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1.
Chemphyschem ; 25(4): e202300590, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38093086

RESUMO

X-ray photoelectron spectroscopy (XPS) and reflection electron energy loss spectroscopy (REELS) were employed to characterize the electronic properties of Prussian blue (PB) and its analogs when electrodeposited over metal-decorated carbon nanotubes (CNTs). Through an investigation of the influence of carbon nanotubes (CNTs) and preparation conditions on the electronic structure, valuable insights were obtained regarding their effects on electrochemical properties. XPS analysis enabled the probing of the chemical composition and oxidation states of the film materials, unveiling synthesis-driven variations in their electronic properties. REELS provided information on energy loss and electronic transitions, enabling further characterization of the changes in the electronic structure induced by different preparation methods. Such findings emphasize the importance of surface characterization to understand how the unique electronic properties of such materials can be harnessed to enhance their performance and functionality.

2.
Int J Mol Sci ; 24(4)2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36834971

RESUMO

Diabetic neuropathy (DN) is one of the main microvascular complications of both type 1 and type 2 diabetes mellitus. Sometimes, this could already be present at the time of diagnosis for type 2 diabetes mellitus (T2DM), while it appears in subjects with type 1 diabetes mellitus (T1DM) almost 10 years after the onset of the disease. The impairment can involve both somatic fibers of the peripheral nervous system, with sensory-motor manifestations, as well as the autonomic system, with neurovegetative multiorgan manifestations through an impairment of sympathetic/parasympathetic conduction. It seems that, both indirectly and directly, the hyperglycemic state and oxygen delivery reduction through the vasa nervorum can determine inflammatory damage, which in turn is responsible for the alteration of the activity of the nerves. The symptoms and signs are therefore various, although symmetrical painful somatic neuropathy at the level of the lower limbs seems the most frequent manifestation. The pathophysiological aspects underlying the onset and progression of DN are not entirely clear. The purpose of this review is to shed light on the most recent discoveries in the pathophysiological and diagnostic fields concerning this complex and frequent complication of diabetes mellitus.


Assuntos
Diabetes Mellitus Tipo 2 , Neuropatias Diabéticas , Humanos , Diabetes Mellitus Tipo 2/complicações , Sistema Nervoso Autônomo , Dor/complicações
3.
Phys Chem Chem Phys ; 24(29): 17852-17861, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35851795

RESUMO

Several strategies have been considered in search of more efficient organic materials for charge transfer in photovoltaic devices. Among them, the integration of donor-acceptor (D-A) functional units on a conjugated copolymer has been widely applied. In this framework, we evaluated four terpolymers made up of donor moieties derived from 9,9-dioctylfluorene and 9-(heptadecan-9-yl)-9H-carbazole combined with 2,1,3-benzothiadiazole, the acceptor moiety, in different monomer ratios and polymerization routes (block and random microstructures). The preferred molecular orientation and charge transfer dynamics of the polymeric films were assessed by near edge X-ray absorption fine structure spectroscopy (NEXAFS) and resonant Auger electron spectroscopy (RAES) around the sulfur K-edge. Charge transfer times (τCT) were estimated by the Core-Hole Clock (CHC) method. Films with a high degree of organization were identified for the block terpolymer and random terpolymers with uneven amounts of donor units, showing a preferred orientation of the benzothiadiazole (BT) molecular plane parallel to the substrate surface. The values of τCT measured for all terpolymers were higher than those for typical polymers used in photovoltaic devices, which is not desirable for this type of optoelectronic application, but this may be correlated to the strong acceptor character of BT, the unit probed. To investigate the effect of film formation on the excited state behavior, steady-state and time-resolved photoluminescence measurements were also conducted. X-ray photoelectron spectroscopy (XPS) was employed to characterize the surface chemical composition of the terpolymer films. Based on the spectroscopic data the block copolymer appears to be the most suitable for the desired application.

4.
Phys Chem Chem Phys ; 24(14): 8477-8487, 2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35404373

RESUMO

We propose a novel approach for an indirect probing of conjugation and hyperconjugation in core-excited molecules using resonant Auger spectroscopy. Our work demonstrates that the changes in the electronic structure of thiophene (C4H4S) and thiazole (C3H3NS), occurring in the process of resonant sulfur K-shell excitation and Auger decay, affect the stabilisation energy resulting from π-conjugation and hyperconjugation. The variations in the stabilisation energy manifest themselves in the resonant S KL2,3L2,3 Auger spectra of thiophene and thiazole. The comparison of the results obtained for the conjugated molecules and for thiolane (C4H8S), the saturated analogue of thiophene, has been performed. The experimental observations are interpreted using high-level quantum-mechanical calculations and the natural bond orbital analysis.

