Ultrasensitive and multiplexed Gastric cancer biomarkers detection with an integrated electrochemical immunosensing platform.

Developing immunosensing platforms capable of simultaneously detecting multiple cancer markers is crucial for clinical diagnosis and biomedical research. Here, we introduce a novel dual-mode electrochemical biosensing assay platform capable of detecting two gastric cancer biomarkers: pepsinogen I (PG I) and pepsinogen II (PG II). Methylene blue (MB) and Prussian blue (PB) were used as dual signal sources to label PG I and PG II, respectively.

Application of Directed Evolution and Machine Learning to Enhance the Diastereoselectivity of Ketoreductase for Dihydrotetrabenazine Synthesis.

Biocatalysis is an effective approach for producing chiral drug intermediates that are often difficult to synthesize using traditional chemical methods. A time-efficient strategy is required to accelerate the directed evolution process to achieve the desired enzyme function. In this research, we evaluated machine learning-assisted directed evolution as a potential approach for enzyme engineering, using a moderately diastereoselective ketoreductase library as a model system.

Asymmetric Synthesis of β-Hydroxyphosphonates via a Chemoenzymatic Cascade.

Chiral β-hydroxyphosphonates are essential building blocks for organophosphorus compounds. However, the asymmetric synthesis of these units remains a significant challenge. Herein, we describe a one-pot chemoenzymatic cascade process to access chiral β-hydroxyphosphonates, which combines photo-oxidative chemical reactions and bioreductions.

Surface Flashover Induced by Metal Contaminants Adhered to Tri-Post Epoxy Insulators under Superimposed Direct and Lightning Impulse Voltages.

Metal contaminants can distort the surface electric field of the tri-post epoxy insulator and cause serious surface charge accumulation, significantly reducing the insulation performance of the insulator under the superimposed DC and lightning impulse voltage. In this paper, an experimental platform for charge accumulation and surface flashover of tri-post epoxy insulators under the superimposed DC and lightning impulse voltage was built, by surface point measurement and charge inversion calculation, the surface charge distribution characteristics of tri-post insulators with attached particles was experimentally explored and the influence law of attached metal particles on the charge accumulation was discussed. The results show that metal particles can cause a surge in the surface charge density of the tri-post epoxy insulator, forming bipolar charge spots whose polarity is opposite to that of the adjacent electrodes.

Frequency and Temperature-Dependent Space Charge Characteristics of a Solid Polymer under Unipolar Electrical Stresses of Different Waveforms.

In this paper, we studied the space charge phenomena of a solid polymer under thermal and electrical stresses with different frequencies and waveforms. By analyzing the parameter selection method of a protection capacitor and resistor, the newly built pulsed electro-acoustic (PEA) system can be used for special electrical stresses under 500 Hz, based on which the charge phenomena are studied in detail under positive and negative DC and half-wave sine and rectangular wave voltages. Experimental results show that the charge accumulated in the polyimide polymer under DC conditions mainly comes from the grounded electrode side, and the amount of charge accumulated with electric field distortion becomes larger in a high-temperature environment.