27 research outputs found

    Using User Generated Online Photos to Estimate and Monitor Air Pollution in Major Cities

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    With the rapid development of economy in China over the past decade, air pollution has become an increasingly serious problem in major cities and caused grave public health concerns in China. Recently, a number of studies have dealt with air quality and air pollution. Among them, some attempt to predict and monitor the air quality from different sources of information, ranging from deployed physical sensors to social media. These methods are either too expensive or unreliable, prompting us to search for a novel and effective way to sense the air quality. In this study, we propose to employ the state of the art in computer vision techniques to analyze photos that can be easily acquired from online social media. Next, we establish the correlation between the haze level computed directly from photos with the official PM 2.5 record of the taken city at the taken time. Our experiments based on both synthetic and real photos have shown the promise of this image-based approach to estimating and monitoring air pollution.Comment: ICIMCS '1

    All-Electrical Skyrmionic Bits in a Chiral Magnetic Tunnel Junction

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    Topological spin textures such as magnetic skyrmions hold considerable promise as robust, nanometre-scale, mobile bits for sustainable computing. A longstanding roadblock to unleashing their potential is the absence of a device enabling deterministic electrical readout of individual spin textures. Here we present the wafer-scale realization of a nanoscale chiral magnetic tunnel junction (MTJ) hosting a single, ambient skyrmion. Using a suite of electrical and multi-modal imaging techniques, we show that the MTJ nucleates skyrmions of fixed polarity, whose large readout signal - 20-70% relative to uniform states - corresponds directly to skyrmion size. Further, the MTJ exploits complementary mechanisms to stabilize distinctly sized skyrmions at zero field, thereby realizing three nonvolatile electrical states. Crucially, it can write and delete skyrmions using current densities 1,000 times lower than state-of-the-art. These results provide a platform to incorporate readout and manipulation of skyrmionic bits across myriad device architectures, and a springboard to harness chiral spin textures for multi-bit memory and unconventional computing.Comment: 8 pages, 5 figure

    MICROWAVE RESONANCES OF ULTRATHIN CHIRAL MULTILAYERS AND NANOSTRUCTURES

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    Master'sMASTER OF SCIENCE (RSH-FOS

    Effects of calcium on anaerobic acidogenic biofilms

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    Calcium has been found to be involved in formation and development of the bioflims for many species of bacteria, but effects of calcium on anaerobic bioflims for industrial application have rarely been reported. In this study, a mixed-culture of anaerobic bacterial bioflims were grown in lactose cultural medium with various calcium concentrations -- 1.2, 80, 100, 120, 170 and 230 mg/I. Specially designed CSTR reactors were used. The temperature and pH in the reactors were controlled at 35 °C and pH 4.5 for optimal growth of acidogenic bacteria. The influence of calcium on biofllm dry mass, total organic carbon, immobilized calcium concentration and bioflim specific activity were measured. The biofllm mass accumulation was increased by the presence of calcium in the growth medium when calcium concentration was not higher than 120 mg/I. Calcium accumulated in the bioflims increased in proportion to the calcium level in the feed. The bioflims for an increased input calcium concentration showed a trend of decrease in specific activity. The biofllms with a thickness of less than 0.5 mm had the highest specific activity. The optimum calcium concentration for the substrate consumption by the biofilms was 100 -120 mg/i. The bioflims transferred from higher calcium medium to lower calcium medium were more susceptible to sioughing from their support surfaces, indicating calcium’s role in the stability of the bioflim structure.Applied Science, Faculty ofChemical and Biological Engineering, Department ofGraduat

    High-Performance Asymmetric Optical Transmission Based on a Dielectric–Metal Metasurface

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    Asymmetric optical transmission plays a key role in many optical systems. In this work, we propose and numerically demonstrate a dielectric–metal metasurface that can achieve high-performance asymmetric transmission for linearly polarized light in the near-infrared region. Most notably, it supports a forward transmittance peak (with a transmittance of 0.70) and a backward transmittance dip (with a transmittance of 0.07) at the same wavelength of 922 nm, which significantly enhances operation bandwidth and the contrast ratio between forward and backward transmittances. Mechanism analyses reveal that the forward transmittance peak is caused by the unidirectional excitation of surface plasmon polaritons and the first Kerker condition, whereas the backward transmittance dip is due to reflection from the metal film and a strong toroidal dipole response. Our work provides an alternative and simple way to obtain high-performance asymmetric transmission devices

