Surface Functionalized Titanium Nitride Electrode for CMOS Compatible Bioelectronic Devices.

The development of bioelectronic devices is heading toward high throughput and high resolution. Yet, most electrode materials utilized in electrical biosensing are not compatible with the manufacturing techniques of semiconductor chips, which somehow hinders the integration and miniaturization of these devices. Titanium nitride (TiN) is a durable and economical material that is widely used in CMOS-based integrated circuits, bioelectronic systems, electrocatalytic systems, etc. Considering different application scenarios, new and efficient methods are required to functionalize TiN surface. In this study, a surface functionalization approach by covalent grafting of an organic thin film containing hydroxyl groups on TiN surface via electroreduction of diazonium salt 4-(2-hydroxyethyl)benzenediazonium was presented. Cyclic voltammetry (CV) procedures were carried out at the potential ranges of -0.8 V~0.5 V (vs Ag/AgCl) with varying numbers of potential cycles (i. e., 5, 25, and 50 cycles) in order to study the thickness of modification layer. Then, the electrochemical property, surface morphology, and chemical structures of the sample before and after modifications were investigated via multiple characterization techniques, such as CV, atomic force microscopy (AFM), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS), etc., thereby confirming the successful grafting of hydroxyl groups onto the TiN surface. The experiments on DNA synthesis aimed to explore the potential of modified TiN electrode as a novel platform for DNA data storage applications and the corresponding proof-of-principle was accomplished by the process of coupling Cy3-phosphoramidite. Finally, the experiments were successfully reproduced on the randomly selected sites of the modified TiN microarray chips demonstrating the potential of technical protocol to extend applications in future bioelectronic devices, such as bio-sensing, high-throughput DNA synthesis, and molecular manipulation.

Spatial Release From Masking With Bilateral Bone Conduction Stimulation at Mastoid for Normal Hearing Subjects.

This study investigates the effect of spatial release from masking (SRM) in bilateral bone conduction (BC) stimulation at the mastoid. Nine adults with normal hearing were tested to determine SRM based on speech recognition thresholds (SRTs) in simulated spatial configurations ranging from 0 to 180 degrees. These configurations were based on nonindividualized head-related transfer functions. The participants were subjected to sound stimulation through either air conduction (AC) via headphones or BC. The results indicated that both the angular separation between the target and the masker, and the modality of sound stimulation, significantly influenced speech recognition performance. As the angular separation between the target and the masker increased up to 150°, both BC and AC SRTs decreased, indicating improved performance. However, performance slightly deteriorated when the angular separation exceeded 150°. For spatial separations less than 75°, BC stimulation provided greater spatial benefits than AC, although this difference was not statistically significant. For separations greater than 75°, AC stimulation offered significantly more spatial benefits than BC. When speech and noise originated from the same side of the head, the "better ear effect" did not significantly contribute to SRM. However, when speech and noise were located on opposite sides of the head, this effect became dominant in SRM.

High-throughput DNA synthesis for data storage.

With the explosion of digital world, the dramatically increasing data volume is expected to reach 175 ZB (1 ZB = 1012 GB) in 2025. Storing such huge global data would consume tons of resources. Fortunately, it has been found that the deoxyribonucleic acid (DNA) molecule is the most compact and durable information storage medium in the world so far. Its high coding density and long-term preservation properties make itself one of the best data storage carriers for the future. High-throughput DNA synthesis is a key technology for "DNA data storage", which encodes binary data stream (0/1) into quaternary long DNA sequences consisting of four bases (A/G/C/T). In this review, the workflow of DNA data storage and the basic methods of artificial DNA synthesis technology are outlined first. Then, the technical characteristics of different synthesis methods and the state-of-the-art of representative commercial companies, with a primary focus on silicon chip microarray-based synthesis and novel enzymatic DNA synthesis are presented. Finally, the recent status of DNA storage and new opportunities for future development in the field of high-throughput, large-scale DNA synthesis technology are summarized.

The impact of career calling on nurse burnout: A moderated mediation model.

AIM: To evaluate the mediating roles of occupational resilience and the moderationg role of perceived organizational support in the relationship between career calling and nurse burnout. BACKGROUND: Burnout is a frequent and serious problem in the field of nursing, and it poses a serious threat to both nurses' health and patient safety. Although many studies have described the links between burnout, career calling, and occupational resilience, little is known about the actual mechanisms between career calling and nurse burnout. METHODS: A cross-sectional study of 615 nurses in China was conducted using a convenience sampling method. The data were analyzed using descriptive statistics and Pearson correlation analysis. Hypotheses were tested using structural equation models and bootstrapping methods. STROBE guidelines were followed. RESULTS: Career calling was found to be negatively associated with nurse burnout, and occupational resilience mediated the relationship between career calling and burnout. Additionally, perceived organizational support was found to play a moderating role in the relationship between occupational resilience and burnout. CONCLUSION: Career calling can reduce burnout by increasing nurses' levels of occupational resilience, and perceived organizational support moderates this mechanism. Hence, policies focused on encouraging and sustaining career calling should be provided by nurse managers in order to enhance stress resistance and reduce burnout.

Fe-codoped carbon dots serving as a peroxidase mimic to generate in situ hydrogen peroxide for the visual detection of glucose.

