PVGAN: A Pathological Voice Generation Model Incorporating a Progressive Nesting Strategy.

The voice generation task is to solve the problem of limited samples in the voice dataset using computer technology. By increasing the number of samples, the accuracy of voice disorder diagnosis can be improved, which has a wide range of application value in medical diagnosis and other fields. At present, there are insufficient models for detailed features such as pitch, timbre, and different frequency components in pathological voice data. Therefore, this paper proposes a PVGAN network for learning different frequency information of audio to generate pathological voice data. The proposed network captures the multi-scale features and different periodic patterns of audio signals by designing multiscale perceptual residual blocks and periodic discriminators. At the same time, a progressive nesting strategy was proposed to combine the generator and the discriminator to improve the learning ability of different resolution information. In addition, a latent mapping network is designed to fuse the latent vector with the condition information to generate sound features related to specific diseases or pathological states. The loss function is optimized to further improve the model performance. On the Saarbruecken Voice Database(SVD), the average values of each index of the data generated after training with different pathological types as conditional information are similar to the original data. Finally, the generated data were used to expand the SVD dataset, and the accuracy of the two classification experiments was improved to a certain extent.

Synthesis of seven-membered lactones by regioselective and stereoselective iodolactonization of electron-deficient olefins.

A regio- and stereoselective iodolactonization of internal electron-deficient olefinic acids has been reported, which provides a straightforward access to a series of multi-functionalized seven-membered lactones containing two consecutive chiral centers. The ester substituents on the olefins played a key role in achieving high regioselectivity. This result was proved through experiments and DFT calculations.

Late-Stage Modification of Tertiary Phosphines via Ruthenium(II)-Catalyzed C-H Alkylation.

Ru(II)-catalyzed direct alkylation of tertiary phosphines via hydroarylation of activated olefins promoted by mono-N-protected amino acid (MPAA) was achieved. This protocol provides a straightforward access to a large library of Buchwald-type bulky alkylated monophosphines from commercially available biaryl phosphine. Moreover, two ruthenacycle intermediates of tertiary phosphines via C-H bond cleavage were isolated to illustrate the mechanism of P(III)-directed C-H activation.