Photonic Source of Heralded Greenberger-Horne-Zeilinger States.

Generating large multiphoton entangled states is of main interest due to enabling universal photonic quantum computing and all-optical quantum repeater nodes. These applications exploit measurement-based quantum computation using cluster states. Remarkably, it was shown that photonic cluster states of arbitrary size can be generated by using feasible heralded linear optics fusion gates that act on heralded three-photon Greenberger-Horne-Zeilinger (GHZ) states as the initial resource state. Thus, the capability of generating heralded GHZ states is of great importance for scaling up photonic quantum computing. Here, we experimentally demonstrate this required building block by reporting a polarisation-encoded heralded GHZ state of three photons, for which we build a high-rate six-photon source (547±2 Hz) from a solid-state quantum emitter and a stable polarization-based interferometer. The detection of three ancillary photons heralds the generation of three-photon GHZ states among the remaining particles with fidelities up to F=0.7278±0.0106. Our results initiate a path for scalable entangling operations using heralded linear-optics implementations.

[Utilization of video consultation in cardiovascular lipid treatment]. / Anwendung der Videosprechstunde in der kardiovaskulären Lipidbehandlung.

BACKGROUND: Video consultation is a possibility for physician-patient communication independent of the location; however, only limited information is available for the possibility of sole use since 2018. METHODS: After the implementation of video consultation (Viomedi) in lipid consultations at the Medical University Mainz, the patients in the first quarter of 2022 were assessed depending on the possibility, suitability and readiness to participate. Included were patients under lipid management and long COVID patients. After treatment an online survey was carried out on the utilization and appraisal. RESULTS: Of the 134 patients 29.1% were inclusively treated (3 refusals). All subjects (16 replies) reported having managed (very) well. Advantages were seen in counselling and follow-up. Problems were feared with respect to technology and possible disorders. Data protection aspects played a subordinate role. In comparison to telephone calls, a significant improvement in the physician-patient relationship (p-value = 0.00027), the quality of treatment and information (p-value both = 0.00044), the access to care (p-value = 0.0053) and the communication (p-value = 0.021) was assumed. An improvement in access to care (p-value = 0.021) and the quality of information (p-value = 0.034) was seen in comparison to personal contact. The main problems were a lack of experience, technical requirements, technical problems and unpunctuality of the practitioner. The flexibility, low effort and the pleasant consultation were all praised. All subjects wanted to use the video consultation again. CONCLUSION: Video consultation can represent a supplement to treatment of patients under lipid management. The correct use requires exact planning and further research.

The unique fibrilar to platy nano- and microstructure of twinned rotaliid foraminiferal shell calcite.

Diversification of biocrystal arrangements, incorporation of biopolymers at many scale levels and hierarchical architectures are keys for biomaterial optimization. The planktonic rotaliid foraminifer Pulleniatina obliquiloculata displays in its shell a new kind of mesocrystal architecture. Shell formation starts with crystallization of a rhizopodial network, the primary organic sheet (POS). On one side of the POS, crystals consist of blocky domains of 1 µm. On the other side of the POS crystals have dendritic-fractal morphologies, interdigitate and reach sizes of tens of micrometers. The dendritic-fractal crystals are twinned. At the site of nucleation, twinned crystals consist of minute fibrils. With distance away from the nucleation-site, fibrils evolve to bundles of crystallographically well co-oriented nanofibrils and to, twinned, platy-blade-shaped crystals that seam outer shell surfaces. The morphological nanofibril axis is the crystallographic c-axis, both are perpendicular to shell vault. The nanofibrillar calcite is polysynthetically twinned according to the 60°/[100] (= m/{001}) twin law. We demonstrate for the twinned, fractal-dendritic, crystals formation at high supersaturation and growth through crystal competition. We show also that c-axis-alignment is already induced by biopolymers of the POS and is not simply a consequence of growth competition. We discuss determinants that lead to rotaliid calcite formation.

Patterns of crystal organization and calcite twin formation in planktonic, rotaliid, foraminifera shells and spines.

