268 research outputs found
Experimental generation of complex noisy photonic entanglement
We present an experimental scheme based on spontaneous parametric
down-conversion to produce multiple photon pairs in maximally entangled
polarization states using an arrangement of two type-I nonlinear crystals. By
introducing correlated polarization noise in the paths of the generated photons
we prepare mixed entangled states whose properties illustrate fundamental
results obtained recently in quantum information theory, in particular those
concerning bound entanglement and privacy.Comment: 12 pages, 3 figure
Evaluation of mechanical and interfacial properties of bio-composites based on poly(lactic acid) with natural cellulose fibers
The circular economy policy and the interest for sustainable material are inducing a constant expansion of the bio-composites market. The opportunity of using natural fibers in bio-based and biodegradable polymeric matrices, derived from industrial and/or agricultural waste, represents a stimulating challenge in the replacement of traditional composites based on fossil sources. The coupling of bioplastics with natural fibers in order to lower costs and promote degradability is one of the primary objectives of research, above all in the packaging and agricultural sectors where large amounts of non-recyclable plastics are generated, inducing a serious problem for plastic disposal and potential accumulation in the environment. Among biopolymers, poly(lactic acid) (PLA) is one of the most used compostable, bio-based polymeric matrices, since it exhibits process ability and mechanical properties compatible with a wide range of applications. In this study, two types of cellulosic fibers were processed with PLA in order to obtain bio-composites with different percentages of microfibers (5%, 10%, 20%). The mechanical properties were evaluated (tensile and impact test), and analytical models were applied in order to estimate the adhesion between matrix and fibers and to predict the material's stiffness. Understanding these properties is of particular importance in order to be able to tune and project the final characteristics of bio-composites
Electrosprayed shrimp and mushroom nanochitins on cellulose tissue for skin contact application
Cosmetics has recently focused on biobased skin-compatible materials. Materials from natural sources can be used to produce more sustainable skin contact products with enhanced bioactivity. Surface functionalization using natural-based nano/microparticles is thus a subject of study, aimed at better understanding the skin compatibility of many biopolymers also deriving from biowaste. This research investigated electrospray as a method for surface modification of cellulose tissues with chitin nanofibrils (CNs) using two different sources—namely, vegetable (i.e., from fungi), and animal (from crustaceans)—and different solvent systems to obtain a biobased and skin-compatible product. The surface of cellulose tissues was uniformly decorated with electrosprayed CNs. Biological analysis revealed that all treated samples were suitable for skin applications since human dermal keratinocytes (i.e., HaCaT cells) successfully adhered to the processed tissues and were viable after being in contact with released substances in culture media. These results indicate that the use of solvents did not affect the final cytocompatibility due to their effective evaporation during the electrospray process. Such treatments did not also affect the characteristics of cellulose; in addition, they showed promising anti-inflammatory and indirect antimicrobial activity toward dermal keratinocytes in vitro. Specifically, cellulosic substrates decorated with nanochitins from shrimp showed strong immunomodulatory activity by first upregulating then downregulating the pro-inflammatory cytokines, whereas nanochitins from mushrooms displayed an overall anti-inflammatory activity via a slight decrement of the pro-inflammatory cytokines and increment of the anti-inflammatory marker. Electrospray could represent a green method for surface modification of sustainable and biofunctional skincare products
Radiological risk from thoron, a case study: The particularly radon-prone area of Bolsena, and the lesson learned
