41 research outputs found

    Hypoxia-inducible transcription factor-1α promotes hypoxia-induced A549 apoptosis via a mechanism that involves the glycolysis pathway

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    BACKGROUND: Hypoxia-inducible transcription factor-1α (HIF-1α), which plays an important role in controlling the hypoxia-induced glycolysis pathway, is a "master" gene in the tissue hypoxia response during tumor development. However, its role in the apoptosis of non-small cell lung cancer remains unknown. Here, we have studied the effects of HIF-1α on apoptosis by modulating HIF-1α gene expression in A549 cells through both siRNA knock-down and over-expression. METHODS: A549 cells were transfected with a HIF-1α siRNA plasmid or a HIF-1α expression vector. Transfected cells were exposed to a normoxic or hypoxic environment in the presence or absence of 25 mM HEPES and 2-deoxyglucose (2-DG) (5 mM). The expression of three key genes of the glycolysis pathway, glucose transporter type 1(GLUT1), phosphoglycerate kinase 1(PGK1), and hexokinase 1(HK1), were measured using real-time RT-PCR. Glycolysis was monitored by measuring changes of pH and lactate concentration in the culture medium. Apoptosis was detected by TUNEL assay and flow cytometry. RESULTS: Knocking down expression of HIF-1α inhibited the glycolysis pathway, increased the pH of the culture medium, and protected the cells from hypoxia-induced apoptosis. In contrast, over-expression of HIF-1α accelerated glycolysis in A549 cells, decreased the pH of the culture medium, and enhanced hypoxia-induced apoptosis. These effects of HIF-1α on glycolysis, pH of the medium, and apoptosis were reversed by treatment with the glycolytic inhibitor, 2-DG. Apoptosis induced by HIF-1α over-expression was partially inhibited by increasing the buffering capacity of the culture medium by adding HEPES. CONCLUSION: During hypoxia in A549 cells, HIF-1α promotes activity of the glycolysis pathway and decreases the pH of the culture medium, resulting in increased cellular apoptosis

    Prior knowledge-based deep learning method for indoor object recognition and application

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    Indoor object recognition is a key task for indoor navigation by mobile robots. Although previous work has produced impressive results in recognizing known and familiar objects, the research of indoor object recognition for robot is still insufficient. In order to improve the detection precision, our study proposed a prior knowledge-based deep learning method aimed to enable the robot to recognize indoor objects on sight. First, we integrate the public Indoor dataset and the private frames of videos (FoVs) dataset to train a convolutional neural network (CNN). Second, mean images, which are used as a type of colour knowledge, are generated for all the classes in the Indoor dataset. The distance between every mean image and the input image produces the class weight vector. Scene knowledge, which consists of frequencies of occurrence of objects in the scene, is then employed as another prior knowledge to determine the scene weight. Finally, when a detection request is launched, the two vectors together with a vector of classification probability instigated by the deep model are multiplied to produce a decision vector for classification. Experiments show that detection precision can be improved by employing the prior colour and scene knowledge. In addition, we applied the method to object recognition in a video. The results showed potential application of the method for robot vision

    A New Two-Lane Lattice Hydrodynamic Model considering the Traffic Interruption Probability under Honk Environment

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    By accounting for the traffic interruption probability on two-lane highway under honk environment, an extended lattice hydrodynamic model is presented in the paper. In view of the novel model, a series of researches are carried out. The neutral stability condition and the stable condition can be derived through linear analysis. Then, the mKdV equation near the critical point can be obtained by applying nonlinear analysis, which describes the traffic jams according to the kink-antikink density waves. In addition, numerical simulation is performed, which confirms that traffic interruption probability on two-lane highway under honk environment can develop traffic jams by the change of density waves. Also, the phenomenon is consistent with the results of previous theoretical analysis. It shows that accounting for the traffic interruption probability on two-lane highway under honk environment can stabilize the traffic flow efficiently

    Numerical Investigation on the Mechanism of Rock Directional Fracturing Method Controlled by Hydraulic Fracturing in Dense Linear Multiholes

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    Rock directional fracturing is one of the difficult problems in deep mines. Directional fracturing controlled by hydraulic fracturing in dense linear multiboreholes is a novel directional fracturing technology of rock mass, which has been applied to the ground control in mines. In this paper, a physical model experiment was performed to study the fracture propagation process between multiboreholes. The results show that the intersecting of fractures between boreholes caused the sharp fluctuation of injecting water pressure. A directional fracturing plane was formed along with the direction of boreholes layout, and the surface of the fracturing plane is relatively flat. The dynamic initiation and propagation process of cracks between boreholes during directional hydraulic fracturing were simulated. The evolution of poroelastic stress and pore pressure between multiboreholes was analyzed. The numerical results indicated that a poroelastic stress concentration zone and pore pressure increase zone appeared between boreholes in the direction of boreholes layout. The pore pressure distribution is generally an elliptical seepage water pressure zone with the long axis along the direction of the boreholes layout. After the hydraulic fractures are initiated along the direction of the boreholes layout, the poroelastic stress on both sides of fractures decreases

    The utility of HbA1c combined with haematocrit for early screening of gestational diabetes mellitus

