A hierarchical Bilayered scaffold for periodontal complex structure regeneration.

The periodontal tissue comprises alveolar bone, cementum, and periodontal ligament (PDL), forming a highly hierarchical architecture. Although current therapies could regenerate the hard tissue well, the simultaneous reconstruction of hard and soft tissue remains a great clinical challenge with the major difficulty in highly orientated PDL regeneration. Using the unidirectional freeze-casting method and biomimetic mineralization technique, we construct a hierarchical bilayer scaffold with the aligned chitosan scaffold with ZIF-8 resembling PDL, and intrafibrillarly mineralized collagen resembling alveolar bone. The hierarchical bilayer scaffold exhibits different geomorphic clues and chemical microenvironments to realize a perfect simulation of the natural periodontal hierarchical architecture. The aligned scaffold with ZIF-8 could induce the fibrogenic differentiation of bone mesenchymal stromal cells (BMSCs), and the mineralized scaffold could induce osteogenic differentiation of BMSCs. The hierarchical bilayer scaffold could simulate periodontal complex tissue, exhibiting great promise for synchronized multi-tissue regeneration of periodontal tissue.

De Novo Missense Variations of ATP8B2 Impair Its Phosphatidylcholine Flippase Activity.

P4-ATPases comprise a family of lipid flippases that translocate lipids from the exoplasmic (or luminal) to the cytoplasmic leaflet of biological membranes. Of the 14 known human P4-ATPases, ATP8B2 is a phosphatidylcholine flippase at the plasma membrane, but its physiological function is not well understood. Although ATP8B2 could interact with both CDC50A and CDC50B, it required only the CDC50A interaction for its exit from the endoplasmic reticulum and subsequent transport to the plasma membrane. Three de novo monoallelic missense variations of ATP8B2 were found in patients with intellectual disability. None of these variations affected the interaction of ATP8B2 with CDC50A or its localization to the plasma membrane. However, variations of either of two amino acid residues, which are conserved in all P4-ATPases, significantly reduced the phosphatidylcholine flippase activity of ATP8B2. Furthermore, mutations in the corresponding residues of ATP8B1 and ATP11C were found to decrease their flippase activities toward phosphatidylcholine and phosphatidylserine, respectively. These results indicate that the conserved amino acid residues are crucial for the enzymatic activities of the P4-ATPases.

Ultrasteep Slope Cryogenic FETs Based on Bilayer Graphene.

Cryogenic field-effect transistors (FETs) offer great potential for applications, the most notable example being classical control electronics for quantum information processors. For the latter, on-chip FETs with low power consumption are crucial. This requires operating voltages in the millivolt range, which are only achievable in devices with ultrasteep subthreshold slopes. However, in conventional cryogenic metal-oxide-semiconductor (MOS)FETs based on bulk material, the experimentally achieved inverse subthreshold slopes saturate around a few mV/dec due to disorder and charged defects at the MOS interface. FETs based on two-dimensional materials offer a promising alternative. Here, we show that FETs based on Bernal stacked bilayer graphene encapsulated in hexagonal boron nitride and graphite gates exhibit inverse subthreshold slopes of down to 250 µV/dec at 0.1 K, approaching the Boltzmann limit. This result indicates an effective suppression of band tailing in van der Waals heterostructures without bulk interfaces, leading to superior device performance at cryogenic temperature.

Orchestrated Movement Sequences and Shape-Memory-like Effects in Pine Cones.

Hygroscopic seed-scale movement is responsible for the weather-adaptive opening and closing of pine cones and for facilitating seed dispersal under favorable environmental conditions. Although this phenomenon has long been investigated, many involved processes are still not fully understood. To gain a deeper mechanical and structural understanding of the cone and its functional units, namely the individual seed scales, we have investigated their desiccation- and wetting-induced movement processes in a series of analyses and manipulative experiments. We found, for example, that the abaxial scale surface is responsible for the evaporation of water from the closed cone and subsequent cone opening. Furthermore, we tested the capability of dry and deformed scales to restore their original shape and biomechanical properties by wetting. These results shed new light on the orchestration of scale movement in cones and the involved forces and provide information about the functional robustness and resilience of cones, leading to a better understanding of the mechanisms behind hygroscopic pine cone opening, the respective ecological framework, and, possibly, to the development of smart biomimetic actuators.

