Embedded Direct Ink Writing 3D Printing of UV Curable Resin/Sepiolite Composites with Nano Orientation.

Among the various 3D printing methods, direct ink writing (DIW) through extrusion directly affects the microstructure and properties of materials. However, use of nanoparticles at high concentrations is restricted due to difficulties in sufficient dispersion and the deteriorated physical properties of nanocomposites. Thus, although there are many studies on filler alignment with high-viscosity materials with a weight fraction higher than 20 wt %, not much research has been done with low-viscosity nanocomposites with less than 5 phr. Interestingly, the alignment of anisotropic particles improves the physical properties of the nanocomposite at a low concentration of nanoparticles with DIW. The rheological behavior of ink is affected by the alignment of anisotropic sepiolite (SEP) at a low concentration using the embedded 3D printing method, and silicone oil complexed with fumed silica is used as a printing matrix. A significant increase in mechanical properties is expected compared to conventional digital light processing. We clarify the synergistic effect of the SEP alignment in a photocurable nanocomposite material through physical property investigations.

Novel characteristics of soluble fibrin: hypercoagulability and acceleration of blood sedimentation rate mediated by its generation of erythrocyte-linked fibers.

Soluble fibrin (SF) in blood consists of monomers lacking both fibrinopeptides A with a minor population in multimeric clusters. It is a substantial component of isolated fibrinogen (fg), which spontaneously self-assembles into protofibrils progressing to fibers at sub-physiologic temperatures, a process enhanced by adsorption to hydrophobic and some metal surfaces. Comparisons of SF-rich (FR) and SF-depleted (FD) fg isolates disclosed distinct molecular imprints of each via an adsorption/desorption procedure using gold surfaced silica microplates. Accelerated plasminogen activator-induced lysis and decreased stiffness (G') of thrombin-induced FR fg clots were revealed by thomboelastography. Erythrocyte sedimentation (ESR) in afibrinogenemic plasma (Hematocrit 25-33%) was accelerated by FR fg nearly threefold that of FD fg. Stained smears disclosed frequent rouleaux formations and fibers linking stacked erythrocytes in contrast to no rouleaux by FD fg. Rouleaux formations were more pronounced at 4 °C than at ambient temperatures and at fiber-membrane contacts displayed irregular, knobby membrane contours. One of several FR fg isolates also displayed incomplete fiber networks in cell-free areas. What is more, pre-mixing FR fg with each of three monoclonal IgG anti-fg antibodies at 1.5 mol/mol fg, that inhibited fibrin polymerization, prevented rouleaux formation save occasional 2-4 erythrocyte aggregates. We conclude that spontaneously generated SF fibers bound to erythrocytes forming intercellular links culminating in rouleaux formation and ensuing ESR acceleration which in clinical settings reflects hypercoagulability. Also, the results can explain the reported fg binding to erythrocytes via ligands such as CD47, stable in vivo RBC aggregates in capillaries, and red areas of pathologic thrombi.

Multifunctional and thermoresponsive methylcellulose composite hydrogels with photothermal effect.

Multifunctional and thermoresponsive hydrogels can be used as soft materials in various medical applications, such as beauty devices, drug delivery, and near-infrared (NIR) lasers. In this study, methylcellulose (MC) composite hydrogels containing tannic acid (TA) and Fe3+ were prepared via a simple, fast process. The MC composite hydrogel contains hydrogen bonds between the MC polymer and TA and coordination bonds between TA and Fe3+, without losing the reversible thermogelation properties of the MC polymer. The gelation rates and mechanical properties of the MC composite hydrogel were controlled by varying its TA and Fe3+ contents. In particular, the hydrogel with a TA-Fe chelating complex showed an excellent photothermal effect, indicating its potential application in cosmetic beauty devices. It also exhibited UV-blocking, antioxidant, and antibacterial properties owing to the multifunctional TA. The facile processing of these MC/TA/Fe hydrogels provides new opportunities for biomedical applications and beauty devices employing NIR laser therapy.

Stretchable and Self-Healable Poly(styrene-co-acrylonitrile) Elastomer with Metal-Ligand Coordination Complexes.

