Honeycomb Architecture Research Articles

3D printed SiOC architecture towards terahertz electromagnetic interference shielding and absorption

Electromagnetic interference (EMI) shielding and absorption materials can effectively mitigate the undesired pollution or noise caused by terahertz (THz) waves. The development of THz EMI shielding materials that are primarily based on absorption mechanisms to avoid secondary pollution caused by reflection is still in big demand. Herein, an absorption-dominated precursor-derived SiOC ceramic (PDC-SiOC) architecture for THz wave EMI shielding and absorption was reported. The EMI shielding properties of the bulk SiOC ceramic were studied. More than 93 % of THz EM waves were absorbed by the synthesized SiOC ceramic from 1.2 to 1.6 THz. Furthermore, lightweight honeycomb-structured SiOC architecture which was inspired by the wings of moth was fabricated by vat photopolymerization 3D printing combined with following pyrolysis. The EMI shielding properties and mechanism of the honeycomb SiOC architecture in THz bands were also discussed. The highest shielding effectiveness (SE) of the honeycomb SiOC architecture was up to 64.1 dB, and the transmissivity was below 1.4 % from 0.2 to 1.6 THz. In addition, more than 97–99.8 % of THz waves were absorbed in 0.8–1.6 THz. The excellent EMI shielding performance of the architecture was mainly attributed to its outstanding THz EM wave absorption ability. Finally, the mechanical properties and thermal stability of the architecture were further studied. The compressive and flexural strength of honeycomb architecture was 1.2 and 16.5 MPa, respectively. The result also proved that the honeycomb SiOC architecture was resistant to high temperatures up to 1100 °C under inert atmosphere. This work provides promising high-efficiency architecture towards THz EMI shielding and absorption.

Diagnostic Assessment of Endoscopic Ultrasonography-Fine Needle Aspiration Cytology in the Pancreas: A Comparison between Liquid-Based Preparation and Conventional Smear.

Background and Objectives: This study aimed to elucidate the cytologic characteristics and diagnostic usefulness of endoscopic ultrasonography-fine needle aspiration cytology (EUS-FNAC) by comparing it with liquid-based preparation (LBP) and conventional smear (CS) in pancreas. Methods: The diagnostic categories (I through VII) were classified according to the World Health Organization Reporting System for Pancreaticobiliary Cytopathology. Ten cytologic features, including nuclear and additional features, were evaluated in 53 cases subjected to EUS-FNAC. Nuclear features comprised irregular nuclear contours, nuclear enlargement, hypochromatic nuclei with parachromatin clearing, and nucleoli. Additional cellular features included isolated atypical cells, mucinous cytoplasm, drunken honeycomb architecture, mitosis, necrotic background, and cellularity. A decision tree analysis was conducted to assess diagnostic efficacy. Results: The diagnostic concordance rate between LBP and CS was 49.1% (26 out of 53 cases). No significant differences in nuclear features were observed between categories III (atypical), VI (suspicious for malignancy), and VII (malignant). The decision tree analysis of LBP indicated that cases with moderate or high cellularity and mitosis could be considered diagnostic for those exhibiting nuclear atypia. Furthermore, in CS, mitosis, isolated atypical cells, and necrotic background exerted a more significant impact on the diagnosis of EUS-FNAC. Conclusions: Significant parameters for interpreting EUS-FNAC may differ between LBP and CS. While nuclear atypia did not influence the diagnosis of categories III, VI, and VII, other cytopathologic features, such as cellularity, mitosis, and necrotic background, may present challenges in diagnosing EUS-FNAC.