5.
BMC Musculoskelet Disord ; 22(Suppl 2): 1069, 2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36100879

RESUMO

BACKGROUND: Extracapsular proximal femur metastasis could be treated by synthesis or resection and megaprosthesis. No universal accepted guidelines are present in the literature. The aim of our study is to analyze of patients with metastases in the trochanteric region of the femur treated by a single type of intramedullary nailing or hip megaprosthesis. METHODS: We retrospectively reviewed all patients affected by extracapsular metastases of proximal femur. Anthropometric and anamnestic data, routine blood exams and complications were collected. VAS score and MSTS score was administered before the surgery, ad 1-6-12 months after surgery. An un-paired T test and Chi-square were used. Multiple linear regression and logistic regression was performed. Significance was set for p < 0.05. RESULT: Twenty patients were assigned in intramedullary Group, twenty-five in megaprostheses Group. The mean operative time is shorter in intramedullary group. Differential shows a higher anemization in megaprostheses group (2 ± 2 vs 3.6 ± 1.3; p = 0.02). The patients of intramedullary group showed malnutrition (Albumin: 30.5 ± 6.5 vs 37.6 ± 6 g/L; p = 0.03) and pro-inflammatory state (NLR: 7.1 ± 6.7 vs 3.8 ± 2.4; p = 0.05) (PLR: 312 ± 203 vs 194 ± 99; p = 0.04) greater than megaprostheses group. The patients in intramedullary groups shows a higher functional performance score than megaprostheses group at 1 month follow-up (MSTS: 16.4 ± 6.3 vs 12.2 ± 3.7; p = 0.004). A multivariate analysis confirms the role of type of surgery (p = 0.001), surgery duration (p = 0.005) and NLR (p = 0.02) in affecting the MSTS. Globally eight complications were recorded, no statistical difference was noticed between the two groups (p = 0.7), no predictor was found at logistic analysis. CONCLUSION: Intramedullary nailing guarantees a rapid functional recovery, compared to patients undergoing hip megaprosthesis who instead improve gradually over time. The selection of patients with poor prognosis allows the correct surgical indication of nailing, while in the case of a more favorable prognosis, the intervention of hip megaprosthesis is to be preferred.


Assuntos
Fixação Intramedular de Fraturas , Fêmur/cirurgia , Fixação Intramedular de Fraturas/efeitos adversos , Humanos , Extremidade Inferior , Estudos Retrospectivos , Resultado do Tratamento
6.
Int J Mol Sci ; 23(11)2022 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-35683016

RESUMO

Corroborating data sustain the pleiotropic effect of nerve growth factor (NGF) in the protection of the visual system from dangerous stimuli, including ultraviolet (UV). Since UV exposure might promote ocular surface changes (conjunctival inflammation and matrix rearrangement), as previously reported from in vivo studies sustaining some protective NGF effects, in vitro cultures of human conjunctival fibroblasts (FBs) were developed and exposed to a single UV exposure over 15 min (0.277 W/m2), either alone or supplemented with NGF (1-10-100 ng/mL). Conditioned media and cell monolayers were collected and analyzed for protein release (ELISA, ELLA microfluidic) and transcript expression (real-time PCR). A specific "inflammatory to remodeling" pattern (IL8, VEGF, IL33, OPN, and CYR61) as well as a few epigenetic transcripts (known as modulator of cell differentiation and matrix-remodeling (DNMT3a, HDAC1, NRF2 and KEAP1)) were investigated in parallel. UV-exposed FBs (i), showed no proliferation or significant cytoskeleton rearrangement; (ii), displayed a trkANGFR/p75NTR phenotype; and (iii), synthesized/released IL8, VEGF-A, IL33, OPN, and CYR61, as compared to unexposed ones. NGF addition counteracted IL8, IL33, OPN, and CYR61 protein release merely at lower NGF concentrations but not VEGF. NGF supplementation did not affect DNMT3a or HDAC1 transcripts, while it significantly upregulated NRF2 at lowest NGF doses and did not change KEAP1 expression. Taken together, a single UV exposure activated conjunctival FBs to release pro-inflammatory/fibrogenic factors in association with epigenetic changes. The effects were selectively counteracted by NGF supplementation in a dose-dependent fashion, most probably accountable to the trkANGFR/p75NTR phenotype. Further in vitro studies are underway to better understand this additional NGF pleiotropic effect. Since UV-shield impairments represent a worldwide alert and UV radiation can slowly affect ocular surface homeostasis (photo-ageing, cataract) or might exacerbate ocular diseases with a preexisting fibrosis (pterygium, VKC), these findings on NGF modulation of UV-exposed FBs might provide additional information for protecting the ocular surface (homeostasis) from low-grade long-lasting UV insults.


