38 research outputs found

    Research progress on graphene and its derivatives modulating the bone regeneration microenvironment

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    Graphene family nanomaterials (GFNs) are highly popular in the field of bone tissue engineering because of their excellent mechanical properties, biocompatibility, and ability to promote the osteogenic differentiation of stem cells. GFNs play a multifaceted role in promoting the bone regeneration microenvironment. First, GFNs activate the adhesion kinase/extracellularly regulated protein kinase (FAK/ERK) signaling pathway through their own micromorphology and promote the expression of osteogenesis-related genes. Second, GFNs adapt to the mechanical strength of bone tissue, which helps to maintain osseointegration; by adjusting the stiffness of the extracellular matrix, they transmit the mechanical signals of the matrix to the intracellular space with the help of focal adhesions (FAs), thus creating a favorable physiochemical microenvironment. Moreover, they regulate the immune microenvironment at the site of bone defects, thus directing the polarization of macrophages to the M2 type and influencing the secretion of relevant cytokines. GFNs also act as slow-release carriers of bioactive molecules with both angiogenic and antibacterial abilities, thus accelerating the repair process of bone defects. Multiple types of GFNs regulate the bone regeneration microenvironment, including scaffold materials, hydrogels, biofilms, and implantable coatings. Although GFNs have attracted much attention in the field of bone tissue engineering, their application in bone tissue regeneration is still in the basic experimental stage. To promote the clinical application of GFNs, there is a need to provide more sufficient evidence of their biocompatibility, elucidate the mechanism by which they induce the osteogenic differentiation of stem cells, and develop more effective form of applications

    A pilot study of a group mindfulness-based cognitive-behavioral intervention for smartphone addiction among university students

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    Background and aims: Mindfulness-based intervention (MBI) has been applied in behavioral addiction studies in recent years. However, few empirical studies using MBI have been conducted for smartphone addiction, which is prevalent among Chinese university students. The aim of this study was to investigate the effectiveness of a group mindfulness-based cognitive-behavioral intervention (GMCI) on smartphone addiction in a sample of Chinese university students. Methods: Students with smartphone addiction were divided into a control group (n = 29) and an intervention group (n = 41). The students in the intervention group received an 8-week GMCI. Smartphone addiction was evaluated using scores from the Mobile Phone Internet Addiction Scale (MPIAS) and self-reported smartphone use time, which were measured at the baseline (1st week, T1), post-intervention (8th week, T2), the first follow-up (14th week, T3), and the second follow-up (20th week, T4). Results: Twenty-seven students in each group completed the intervention and the follow-up. Smartphone use time and MPIAS scores significantly decreased from T1 to T3 in the intervention group. Compared with the control group, the intervention group had significantly less smartphone use time at T2, T3, and T4 and significantly lower MPIAS scores at T3. Discussion and conclusion: This pilot study demonstrated that the GMCI could significantly alleviate smartphone addiction among university students

    Pre-nuclear values for I-129/I-127 in Chinese sediments and their geochronological implications

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    Large variations in pre-nuclear I-129/I-127 ratios in terrestrial environments have been observed, but few investigations have been carried out on how the isotopic composition varies and how it is affected by the terrestrial environment. In this work, lake and river sediments were studied for the first time with the aim of exploring the possible connections between the natural iodine isotopic composition and its sources. The observed higher natural I-129/I-127 ratios compared to those in the marine system suggested that the isotopes did not reach a steady state. Decreasing I-129/I-127 ratios with increasing I-127 contents indicated perturbation of old iodine, and a narrower range of initial equilibrium ratios was suggested based on pre-nuclear ratios derived in the studied sediments

    Surface Enhanced Raman Scattering Silica Substrate Fast Fabrication by Femtosecond Laser Pulses

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    We report the fabrication of surface enhanced Raman spectroscopy (SERS) fused silica glass substrates using fast femtosecond-laser (fs-laser) scan, followed by silver chemical plating. A cross-section enhancement factor (EF) of 2.5×106, evaluated by Rhodamine 6G (10−7 M solution), was obtained. The Raman mapping indicated a good uniformity over the fs-laser scanned area. The dimension and pattern of the SERS activated region can be conveniently controlled by laser 2D scanning, potentially enabling integration of SERS into a high-order optical-chemical analysis system on a glass chip