Recently, soft electronics have attracted significant attention for various applications such as flexible devices, artificial electronic skins, and wearable devices. For practical applications, the key requirements are an appropriate electrical conductivity and excellent elastic properties. Herein, using the cyano-silver complexes resulting from coordination bonds between the nitrile group of poly(styrene-co-acrylonitrile) (SAN) and Ag ions, a self-healing elastomer demonstrating electrical conductivity is obtained. Because of these coordination complexes, the Ag-SAN elastomer possesses elasticity, compared with pristine SAN. The fracture strain of the Ag-SAN elastomers increased with the amount of added Ag ions, reaching up to 1000%. Additionally, owing to the presence of reversible coordination bonds, the elastomer exhibits self-healing properties at room temperature and electrical conductivity, thereby improving the possibility of its utilization in novel applications wherein elastic materials are generally exposed to external stimuli.

Efficacy of Immunohistochemistry for SDHB in the Screening of Hereditary Pheochromocytoma-Paraganglioma.

The most common genetic backgrounds of hereditary paraganglioma and pheochromocytoma (PPGL) are SDHx germline mutations. Given the fact that the immunohistochemistry (IHC) result for SDHB is always negative regardless of the type of SDHx mutation, we aimed to evaluate the efficacy of using SDHB IHC for screening SDHx mutations in PPGL cases. In total, 52 patients who underwent surgery for PPGL treatment between 2006 and 2020 and underwent genetic analysis at diagnosis were included. Tissue microarrays (TMAs) were constructed with PPGL tissues and IHC for SDHB was performed on TMA sections. All 10 patients with SDHB-negative IHC contained SDHB or SDHD mutations. The genetic test results of patients with SDHB-weakly positive IHC varied (one SDHB, two RET, one VHL, and three unknown gene mutations). There were no SDHx mutations in the SDHB-positive IHC group. Six patients with weakly positive SDHB IHC with primarily unknown genetic status were re-called and underwent next-generation sequencing. None of them had SDHx mutations. In conclusion, SDHB-negative IHC is a cost-effective and reliable method to predict SDHx mutations. However, in the case of weakly positive SDHB staining, an additional gene study should be considered.

Fibers Generated by Plasma Des-AA Fibrin Monomers and Protofibril/Fibrinogen Clusters Bind Platelets: Clinical and Nonclinical Implications.

Objective Soluble fibrin (SF) is a substantial component of plasma fibrinogen (fg), but its composition, functions, and clinical relevance remain unclear. The study aimed to evaluate the molecular composition and procoagulant function(s) of SF. Materials and Methods Cryoprecipitable, SF-rich (FR) and cryosoluble, SF-depleted (FD) fg isolates were prepared and adsorbed on one hydrophilic and two hydrophobic surfaces and scanned by atomic force microscopy (AFM). Standard procedures were used for fibrin polymerization, crosslinking by factor XIII, electrophoresis, and platelet adhesion. Results Relative to FD fg, thrombin-induced polymerization of FR fg was accelerated and that induced by reptilase was markedly delayed, attributable to its decreased (fibrinopeptide A) FpA. FR fg adsorption to each surface yielded polymeric clusters and co-cryoprecipitable solitary monomers. Cluster components were crosslinked by factor XIII and comprised ≤21% of FR fg. In contrast to FD fg, FR fg adsorption on hydrophobic surfaces resulted in fiber generation enabled by both clusters and solitary monomers. This began with numerous short protofibrils, which following prolonged adsorption increased in number and length and culminated in surface-linked three-dimensional fiber networks that bound platelets. Conclusion The abundance of adsorbed protofibrils resulted from (1) protofibril/fg clusters whose fg was dissociated during adsorption, and (2) adsorbed des-AA monomers that attracted solution counterparts initiating protofibril assembly and elongation by their continued incorporation. The substantial presence of both components in transfused plasma and cryoprecipitate augments hemostasis by accelerating thrombin-induced fibrin polymerization and by tightly anchoring the resulting clot to the underlying wound or to other abnormal vascular surfaces.

Janus Graphene Oxide Sheets with Fe3O4 Nanoparticles and Polydopamine as Anodes for Lithium-Ion Batteries.

In this study, a one-step process to fabricate "Janus"-structured nanocomposites with iron oxide (Fe3O4) nanoparticles (Fe3O4 NPs) and polydopamine (PDA) on each side of a graphene oxide (GO) nanosheet using the Langmuir-Schaefer technique has been proposed. The Fe3O4 NPs-GO hybrid is used as a high-capacity active material, while PDA is added as a binder due to its unique wet-resistant adhesive property. The transmission electron microscopy image shows a superlattice-like out-of-plane section of the multilayered nanocomposite, which maximizes the density of the composite materials. Grazing-incidence small-angle X-ray scattering results combined with scanning electron microscopy images confirm that the multilayered Janus composite exhibits an in-plane hexagonal array structure of closely packed Fe3O4 NPs. This Janus multilayered structure is expected to maximize the amount of active material in a specific volume and reduce volume changes caused by the conversion reaction of Fe3O4 NPs. According to the electrochemical results, the Janus multilayer electrode delivers an excellent capacity of ∼903 mAh g-1 at a current density of 200 mA g-1 and a reversible capacity of ∼639 mAh g-1 at 1 A g-1 up to the 1800th cycle, indicating that this Janus composite can be a promising anode for Li-ion batteries.

