1,721,017 research outputs found
Development of new molecular tools for the characterization of human Granulosa cells: new implications for the research on human infertility
Full text linkNella routine della riproduzione assistita, la selezione degli ovociti si basa sulle loro caratteristiche
morfologiche, nonostante la scarsa correlazione tra tali parametri e la competenza dell’ovocita. Pertanto,
la ricerca si sta concentrando sull’identificazione di marker che possano supportare l’attuale metodica di
valutazione, in particolare studiando le cellule della Granulosa (GCs), che svolgono compiti fondamentali
all’interno del microambiente del follicolo: produzione di estradiolo e progesterone, regolazione
dell’avanzamento della meiosi e dell’attività trascrizionale dell’ovocita, produzione di nutrienti essenziali
per l’ovocita, e accumulo di metaboliti secreti. Pertanto, la progressione degli step della follicologenesi
dipende strettamente dalla comunicazione bidirezionale tra ovocita e le cellule somatiche che lo
circondano.
Lo studio delle GCs ha messo in luce molti aspetti circa le funzionalità ovariche, la follicologenesi, e i
meccanismi con cui fattori endogeni ed esogeni possono alterare questi delicati processi.
In questo senso, lo scopo principale del presente PhD è stato quello di caratterizzare le GCs, applicando
per la prima volta la tecnica Fourier Transform Infrared Microspectroscopy (FTIRM), in modo da
sviluppare un nuovo metodo per valutare la qualità degli ovociti umani. Questo potrebbe rappresentare
uno strumento nuovo, affidabile e oggettivo per la valutazione della qualità degli ovociti nella routine
della riproduzione assistita.
Oltre al tema principale, sono state applicate le tecniche FTIRM, Raman Microspectroscopy e qPCR per
studiare i meccanismi di intaccamento del metabolismo, della composizione biochimica e dell’attività
cellulare causati da fattori endogeni ed esogeni, in particolare l’invecchiamento riproduttivo,
l’endometriosi ovarica e inquinanti plastici.
Le informazioni ottenute su queste cellule contribuiscono alla comprensione dei meccanismi di
danneggiamento della follicologenesi, tramite un approccio multidisciplinare che ha visto l’accoppiamento
di analisi spettroscopiche e qPCR. Grazie ai risultati ottenuti, è stato proposto un approccio innovativo
per l’analisi della qualità degli ovociti tramite caratteristiche spettrali delle GCs, suggerendo la possibilità
di un’applicazione dell’FTIRM come strumento diagnostico di facile utilizzo nella routine di riproduzione
assistita.In assisted reproductive routine, oocyte selection is based on its morphological features, which seem not
to be related to its intrinsic competence. Hence, several efforts have been made to identify markers to be
added to the actual evaluation, in particular focusing on the crucial roles of Granulosa cells (GCs) in the
follicular microenvironment: production of estradiol and progesterone, regulation of the meiosis steps and
the transcriptional activity in the oocyte, production of essential nutrients for the oocyte, and
accumulation of secreted metabolites. Hence, the progression through the steps of folliculogenesis heavily
relies upon bi-directional interactions between germ cells and the surrounding somatic cells.
The study of GCs has shown to be determining to highlight particular features of ovarian mechanisms
and folliculogenesis, and also to identify the endogenous and exogenous factors that can impair these
delicate processes.
In this sense, the main aim of the PhD project was to characterize GCs, applying for the first time Fourier
Transform Infrared Microspectroscopy (FTIRM) to develop a method for evaluating the quality of human
oocytes. This could represent a new, reliable and objective tool for oocyte quality assessment in assisted
reproduction routine.
Besides this main topic, the impairment induced by endogenous and exogenous factors on the biochemical
composition, metabolism and cellular activity of GCs was also investigated by FTIRM, Raman
Microspectroscopy and qPCR, shedding new light on the mechanisms governing folliculogenesis. In
particular, the research was focused on the impairment determined by reproductive aging, ovarian
endometriosis, and plastic pollutants.