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    Abstract Aims To evaluate the utility of glycated haemoglobin A1c (HbA1c) alone and in combination with haematocrit (HCT) for screening gestational diabetes mellitus (GDM) between 12–16 gestational weeks. Methods This prospective study was carried out in the Obstetrics and Gynaecology Hospital of Fudan University from November 2014 to February 2015. In total, 690 pregnant women between 20 and 35 years old were included in this study. All subjects received a routine blood examination for HbA1c and HCT at 12–16 gestational weeks (gw) and a 75-g oral glucose tolerance test at 24–28 gw. Threshold values for the diagnosis of GDM were a plasma glucose concentration of 5.1 mmol/L after fasting, 10.0 mmol/L at 60 min, and 8.5 mmol/L at 120 min. Receiver operating characteristic curves were used to evaluate the diagnostic performance of HbA1c with or without HCT. Results One hundred seven women were diagnosis with GDM at 24–28 gw. An HbA1c cutoff value  38.8%) for the screening of GDM, the area under the receiver operating characteristic curve was 0.604 (95% [CI] 0.509, 0.701). Conclusions Whether the adoption of HbA1c as a screening test for GDM would benefit pregnant women remains to be determined. However, combining HbA1c with HCT for the screening of GDM may be a useful tool to predict GDM

    Fingerprint enhancement using multi-scale classification dictionaries with reduced dimensionality

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    In order to improve the quality of fingerprint with large noise, this paper proposes a fingerprint enhancement method by using a sparse representation of learned multi-scale classification dictionaries with reduced dimensionality. Multi-scale dictionary is used to balance the contradiction between the accuracy and the anti-noise ability, which has been shown to be an ideal solution to reconcile the demands of enhancement quality and computational performance. Principal component analysis (PCA)is applied in our technique for dimension reduction of multi-scale classification dictionaries. Under the quality grading scheme and multi-scale composite windows, the fingerprint patches are enhanced by using a sparse representation of learned multi-scale classification dictionaries with reduced dimensionality according to their priorities. In addition, the multi-scale composite windows help the more high quality spectra diffuse into the low quality fingerprint patches and this can greatly improve the spectra quality of them. Experimental results and comparisons on FVC 2000 and FVC 2004 databases are reported.And it shows that the proposed method yields better result in terms of the robustness of fingerprint enhancement as compared with latest techniques.Moreover, the results show that the proposed algorithm can obtain better identification performanc

    Hypoxia-inducible transcription factor-1α promotes hypoxia-induced A549 apoptosis via a mechanism that involves the glycolysis pathway

    No full text
    Abstract Background Hypoxia-inducible transcription factor-1α (HIF-1α), which plays an important role in controlling the hypoxia-induced glycolysis pathway, is a "master" gene in the tissue hypoxia response during tumor development. However, its role in the apoptosis of non-small cell lung cancer remains unknown. Here, we have studied the effects of HIF-1α on apoptosis by modulating HIF-1α gene expression in A549 cells through both siRNA knock-down and over-expression. Methods A549 cells were transfected with a HIF-1α siRNA plasmid or a HIF-1α expression vector. Transfected cells were exposed to a normoxic or hypoxic environment in the presence or absence of 25 mM HEPES and 2-deoxyglucose (2-DG) (5 mM). The expression of three key genes of the glycolysis pathway, glucose transporter type 1(GLUT1), phosphoglycerate kinase 1(PGK1), and hexokinase 1(HK1), were measured using real-time RT-PCR. Glycolysis was monitored by measuring changes of pH and lactate concentration in the culture medium. Apoptosis was detected by TUNEL assay and flow cytometry. Results Knocking down expression of HIF-1α inhibited the glycolysis pathway, increased the pH of the culture medium, and protected the cells from hypoxia-induced apoptosis. In contrast, over-expression of HIF-1α accelerated glycolysis in A549 cells, decreased the pH of the culture medium, and enhanced hypoxia-induced apoptosis. These effects of HIF-1α on glycolysis, pH of the medium, and apoptosis were reversed by treatment with the glycolytic inhibitor, 2-DG. Apoptosis induced by HIF-1α over-expression was partially inhibited by increasing the buffering capacity of the culture medium by adding HEPES. Conclusion During hypoxia in A549 cells, HIF-1α promotes activity of the glycolysis pathway and decreases the pH of the culture medium, resulting in increased cellular apoptosis.</p

    MicroRNA-222 promotes the proliferation and migration of cervical cancer cells

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    Purpose: This study aimed to investigate the role of small non-coding RNA-222 (microRNA-222; miR-222) in the development of cervical cancer (CC). Methods: Normal and CC specimens were obtained from 18 patients. HeLa and SiHa cells were grown in Dulbecco’s modified Eagle’s medium. RT–PCR, Western blot, migration assay, flow cytometry and immunofluorescence microscopy were used for analyses. Results: When compared with normal cervical tissues, miR-222 was upregulated in human CC, and the extent of up-regulation was associated with the extent and depth of CC invasion. Expression of miR-222 was inversely related to the expression of phosphatase and tensin homolog (PTEN) and p27. The reduced the expression of PTEN and p27 by miR-222 in HeLa cells and SiHa cells was associated with increased proliferation and migration of CC cells. The expression of proteins (E-cadherin and paxillin) related to the proliferation and migration was also elevated. Conclusion: MiR-222 plays an important role in the tumorigenesis of CC, possibly by specifically down-regulating p27Kip1 and PTEN. Our findings suggest that miR-222 may serve as a new therapeutic target in CC
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