Cilj je ovoga preglednog rada ukazati na moguće rizike prijevremenoga poroda za daljnji razvoj djece te prikazati rezultate recentnih istraživanja psihofizičkoga zdravlja roditelja prijevremeno ...rođene djece. Istraživanja pokazuju da posljedice koje prijevremeno rođenje ima za djecu mogu biti ozbiljne, pri čemu rizik od neurorazvojnih poremećaja raste s nižom gestacijskom dobi djeteta i nižom porodnom težinom. Rizici prijevremenoga rođenja djeteta za roditelje mogu se očitovati neposredno i/ili dugoročno, od akutne stresne reakcije do poslijetraumatskoga stresnog sindroma, poteškoća u razvoju privrženosti, perzistirajuće intenzivne brige i straha za dijete, što je dodatno naglašeno prelaskom djeteta iz bolničkoga okruženja na kućnu njegu. Inicijalna emocionalna i informativna podrška medicinskoga osoblja, prakticiranje tzv. klokanske njege, dostupnost stručnjaka za mentalno zdravlje te neformalni izvori podrške izuzetno su važni čimbenici prilagodbe roditelja. Pregled suvremenih istraživanja upućuje na potrebu za daljnjim ispitivanjima čimbenika koji se dovode u vezu s (ne)uspješnom psihofizičkom prilagodbom roditelja na prijevremeno rođenje djeteta i skrb o nedonoščetu. Budući da je adekvatno suočavanje roditelja važan preduvjet razvojnih ishoda kod neurorizične djece, bitno je osigurati programe podrške roditeljima da bi se osnažila njihova znanja i kompetencije.
The aim of this review is to highlight possible risks preterm birth can have for the development of children and to present the results of recent research on psychophysical health of parents of prematurely born children. Research shows that, for children, the consequences of preterm birth can be serious, with the risk of neurodevelopmental disorders increasing with lower gestational age of the child as well as birth weight. For parents, the effects of child’s preterm birth can manifest immediately and/or long-term, and range from an acute stress reaction, to post-traumatic stress syndrome, difficulties in the development of attachment, persistent intense worry and fear for the child, which is further emphasized by the child’s transition from a hospital environment to home care. Initial emotional and informative support of the medical staff, practicing kangaroo care, as well as the availability of mental health experts and informal support sources are extremely important for parents’ adaptation. A review of contemporary research points to the need for further investigation of factors associated with the (un)successful psychophysical adaptation of parents to the premature birth of a child and the care of a premature infant. Since adequate parental coping is an important prerequisite for developmental outcomes in neuro-risk children, it is important to provide support programs for parents in order to strengthen their knowledge and competences.
Small‐angle X‐ray scattering (SAXS) is an accurate nondestructive method that requires a minimum of sample preparation and is employed to study porosity, morphology and hierarchical structures. ...Zeolites and silica are among the porous materials that are widely investigated by SAXS. However, studies of covalent organic frameworks (COFs) are still scarce. In the present study, SAXS was employed to investigate meso‐ and microporous COFs, affording insightful information about their nanostructure textural properties. SAXS is especially useful when combined with other characterization techniques, such as powder X‐ray diffraction and N2 adsorption isotherms, emerging as an efficient tool to further characterize COFs. For microporous COFs, SAXS was used mainly to obtain quantitative values of surface roughness as a function of fractal parameters, in all cases indicating surface fractals of the large‐scale scattering object, namely the `grain'. Mesoporous COF studies allowed elucidation of their hexagonal structure on the basis of their structure peaks; however, the main result lies in the distinction between the pore and the grain, which are described as a hierarchical structure by the Beaucage model and evaluated according to their fractality. These COFs generally exhibit pores with mass fractal features and grains with surface fractal features when they are submitted to post‐functionalization, which may be due to the poor diffusivity of the functionalizing agents into the pores. In addition, a proposed aggregation description of the porous scattering objects was envisioned, based on small‐angle scattering premises, which was confirmed for a microporous COF by high‐resolution transmission electron microscopy.
Small‐angle X‐ray scattering models are applied to covalent organic frameworks in order to analyse fractal parameters and structure–scattering relationships.