Large-Area 2D-MXene Nanosheet Assemblies Using Langmuir-Schaefer Technique: Wrinkle formation.

The formation of uniform sheets of exfoliated MXene over a large area is important for improving their performance in practical applications. In this study, the Langmuir-Schaefer technique was employed to deposit uniform MXene sheets on a solid substrate and control the morphological structure over a large area. At the liquid-gas interface, MXene flakes were densely compressed into nanosheets with minimal gaps between them at 20 mN/m. Through further compression, the wrinkle morphologies of MXene sheets tend to be perpendicularly aligned to the compression direction. These wrinkle structures were also exhibited when MXene sheets were mixed in equal proportions with graphene oxide sheets. Owing to the close correlation of the morphologies of MXene films with the performance of MXene-based materials, the technique employed in this study can provide a route for applications requiring wrinkled MXene, ranging from nanoelectronic devices to energy storage materials, such as supercapacitors and battery electrodes.

3D Printing of Polyethylene Terephthalate Glycol-Sepiolite Composites with Nanoscale Orientation.

A fused-deposition modeling (FDM) 3D-printed polyethylene terephthalate glycol (PETG)-sepiolite composite showed effective synergetic mechanical reinforcement in tensile testing compared to an injection-molded composite. The results showed that the addition of 3 phr sepiolite improved the tensile strength of 3D-printed PETG samples by 35.4%, while the tensile strength of injection-molded PETG samples was improved by 7.2%. To confirm these phenomena, FDM PETG-sepiolite composites were investigated by small-angle X-ray scattering to correlate the nanostructures of the composites with their mechanical strengths. The small-angle X-ray scattering data and transmission electron microscopy observations demonstrated that needle-shaped sepiolite particles were aligned in the printing direction. This fine oriented nanostructure formed during 3D printing created a synergistic effect that improved the material properties of the composite. These novel PETG-sepiolite composites with enhanced mechanical properties can be promising materials fabricated via FDM 3D printing.

Instantaneous integration of magnetite nanoparticles on graphene oxide assisted by ultrasound for efficient heavy metal ion retrieval.

We fabricated a magnetite nanoparticle-graphene oxide (GO) hybrid via a non-chemical and one-step process assisted by ultrasound in an aqueous solution where the nanoparticle attached to the hydrophobic region on graphite oxide (multi-layered GO) which, at the same time, was exfoliated. Unlike chemical methods such as precipitation, oxygen-containing functional groups on GO have not been consumed or reduced during the hybridization, leading that this hybrid exhibited good water solubility and high adsorption capacity for heavy metal ions such as Pb(II) and Au(III). After the adsorption, the hybrid was instantly collected using a magnet. This method can be useful for hybridizing various nanoparticles with GO.

Enhanced Dynamics of Confined Polymers near the Immiscible Polymer-Polymer Interface: Neutron Reflectivity Studies.

For polymer-blend films, local dynamics in confined polymer domains tend to differ from the bulk because of significant contributions from the polymer-polymer interface. Herein, we investigated the diffusion dynamics of entangled polymer thin films confined between different polymers in a direction perpendicular to the surface using neutron reflectivity. We found that a bilayer of poly(methyl methacrylate) (PMMA) and deuterated PMMA (dPMMA) sandwiched between polystyrene (PS) layers exhibited significant increase in mobility near the polymer-polymer interface with decreasing PMMA thickness. This indicates that the contribution of repulsive interactions at the immiscible polymer-polymer interface becomes more significant as the film thickness decreases. We also found that the interfacial roughness between PMMA and PS (28 Å at equilibrium) and soft confinement of PS layers did not significantly affect the change in the diffusion dynamics of the adjacent PMMA. This was evidenced by comparison with the diffusion results of multilayers with a flat interface (8 Å at equilibrium) between PMMA and hard PS by UV cross-linking.