The foraminiferal order Rotaliida represents one third of the extant genera of foraminifers. The shells of these organisms are extensively used to decipher characteristics of marine ecosystems and global climate events. It was shown that shell calcite of benthic Rotaliida is twinned. We extend our previous work on microstructure and texture characterization of benthic Rotaliida and investigate shell calcite organization for planktonic rotaliid species. Based on results gained from electron backscattered diffraction (EBSD) and field emission electron microscopy (FESEM) imaging of chemically etched/fixed shell surfaces we show for the planktonic species Globigerinoides sacculifer, Pulleniatina obliquiloculata, Orbulina universa (belonging to the two main planktonic, the globigerinid and globorotaliid, clades): very extensive 60°-{001}-twinning of the calcite and describe a new and specific microstructure for the twinned crystals. We address twin and crystal morphology development from nucleation within a biopolymer template (POS) to outermost shell surfaces. We demonstrate that the calcite of the investigated planktonic Rotaliida forms through competitive growth. We complement the structural knowledge gained on the clade 1 and clade 2 species with EBSD results of Globigerinita glutinata and Candeina nitida shells (clade 3 planktonic species). The latter are significantly less twinned and have a different shell calcite microstructure. We demonstrate that the calcite of all rotaliid species is twinned, however, to different degrees. We discuss for the species of the three planktonic clades characteristics of the twinned calcite and of other systematic misorientations. We address the strong functionalization of foraminiferal calcite and indicate how the twinning affects biocalcite material properties.

Experimental quantum speed-up in reinforcement learning agents.

As the field of artificial intelligence advances, the demand for algorithms that can learn quickly and efficiently increases. An important paradigm within artificial intelligence is reinforcement learning1, where decision-making entities called agents interact with environments and learn by updating their behaviour on the basis of the obtained feedback. The crucial question for practical applications is how fast agents learn2. Although various studies have made use of quantum mechanics to speed up the agent's decision-making process3,4, a reduction in learning time has not yet been demonstrated. Here we present a reinforcement learning experiment in which the learning process of an agent is sped up by using a quantum communication channel with the environment. We further show that combining this scenario with classical communication enables the evaluation of this improvement and allows optimal control of the learning progress. We implement this learning protocol on a compact and fully tunable integrated nanophotonic processor. The device interfaces with telecommunication-wavelength photons and features a fast active-feedback mechanism, demonstrating the agent's systematic quantum advantage in a setup that could readily be integrated within future large-scale quantum communication networks.

Complex Membrane Remodeling during Virion Assembly of the 30,000-Year-Old Mollivirus Sibericum.

Cellular membranes ensure functional compartmentalization by dynamic fusion-fission remodeling and are often targeted by viruses during entry, replication, assembly, and egress. Nucleocytoplasmic large DNA viruses (NCLDVs) can recruit host-derived open membrane precursors to form their inner viral membrane. Using complementary three-dimensional (3D)-electron microscopy techniques, including focused-ion beam scanning electron microscopy and electron tomography, we show that the giant Mollivirus sibericum utilizes the same strategy but also displays unique features. Indeed, assembly is specifically triggered by an open cisterna with a flat pole in its center and open curling ends that grow by recruitment of vesicles never reported for NCLDVs. These vesicles, abundant in the viral factory (VF), are initially closed but open once in close proximity to the open curling ends of the growing viral membrane. The flat pole appears to play a central role during the entire virus assembly process. While additional capsid layers are assembled from it, it also shapes the growing cisterna into immature crescent-like virions and is located opposite to the membrane elongation and closure sites, thereby providing virions with a polarity. In the VF, DNA-associated filaments are abundant, and DNA is packed within virions prior to particle closure. Altogether, our results highlight the complexity of the interaction between giant viruses and their host. Mollivirus assembly relies on the general strategy of vesicle recruitment, opening, and shaping by capsid layers similar to all NCLDVs studied until now. However, the specific features of its assembly suggest that the molecular mechanisms for cellular membrane remodeling and persistence are unique.IMPORTANCE Since the first giant virus Mimivirus was identified, other giant representatives are isolated regularly around the world and appear to be unique in several aspects. They belong to at least four viral families, and the ways they interact with their hosts remain poorly understood. We focused on Mollivirus sibericum, the sole representative of "Molliviridae," which was isolated from a 30,000-year-old permafrost sample and exhibits spherical virions of complex composition. In particular, we show that (i) assembly is initiated by a unique structure containing a flat pole positioned at the center of an open cisterna, (ii) core packing involves another cisterna-like element seemingly pushing core proteins into particles being assembled, and (iii) specific filamentous structures contain the viral genome before packaging. Altogether, our findings increase our understanding of how complex giant viruses interact with their host and provide the foundation for future studies to elucidate the molecular mechanisms of Mollivirus assembly.

