Abstract
In order to further improve accuracy and stability of detection of combustion coal fallout propensity of cigarettes, author of the paper adopted computational fluid dynamics (CFD) technology ...for a three-dimensional numerical simulation of exhaust system of detection instrument, aiming to study characteristics of flow field near cigarettes. Moreover, a simulation model of eight-channel exhaust enclosure was established, obtaining vector diagram for flow velocity of flow field, velocity contour diagram, and pressure distribution cloud diagram. According to findings, flow field of eight channels is evenly distributed, with slow flow velocity around the instrument but furious inside channels. The wind velocity of cigarette monitoring channel is stable at about 200mm/s specified as per standard. However, there is significant change in pressure and flow velocity at the corners of channels, causing local turbulence. In experiments, average wind velocity of 8 monitoring channels was measured, and simulation results were compared with experiment data. Eventually, a conclusion is drawn that simulation result at cigarette monitoring channels changes consistently with the experimental data, with small errors as a whole. Therefore, the designed exhaust system complies with regulations on wind velocity stipulated by YC/T558-2018 Cigarettes—Determination of Combustion Coal Fallout Propensity of Burning Cigarettes. In a word, this paper is hoped to provide technical support for analogue simulation of exhaust system of cigarette detection instrument, and improve detection accuracy.
. Electrochemical etching is widely used to process refractory metals such as tungsten and molybdenum. Flow field is one of the crucial factors that influence the surface quality in electrochemical ...etching. In this paper, the electrochemical etching flow field was analyzed via FLUENT, the characteristics of flow field in electrochemical etching are studied, furthermore, the effects of four different outlet forms of electrolyte on flow field uniformity, electrolyte velocity and pressure distribution are investigated. Under the same electrolyte flow rate, the flow field characteristics of different outlet forms are analyzed by velocity vector diagram, pressure distribution nephogram, velocity and pressure curve diagram. The simulation results indicate that stable electrolyte velocity and uniform pressure distribution of flow field are obtained when the outlet form of electrolyte adopts the optimized flat. Finally, the fixture for this outlet form is designed and fabricated, and experimental verification is carried out, which shown that the flow field is uniform and the crystal plane of the workpiece is well-distributed which according with the process requirements.
In this study, we conducted a clinical analysis of lymphocyte subtypes in 268 patients with Parkinson＇s disease （PD） to assess their clinical impact as a potential marker of advanced PD in Chinese ...patients. The participants comprised 268 sporadic PD patients and 268 healthy controls. The numbers of natural killer （NK） cells and CD3＋, CD3＋CD4＋, CD3＋CD8＋, and CD19＋ lympho- cytes from peripheral blood were determined by immunos- taining and flow cytometric analysis and the percentages of these CD＋ T cells were calculated. The ratio of regulatory T （Treg）/helper T 17 （Thl7） lymphocytes from 64 PD patients and 46 controls was determined by flow cytometric analysis. The results showed that the percentage of NK cells was higher in advanced PD patients than in controls （22.92% ± 10.08% versus 19.76% ±10.09%, P= 0.006）, while CD3＋ T cells are decreased （62.93% ±9.27% versus 65.75% ± 9.13%, P = 0.005）. The percentage of CD19＋ B cells in male patients was lower （P = 0.021） than in female patients, whereas NK cells were increased （P 〈 0.0001）. The scores on the Unified Parkinson＇s Disease Rating Scale （UPDRS） and the Non-Motor Symptoms Scale in late-onset PD patients were significantly higher than those in earlyonset patients （P = 0.024 and P = 0.007, respectively）. The percentage of CD19＋ B cells in patients with UPDRS scores 〉24 was lower than in those with scores 〈24 （10.17% ± 4.19% versus 12.22% ± 5.39%, P = 0.009）. In addition, the Treg/Th17 ratio in female patients was higher than that in female controls （13.88 ± 6.32 versus 9.94 ±4.06, P = 0.042）. These results suggest that the percentages of NK cells, CD3＋ T cells, and CD19＋ B cells along with the Treg/Th17 ratio in peripheral blood may be used to predict the risk of PD in Chinese individuals and provide fresh avenues for novel diagnostic biomarkers and therapeutic designs.
