The Potential of Aptamer-Mediated Liquid Biopsy for Early Detection of Cancer

The early detection of cancer favors a greater chance of curative treatment and long-term survival. Exciting new technologies have been developed that can help to catch the disease early. Liquid biopsy is a promising non-invasive tool to detect cancer, even at an early stage, as well as to continuously monitor disease progression and treatment efficacy. Various methods have been implemented to isolate and purify bio-analytes in liquid biopsy specimens. Aptamers are short oligonucleotides consisting of either DNA or RNA that are capable of binding to target molecules with high specificity. Due to their unique properties, they are considered promising recognition ligands for the early detection of cancer by liquid biopsy. A variety of circulating targets have been isolated with high affinity and specificity by facile modification and affinity regulation of the aptamers. In this review, we discuss recent progress in aptamer-mediated liquid biopsy for cancer detection, its associated challenges, and its future potential for clinical applications.     

Charge injection and decay of nanoscale dielectric films resolved via dynamic scanning probe microscopy

To satisfy continual demands for higher performance dielectrics in multi-layer ceramic capacitors and related microelectronic devices, novel characterization methods are necessary for mapping materials properties down to the nanoscale, where enabling materials developments are increasingly relevant. Accordingly, an atomic force microscopy-based approach is implemented for characterizing insulator performance based on the mapping of discharging dynamics. Following surface charging by biasing a conducting tip contacting a dielectric surface, consecutive non-contact Kelvin force surface potential mapping (KPFM) reveals charge dissipation via exponential decay. In barium titanate (BTO) thin films engineered with distinct microstructures but identical thicknesses, discharging rates vary by up to a factor of 2, with smaller grain size correlating to longer dissipation times, providing insight into optimal microstructures for improved capacitor performance. High-resolution potential mapping as a function of time thereby provides a route for directly investigating charge injection and discharging mechanisms in dielectrics, which are increasingly engineered down to the nanoscale and have global implications given the trillions of such devices manufactured each year.     

Understanding the Role of Alumina (Al2O3), Pentalithium Aluminate (Li5AlO4), and Pentasodium Aluminate (Na5AlO4) Coatings on the Li and Mn-Rich NCM Cathode Material 0.33Li2MnO3·0.67Li(Ni0.4Co0.2Mn0.4)O2 for Enhanced Electrochemical Performance

The active role of alumina, pentalithium aluminate (Li₅AlO₄, Li-aluminate), and pentasodium aluminate (Na₅AlO₄, Na-aluminate) as the surface protection coatings produced via atomic layer deposition on Li and Mn-rich NCM cathode materials 0.33Li₂MnO₃·0.67LiNi_0.4Co_0.2Mn_0.4O₂ is discussed. A notable improvement in the electrochemical behavior of the coated cathodes has been found while tested in Li-coin cells at 30 °C. Though all the coated cathodes demonstrate enhanced electrochemical cycling and rate performances, Na-aluminate coated cathodes exhibit exemplary behavior. Prolonged cycling and rate capability testing demonstrate that after more than 400 cycles at 1 C rate, the uncoated cathode delivers only 63 mAh g⁻¹, while those with alumina, Li-aluminate, and Na-aluminate coatings exhibit approximately two times higher specific capacities. The coated cathodes display steady average discharge potential and lower evolution of the voltage hysteresis during prolonged cycling compared to the uncoated cathode. Importantly, Na-aluminate coated cathode shows a lowering in gases (O₂, CO₂, H₂, etc.) evolution. Post-cycling analysis of the electrodes demonstrates higher morphological integrity of the coated cathode materials and lower transition metals dissolution from them. The coatings mitigate undesirable side reactions between the electrodes and the electrolyte solution in the cells.     

Engineering a Highly Active Sucrose Isomerase for Enhanced Product Specificity by Using a “Battleship” Strategy

The sucrose isomerase SmuA from Serratia plymuthica efficiently catalyses the isomerisation of sucrose into isomaltulose, an artificial sweetener used in the food industry. However, the formation of a hygroscopic by-product, trehalulose, necessitates additional separation to obtain a crystalline product. Therefore, we have improved the product specificity of SmuA by first introducing a few exploratory amino acid exchanges around the active site and investigating their influence. Then, we devised a second set of mutations, either at promising positions from the preceding cycle, but with a different side chain, or at alternative positions in the vicinity. After seven iterative cycles involving just 55 point mutations, we obtained the triple mutant Y219L/D398G/V465E which showed 2.3 times less trehalulose production but still had high catalytic efficiency (k_cat/K_M=11.8 mM⁻¹ s⁻¹). Not only does this mutant SmuA appear attractive as an industrial biocatalyst, but our semirational protein-engineering strategy, which resembles the battleship board game, should be of interest for other challenging enzyme optimization endeavours.     