Detection of herpesvirus capsids in transmission electron microscopy images using transfer learning.

The detailed analysis of secondary envelopment of the Human betaherpesvirus 5/human cytomegalovirus (HCMV) from transmission electron microscopy (TEM) images is an important step towards understanding the mechanisms underlying the formation of infectious virions. As a step towards a software-based quantification of different stages of HCMV virion morphogenesis in TEM, we developed a transfer learning approach based on convolutional neural networks (CNNs) that automatically detects HCMV nucleocapsids in TEM images. In contrast to existing image analysis techniques that require time-consuming manual definition of structural features, our method automatically learns discriminative features from raw images without the need for extensive pre-processing. For this a constantly growing TEM image database of HCMV infected cells was available which is unique regarding image quality and size in the terms of virological EM. From the two investigated types of transfer learning approaches, namely feature extraction and fine-tuning, the latter enabled us to successfully detect HCMV nucleocapsids in TEM images. Our detection method has outperformed some of the existing image analysis methods based on discriminative textural indicators and radial density profiles for virus detection in TEM images. In summary, we could show that the method of transfer learning can be used for an automated detection of viral capsids in TEM images with high specificity using standard computers. This method is highly adaptable and in future could be easily extended to automatically detect and classify virions of other viruses and even distinguish different virion maturation stages.

FIB and MIP: understanding nanoscale porosity in molecularly imprinted polymers via 3D FIB/SEM tomography.

We present combined focused ion beam/scanning electron beam (FIB/SEM) tomography as innovative method for differentiating and visualizing the distribution and connectivity of pores within molecularly imprinted polymers (MIPs) and non-imprinted control polymers (NIPs). FIB/SEM tomography is used in cell biology for elucidating three-dimensional structures such as organelles, but has not yet been extensively applied for visualizing the heterogeneity of nanoscopic pore networks, interconnectivity, and tortuosity in polymers. To our best knowledge, the present study is the first application of this strategy for analyzing the nanoscale porosity of MIPs. MIPs imprinted for propranolol - and the corresponding NIPs - were investigated establishing FIB/SEM tomography as a viable future strategy complementing conventional isotherm studies. For visualizing and understanding the properties of pore networks in detail, polymer particles were stained with osmium tetroxide (OsO4) vapor, and embedded in epoxy resin. Staining with OsO4 provides excellent contrast during high-resolution SEM imaging. After optimizing the threshold to discriminate between the stained polymer matrix, and pores filled with epoxy resin, a 3D model of the sampled volume may be established for deriving not only the pore volume and pore surface area, but also to visualize the interconnectivity and tortuosity of the pores within the sampled polymer volume. Detailed studies using different types of cross-linkers and the effect of hydrolysis on the resulting polymer properties have been investigated. In comparison of MIP and NIP, it could be unambiguously shown that the interconnectivity of the visualized pores in MIPs is significantly higher vs. the non-imprinted polymer, and that the pore volume and pore area is 34% and approx. 35% higher within the MIP matrix. This confirms that the templating process not only induces selective binding sites, but indeed also affects the physical properties of such polymers down to the nanoscale, and that additional chemical modification, e.g., via hydrolysis clearly affects that nature of the polymer.

Optimizing Surveillance for South American Origin Influenza A Viruses Along the United States Gulf Coast Through Genomic Characterization of Isolates from Blue-winged Teal (Anas discors).

Relative to research focused on inter-continental viral exchange between Eurasia and North America, less attention has been directed towards understanding the redistribution of influenza A viruses (IAVs) by wild birds between North America and South America. In this study, we genomically characterized 45 viruses isolated from blue-winged teal (Anas discors) along the Texas and Louisiana Gulf Coast during March of 2012 and 2013, coincident with northward migration of this species from Neotropical wintering areas to breeding grounds in the United States and Canada. No evidence of South American lineage genes was detected in IAVs isolated from blue-winged teal supporting restricted viral gene flow between the United States and southern South America. However, it is plausible that blue-winged teal redistribute IAVs between North American breeding grounds and wintering areas throughout the Neotropics, including northern South America, and that viral gene flow is limited by geographical barriers further south (e.g., the Amazon Basin). Surveillance for the introduction of IAVs from Central America and northern South America into the United States may be further optimized through genomic characterization of viruses resulting from coordinated, concurrent sampling efforts targeting blue-winged teal and sympatric species throughout the Neotropics and along the United States Gulf Coast.