Epidemiološke razmere v Sloveniji so vplivale tudi na izobraževalni proces, saj je bilo treba del izobraževalnega in svetovalnega procesa prenesti iz predavalnice in simulacijskega kabineta v spletno ...– virtualno okolje. V študijskem letu 2020/2021 je bil tako na Oddelku za babištvo izveden pilotni projekt z naslovom Virtualna priprava na porod in starševstvo. Gre za prvi poskus načrtovanja, oblikovanja, izvedbe in evalvacije virtualnega izobraževalnega programa na področju babištva, ki so ga izvedli študenti pod mentorstvom s prisotnostjo udeležencev – bodočih staršev. Poseben izziv je bilo dejstvo, da so bili študenti babištva postavljeni v dve vlogi, in sicer v vlogo študenta in vlogo zdravstvenega strokovnjaka, ki prvič samostojno (pod mentorstvom) izvaja virtualni izobraževalni program za bodoče starše za pridobitev lastnih strokovnih kompetenc. Velik poudarek je bil namenjen evalvaciji projekta in izvedbe nastopa na način kvalitativnega raziskovanja z uporabo fokusnih skupin. Rezultati kažejo, da se študenti zavedajo pomena in zahtevnosti oblikovanja virtualnega učnega okolja. Želijo si več časa za pripravo izobraževalnega progama, več usmeritev in več možnosti za izvedbo generalke pred nastopom. Posebej izpostavljeno je bilo stresno svetovalno delo pri odgovarjanju na vprašanja bodočih staršev, ki je potekalo po končani izvedbi v živo on-line.
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•Use of ultra small angle X-ray scattering technique to study pasteurized dairy products.•Simultaneous X-ray scattering data collection of fat globules and casein micelles.•Fat ...globule surface morphology became smoother as the fat content increased.•Observation of approximately 1 dimensional structures in pasteurized skim milk.•Structural changes observed around q = 8 × 10−3 Å−1 as the temperature increased from 7 °C to 45 °C.•Use of structure functions obtained from computer simulations of milks to explain the X-ray data.
Cows’ milk is a commodity used worldwide to make many dairy products. We have used the ultra small angle X-ray scattering (USAXS) technique to reveal the fat globule and casein micelle structures of some dairy products. USAXS covers the q-range 5 × 10−4 Å−1 < q < 10−1 Å−1, thereby allowing the study of micron-scale structures present in those dairy products. We measured the USAXS intensity, Iq, as a function of the scattering vector magnitude, q, for samples of skim milk, non-homogenized whole milk, homogenized whole milk, half and half and heavy cream, at two temperatures, 7 °C and 45 °C. The data collected from the scattering experiments were fitted using the Unified fit model run under the IRENA software from the Advanced Photon Source, Argonne National Laboratory (Illinois, USA). The fittings were carried out when the data were plotted as logI(q) vs logq. We observed a combination of linear regions (LRs) and knees. Two parameters of interest were obtained from the fittings, a radius of gyration, Rg, and a Porod exponent, P. Unified fit allowed us to fit up to four structural levels. One of the knees was centered at q ≈ 8 × 10−3 Å−1 for all samples measured at 7 °C, but vanished at 45 °C. Two LRs were identified as being either due to casein micelles (CMs) or to fat globules (FGs). The porod exponent obtained from these LRs allowed us to describe the surface morphology of CMs and FGs. Two of the Rg values gave a rough estimate of the FGs and CMs sizes. FGs were identified for samples of homogenized whole milk, half and half and heavy cream in the q-region 2 × 10−4 < q < 8 × 10−4 Å-1. We found that, in the absence of chymosin, or changes in pH, CaCl2 concentration or temperature changes, skim milk and non-homogenized whole milk displayed a Porod exponent that indicated a behavior characteristic of aggregation. Using computer simulations, we found that, seemingly, bovine CMs spontaneously formed approximately 1-dimensional aggregates possibly analogous to swollen randomly branched polymers.
Post-mechanical plating heat treatment induces the formation of an iron–zinc (Fe-Zn) rich intermetallic layer between Zn and ZnSn coatings and the substrate. Despite increased outer coating porosity, ...the corrosion resistance of Zn- and ZnSn-coated steels significantly improves after heat treatment, attributed to the formation of intermetallic phases. This study employs small- and ultra-small-angle neutron scattering (SANS and USANS) to investigate the behavior of mechanically plated Zn and ZnSn coatings pre- and post-heat treatment. In the presence of a relatively thick steel substrate, strong multiple scattering occurs. However, by identifying a specific high
Q
-range region where multiple scattering is negligible, we reveal small but significant differences. Porod’s slopes, denoted as ‘
n
’, are calculated for uncoated steel, and Zn- and ZnSn-coated steels (both with and without heat treatment). These slope values reflect contributions from different interfaces on the particles’ surface roughness. Despite the challenges of multiple scattering, our findings offer valuable insights into coatings’ behavior. The study lays a foundation for future investigations into coating behavior using SANS/USANS techniques.
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Inflammation processes are associated with significant decreases in tissue or lysosomal pH from 7.4 to 4, a fact that argues for the application of pH-responsive drug delivery ...systems. However, for their design and optimization a full understanding of the release mechanism is crucial.
