Risk prediction of pulse wave for hypertensive target organ damage based on frequency-domain feature map.

The application of deep learning to the classification of pulse waves in Traditional Chinese Medicine (TCM) related to hypertensive target organ damage (TOD) is hindered by challenges such as low classification accuracy and inadequate generalization performance. To address these challenges, we introduce a lightweight transfer learning model named MobileNetV2SCP. This model transforms time-domain pulse waves into 36-dimensional frequency-domain waveform feature maps and establishes a dedicated pre-training network based on these maps to enhance the learning capability for small samples. To improve global feature correlation, we incorporate a novel fusion attention mechanism (SAS) into the inverted residual structure, along with the utilization of 3 × 3 convolutional layers and BatchNorm layers to mitigate model overfitting. The proposed model is evaluated using cross-validation results from 805 cases of pulse waves associated with hypertensive TOD. The assessment metrics, including Accuracy (92.74 %), F1-score (91.47 %), and Area Under Curve (AUC) (97.12 %), demonstrate superior classification accuracy and generalization performance compared to various state-of-the-art models. Furthermore, this study investigates the correlations between time-domain and frequency-domain features in pulse waves and their classification in hypertensive TOD. It analyzes key factors influencing pulse wave classification, providing valuable insights for the clinical diagnosis of TOD.

Bifunctionality of dirhodium tetracarboxylates in metallaphotocatalysis.

Metallaphotocatalysis has been recognized as a pivotal catalysis enabling new reactivities. Traditional metallaphotocatalysis often requires two or more separate catalysts and exhibits flaw in cost and substrate-tolerance, thus representing an await-to-solve issue in catalysis. We herein realize metallaphotocatalysis with a bifunctional dirhodium tetracarboxylate ([Rh2]) alone. The [Rh2] shows an photocatalytic activity of promoting singlet oxygen (1O2) oxidation. By harnessing its photocatalytic activity, the [Rh2] catalyzes a photochemical cascade reaction (PCR) via combination of carbenoid chemistry and 1O2 chemistry. The PCR is characterized by high atom-efficiency, excellent stereoselectivities, mild conditions, scalable synthesis, and pharmaceutically interesting products. DFT calculations-aided mechanistic study rationalizes the reaction pathway and interprets the origin of stereoselectivities of the PCR. The products show inhibitory activity against PTP1B, being promising in the treatment of type II diabetes and cancers. Overall, here we show the bifunctional [Rh2] merges Rh-carbenoid chemistry and 1O2 chemistry.

Construction of 4-hydroxycoumarin derivatives with adjacent quaternary and tertiary stereocenters via ternary catalysis.

4-Hydroxycoumarin derivatives represent one of the most important scaffolds in biologically active substances, pharmaceuticals and functional materials. Herein, we describe an efficient Pd/amine/Brønsted acid ternary-catalytic multicomponent reaction for the rapid construction of substituted 4-hydroxycoumarin derivatives with adjacent quaternary and tertiary stereocenters via convergent assembly of two in situ generated active intermediates. Furthermore, the late-stage transformations of coumarin derivatives and their in vitro trial of antitumor activity successfully demonstrated the potential utilities of the products as platform molecules.

Copper-catalyzed multicomponent assembly of γ-butenolides via the interception of carbonyl ylides with iminium ions.

A Cu(I)-catalyzed three-component reaction of cyclopropenes, enamines and aldehydes has been realized. This reaction proceeds via the interception of carbonyl oxonium ylide intermediates with α, ß-unsaturated iminium ions that are in situ generated from enamines and aldehydes under the catalysis of Cu(MeCN)4PF6, leading to the desired γ-butenolide derivatives in good yields and with moderate diastereoselectivities. Access to these derivatives with tethered ketone and alkynal groups will expand the structural diversity of multi-substituted butenolides.

An enantioselective four-component reaction via assembling two reaction intermediates.

A reaction intermediate is a key molecular entity that has been used in explaining how starting materials converts into the final products in the reaction, and it is usually unstable, highly reactive, and short-lived. Extensive efforts have been devoted in identifying and characterizing such species via advanced physico-chemical analytical techniques. As an appealing alternative, trapping experiments are powerful tools in this field. This trapping strategy opens an opportunity to discover multicomponent reactions. In this work, we report various highly diastereoselective and enantioselective four-component reactions (containing alcohols, diazoesters, enamines/indoles and aldehydes) which involve the coupling of in situ generated intermediates (iminium and enol). The reaction conditions presented herein to produce over 100 examples of four-component reaction products proceed under mild reaction conditions and show high functional group tolerance to a broad range of substrates. Based on experimental and computational analyses, a plausible mechanism of this multicomponent reaction is proposed.

Rhodium-Catalyzed Sequential Cycloisomerization/Aldol Addition of Cyclopropene Carboxylic Acids with Isatins.

A unique, rhodium-catalyzed reaction of cyclopropene carboxylic acids with isatins has been developed, which takes place through a trapping process of transient cyclic carboxylic oxonium ylides. This reaction tolerates a wide variety of cyclopropene carboxylic acids and N-protected or unprotected isatins and represents a new, direct strategy to access valuable γ-substituted γ-butenolide architectures containing an oxindole moiety in very high yields under mild reaction conditions.