Noise Elimination for Coalcutter Vibration Signal Based on Ensemble Empirical Mode Decomposition and an Improved Harris Hawks Optimization Algorithm

The vibration signal of the shearer is one of the important signals for coal and rock cutting mode recognition and fault diagnosis. However, the signal collected in the field contains a large amount of background noise, which is not conducive to subsequent analysis and processing. Therefore, a noise elimination method for coalcutter vibration signal based on Ensemble Empirical Mode Decomposition (EEMD) and an Improved Harris Hawks Optimization (HHO) algorithm is proposed in this paper. The vibration signal is first decomposed by EEMD to generate a series of intrinsic mode functions (IMF). The HHO algorithm was introduced to determine the optimal denoising threshold of each IMF. In addition, the original HHO has been improved to use the natural constant as the base exponential function to determine the escape energy trend line. Simulation results show that compared with the other four denoising methods, the signal waveform processed by this method is smoother. Under different types of signals and the same intensity of noise, the SNR increases by 70.9%, 6.7%, 2.6%, and 10.53% on average, respectively. The MSE decreases by 67.6%, 12.7%, 4.5%, and 5.42% on average. Under the same type of signal and different intensity of noise environment, the SNR is improved by 74.62%, 37.70%, 5.24%, and 39.72% on average, respectively. MSE decreased by 77.38%, 53.10%, 9.88%, and 54.67% on average. Finally, the method is applied to the shearer working state diagnosis system, and its actual effect is verified

Preparation and Characterization of Novel Sulfoaluminate-Cement-Based Nonautoclaved Aerated Concrete

The production of autoclaved aerated concrete via the autoclaving process incurs substantial energy consumption, posing a challenge to sustainable economic development. Herein, a novel nonautoclaved aerated concrete (NAAC) was prepared using sulfoaluminate cement as the primary raw material and aluminum powder as the aerating agent. The physicomechanical characteristics and pore structures of the sulfoaluminate-cement-based (SAC) NAAC (SAC-NAAC) were examined through X-ray diffraction, thermogravimetry, and scanning electron microscopy. The findings revealed that the optimal mechanical attributes of the SAC-NAAC were achieved at a water–cement ratio of 0.55, with a specific content ratio of polycarboxylate superplasticizer–borax–calcium stearate–sodium hydroxide at 0.24%:0.32%:0.36%:2.90%, along with 0.40% aluminum powder. The SAC-NAAC samples, with a bulk density range of 600–750 g/m3, exhibited a compressive strength of 3.55–4.16 MPa, porosity of 45.9–63.5%, and water absorption rate of 60.2–74.4%. The weight loss in the SAC-NAAC with different aluminum powder contents ranged between 15.23% and 16.83%. The prismatic ettringite (AFt) crystals served as the main source of strength for the SAC-NAAC, and AH3 was attached to the AFt surfaces in a microcrystalline gel phase, thereby further enhancing the strength of the SAC-NAAC. Thus, the lightweight, high-strength SAC-NAAC has great potential as a nonautoclaved aerated concrete

Pollution characteristics and chronic health risk assessment of metals and metalloids in ambient PM2.5 in Licheng District, Jinan, China

PM samples were collected at the Wangsheren primary school site in Licheng District of Jinan, China, during 2016. Eleven metals and metalloids including Al, As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sb and Se in PM were measured by inductively coupled plasma-mass spectroscopy. The annual average mass concentration of PM was found to be 88.7\ua0μg\ua0m. The highest PM concentrations were obtained during the heating seasons of winter and spring. The concentrations of metals and metalloids in PM were in a descending order of Al, Pb, Mn, As, Se, Cr, Sb, Ni, Cd, Hg and Be. The enrichment factors showed that Pb, Mn, As, Se, Cr, Sb, Ni, Cd, Hg originated from anthropogenic sources. Factor analysis indicated that the main sources of the metals were coal combustion dust, soil dust, metallurgical industry, brake abrasion of vehicles and other mixed sources. Coal combustion dust was the primary source of metal pollution in PM. Non-carcinogenic risks associated with exposure through the respiratory system were between 6.30 × 10 and 7.62 × 10, which were lower than the safe limit (1). The carcinogenic risks of Cr, As and Cd were 3.17 × 10, 1.52 × 10, 2.22 × 10, respectively, which were higher than the precautionary criterion (10/year). This study indicates that the air pollution of PM is of public health concern in Licheng District of Jinan, particularly related to potential carcinogenic metals of As, Cr and Cd. Intervention action is needed to reduce the emission sources of these elements, especially coal combustion in winter heating season

HBx Sensitizes Cells to Oxidative Stress-induced Apoptosis by Accelerating the Loss of Mcl-1 Protein via Caspase-3 Cascade

