75 research outputs found
The Effect of Initial Creep Damage on Unloading Failure Properties of Sandstone from Macro-mesoscopic Perspective
The aim of this research was to show the effect of initial creep damage on unloading failure of rock from macro-mesoscopic perspective. A series of triaxial creep tests were carried out on sandstone to simulate initial creep damage and then unloading confining pressure tests were performed, respectively. A creep damage variable was proposed to analyze the degree of initial creep damage and the relationship of it with the macroscopic strength parameters was established. The results showed that the unloading amount of confining pressure and residual strength all tend to decrease when the degree of initial creep damage increases. The critical challenge was how to describe the effect of initial creep damage from mesoscopic perspective. This aim was achieved through two steps. In the first step, the mesoscopic properties were analyzed using experimentally obtained SEM images of the rock samples with different levels of initial creep damage. By comparative analysis of porosities in different magnifications, it can be concluded that porosity can’t reflect the effect of initial creep damage very well, thus, other pore parameters are further proposed. In the second step, three pore parameters were calculated by using the Matlab and IPP software, then, the average value of mean pore diameter is determined as the proper evaluation parameter and, finally, the agreement was verified between the mesoscopic pore parameter and creep damage variable
Reflection Spectrum of Two Level Atoms by an Evanescent Laser Wave
An exact solution and numerical calculation of the reflection of two level atoms by atomic mirror are presented. The curve of reflection coefficient against Rabi frequency calculated shows some new features, and the physical machanism underlying is analyzed
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Breathing Signature as Vitality Score Index Created by Exercises of Qigong: Implications of Artificial Intelligence Tools Used in Traditional Chinese Medicine.
Rising concerns about the short- and long-term detrimental consequences of administration of conventional pharmacopeia are fueling the search for alternative, complementary, personalized, and comprehensive approaches to human healthcare. Qigong, a form of Traditional Chinese Medicine, represents a viable alternative approach. Here, we started with the practical, philosophical, and psychological background of Ki (in Japanese) or Qi (in Chinese) and their relationship to Qigong theory and clinical application. Noting the drawbacks of the current state of Qigong clinic, herein we propose that to manage the unique aspects of the Eastern 'non-linearity' and 'holistic' approach, it needs to be integrated with the Western "linearity" "one-direction" approach. This is done through developing the concepts of "Qigong breathing signatures," which can define our life breathing patterns associated with diseases using machine learning technology. We predict that this can be achieved by establishing an artificial intelligence (AI)-Medicine training camp of databases, which will integrate Qigong-like breathing patterns with different pathologies unique to individuals. Such an integrated connection will allow the AI-Medicine algorithm to identify breathing patterns and guide medical intervention. This unique view of potentially connecting Eastern Medicine and Western Technology can further add a novel insight to our current understanding of both Western and Eastern medicine, thereby establishing a vitality score index (VSI) that can predict the outcomes of lifestyle behaviors and medical conditions
Who are the preferential targets for intervention programs related to the female condom among sex workers in Southern China?