Strong interlayer magnetic exchange coupling in La3Ni2O7-δ revealed by inelastic neutron scattering.

After several decades of studies of high-temperature superconductivity, there is no compelling theory for the mechanism yet; however, the spin fluctuations have been widely believed to play a crucial role in forming the superconducting Cooper pairs. The recent discovery of high-temperature superconductivity near 80 K in the bilayer nickelate La3Ni2O7 under pressure provides a new platform to elucidate the origins of high-temperature superconductivity. We perform elastic and inelastic neutron scattering studies on a polycrystalline sample of La3Ni2O7-δ at ambient pressure. No magnetic order can be identified down to 10 K. The absence of long-range magnetic order in neutron diffraction measurements may be ascribed to the smallness of the magnetic moment. However, we observe a weak flat spin-fluctuation signal in the inelastic scattering spectra at ∼ 45 meV. The observed spin excitations could be interpreted as a result of strong interlayer and weak intralayer magnetic couplings for stripe-type antiferromagnetic orders. Our results provide crucial information on the spin dynamics and are thus important for understanding the superconductivity in La3Ni2O7.

Modulation of Kondo Behavior in a Two-Dimensional Epitaxial Bilayer Bi(111)/Fe3GeTe2 Moiré Heterostructure.

Artificial two-dimensional (2D) moiré superlattices provide a platform for generating exotic quantum matter or phenomena. Here, an epitaxial heterostructure composed of bilayer Bi(111) and an Fe3GeTe2 substrate with a zero-twist angle is acquired by molecular beam epitaxy. Scanning tunneling microscopy and spectroscopy studies reveal the spatially tailored Kondo resonance and interfacial magnetism within this moiré superlattice. Combined with first-principles calculations, it is found that the modulation effect of the moiré superlattice originates from the interfacial orbital hybridization between Bi and Fe atoms. Our work provides a tunable platform for strong electron correlation studies to explore 2D artificial heavy Fermion systems and interface magnetism.

Comparative Evaluation of the Survival Rates of Atraumatic Restorative Treatment Restorations Using Bilayer Technique along with Nanofilled Coating in Primary Molars: A Clinical Study.

Objective: To enhance the survival rate of atraumatic restorative treatment (ART) restorations using (class I and class II) bilayer technique of placing glass ionomer cement (GIC) along with nanofilled coating (NC) over the restorations, thereby improving longevity. Study design: A total of 178 primary molars in 67 children were selected and randomly divided into four groups. Group IA was treated with a single layer of GIC, followed by a protective layer of petroleum jelly in class I restoration. Group IB was treated with a single layer of GIC, followed by a protective layer of petroleum jelly in class II restoration. Group IIA was treated with bilayer GIC restoration followed by NC of GC-Coat Plus in class I, whereas group IIB was treated with bilayer GIC restoration followed by GC-Coat Plus in class II. Clinical analysis of all three groups was performed at 1, 3, 6, 9, and 12 months to evaluate the success of treatment procedures using predetermined criteria. Pearson's Chi-square and Kaplan-Meier estimates were utilized to evaluate the success of all four treatment procedures (p < 0.05). Results: Out of 178 teeth, 33 teeth were in group IA, 36 teeth were in group IB, 43 teeth were in group IIA, and 40 teeth were available for evaluation at the end of the 12-month follow-up period. The overall success was determined to be 81% for group IA, 79.2% for group IB, 79.5% for group IIA, and 88.6% for IIB. At 6th-month follow-up, one clinical failure was observed in groups IA and IB. At 9 months follow-up, two clinical failures were observed in both group IA and group IB and three failures were observed in group IIB. At 12 months follow-up, four clinical failures were observed in group IA, three in group IB and one clinical failure was observed in group IIB. There was no statistically significant difference observed between the success of the four groups, suggesting that either of the techniques can be utilized for ART. Conclusion: No statistically significant difference was observed between the survival of class I and class II restorations of both the groups, indicating that either single-layer or bilayer technique along with NC can be adopted for the management of dental caries in primary molars using the ART approach. How to cite this article: Khan N, Garg N, Garg N, et al. Comparative Evaluation of the Survival Rates of Atraumatic Restorative Treatment Restorations Using Bilayer Technique along with Nanofilled Coating in Primary Molars: A Clinical Study. Int J Clin Pediatr Dent 2024;17(S-1):S55-S60.