Assuntos
Fator de Crescimento Neural , Receptor trkA , Fibroblastos/metabolismo , Humanos , Interleucina-33/metabolismo , Interleucina-8/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Fator de Crescimento Neural/metabolismo , Receptor de Fator de Crescimento Neural/metabolismo , Receptor trkA/metabolismo , Receptores de Fator de Crescimento Neural/metabolismo
7.
Adv Exp Med Biol ; 1331: 255-263, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34453304

RESUMO

Nerve growth factor (NGF) is a neuroprotective molecule performing not only on central and peripheral neurons but also on cells of the visual system. Human retinitis pigmentosa (RP) is a major cause of blindness worldwide, and a resolute therapy is still lacking. Recent studies have shown that ocular NGF administration exerts a protective action on damaged retinal cells of mammalians, including human beings, although whether NGF also protects photoreceptors is not clear.We used the Royal College of Surgeons (RCS) strain in this study. The RCS is a rodent affected by inherited retinitis pigmentosa (RP) during postnatal life. For this study, we investigated whether ocular NGF treatment reduces/stops the progression of photoreceptor degeneration of rats with RP.This study was carried out in vitro on isolated photoreceptors to further investigate the action on these cells and whether the action is direct or mediated.The results indicate that ocular NGF administration can protect photoreceptors from degeneration into a model developing inherited RP and that the NGF action is direct. In this regard, we observed that binding of NGF to its receptor modulates expression of rhodopsin, a specific biological marker for photoreceptor survival and functionality.Part of the data reported in this chapter has been published in a previous study.


Assuntos
Degeneração Retiniana , Retinose Pigmentar , Animais , Modelos Animais de Doenças , Fator de Crescimento Neural/genética , Células Fotorreceptoras , Ratos , Retinose Pigmentar/tratamento farmacológico , Retinose Pigmentar/genética , Rodopsina/genética
8.
Eur J Orthop Surg Traumatol ; 31(3): 579-585, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33068166

RESUMO

The entrapment of the ulnar nerve in Guyon's canal (GC) is a well-known wrist canalicular syndrome which is usually followed by a gradual combination of both sensitive and motor symptomatology. However, GC nerve compression could also cause a pure hand motor dysfunction. This condition, less frequent than the classic Guyon's syndrome, can be difficult to diagnose. Authors report a case series of eight patients affected by isolated compression of the ulnar nerve motor branch, due to piso-triquetrum or triquetro-hamate joint ganglia. Surgical technique and postoperative outcomes are discussed in this paper. The isolated compression of the ulnar nerve motor branch is a very rare clinical condition which is often linked to several causes. The rarity of the pathology is probably due to lack of knowledge and therefore to the difficulty in formulating a correct diagnosis. Surgical treatment appears to be decisive in most cases, although late diagnosis often leads to incomplete functional recovery.


Assuntos
Articulações do Carpo , Síndromes de Compressão do Nervo Ulnar , Gânglios , Humanos , Nervo Ulnar , Síndromes de Compressão do Nervo Ulnar/diagnóstico por imagem , Síndromes de Compressão do Nervo Ulnar/etiologia , Síndromes de Compressão do Nervo Ulnar/cirurgia , Punho/cirurgia , Articulação do Punho/diagnóstico por imagem , Articulação do Punho/cirurgia
9.
Phys Chem Chem Phys ; 22(35): 19923-19931, 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32856622

