473 research outputs found

    Hybrid Functional Study Rationalizes the Simple Cubic Phase of Calcium at High Pressures

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    Simple cubic (SC) phase has been long experimentally determined as the high-pressure phase III of elemental calcium (Ca) since 1984. However, recent density functional calculations within semi-local approximation showed that this SC phase is structurally unstable by exhibiting severely imaginary phonons, and is energetically unstable with respect to a theoretical body-centered tetragonal I41/amd structure over the pressure range of phase III. These calculations generated extensive debates on the validity of SC phase. Here we have re-examined the SC structure by performing more precise density functional calculations within hybrid functionals of Heyd-Scuseria-Erhzerhof (HSE) and PBE0. Our calculations were able to rationalize fundamentally the phase stability of SC structure over all other known phases by evidence of its actual energetic stability above 33 GPa and its intrinsically dynamical stability without showing any imaginary phonons in the entire pressure range studied. We further established that the long-thought theoretical I41/amd structure remains stable in a narrow pressure range before entering SC phase and is actually the structure of experimental Ca-III' synthesized recently at low temperature 14 K as supported by the excellent agreement between our simulated X-ray diffraction patterns and the experimental data. Our results shed strong light on the crucial role played by the precise electron exchange energy in a proper description of the potential energy of Ca.Comment: submitted to Physical Review

    Room-Temperature Structures of Solid Hydrogen at High Pressures

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    By employing first-principles metadynamics simulations, we explore the 300 K structures of solid hydrogen over the pressure range 150-300 GPa. At 200 GPa, we find the ambient-pressure disordered hexagonal close-packed (hcp) phase transited into an insulating partially ordered hcp phase (po-hcp), a mixture of ordered graphene-like H2 layers and the other layers of weakly coupled, disordered H2 molecules. Within this phase, hydrogen remains in paired states with creation of shorter intra-molecular bonds, which are responsible for the very high experimental Raman peak above 4000 cm-1. At 275 GPa, our simulations predicted a transformation from po-hcp into the ordered molecular metallic Cmca phase (4 molecules/cell) that was previously proposed to be stable only above 400 GPa. Gibbs free energy calculations at 300 K confirmed the energetic stabilities of the po-hcp and metallic Cmca phases over all known structures at 220-242 GPa and >242 GPa, respectively. Our simulations highlighted the major role played by temperature in tuning the phase stabilities and provided theoretical support for claimed metallization of solid hydrogen below 300 GPa at 300 K.Comment: Accepted in Journal of Chemical Physic

    Analysis of Demographic Characteristics and Psychological Factors of Opioid Addicts in Zhengzhou Area

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    Objective: To explore the demographic characteristics and psychological factors of patients with opioid addiction. Methods: A random number method was used to select 200 opioid-addicted patients admitted to the 7th People’s Hospital of Zhengzhou from January 2019 to February 2020. Demographic characteristics and psychosocial factors were analyzed. Result: The proportion of opioid addicts aged 21 ~ 30 was the highest; the proportion of men was significantly higher; the proportion of people who is between jobs/unemployed is the highest; the proportion of junior middle school was the highest, and the proportion of unmarried was relatively high; the proportion of opioid addicts with ignorance/curiosity for the cause of first addiction was the highest; the use of suction is snorting, accounting for the highest proportion. According to the analysis of relevant social and psychological factors, the proportion of single parent family group is the highest, the proportion of parent tension is the highest, and the proportion of bad life coping style is relatively high. At the same time, dependent psychology occupies the highest proportion in psychological factors of relapse patients. Conclusion: By analyzing the demographic characteristics of opioid addicts and the psychosocial factors of their addiction, we can strengthen prevention and management for specific groups to reduce the new addition and relapse of opioid addicts

    2-(2-Iodo­phen­yl)-1,2,3,4-tetra­hydro­isoquinoline-1-carbonitrile

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    In the title compound, C16H13IN2, the two benzene rings make a dihedral angle of 67.26 (5)°. The six-membered heterocycle of the tetra­hydro­isoquinoline unit adopts a half-chair conformation. In the crystal, adjacent mol­ecules are linked by pairs of weak inter­molecular C—H⋯N hydrogen bonds, forming inversion dimers. An intra­molecular C—H⋯I close contact is also observed

    Secretory Leukocyte Protease Inhibitor Binds to Annexin II, a Cofactor for Macrophage HIV-1 Infection

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    The distribution of secretory leukocyte protease inhibitor (SLPI) at entry portals indicates its involvement in defending the host from pathogens, consistent with the ability of SLPI to inhibit human immunodeficiency virus (HIV)-1 infection by an unknown mechanism. We now demonstrate that SLPI binds to the membrane of human macrophages through the phospholipid-binding protein, annexin II. Based on the recent identification of human cell membrane phosphatidylserine (PS) in the outer coat of HIV-1, we define a novel role for annexin II, a PS-binding moiety, as a cellular cofactor supporting macrophage HIV-1 infection. Moreover, this HIV-1 PS interaction with annexin II can be disrupted by SLPI or other annexin II–specific inhibitors. The PS–annexin II connection may represent a new target to prevent HIV-1 infection

    Intelligent Knee Sleeves: A Real-time Multimodal Dataset for 3D Lower Body Motion Estimation Using Smart Textile