Current Approaches on Transfersomal Patch: A Noninvasive Innovative Booster for Improved Transdermal Drug Delivery.

Pharmaceutical research is increasingly focusing on transdermal drug delivery due to its potential for improved compliance and bioavailability. However, it is challenging due to the tight intracellular junctions present in the skin. Researchers have developed noninvasive methods, like transfersomes, to overcome these challenges. Transfersomes are ultra-deformable vesicles utilized for improved transdermal applications. They are made up of a phospholipid-rich lipid bilayer, an edge activator, and an ethanol/aqueous core. After topical treatment, transfersomes can penetrate deeper skin regions, delivering larger concentrations of active compounds. A transfersomal patch is applied to the skin and left for an extended period of time to allow a large dose of medication to permeate into the bloodstream. The transfersomal patch offers an advantage over the transfersomal gel because it allows the transfersomes to be applied under occlusive conditions, resulting in greater permeability, a lower amount of active medication, and a steady supply rather than a massive dose. This review represents the preparation and evaluation of transfersomal patches, recent research approaches, and future aspects of transfersomal patches. This study suggests that drug-loaded transfersomal patches could be a unique option to avoid invasive therapy.

DNA Origami - Lipid Membrane Interactions Controlled by Nanoscale Sterics.

DNA nanostructures designed to interact with bilayer membranes are of fundamental interest as they mimic biological cytoskeletons and other membrane-associated proteins for applications in synthetic biology, biosensing, and biological research. Yet, there is limited insight into how the binary interactions are influenced by steric effects produced by 3D geometries of DNA structures and membranes. This work uses a 3D DNA nanostructure with membrane anchors in four different steric environments to elucidate the interaction with membrane vesicles of varying sizes and different local bilayer morphology. It is found that interactions are significantly affected by the steric environments of the anchors -often against predicted accessibility- as well as local nanoscale morphology of bilayers rather than on the usually considered global vesicle size. Furthermore, anchor-mediated bilayer interactions are co-controlled by weak contacts with non-lipidated DNA regions, as showcased by pioneering size discrimination between 50 and 200 nm vesicles. This study extends DNA nanotechnology to controlled bilayer interactions and can facilitate the design of nanodevices for vesicle-based diagnostics, biosensing, and protocells.

pH-triggered bilayer film based on carboxymethyl cellulose/zein/Eudragit L100 with purple cabbage anthocyanin for monitoring pork freshness.

A novel pH-triggered bilayer film was composed of zein (Z), carboxymethylcellulose (CMC), Eudragit L100 (L100), and purple cabbage anthocyanin (PCA), followed by casting for monitoring pork freshness during storage at 4 °C and 25 °C. This bilayer film was employed to encapsulate anthocyanins, preventing anthocyanins oxidation and photodegradation. Additionally, under pH 6, this film ruptures and releases anthocyanins, inducing a sudden color change in the indicator film, significantly reducing errors in freshness indications. Notably, the ZCLP8% film had excellent stability and pH response properties. The performance of the ZCLP8% film in monitoring pork freshness was evaluated. When the concentration of pork TVB-N reached 15.59 mg/100 g (pH = 6.35), the bilayer film was ruptured, and the release rate of PCA was 85.52 %, which was a significant change in the color of the bilayer film compared with that at pH = 5. Therefore, this work addresses the limitation that anthocyanin-based intelligent films are subject to judgment errors when applied, opening new possibilities for food freshness differentiation monitoring.

Hydration- and Temperature-Dependent Fluorescence Spectra of Laurdan Conformers in a DPPC Membrane.

