Ultrasensitive colorimetric detection of creatinine via its dual binding affinity for silver nanoparticles and silver ions.

Creatinine is an important biomarker for the diagnosis of chronic kidney disease (CKD). Recently, it has been reported that the concentration of salivary creatinine correlates well with the concentration of serum creatinine, which makes the former useful for the development of non-invasive and point-of-care (POC) detection for CKD diagnosis. However, there exists a technical challenge in the rapid detection of salivary creatinine at low concentrations of 3-18 µM when using the current kidney function test strips as well as the traditional methods employed in hospitals. Herein, we demonstrate a simple, sensitive colorimetric assay for the detection of creatinine with a limit-of-detection (LOD) down to the nanomolar level. Our approach utilises the dual binding affinity of creatinine for citrate-capped silver nanoparticles (Ag NPs) and Ag(i) ions, which can trigger the aggregation of Ag NPs and thus lead to the colour change of a sample. The quantitative detection of creatinine was achieved using UV-Vis spectroscopy with a LOD of 6.9 nM in artificial saliva and a linear dynamic range of 0.01-0.06 µM. This method holds promise to be further developed into a POC platform for the CKD diagnosis.

Toward Fabrication of Devices Based on Graphene/Oxide Multilayers.

Owing to its high electrical conductivity, low density, and flexibility, graphene has great potential for use as a building block in a wide range of applications from nanoelectronics to biosensing and high-frequency devices. For many device applications, it is required to deposit dielectric materials on graphene at high temperatures and in ambient oxygen. This has been proven to be highly challenging because these conditions cause significant degradation in graphene. In this work, we investigate the degradation of graphene at elevated temperatures in an oxygen atmosphere and possible protection mechanisms to enable the growth of oxide thin films on graphene at higher temperatures. We show that coating graphene with self-assembled monolayers of hexamethyldisilazane (HMDS) prior to a high-temperature deposition can significantly reduce the damage induced. Furthermore, a graphene sample treated with HMDS displayed a weaker doping effect due to weak interaction with oxygen species than bare graphene, and a much slower rate of electrical resistance degradation was exhibited during annealing. Thus, it is a promising approach that could enable the deposition of metal oxide materials on graphene at high temperatures without significant degradation in graphene quality, which is critical for a wide range of applications.

Encapsulating Ni Nanoparticles into Interlayers of Nitrogen-Doped Nb2 CTx MXene to Boost Hydrogen Evolution Reaction in Acid.

Design and development of low-cost and highly efficient non-precious metal electrocatalysts for hydrogen evolution reaction (HER) in an acidic medium are key issues to realize the commercialization of proton exchange membrane water electrolyzers. Ni is regarded as an ideal alternative to substitute Pt for HER based on the similar electronic structure and low price as well. However, low intrinsic activity and poor stability in acid restrict its practical applications. Herein, a new approach is reported to encapsulate Ni nanoparticles (NPs) into interlayer edges of N-doped Nb2 CTx MXene (Ni NPs@N-Nb2 CTx ) by an electrochemical process. The as-prepared Ni NPs@N-Nb2 CTx possesses Pt-like onset potentials and can reach 500 mA cm-2 at overpotentials of only 383 mV, which is much higher than that of N-Nb2 CTx supported Ni NPs synthesized by a wet-chemical method (w- Ni NPs/N-Nb2 CTx ). Furthermore, it shows high durability toward HER with a large current density of 300 mA cm-2 for 24 h because of the encapsulated structure against corrosion, oxidation as well as aggregation of Ni NPs in an acidic medium. Detailed structural characterization and density functional theory calculations reveal that the stronger interaction boosts the HER.

Analysis of the Correlation between College Music Education and Public Mental Health Based on Deep Learning.

With the continuous changes of college music education and public mental health problems, conventional solutions are no longer sufficient. At this time, we adopted a method based on deep learning to study them. The experiments showed that ① deep learning can be well integrated into two. Among them, the rapport rate between them reached 91%, and the sometimes-unstable state of the system was solved by optimizing the model. Finally, through the evaluation algorithm, the overall score of the model was obtained to fluctuate between 85 and 90. ② According to the data in the figures and tables, it can be concluded that university music education under deep learning has received more attention in my country, and the investment amount has also increased from 2.4 billion to 3.7 billion. The highest music education activities in universities have become 55% of concerts and 41% of musical instrument experience classes, and finally, my country's public mental health problem has become a country with the lowest level in the world.

Tuning Electronic Structures of Transition Metal Carbides to Boost Oxygen Evolution Reactions in Acidic Medium.

Developing low-cost, efficient, and robust nonprecious metal electrocatalysts for oxygen evolution reactions (OER) in acidic medium is the major challenge to realize the application of the proton exchange membrane water electrolyzer (PEM-WE). It is well-known that transition metal carbides (TMCs) have Pt-like electronic structures and catalytic behaviors. However, monometallic carbides in acidic medium show ignored OER activities. Herein, we reported that the catalytic activity of the TMCs can be enhanced by constructing bimetallic carbides (TiTaC2) fabricated through hydrothermal treatment followed by an annealing process, and further by doping fluorine (F) into the bimetallic carbides (TiTaFxC2). The as-prepared reduced graphene oxide (rGO) supported TiTaFxC2 nanoparticles (TiTaFxC2 NP/rGO) show state-of-the-art OER catalytic activity, which is even superior to Ir/C catalyst (an onset potential of only 1.42 V vs RHE and the overpotential of 490 mV to reach 100 mA cm-2), fast kinetics (Tafel slope of only 36 mV dec-1), and high durability (maintaining the current density at 1.60 V vs RHE for 40 h). Detailed structural characterizations together with density functional theory (DFT) calculations reveal that the electronic structures of the bimetallic carbides have been tuned, and their possible mechanism is also discussed.

Knockdown of cell division cycle-associated protein 4 expression inhibits proliferation of triple negative breast cancer MDA-MB-231 cells in vitro and in vivo.

Cell division cycle-associated protein 4 (CDCA4), also known as SEI-3/hematopoietic progenitor protein, is a target gene of transcription factor E2F and represses E2F-dependent transcriptional activation and cell proliferation. The present study investigated the effects of CDCA4 knockdown on the regulation of triple negative breast cancer (TNBC) cell proliferation in vitro and in vivo. Human TNBC MDA-MB-231 cells were subjected to CDCA4 expression knockdown using a lentiviral vector carrying CDCA4 or a negative control short hairpin RNA, and reverse transcription-quantitative polymerase chain reaction, MTT cell viability, cell growth, flow cytometric apoptosis, cell cycle and nude mouse tumorigenesis assays were conducted. The knockdown of CDCA4 expression effectively inhibited the growth of MDA-MB-231 cells by promoting apoptosis in vitro. Additionally, CDCA4 expression knockdown suppressed nude mouse tumor cell xenograft formation and growth in vivo. In conclusion, the data from the present study supported the hypothesis that CDCA4 may be involved in regulating human TNBC progression, and that targeting CDCA4 expression could be useful as a novel strategy in future TNBC treatment.