Structural brain feature is associated with changes of masticatory performance in healthy elderly people: Evidence from longitudinal neuroimaging research over two years.

BACKGROUND: Human neuroimaging studies have revealed the association between brain structure and masticatory function. However, the majority of the studies adopted a cross-sectional design, which hardly reveals the change in masticatory function and brain structure between different timepoints, and the dynamical association between changes in masticatory function and changes in brain structure has not been elucidated. OBJECTIVE: With a longitudinal design, we assessed the association between changes in masticatory performance (MP) and regional brain volume. METHODS: Twenty-two elderly participants received assessments of the number of missing teeth and MP (via colour-changeable chewing gum) when they entered the study (i.e. the initial stage, T0 ), approximately 6 months later (T0.5 ), and approximately 1-2 years later (T1 ). Difficulty of food intake was assessed using a questionnaire. The participants received magnetic resonance imaging (MRI) at T0 and T1 . The brain volume of the motor-related area was estimated using FreeSurfer for MRI data. The associations between different stages were analysed using Spearman's rho correlation coefficients. RESULTS: (1) Individually, a smaller volume of right primary motor cortex at T0 was associated with increased MP from T0 to T1 , suggesting the brain's role in changing oral functions; (2) higher MP at T0 was associated with an increased volume of the left superior frontal cortex from T0 to T1 p, suggesting a potential effect on brain plasticity, and (3) increased difficulty to eat was associated with decrease MP but not brain volume of motor-related area. CONCLUSIONS: The preliminary findings revealed a complicated pattern of structural brain features and masticatory function in elderly people, and either the hypothesis that the brain predisposes masticatory function or the hypothesis that mastication reshapes the brain is oversimplified.

Spatiotemporal gating of Stat nuclear influx by Drosophila Npas4 in collective cell migration.

Collective migration is important to embryonic development and cancer metastasis, but migratory and nonmigratory cell fate discrimination by differential activity of signal pathways remains elusive. In Drosophila oogenesis, Jak/Stat signaling patterns the epithelial cell fates in early egg chambers but later renders motility to clustered border cells. How Jak/Stat signal spatiotemporally switches static epithelia to motile cells is largely unknown. We report that a nuclear protein, Dysfusion, resides on the inner nuclear membrane and interacts with importin α/ß and Nup153 to modulate Jak/Stat signal by attenuating Stat nuclear import. Dysfusion is ubiquitously expressed in oogenesis but specifically down-regulated in border cells when migrating. Increase of nuclear Stat by Dysfusion down-regulation triggers invasive cell behavior and maintains persistent motility. Mammalian homolog of Dysfusion (NPAS4) also negatively regulates the nuclear accumulation of STAT3 and cancer cell migration. Thus, our finding demonstrates that Dysfusion-dependent gating mechanism is conserved and may serve as a therapeutic target for Stat-mediated cancer metastasis.

Hierarchical Structures, with Submillimeter Patterns, Micrometer Wrinkles, and Nanoscale Decorations, Suppress Biofouling and Enable Rapid Droplet Digitization.

Liquid repellant surfaces have been shown to play a vital role for eliminating thrombosis on medical devices, minimizing blood contamination on common surfaces as well as preventing non-specific adhesion. Herein, an all solution-based, easily scalable method for producing liquid repellant flexible films, fabricated through nanoparticle deposition and heat-induced thin film wrinkling that suppress blood adhesion, and clot formation is reported. Furthermore, superhydrophobic and hydrophilic surfaces are combined onto the same substrate using a facile streamlined process. The patterned superhydrophobic/hydrophilic surfaces show selective digitization of droplets from various solutions with a single solution dipping step, which provides a route for rapid compartmentalization of solutions into virtual wells needed for high-throughput assays. This rapid solution digitization approach is demonstrated for detection of Interleukin 6. The developed liquid repellant surfaces are expected to find a wide range of applications in high-throughput assays and blood contacting medical devices.

Flexible Hierarchical Wraps Repel Drug-Resistant Gram-Negative and Positive Bacteria.

