Graphene nanosheets (GNS) with and without surface functionalization were used as the reinforcements to prepared the composites with thermoplastic polyester elastomer (TPEE) by melting mixing. The ...results show that the presence of GNS improves modulus, yield and tensile strengths of TPEE, and the surface functionalization of GNS further improves its reinforcing effect because of enhanced interfacial interactions. However, the elongation levels also increase in the presence of GNS, which indicates the increased elastoplasticity and viscoplasticity of system. This is because the discrete hard poly(butylene terephthalate) domains of TPEE are enriched on the surface of GNS and form ‘ball bearing’ structure in composites, leading to increased deformation ability of soft continuous poly(tetramethylene glycol) of TPEE during large-scale deformation. Thus, the composites show more amounts of tensile cycles with shorter true strain plateau associated with onset of chain disentangling during cyclic tensile tests. This ‘bearing ball’ effect, however, is not evident in small-scale viscoelastic deformation because the presence of GNS restrains creep of TPEE. In this case, the impeding effect of GNS on the deformation of TPEE chain coils is the dominant role. This work provides useful information on structure design and control of the GNS filled thermoplastic elastomer composites.
The current digital speech deletion and insertion tampering detection methods mainly employes the extraction of phase and frequency features of the Electrical Network Frequency (ENF). However, there ...are some problems with the existing approaches, such as the alignment problem for speech samples with different durations, the sparsity of ENF features, and the small number of tampered speech samples for training, which lead to low accuracy of deletion and insertion tampering detection. Therefore, this paper proposes a tampering detection method for digital speech deletion and insertion based on ENF Fluctuation Super-vector (ENF-FSV) and deep feature learning representation. By extracting the parameters of ENF phase and frequency fitting curves, feature alignment and dimensionality reduction are achieved, and the alignment and sparsity problems are avoided while the fluctuation information of phase and frequency is extracted. To solve the problem of the insufficient sample size of tampered speech for training, the ENF Universal Background Model (ENF-UBM) is built by a large number of untampered speech samples, and the mean vector is updated to extract ENF-FSV. Considering the shallow representation of ENF features with not highlighting important features, we construct an end-to-end deep neural network to strengthen the attention to the abrupt fluctuation information by the attention mechanism to enhance the representational power of the ENF-FSV features, and then the deep ENF-FSV features extracted by the Residual Network (ResNet) module are fed to the designed classification network for tampering detection. The experimental results show that the method in this paper exhibits higher accuracy and better robustness in the Carioca, New Spanish, and ENF High-sampling Group (ENF-HG) databases when compared with the state-of-the-art methods.
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•The ENF fluctuation super vector is extracted for audio tampering detection.•An end-to-end DNN is designed for deletion and insertion tampering detection.•Experiments have verified that the proposed method outperforms the SOTA methods.
To identify the characteristics of esophageal motility abnormalities in patients with gastroesophageal reflux disease (GERD) and its influence on esophageal acid exposure.
Patients with typical ...reflux symptoms and diagnosis of reflux esophagitis (RE) or non-erosive reflux disease (NERD), and healthy subject were enrolled in this prospective controlled study. The esophageal manometry and esophageal 26 hours pH monitoring were performed. GERD patients were divided into 3 groups according to their esophageal motility abnormalities: ① low lower esophageal sphincter pressure (LESP) group, ② ineffective esophageal motivation (IEM) group, ③ IEM and low LESP group. Esophageal acid exposure was analyzed among different groups.