RESUMO

In this study, we investigate two copolymers as electron donors in photovoltaic devices, PFO-DBT (poly[2,7-(9,9-dioctylfluorene)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole]) and its analogue with Si, PSiF-DBT (poly[2,7-(9,9-dioctyl-dibenzosilole)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole]). The results discussed here are related to the influence of heavy atoms on the electrical and morphological properties of the devices. Charge transfer dynamics in the polymeric films were evaluated using the core-hole clock method. Besides that, using density functional theory (DFT) and time-dependent DFT (TD-DFT) methods, we investigate the electronic structure and charge transfer properties of the two systems. The charge transfer rates were estimated in the framework of the semiclassical Marcus/Hush theory. We found that the better stacking between the polymer chains for PSiF-DBT provides higher solar absorption capacity in regions of higher wavelengths and faster hole transfer rates. We also obtain a faster electron transfer rate at the PSiF-DBT/C60 interface compared to the PFO-DBT/C60 interface that is mainly related to the difference in the driving force between the two systems. These features help to explain why the organic photovoltaic devices using PSiF-DBT as the active layer exhibited a higher performance compared to devices using PFO-DBT. Here, we show that our results are able to provide important insights about the parameters that can influence the photovoltaic performance of the devices.

10.
J Phys Chem A ; 124(34): 6845-6855, 2020 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-32702984

RESUMO

Ionization and fragmentation pathways induced by ionizing agents are key to understanding the formation of complex molecules in astrophysical environments. Acetonitrile (CH3CN), the simplest organic nitrile, is an important molecule present in the interstellar medium. In this work, DFT and MP2 calculations were performed in order to obtain the low energy structures of the most relevant cations formed from electron-stimulated ion desorption of CH3CN ices. Selected reaction pathways and spectroscopic properties were also calculated. Our results indicate that the most stable acetonitrile cation structure is CH2CNH+ and that hydrogenation can occur successively without isomerization steps until its complete saturation. Moreover, the stability of distinct cluster families formed from the interaction of acetonitrile with small fragments, such as CHn+, C2Hn+, and CHnCNH+, is discussed in terms of their respective binding energies. Some of these molecular clusters are stabilized by hydrogen bonds, leading to species whose infrared features are characterized by a strong redshift of the N-H stretching mode. Finally, the rotational spectra of CH3CN and protonated acetonitrile, CH3CNH+, were simulated using distinct computational protocols based on DFT, MP2, and CCSD(T) considering centrifugal distortion, vibrational-rotational coupling, and vibrational anharmonicity corrections. By adopting an empirical scaling procedure for calculating spectroscopic parameters, we were able to estimate the rotational frequencies of CH3CNH+ with an expected average error below 1 MHz for J values up to 10.

11.
Phys Chem Chem Phys ; 21(2): 736-743, 2019 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-30543327

RESUMO

The conducting polymer, poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid (PEDOT:PSS), is certainly one of the most important substitute materials for indium tin oxide in organic devices. Its metallic conductivity and transmittance bring favorable perspectives for organic photovoltaic applications. Although graphene oxide (GO) is not a good conductor, it can form high-quality thin films and can be transparent, and additionally, GO is an inexpensive material and can be easily synthesized. This study investigated how the conductivity of a composite film of graphene oxide (GO) and different amounts of PEDOT:PSS can be modified. The effects of GO:PEDOT:PSS composites with several PEDOT:PSS proportions were analyzed in regards to the composite molecular structure and ordering, charge transfer dynamics (in the femtosecond range), electrical properties and morphology. For the best conductivity ratio GO found with 5% PEDOT:PSS, a solvent treatment was also performed, comparing the resistivity of the film when treated with dimethyl sulfoxide (DMSO) and with ethylene glycol.

12.
Phys Chem Chem Phys ; 20(40): 25762-25771, 2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30283941

RESUMO

We report on direct measurement of all major ion-fragments and cluster-ions formed during high-energy electron impact of 2 keV on gaseous and condensed-phase pyridine. The ion-fragments of the parent pyridine cation are discussed in groups according to the number of atoms from the aromatic ring. The ion yield distributions within these groups show significant shifts towards higher masses for condensed pyridine compared to gaseous pyridine due to hydrogen migration. A wide spectrum of desorbed hydrogenated fragment-ions and ionic clusters with masses up to 320 u are observed for pyridine. The ion yields for the protonated parent molecule (C5H5NH+), the dehydrogenated dimer (C10H9N2+) and the dehydrogenated trimer (C15H12N3+) depend on the mass of the desorbing ionic clusters. The strongest cluster signals are assigned to binding between the parent cation and subunits of the pyridine molecule. Quantum-chemical calculations reveal that the formation of a bond between the pyridine molecules and a carbenium ion is crucial for the stability of selected cluster ions.

