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No full textBreakdown of long-range spatial correlations of infraslow amplitude fluctuations of EEG oscillations in patients with current and past major depressive disorder
No full textIdentifying biomarkers for depression from brain activity is important for the diagnosis and treatment of depression disorders. We investigated spatial correlations of the amplitude fluctuations of electroencephalography (EEG) oscillations as a potential biomarker of depression. The amplitude fluctuations of EEG oscillations intrinsically reveal both temporal and spatial correlations, indicating rapid and functional organization of the brain networks. Amid these correlations, long-range temporal correlations are reportedly impaired in patients with depression, exhibiting amplitude fluctuations closer to a random process. Based on this occurrence, we hypothesized that the spatial correlations of amplitude fluctuations would also be altered by depression. In the present study, we extracted the amplitude fluctuations of EEG oscillations by filtering them through infraslow frequency band (0.05 ??? 0.1 Hz). We found that the amplitude fluctuations of theta oscillations during eye-closed rest depicted lower levels of spatial correlation in patients with major depressive disorder (MDD) compared to control individuals. This breakdown of spatial correlations was most prominent in the left fronto ??? temporal network, specifically in patients with current MDD rather than in those with past MDD. We also found that the amplitude fluctuations of alpha oscillations during eye-open rest exhibited lower levels of spatial correlation in patients with past MDD compared to control individuals or patients with current MDD. Our results suggest that breakdown of long-range spatial correlations may offer a biomarker for the diagnosis of depression (current MDD), as well as the tracking of the recovery from depression (past MDD)
Impact of catalyst loading of atomically dispersed transition metal catalysts on H2O2 electrosynthesis selectivity
No full textElectrosynthesis of hydrogen peroxide (H2O2) via a two-electron oxygen reduction reaction (2e(-) ORR) has emerged as a promising alternative to the current anthraquinone process. Atomically dispersed transition metal catalysts (M-N/C catalysts; M=transition metal) have received particular attention as H2O2 electrosynthesis catalysts. Among the factors affecting catalytic properties, the catalyst loading on the electrode has significant impacts on the ORR activity and selectivity of M-N/C catalysts in particular and electrocatalysts in general. However, the loading effect has been largely neglected and underexplored in literature. In this study, we investigated the impacts of the catalyst loading and the metal center in M-N/C catalysts on the 2e(-) ORR activity and selectivity. We prepared a series of mesoporous carbons comprising M (Fe, Co, Ni)-based atomically dispersed species, meso-M-N/C catalysts. At a fixed low catalyst loading, the meso-Co-N/C and meso-Ni-N/C catalysts exhibited the best 2e(-)ORR performance under acidic and alkaline electrolytes, respectively. At high catalyst loadings, the H2O2 production activity of the meso-Co-N/C catalyst dramatically declined to similar to 20% compared to that at the low loading. In the thick catalyst layer, the generated H2O2 is accumulated due to poor mass transport, leading to reduction and/or decomposition. In contrast, the H2O2 synthesis activity meso-Ni-N/C catalyst was nearly insensitive to the catalyst loading, which can be ascribed to the high porosity and well -developed mesopores of the meso-Ni-N/C catalyst, promoting mass transport
Nuclear morphology predicts cell survival to cisplatin chemotherapy
No full textThe emergence of chemotherapy resistance drives cancer lethality in cancer patients, with treatment initially reducing overall tumor burden followed by resistant recurrent disease. While molecular mechanisms underlying resistance phenotypes have been explored, less is known about the cell biological characteristics of cancer cells that survive to eventually seed the recurrence. To identify the unique phenotypic characteristics associated with survival upon chemotherapy exposure, we characterized nuclear morphology and function as prostate cancer cells recovered following cisplatin treatment. Cells that survived in the days and weeks after treatment and resisted therapy-induced cell death showed increasing cell size and nuclear size, enabled by continuous endocycling resulting in repeated whole genome doubling. We further found that cells that survive after therapy release were predominantly mononucleated and likely employ more efficient DNA damage repair. Finally, we show that surviving cancer cells exhibit a distinct nucleolar phenotype and increased rRNA levels. These data support a paradigm where soon after therapy release, the treated population mostly contains cells with a high level of widespread and catastrophic DNA damage that leads to apoptosis, while the minority of cells that have successful DDR are more likely to access a pro-survival state. These findings are consistent with accession of the polyaneuploid cancer cell (PACC) state, a recently described mechanism of therapy resistance and tumor recurrence. Our findings demonstrate the fate of cancer cells following cisplatin treatment and define key cell phenotypic characteristics of the PACC state. This work is essential for understanding and, ultimately, targeting cancer resistance and recurrence
Fabricating and Laminating Films with Through-Holes and Engraved/Protruding Structures for 3D Micro/Nanofluidic Platforms
No full textMicro/nanofluidic devices have become popular for delicately processing biological, material, and chemical samples. However, their reliance on 2D fabrication schemes has hindered further innovation. Here, a 3D manufacturing method is proposed through the innovation of laminated object manufacturing (LOM), which involves the selection of building materials as well as the development of molding and lamination techniques. Fabrication of interlayer films is demonstrated with both multi-layered micro-/nanostructures and through-holes, using an injection molding approach and establishing strategic principles of film design. Utilization of the multi-layered through-hole films in LOM allows reducing the number of alignments and laminations by at least two times compared to conventional LOM. Using a dual-curing resin for film fabrication, a surface-treatment-free and collapse-free lamination technique is shown for constructing 3D multiscale micro/nanofluidic devices with ultralow aspect ratio nanochannels. The 3D manufacturing method enables the development of a nanochannel-based attoliter droplet generator capable of 3D parallelization for mass production, which implies the remarkable potential to extend numerous existing 2D micro/nanofluidic platforms into a 3D framework