Healthcare acquired infections are a major human health problem, and are becoming increasingly troublesome with the emergence of drug resistant bacteria. Engineered surfaces that reduce the adhesion, proliferation, and spread of bacteria have promise as a mean of preventing infections and reducing the use of antibiotics. To address this need, we created a flexible plastic wrap that combines a hierarchical wrinkled structure with chemical functionalization to reduce bacterial adhesion, biofilm formation, and the transfer of bacteria through an intermediate surface. These hierarchical wraps were effective for reducing biofilm formation of World Health Organization-designated priority pathogens Gram positive methicillin-resistant Staphylococcus aureus (MRSA) and Gram negative Pseudomonas aeruginosa by 87 and 84%, respectively. In addition, these surfaces remain free of bacteria after being touched by a contaminated surface with Gram negative E. coli. We showed that these properties are the result of broad liquid repellency of the engineered surfaces and the presence of reduced anchor points for bacterial adhesion on the hierarchical structure. Such wraps are fabricated using scalable bottom-up techniques and form an effective cover on a variety of complex objects, making them superior to top-down and substrate-specific surface modification methods.

Correction: Solution-processed wrinkled electrodes enable the development of stretchable electrochemical biosensors.

Correction for 'Solution-processed wrinkled electrodes enable the development of stretchable electrochemical biosensors' by Yuting Chan et al., Analyst, 2019, 144, 172-179.

Liquid Cell Transmission Electron Microscopy Sheds Light on The Mechanism of Palladium Electrodeposition.

Electrodeposition is widely used to fabricate tunable nanostructured materials in applications ranging from biosensing to energy conversion. A model based on 3D island growth is widely accepted in the explanation of the initial stages of nucleation and growth in electrodeposition. However, there are regions in the electrodeposition parameter space where this model becomes inapplicable. We use liquid cell transmission electron microscopy along with post situ scanning electron microscopy to investigate electrodeposition in this parameter space, focusing on the effect of the supporting electrolyte, and to shed light on the nucleation and growth of palladium. Using a collection of electron microscopy images and current time transients recorded during electrodeposition, we discover that electrochemical aggregative growth, rather than 3D island growth, best describes the electrodeposition process. We then use this model to explain the change in the morphology of palladium electrodeposits from spherical to open clusters with nonspherical morphology when HCl is added to the electrolyte solution. The enhanced understanding of the early stages of palladium nucleation and growth and the role of electrolyte in this process provides a systematic route toward the electrochemical fabrication of nanostructured materials.

Solution-processed wrinkled electrodes enable the development of stretchable electrochemical biosensors.

Wearable biosensors are critical for enabling real-time and continuous health monitoring and disease management. Conductors that retain their conductivity under strain are an essential building block of these systems. Strategies based on stretchable materials or structures have enabled the development of electrodes that can withstand impressive strains before loss of conductivity. In spite of this, it remains challenging to develop three-dimensional and high surface area electrodes that combine stretchability with high analytical sensitivity. Here, we develop stretchable electrochemical biosensors using solution-processed wrinkled gold electrodes. Wrinkling enhances the surface area of the electrodes and allows glucose to be detected with a sensitivity of 750-810 µA M-1 cm-2. Furthermore, wrinkling enables electrodes to be strained by up to 230% without significant loss in conductivity.

Enhancing the Photoelectrochemical Response of DNA Biosensors Using Wrinkled Interfaces.

Photoelectrochemical (PEC) biosensors, with optical biasing and electrochemical readout, are expected to enhance the limit-of-detection of electrochemical biosensors by lowering their background signals. However, when PEC transducers are functionalized with biorecognition layers, their current significantly decreases, which reduces their signal-to-noise ratio and dynamic range. Here, we develop and investigate a wrinkled conductive scaffold for loading photoactive quantum dots into an electrode. The wrinkled photoelectrodes demonstrate an order of magnitude enhancement in the magnitude of the transduced PEC current compared to their planar counterparts. We engineer PEC biosensors by functionalizing the wrinkled photoelectrodes with nucleic acid capture probes. We challenge the sensitivity of the wrinkled and planar biosensors with various concentrations of DNA target and observe a 200 times enhancement in the limit-of-detection for wrinkled versus planar electrodes. In addition to enhanced sensitivity, the wrinkled PEC biosensors are capable of distinguishing between fully complementary and targets with a single base-pair mismatch, demonstrating the suitability of these biosensors for use in clinical diagnostics.