64 research outputs found

    Persistent Josephson tunneling between Bi2_2Sr2_2CaCu2_2O8+x_{8+x} flakes twisted by 45^\circ across the superconducting dome

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    There is a heated debate on the Josephson effect in twisted Bi2_2Sr2_2CaCu2_2O8+x_{8+x} flakes. Recent experimental results suggest the presence of either anomalously isotropic pairing or exotic dd+idd-wave pairing, in addition to the commonly believed dd-wave one. Here, we address this controversy by fabricating ultraclean junctions with uncompromised crystalline quality and stoichiometry at the junction interfaces. In the optimally doped regime, we obtain prominent Josephson coupling (2-4 mV) in multiple junctions with the twist angle of 45^\circ, in sharp contrast to a recent report that shows two orders of magnitude suppression around 45^\circ from the value at 0^\circ. We further extend this study to the previously unexplored overdoped regime and observe pronounced Josephson tunneling at 45^\circ together with Josephson diode effect up to 50 K. Our work helps establish the persistent presence of an isotropic pairing component across the entire superconducting phase diagram.Comment: 6 pages, 5 figure

    Study on damage mechanism and treatment of water sprayed roof in Jurassic stratum roadway

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    The roof of the Jurassic main coal seam in western China generally contained low level weak rich water layer, which led to the long-term watering of the roof of the coal roadway especially the roof anchor cable hole and the reduction of the roof surrounding rock strength and the roof support effect, and affected the safety of the coal roadway roof. In order to study the damage mechanism and control measures of the water sprayed roof, the No.414106 auxiliary transportation water spraying area of Yangjiacun Coal Mine of Shuangxin Mining in Inner Mongolia was taken as the research object. Through field investigation and roof drilling sampling, it could be seen that there were obvious water conducting cracks in the area 4m above the roof of the roadway in the synclinal area. The water flowing from the anchor cable hole was in a linear water spraying state. The roof surrounding rock had a large degree of deflection, and some anchor cable anchorage sections were separated from the surrounding rock. The mineral composition analysis and water physical test showed that the clay minerals in the roof sandy mudstone contain up to 73% kaolinite, and the softening coefficient is 0.162, which had obvious water softening characteristics. At the initial stage, the roof of the coal roadway in the water spraying area was mainly destroyed by hydrostatic pressure, and the water softening property reduced the mechanical properties of the fracture structural plane, which led to the expansion of the size of the surrounding rock fractures in shear under the action of hydrostatic pressure. In the later stage, the roof surrounding rock was mainly destroyed by hydrodynamic pressure, which was mainly manifested in the deformation and expansion of fracture structural plane, displacement of fracture fillings, piping, etc. The destruction speed of roof surrounding rock was gradually accelerated. The whole process of surrounding rock of water drenching roadway roof from ground pressure appearance deformation and crack softening expansion to piping corrosion failure was analyzed. According to the main forms of the surrounding rock failure of roof drilling (physical softening, seepage failure, suction corrosion expansion failure, scouring deformation failure), it was divided into four different stages. The criteria for determining the development stage of roof failure of roadway drenching water had been formed with the main forms of roof drilling surrounding rock failure, the flow state of the roof anchor cable hole, roof surrounding rock fracture development characteristics and water control reinforcement principles as the key indicators. Combined with the site conditions, the 414106 auxiliary transportation water spraying area was the Ⅲ stage of the development of spraying roof damage. The structural form of anchor cable sealing grouting (drainage) and the principle of “deep hole drainage + shallow water sealing + deep reinforcement + high pressures support” were proposed for the roof of the roadway in the spraying area. An integrated reinforcement scheme of anchoring, sealing and grouting, which combined the reinforcement of high pre-tightened long anchor cables and sealing and grouting on the roof of the roadway in the water-spraying area, had been formulated. According to the field industrial test and rock pressure monitoring, the effect of roof water control and surrounding rock reinforcement was achieved