    Flexible and binder-free electrospun Co 3

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    High-Dose Vitamin C Tends to Kill Colorectal Cancer with High MALAT1 Expression

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    Background. Vitamin C (Vc) deficiency is frequently observed in cancer sites and has been proposed to have an antitumor effect. However, the mechanism of Vc’s killing effect is not clear. Besides, epigenetic alterations exhibit significant effects on colorectal cancer (CRC). This study aimed to explore the mechanism of Vc’s killing effect and its association to epigenetic alterations in CRC. Methods. Cell morphology, apoptosis, proliferation, and cycle were assayed to test Vc’s suppressive function in CRC cell lines. Xenograft and peritoneal implantation metastasis models were performed to evaluate the high-dose Vc’s inhibitory effect on tumor growth and metastasis. Immunohistochemistry was used to measure CD31 expression in solid tumors. A literature summary was applied for screening differently expressed long noncoding RNAs (lncRNAs) in CRC tissues and was closely associated with CRC progression. The qPCR was used to detect the expression of these lncRNAs. The association between Vc and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was evaluated in MALAT1-transfected CRC cells and a xenograft model. Results. Vc was confirmed to function in proliferation suppression, apoptosis induction, and S phase arresting in CRC cell lines. High-dose Vc, but not physiologically low-dose Vc, was identified as a suppressive function on tumor growth in xenograft models and an inhibitory effect on implantation metastasis in peritoneal implantation metastasis mice. Furthermore, a consistent downregulation of MALAT1 induced by Vc was verified among CRC cell lines and tumor tissues from both mouse models. Finally, experiments on MALAT1-knockdown CRC cells and its xenograft model suggested that Vc had a tendency in killing CRC with high MALAT1 expression. Conclusions. Our findings demonstrate that high-dose Vc has more efficiency in suppressing CRC with higher MALAT1 expression. It gives high-dose Vc the possibility of a better curative effect on CRC with overexpressed MALAT1. Further clinical studies are still needed

    Finite element analysis of intramedullary nailing and double locking plate for treating extra-articular proximal tibial fractures

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    Abstract Background Proximal tibia fractures are one of the most familiar fractures. Surgical approaches are usually needed for anatomical reduction. However, no single treatment method has been widely established as the standard care. Our present study aims to compare the stress and stability of intramedullary nails (IMN) fixation and double locking plate (DLP) fixation in the treatment of extra-articular proximal tibial fractures. Methods A three-dimensional (3D) finite element model of the extra-articular proximal tibial fracture, whose 2-cm bone gap began 7 cm from the tibial plateau articular surface, was created fixed by different fixation implants. The axial compressive load on an adult knee during single-limb stance was imitated by an axial force of 2500 N with a distribution of 60% to the medial compartment, while the distal end was fixed effectively. The equivalent von Mises stress and displacement of the model was used as the output measures for analysis. Results The maximal equivalent von Mises stress value of the system in the IMN model was 293.23 MPa, which was higher comparing against that in the DLP fixation model (147.04 MPa). And the mean stress of the model in the IMN model (9.25 MPa) was higher than that of the DLP fixation system in terms of equivalent von Mises stress (EVMS) (P < 0.0001). The maximal value of displacement (sum) in the IMN system was 8.82 mm, which was lower than that in the DLP fixation system (9.48 mm). Conclusions This study demonstrated that the stability provided by the locking plate fixation system was superior to the intramedullary nails fixation system and served as an alternative fixation for the extra-articular proximal tibial fractures of young patients

    The Severity of CVB3-Induced Myocarditis Can Be Improved by Blocking the Orchestration of NLRP3 and Th17 in Balb/c Mice