The authors used a cluster analysis approach to investigate which female sex workers (FSW) are preferential targets for female condom (FC) intervention programs in southern China. Cross-sectional 6-month (N = 316) and 12-month (N = 217) postintervention surveys of FSW were analyzed. Based on FC attitudes and beliefs, initially suggesting FC use to a partner, practicing insertion, total times ever used, and willingness to use in the future, cluster analysis apportioned women into two clusters, with 50.6% and 58.1% of participants in the likely future FC users group at 6 months and 12 months, respectively. Likely future FC users tended to be from boarding houses, older, currently or previously married, experienced with childbirth, with current multiple sex partners, longer history of sex work, and more unprotected sexual encounters. Focusing FC programs on sectors of the community with more FSW who are likely to use FC may be more costeffective for enhancing FC acceptability and usage. © 2013 The Guilford Press
Arabidopsis Ovate Family Proteins, a Novel Transcriptional Repressor Family, Control Multiple Aspects of Plant Growth and Development
, AtOFP4 has been shown to regulate secondary cell wall formation by interact with KNOTTED1-LIKE HOMEODOMAIN PROTEIN 7 (KNAT7), and AtOFP5 has been shown to regulate the activity of a BEL1-LIKEHOMEODOMAIN 1(BLH1)-KNAT3 complex during early embryo sac development, but little is known about the function of other AtOFPs. genes may also have diverse functions in regulating plant growth and development. Further analysis suggested that AtOFP1 regulates cotyledon development in a postembryonic manner, and global transcript profiling revealed that it suppress the expression of many other genes.Our results showed that AtOFPs function as transcriptional repressors and they regulate multiple aspects of plant growth and development. These results provided the first overview of a previously unknown transcriptional repressor family, and revealed their possible roles in plant growth and development
Synergistic Effect of Functionalized Nickel Nanoparticles and Quercetin on Inhibition of the SMMC-7721 Cells Proliferation
The effect of functionalized nickel (Ni) nanoparticles capped with positively charged tetraheptylammonium on cellular uptake of drug quercetin into hepatocellular carcinoma cells (SMMC-7721) has been explored in this study via microscopy and electrochemical characterization as well as MTT assay. Meanwhile, the influence of Ni nanoparticles and/or quercetin on cell proliferation has been further evaluated by the real-time cell electronic sensing (RT-CES) study. Our observations indicate that Ni nanoparticles could efficiently improve the permeability of cancer cell membrane, and remarkably enhance the accumulation of quercetin in SMMC-7721 cells, suggesting that Ni nanoparticles and quercetin would facilitate the synergistic effect on inhibiting proliferation of cancer cells
Effect of Wet-dry Cycles on Disintegration Characteristics of Clay-bearing Sandstone with UF Cracks
UF cracks in rock masses commonly occur due to the unloading effect, which constantly happens after the variation of in-situ stress field or rock excavation. To study the effect of changes in moisture on rock samples with UF cracks, clay-bearing sandstone from the Triassic Badong group in the Three Gorges Reservoir Area were chosen and investigated. The rock samples with UF cracks are obtained by conducting triaxial unloading confining pressure experiment. The effect of wet-dry cycles on the UF cracks, morphology properties and microstructural features of the UF surface was investigated. The characteristics of particle-size uniformity from the sieve test were obtained by the calculation of RMS of particle contents. The test results show that UF cracks widen significantly and the disintegrated mass increases rapidly in the first three wet-dry cycles, while the fractal dimension of UF surface decreases sharply, but afterwards the disintegrated mass changes gently and the UF surface tends to be flat and smooth. Then, the RMS calculation of particle contents quantitatively evaluate the clay-bearing sandstone’s disintegration properties, which indicate the particle uniformity plays a key role on its disintegration mechanism. Finally, we found that the microstructure of samples from FD group is looser and porous than those from SD group by SEM test. This investigation, considering the similar clay mineral content of all tested samples, demonstrates the closed link between the grain size distribution, microstructural features and the degree of disintegration
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Qigong Exercise Balances Oxygen Supply and Acid-Base to Modulate Hypoxia: A Perspective Platform toward Preemptive Health & Medicine
Qigong is a meditative movement with therapeutic effects and is commonly practiced in Eastern medicine. A growing body of evidence validates its health benefits, leading to mechanistic questions about how it works. We propose a novel mechanism by which the "acid" caused by hypoxia affects metabolism, and the way it is neutralized through Qigong practice involves the body's blood flow and vasculature modifications. Specifically, Qigong exercise generates an oxygen supply and acid-base balance against the hypoxic effects of underlying pathological conditions. We also propose that Qigong exercise mediated and focused on the local hypoxia environment of tissues might normalize the circulation of metabolic and inflammation accumulation in the tumor tissue and restore the normal metabolism of tissues and cells through calm, relaxation, and extreme Zen-style breathing that gravitates toward preemptive health and medicine. Thus, we propose the mechanisms of action related to Qigong, intending to unify Eastern and Western exercise theory
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