Preservation of protein fluorescence in embedded human dendritic cells for targeted 3D light and electron microscopy.

In this study, we present a correlative microscopy workflow to combine detailed 3D fluorescence light microscopy data with ultrastructural information gained by 3D focused ion beam assisted scanning electron microscopy. The workflow is based on an optimized high pressure freezing/freeze substitution protocol that preserves good ultrastructural detail along with retaining the fluorescence signal in the resin embedded specimens. Consequently, cellular structures of interest can readily be identified and imaged by state of the art 3D confocal fluorescence microscopy and are precisely referenced with respect to an imprinted coordinate system on the surface of the resin block. This allows precise guidance of the focused ion beam assisted scanning electron microscopy and limits the volume to be imaged to the structure of interest. This, in turn, minimizes the total acquisition time necessary to conduct the time consuming ultrastructural scanning electron microscope imaging while eliminating the risk to miss parts of the target structure. We illustrate the value of this workflow for targeting virus compartments, which are formed in HIV-pulsed mature human dendritic cells.

Electron tomography and cryo-SEM characterization reveals novel ultrastructural features of host-parasite interaction during Chlamydia abortus infection.

Chlamydia (C.) abortus is a widely spread pathogen among ruminants that can be transmitted to women during pregnancy leading to severe systemic infection with consecutive abortion. As a member of the Chlamydiaceae, C. abortus shares the characteristic feature of an obligate intracellular biphasic developmental cycle with two morphological forms including elementary bodies (EBs) and reticulate bodies (RBs). In contrast to other chlamydial species, C. abortus ultrastructure has not been investigated yet. To do so, samples were fixed by high-pressure freezing and processed by different electron microscopic methods. Freeze-substituted samples were analysed by transmission electron microscopy, scanning transmission electron microscopical tomography and immuno-electron microscopy, and freeze-fractured samples were analysed by cryo-scanning electron microscopy. Here, we present three ultrastructural features of C. abortus that have not been reported up to now. Firstly, the morphological evidence that C. abortus is equipped with the type three secretion system. Secondly, the accumulation and even coating of whole inclusion bodies by membrane complexes consisting of multiple closely adjacent membranes which seems to be a C. abortus specific feature. Thirdly, the formation of small vesicles in the periplasmic space of RBs in the second half of the developmental cycle. Concerning the time point of their formation and the fact that they harbour chlamydial components, these vesicles might be morphological correlates of an intermediate step during the process of redifferentiation of RBs into EBs. As this feature has also been shown for C. trachomatis and C. pneumoniae, it might be a common characteristic of the family of Chlamydiaceae.

CX3CR1⁺ cells facilitate the activation of CD4 T cells in the colonic lamina propria during antigen-driven colitis.

Dendritic cells (DCs) and macrophages populate the intestinal lamina propria to initiate immune responses required for the maintenance of intestinal homeostasis. To investigate whether CX3CR1(+) phagocytes communicate with CD4 T cells during the development of transfer colitis, we established an antigen-driven colitis model induced by the adoptive transfer of DsRed OT-II cells in CX3CR1(GFP/+) × RAG(-/-) recipients challenged with Escherichia coli expressing ovalbumin (OVA) fused to a cyan fluorescent protein (CFP). After colonization of CX3CR1(GFP/+) × RAG(-/-) animals with red fluorescent E. coli pCherry-OVA, colonic CX3CR1(+) cells but not CD103(+) DCs phagocytosed E. coli pCherry-OVA. Degraded bacterial-derived antigens are transported by CD103(+) DCs to mesenteric lymph nodes (MLNs), where CD103(+) DCs prime naive T cells. In RAG(-/-) recipients reconstituted with OT II cells and gavaged with OVA-expressing E. coli, colonic CX3CR1(+) phagocytes are in close contact with CD4 T cells and presented bacterial-derived antigens to CD4 T cells to activate and expand effector T cells.

Criteria impacting the cellular uptake of nanoparticles: a study emphasizing polymer type and surfactant effects.