13.
Graefes Arch Clin Exp Ophthalmol ; 256(4): 729-738, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29450621

RESUMO

PURPOSE: Based on evidence that nerve growth factor (NGF) exerts healing action on damaged corneal, retinal, and cutaneous tissues, the present study sought to assess whether topical NGF application can prevent and/or protect epithelial cells from deleterious effects of ultraviolet (UV) radiation. METHODS: Eyes from 40 young-adult Sprague Dawley rats and cutaneous tissues from 36 adult nude mice were exposed to UVA/B lamp for 60 min, either alone or in the presence of murine NGF. Corneal, retinal, and cutaneous tissues were sampled/processed for morphological, immunohistochemical, and biomolecular analysis, and results were compared statistically. RESULTS: UV exposure affected both biochemical and molecular expression of NGF and trkANGFR in corneal, retinal, and cutaneous tissues while UV exposure coupled to NGF treatment enhanced NGF and trkANGFR expression as well as reduced cell death. CONCLUSIONS: Overall, the findings of this in vivo/ex vivo study show the NGF ability to reduce the potential UV damage. Although the mechanism underneath this effect needs further investigation, these observations prospect the development of a pharmacological NGF-based therapy devoted to maintain cell function when exposed to phototoxic UV radiation.


Assuntos
Córnea/metabolismo , Doenças da Córnea/genética , Regulação da Expressão Gênica/efeitos da radiação , Fator de Crescimento Neural/genética , Retina/metabolismo , Doenças Retinianas/genética , Pele/metabolismo , Animais , Contagem de Células , Sobrevivência Celular , Células Cultivadas , Córnea/patologia , Doenças da Córnea/metabolismo , Doenças da Córnea/patologia , Modelos Animais de Doenças , Relação Dose-Resposta à Radiação , Feminino , Masculino , Camundongos , Camundongos Nus , Microscopia Confocal , Fator de Crescimento Neural/biossíntese , Ratos , Ratos Sprague-Dawley , Retina/patologia , Doenças Retinianas/metabolismo , Doenças Retinianas/patologia , Pele/patologia , Raios Ultravioleta/efeitos adversos
14.
J Phys Chem A ; 121(21): 4114-4122, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28449576

RESUMO

The room temperature dissociative recombination of ions formed in an acetone/argon plasma has been studied using the flowing afterglow Langmuir probe-mass spectrometer method. By changing the concentration of acetone density, it is possible to have a plasma dominated by different types of ions (fragments, adducts, and dimer ions). The application of these measurements to astrophysical plasmas is discussed.

15.
Graefes Arch Clin Exp Ophthalmol ; 255(3): 567-574, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28013393

RESUMO

PURPOSE: Our previous study highlighted the potential nerve growth factor (NGF) effect on damaged photoreceptors from a rat model of spontaneous Retinitis Pigmentosa (RP). Herein, we tested the combined NGF/anti-vascular endothelial growth factor (αVEGF) effect on cultured retinal cells isolated from Royal College of Surgeons (RCS) rats receiving an intravitreal VEGF injection (iv-VEGF) to exacerbate retinal inflammation/neovascularization. METHODS: RCS (n = 75) rats were equally grouped as untreated (n = 25), iv-saline (single saline intravitreal injection; n = 25) and iv-VEGF (single VEGF intravitreal injection; n = 25). Morphological and biochemical analysis or in vitro stimulations with the biomolecular investigation were carried out on explanted retinas. Isolated retinal cells were treated with NGF and αVEGF, either alone or in combination, for 6 days and cells were harvested for morphological and biomolecular analyses. RESULTS: Infiltrating inflammatory cells were detected in iv-VEGF exposed RCS retinas, indicative of exacerbated inflammation and neovascularization. In cell cultures, NGF/αVEGF significantly increased retinal cell survival as well as rhodopsin expression and neurite outgrowth in photoreceptors. Particularly, NGF/αVEGF upregulated Bcl-2 mRNA, downregulated Bax mRNA, upregulated trkANGFR mRNA and finally upregulated both NGF mRNA and protein. CONCLUSIONS: These data confirm and extend our previous findings on NGF-photoreceptor crosstalk, highlighting that the NGF/αVEGF combination might be an interesting approach for improving neuroprotection of RCS retinal cells and likewise photoreceptors in the presence of neovascularization. Further studies are required to translate this in vitro approach into clinical practice.