A total of 27 GERD patients (15 RE, 12 NERD) and 10 healthy subjects were enrolled in this study. The esophageal motility abnormalities in GERD patients mainly presented as the decrease of LESP and distal esophageal body pressure. The proportion of 3 kinds of esophageal motility abnormalities ha
Theoretically calculation and laboratory experiments were performed to investigate the horizontal force exerted by internal solitary wave (ISW) on small circular cylindrical structures. Improvement ...in calculation of drag force and inertia force by introducing two-drag-coefficient method and spatial derivative of velocity into the calculation of force by eigenfunction was made based on systematically study on theoretical foundations. Particle image velocimetry (PIV) method and high precision force sensor were used to measure the velocity and force exerted by ISW, respectively. ISW waveform was traced by analyzing image frames follow grayscale threshold method. For the first time, components of horizontal force were calculated from PIV data, which show good agreement with theoretical one. Moreover, series comparisons between experimental data and calculational results were carried out to examine the proposed method. The results show ideal accuracy of the method and significant improvement comparing to the traditional method.
•Improve calculation accuracy of inertia and drag force induced by ISW.•Calculate force components from PIV data and compare with theoretical results.•Ideal accuracy of the proposed method was validated by experimental data.
Abstract
A proper DNA damage response (DDR) is essential to maintain genome integrity and prevent tumorigenesis. DNA double-strand breaks (DSBs) are the most toxic DNA lesion and their repair is ...orchestrated by the ATM kinase. ATM is activated via the MRE11–RAD50–NBS1 (MRN) complex along with its autophosphorylation at S1981 and acetylation at K3106. Activated ATM rapidly phosphorylates a vast number of substrates in local chromatin, providing a scaffold for the assembly of higher-order complexes that can repair damaged DNA. While reversible ubiquitination has an important role in the DSB response, modification of the newly identified ubiquitin-like protein ubiquitin-fold modifier 1 and the function of UFMylation in the DDR is largely unknown. Here, we found that MRE11 is UFMylated on K282 and this UFMylation is required for the MRN complex formation under unperturbed conditions and DSB-induced optimal ATM activation, homologous recombination-mediated repair and genome integrity. A pathogenic mutation MRE11(G285C) identified in uterine endometrioid carcinoma exhibited a similar cellular phenotype as the UFMylation-defective mutant MRE11(K282R). Taken together, MRE11 UFMylation promotes ATM activation, DSB repair and genome stability, and potentially serves as a therapeutic target.
To summarize the present status of health emergency management assessment in China, a comprehensive search of Chinese databases for research that explicitly mention health emergency assessment ...indicators and indicator systems was performed. Studies were evaluated using the Ekman quality assessment tool, and data were extracted with an original extraction form. Sixty-one studies were included. There are many types and methods of health emergency management assessment in China, and the dimensions and the indicators involved are complex. Legal, regulatory, and policy bases for such assessment need to be further strengthened. The relevance of the entire assessment process and its practical application should be enhanced. In the occupational practice, appropriate evaluation methods should be selected according to respective evaluation purposes, evaluation objects, and contents. Laws, regulations, and policies in the evaluation of health emergency management should be improved. Finally, further correlational research on health emergency management evaluation system processes should be explored and improved.
We have proposed and experimentally demonstrated a sapphire-derived fiber (SDF) and silica capillary-based compound Fabry-Pérot interferometer (FPI) for high-pressure and high-temperature sensing. ...The SDF owns high alumina dopant concentration core, which can generate a mullite crystallization region during an arc discharge process. The crystallization region acts as a reflective interface to form one FPI in the SDF. The other FPI contains an air cavity constructed by the silica capillary and is used for high-pressure sensing. Both gas pressure within a range from 0 MPa to 4 MPa and temperature within a range from 20°C to 700°C are measured. Experimental results show that the wavelength shift of the FPI versus the applied pressure is linear at each tested temperature. The pressure sensitivity is measured to be 5.19 nm/MPa at a high temperature of 700°C, and the linear responses show excellent repeatability with linearity of 0.999. Meanwhile, the proposed FPI can stably function at a high temperature of 700°C with a temperature sensitivity of 0.013 nm/°C. The proposed FPI sensor provides a promising candidate for simultaneous measurement of high pressure and high temperature in extreme conditions.
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