    Bufei Huoxue Capsule Attenuates PM2.5-Induced Pulmonary Inflammation in Mice

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    Atmospheric fine particulate matter 2.5 (PM 2.5) may carry many toxic substances on its surface and this may pose a public health threat. Epidemiological research indicates that cumulative ambient PM2.5 is correlated to morbidity and mortality due to pulmonary and cardiovascular diseases and cancer. Mitigating the toxic effects of PM2.5 is therefore highly desired. Bufei Huoxue (BFHX) capsules have been used in China to treat pulmonary heart disease (cor pulmonale). Thus, we assessed the effects of BFHX capsules on PM2.5-induced pulmonary inflammation and the underlying mechanisms of action. Using Polysearch and Cytoscape 3.2.1 software, pharmacological targets of BFHX capsules in atmospheric PM2.5-related respiratory disorders were predicted and found to be related to biological pathways of inflammation and immune function. In a mouse model of PM2.5-induced inflammation established with intranasal instillation of PM2.5 suspension, BFHX significantly reduced pathological response and inflammatory mediators including IL-4, IL-6, IL-10, IL-8, TNF-α, and IL-1β. BFHX also reduced keratinocyte growth factor (KGF), secretory immunoglobulin A (sIgA), and collagen fibers deposition in lung and improved lung function. Thus, BFHX reduced pathological responses induced by PM2.5, possibly via regulation of inflammatory mediators in mouse lungs

    Improved Biocompatibility of Novel Biodegradable Scaffold Composed of Poly-L-lactic Acid and Amorphous Calcium Phosphate Nanoparticles in Porcine Coronary Artery

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    Using poly-L-lactic acid for implantable biodegradable scaffold has potential biocompatibility issue due to its acidic degradation byproducts. We have previously reported that the addition of amorphous calcium phosphate improved poly-L-lactic acid coating biocompatibility. In the present study, poly-L-lactic acid and poly-L-lactic acid/amorphous calcium phosphate scaffolds were implanted in pig coronary arteries for 28 days. At the follow-up angiographic evaluation, no case of stent thrombosis was observed, and the arteries that were stented with the copolymer scaffold had significantly less inflammation and nuclear factor-κB expression and a greater degree of reendothelialization. The serum levels of vascular endothelial growth factor and nitric oxide, as well the expression of endothelial nitric oxide synthase and platelet-endothelial cell adhesion molecule-1, were also significantly higher. In conclusion, the addition of amorphous calcium phosphate to biodegradable poly-L-lactic acid scaffold minimizes the inflammatory response, promotes the growth of endothelial cells, and accelerates the reendothelialization of the stented coronary arteries

    Joint Associations of Maternal Gestational Diabetes and Hypertensive Disorders of Pregnancy With Overweight in Offspring

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    Objectives: Either maternal gestational diabetes mellitus (GDM) or hypertensive disorder of pregnancy (HDP) is associated with an increased risk of obesity in the offspring. However, their joint associations with obesity in offspring remain unclear. We investigated the joint associations of maternal GDM and HDP with childhood overweight in offspring.Methods: We performed a large study in 1967 mother-child pairs. Maternal GDM was diagnosed according to the 1999 World Health Organization (WHO) criteria. HDP was defined as self-reported doctor-diagnosed hypertension or treatment of hypertension (including gestational hypertension, preeclampsia, sever preeclampsia or eclampsia) after 20 weeks of gestation on the questionnaire. Body mass index (BMI) for age Z-score and childhood overweight were evaluated according to WHO growth reference. We used the general linear models to compare children's Z score for BMI and logistic regression models to estimate odds ratios of childhood overweight according to maternal different status of GDM and HDP.Results: Offspring of mothers with both GDM and HDP had a higher BMI for age Z-score (0.63 vs. 0.03, P <0.001) than children born to normotensive and normoglycemic pregnancy. After adjustment for maternal and children's major confounding factors, joint GDM and HDP were associated with increased odds ratios of offspring's overweight compared with normotensive and normoglycemic pregnancy (2.97, 95% confidence intervals [CIs] 1.65–5.34) and GDM alone (2.06, 95% CIs 1.20–3.54), respectively. After additional adjustment for maternal pre-pregnancy BMI and gestational weight gain, joint maternal GDM, and HDP was still associated with an increased risk of offspring's overweight compared with the maternal normotensive, and normoglycemic group but became to have a borderline increased risk compared with the maternal GDM alone group.Conclusions: Maternal GDM alone or joint GDM and HDP were associated with increased ratios of offspring's overweight.Peer reviewe

