2,239 research outputs found
Different phase leads to different transport behavior in PbCu(PO)O compounds
The recent claimed room-temperature superconductivity in Cu-doped lead
apatite at ambient pressure are under highly debate. To identify its physical
origin, we studied the crystal structures, energy band structures, lattice
dynamics and magnetic properties of the parent Pb(PO)O compound,
in which two different phases of the LK-99 compound are analyzed in detail. Our
results show that the Pb(PO)O compound is an indirect band gap
semiconductor, where Cu doping at the 4 site of Pb leads to a semiconducting
to half-metallic transition. Two half-filled flat bands spanning the Fermi
energy levels are present in the 4-phase of LK-99, which are mainly formed
by hybridization of the and orbitals of Cu with the 2
orbitals of O. In addition, 6-phase of LK-99 always has spin polarity at the
bottom of the conduction band and at the top of the valence band, making the
material a bipolar magnetic semiconductor. Our results are basically consistent
with the recent experimental transport properties of LK-99 posted on
arXiv:2308.05778.Comment: 6 pages and 4 figure
Absorption, Distribution and Excretion of 14C-Probimane in Mice Bearing Lewis Lung Carcinoma
Spontaneous neoplasm metastasis, a fatalist pathological feature of cancer, is a long-evolving, multi-steps process that can now only be treated or controlled by drugs or immuno-modulators. Probimane (Pro), as a representative of the well-known class of antimetastatic agents ‘Bisdioxopiperazine compounds (Biz)’, is systematically studied for its absorption, distribution and excretion in mice bearing Lewis lung carcinoma by a radioactivity-detective method in this investigation. It is found that the 14C-Pro concentrations in different normal organs of mice at 2 hrs are very high and dramatically declined at 24 and 48 hrs. However, Pro concentrations in metastatic foci are slightly changed at the same time. Almost no change of Pro concentrations is observed in pulmonary metastatic nodules within 48 hrs. This evidence can be used to explain the characteristics of good metastatic inhibition by Biz compounds. The radioactivity in brain is relatively low because Pro can hardly penetrate into the blood-brain-barrier to eliminate brain tumors. The excretion of 14C-Pro is observed at the same ratios from both urine and feces and also at constant rates. These data are much useful for better understanding of the general pharmacological characters and possible antimetastatic mechanisms of actions of probimane and other Biz compounds from a new perspective and research angles
Different Spontaneous Pulmonary Metastasis Inhibitions against Lewis Lung Carcinoma in Mice by Bisdioxopiperazine Compounds of Different Treatment Schedules
Spontaneous neoplasm metastasis, a fatalist pathological feature of cancer, is a long-evolving, multi-steps process that can now only be treated or controlled by drugs or immuno-modulators. As we have previously hypothesized, each drug or immuno-modulator might act differently within various stages of a metastasis. Therefore any researches helping to determine these differences will be beneficial for updating therapeutics for metastasis. In this work, we have testified this hypothesis by using a series of well-known anti-metastatic agents – Bisdioxopiperazine compounds
Seeing through the Brain: Image Reconstruction of Visual Perception from Human Brain Signals
Seeing is believing, however, the underlying mechanism of how human visual
perceptions are intertwined with our cognitions is still a mystery. Thanks to
the recent advances in both neuroscience and artificial intelligence, we have
been able to record the visually evoked brain activities and mimic the visual
perception ability through computational approaches. In this paper, we pay
attention to visual stimuli reconstruction by reconstructing the observed
images based on portably accessible brain signals, i.e., electroencephalography
(EEG) data. Since EEG signals are dynamic in the time-series format and are
notorious to be noisy, processing and extracting useful information requires
more dedicated efforts; In this paper, we propose a comprehensive pipeline,
named NeuroImagen, for reconstructing visual stimuli images from EEG signals.