Assuntos
Bevacizumab/administração & dosagem , Fator de Crescimento Neural/farmacologia , Células Fotorreceptoras de Vertebrados/patologia , Retinose Pigmentar/tratamento farmacológico , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Inibidores da Angiogênese/administração & dosagem , Animais , Animais Recém-Nascidos , Apoptose , Sobrevivência Celular , Células Cultivadas , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Injeções Intravítreas , Masculino , Microscopia Confocal , Células Fotorreceptoras de Vertebrados/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA/genética , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Retinose Pigmentar/genética , Retinose Pigmentar/metabolismo
16.
Nanotechnology ; 27(28): 285401, 2016 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-27251109

RESUMO

Hydrogen fuels generated by water splitting using a photocatalyst and solar irradiation are currently gaining the strength to diversify the world energy matrix in a green way. CdS quantum dots have revealed a hydrogen generation improvement when added to TiO2 materials under visible-light irradiation. In the present paper, we investigated the performance of TiO2 nanotubes coupled with CdS quantum dots, by a molecular bifunctional linker, on photocatalytic hydrogen generation. TiO2 nanotubes were obtained by anodization of Ti foil, followed by annealing to crystallize the nanotubes into the anatase phase. Afterwards, the samples were sensitized with CdS quantum dots via an in situ hydrothermal route using 3-mercaptopropionic acid as the capping agent. This sensitization technique permits high loading and uniform distribution of CdS quantum dots onto TiO2 nanotubes. The XPS depth profile showed that CdS concentration remains almost unchanged (homogeneous), while the concentration relative to the sulfate anion decreases by more than 80% with respect to the initial value after ∼100 nm in depth. The presence of sulfate anions is due to the oxidation of sulfide and occurs in greater proportion in the material surface. This protection for air oxidation inside the nanotubular matrix seemingly protected the CdS for photocorrosion in sacrificial solution leading to good stability properties proved by long duration, stable photocurrent measurements. The effect of the size and the distribution of sizes of CdS quantum dots attached to TiO2 nanotubes on the photocatalytic hydrogen generation were investigated. The experimental results showed three different behaviors when the reaction time of CdS synthesis was increased in the sensitized samples, i.e. similar, deactivation and activation effects on the hydrogen production with regard to TiO2 nanotubes. The deactivation effect was related to two populations of sizes of CdS, where the population with a shorter band gap acts as a trap for the electrons photogenerated by the population with a larger band gap. Electron transfer from CdS quantum dots to TiO2 semiconductor nanotubes was proven by the results of UPS measurements combined with optical band gap measurements. This property facilitates an improvement of the visible-light hydrogen evolution rate from zero, for TiO2 nanotubes, to approximately 0.3 µmol cm(-2) h(-1) for TiO2 nanotubes sensitized with CdS quantum dots.

17.
Phys Chem Chem Phys ; 18(19): 13693-700, 2016 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-27140434

RESUMO

We have investigated diindenoperylene (DIP) thin films deposited on Au(110) single crystals, by using a multi-technique approach based on X-ray photoemission spectroscopy (XPS), resonant photoemission spectroscopy (RPES), near edge X-ray absorption fine structure (NEXAFS) spectroscopy, atomic force microscopy (AFM) and photoemission electron microscopy (PEEM). DIP molecules are physisorbed on gold, with image-charge screening playing the major role as an interface phenomenon. DIP thin films show Stranski-Krastanov growth mode and the structural herringbone arrangement mimics the arrangement found in DIP single crystals. These results are common with the (100) and (111) gold substrate geometries. On the contrary, the island aggregation is substrate geometry-dependent. This paves the way to exploit the degree of anisotropy in different lattice geometries as a tool for molecular patterning of inorganic surfaces, keeping the electronic structure preserved.

