algorithm.
In the plot displayed in Figure 1 g, five nicely separated data clusters are seen. Two data groups colored ‘blue’ and ‘violet’ that correspond to PU and PA reveal the most similar features of Raman spectra; however, they are still far apart Based on eigenvalues, the average identification accuracy of the proposed PCA method reaches a value above 97.5%. Among the total 97 microplastic fragments tested, the precise quantity of PP is 27, PA is 36, PU is 15, and PET fibers is 11. The other eight species did not cluster close to any other polymer, suggesting their different origin of appearance on the experimental table.
Figure 1.
A summary of the research. (a–e) A set of optical images showing the general look of tested polymer micro-fragments. (f) - High-resolution spectra of PP particle with an approximate size of ~10 microns (see inserted digital images) on the conical SERS nanostructure taken at different exposure times. (g) - Results of PCA displayed via a loading graph plotted as PC2 vs PC3, revealing clustered spectra that are related to the type of polymer. (h-i) - SEM images showing surface features of the
vertically aligned carbon nanocones
before and after sputtering of 100 nm-thick gold film.
Acknowledgements
This work was supported by the Slovenian Research Agency ARRS grants NI-0001, and N2-0091.. The work was partially performed under the framework of the PEGASUS project, funded by the European Union's Horizon research and innovation program under grant agreement No. 766894. NMS acknowledges the support of AD FUTURA, Public Scholarship, Development, Disability, and Maintenance Fund of the Republic of Slovenia.
References
1 A. Isobe, S. Iwasaki, K. Uchida, T. Tokai,
Nat. Commun.
2019
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10
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2 B. Boots, C. W. Russell, D. S. Green,
Environ. Sci. Technol.
2019
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53
, 11496.
3 S. Ziajahromi, P. A. Neale, L. Rintoul, F. D. L. Leusch,
Water Res.
2017
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112
, 93.
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