Nodes for modes: Nodal honeycomb metamaterial enables a soft robot with multimodal locomotion

Soft-bodied animals, such as worms and snakes, use many muscles in different ways to traverse unstructured environments and inspire tools for accessing confined spaces. They demonstrate versatility of locomotion which is essential for adaptation to changing terrain conditions. However, replicating such versatility in untethered soft-bodied robots with multimodal locomotion capabilities have been challenging due to complex fabrication processes and limitations of soft body structures to accommodate hardware such as actuators, batteries and circuit boards. Here, we present MetaCrawler, a 3D printed metamaterial soft robot designed for multimodal and omnidirectional locomotion. Our design approach facilitated an easy fabrication process through a discrete assembly of a modular nodal honeycomb lattice with soft and hard components. A crucial benefit of the nodal honeycomb architecture is the ability of its hard components, nodes, to accommodate a distributed actuation system, comprising servomotors, control circuits, and batteries. Enabled by this distributed actuation, MetaCrawler achieves five locomotion modes: peristalsis, sidewinding, sideways translation, turn-in-place, and anguilliform. Demonstrations showcase MetaCrawler’s adaptability in confined channel navigation, vertical traversing, and maze exploration. This soft robotic system holds the potential to offer easy-to-fabricate and accessible solutions for multimodal locomotion in applications such as search and rescue, pipeline inspection, and space missions.

Investigating the interplay between environmental conditioning and nanotopographical cueing on the response of human MG63 osteoblastic cells to titanium nanotubes.

Titanium nanotubular surfaces have been extensively studied for their potential use in biomedical implants due to their ability to promote relevant phenomena associated with osseointegration, among other functions. However, despite the large body of literature on the subject, potential synergistic/antagonistic effects resulting from the combined influence of environmental variables and nanotopographical cues remain poorly investigated. Specifically, it is still unclear whether the nanotube-induced variations in cellular activity are preserved across different biochemical contexts. To bridge this gap, this study systematically evaluates the combined influence of nanotopographical cues and environmental factors on human MG63 osteoblastic cells. To this end, we capitalized on a triphasic anodization protocol to create nanostructured surfaces characterized by an average nanotube inner diameter of 25 nm (NT1) and 82 nm (NT2), as well as a two-tiered honeycomb (HC) architecture. A variable glucose content was chosen as the environmental modifier due to its well-known ability to affect specific functions of MG63 cells. Alkaline phosphatase (ALP), viability/metabolic activity and proliferation were quantified to identify the suitable preconditioning window required for dictating a change in behaviour without significantly damaging cells. Successively, a combination of immunofluorescence, colorimetric assays, live cell imaging and western blots quantified viability/metabolic activity and cell proliferation, migration and differentiation as a function of the combined effects exerted by the nanostructured substrates and the glucose content. To achieve a thorough understanding of MG63 cell adaptation and response, a comparative analysis table that includes and systematically cross-analyzes all variables from this study was used for interpretation and discussion of the results. Taken together, we have demonstrated that all surfaces mitigate the negative effects of high glucose. However, nanotubular topographies, particularly NT2, elicit a more beneficial outcome in high glucose in respect to untreated titanium. In addition, while NT1 surfaces are associated with the most stable cellular response across varying glucose levels, the NT2 and HC substrates exhibit the strongest enhancement of cell migration, viability/metabolism and differentiation. Moreover, shorter-term processes such as adhesion and proliferation are favored on untreated titanium, while anodized samples support later-term events. Lastly, the role of anodized surfaces is dominant over the effects of environmental glucose, underscoring the importance of carefully considering nanoscale surface features in the design and development of cell-instructive titanium surfaces.

A cross-scale honeycomb architecture-based flexible piezoresistive sensor for multiscale pressure perception and fine-grained identification.

Trade-off between sensitivity and the pressure sensing range remains a great challenge for flexible pressure sensors. Micro-nano surface structure-based sensors usually show high sensitivity only in a limited pressure regime, while porous structure-based sensors possess a broad pressure-response range with sensitivity being sacrificed. Here, we report a design strategy based on a cross-scale architecture consisting of a microscale tip and macroscale base, which provides continuous deformation ability over a broad pressure regime (10-4-104 kPa). The cross-scale honeycomb architecture (CHA)-based piezoresistive sensor exhibits an excellent sensitivity over a wide pressure range (0.5 Pa-0.56 kPa: S1 ∼ 27.97 kPa-1; 0.56-20.40 kPa: S2 ∼ 2.30 kPa-1; 20.40-460 kPa: S3 ∼ 0.13 kPa-1). As a result, the CHA-based sensor shows multiscale pressure perception and fine-grained identification ability from 0.5 Pa to 40 MPa. Additionally, the cross-scale architecture will be a general structure to design other types of sensors for highly sensitive pressure perception in a wide pressure range and its unit size from microscale to macroscale is beneficial for large-scale preparation, compared with micro-nano surface structures or internal pores.