The stable operation of a variable frequency pump is of great importance to the management of a water supply project. Analyzing the operation performance based on monitoring data is necessary for ...maintaining the stable operation of a variable frequency pump. Several sensors are installed at six monitoring points on the pump to collect signals including vibration velocity, vibration acceleration and vibration displacement. Monitoring signals are preprocessed by smoothing, adjusting waveform trend and filtering on the basis of Fast Fourier Transform (FFT). Then, the vibration features are extracted by power spectrum analysis and cepstrum analysis methods. According to the extracted features, the vibration law and actual operation performance of a variable frequency pump under different operating conditions are analyzed. Results indicate that the vibration amplitude of the pump varies sharply under the operating conditions of 15 Hz, 20 Hz and 30 Hz, 35 Hz. The operating condition of 0 Hz, 15 Hz is the restricted operating area of the pump. The vibration and noise continue increasing under the operating conditions of 35 Hz, 50 Hz and reach the maximum values at 50 Hz. Therefore, the optimal operating is within the range of 20 Hz, 30 Hz. Finally, by analyzing the critical values of the operating conditions, the fault diagnosis and the evaluation of the operating status are conducted.
γ-interferon-inducible protein-16 (IFI16), a key DNA sensor, triggers downstream STING-dependent type I interferon (IFN-I) production and antiviral immunity. However, it is still unclear how to ...negatively regulate IFI16 to avoid excessive IFN-I production and autoimmunity. Here, we find that STING directly interacts with IFI16 and facilitates IFI16 degradation via the ubiquitin-proteasome pathway by recruiting the E3 ligase TRIM21. The 1-pyrin region of IFI16 is responsible for the IFI16-STING interaction, and the first three lysines in the N-terminal region of IFI16 are the key sites that lead to STING-mediated IFI16 ubiquitination and degradation. Compared to wild-type IFI16, a higher level of viral DNA triggered IFN-β and antiviral IFN-stimulated gene expression, and thus less HSV-1 infection, was observed in the cells transfected with IFI16-K3/4/6R, an IFI16 mutant that is resistant to degradation. STING-mediated negative feedback regulation of IFI16 restricts IFN-I overproduction during antiviral immunity to avoid autoimmune diseases.
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•Overexpression of STING facilitates IFI16 degradation•E3 ligase TRIM21 plays a role in STING-mediated IFI16 degradation•IFI16-K3/4/6R mutation stabilizes IFI16 protein•IFI16-K3/4/6R facilitates type I IFN production
Li et al. show that STING mediates negative feedback regulation of IFI16 and restricts type I IFN overproduction during immune responses to viruses such as HSV-1.
Rubber used in tire is usually strengthened by nanofiller, and the most popular nanofiller for tire tread rubber is nano silica, which can not only strengthen rubber but also lower the tire rolling ...resistance to reduce fuel consumption. However, silica particles are difficult to disperse in the rubber matrix because of the abundant silicon hydroxyl on their surface. Silane coupling agents are always used to modify silica and improve their dispersion, but a large number of volatile organic compounds (VOCs) are emitted during the manufacturing of the nanosilica/rubber composites because of the condensation reaction between silane coupling agents and silicon hydroxyl on the surface of silica. Those VOCs will do great harm to the environment and the workers’ health. In this work, epoxidized solution polymerized styrene-butadiene rubbers (ESSBR) with different epoxy degrees were prepared and used as macromolecular coupling agents aimed at fully eliminating VOCs. Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) analyses verified that the different ESSBRs were successfully synthesized from solution polymerized styrene-butadiene rubbers (SSBR). With the help of the reaction between epoxy groups and silicon hydroxyl without any VOC emission, nanosilica can be well dispersed in the rubber matrix when SSBR partially replaced by ESSBR which was proved by Payne effect and TEM analysis. Dynamic and static mechanical testing demonstrated that silica/ESSBR/SSBR/BR nanocomposites have better performance and no VOC emission compared with Bis-(γ-triethoxysilylpropyl)-disulfide (TESPD) modified silica/rubber nanocomposites. ESSBR is very hopeful to replace traditional coupling agent TESPD to get high properties silica/rubber nanocomposites with no VOCs emission.
