Gut microbiome: A potential indicator for predicting treatment outcomes in major depressive disorder

The therapeutic outcomes in major depressive disorder (MDD), one of the most common and heterogeneous mental illnesses, are affected by factors that remain unclear and often yield unsatisfactory results. Herein, we characterized the composition and metabolic function of the gut microbiota of patients with MDD during antidepressant treatment, based on 16S rRNA sequencing and metabolomics. The microbial signatures at baseline differed significantly between responder and non-responder groups. The gut microbiota of the non-responder group was mainly characterized by increased relative abundances of the phylum Actinobacteria, families Christensenellaceae and Eggerthellaceae, and genera Adlercreutzia and Christensenellaceae R7 group compared to that of the responder group. Additionally, the gut microbiota composition of the responder and non-responder groups differed significantly before and after treatment, especially at the genus level. Moreover, 20 differential metabolites between the responder and non-responder groups were identified that were mainly involved in lipid metabolism (cholestane steroids and steroid esters). Eggerthellaceae and Adlercreutzia displayed strong co-occurrence relationships with certain metabolites, suggesting alternations in the gut microbiome, and associated metabolites may be potential mediators of successful antidepressant treatment. Overall, our study demonstrates that alterations in gut microbiota composition and metabolic function might be relevant to the response to antidepressants, thereby providing insight into mechanisms responsible for their efficacy

Preparation of atomic-layer transition metal chalcogenides with application in opto-electronic devices

Graphene like two-dimensional materials are important elements of potential optoelectronics applications due to their exceptional electronic and optical properties. The preparation and processing of these materials towards the realization of opto-electronic devices has been one of the main motivations for the recent development of photonics and optoelectronics. My Ph.D projects involves with three aspects: 1. Preparations of atomic-layer transition metal dichalcogenides (TMDs), e.g. MoS₂ , WS₂ and WSe₂ with chemical vapour depositions. In this part, we present the synthesis of large size (>100 μm) single crystals of atomically thin tungsten disulfide (WS₂ ), a member of TMDs family, on sapphire substrate. More importantly, we demonstrate a polystyrene (PS) mediated delamination process via capillary force in water which allows recyclable use of the growth substrates; 2. Fabrication of TMDs based photodetectors and study the performance and mechanisms with spatial photocurrent mapping. We developed an efficient photodetector with extremely large photo-responsive active area based on a lateral p-n junction of monolayer-bilayer WSe₂ . The junction is produced by partially peeling off the upper layer of a bilayer WSe₂ crystal grown by atmospheric pressure chemical vapour deposition. Kelvin probe force microscope and photocurrent mapping were used to understand the performance and the mechanism; 3. Atomic layered thin TMDs based flat lenses: fabrication and imaging. An ultrathin flat lens with a thickness of 7 Å, which corresponds to the fundamental physical limit of material thickness, is fabricated on a large monolayer WSe2 single crystals with direct femtosecond laser writing. We apply the material with ultra-high refractive index to achieve three-dimensional (3D) focusing with almost diffraction-limited resolution by effective modulation of the amplitude of the incident light

Photonics and Optoelectronics of Low-Dimensional Materials

201812 bcrcVersion of RecordPublishe