The information obtained on GCs contribute to the understanding of the mechanisms of impairment of
folliculogenesis, by a multidisciplinary approach made of spectroscopic analysis and qPCR. Thanks to the
results, an innovative approach to evaluate oocyte quality by spectral features of GCs was proposed,
suggesting the possibility to apply FTIRM as a clinical feasible diagnostic tool in assisted reproduction
routine
Breeders Age Affects Reproductive Success in Nothobranchius furzeri
No full textThe present study was conducted to examine, for the first time in Nothobranchius furzeri, the effects of mating in different aged breeders with particular emphasis on reproductive fitness and the effects of parental aging on offspring gametogenesis. In N. furzeri, the increase of maternal and paternal age is often a predictable indicator of the upcoming deterioration on their natural habitat (i.e., ephemeral puddles) during African dry season. We previously revealed that elderly parents respond to their physiological decline state by decelerating offspring's development and growth rate. In the present study, we focused on the effects of different age parents at the onset of female offspring's sexual maturity since interaction between growth and reproduction traits generally occurs in vertebrates and could represent a life strategy. For this purpose, four different age breeder groups were set up. The age-specific breeder differences in reproductive performance were examined by analyzing the reproductive age-related fitness, the gametogenesis process in F1 females by histology, the offspring oocytes quality analyzing the gene expression of age-related molecular markers, like sirt1 and foxo3a, and the biochemical composition of vitellogenic oocytes using a spectroscopic approach. Results suggest that both maternal and paternal age affect reproductive performance and could influence the onset of sexual maturity in female offspring. In conclusion, these findings highlighted the effects of parental aging on life history traits in the short-lived model N. furzeri. Our results suggested that the advanced sexual maturity in offspring from young parents could be related to an adaptive response to the temporary habitat conditions
Transport Properties of Self-Assembling G-Hydrogels: Evidence for a Tunable Fickian Diffusivity
Full text linkThe mixing of Guanosine (Gua) and Guanosine 5′-monophosphate (GMP) in water in selected compositions yields highly hydrated, transparent, and self-healing self-assembled supramolecular G-hydrogels, attractive for biomedical applications. This work investigates how hydrogel composition affects solute transport, including diffusion, binding, loading, and release properties, using a set of fluorescent probes with varying size and polarity. Although small/wide-angle X-ray scattering techniques showed that no structural changes are induced by probe addition, even when intercalation into G-quadruplexes is expected, the internal mesh structure of the hydrogel, modulated by the Gua:GMP ratio, directly impacts probe diffusivity and loading. Tighter networks (e.g., 1:1) slow diffusion and enhance retention compared to looser configurations (e.g., 1:4). Moreover, UV-visible titrations revealed markedly different binding affinities (Kb ≈ 5.7 × 104 M-1 for DAPI, 8.0 × 103 M-1 for ThT, and 1.4 × 102 M-1 for RhB), which are expected to result in lower diffusion coefficients and slower release, especially for DAPI and ThT. Indeed, diffusion coefficients, obtained via fluorescence recovery after photobleaching and time-resolved fluorescence spectroscopy, reach 90, 20, and 60 μm2/s for FITC-dextran, ThT, and RhB, respectively. Probe release kinetics, modeled via Weibull fitting, indicated sustained release with characteristic times (τ) between 9.6 and 23.2 h and β ≈ 1 in 1× PBS, consistent with predominantly Fickian diffusion. Remarkably, switching to 10× PBS significantly accelerated release (τ reduced by ≈ 40-50%), suggesting that ionic strength and/or pH changes critically affect not only probe-hydrogel interactions but also the internal gel architecture, altering porosity, mesh size, and network tortuosity, thus enhancing molecular mobility. Overall, the G-hydrogel system offers a structurally tunable and composition-dependent platform capable of finely regulating molecular transport and release profiles, making it highly suitable for controlled drug delivery and adaptive biomaterial applications
ATR-FTIR Analysis of Orthodontic Invisalign® Aligners Subjected to Various In Vitro Aging Treatments
