Background: Validated monitoring methods for evaluating the balance of nociception and anti-nociception (BNAN) are needed in general anesthesia. This study assessed six photoplethysmography (PPG) parameters, computed from finger photoplethysmographic waveforms in patients undergoing gynecological surgery under general anesthesia.
Methods: A total of 20 participants were included, each undergoing general anesthesia with propofol and remifentanil. The same concentration of remifentanil was maintained throughout the experiment, four different intensities of electrical stimulation were administered, and the patient's fingertip PPG was meticulously recorded. PPG data were preprocessed to extract six PPG morphological parameters, and photoplethysmographic amplitude (PPGA), pulse beat interval (PBI), and surgical pleth index (SPI). Receiver operating characteristic (ROC) curves and the Area Under the Curve (AUC) were constructed and calculated to accurately measure its ability to reflect the nociceptive stimulus state. The consistency of different phase parameters at different stimulus intensities was evaluated by calculating the prediction probabilities. All results were compared with those obtained using SPI, PPGA, and PBI.
Results: After stimulation, all parameters and SPI showed significant changes compared with those before stimulation (p = 0.000). The catacrotic phase parameters (AC and MHC) showed higher discrimination in adequate analgesia and congruence with electrical stimulation intensity than the overall phase parameters, PPGA, and anacrotic phase parameters (AC: AUC = 0.851, Pk = 0.800; MHC: AUC = 0.837, Pk = 0.792).
Conclusions: In this study, six PPG morphological parameters were proposed and observed for the first time to effectively distinguish the occurrence of nociception. Compared with the overall phase parameters, PPGA, and anacrotic phase parameters, catacrotic phase parameters were more capable of characterizing noxious stimuli and more consistent with changes in electrical stimulation intensity.
Trial Registration: ChiCTR2200062228; Registered at http://clinicaltrials.gov on July 30, 2022.
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http://dx.doi.org/10.1186/s12871-025-02932-3 | DOI Listing |
ACS Appl Mater Interfaces
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State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou 510640, P. R. China.
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March 2025
School of Chemical Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
The self-assemblies of topological complex block copolymers, especially the AB type miktoarm star ones, are fascinating topics in the soft matter field, which represent typical self-assembly behaviors analogous to those of biological membranes. However, their diverse topological asymmetries and versatile spontaneous curvatures result in rather complex phase separations that deviate significantly from the common mechanisms. Thus, numerous trial-and-error experiments with tremendous parameter space and intricate relationships are needed to study their assemblies.
View Article and Find Full Text PDFACS Nano
March 2025
Center for Nanomedicine, Institute for Basic Science (IBS), Seoul 03722, Korea.
Electron beams evolved as important tools for modern technologies that construct and analyze nanoscale architectures. While electron-matter interactions at atomic and macro scales are well-studied, a knowledge gap persists at the molecular to nano level─the scale most relevant to the latest technologies. Here, we employ liquid-phase transmission electron microscopy supported by density functional theory calculations and a mathematical random search algorithm to rationalize and quantify electron beam-induced processes at the molecular level.
View Article and Find Full Text PDFChem Pharm Bull (Tokyo)
March 2025
Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502, Japan.
In the present study, magnetic-calcined bamboo composite adsorbents (MCBC200, MCBC400, MCBC600, MCBC800, and MCBC1000) were prepared, and their physicochemical characteristics (scanning electron microscope images, differential thermogravimetric analysis, Fourier transform-IR, specific surface area, surface functional groups, and point of zero charge [pH]) were evaluated. Furthermore, the adsorption capacity of methylene blue (MB, cationic dye) using the prepared adsorbents was assessed. The value of pH and the specific surface area of MCBC400 were 7.
View Article and Find Full Text PDFJ Chromatogr A
March 2025
Department of Chemistry, University of Memphis, Memphis, TN, 38152, USA. Electronic address:
Polymer liquid chromatography at critical conditions (LCCC) is a chromatographic separation condition achieved by carefully balancing the interaction of a polymer with stationary and mobile phases to make the elution time of a polymer in chromatography independent of its molecular weight. By removing the dependence of elution time on polymer molecular weight, the LCCC then allows separation of polymer samples on the basis of secondary differences, such as topology, branching, and end-group functionality, that are otherwise difficult to resolve. Despite its potential, LCCC remains under-employed due to the complexity of its optimization and the scattered nature of existing data.
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