Search

Polarization images offer crucial functionalities across multiple scientific domains, providing access to physical information beyond conventional measures such as intensity, phase, and spectrum of light. However, the challenge of transmitting polarization images through complex media has restricted their application in optical communication and imaging. Here, a novel approach utilizing deep learning for the transmission of full‐Stokes polarization images through scattering media is presented. It is demonstrated that any input polarization image can be reconstructed in a single shot by employing only an intensity sensor. By supervised training of a deep neural network, high‐accuracy full‐Stokes reconstruction is achieved from the speckle pattern detected by an intensity camera. Leveraging the deep learning based polarization decoder, a polarization‐colored encoding scheme is devised to enable increased‐capacity data transmission through disordered channels. Fast, wavelength‐independent, on‐chip, polarization imaging in complex media enables the utilization of polarization‐structured light in multimode fibres and opaque materials, unlocking new possibilities in optical communication, cryptography, and quantum technology. [ABSTRACT FROM AUTHOR]

Coherent random lasers (RLs) originate from the resonant amplification of the light scattered by disordered media resulting in spiky emission spectra with well‐defined spectral signatures. Here coherent RL emission is proposed as a tool for identifying the spectral fingerprint of porous micro‐structured materials obtained by soft lithography techniques. The close control of the spatial patterns and structural characteristics of the scattering elements enable us to obtain stable and unique RL spectra distinctive of each lithographed device. The spectral emission has been thoroughly analyzed with respect to the morphology of the devices in terms of surface roughness and surface volume fraction, demonstrating that the packing of the scattering particles is the main factor in determining a RL emission characterized by multiple linewidths with a high level of coherence. The findings provide novel insights for the realization of miniaturized photonic devices with selectable optical features. [ABSTRACT FROM AUTHOR]

Spin and orbital angular momenta of light are important degrees of freedom in nanophotonics which control light propagation, optical forces, and information encoding. Here, it is shown that graphene‐supported plasmonic nanostructures with broken rotational symmetry provide a surprising spin to orbital angular momentum conversion, which can be continuously controlled by changing the electrochemical potential of graphene. Upon resonant illumination by a circularly polarized plane wave, a polygonal array of indium‐tin‐oxide nanoparticles on a graphene sheet generates the scattered field carrying electrically‐tunable orbital angular momentum. This unique photonic spin‐orbit interaction occurs due to the strong coupling between graphene plasmon polaritons and localized surface plasmons of the nanoparticles and leads to the controlled directional excitation of graphene plasmons. The tuneable spin‐orbit conversion paves the way for high‐rate information encoding in optical communications, electric steering functionalities in optical tweezers, and nanorouting of higher‐dimensional entangled photon states. [ABSTRACT FROM AUTHOR]

Psoriasis (PS) and atopic dermatitis (AD) are common inflammatory skin diseases characterized by an imbalance in specific T‐cell subsets, resulting in a specific cytokine profile in patients. Obtaining models closely resembling both pathologies along with a relevant clinical impact is crucial for the development of new therapies because of the high prevalence of these diseases. Single‐gene mouse models developed until now do not fully reflect the complexity of these disorders, in part not only because of inherent differences between mice and humans but also because of the multifactorial nature of these pathologies. The skin‐humanized mouse model developed by our group, based on a tissue engineering approach, has been used to test therapeutic strategies, although this methodology is still technically challenging and not widely available. The skin‐humanized mouse models for PS and AD reproduce human skin phenotypes, providing valuable tools for drug development and testing in the preclinical setting. The tissue engineering approach allows the development of personalized medicine, covering the broad genotypic spectrum of these pathologies. This review highlights the main differences between available murine models focusing on the tissue‐specific immunity of PS and AD. We discuss their contribution to unravel the complex pathophysiology of these diseases and to translate this knowledge into more accurate therapies. [ABSTRACT FROM AUTHOR]

Multiple scattering of electromagnetic (EM) waves arises in disordered media with a refractive index varying on the scale of the wavelength. The diffusion approximation is a powerful tool to treat multiple scattering as a photon random walk, neglecting resonant phenomena. However, as the light intensity varies on a scale much smaller than the transport mean free path, resonances may occur in media formed by finite‐size scatterers and break the diffusion approximation. The energy and phase velocity are very useful tools to reveal the onset of the resonant transport regime. In this paper the study of the propagation of terahertz (THz) waves through 3D random media by employing terahertz time‐domain spectroscopy (THz‐TDS) is addressed. Specifically, measurements of the electric field transmitted by samples of different thicknesses made of 1 mm diameter silica spheres dispersed in a paraffin matrix at different filling fractions are reported. This investigation has provided an accurate measurement of the EM field phase and, hence, information on the radiation propagation velocity that has enabled the first observation of a photonic glass at the THz range. [ABSTRACT FROM AUTHOR]