Abstract The contribution of 220 Rn is usually negligible compared to that of 222 Rn: its very short half-life makes escape from its source site within the rock very unlikely and it never has time enough to filtrate through the ground and through cracks in the floors or cellar walls to reach living quarters. This however becomes untrue if walls built with 232 Th-rich materials are present: then sizeable amounts of thoron may be detected in the closed areas bounded by those walls. This is the case for many dwellings in central Italy, and the town of Bolsena (northern Latium) is presented as a case study. A typical building of the area, entirely constructed with tuff blocks, is investigated and the annual dose rates calculated for varying distances from the wall. Thoron concentration was found to decrease with a relaxation length of 13 cm. Thoron was found to pose a significant risk. The rate of air exchange was found to produce little effect. Wall plastering acts as a filter: thoron diffuses through it but a HVL of less than 1 cm was found to prevail
Chitin and Its Derivatives: Nanostructured Materials from Different Marine and Terrestrial Sources
Chitin is a very abundant polysaccharide that can be obtained from well-known marine sources (crustaceans), but also from terrestrial sources (mushrooms and insects). In the case where animal sources are considered, the material can be obtained by much abundant food or feeding waste. The extraction methodologies were not developed with similar technical readiness levels considering the different sources and the further conversion to chitin nanofibrils and chitosan is also under study, enabling the production of products differentiated for their macromolecular structures and morphology.Chitin nanofibrils from sea food sources were used in sanitary, cosmetic and packaging applications, where their anti-microbial properties and good biocompatibility were very useful. Chitin from mushrooms and sea food was used as starting material in possible coatings for cellulosic and bioplastic substrates. Currently chitin from insects (Hermetia Illucens) is also under study as well as the methodologies for extracting derivatives from it. Infrared analysis is an interesting technique to compare chitins, chitin nanofibrils and chitosan from different sources as well as electron microscopy for studying their morphology. The derivatives of chitin, such as chitosan and chitin nanofibrils, show anti-microbial properties. Hence, their use in several applications, ranging from packaging to sanitary and cosmetics, can conjugate high performance novel products with a reduced environmental concern. The comparison between chitin derivatives from different sources is very useful to address the biopolymers to specific applications, including the agricultural sector. While more and more applications for chitin derivatives will be developed, differences between them should be clarified and correlated to the sources, the methodologies of their production and their physical-chemical properties
Inhibition of Interferon-Gamma-Stimulated Melanoma Progression by Targeting Neuronal Nitric Oxide Synthase (nNOS)
Interferon-gamma (IFN-γ) is shown to stimulate melanoma development and progression. However, the underlying mechanism has not been completely defined. Our study aimed to determine the role of neuronal nitric oxide synthase (nNOS)-mediated signaling in IFN-γ-stimulated melanoma progression and the anti-melanoma effects of novel nNOS inhibitors. Our study shows that IFN-γ markedly induced the expression levels of nNOS in melanoma cells associated with increased intracellular nitric oxide (NO) levels. Co-treatment with novel nNOS inhibitors effectively alleviated IFN-γ-activated STAT1/3. Further, reverse phase protein array (RPPA) analysis demonstrated that IFN-γ induced the expression of HIF1α, c-Myc, and programmed death-ligand 1 (PD-L1), in contrast to IFN-α. Blocking the nNOS-mediated signaling pathway using nNOS-selective inhibitors was shown to effectively diminish IFN-γ-induced PD-L1 expression in melanoma cells. Using a human melanoma xenograft mouse model, the in vivo studies revealed that IFN-γ increased tumor growth compared to control, which was inhibited by the co-administration of nNOS inhibitor MAC-3-190. Another nNOS inhibitor, HH044, was shown to effectively inhibit in vivo tumor growth and was associated with reduced PD-L1 expression levels in melanoma xenografts. Our study demonstrates the important role of nNOS-mediated NO signaling in IFN-γ-stimulated melanoma progression. Targeting nNOS using highly selective small molecular inhibitors is a unique and effective strategy to improve melanoma treatment
Liquid and solid functional bio-based coatings