18.
Growth Factors ; 33(5-6): 401-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26728403

RESUMO

Nerve growth factor (NGF) exerts protective actions in the healthy and diseased nervous system. Intranasal administration is a suitable and safe strategy to deliver NGF to CNS neurons. We investigated whether nasal anti-NGF-antibody (ANA) administration affects neuronal autophagy, in view of its putative regulatory role in this process. We focused on olfactory bulbs (OB), neocortex (Cx), hippocampus (HF) and septal complex (SC), known to be NGF-responsive and autophagically active. Our combined molecular/morphological results demonstrate that intranasally administered ANA reaches brain NGF-target neurons and lowers the levels of endogenous NGF and its receptors. Treatment also affects - in a brain region-dependent manner - the expression of the autophagic proteins Beclin-1 and Ambra1, as well as that of proteins belonging to the Bcl2 family, namely Bax and Bcl-2, reflecting apoptotic dysregulation. This study provides a nongenetically modified, NGF-defective animal model, representing a suitable tool to investigate novel properties of the neurotrophin, especially in relation to autophagy.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/biossíntese , Anticorpos/imunologia , Proteínas Reguladoras de Apoptose/biossíntese , Autofagia/fisiologia , Fator de Crescimento Neural/metabolismo , Administração Intranasal , Animais , Anticorpos/administração & dosagem , Proteína Beclina-1 , Linhagem Celular Tumoral , Hipocampo/metabolismo , Neocórtex/metabolismo , Fator de Crescimento Neural/imunologia , Bulbo Olfatório/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Ratos , Receptores de Fator de Crescimento Neural/metabolismo , Proteína X Associada a bcl-2/biossíntese
19.
Phys Chem Chem Phys ; 17(17): 11244-51, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-25836380

RESUMO

Ultrafast charge delocalization dynamics in an internal donor-acceptor copolymer poly(9,9-dioctylfluorenyl-co-bithiophene) (F8T2) and its blend with the fullerene derivative [6,6]-phenyl C61 butyric acid methyl ester (PCBM) was studied by resonant Auger spectroscopy measured around sulfur K-edge using the core-hole clock approach. The effect of thermal annealing on the charge transfer delocalization times (τCT) was also investigated. Two main transitions with S 1s → π* and S 1s → σ*(S-C) character were measured at the S 1s NEXAFS spectra. Poor charge delocalization was observed for as cast polymeric films at photon energies corresponding to the S 1s → π* transition, which may suggest a weak π-electronic coupling due to weak polymer crystallinity and chain stacking. Enhancement in the charge transfer process for photon energies close to the resonance maximum was observed for thermally annealed F8T2 and its blends. Atomic Force Microscopy (AFM) topography for as cast F8T2:PCBM shows a top position of PCBM units relative to the polymer, homogeneously distributed on the film surface. This configuration improves the charge delocalization through S 1s → π* molecular orbitals for the as cast blended film, suggesting a strong π-electronic coupling. A new rearrangement of F8T2:PCBM film was found after thermal annealing, leading to a more efficient electron transfer channel through σ* molecular orbitals.

20.
Healthcare (Basel) ; 12(2)2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38255043

RESUMO

(1) Background: Mobile health (mHealth) solutions can become a means of improving functional recovery and reducing the peri-operative burden and costs associated with arthroplasty procedures. The aim of this study is to explore the objectives, functionalities, and outcomes of a platform designed to provide personalized surgical experiences to qualified patients, along with the associated problems and opportunities. (2) Methods: A survey-based analysis was conducted on patients who were prescribed the use of a specific care management platform and underwent primary robotic total knee arthroplasty (rTKA) between January 2021 and February 2023. (3) Results: Patients registered on the platform who have undergone primary robotic TKA (rTKA) were considered. The mean age of registered patients is 68.6 years. The male (M)/female (F) ratio is 45.1%/54.9%. The patients interviewed were at an average distance of 485 days from the intervention, with a standard deviation of 187.5. The survey highlighted appreciation for the app and its features, but also limitations in its use and in its perception by the patients. All these data were evaluated according to the Wald principles and strategies to improve patient recruitment, enhance adherence, and create a comprehensive patient journey for optimized surgical experiences. (4) Conclusions: This patient care platform may have the potential to impact surgical experiences by increasing patient engagement, facilitating remote monitoring, and providing personalized care. There is a need to emphasize the importance of integrating the recruiting process, improving adherence strategies, and creating a comprehensive patient journey within the platform.

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