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171.
Fabrício RS Pereira Andréa Alessio Maurício S Sercheli Tatiane Pedro Elizabeth Bilevicius Jane M Rondina Helka FB Ozelo Gabriela Castellano Roberto JM Covolan Benito P Damasceno Fernando Cendes 《BMC neuroscience》2010,11(1):1-13
Background
Recent studies have shown that the human right-hemispheric auditory cortex is particularly sensitive to reduction in sound quality, with an increase in distortion resulting in an amplification of the auditory N1m response measured in the magnetoencephalography (MEG). Here, we examined whether this sensitivity is specific to the processing of acoustic properties of speech or whether it can be observed also in the processing of sounds with a simple spectral structure. We degraded speech stimuli (vowel /a/), complex non-speech stimuli (a composite of five sinusoidals), and sinusoidal tones by decreasing the amplitude resolution of the signal waveform. The amplitude resolution was impoverished by reducing the number of bits to represent the signal samples. Auditory evoked magnetic fields (AEFs) were measured in the left and right hemisphere of sixteen healthy subjects.Results
We found that the AEF amplitudes increased significantly with stimulus distortion for all stimulus types, which indicates that the right-hemispheric N1m sensitivity is not related exclusively to degradation of acoustic properties of speech. In addition, the P1m and P2m responses were amplified with increasing distortion similarly in both hemispheres. The AEF latencies were not systematically affected by the distortion.Conclusions
We propose that the increased activity of AEFs reflects cortical processing of acoustic properties common to both speech and non-speech stimuli. More specifically, the enhancement is most likely caused by spectral changes brought about by the decrease of amplitude resolution, in particular the introduction of periodic, signal-dependent distortion to the original sound. Converging evidence suggests that the observed AEF amplification could reflect cortical sensitivity to periodic sounds. 相似文献172.
173.
Dr. Yanbang Li Rohin Biswas William P. Kopcha Dr. Thierry Dubroca Dr. Laura Abella Yue Sun Ryan A. Crichton Dr. Christopher Rathnam Dr. Letao Yang Dr. Yao-Wen Yeh Dr. Krishnendu Kundu Dr. Antonio Rodríguez-Fortea Prof. Josep M. Poblet Prof. Ki-Bum Lee Prof. Stephen Hill Dr. Jianyuan Zhang 《Angewandte Chemie (International ed. in English)》2023,62(3):e202380362
174.
175.
Dr. Yanbang Li Rohin Biswas William P. Kopcha Dr. Thierry Dubroca Dr. Laura Abella Yue Sun Ryan A. Crichton Dr. Christopher Rathnam Dr. Letao Yang Dr. Yao-Wen Yeh Dr. Krishnendu Kundu Dr. Antonio Rodríguez-Fortea Prof. Josep M. Poblet Prof. Ki-Bum Lee Prof. Stephen Hill Dr. Jianyuan Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(3):e202211704
Endohedral metallofullerenes (EMFs) are excellent carriers of rare-earth element (REE) ions in biomedical applications because they preclude the release of toxic metal ions. However, existing approaches to synthesize water-soluble EMF derivatives yield mixtures that inhibit precise drug design. Here we report the synthesis of metallobuckytrio (MBT), a three-buckyball system, as a modular platform to develop structurally defined water-soluble EMF derivatives with ligands by choice. Demonstrated with PEG ligands, the resulting water-soluble MBTs show superb biocompatibility. The Gd MBTs exhibit superior T1 relaxivity than typical Gd complexes, potentially superseding current clinical MRI contrast agents in both safety and efficiency. The Lu MBTs generated reactive oxygen species upon light irradiation, showing promise as photosensitizers. With their modular nature to incorporate other ligands, we anticipate the MBT platform to open new paths towards bio-specific REE drugs. 相似文献