The widely used Laurdan probe has two conformers, resulting in different optical properties when embedded in a lipid bilayer membrane, as demonstrated by our previous simulations. Up to now, the two conformers' optical responses have, however, not been investigated when the temperature and the phase of the membrane change. Since Laurdan is known to be both a molecular rotor and a solvatochromic probe, it is subject to a profound interaction with both neighboring lipids and water molecules. In the current study, molecular dynamics simulations and hybrid Quantum Mechanics/Molecular Mechanics calculations are performed for a DPPC membrane at eight temperatures between 270K and 320K, while the position, orientation, fluorescence lifetime and fluorescence anisotropy of the embedded probes are monitored. The importance of both conformers is proven through a stringent comparison with experiments, which corroborates the theoretical findings. It is seen that for Conf-I, the excited state lifetime is longer than the relaxation of the environment, while for Conf-II, the surroundings are not yet adapted when the probe returns to the ground state. Throughout the temperature range, the lifetime and anisotropy decay curves can be used to identify the different membrane phases. The current work might, therefore, be of importance for biomedical studies on diseases, which are associated with cell membrane transformations.

Characterization of extended defects in 2D materials using aperture-based dark-field STEM in SEM.

Quantitative diffraction contrast analysis with defined diffraction vectors is a well-established method in TEM for studying defects in crystalline materials. A comparable transmission technique is however not available in the more widely used SEM platforms. In this work, we transfer the aperture-based dark-field imaging method from the TEM to the SEM, thus enabling quantitative diffraction contrast studies at lower voltages in SEM. This is achieved in STEM mode by inserting a custom-made aperture between the sample and the STEM detector and centering the hole on a desired reflection. To select individual reflections for dark-field imaging, we use our Low Energy Nanodiffraction (LEND) setup [Schweizer et al., Ultramicroscopy 213, 112956 (2020)], which captures transmission diffraction patterns from a fluorescent screen positioned below the sample. The aperture-based dark-field STEM method is particularly useful for studying extended defects in 2D materials, where (i) stronger diffraction at the lower voltages used in SEM is advantageous, but (ii) two-beam conditions cannot be established, making quantitative diffraction contrast analysis with standard bright-field and annular dark-field detectors impossible. We demonstrate the method by studying basal plane dislocations in bilayer graphene, which have attracted considerable research interest due to their exceptional structural and electronic properties. Direct comparison of results obtained on identical dislocations by the established TEM method and by the new aperture-based dark-field STEM method in SEM shows that a reliable Burgers vector analysis is possible by applying the well-known g·b=0 invisibility criterion. We further use the LEND setup to acquire 4D-STEM data and show that the virtual dark-field images match well with those in aperture-based dark-field STEM images for reliable Burgers vector analysis.

Functionalised Sodium-Carboxymethylcellulose-Collagen Bioactive Bilayer as an Acellular Skin Substitute for Future Use in Diabetic Wound Management: The Evaluation of Physicochemical, Cell Viability, and Antibacterial Effects.

The wound healing mechanism is dynamic and well-orchestrated; yet, it is a complicated process. The hallmark of wound healing is to promote wound regeneration in less time without invading skin pathogens at the injury site. This study developed a sodium-carboxymethylcellulose (Na-CMC) bilayer scaffold that was later integrated with silver nanoparticles/graphene quantum dot nanoparticles (AgNPs/GQDs) as an acellular skin substitute for future use in diabetic wounds. The bilayer scaffold was prepared by layering the Na-CMC gauze onto the ovine tendon collagen type 1 (OTC-1). The bilayer scaffold was post-crosslinked with 0.1% (w/v) genipin (GNP) as a natural crosslinking agent. The physical and chemical characteristics of the bilayer scaffold were evaluated. The results demonstrate that crosslinked (CL) groups exhibited a high-water absorption capacity (>1000%) and an ideal water vapour evaporation rate (2000 g/m2 h) with a lower biodegradation rate and good hydrophilicity, compression, resilience, and porosity than the non-crosslinked (NC) groups. The minimum inhibitory concentration (MIC) of AgNPs/GQDs presented some bactericidal effects against Gram-positive and Gram-negative bacteria. The cytotoxicity tests on bilayer scaffolds demonstrated good cell viability for human epidermal keratinocytes (HEKs) and human dermal fibroblasts (HDFs). Therefore, the Na-CMC bilayer scaffold could be a potential candidate for future diabetic wound care.

Van Hove Singularity-Enhanced Raman Scattering and Photocurrent Generation in Twisted Monolayer-Bilayer Graphene.