Investigation of air bubble behaviour after gas embolism events induced in a microfluidic network mimicking microvasculature.

Gas embolism is a medical condition that occurs when gas bubbles are present in veins or arteries, decreasing blood flow and potentially reducing oxygen delivery to vital organs, such as the brain. Although usually reported as rare, gas embolism can lead to severe neurological damage or death. However, presently, only limited understanding exists regarding the microscale processes leading to the formation, persistence, movement, and resolution of gas emboli, as modulated by microvasculature geometrical features and blood properties. Because gas embolism is initially a physico-chemical-only process, with biological responses starting later, the opportunity exists to fully study the genesis and evolution of gas emboli using in vitro microfluidic networks mimicking small regions of microvasculature. The microfluidics networks used in this study, which aim to mimic microvasculature geometry, comprise linear channels with T-, or Y-junction air inlets, with 20, 40, and 60 μm widths (arterial or venous), and a 30 μm width honeycombed network (arterial) with three bifurcation angles (30°, 60°, and 90°). Synthetic blood, equivalent to 46% haematocrit concentrations, and water were used to study the modulation of gas embolism-like events by liquid viscosity. Our study shows that (i) longer bubbles with lower velocity occur in narrower channels, e.g., with 20 μm width; (ii) the resistance of air bubbles to the flow increases with the higher haematocrit concentration; and lastly (iii) the propensity of gas embolism-like events in honeycomb architectures increases for more acute, e.g., 30°, bifurcation angles. A dimensionless analysis using Euler, Weber, and capillary numbers demarcated the conditions conducive to gas embolism. This work suggests that in vitro experimentation using microfluidic devices with microvascular tissue-like structures could assist medical guidelines and management in preventing and mitigating the effects of gas embolism.

Size-regulated Co-doped hetero-interfaced 3D honeycomb MXene as high performance electromagnetic absorber with anti-corrosion performance

It is desirable to develop electromagnetic (EM) wave absorbers with anti-corrosion property that can suit various electronics, telecommunications, and military applications in harsh conditions. In this work, by varying the Co content in the 3D honeycomb MXene, Co/MXene composites with remarkable EM absorption performance were obtained. In particular, Co/MXene with 0.5 mmol Co displayed a minimum reflection loss (RL) of –54.3 dB at 2.34 mm and broad absorption bandwidth of 5.92 GHz at 2.02 mm. These Co/MXene composites also showed high resistance to corrosion as evidenced by very low corrosion current densities (10−6 ∼ 10−7 A cm−2) and very large polarization resistances (107 ∼ 108 Ω) when exposed to various corrosive conditions (acid, neutral, and alkaline conditions). The unique honeycomb architecture and the combined presence of Co and MXene enabled the electron transfer from Co to MXene as revealed by density functional theory simulation and suppressed the contributions from magnetic and conductive losses, thus allowing only polarization loss-originated EM dissipation behavior. Accordingly, this study introduces a simplified model to elucidate the mechanism of EM absorption, offering insights at the nano level.

Controllable microfluidic fabrication of honeycomb capsule adsorbent via the one-step titration-gel method

The hydrogel capsule adsorbent with honeycomb architectures was prepared via the one-step titration-gel method (OSTGM), which the casting solution contained polyvinyl alcohol (PVA), sodium alginate (SA) and tetraethyl orthosilicate (TEOS) were directly dripped into CaCl2 and H3BO3 aqueous mixture through a controllable microfluidic device. The microscopic morphology and adsorbed capacity of the SA-PVA-SiO2 capsules (SPSC) were absolutely depended on the parameter conditions during preparation. In this paper, at optimal synthesis situations [SA: PVA = 3: 7 (w: w), TEOS: (SA-PVA) = 2: 30 (v: w), the titration-gel distance was 14 cm and the feed flowed rate was 13 mL/h], the maximal removed capacity of the MB by the SPSC was 392.54 mg/g, and the SiO2 NPs accounted for 17.94 wt % of the polymers. The prepared SPSC, also, could work in overly acid and alkaline aqueous solutions (pH 1-13). The authors of this manuscript hoped this work would provide a corresponding guideline for the researchers who are aiming at preparing the spherical hydrogel adsorbents for waste water treatments.