The description of irreversible phenomena is a still debated topic in quantum mechanics. Still nowadays, there is no clear procedure to distinguish the coupling with external baths from the intrinsic irreversibility in isolated systems. In 1928 Gamow introduced states with exponentially decaying observables not belonging to the conventional Hilbert space. These states are named Gamow vectors, and they belong to rigged Hilbert spaces. This review summarizes the contemporary approach using Gamow vectors and rigged Hilbert space formalism as foundations of a generalized 'time asymmetric' quantum mechanics. We study the irreversible propagation of specific wave packets and show that the topic is surprisingly related to the problem of irreversibility of shock waves in classical nonlinear evolution. We specifically consider the applications in the field of nonlinear optics. We show that it is possible to emulate irreversible quantum mechanical process by the nonlinear evolution of a laser beam and we provide experimental tests by the generation of dispersive shock waves in highly nonlocal regimes. We demonstrate experimentally the quantization of decay rates predicted by the time-asymmetric quantum mechanics. This work furnishes support to the idea of intrinsically irreversible wave propagation, and to novel tests of the foundations of quantum mechanics. [ABSTRACT FROM AUTHOR]

Epidermolysis bullosa with pyloric atresia ( EB- PA) is a rare autosomal recessive hereditary disease with a variable prognosis from lethal to very mild. EB- PA is classified into Simplex form ( EBS- PA: OMIM #612138) and Junctional form ( JEB- PA: OMIM #226730), and it is caused by mutations in ITGA6, ITGB4 and PLEC genes. We report the analysis of six patients with EB- PA, including two dizygotic twins. Skin immunofluorescence epitope mapping was performed followed by PCR and direct sequencing of the ITGB4 gene. Two of the patients presented with non-lethal EB- PA associated with missense ITGB4 gene mutations. For the other four, early postnatal demise was associated with complete lack of β4 integrin due to a variety of ITGB4 novel mutations (2 large deletions, 1 splice-site mutation and 3 missense mutations). One of the deletions spanned 278 bp, being one of the largest reported to date for this gene. Remarkably, we also found for the first time a founder effect for one novel mutation in the ITGB4 gene. We have identified 6 novel mutations in the ITGB4 gene to be added to the mutation database. Our results reveal genotype-phenotype correlations that contribute to the molecular understanding of this heterogeneous disease, a pivotal issue for prognosis and for the development of novel evidence-based therapeutic options for EB management. [ABSTRACT FROM AUTHOR]

The random laser emission from the functionalized thienyl-S,S-dioxide quinquethiophene (T5OCx) in confined patterns with different shapes is demonstrated. Functional patterning of the light emitter organic material in well defined features is obtained by spontaneous molecular self-assembly guided by surface tension driven (STD) lithography. Such controlled supramolecular nano-aggregates act as scattering centers allowing the fabrication of one-component organic lasers with no external resonator and with desired shape and efficiency. Atomic force microscopy shows that different geometric pattern with different supramolecular organization obtained by the lithographic process tailors the coherent emission properties by controlling the distribution and the size of the random scatterers. [ABSTRACT FROM AUTHOR]

Cutaneous diabetic wounds greatly affect the quality of life of patients, causing a substantial economic impact on the healthcare system. The limited clinical success of conventional treatments is mainly attributed to the lack of knowledge of the pathogenic mechanisms related to chronic ulceration. Therefore, management of diabetic ulcers remains a challenging clinical issue. Within this context, reliable animal models that recapitulate situations of impaired wound healing have become essential. In this study, we established a new in vivo humanised model of delayed wound healing in a diabetic context that reproduces the main features of the human disease. Diabetes was induced by multiple low doses of streptozotocin in bioengineered human-skin-engrafted immunodeficient mice. The significant delay in wound closure exhibited in diabetic wounds was mainly attributed to alterations in the granulation tissue formation and resolution, involving defects in wound bed maturation, vascularisation, inflammatory response and collagen deposition. In the new model, a cell-based wound therapy consisting of the application of plasma-derived fibrin dermal scaffolds containing fibroblasts consistently improved the healing response by triggering granulation tissue maturation and further providing a suitable matrix for migrating keratinocytes during wound re-epithelialisation. The present preclinical wound healing model was able to shed light on the biological processes responsible for the improvement achieved, and these findings can be extended for designing new therapeutic approaches with clinical relevance. [ABSTRACT FROM AUTHOR]