Twisted monolayer-bilayer graphene (TMBG) has recently emerged as an exciting platform for exploring correlated physics and topological states with rich tunability. Strong light-matter interaction was realized in twisted bilayer graphene, boosting the development of broadband graphene photodetectors from the visible to infrared spectrum with high responsivity. Extending this approach to the case of TMBG will help design advanced quantum nano-optoelectronic devices because of the reduced symmetry of the system. Here, we observe the formation of van Hove singularities (VHSs) in TMBG by monitoring the significant enhancement of the Raman intensity of the G peak and the intensity ratio of G and 2D peaks. The strong interlayer coupling also leads to the appearance of twist-angle-dependent Raman R and R' peaks in TMBG. Furthermore, the constructed graphene photodetectors from 13.5°-TMBG show significantly enhanced photoresponsivity (∼31 folds of monolayer graphene and ∼15 folds of trilayer graphene) when the energy of incident photons matches the interval energy between the two VHSs in the conduction and valence bands. Our findings establish TMBG as a tunable platform for investigating the light-matter interaction and designing high-performance graphene photodetectors with combined high responsivity and high selectivity.

A Bilayer Polyurethane Patch with Sustained Growth Factor Release and Antibacteria for Re-epithelization of Large-Scale Oral Mucosal Defects.

In the field of oral and maxillofacial surgery, extensive oral soft-tissue injuries occur repeatedly in clinical practice; however, effective restorative materials are lacking. In this study, a biodegradable waterborne polyurethane patch featuring a mucosa bionic bilayer structure is presented. This patch consists of a porous scaffold layer that faces the lesion, incorporating a polydopamine coating to achieve sustained release of epidermal growth factors (EGFs) for mucosal defect reconstruction. Additionally, there is a dense barrier layer toward the oral cavity loaded with silver nanoparticles, which prevents bacteria from entering the wound and simultaneously acts as a physical barrier. This patch can sustainably release EGF in vitro for 2 weeks, thereby facilitating the proliferation and migration of HaCaT and L929 cells, while effectively killing common oral cavity bacteria. In a rabbit buccal mucosal full-thickness defect model, the patch demonstrates better efficacy than the clinical benchmark, decellularized extracellular matrix (dECM). It effectively reduces wound inflammation and significantly upregulates gene expression associated with epithelialization by activating the EGF/epidermal growth factor receptor (EGFR) pathway. These mechanisms promote the proliferation, differentiation, and migration of epithelial/keratinocyte cells, ultimately expediting mucosal defect healing and wound closure.

Biomechanical features and parametric calibration of a bilayer bonded particle model for the cornstalk during harvest.

The optimal discrete element model and bonding parameters that match the structural features of cornstalks during harvest were obtained. Based on the differences in mechanical properties of the stem bark and stem pith in the inter-nodal cornstalk, the biomechanical-specific parameters were measured using the compression, shear, and bending tests. The bonded particle models of stem bark and stem pith were constructed using fraction particles with radii of 1 mm and 1.47 mm, which were further bound to form a bilayer-bonded particle model of the cornstalk. The Plackett-Burman, steepest ascent, and response surface tests were conducted to identify the factors and their optimal values that significantly impacted the stem bark-stem bark, stem pith-stem pith, and stem bark-stem pith bonding parameters. The cornstalk's shear and bending mechanical properties were assessed to verify the overall characteristic parameters. The findings revealed that the cornstalk model created, and the calibrated bonding parameters, were highly accurate and capable of simulating the shearing and bending behaviors of the real cornstalk. The inter-nodal cornstalk's bonded particle model created and the identified bonding parameters for the cornstalk could contribute to a theoretical and research basis for the next stage in cornstalk modeling with nodes and other applications.

Optimization of e-beam lithography parameters for nanofabrication of sub-50 nm gold nanowires and nanogaps based on a bilayer lift-off process.