    Deep deformation detail synthesis for thin shell models

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    In physics-based cloth animation, rich folds and detailed wrinkles are achieved at the cost of expensive computational resources and huge labor tuning. Data-driven techniques make efforts to reduce the computation significantly by utilizing a preprocessed database. One type of methods relies on human poses to synthesize fitted garments, but these methods cannot be applied to general cloth animations. Another type of methods adds details to the coarse meshes obtained through simulation, which does not have such restrictions. However, existing works usually utilize coordinate-based representations which cannot cope with large-scale deformation, and requires dense vertex correspondences between coarse and fine meshes. Moreover, as such methods only add details, they require coarse meshes to be sufficiently close to fine meshes, which can be either impossible, or require unrealistic constraints to be applied when generating fine meshes. To address these challenges, we develop a temporally and spatially as-consistent-as-possible deformation representation (named TS-ACAP) and design a DeformTransformer network to learn the mapping from low-resolution meshes to ones with fine details. This TS-ACAP representation is designed to ensure both spatial and temporal consistency for sequential large-scale deformations from cloth animations. With this TS-ACAP representation, our DeformTransformer network first utilizes two mesh-based encoders to extract the coarse and fine features using shared convolutional kernels, respectively. To transduct the coarse features to the fine ones, we leverage the spatial and temporal Transformer network that consists of vertex-level and frame-level attention mechanisms to ensure detail enhancement and temporal coherence of the prediction. Experimental results show that our method is able to produce reliable and realistic animations in various datasets at high frame rates with superior detail synthesis abilities compared to existing methods

    Judicious Selection of Precursors with Suitable Chemical Valence State for Controlled Growth of Transition Metal Chalcogenides

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    Abstract Transition metal chalcogenides (TMCs) have attracted wide attentions as a class of promising material for both fundamental investigations and electronic applications due to their atomic thin thickness, dangling bond‐free surface, and excellent electronic properties. Specifically, TMCs show outstanding properties such as good thermal conductivity, robust mechanical properties, and extraordinary electronical characteristics, bestowing them utility in both fundamental research and applications. Recently, the development of post‐Moore electronics based on TMCs calls for their large‐size and single‐crystal growth. However, researchers about synthesis usually focus on controlling several growth parameters (such as growth temperature, flow rate, and time). Herein, it is reported that the chemical valence states of transition metal precursors play an important role in controlling the lateral size and crystal quality for TMCs. The study discusses the valence states‐dependent growth mechanism for WS2 and MoS2 from four factors: evaporation temperature, skipping of reaction steps, atomic binding energy of the precursors, and formation energy. In addition, the as‐grown WS2 and MoS2 nanoflakes exhibit good photoelectric response properties. For EuS, the growth results are obviously different by using EuBr3 and EuBr2 as precursors. The studies provide a unique perspective and also new knowledge to controllably grow large‐size and good crystal quality TMCs

    Climate Control of Iodine Isotopic Composition Evidenced by Argentine Entisols Records

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    Abstract The long half‐life of 129I makes it useful for dating marine sediments aged 2–90 Ma. However, the lack of initial value dating hinders its application for dating terrestrial sediments. A large scatter of 129I/127I in prenuclear terrestrial samples has been reported; however, the key influencing factors remain unclear. This study presented iodine isotope data from three Argentine Entisol profiles and developed an iodine‐source model to determine the influence of the source on iodine isotopic composition. The temporal patterns demonstrated clear climate modulations in natural terrestrial iodine isotopes over the last ∼15 Kyr. The model identified rock weathering as a major source of iodine in continental sediments. Higher 129I/127I ratios at mid‐high latitudes arise from weak geomagnetic shielding of cosmic rays and thus a high production rate, implying limited meridional diffusion of atmospheric iodine. These findings reveal that environmental factors are significant for constraining the initial value of terrestrial 129I

    Microstructure and Magnetic Properties Dependence on the Sputtering Power and Deposition Time of TbDyFe Thin Films Integrated on Single-Crystal Diamond Substrate