3D Honeycomb Fe/MXene Derived from Prussian Blue Microcubes with a Tunable Structure for Efficient Low-Frequency and Flexible Electromagnetic Absorbers.

The unique layered structure and high conductivity of MXene materials make them highly promising for microwave absorption. However, the finite loss mechanism and severe agglomeration present challenging obstacles for ideal microwave absorbers, which could be effectively improved by constructing a three-dimensional (3D) porous structure. This study reports a 3D honeycomb MXene using a straightforward template method. The 3D MXene framework offers ample cavities to anchor the Prussian blue microcubes and their derivatives including Fe microboxes and Fe clusters by a simple annealing process. Based on the superiority of the 3D honeycomb architecture and magnetic-dielectric synergistic effects, the Fe/MXene absorbers demonstrate outstanding microwave absorption capabilities with the optimum reflection loss value of -40.3 dB at 2.00 mm in the low-frequency range from 4.2 to 5.6 GHz. The absorber also manifests superior radar wave attenuation by finite element analysis and exhibits great potential to be a flexible and thermal insulation material in a wide range of temperatures. This work proposes a useful reference for the design of 3D MXene-based porous architectures, and the synergistic magnetic-dielectric strategy further expands the potential of MXene-based absorbers, enabling them to be used as flexible and highly efficient microwave absorbers.

Two-Dimensional Silver-Chalcogenolate-Based Cluster-Assembled Material: A p-type Semiconductor.

We have synthesized and characterized a new two-dimensional honeycomb architecture resembling a single-layer of atomically precise silver cluster-assembled material (CAM), [Ag12(StBu)6(CF3COO)6(4,4'-azopyridine)3] (Ag12-azo-bpy). The interlayer noncovalent van der Waals interactions within the single-crystals were successfully disrupted, leading to the creation of this unique structure. The optimized Ag12-azo-bpy CAM demonstrates a valence band that is localized on the Ag12 cluster node situated near the Fermi energy level. This localization induces electron injection from the linker to the cluster node, facilitating efficient charge transportation along the plane. Exploiting this single-layer structure as a distinctive platform for p-type channel material, it was employed in a field-effect transistor configuration. Remarkably, the transistor exhibits a high hole mobility of 1.215 cm2 V-1 s-1 and an impressive ON/OFF current ratio of ∼4500 at room-temperature.

Towards 3D Lithium-Ion Full Cells Using Honeycomb-Patterned Carbon Nanotube Forests