Strains of mice vary in their susceptibility to ultra-violet (UV) radiation-induced skin tumors. Some strains of hairless mice (homozygous for the spontaneous Hr hr mutation) are particularly susceptible to these tumors. The skin tumors that develop in hairless mice resemble, both at the morphologic and molecular levels, UV-induced squamous cell carcinomas (SCC) and their precursors in human. The most commonly employed hairless mice belong to the SKH1 stock. However, these mice are outbred and their genetic background is not characterized, which makes them a poor model for genetic studies. We have developed a new inbred strain from outbred SKH1 mice that we named SKHIN/Sprd (now at generation F31). In order to characterize the genetic background of this new strain, we genotyped a cohort of mice at F30 with 92 microsatellites and 140 single nucleotide polymorphisms (SNP) evenly distributed throughout the mouse genome. We also exposed SKHIN/Sprd mice to chronic UV irradiation and showed that they are as susceptible to UV-induced skin carcinogenesis as outbred SKH1 mice. In addition, we proved that, albeit with low efficiency, inbred SKHIN/Sprd mice are suitable for transgenic production by classical pronuclear microinjection. This new inbred strain will be useful for the development of transgenic and congenic strains on a hairless inbred background as well as the establishment of syngeneic tumor cell lines. These new tools can potentially help elucidate a number of features of the cutaneous response to UV irradiation in humans, including the effect of genetic background and modifier genes. [ABSTRACT FROM AUTHOR]

Recessive dystrophic epidermolysis bullosa ( RDEB) is caused by deficiency of type VII collagen due to COL7A1 mutations such as c.6527insC, recurrently found in the Spanish RDEB population. Assessment of clonal correction-based therapeutic approaches for RDEB requires large expansions of cells, exceeding the replication capacity of human primary keratinocytes. Thus, immortalized RDEB cells with enhanced proliferative abilities would be valuable. Using either the SV40 large T antigen or papillomavirus HPV16-derived E6-E7 proteins, we immortalized and cloned RDEB keratinocytes carrying the c.6527insC mutation. Clones exhibited high proliferative and colony-forming features. Cytogenetic analysis revealed important differences between T antigen-driven and E6- E7-driven immortalization. Immortalized cells responded to differentiation stimuli and were competent for epidermal regeneration and recapitulation of the blistering RDEB phenotype in vivo. These features make these cell lines useful to test novel therapeutic approaches including those aimed at editing mutant COL7A1. [ABSTRACT FROM AUTHOR]

Discusses the findings of a study which assessed the effects of human epidermal keratin 8 (HK8) aberant expression in normal and transformed skin. Expression of HK8 transgene in mouse epidermis; Alteration of terminal differentiation in transgenic mouse epidermis; Differences between the epidermal hyperplasia and dysplastic hair follicles of TGHK8 transgenic mice.

Random media with tailored optical properties are attracting burgeoning interest for applications in imaging, biophysics, energy, nanomedicine, spectroscopy, cryptography, and telecommunications. A key paradigm for devices based on this class of materials is the transmission matrix, the tensorial link between the input and the output signals, that describes in full their optical behavior. The transmission matrix has specific statistical properties, such as the existence of lossless channels, that can be used to transmit information, and are determined by the disorder distribution. In nonlinear materials, these channels may be modulated and the transmission matrix tuned accordingly. Here, the direct measurement of the nonlinear transmission matrix of complex materials is reported, exploiting the strong optothermal nonlinearity of scattering silica aerogel (SA). It is shown that the dephasing effects due to nonlinearity are both controllable and reversible, opening the road to applications based on the nonlinear response of random media. [ABSTRACT FROM AUTHOR]

A novel theoretical framework is developed describing polariton‐enhanced spin–orbit interaction (SOI) of light on the surface of 2D media. The reduced dimensionality of the system is exploited to introduce a quantum‐like formalism particularly suitable to fully take advantage of rotational invariance. Conservation of total angular momentum upon scattering enables the physical unveiling of the interaction between radiation and the 2D material along with the detailed exchange processes among orbital and spin components. In addition, the formalism is specialized to doped extended graphene, finding such an SOI to be dramatically enhanced by the excitation of plasmons propagating radially along the graphene sheet. Several examples of the enormous possibilities offered by plasmon‐enhanced SOI of light are provided including vortex generation, mixing, and engineering of tunable deep subwavelength arrays of optical traps in the near field. 2D materials provide a peculiar mechanism of spin–orbit interaction of light which is enhanced by surface polariton excitation. Conservation of the total angular momentum upon light scattering from a 2D material is exploited to unveil the mechanism and identify the detailed exchange processes among orbital and spin components. Several near‐field applications are provided including vortex generation, mixing, and engineering of tunable deep subwavelength arrays. [ABSTRACT FROM AUTHOR]

The author discusses the association of 7,12-Dimethylbenzanthracene-(DMBA)induced Ha-ras-ment oncogene mutation with tumor initiation. Topics discussed include both papillomas and carcinomas had transforming Ha-ras activity, mutation in the Harvey ras (Ha-ras) gene resulting in DMBA initiation and evidences for amplification of the mutant Ha-ras at later stages of carcinogenesis.