A detailed understanding of the particle-cell interaction is essential and of immense interest in order to create a "specific carrier" for each particular application. In this paper, the effect of the surfactant type (non-ionic vs ionic) and polymer nature on the cellular uptake of fluorescent polystyrene and poly(L-lactide) nanoparticles was studied on HeLa cells. Nanoparticles in a size range from 100 to 160 nm were synthesized by the miniemulsion process. The particles were detected in cells by confocal laser scanning fluorescence microscopy and flow cytometry. It was found that the influence of the surface charge is greater than that of the polymer type itself. In fact, particles stabilized with cationic surfactant were incorporated in a large number irrespective of polymer type. Cellular pathways at ultrastructural level were studied by transmission electron microscopy in more detail to shed light on the particle-cell interaction based on the material properties. The criteria governing the cellular uptake of nanoparticles based on the polymer and surfactant types are finally established.

Three-dimensional analysis of intermediate filament networks using SEM tomography.

We identified tomographic reconstruction of a scanning electron microscopy tilt series recording the secondary electron signal as a well-suited method to generate high-contrast three-dimensional data of intermediate filament (IF) networks in pancreatic cancer cells. Although the tilt series does not strictly conform to the projection requirement of tomographic reconstruction, this approach is possible due to specific properties of the detergent-extracted samples. We introduce an algorithm to extract the graph structure of the IF networks from the tomograms based on image analysis tools. This allows a high-resolution analysis of network morphology, which is known to control the mechanical response of the cells to large-scale deformations. Statistical analysis of the extracted network graphs is used to investigate principles of structural network organization which can be linked to the regulation of cell elasticity.

Recovery of mechano-electrical transduction in rat cochlear hair bundles after postnatal destruction of the stereociliar cross-links.

Mechano-electrical transduction (MET) in the stereocilia of outer hair cells (OHCs) was studied in newborn Wistar rats using scanning electron microscopy to investigate the stereociliar cross-links, Nomarski laser differential interferometry to investigate stereociliar stiffness and by testing the functionality of the MET channels by recording the entry of fluorescent dye, FM1-43, into stereocilia. Preparations were taken from rats on their day of birth (P0) or 1-4 days later (P1-P4). Hair bundles developed from the base to the apex and from the inner to outer OHC rows. MET channel responses were detected in apical coil OHCs on P1. To study the possible recovery of MET after disrupting the cross-links, the same investigations were performed after the application of Ca(2+) chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) and allowing the treated samples to recover in culture medium for 0-20 h. We found that the structure and function were abolished by BAPTA. In P0-P1 samples, structural recovery was complete and the open probability of MET channels reached control values. In P3-P4 samples, complete recovery only occurred in OHCs of the outermost row. Although our results demonstrate an enormous recovery potential of OHCs in the postnatal period, the structural component restricts the potential for therapy in patients.

Comparison of different methods for thin section EM analysis of Mycobacterium smegmatis.

Bacteria are generally difficult specimens to prepare for conventional resin section electron microscopy and mycobacteria, with their thick and complex cell envelope layers being especially prone to artefacts. Here we made a systematic comparison of different methods for preparing Mycobacterium smegmatis for thin section electron microscopy analysis. These methods were: (1) conventional preparation by fixatives and epoxy resins at ambient temperature. (2) Tokuyasu cryo-section of chemically fixed bacteria. (3) rapid freezing followed by freeze substitution and embedding in epoxy resin at room temperature or (4) combined with Lowicryl HM20 embedding and ultraviolet (UV) polymerization at low temperature and (5) CEMOVIS, or cryo electron microscopy of vitreous sections. The best preservation of bacteria was obtained with the cryo electron microscopy of vitreous sections method, as expected, especially with respect to the preservation of the cell envelope and lipid bodies. By comparison with cryo electron microscopy of vitreous sections both the conventional and Tokuyasu methods produced different, undesirable artefacts. The two different types of freeze-substitution protocols showed variable preservation of the cell envelope but gave acceptable preservation of the cytoplasm, but not lipid bodies, and bacterial DNA. In conclusion although cryo electron microscopy of vitreous sections must be considered the 'gold standard' among sectioning methods for electron microscopy, because it avoids solvents and stains, the use of optimally prepared freeze substitution also offers some advantages for ultrastructural analysis of bacteria.