The growing demand for electric vehicles and portable electronics has created a significant interest in the scalability, recyclability, and economics of both traditional and emerging battery technologies. Although lithium-ion batteries (LiB) are approaching their theoretical energy density, they will remain a widespread and promising technology as alternative (e.g., Li-metal) chemistries and solid-state architectures are still in relatively early stages of commercial scale-up. Yet, LiB performance can be improved by redesigning the cell geometry to move from planar to 3D designs. 3D designs enable the use of thick electrodes to increase the cell level energy density by minimizing the volume and mass contributions of inactive components, such as current collectors or separators. The rationale for 3D full cell designs lies in the relationship between electrode geometry and the respective energy and power densities. When compared to a planar design, 3D architectures allow for a higher surface area for the same volume and footprint of cell. As a result, a given volume of active material can be distributed with a lower electrode feature thickness. Compared to a planar electrode of a given energy density, the lower thickness contributes to a quadratic improvement in power density which decouples the inherent tradeoff between the energy density and power density that is experienced by planar cells. This suggests that a high aspect ratio 3D cell would give greater power per footprint area while retaining high areal energy density. To meet these criteria, the materials used in fabricating 3D cells must be processable in a manner enabling precise control over geometry, layer conformality and porosity.We are developing thick 3D “honeycomb” full cells by starting with patterned, vertically aligned carbon nanotubes (VA-CNTs) as current collectors. CNTs are widely known to have high thermal and electrical conductivities, and to be mechanically durable; properties which make them an ideal scaffold for 3D cell development. VA-CNTs (“forests”) form by self-organization of CNTs during chemical vapor deposition (CVD) on substrates using common hydrocarbon sources (e.g., C2H2, C2H4). However, well-established CNT growth techniques utilize rigid non-conductive substrates, such as silicon wafers, which necessitates a transfer to a suitable substrate for electrochemical applications. Recently, we translated insights from CNT growth on silicon wafer substrates to grow CNT forests on thin metal foils (Cu) suitable for electrode fabrication. We did this by optimizing the moisture level within the CVD furnace, and using a thin-film stack that forms high-density nanoparticles upon annealing while preventing the poisoning of the Fe catalyst by diffusion of Cu. The resulting CNT forests can reach thicknesses over 350 μm and can be grown from patterned catalyst films having regular hole arrays with feature sizes as small as ~5 μm.Thick composite electrodes are then created by coating CNT forests with Si thin films by CVD. The inherent nanoporosity of the CNT forests (>95%) allows for precursor diffusion into the entirety of the forest cross-section and conformal coating of the individual CNTs. The CVD process is tuned to create dense electrodes with tailored Si loading that can range from ~10 to ~90 at.%. Half-cells using monolithic and honeycomb patterned Si-CNT electrodes (~250 μm tall), Li-metal foil, and a liquid electrolyte/separator combination have been cycled over a range of current densities, demonstrating the electronic connection between the deposited Si and Cu foil via the aligned CNTs. At low current densities and high Si loadings these honeycomb electrodes can exhibit large gravimetric (~1500 mAh/gSi) and areal (~12 mAh/cm2) capacities, with honeycomb Si-CNT composites exhibiting reduced capacity fading when compared to non-patterned electrodes.We continue by investigating these Si-CNT composites as a template for a 3D full cell design. In literature, the difficulty of producing 3D full cells comes from the need to produce high conformality electrolyte films that are pinhole free and which demonstrate sufficient ionic conductivity. To address this issue, we utilize an initiated chemical vapor deposition (iCVD) process to deposit conformal poly(hydroxyethyl methacrylate-co-ethylene glycol diacrylate) thin films on the high aspect ratio CNT forests. These copolymer films are doped with lithium salts to exhibit ionic conductivities on the order of ~10-6 to 10-5 S/cm, which is among the highest conductivities ever exhibited by conformal electrolyte technologies. To complete a full cell design, a slurry-based cathode will be infiltrated into the iCVD coated Si-CNT composite electrodes, from which we aim to assess the cycling behavior and compare the areal energy and power densities of non-patterned and honeycomb architectures.

Study on the Bending Behaviors of a Novel Flexible Re-Entrant Honeycomb

Abstract In order to further improve the bending performance of the traditional re-entrant (RE) honeycomb, a novel auxetic honeycomb architecture, called RE-L honeycomb, was proposed by adding an additional link-wall structure to the RE cell. The bending behaviors of the novel RE-L honeycomb, including the properties under linear elastic deformation and the bending behaviors under large deformation, were comprehensively investigated by the analytical, numerical, and experimental models. Results show that the proposed RE-L honeycomb significantly improves the bending compliance in the x-direction due to the highly flexible performance of the additional structure, where the bending rigidity and the maximum bending force are only 23% and 29.4% of those of the RE honeycomb, respectively. Besides, the additional structure obviously improves the designability and orthotropic properties of the original auxetic honeycomb. In conclusion, the proposed RE-L shows improved bending performance, which deserves more attention in future research and related applications.