Abstract Background Oxidative stress has been implicated in the pathogenesis of a wide spectrum of human diseases, including Hepatitis B virus (HBV)-related liver disease. Hepatitis B virus X protein (HBx) is a key regulator of HBV that exerts pleiotropic activity on cellular functions. Recent studies showed that HBx alters mitochondrial membrane potential, thereby sensitizing cells to pro-apoptotic signals. However, it remains largely unknown whether susceptibility of hepatocytes could be disturbed by HBx under oxidative stress conditions. The purpose of this study is to determine the apoptotic susceptibility of HBx-expressing hepatocytes upon exposure to pro-oxidant stimuli in vitro and in vivo and explore its underlying mechanism. Results Although expression of HBx itself did not activate apoptotic signaling, it significantly enhanced oxidative stress-induced cell death both in vitro and in vivo. Interestingly, this phenomenon was associated with a pronounced reduction of protein levels of Mcl-1, but not other anti-apoptotic Bcl-2 members. Importantly, enforced expression of Mcl-1 prevented HBx-triggered cell apoptosis; conversely, specific knockdown of Mcl-1 exacerbated HBx-induced apoptosis upon exposure to oxidative stress. Furthermore, inhibition of caspase-3 not only abrogated HBx-triggered apoptotic killing but also blocked HBx-induced Mcl-1 loss. Additionally, expression of HBx and Mcl-1 was found to be inversely correlated in HBV-related hepatocellular carcinogenesis (HCC) tissues. Conclusions Our findings indicate that HBx exerts pro-apoptotic effect upon exposure to oxidative stress probably through accelerating the loss of Mcl-1 protein via caspase-3 cascade, which may shed a new light on the molecular mechanism of HBV-related hepatocarcinogenesis.</p

mRNA Vaccines Encoding the HA Protein of Influenza A H1N1 Virus Delivered by Cationic Lipid Nanoparticles Induce Protective Immune Responses in Mice

The design of the mRNA vaccine involves the selection of in vitro transcription (IVT) systems and nonviral delivery vectors. This study aimed to verify the effect of 5&rsquo; and 3&rsquo; untranslated region (UTR) sequences on the translation efficiency of mRNA. Three modes of IVT-mRNA systems (IVT-mRNA-n1/n2/n3) with diverse UTRs were constructed, and EGFP (enhanced green fluorescent protein) and HA (hemagglutinin) gene of H3N2 influenza virus were introduced into each of them. The results showed that the mode of 5&rsquo; and 3&rsquo; UTRs originating from human &beta;-globulin was better than the mode of UTRs from human &alpha;-globulin, and the n3 mode was the best. mEGFP-n3, mH3HA-n3, and mLuciferease-n3 were prepared to compare the effect of cationic lipid nanoparticle (LNP) with that of mannose-conjugated LNP (LNP-Man) on the efficiency of gene delivery. The results showed that the effect of LNP-Man was better than that of LNP both in vitro and in vivo. Choosing appropriate ligands might help in vaccine design. After selecting the IVT-mRNA-n3 system and delivery vectors, mRNA vaccines were constructed against the H1N1 influenza virus, and C57BL/6 mice were immunized through intranasal administration. The results showed that mRNA vaccines could elicit both humoral and cellular immune responses and completely protect mice from the tenfold LD50 H1N1 influenza virus challenge

Hepatitis B Virus X Protein Enhances Cisplatin-Induced Hepatotoxicity via a Mechanism Involving Degradation of Mcl-1 ▿ †

Hepatitis B virus X protein (HBx) is implicated in the pathogenesis of hepatitis B virus (HBV)-associated liver diseases. However, whether HBx has the ability to disturb the susceptibility of hepatocytes to common chemotherapeutic agents remains incompletely understood. Here we demonstrate that HBx enhances cisplatin-induced hepatotoxicity by a mechanism involving degradation of Mcl-1, an antiapoptotic member of the Bcl-2 family. Ectopic expression of HBx sensitized hepatocytes to cisplatin-induced apoptosis, which was accompanied by a marked downregulation of Mcl-1 but not of Bcl-2 or Bcl-xL. Overexpression of Mcl-1 prevented HBx-induced proapoptotic and proinflammatory effects during cisplatin treatment both in vitro and in vivo. HBx-induced dysregulation of Mcl-1 resulted mainly from posttranslational degradation rather than transcription repression. Moreover, a caspase-3 inhibitor effectively abrogated HBx-enhanced Mcl-1 degradation and cell death. Importantly, antioxidants blocked activation of caspase-3 and acceleration of Mcl-1 loss, as well as cell death, in HBx-expressing hepatocytes upon cisplatin exposure in vitro and in vivo. Collectively, these data implicate oxidative stress-dependent caspase-3-mediated degradation of Mcl-1 as a mechanism contributing to HBx-mediated sensitization of cisplatin-induced hepatotoxicity. A combination of cisplatin and antioxidants might provide more advantage than cisplatin alone in the treatment of cancer patients with chronic HBV infection

Selective Identification of Organic Iodine Compounds Using Liquid Chromatography–High Resolution Mass Spectrometry

A method to selectively and sensitively detect organic iodine compounds and identify their structures has been developed using liquid chromatography–high resolution mass spectrometry (LC–HRMS). Using extracted ion chromatograms of product ions (iodine ion) collected on a rapid scanning quadrupole orbitrap mass spectrometer, the retention times of the unknown organic iodine compounds were determined, and the structural information were acquired according to the MS/MS experiments and the matching with reference standards. We have demonstrated the application of this method by identifying unknown organic iodine compounds in seaweed. A total of 28 possible organic iodine peaks were discovered, among them, the accurate mass and element composition of the corresponding precursor ions were identified for 12 peaks, and molecular structures were confirmed for 4 peaks, which were 3-iodo-l-tyrosine, 3,5-diiodo-l-tyrosine, 4-iodophenol, and 2-iodobenzoic acid. This method is expected to lead to the future discovery of new organic iodine compounds via LC–HRMS in different environmental samples, which is crucial for understanding the iodine biogeochemical cycling