Experimental realization of Dicke states of up to six qubits for multiparty quantum networking.

We report the first experimental generation and characterization of a six-photon Dicke state. The produced state shows a fidelity of F=0.56+/-0.02 with respect to an ideal Dicke state and violates a witness detecting genuine six-qubit entanglement by 4 standard deviations. We confirm characteristic Dicke properties of our resource and demonstrate its versatility by projecting out four- and five-photon Dicke states, as well as four-photon Greenberger-Horne-Zeilinger and W states. We also show that Dicke states have interesting applications in multiparty quantum networking protocols such as open-destination teleportation, telecloning, and quantum secret sharing.

Use of high-pressure freeze fixation and freeze fracture electron microscopy to study the influence of the phospholipid molar ratio in the morphology and alignment of bicelles.

The high-pressure freeze fixation and freeze fracture electron microscopy techniques were combined with the (31)P nuclear magnetic resonance to study the morphological transitions of two different dimyristoyl-phosphatidilcholine/dihexanoyl-phosphocholine aggregates by the effect of temperature. Through these techniques, the relationship between magnetic alignment and the morphology of alignable and non-alignable aggregates was evaluated. The micrographs related to the non-alignable dimyristoyl-phosphatidilcholine/dihexanoyl-phosphocholine sample presented rounded objects at a temperature below the dimyristoyl-phosphatidilcholine phase transition (T(m)) and, above this temperature an increase of viscosity was followed by the appearance of large elongated aggregates. The micrographs related to the alignable dimyristoyl-phosphatidilcholine/dihexanoyl-phosphocholine sample presented discoidal objects below T(m). Above T(m), when the best alignment was achieved, the images showed large areas of lamellar stacked bilayers and the presence of some multilamellar vesicles. Our results reveal that the composition of the aggregates is a key factor determining the morphological transitions of the bicellar systems. Understanding of the rules governing these transitions is crucial to modulate characteristics of these systems and to adequate them for different applications.

High-resolution cryo-SEM allows direct identification of F-actin at the inner nuclear membrane of Xenopus oocytes by virtue of its structural features.

The nuclear envelope of Xenopus laevis stage VI oocytes was studied in a high-resolution field emission cryo-scanning electron microscope to compare the level of structural preservation obtainable by different procedures of specimen preparation. All approaches generally allowed frequent detection of long filaments of about 10 nm in diameter that were attached to the nuclear envelope's inner membrane facing the nuclear interior. Structural details of these 10-nm filaments, however, could not be unveiled by standard procedures of specimen preparation and analysis, including critical point drying and imaging at room temperature. In contrast, after freeze-drying and imaging at -100 degrees C, the 10-nm filament type was found to be composed of distinct globular subunits of approximately 5 nm in diameter that were arranged in a helical manner with right-handed periodicity. Stereoscopic images showed that some of these filaments were lying directly on the membrane whereas others appeared to hover at a certain distance above the nuclear envelope. The appearance of these filaments was highly similar to that of in vitro polymerized F-actin analysed in parallel, and closely resembled the structural characteristics of F-actin filaments described earlier. By virtue of their structural features we therefore conclude that these filaments at the nuclear periphery represent F-actin. The high level of structural resolution obtainable by field emission cryo-SEM illustrates the potential of this method for studying details of biological structures in a subcellular context.

Penetration and growth of DPPC/DHPC bicelles inside the stratum corneum of the skin.

The effect of dipalmitoyl phosphatidylcholine (DPPC)/dihexanoyl phosphatidylcholine (DHPC) bicelles on the microstructure of pig stratum corneum (SC) in vitro was evaluated. The physicochemical characterization of these nanoaggregates revealed small disks with diameters around 15 nm and a thickness of 5.4 nm. Upon dilution, the bicelles grow and transform into vesicles. Cryogenic scanning electron microscopy (cryo-SEM) images of the SC pieces treated with this system showed vesicles of about 200 nm and lamellar-like structures in the intercellular lipid areas. These vesicles probably resulted from the growth and molecular rearrangement of the DPPC/DHPC bicelles after penetrating the SC. The presence of lamellar-like structures is ascribed to the interaction of the lipids from bicelles with the SC lipids. The bicellar system used is suitable to penetrate the skin SC and to reinforce the intercellular lipid areas, constituting a promising tool for skin applications.