Position-Dependent Diffusion Dynamics of Entangled Polymer Melts Nanoconfined by Parallel Immiscible Polymer Films.

The morphological structure and dynamics of confined polymers adjacent to the polymer-polymer interface have a profound effect on determining the overall physical properties of polymer blends. We measured the diffusion dynamics of poly(methyl methacrylate) (PMMA) melts confined between polystyrene (PS) layers using neutron reflectivity. Combinations of various thicknesses of PMMA and deuterated PMMA (dPMMA) allowed us to experimentally reveal the nonmonotonic behavior of polymer mobility near the PS-PMMA interface. From the neutron reflectivity results, we found that the polymers adjacent to the immiscible polymer-polymer interface showed enhanced diffusion dynamics because of the repulsive interaction between PS and PMMA, whereas the polymer at local regions farther from the interface exhibited reduced dynamics. This is probably due to the nonspherical conformation of PMMA and spatial confinement near the PS-PMMA interface.

Dewetting of Thin Polymer Films on Wrinkled Graphene Oxide Monolayers.

We investigated the effect of the morphological structure of a graphene oxide (GO) monolayer on the dewetting dynamics of the upper polymer thin films. The Langmuir-Schaefer (LS) technique was used to prepare a wrinkled GO ( wrGO) structure with a root mean square (rms) roughness of 22.7 Å. The dewetting behavior of poly(methyl methacrylate) (PMMA) thin films on the wrGO monolayers was perfectly prevented, whereas the PMMA thin films on a flat GO monolayer were dewetted at 203 °C. This wrinkle effect of the GO can be also obtained when the GOs monolayers are intercalated to the PMMA/polystyrene (PS) interface. In this multilayer, the flat GO monolayer at the interface between the PS and PMMA layers was spontaneously roughened with rms roughness of 46.9 Å after annealing and also prohibited the dewetting behavior. From the results, we found that to improve the compatibility of polymer blends by adding the two-dimensional nanosheets, it is important to control the morphological structure of the sheets at the interface, along with manipulation of the GO-polymer interactions.

Free-Standing Janus Graphene Oxide with Anisotropic Properties for 2D Materials as Surfactant.

We present a simple and facile approach to creating asymmetrically modified graphene oxide sheets by grafting polymers with different polarities. Single-layered Janus graphene derivatives were prepared by grafting polymers with different polarities at the liquid-gas interface through one step functionalization. This approach allows obtaining free-standing monolayers of Janus graphene oxide sheets for large area, and also controlling the morphology (i.e., wrinkled Janus graphene oxide sheets) by a compression monolayer. A neutron reflectivity technique is used to check the functionalization on each side of the monolayer, and the results are compared with contact angles to determine its amphiphilic nature. The free-standing Janus monolayers become robust after UV-irradiation, and are able to withstand various solvents. Because these robust Janus graphene films can maintain their anisotropic functionalities over time, this technique provides a new strategy for fabricating functional materials that require amphiphilic properties (i.e., oil-water separation membranes and chemical compatibilizers functioning as a 2D surfactant) and different electrical functionalities (i.e., flexible lightweight p-n junction semiconductors and stimuli-driven actuators).

Spontaneous hybrids of graphene and carbon nanotube arrays at the liquid-gas interface for Li-ion battery anodes.

We demonstrate that hybrid structures of graphene and single-walled carbon nanotubes (SWNTs) are precisely controlled at the liquid-gas interface. The functionalized SWNT Langmuir monolayers anchor single-layer graphene nanosheets (GNSs) suspended in water via Coulomb interaction at the interface. This GNS/SWNT hybrid multilayer electrode can be a promising anode material for Li-ion batteries, offering high specific capacity, outstanding power capability, and excellent cyclability.

Multifaceted Roles of Interleukin-6 in Adipocyte-Breast Cancer Cell Interaction.

Breast cancer is the most common malignancy in women worldwide, with a developmental process spanning decades. The malignant cells recruit a variety of cells including fibroblasts, endothelial cells, immune cells, and adipocytes, creating the tumor microenvironment. The tumor microenvironment has emerged as active participants in breast cancer progression and response to treatment through autocrine and paracrine interaction with the malignant cells. Adipose tissue is abundant in the breast cancer microenvironment; interactions with cancer cells create cancer-associated adipocytes which produce a variety of adipokines that influence breast cancer initiation, metastasis, angiogenesis, and cachexia. Interleukin (IL)-6 has emerged as key compound significantly produced by breast cancer cells and adipocytes, with the potential of inducing proliferation, epithelial-mesenchymal phenotype, stem cell phenotype, angiogenesis, cachexia, and therapeutic resistance in breast cancer cells. Our aim is to present a brief knowledge of IL-6's role in breast cancer. This review summarizes our current understanding of the breast microenvironment, with emphasis on adipocytes as key players in breast cancer tumorigenesis. The effects of key adipocytes such as leptin, adipokines, TGF-b, and IL-6 are discussed. Finally, we discuss the role of IL-6 in various aspects of cancer progression.