In this study we investigated the pH-depending drug release mechanism and the influence of silk fibroin (SF) concentration and SF degradation degree of human serum albumin (HSA)-SF nanocapsules. Sonochemically produced nanocapsules were investigated regarding particle size, colloidal stability, protein encapsulation, thermal stability and drug loading properties. Particles of the monodisperse phase showed average hydrodynamic radii between 438 and 888 nm as measured by DLS and AFM and a zeta potential of −11.12 ± 3.27 mV. Together with DSC results this indicated the successful production of stable nanocapsules. ATR-FTIR analysis demonstrated that SF had a positive effect on particle formation and stability due to induced beta-sheet formation and enhanced crosslinking.
The pH-responsive release was found to depend on the SF concentration. In in-vitro release studies, HSA-SF nanocapsules composed of 50% SF showed an increased pH-responsive release for all tested model substances (Rhodamine B, Crystal Violet and Evans Blue) and methotrexate at the lowered pH of 4.5 to pH 5.4, while HSA capsules without SF did not show any pH-responsive drug release.
Mechanistic studies using confocal laser scanning microscopy (CLSM) and small angle X-ray scattering (SAXS) analyses showed that increases in particle porosity and decreases in particle densities are directly linked to pH-responsive release properties. Therefore, the pH-responsive release mechanism was identified as diffusion controlled in a novel and unique approach by linking scattering results with in-vitro studies. Finally, cytotoxicity studies using the human monocytic THP-1 cell line indicated non-toxic behavior of the drug loaded nanocapsules when applied in a concentration of 62.5 µg mL−1.
Based on the obtained release properties of HSA-SF nanocapsules formulations and the results of in-vitro MTT assays, formulations containing 50% SF showed the highest requirements arguing for future in vivo experiments and application in the treatment of inflammatory diseases.
Seven pyrene-labeled poly(oligo(ethylene glycol) methyl ether methacrylate)s (PyEG5-PEGnMAs) were prepared with n = 0, 3, 4, 5, 7, 9, and 19 ethylene glycol units by copolymerizing a small amount of ...penta(ethylene glycol) 1-pyrenemethyl ether methacrylate with an EGnMA monomer. The conformation of the PyEG5-PEGnMA polymers evolved from a random coil for PyEG5-PEG0MA or poly(methyl methacrylate) to a polymeric bottle brush (PBB) architecture with increasing side chain length. The fluorescence decays of the PyEG5-PEGnMA samples were fitted according to the fluorescence blob model (FBM) whose parameters were used, in combination with the Kratky–Porod equation, to calculate the persistence length of these polymers. The persistence lengths obtained from the PEF experiments were found to increase with the square of the number (NS) of non-hydrogen atoms in the side chain as expected theoretically. The persistence lengths found with the PyEG5-PEGnMA samples in DMF also matched those found earlier for another series of PEGnMA samples labeled with 1-pyrenebutanol. The good agreement found between the persistence lengths obtained with the PEGnMA samples labeled with two different pyrene derivatives illustrates the robustness of the method and its applicability for measuring the unknown persistence length of polydisperse polymer samples.
Against the backdrop of a global paper resource shortage, there is a growing need to identify fast-growing tree species capable of producing long-lasting paper. Three plant species namely
...Broussonetia kazinoki, Broussonetia papyrifera
and hybrid paper mulberry, belong to the
Broussonetia
genus, were collected from China to study their white bark suitability for pulp and papermaking. Their chemical composition revealed that the holocellulose content in
Broussonetia kazinoki
and
Broussonetia papyrifera
was more than 80%. The molecular weight distribution of several holocellulose/
α
-cellulose is observed by GPC, which allows us to better observe the changes of various components on the molecular weight. The yield, lignin, whiteness, and molecular weight of the pulps obtained by NaOH treatment were determined. Optical microscope was used to characterize the fiber length-width ratio and rigidity. Finally, the improvement of the fiber rigidity method based on the Kratky-Porod chain model makes it more theoretical and further reveals the influencing factors of fiber rigidity. This study demonstrates the high potentiality of these three species for papermaking applications.
The General Structure Analysis System II (GSAS‐II) now contains modules for the analysis of small‐angle X‐ray scattering data. This includes processing of two‐dimensional images to create corrected ...one‐dimensional patterns, analysis via maximum entropy or total nonnegative least‐squares methods of the size distribution, assuming polydispersity, in the dilute limit, and modeling of the one‐dimensional data with combinations of Guinier/Porod, Porod, both dilute and condensed populations of scattering objects, and Bragg scattering components; slit smearing corrections can be applied where needed. GSAS‐II can apply these modeling tools over a sequence of data collected while some experimental condition is varied. This sequential refinement result can then be subjected to a post refinement analysis to determine global parameters encompassing the entire experiment.
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