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    Background. The functional characteristics of NLRP3 in the pathogenesis of coxsackievirus B3- (CVB3-) induced viral myocarditis (VMC) have not been fully elucidated, and the targeted therapeutic effect of NLRP3 or its related pathway in VMC has not been reported. Method. In this work, the change patterns of NLRP3- and Th17-related factors were detected during the pathological process of CVB3-induced VMC in Balb/c mice. The correlation between NLRP3 and Th17 cells during the VMC process was analyzed by Spearman test. The coculture system of spleen CD4+ T and bone marrow CD11c+ DC cells was set to explore the orchestration of NLRP3 and Th17 in the pathological development of VMC in vitro. Anti-IL-1β antibody or NLRP3-/- Balb/c were used to block the NLRP3 pathway indirectly and directly to analyze the NLRP3-targeting therapeutic value. Results. The change patterns of NLRP3- and Th17-related molecules in the whole pathological process of mouse CVB3-induced VMC were described. Through Spearman correlation analysis, it was confirmed that there was a close correlation between NLRP3 and Th17 cells in the whole pathological process of VMC. And the interaction mode between NLRP3 and Th17 was preliminarily explored in the cell experiment in vitro. Under the intervention of an anti-IL-1β antibody or NLRP3 knockout, the survival rate of the intervention group was significantly improved, the degree of myocardial inflammation and fibrosis was significantly alleviated, and the content of myocardial IL-17 and spleen Th17 was also significantly decreased. Conclusion. Our findings demonstrated a key role of the NLRP3 inflammasome and its close relationship with Th17 in the pathological progression of CVB3-induced VMC and suggested a possible positive feedback-like mutual regulation mechanism between the NLRP3 inflammasome and Th17 in vitro and in the early stage of CVB3 infection. Taking NLRP3 as a new starting point, it provides a new target and idea for the prevention and treatment of CVB3-induced VMC

    Lack of Efficacy of Combined Carbohydrate Antigen Markers for Lung Cancer Diagnosis

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    Background. Lung cancer (LC) is top-ranked in cancer incidence and is the leading cause of cancer death globally. Combining serum biomarkers can improve the accuracy of LC diagnosis. The identification of the best potential combination of traditional tumor markers is essential for LC diagnosis. Patients and Methods. Blood samples were collected from 132 LC cases and 118 benign lung disease (BLD) controls. The expression levels of ten serum tumor markers (CYFR21, CEA, NSE, SCC, CA15-3, CA 19-9, CA 125, CA50, CA242, and CA724) were assayed, and that the expression in the levels of tumor markers were evaluated, isolated, and combined in different patients. The performance of the biomarkers was analyzed by receiver operating characteristic (ROC) analyses, and the difference between combinations of biomarkers was compared by Chi-square (χ2) tests. Results. As single markers, CYFR21 and CEA showed good diagnostic efficacy for nonsmall cell lung cancer (NSCLC) patients, while NSE and CEA were the most sensitive in the diagnosis of small cell lung cancer (SCLC). The area under the curve (AUC) value was 0.854 for the panel of four biomarkers (CYFR21, CEA, NSE, and SCC), 0.875 for the panel of six biomarkers (CYFR21, CEA, NSE, SCC, CA125, and CA15-3), and 0.884 for the panel of ten markers (CYFR21, CEA, NSE, SCC, CA125, CA15-3, CA19-9, CA50, CA242, and CA724). With a higher sensitivity and negative predictive value (NPV), the diagnostic accuracy of the three panels was better than that of any single biomarker, but there were no statistically significant differences among them (all P values > 0.05). However, the panel of six carbohydrate antigen (CA) biomarkers (CA125, CA15-3, CA19-9, CA50, CA242, and CA724) showed a lower diagnostic value (AUC: 0.776, sensitivity: 59.8%, specificity: 73.0%, and NPV: 60.4%) than the three panels (P value < 0.05). The performance was similar even when analyzed individually by LC subtypes. Conclusion. The biomarkers isolated are elevated for different types of lung cancer, and the panel of CYFR21, CEA, NSE, and SCC seems to be a promising serum biomarker for the diagnosis of lung cancer, while the combination with carbohydrate antigen markers does not improve the diagnostic efficacy
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