Full text linkClear and removable tooth aligners for orthodontics treatments have become an increasingly popular alternative to fixed appliances. Even if protocols suggest removing aligners before eating or drinking, most patients retain them when they drink beverages. Alterations in the material during the daily use could determine a reduction in the application forces, affecting the desired orthodontic movement; the knowledge of how this material reacts when subjected to different aging processes is mandatory to establish the predictability of the orthodontic treatment. According to this, the aim of the present study was to assess a new objective approach, coupling spectroscopic and chemometric tools, to evaluate the changes occurring in Invisalign® aligners, the most widely used brand, exposed in vitro to coffee, tea, Coca Cola® and UV radiation for 24 and 48 h. In particular, ATR-FTIR spectroscopy was utilized to characterize, at the molecular level, the chemical and color modifications in the surfaces of the appliances; the obtained data were submitted to PCA and one-way ANOVA and Tukey’s multiple comparison test. Moreover, a colorimetry analysis was carried out to evaluate any changes in color and transparency. Coffee and tea samples displayed the major color changes between the tested groups. The differences highlighted in the spectral features of coffee, tea and UV-treated samples were mainly ascribable to color and transparency changes, because the chemical properties remained unaltered
Politiche pubbliche. Analisi e valutazione
No full textQuesto manuale innovativo tratta in modo integrato gli aspetti fondamentali delle politiche pubbliche. La prima parte dedicata all'analisi, la seconda ai metodi e all'evidenza empirica, la terza alla valutazione, mentre il capitolo conclusivo è dedicato alla progettazione istituzionale e alla deontologia. Il volume contiene scritti di Umberto Di Maggio, Efisio Espa, Giovanni Frazzica, Giuseppe Notarstefano, Valentina Punzo, Attilio Scaglione. https://www.mulino.it/isbn/978881528493
Guanosine hydrogels in focus: A comprehensive analysis through mid-infrared spectroscopy
Full text linkGuanosine nucleosides and nucleotides have the peculiar ability to self-assemble in water to form supramolecular complex architectures from G-quartets to G-quadruplexes. G-quadruplexes exhibit in turn a large liquid crystalline lyotropic polymorphism, but they eventually cross-link or entangle to form a densely connected 3D network (a molecular hydrogel), able to entrap very large amount of water (up to the 99% v/v). This high water content of the hydrogels enables tunable softness, deformability, self-healing, and quasi-liquid properties, making them ideal candidates for different biotechnological and biomedical applications. In order to fully exploit their possible applications, Attenuated Total Reflection-Fourier Transform InfraRed (ATR-FTIR) spectroscopy was used to unravel the vibrational characteristics of supramolecular guanosine structures. First, the characteristic vibrations of the known quadruplex structure of guanosine 5 '-monophosphate, '-monophosphate, potassium salt (GMP/K), were investigated: the identified peaks reflected both the chemical composition of the sample and the formation of quartets, octamers, and quadruplexes. Second, the role of K+ + and Na+ + cations in promoting the quadruplex formation was assessed: infrared spectra confirmed that both cations induce the formation of G-quadruplexes and that GMP/K is more stable in the G-quadruplex organization. Finally, ATR-FTIR spectroscopy was used to investigate binary mixtures of guanosine (Gua) and GMP/K or GMP/Na, both systems forming G-hydrogels. The same G-quadruplex-based structure was found in both mixtures, but the proportion of Gua and GMP affected some features, like sugar puckering, guanine vibrations, and base stacking, reflecting the known side-to-side aggregation and bundle formation occurring in these binary systems
ATR-FTIR, EDS and SEM evaluations of enamel structure after treatment with hydrogen peroxide bleaching agents loaded with nano-hydroxyapatite particles
Full text linkBackground
Tooth whitening is one of the most requested dental treatments, but it still presents some side effects. Indeed, the bleaching agent can generate patients’ discomfort and dental hard tissue damages, not achieving an efficient and long-lasting treatment with optimum whitening effect. To overcome these limitations, the bleaching agents containing nano-hydroxyapatite can represent a reliable solution to avoid these detrimental effects.