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    The kinematics of human movements and locomotion are closely linked to the activation and contractions of muscles. To investigate this, we present a multimodal dataset with benchmarks collected using a novel pair of Intelligent Knee Sleeves (Texavie MarsWear Knee Sleeves) for human pose estimation. Our system utilizes synchronized datasets that comprise time-series data from the Knee Sleeves and the corresponding ground truth labels from the visualized motion capture camera system. We employ these to generate 3D human models solely based on the wearable data of individuals performing different activities. We demonstrate the effectiveness of this camera-free system and machine learning algorithms in the assessment of various movements and exercises, including extension to unseen exercises and individuals. The results show an average error of 7.21 degrees across all eight lower body joints when compared to the ground truth, indicating the effectiveness and reliability of the Knee Sleeve system for the prediction of different lower body joints beyond the knees. The results enable human pose estimation in a seamless manner without being limited by visual occlusion or the field of view of cameras. Our results show the potential of multimodal wearable sensing in a variety of applications from home fitness to sports, healthcare, and physical rehabilitation focusing on pose and movement estimation.Comment: Accepted by Thirty-seventh Conference on Neural Information Processing Systems (Neurips) D&B Trac

    Immunomodulatory effects of complex probiotics on the immuno-suppressed mice induced by cyclophosphamide

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    IntroductionPrevious studies have reported the beneficial effects of Bifidobacterium animalis subsp. lactis XLTG11, Lacticaseibacillus casei Zhang, and Lactiplantibacillus plantarum P8, respectively. However, studies on the immunomodulatory enhancing effects of three complex probiotics have not been conducted. The aim of our study is to investigate the immunomodulatory effects of complex probiotics effect on the immunosuppressed mice induced by cyclophosphamide (CTX).MethodsAn immunocompromised mouse model was established by intraperitoneal injection of cyclophosphamide, which was gavage of different doses of complex probiotics and levamisole hydrochloride. The splenic and thymic indices, intestinal barrier, leukocyte and lymphocyte counts, percentage of splenic lymphocyte subpopulations, cytokine levels, and gut microbiota were determined.ResultsResults showed that the complex probiotics significantly elevated the spleen and thymus indices, increased the villi and crypt depth and the goblet cells. The leukocyte and lymphocyte counts and the percentage of splenic lymphocyte subpopulations in the CTX-treated mice were significantly elevated by the complex probiotics. In addition, the cytokines (IL-6, IL-10, IL-1β, and IFN-γ) were significantly increased after complex probiotic treatment. The complex probiotics restored the gut microbiota structure to the pattern of the control group by reducing the ratio of Firmicutes/Bacteroidetes and enhancing the relative abundances of specific microbiota that produced short-chain fatty acids.DiscussionThis study provides theoretical support for the immunity-enhancing function of the complex probiotics as well as a pharmacological basis for its further development and utilization

    The Functions of Effector Proteins in Yersinia Virulence

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    Yersinia species are bacterial pathogens that can cause plague and intestinal diseases after invading into human cells through the Three Secre­tion System (TTSS). The effect of pathogenesis is mediated by Yersinia outer proteins (Yop) and manifested as down-regulation of the cytokine genes expression by inhibiting nuclear factor-κ-gene binding (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. In addition, its pathogenesis can also manipulate the disorder of host innate immune system and cell death such as apoptosis, pyroptosis, and autophagy. Among the Yersinia effector proteins, YopB and YopD assist the injection of other virulence effectors into the host cytoplasm, while YopE, YopH, YopJ, YopO, and YopT target on disrupting host cell signaling pathways in the host cytosols. Many efforts have been applied to reveal that intracellular proteins such as Rho-GTPase, and transmembrane receptors such as Toll-like receptors (TLRs) both play critical roles in Yersinia pathogenesis, establishing a connection between the pathogenic process and the signaling response. This review will mainly focus on how the effector proteins of Yersinia modulate the intrinsic signals in host cells and disturb the innate immunity of hosts through TTSS

    Detecting cell types and densities in the tumor microenvironment improves prognostic risk assessment for breast cancer

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    A comprehensive evaluation of the relationship between the densities of various cell types in the breast cancer tumor microenvironment and patient prognosis is currently lacking. Additionally, the absence of a large patch-level whole slide imaging (WSI) dataset of breast cancer with annotated cell types hinders the ability of artificial intelligence to evaluate cell density in breast cancer WSI. We first employed Lasso-Cox regression to build a breast cancer prognosis assessment model based on cell density in a population study. Pathology experts manually annotated a dataset containing over 70,000 patches and used transfer learning based on ResNet152 to develop an artificial intelligence model for identifying different cell types in these patches. The results showed that significant prognostic differences were observed among breast cancer patients stratified by cell density score (P = 0.0018), with the cell density score identified as an independent prognostic factor for breast cancer patients (P < 0.05). In the validation cohort, the predictive performance for overall survival (OS) was satisfactory, with area under the curve (AUC) values of 0.893 (OS) at 1-year, 0.823 (OS) at 3-year, and 0.861 (OS) at 5-year intervals. We trained a robust model based on ResNet152, achieving over 99% classification accuracy for different cell types in patches. These achievements offer new public resources and tools for personalized treatment and prognosis assessment
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