Nanozyme technology has gained significant regard and been successfully implemented in various applications including chemical sensing, bio-medicine, and environmental monitoring. Fe-CDs were synthesized and characterized well in this study. As compared to HRP (3.7 mM), the Fe-CDs exhibited a higher affinity towards H2O2 (0.2 mM) using the steady-state kinetic assay and stronger catalytic capability by changing the color of TMB to the blue color of the oxidized state, oxTMB. Additionally, an efficient peroxidase mimic, Fe-CDs/GOx, based on the hybrid cascade system to produce in situ H2O2 for the visual detection of glucose (color change: colorless to blue, and then to green), has been developed in detail, with limits of detection (LODs) for H2O2 and glucose of 0.33 µM and 1.17 µM, respectively. The changes further demonstrate a linear relationship between absorbance and H2O2 concentration, ranging from 10 to 60 µM, and for glucose (1 to 60 µM). To assess the accuracy and detection capability of the Fe-CDs/GOx system, we evaluated a real human serum sample obtained from adult males in a local hospital. In conclusion, Fe-CDs serving as a peroxidase mimic have the potential for various applications in the fields of biomedicine and nanozymes.

Back Injection Molding of Sub-Micron Scale Structures on Roll-to-Roll Extrusion Coated Films.

Roll-to-roll extrusion coated films were bonded onto polymer parts by back injection molding (BIM). The polypropylene (PP) coated polyethylene terephthalate (PET) films were pre-patterned with microstructured V-shaped grooves with 3.2 µm and 53 µm width, and other geometries. Bonding on PET and poly(methyl methacrylate) (PMMA) parts was facilitated by either higher tool or melt temperatures but was particularly enhanced by applying a mild oxygen plasma to the backside of the PET film prior to injection of the polymer melt. Silver wires from conductive nanoparticle ink were embedded into the PP coating during the BIM process by controlled collapse of the V-grooves. Thus, the feasibility of combining standard carrier film materials for printed flexible electronics and packaging into a non-flat polymer part was demonstrated, which could be a helpful step towards the fabrication of polymer parts with surface functionality.

Nanogroove-Enhanced Hydrogel Scaffolds for 3D Neuronal Cell Culture: An Easy Access Brain-on-Chip Model.

In order to better understand the brain and brain diseases, in vitro human brain models need to include not only a chemically and physically relevant microenvironment, but also structural network complexity. This complexity reflects the hierarchical architecture in brain tissue. Here, a method has been developed that adds complexity to a 3D cell culture by means of nanogrooved substrates. SH-SY5Y cells were grown on these nanogrooved substrates and covered with Matrigel, a hydrogel. To quantitatively analyze network behavior in 2D neuronal cell cultures, we previously developed an automated image-based screening method. We first investigated if this method was applicable to 3D primary rat brain cortical (CTX) cell cultures. Since the method was successfully applied to these pilot data, a proof of principle in a reductionist human brain cell model was attempted, using the SH-SY5Y cell line. The results showed that these cells also create an aligned network in the 3D microenvironment by maintaining a certain degree of guidance by the nanogrooved topography in the z-direction. These results indicate that nanogrooves enhance the structural complexity of 3D neuronal cell cultures for both CTX and human SH-SY5Y cultures, providing a basis for further development of an easy access brain-on-chip model.

Validation and Optimization of an Image-Based Screening Method Applied to the Study of Neuronal Processes on Nanogrooves.

Research on neuronal differentiation and neuronal network guidance induced through nanotopographical cues generates large datasets, and therefore the analysis of such data can be aided by automatable, unbiased image screening tools. To link such tools, we present an image-based screening method to evaluate the influence of nanogroove pattern dimensions on neuronal differentiation. This new method consists of combining neuronal feature detection software, here HCA-Vision, and a Frangi vesselness algorithm to calculate neurite alignment values and quantify morphological aspects of neurons, which are measured via neurite length, neuronal polarity, and neurite branching, for differentiated SH-SY5Y cells cultured on nanogrooved polydimethylsiloxane (PDMS) patterns in the 200-2000 nm range. The applicability of this method is confirmed by our results, which find that the level of alignment is dependent on nanogroove dimensions. Furthermore, the screening method reveals that differentiation and alignment are correlated. In particular, patterns with groove widths >200 nm and with a low ridge width to pattern period ratio have a quantifiable influence on alignment, neurite length, and polarity. In summary, the novel combination of software that forms a base for this statistical analysis method demonstrates good potential for evaluating tissue microarchitecture, which depends on subtle design variation in substrate topography. Using the screening method, we obtained automated and sensitive quantified readouts from large datasets.

Matrix protein biglycan induces osteoblast differentiation through extracellular signal-regulated kinase and Smad pathways.

Biglycan (Bgn) is a member of the small leucine-rich proteoglycan (SLRP) family found in bone extracellular matrix (ECM), and hence involved in regulating bone formation and matrix mineralization. It has been reported that Bgn facilitates osteoblast differentiation, and extracellular signal-regulated kinase (Erk) and Smad are two important pathways in regulating osteoblast differentiation. However, the underlying mechanism for Bgn facilitating osteoblast differentiation has not been fully elucidated. The present study demonstrated that the matrix protein Bgn activates Erk signaling pathway and therefore increases Runx2 transcriptional activity, in which glycosaminoglycans (GAGs) chains play an essential role. Additionally, Bgn also activated Smad pathway, another signaling pathway related with osteoblast differentiation. The activation of these two signaling pathways induced by Bgn facilitated the mineralization deposition in vitro. These results demonstrated the mechanism of Bgn promoting osteoblast differentiation and matrix mineralization.