A transceiver integrated piezoelectric micromachined ultrasound transducer array for underwater imaging

In this article, a scandium-doped aluminum nitride (Sc0.2Al0.8N) piezoelectric micromachined ultrasound transducer (PMUT) array for underwater imaging is presented. The reported PMUT array integrates a transmitter and a receiver in one transduction cell, in which the outer top electrode is used for transmitting while the inner top electrode is employed for simultaneously receiving ultrasonic waves, respectively. A 7 × 8 transduction cell array with characteristic size of 500μm is designed in a bioinspired honeycomb architecture and developed based on a piezoelectric on silicon-on-insulator (SOI) platform. The top electrode of the transduction cell is split into the outer and inner sections with the optimized size ratio for achieving transceiver integration in one cell. The fabricated PMUT array exhibits a transmit sensitivity of 146.59 dB (re: 1 μPa/V), and a receive sensitivity of −173.70 dB (re: 1 V/μPa) at its resonant frequency of around 150 kHz in water. In order to demonstrate the feasibility of underwater imaging, the PMUT array and its signal conditional circuits are packaged using an acoustically transparent material. Ultrasonic pulse-echo imaging with the developed PMUT array is demonstrated without implementation of a switching circuit to separate the transmit and reflected signals, due to the transceiver integration approach proposed in our work. This work demonstrates the feasibility of underwater imaging for the transceiver integrated PMUT array, which has great commercial value for minimized and portable underwater imaging.

Yeast biomass ornamented macro-hierarchical chitin nanofiber aerogel for enhanced adsorption of cadmium(II) ions

There is an urgent need to develop sustainable, renewable, and environment-friendly adsorbents to rectify heavy metals from water. In the current study, a green hybrid aerogel was prepared by immobilizing yeast on chitin nanofibers in the presence of a chitosan interacting substrate. A cryo-freezing technique was employed to construct a 3D honeycomb architecture comprising the hybrid aerogel with excellent reversible compressibility and abundant water transportation pathways for the accelerated diffusion of Cadmium(II) (Cd(II)) solution. This 3D hybrid aerogel structure offered copious binding sites to accelerate the Cd(II) adsorption. Moreover, the addition of yeast biomass amplified the adsorption capacity and reversible wet compression of hybrid aerogel. The monolayer chemisorption mechanism explored by Langmuir and pseudo-second-order kinetic exhibited a maximum adsorption capacity of 127.5 mg/g. The hybrid aerogel demonstrated higher compatibility for Cd(II) ions as compared to the other coexisted ions in wastewater and manifested a better regeneration potential following four consecutive sorption-desorption cycles. Complexation, electrostatic attraction, ion-exchange and pore entrapment were perhaps major mechanisms involved in the removal of Cd(II) revealed by XPS and FT-IR. This study unveiled a novel avenue for efficient green-synthesized hybrid aerogel that may be sustainably used as an excellent purifying agent for Cd(II) removal from wastewater.

Multifunctional auxetic and honeycomb composites made of 3D woven carbon fibre preforms

Three dimensional (3D) woven composites started to find applications in various industrial sectors, mainly in aerospace and with a potential in automotive. 3D-woven fabrics can be architected to form complex and near-net-shape preforms ready for automated composites manufacturing. The 3D-woven honeycomb fabric is designed to include additional functionality into finished composites, such as positive and negative Poisson's ratios. In this study, complex honeycomb architectures were created using various weave designs to demonstrate the effects of auxetic behaviours when manufactured into a composite structure. A Staubli 3D-weaving system equipped with Jacquard UNIVAL 100 and creel of 3072 6 k carbon fibre tows were used to weave the designed honeycomb architecture. With the aid of hard polyester foam inserts, the 3D-woven fabrics were converted to honeycomb and auxetic preforms. These preforms were infused using epoxy resin to manufacture a set of honeycomb and auxetic composite structures. In comparison with the baseline honeycomb structure, it is proven that the developed auxetic composites exhibited negative Poisson’s ratio of − 2.86 and − 0.12 in the case of tensile and compression tests respectively.

Cobalt-embedded 3D conductive honeycomb architecture to enable high-sulphur-loading Li-S batteries under lean electrolyte conditions

Cobalt-embedded 3D conductive honeycomb architecture to enable high-sulphur-loading Li-S batteries under lean electrolyte conditions

Enhanced Cellular Materials through Multiscale, Variable-Section Inner Designs: Mechanical Attributes and Neural Network Modeling.