The development of new bio-based coating materials to be applied on cellulosic and plastic based substrates, with improved performances compared to currently available products and at the same time with improved sustainable end of life options, is a challenge of our times. Enabling cellulose or bioplastics with proper functional coatings, based on biopolymer and functional materials deriving from agro-food waste streams, will improve their performance, allowing them to effectively replace fossil products in the personal care, tableware and food packaging sectors. To achieve these challenging objectives some molecules can be used in wet or solid coating formulations, e.g., cutin as a hydrophobic water-and grease-repellent coating, polysaccharides such as chitosan-chitin as an antimicrobial coating, and proteins as a gas barrier. This review collects the available knowledge on functional coatings with a focus on the raw materials used and methods of dispersion/application. It considers, in addition, the correlation with the desired final properties of the applied coatings, thus discussing their potential
Electrosprayed chitin nanofibril/electrospun polyhydroxyalkanoate fiber mesh as functional nonwoven for skin application
Polyhydroxyalkanoates (PHAs) are a family of bio-based polyesters that have found different biomedical applications. Chitin and lignin, byproducts of fishery and plant biomass, show antimicrobial and anti-inflammatory activity on the nanoscale. Due to their polarities, chitin nanofibril (CN) and nanolignin (NL) can be assembled into micro-complexes, which can be loaded with bioactive factors, such as the glycyrrhetinic acid (GA) and CN-NL/GA (CLA) complexes, and can be used to decorate polymer surfaces. This study aims to develop completely bio-based and bioactive meshes intended for wound healing. Poly(3-hydroxybutyrate)/ Poly(3-hydroxyoctanoate-co-3-hydroxydecanoate), P(3HB)/P(3HO-co-3HD) was used to produce films and fiber meshes, to be surface-modified via electrospraying of CN or CLA to reach a uniform distribution. P(3HB)/P(3HO-co-3HD) fibers with desirable size and morphology were successfully prepared and functionalized with CN and CLA using electrospinning and tested in vitro with human keratinocytes. The presence of CN and CLA improved the indirect antimicrobial and anti-inflammatory activity of the electrospun fiber meshes by downregulating the expression of the most important pro-inflammatory cytokines and upregulating human defensin 2 expression. This natural and eco-sustainable mesh is promising in wound healing applications
Tracking global changes induced in the CD4 T-cell receptor repertoire by immunization with a complex antigen using short stretches of CDR3 protein sequence.
The clonal theory of adaptive immunity proposes that immunological responses are encoded by increases in the frequency of lymphocytes carrying antigen-specific receptors. In this study, we measure the frequency of different T-cell receptors (TcR) in CD4 + T cell populations of mice immunized with a complex antigen, killed Mycobacterium tuberculosis, using high throughput parallel sequencing of the TcRβ chain. Our initial hypothesis that immunization would induce repertoire convergence proved to be incorrect, and therefore an alternative approach was developed that allows accurate stratification of TcR repertoires and provides novel insights into the nature of CD4 + T-cell receptor recognition
A Small Peptide Increases Drug Delivery in Human Melanoma Cells
Melanoma is the most fatal type of skin cancer and is notoriously resistant to chemotherapies. The response of melanoma to current treatments is difficult to predict. To combat these challenges, in this study, we utilize a small peptide to increase drug delivery to melanoma cells. A peptide library array was designed and screened using a peptide array-whole cell binding assay, which identified KK-11 as a novel human melanoma-targeting peptide. The peptide and its D-amino acid substituted analogue (VPWxEPAYQrFL or D-aa KK-11) were synthesized via a solid-phase strategy. Further studies using FITC-labeled KK-11 demonstrated dose-dependent uptake in human melanoma cells. D-aa KK-11 significantly increased the stability of the peptide, with 45.3% remaining detectable after 24 h with human serum incubation. Co-treatment of KK-11 with doxorubicin was found to significantly enhance the cytotoxicity of doxorubicin compared to doxorubicin alone, or sequential KK-11 and doxorubicin treatment. In vivo and ex vivo imaging revealed that D-aa KK-11 distributed to xenografted A375 melanoma tumors as early as 5 min and persisted up to 24 h post tail vein injection. When co-administered, D-aa KK-11 significantly enhanced the anti-tumor activity of a novel nNOS inhibitor (MAC-3-190) in an A375 human melanoma xenograft mouse model compared to MAC-3-190 treatment alone. No apparent systemic toxicities were observed. Taken together, these results suggest that KK-11 may be a promising human melanoma-targeted delivery vector for anti-melanoma cargo
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