An effective cross-scenario remote heart rate estimation network based on global-local information and video transformer.

Remote photoplethysmography (rPPG) technology is a non-contact physiological signal measurement method, characterized by non-invasiveness and ease of use. It has broad application potential in medical health, human factors engineering, and other fields. However, current rPPG technology is highly susceptible to variations in lighting conditions, head pose changes, and partial occlusions, posing significant challenges for its widespread application. In order to improve the accuracy of remote heart rate estimation and enhance model generalization, we propose PulseFormer, a dual-path network based on transformer. By integrating local and global information and utilizing fast and slow paths, PulseFormer effectively captures the temporal variations of key regions and spatial variations of the global area, facilitating the extraction of rPPG feature information while mitigating the impact of background noise variations. Heart rate estimation results on the popular rPPG dataset show that PulseFormer achieves state-of-the-art performance on public datasets. Additionally, we establish a dataset containing facial expressions and synchronized physiological signals in driving scenarios and test the pre-trained model from the public dataset on this collected dataset. The results indicate that PulseFormer exhibits strong generalization capabilities across different data distributions in cross-scenario settings. Therefore, this model is applicable for heart rate estimation of individuals in various scenarios.

Fabrication of tungsten tips with controllable shape by a two-step rapid reciprocating electrochemical etching method.

Traditional electrochemical etching methods for the needle of a liquid metal ion source (LMIS) easily produce an exponential profile with an uncontrollable tip length and apex radius. Meanwhile, a ledge forms between the needle tip and the needle rod under the etching of the meniscus, which becomes an obstacle for the flow and replenishment of the liquid metal. This paper proposed a two-step rapid reciprocating etching method, which aims to fabricate LMIS tungsten needles with controllable tip length and apex radius, and also with a smooth transition region between the needle tip and the needle rod. In the first step of rough machining, the needle rapidly reciprocates up and down in the electrolyte and rotates to produce a uniform conical profile. However, an ellipsoidal residual portion is generated concomitantly at the needle tip. In the second step of finish machining, the needle shifts down for a given distance and continues to reciprocate until the sharp tip is formed. The tip length fabricated varied from 0.59 to 5.53 mm at different reciprocating strokes. The apex radius ranged from 0.3 to 0.7 µm, and can also be increased to 2 µm by extra reciprocate etching in the electrolyte to meet the LMIS working requirement. A variable named transitivity was defined to quantitatively describe the smoothness of the region between the tip and rod during the etching process. The experimental results showed that a rotation speed of 600 rpm combined with a reciprocating speed of 0.5 mm/s can significantly improve the transitivity of the needle. Those fabricated needle tips have been tested for the indium LMIS and the maximum emission current of the needle tip reached 12 µA.

Point-of-care testing of melamine via gas pressure readout using polythymine-coated Au@Pt nanoparticles through specific triple hydrogen-bonding recognition.

The adsorption of single-stranded oligonucleotides (ssDNA) on gold nanoparticles (AuNPs) could stabilize AuNPs against aggregation even at high salt concentrations, and similar phenomena have also been observed on Au core/Pt shell nanoparticles (Au@PtNPs). Inspired by the knowledge that thymine can easily recognize melamine by forming triple H-bonds in aqueous medium, in this contribution, using polythymine-coated Au@PtNPs as the probe, we demonstrated that the responsive aggregation of polyT55 stabilized Au@PtNPs could occur and therefore result in the significant inhibition of the catalysed gas-generation reaction, the decomposition of H2O2 to H2O and O2 catalyzed by Au@PtNPs. Consequently, a pressure-based signaling strategy was developed for highly sensitive and specific melamine detection not only in laboratory but also in point-of-care (POC) settings, and the correlation between the pressure change (ΔP) signal and the melamine concentration was found to be linear from 0.025 to 10.0 µM with a limit of detection of 6.4 nM, providing a convenient new alternative and new train of thought for the specific detection of melamine.

Arabidopsis O-GlcNAc transferase SEC activates histone methyltransferase ATX1 to regulate flowering.

Post-translational modification of proteins by O-linked ß-N-acetylglucosamine (O-GlcNAc) is catalyzed by O-GlcNAc transferases (OGTs). O-GlcNAc modification of proteins regulates multiple important biological processes in metazoans. However, whether protein O-GlcNAcylation is involved in epigenetic processes during plant development is largely unknown. Here, we show that loss of function of SECRET AGENT (SEC), an OGT in Arabidopsis, leads to an early flowering phenotype. This results from reduced histone H3 lysine 4 trimethylation (H3K4me3) of FLOWERING LOCUS C (FLC) locus, which encodes a key negative regulator of flowering. SEC activates ARABIDOPSIS HOMOLOG OF TRITHORAX1 (ATX1), a histone lysine methyltransferase (HKMT), through O-GlcNAc modification to augment ATX1-mediated H3K4me3 histone modification at FLC locus. SEC transfers an O-GlcNAc group on Ser947 of ATX1, which resides in the SET domain, thereby activating ATX1. Taken together, these results uncover a novel post-translational O-GlcNAc modification-mediated mechanism for regulation of HKMT activity and establish the function of O-GlcNAc signaling in epigenetic processes in plants.