Learnable sparse dictionary compressed sensing for channeled spectropolarimeter.

Channeled spectropolarimetry enables real-time measurement of the polarimetric spectral information of the target. A crucial aspect of this technology is the accurate reconstruction of Stokes parameters spectra from the modulated spectra obtained through snapshot measurements. In this paper, a learnable sparse dictionary compressed sensing method is proposed for channeled spectropolarimeter (CSP) spectral reconstruction. Grounded in the compressive sensing framework, this method defines a variable sparse dictionary. It can learn prior knowledge from the measured modulated spectra, continuously optimizing its own structure and parameters iteratively by removing redundant basis functions and refining the matched basis functions. The learned sparse dictionary, post-training, can provide a more accurate sparse representation of the Stokes parameters spectra, enabling the proposed method to achieve more precise reconstruction results. To assess the efficacy of the proposed method, simulations and experiments were conducted, both of which consistently demonstrated the superior performance of the proposed approach. The suggested method is well-positioned to enhance the efficiency and accuracy of polarimetric spectral information retrieval in CSP applications.

Broadband light absorption by a hemispherical concentric nanoshell array.

Achieving highly efficient broadband absorption is an important research area in nanophotonics. In this paper, a novel method is proposed to design broadband near-perfect absorbers, consisting of a four-layer hemispherical concentric nanoshell array. The proposed nanostructure supports absorptivity exceeding 95% in the entire visible region, and the absorption bandwidth is determined by the interaction or 'hybridization' of the plasmons of the inner and outer metal-based nanoshells. Moreover, the designed absorber has wide-angle capability and is insensitive to polarization. The simple structure, as well as the stable absorption properties, suggests that such core-shell nanostructures can serve as a potential candidate for many applications such as solar energy harvesting, photo-detection, and emissivity control.

The potential role of differentially expressed tRNA-derived fragments in high glucose-induced podocytes.

The prevalence of diabetic kidney disease (DKD) is increasing annually. Damage to and loss of podocytes occur early in DKD. tRNA-derived fragments (tRFs), originating from tRNA precursors or mature tRNAs, are associated with various illnesses. In this study, tRFs were identified, and their roles in podocyte injury induced by high-glucose (HG) treatment were explored. High-throughput sequencing of podocytes treated with HG was performed to identify differentially expressed tRFs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed. The expression levels of nephrin, podocin, and desmin were measured in podocytes after overexpression of tRF-1:24-Glu-CTC-1-M2 (tRF-1:24) and concomitant HG treatment. A total of 647 tRFs were identified, and 89 differentially expressed tRFs (|log2FC| ≥ 0.585; p ≤ .05) were identified in the HG group, of which 53 tRFs were downregulated and 36 tRFs were upregulated. The 10 tRFs with the highest differential expression were detected by real-time quantitative polymerase chain reaction (RT-qPCR), and these results were consistent with the sequencing results. GO analysis revealed that the biological process, cellular component, and molecular function terms in which the tRFs were the most enriched were cellular processes, cellular anatomical entities, and binding. KEGG pathway analysis revealed that tRFs may be involved in signaling pathways related to growth hormones, phospholipase D, the regulation of stem cell pluripotency, and T-/B-cell receptors. Overexpression of tRF-1:24, one of the most differentially expressed tRFs, attenuated podocyte injury induced by HG. Thus, tRFs might be potential biomarkers for podocyte injury in DKD.

Schiff base functionalized dialdehyde starch for enhanced removal of Cu (II): Preparation, performances, DFT calculations.

Dialdehyde starch modified by 2-hydrazinopyridine (HYD-DAS) based on the reaction of dialdehyde starch (DAS) and 2-hydrazinopyridine was synthesized and characterized by FT-IR spectra, element analysis and SEM. HYD-DAS can efficiently adsorb Cu (II) ion to demonstrate visual color changes from yellow to dark brown in aqueous solutions. The influence on HYD-DAS to Cu (II) adsorption including pH value of solution, isotherm, kinetics, thermodynamics and possible mechanism had also been examined. Batch experiments indicate that HYD-DAS's to Cu (II) adsorption reaches equilibrium within 250 min, and its adsorption capacity and rate are 195.75 mg/g and 98.63 %, respectively. Moreover, HYD-DAS to Cu (II) adsorption remains robust and underscoring after five cycles to exhibit good selectivity and reusability. Kinetics studies suggest the absorption process follows a quasi-second-order with isotherms aligning to the Langmuir monolayer model, and thermodynamics reveals that it is a spontaneous endothermic nature of adsorption. Based on the analyses of XPS and DFT calculations, a possible mechanism for HYD-DAS to Cu (II) adsorption is that Cu (II) combined with nitrogen atoms from Schiff base and hydrazine pyridine ring in HYD-DAS.

3D hierarchic interfacial assembly of Au nanocage@Au along with IS-AgMNPs for simultaneous, ultrasensitive, reliable, and quantitative SERS detection of colorectal cancer related miRNAs.

Simultaneous, reliable, and ultra-sensitive analysis of promising miRNA biomarkers of colorectal cancer (CRC) in serum is critical for early diagnosis and prognosis of CRC. In this work, we proposed a novel 3D hierarchic assembly clusters-based SERS strategy with dual enrichment and enhancement designed for the ultrasensitive and quantitative analysis of two upregulated CRC-related miRNAs (miR-21 and miR-31). The biosensor contains the following: (1) SERS probe, Au nanocage@Au nanoparticles (AuNC@Au NPs) labeled with Raman reporters (RaRs). (2) magnetic capture unit, Ag-coated Fe3O4 magnetic nanoparticles (AgMNPs) modified with internal standard (IS). (3) signal amplify probes (SA probes) for the formation of hierarchic assembly clusters. Based on this sensing strategy, the intensity ratio IRaRs/IIS with Lg miRNAs presents a wide linear range (10 aM-100 pM) with a limit of detection of 3.46 aM for miR-21, 6.49 aM for miR-31, respectively. Moreover, the biosensor shows good specificity and anti-interference ability, and the reliability and repeatability of the strategy were then verified by practical detection of clinical serum. Finally, the biosensor can distinguish CRC cancer subjects from normal ones and guide the distinct tumor, lymph node, and metastasis (TNM) stages. Overall, benefiting from the face-to-face coupling of hierarchic assembly clusters, rapid magnetic enrichment and IS signal calibration of AgMNPs, the established biosensor achieves ultra-sensitive and simultaneous detection of dual miRNAs and opens potential avenues for prediction and staging of CRC.