Specifically, we incorporate a novel multi-level perceptual information
decoding to draw multi-grained outputs from the given EEG data. A latent
diffusion model will then leverage the extracted information to reconstruct the
high-resolution visual stimuli images. The experimental results have
illustrated the effectiveness of image reconstruction and superior quantitative
performance of our proposed method.Comment: A preprint version of an ongoing wor
ON and OFF retinal ganglion cells differentially regulate serotonergic and GABAergic activity in the dorsal raphe nucleus
The dorsal raphe nucleus (DRN), the major source of serotonergic input to the forebrain, receives excitatory input from the retina that can modulate serotonin levels and depressive-like behavior. In the Mongolian gerbil, retinal ganglion cells (RGCs) with alpha-like morphological and Y-like physiological properties innervate the DRN with ON DRN-projecting RGCs out numbering OFF DRN-projecting RGCs. The DRN neurons targeted by ON and OFF RGCs are unknown. To explore retino-raphe anatomical organization, retinal afferents labeled with Cholera toxin B were examined for association with the postsynaptic protein PSD-95. Synaptic associations between retinal afferents and DRN serotonergic and GABAergic neurons were observed. To explore retino-raphe functional organization, light-evoked c-fos expression was examined. Light significantly increased the number of DRN serotonergic and GABAergic cells expressing c-Fos. When ON RGCs were rendered silent while enhancing the firing rate of OFF RGCs, c-Fos expression was greatly increased in DRN serotonergic neurons suggesting that OFF DRN-projecting RGCs predominately activate serotonergic neurons whereas ON DRN-projecting RGCs mainly target GABAergic neurons. Direct glutamatergic retinal input to DRN 5-HT neurons contributes to the complex excitatory drive regulating these cells. Light, via the retinoraphe pathway can modify DRN 5-HT neuron activity which may play a role in modulating affective behavior
ATACgraph: Profiling genome-wide chromatin accessibility from ATAC-seq
Assay for transposase-accessible chromatin using sequencing data (ATAC-seq) is an efficient and precise method for revealing chromatin accessibility across the genome. Most of the current ATAC-seq tools follow chromatin immunoprecipitation sequencing (ChIP-seq) strategies that do not consider ATAC-seq-specific properties. To incorporate specific ATAC-seq quality control and the underlying biology of chromatin accessibility, we developed a bioinformatics software named ATACgraph for analyzing and visualizing ATAC-seq data. ATACgraph profiles accessible chromatin regions and provides ATAC-seq-specific information including definitions of nucleosome-free regions (NFRs) and nucleosome-occupied regions. ATACgraph also allows identification of differentially accessible regions between two ATAC-seq datasets. ATACgraph incorporates the docker image with the Galaxy platform to provide an intuitive user experience via the graphical interface. Without tedious installation processes on a local machine or cloud, users can analyze data through activated websites using pre-designed workflows or customized pipelines composed of ATACgraph modules. Overall, ATACgraph is an effective tool designed for ATAC-seq for biologists with minimal bioinformatics knowledge to analyze chromatin accessibility. ATACgraph can be run on any ATAC-seq data with no limit to specific genomes. As validation, we demonstrated ATACgraph on human genome to showcase its functions for ATAC-seq interpretation. This software is publicly accessible and can be downloaded at https://github.com/RitataLU/ATACgraph
How does stakeholder engagement through environmental, social, and governance affect eco-efficiency and profitability efficiency? Zooming into Apple Inc.'s counterparts
As global ecological degradation intensifies, a trade-off has arisen between environmental protection and production efficiency to achieve sustainable development for the environment, society, and the company itself. However, the potential reverse causality relationship between environmental, social, and governance (ESG) and corporate efficiency may lead to confusion. This study estimates the eco-efficiency of Apple Incorporated's value-chain counterparts in the first stage and creates values and profitability in the second stage of efficiency evaluation. Results obtained from the (i) directional distance function in the two-stage data envelopment analysis (DEA), (ii) additive efficiency decomposition two-stage network DEA model, and (iii) network slacks-based measure model are consistent. That is, Apple counterparts manage more efficient eco-efficiency than profitability efficiency, implying that eco-efficiency is their competitive advantage. We thus also run a regression analysis to examine how the ESG ratings of Apple counterparts explain their eco-efficiency and profitability efficiency. Although the overall ESG rating positively explains the efficiencies, we found that the individual governance rating shows no statistically significant effect. The regression results provide insight for practitioners on the importance of investing in the three aspects of a firm's collective conscientiousness for societal and environmental governance. This paper integrates companies' eco-efficiency and profitability efficiency to resolve the conflict between environmental issues and production efficiency. It also analyzes in depth the effects of ESG and its three individual factors on eco-, profitability, and average efficiencies. The diversity of research methods also provides new ideas for future research related to firm efficiency
Nonlinear effects of ESG on energy-adjusted firm efficiency: Evidence from the stakeholder engagement of apple incorporated
This study examines how the (i) overall environmental, social, and governance (OESG) performance; (ii) three individual E, S, and G (IESG) performance; and (iii) subcomponents of the three individual E, S, and G (SIESG) performance affect 29 Apple Incorporation partners' energy-adjusted firm efficiency from a nonlinear perspective. Our truncated regression findings from 145 firm-year observations for the period of 2016–2020 indicate that the association between OESG performance and energy-adjusted firm efficiency is U-shaped. However, this nonlinear U-shape exists in the individual S and G but not E of the IESG performance. Moreover, only certain subcomponents of the SIESG performance are nonlinearly related to energy-adjusted firm efficiency. Overall, we highlight both the costs and benefits of the ESG performance for maintaining sustainable development and stakeholder engagement. The energy-adjusted firm efficiency estimated through the multidimensional data envelopment analysis approach is also noteworthy for policy and decision-making purposes
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