In the current work, the mechanical response of multiscale cellular materials with hollow variable-section inner elements is analyzed, combining experimental, numerical and machine learning techniques. At first, the effect of multiscale designs on the macroscale material attributes is quantified as a function of their inner structure. To that scope, analytical, closed-form expressions for the axial and bending inner element-scale stiffness are elaborated. The multiscale metamaterial performance is numerically probed for variable-section, multiscale honeycomb, square and re-entrant star-shaped lattice architectures. It is observed that a substantial normal, bulk and shear specific stiffness increase can be achieved, which differs depending on the upper-scale lattice pattern. Subsequently, extended mechanical datasets are created for the training of machine learning models of the metamaterial performance. Thereupon, neural network (NN) architectures and modeling parameters that can robustly capture the multiscale material response are identified. It is demonstrated that rather low-numerical-cost NN models can assess the complete set of elastic properties with substantial accuracy, providing a direct link between the underlying design parameters and the macroscale metamaterial performance. Moreover, inverse, multi-objective engineering tasks become feasible. It is shown that unified machine-learning-based representation allows for the inverse identification of the inner multiscale structural topology and base material parameters that optimally meet multiple macroscale performance objectives, coupling the NN metamaterial models with genetic algorithm-based optimization schemes.

Novel artificial muscle using shape memory alloy spring bundles in honeycomb architecture in Bi-directions

Novel artificial muscle using shape memory alloy spring bundles in honeycomb architecture in Bi-directions

Cytology of Bile Duct Brushings: Streaming Ahead with Time

Endoscopic retrograde brush cytology of the biliary duct is an established tool for evaluation of obstructive biliary strictures or screening of primary sclerosing cholangitis (PSC) patients for dysplasia. It is a simple, minimally invasive procedure that can be performed during a therapeutic ERCP. Most authors have reported a sensitivity of 30-60% and a specificity of 90-100%. A positive result can be a reliable indicator of malignant neoplasm. However, there is no standardized reporting terminology designed specifically for bile duct brushings. Majority of bile duct brushings yield either benign ductal epithelium, reactive atypia of ductal epithelium or suspicious/positive for malignancy. Diagnosing malignancy in bile duct brushings is based on a constellation of cytologic features, and consideration of the overall picture- clinical presentation, radiology/endoscopy findings, etc. Different studies have highlighted various key features for diagnosing malignancy in bile duct brushings. Features most consistently associated with a malignant category are- loss of honeycomb architecture, 3D clusters, high n:c ratio, anisonucleosis (≥1:4 variation), irregular nuclear outlines, coarse clumped chromatin, and single malignant cells in the background. The utility of biliary brush cytology has been expanded by using FISH, immunocytochemistry, and Next-generation sequencing.

Biobased hierarchically porous carbon featuring micron-sized honeycomb architecture for CO2 capture and water remediation

Hierarchically porous carbon (HPC) has exhibited exceptional performance in environmental-related applications; however, the synthesis of high-efficient biobased HPCs remains a challenge because of the inherent structure and chemical composition complexities of biomass. Here, we prepare high-efficient biobased HPC sorbents featuring uniform micron-sized (~20 µm) honeycomb cells and abundant meso- and micropores through combining the selection of biomass precursors and the corresponding synthetic strategies. Cork is selected as the precursor because of its distinctive hollow polyhedral cellular structure and unique chemical composition composed of suberin. ZnCl2 is selected as the activation reagent due to its mild activation effect with less carbon etching and recyclability. The sequential low-temperature pretreatment and ZnCl2 activation processes produce high-efficient HPC sorbent for CO2 capture and water decontamination. Results show that cork-based HPC poses high carbon yield (> 80 wt%), large specific surface area (up to 1853 m2/g), and high pore volume (up to 0.839 cm3/g). Accordingly, cork-based HPC exhibit high CO2 capture performance (e.g., 4.64 mmol/g at 0 °C), superior adsorption capacity for methylene blue (887.7 mg/g) and lead ion (Pb2+, 74.3 mg/g), and fast uptake speed for contaminants (i.e., < 5 min). Moreover, approximately 80% of ZnCl2 can be recycled and reused. This study demonstrates a sustainable and cost-effective process for producing high-efficient HPCs from cork for environmental applications.