    A fast edge detection algorithm using binary labels

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    Edge detection (for both open and closed edges) from real images is a challenging problem. Developing fast algorithms with good accuracy and stability for noisy images is difficult yet and in demand. In this work, we present a variational model which is related to the well-known Mumford-Shah functional and design fast numerical methods to solve this new model through a binary labeling processing. A pre-smoothing step is implemented for the model, which enhances the accuracy of detection. Ample numerical experiments on grey-scale as well as color images are provided. The efficiency and accuracy of the model and the proposed minimization algorithms are demonstrated through comparing it with some existing methodologies.Published versio

    Evaluation of Tourism Development Potential on Provinces along the Belt and Road in China: Generation of a Comprehensive Index System

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    The evaluation of tourism development potential (TDP) is the crucial foundation and critical step for sustainable regional tourism development. Prior studies mainly evaluate TDP through the univariate potential model and the multi-indicator descriptive evaluation. However, these two methods have only limited effectiveness for the destination’s TDP in the context of the mesoscale level. Thus, this study aims to develop an effective multi-dimensional mesoscale to evaluate the destination’s TDP and construct a potential index model. Based on the literature review, this study develops four rule layers (tourism supply and consumption (X1), the demand and purchasing power of tourist source (X2), development value of destination resources (X3), and the contribution of the destination’s tourism industry (X4)) and 31 factor layers. All the factor layers are then assigned values based on the provincial statistics in China in 2019. Through SPSS 24.0, the current study uses the principal component analysis (PCA) to construct a provincial TDP index model for the research area: Y=0.2573X1+0.1305X2+0.3177X3+0.2945X4. The results show significant regional differences in the TDP index of the provinces along the Belt and Road (study area) in China. Among them, Guangdong has the most extensive TDP index, Qinghai has the smallest TDP index. The study also uses ArcGIS 10.2 for the function of kernel density analysis to visualize provincial TDP and finds significant spatial differences and a central-edge distribution pattern across provinces

    Network-based drug repurposing for potential stroke therapy

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    Stroke is the leading cause of death and disability worldwide, with a growing number of incidences in developing countries. However, there are currently few medical therapies for this disease. Emerged as an effective drug discovery strategy, drug repurposing which owns lower cost and shorter time, is able to identify new indications from existing drugs. In this study, we aimed at identifying potential drug candidates for stroke via computationally repurposing approved drugs from Drugbank database. We first developed a drug-target network of approved drugs, employed network-based approach to repurpose these drugs, and altogether identified 185 drug candidates for stroke. To validate the prediction accuracy of our network-based approach, we next systematically searched for previous literature, and found 68 out of 185 drug candidates (36.8 %) exerted therapeutic effects on stroke. We further selected several potential drug candidates with confirmed neuroprotective effects for testing their anti-stroke activity. Six drugs, including cinnarizine, orphenadrine, phenelzine, ketotifen, diclofenac and omeprazole, have exhibited good activity on oxygen-glucose deprivation/reoxygenation (OGD/R) induced BV2 cells. Finally, we showcased the anti-stroke mechanism of actions of cinnarizine and phenelzine via western blot and Olink inflammation panel. Experimental results revealed that they both played anti-stroke effects in the OGD/R induced BV2 cells via inhibiting the expressions of IL-6 and COX-2. In summary, this study provides efficient network-based methodologies for in silico identification of drug candidates toward stroke
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