Influence of the viscosity of poly(methyl methacrylate) on the cellular structure of nanocellular materials

Three different grades of poly(methyl methacrylate) (PMMA) with different rheological properties are used for the production of nanocellular materials using gas dissolution foaming. The influences of both the viscosity of the different polymers and the processing parameters on the final cellular structure are studied using a wide range of saturation and foaming conditions. Foaming conditions affect similarly all cellular materials. It is found that an increase of the foaming temperature results in less dense nanocellular materials, with higher cell nucleation densities. In addition, it is demonstrated that a lower viscosity leads to cellular polymers with a lower relative density but larger cell sizes and smaller cell nucleation densities, these differences being more noticeable for the conditions in which low solubilities are reached. It is possible to produce nanocellular materials with relative densities of 0.24 combined with cell sizes of 75 nm and cell nucleation densities of 10¹⁵ nuclei cm^?3 using the PMMA with the lowest viscosity. In contrast, minimum cell sizes of around 14 nm and maximum cell nucleation densities of 3.5 × 10¹⁶ nuclei cm^?3 with relative densities of 0.4 are obtained with the most viscous one. © 2019 Society of Chemical Industry     

Hybrid bacterial cellulose-collagen membranes production in culture media enriched with antioxidant compounds from plant extracts

Bioactive, structural, and mechanical properties were measured of a cellulose biopolymer produced by Gluconacetobacter xylinus using hydrolyzed collagen and phenolic compounds from teas and grape pomace (GP) in an optimized culture medium. Biopolymers were impregnated with an antibiotic to investigate possible antibacterial activities. Hybrid bacterial cellulose (BC)-collagen membranes obtained from cultures with green tea and a ternary mixture (TM) of teas with GP presented a high concentration of phenolic compounds (879.7 and 1312.8 mg gallic acid equivalent per liter) and antioxidant activity (973.3 and 575.9 mmol/g), respectively. BC membranes included a nanodimensional network of microfibrils, and the addition of hydrolyzed collagen in the TM of teas in situ resulted in thicker structures with improved mechanical properties. BC-collagen membranes pretreated with cephalexin exhibited significant inhibition against Escherichia coli and Staphylococcus aureus. The enrichment of the culture media with plant phenolic compounds and collagen resulted in the formation of hybrid BC membranes in a shorter time when compared to those produced without these components. Membranes modified with bioactive compounds in situ and antibiotics ex situ can be turned into potential products for application in biomaterials with antioxidant activity.     

Atomic‐Scale Control of Electronic Structure and Ferromagnetic Insulating State in Perovskite Oxide Superlattices by Long‐Range Tuning of BO6 Octahedra

Control of BO₆ octahedral rotations at the heterointerfaces of dissimilar ABO₃ perovskites has emerged as a powerful route for engineering novel physical properties. However, its impact length scale is constrained at 2–6 unit cells close to the interface and the octahedral rotations relax quickly into bulk tilt angles away from interface. Here, a long‐range (up to 12 unit cells) suppression of MnO₆ octahedral rotations in La_0.9Ba_0.1MnO₃ through the formation of superlattices with SrTiO₃ can be achieved. The suppressed MnO₆ octahedral rotations strongly modify the magnetic and electronic properties of La_0.9Ba_0.1MnO₃ and hence create a new ferromagnetic insulating state with enhanced Curie temperature of 235 K. The emergent properties in La_0.9Ba_0.1MnO₃ arise from a preferential occupation of the out‐of‐plane Mn d_3z²_?r² orbital and a reduced Mn e_g bandwidth, induced by the suppressed octahedral rotations. The realization of long‐range tuning of BO₆ octahedra via superlattices can be applicable to other strongly correlated perovskites for exploring new emergent quantum phenomena.     

Dialogic intervisualizing in multimodal inquiry

International Journal of Computer-Supported Collaborative Learning - Problem-based learning (PBL) designs are addressing the demands and potentials of an information-saturated era where accessing...     

Non-substituted fused bis-tetracene based thin-film transistor with self-assembled monolayer hybrid dielectrics

Polycyclic aromatic hydrocarbons with zigzag peripheries are high perspective candidates for organic electronics. However, large fused acenes are still poorly studied due to the tedious synthesis. Herein we report a non-substituted fused bistetracene DBATT (2.3,8.9-dibenzanthanthrene) as the semiconductor on low-voltage-driven organic thin-film transistors. The systematic studies of thin-film growth on various self-assembled monolayer (SAM) modified gate dielectrics and the electrical performances were carried out. The sub-monolayer of the semiconductor film shows larger island domains on the alkyl chain SAM. This device exhibits the hole mobility of 0.011 cm²·V⁻¹·s⁻¹ with a current ratio of I_on/I_off above 10⁵.