Methods
In this study, human third molars were treated with commercial bleaching agents, containing nano-hydroxyapatite (nHA) and 6% (at-home treatment), 12% and 18% (in-office treatments) of hydrogen peroxide (HP), named respectively G1, G2 and G3. The results were evaluated descriptively and analytically using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDS), comparing the treated groups with a commercial gel containing 10% carbamide peroxide (CONV) and with a non-treated control group (CTRL).
Results
ATR-FTIR analysis revealed a similar composition in carbonates and phosphates for CTRL, G1 and G2 groups, which showed no significant differences in their spectral profiles; an increased amount of organic matter was found in G3, while CONV displayed an intermediate behavior. SEM analysis did not highlight significant changes in the enamel microstructure of G1 and CONV when compared to CTRL; the pattern observed in G2 presented a slight increase of enamel irregularities, while G3 displayed a partial removal of the aprismatic layer and microporosities. No evident effects due to nHA were observed in the structure of the hydroxyapatite component of G1, G2 and CONV, if compared to CTRL, while G3 showed a slight loss of crystallinity. In all groups, EDS identified slight changes in the concentration of chemical elements O and Ca, while the Ca/P ratio was similar when compared to CTRL.
Conclusion
The obtained results suggest that the application of the tested commercial bleaching agents, with a concentration of HP up to 12%, does not alter the morphological and chemical composition of the enamel surface and maintains its crystallinity
Multidisciplinary evaluation of the remineralization potential of three fluoride-based toothpastes on natural white spot lesions.
Full text linkOBJECTIVES
This in vitro study aimed assessing the remineralization potential of three commercial fluoride-based toothpastes in permanent teeth with natural white spot lesions (WSLs). A multidisciplinary approach based on Raman microspectroscopy (RMS), Scanning electron microscopy (SEM), Energy-dispersive x-ray spectroscopy (EDS), and Vickers microhardness (VMH) was exploited.
METHODS
N = 12 human molars with natural WSLs in the proximal-vestibular zone were selected and divided into 4 groups (n = 3) according to the different treatments: HAF (hydroxyapatite with fluoride ions); SMF (sodium monofluorophosphate with arginine); SF (sodium fluoride with enzymes), and CTRL (untreated group). All toothpastes tested contained 1450 ppm of fluoride. Teeth samples were submitted to the following protocol: a 7-day pH cycling treatment, with two daily exposures (2 min each time) to the commercial toothpastes described above. The surface micromorphology (SEM), the chemical/elemental composition (RMS and EDS), and the Vickers microhardness (VMH) were evaluated. Statistical analysis was performed.
RESULTS
A remarkable remineralization of WSLs in SEM images was observed in all treated groups compared to CTRL. In particular, HAF and SF displayed higher values of VMH, phosphates amount (I960), crystallinity (FWHM960), and lower ones of C/P (I1070/I960) with respect to CTRL. Intermediate values were found in SMF, higher than CTRL but lower with respect to HAF and SF. As regards the Ca/P ratio, statistically significant differences (p < 0.05) were found between SF and the other groups.
CONCLUSIONS
All the tested dentifrices have shown to remineralize the WSLs. SF and HAF have comparable capability in hardness recovery and crystallinity; however, SF shows the best remineralizing potential according to both micromorphological and chemical analyses. Clinical relevance The daily use of toothpastes containing hydroxyapatite partially replaced with fluoride, sodium monofluorophosphate with arginine and sodium fluoride toothpaste associated with enzymes represents a preventive, therapeutic, effective, and non-invasive tool for remineralize WSLs
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