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    As giant magnetostrictive material, TbDyFe is regarded as a promising choice for magnetic sensing due to its excellent sensitivity to changes in magnetic fields. To satisfy the requirements of high sensitivity and the stability of magnetic sensors, TbDyFe thin films were successfully deposited on single-crystal diamond (SCD) substrate with a Young’s modulus over 1000 GPa and an ultra-stable performance by radio-frequency magnetron sputtering at room temperature. The sputtering power and deposition time effects of TbDyFe thin films on phase composition, microstructure, and magnetic properties were investigated. Amorphous TbDyFe thin films were achieved under various conditions of sputtering power and deposition time. TbDyFe films appeared as an obvious boundary to SCD substrate as sputtering power exceeded 100 W and deposition time exceeded 2 h, and the thickness of the films was basically linear with the sputtering power and deposition time based on a scanning electron microscope (SEM). The film roughness ranged from 0.15 nm to 0.35 nm, which was measured by an atomic force microscope (AFM). The TbDyFe film prepared under a sputtering power of 100 W and a deposition time of 3 h possessed the coercivity of 48 Oe and a remanence ratio of 0.53, with a giant magnetostriction and Young’s modulus effect, suggesting attractive magnetic sensitivity. The realization of TbDyFe/SCD magnetic material demonstrates a foreseeable potential in the application of high-performance sensors

    Osteoporosis and Alveolar Bone Health in Periodontitis Niche: A Predisposing Factors-Centered Review

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    Periodontitis is a periodontal inflammatory condition that results from disrupted periodontal host–microbe homeostasis, manifested by the destruction of tooth-supporting structures, especially inflammatory alveolar bone loss. Osteoporosis is characterized by systemic deterioration of bone mass and microarchitecture. The roles of many systemic factors have been identified in the pathogenesis of osteoporosis, including endocrine change, metabolic disorders, health-impaired behaviors and mental stress. The prevalence rate of osteoporotic fracture is in sustained elevation in the past decades. Recent studies suggest that individuals with concomitant osteoporosis are more vulnerable to periodontal impairment. Current reviews of worse periodontal status in the context of osteoporosis are limited, mainly centering on the impacts of menopausal and diabetic osteoporosis on periodontitis. Herein, this review article makes an effort to provide a comprehensive view of the relationship between osteoporosis and periodontitis, with a focus on clarifying how those risk factors in osteoporotic populations modify the alveolar bone homeostasis in the periodontitis niche

    Factors associated with health-related quality of life in papillary thyroid microcarcinoma patients undergoing radiofrequency ablation: a cross-sectional prevalence study

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    Purpose To explore the association of demographic characteristics, clinical symptoms and the fear of the disease progression factors with the physical and mental summary components of the health-related of life (HRQoL) of the papillary thyroid microcarcinoma (PTMC) patients undergoing radiofrequency ablation (RFA). Methods 123 PTMC survivors undergoing RFA were enrolled in this study from October 2019 to March 2020. Demographic, clinical symptoms and the fear of the disease progression data were collected. SF-36, THYCA-QoL and FoP-Q-SF were used to evaluate the HRQoL of patients, clinical symptoms and the fear of disease progression. A multivariate regression model was performed to evaluate the association between the independent variable and the HRQoL variable. Results The average self-reported HRQoL score was 81.17 ± 15.48 for the PCS and 73.40 ± 18.03 for the MCS. The multivariate linear regression model shows that the factors related to a poorer PCS were dependent for the female patients, the symptoms of neuromuscular and the throat/mouth, the fear of disease progression; the psychological disorder, symptoms of throat/mouth, inability to concentrate were related to worse scores for the MCS. The condition that was most strongly related to a poorer HRQoL (in both PCS and MCS) was the fear of their physical health. Conclusions The factors related to significantly worse HRQoL scores across PCS and MCS for PTMC survivors include the female gender, the symptoms of neuromuscular and the throat/mouth, the psychological disorder, inability to concentrate, and the fear of their own physical health. Identification, management, and prevention of these factors are critical to improving the HRQoL of patients
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