Perpendicular Orientation of Diblock Copolymers Induced by Confinement between Graphene Oxide Sheets.

We have studied an orientation structure of self-assembled block copolymers (dPS-b-PMMA) of deuterated polystyrene (dPS) and poly(methyl methacrylate) (PMMA) confined between graphene oxide (GO) surfaces. The results of combination techniques, such as neutron reflectivity, time-of-flight secondary-ion mass spectrometry, grazing-incidence small-angle X-ray scattering, and scanning electron microscopy, show that self-assembled domains of the block copolymers in thin films near the GO sheets are oriented perpendicular to the surface of the GO monolayers, in contrast to the horizontal lamellar structure of the copolymer thin film in the absence of the GO monolayers. This is due to the amphiphilic nature of the GO, which leads to a nonpreferential interaction of both dPS and PMMA blocks. Double-sided confinement with the GO monolayers further extends the ordering behavior of the dPS-b-PMMA thin films. Continuous vertical orientation of the block copolymer thin films is also obtained in the presence of alternating GO layers within thick copolymer films.

The Intraoperative Immunohistochemical Staining of CD56 and CK19 Improves Surgical Decision for Thyroid Follicular Lesions.

BACKGROUND: When differential diagnosis is difficult in thyroid follicular lesions with overlapping histological features, the immunohistochemical staining can help confirm the diagnosis. We aimed to evaluate the effectiveness of rapid immunohistochemical stains of CD56 and cytokeratin 19 on frozen sections of thyroid follicular lesion and explore the possible gains and limitations of the practice. METHODS: Eighty-six nodules of 79 patients whose intraoperative frozen sections were selected as the control group, and 53 nodules of 48 patients whose intraoperative frozen sections were subject to rapid immunohistochemistry were selected as the study group. RESULTS: Five nodules (6%) in the control group were diagnosed as follicular neoplasm and six nodules (7%) were deferred. In the study group, six nodules (11%) were follicular neoplasm and none were deferred. Three nodules (4%) in the control group showed diagnostic discrepancy between the frozen and permanent diagnoses, but none in the study group. The average turnaround time for the frozen diagnosis of the control group was 24 minutes, whereas it was 54 minutes for the study group. CONCLUSIONS: Intraoperative rapid immunohistochemical stains significantly decreased the diagnostic discrepancy in this study. Considering the adverse effects of indefinite frozen diagnosis or discrepancy with permanent diagnoses, the intraoperative rapid immunohistochemical stain can help to accurately diagnose and hence provide guidance to surgical treatment.

Nodal metastasis signatures in breast cancer.

Although the molecular taxonomy of invasive breast cancer is based on heterogeneous histologic types, pathologic nodal (pN) stage remains one of the most important independent prognostic factors. Although node-positive number (NPN) has been widely as an accepted staging algorithm of pN stage, the node-positive ratio (NPR) in totally resected axillary nodes has been considered as another reasonable indicator. We aimed to identify signatures to play a predictive role in nodal metastasis for analytic validation between the primary breast cancers with positive node metastasis and those with negative node metastasis. We validated expression profiles of surrogate candidates extracted from the prior 2D MALDI-TOF data for invasive breast cancer using fluorescence/silver in situ hybridization (FISH/SISH) and immunohistochemistry (IHC) in 151 primary breast cancers accompanied with 102 metastatic nodal tissues. Cox proportional hazards regression analyses indicated that event factors (recurrence or metastasis) were significantly more frequent in cases with CCDN1, c-myc gene amplification, IgHA2 low expression. CCDN1 gene amplification (OR: 5.702, p=0.0006), IgHA2 low expression (OR: 0.16, p=0.0184) remained significant factors for events on multivariate analyses. WDR+/ERK++ was significantly detected in higher pN stage (averaging 6.5 regional nodes or 43% of NPR), while seldom found in pN0-1. In conclusion, both overexpression of WDR1 and p-ERK in the primary breast cancer could play a role in the nodal signature over pN2-3.