Electron beam lithography (EBL) stands out as a powerful direct-write tool offering nanometer-scale patterning capability and is especially useful in low-volume R&D prototyping when coupled with pattern transfer approaches like etching or lift-off. Among pattern transfer approaches, lift-off is preferred particularly in research settings, as it is cost-effective and safe and does not require tailored wet/dry etch chemistries, fume hoods, and/or complex dry etch tools; all-in-all offering convenient, 'undercut-free' pattern transfer rendering it useful, especially for metallic layers and unique alloys with unknown etchant compatibility or low etch selectivity. Despite the widespread use of the lift-off technique and optical/EBL for micron to even sub-micron scales, existing reports in the literature on nanofabrication of metallic structures with critical dimension in the 10-20 nm regime with lift-off-based EBL patterning are either scattered, incomplete, or vary significantly in terms of experimental conditions, which calls for systematic process optimization. To address this issue, beyond what can be found in a typical photoresist datasheet, this paper reports a comprehensive study to calibrate EBL patterning of sub-50 nm metallic nanostructures including gold nanowires and nanogaps based on a lift-off process using bilayer polymethyl-methacrylate as the resist stack. The governing parameters in EBL, including exposure dose, soft-bake temperature, development time, developer solution, substrate type, and proximity effect are experimentally studied through more than 200 EBL runs, and optimal process conditions are determined by field emission scanning electron microscope imaging of the fabricated nanostructures reaching as small as 11 nm feature size.

Hybrid Zwitterionic Hydrogels with Encoded Differential Swelling and Programmed Deformation for Small-Scale Robotics.

Stimuli-responsive shape-morphing hydrogels with self-healing and tunable physiochemical properties are excellent candidates for functional building blocks of untethered small-scale soft robots. With mechanical properties similar to soft organs and tissues, such robots enable minimally invasive medical procedures, such as cargo/cell transportation. In this work, responsive hydrogels based on zwitterionic/acrylate chemistry with self-healing and stimuli-responsiveness are synthesized. Such hydrogels are then judiciously cut and pasted to form hybrid constructs with predetermined swelling and elastic anisotropy. This method is used to program hydrogel constructs with predetermined 2D-to-3D deformation upon exposure to different environmental ionic strengths. Untethered soft robotic functionalities are demonstrated, such as actuation, magnetic locomotion, and targeted transport of soft and light cargo in flooded media. The proposed hydrogel expands the repertoire of functional materials for fabricating small-scale soft robots.

The efficacy of reconstructive therapy in the surgical management of peri-implantitis: A 3-year follow-up of a randomized clinical trial.

AIM: To assess whether guided bone regeneration (GBR) treatment of peri-implantitis-related bony defects could improve healing compared to open flap debridement (OFD) at 36 months. MATERIALS AND METHODS: In a multi-centre, randomized clinical trial, 32 individuals received OFD (control group [CG]) and 34 GBR treatment (test group [TG]). Radiographic defect fill (RDF), probing pocket depth (PPD), bleeding on probing (BOP) suppuration (SUP), mucosal recession (MREC) and patient-reported outcomes (PROs) were evaluated at 36 months. RESULTS: Fifty individuals attended a supportive peri-implant therapy program and completed the 36-month follow-up. GBR treatment resulted in an RDF of 2.13 ± 1.26 mm compared to 1.64 ± 1.54 mm following OFD (p = .18). No difference was found in PPD, BOP, SUP, REC or PROs between the groups. Successful treatment (no additional bone loss, PPD ≤ 5 mm, no BOP and no SUP) was achieved in 46.2% in TG and 20% in CG (p = .053). Treatment results obtained at 12 months were generally maintained up to 36 months. No significant changes were noticed between 12 and 36 months. CONCLUSIONS: At 36 months, treatment results obtained at 1 year were sustained following both GBR and OFD in patients attending supportive peri-implant therapy. GBR resulted in more RDF and higher composite treatment success rate than OFD (ClinicalTrials.gov Identifier [NCT02375750]).

Phase separation in model lipid membranes investigated with cryogenic electron microscopy.

We describe a method for investigating lateral membrane heterogeneity using cryogenic electron microscopy (cryo-EM) images of liposomes. The method takes advantage of differences in the thickness and molecular density of ordered and disordered phases that are resolvable in phase contrast cryo-EM. Compared to biophysical techniques like FRET or neutron scattering that yield ensemble-averaged information, cryo-EM provides direct visualization of individual vesicles and can therefore reveal variability that would otherwise be obscured by averaging. Moreover, because the contrast mechanism involves inherent properties of the lipid phases themselves, no extrinsic probes are required. We explain and discuss various complementary analyses of spatially resolved thickness and intensity measurements that enable an assessment of the membrane's phase state. The method opens a window to nanodomain structure in synthetic and biological membranes that should lead to an improved understanding of lipid raft phenomena.