This article presents a high-efficient thermal analysis methodology and outlines a set of useful design guidelines for high-power linear ultrasonic motors. A thermal network modeling technique is ...introduced to rapidly calculate the temperature rise for a typical high-power linear ultrasonic motor with a V-shaped stator. First, a six-terminal equivalent circuit for Langevin piezoelectric transducer considering the prestress bolt loss and all three losses in piezoelectrics is proposed to calculate the stator loss. Then, the calculated losses along with the friction loss are used as inputs into the developed thermal network model to calculate the temperature rise of critical parts of the motor. Furthermore, an analytical mechanical model combined with the proposed thermal network is established to calculate the temporal-spatial distribution of the stator thermal stress for evaluating its fatigue under the heating-up process. Finally, some experimental measurements and finite-element simulations are conducted to validate the theoretical analyses.
Mastitis is a common disease in dairy cows that is mostly caused by E. coli, and it brings massive losses to the dairy industry. N6-Methyladenosine (m6A), a methylation at the N6 position of RNA ...adenine, is a type of modification strongly associated with many diseases. However, the role of m6A in mastitis has not been investigated. In this study, we used MeRIP-seq to sequence the RNA of bovine mammary epithelial cells treated with inactivated E. coli for 24 h. In this in vitro infection model, there were 16,691 m6A peaks within 7066 mRNA transcripts in the Con group and 10,029 peaks within 4891 transcripts in the E. coli group. Compared with the Con group, 474 mRNAs were hypermethylated and 2101 mRNAs were hypomethylated in the E. coli group. Biological function analyses revealed differential m6A-modified genes mainly enriched in the MAPK, NF-κB, and TGF-β signaling pathways. In order to explore the relationship between m6A and mRNA expression, combined MeRIP-seq and mRNA-seq analyses revealed 212 genes with concomitant changes in the mRNA expression and m6A modification. This study is the first to present a map of RNA m6A modification in mastitis treated with E. coli, providing a basis for future research.
To improve the resistance to hydrogen embrittlement and hydrogen permeation performance of vanadium (V) membranes, first-principles calculations were employed to study the stability, dissolution, and ...diffusion properties of H in transition metal (M = Mo, W)-doped V membranes, as well as their mechanical and thermodynamic properties, as alternative candidates for H2 separation. Our results revealed that the doping percentage of Mo/W alloying can significantly improve the mechanical and thermodynamic properties of pure V. The most stable location for adsorbed H atoms is the tetrahedral interstitial site (TIS) in the body-centered cubic structure of the V1-xMx (x = 0.0625, 0.125, 0.1875, and 0.25) alloys. Additionally, the hydrogen migration path should preferentially follow TIS → nearest-neighbor TIS. An M content of 0.25 yields the best anti-hydrogen embrittlement and the highest hydrogen-diffusion properties. The addition of individual Mo or W as doping elements into the V-based system greatly enhanced the hydrogen diffusion coefficient, and the addition of both Mo and W significantly improved the anti-hydrogen embrittlement of V-based alloys. Our results also showed that hydrogen concentration markedly influenced the solubility and diffusivity of hydrogen in V-based alloy membranes. These results provide a basis for the design of V-based alloy hydrogen permeation membranes.
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•Mo/W-doped V solid solutions present a better mechanical strength.•H-diffusion coefficient of V metal is greatly improved by 25 at.% Mo/W doping.•V0.5Mo0.25W0.25 solid solution has a better resistance to H-embrittlement.
The variation of polar vortex intensity is a significant factor affecting the atmospheric conditions and weather in the Northern Hemisphere (NH) and even the world. However, previous studies on the ...prediction of polar vortex intensity are insufficient. This paper establishes a deep learning (DL) model for multi-day and long-time intensity prediction of the polar vortex. Focusing on the winter period with the strongest polar vortex intensity, geopotential height (GPH) data of NCEP from 1948 to 2020 at 50 hPa are used to construct the dataset of polar vortex anomaly distribution images and polar vortex intensity time series. Then, we propose a new convolution neural network with long short-term memory based on Gaussian smoothing (GSCNN-LSTM) model which can not only accurately predict the variation characteristics of polar vortex intensity from day to day, but also can produce a skillful forecast for lead times of up to 20 days. Moreover, the innovative GSCNN-LSTM model has better stability and skillful correlation prediction than the traditional and some advanced spatiotemporal sequence prediction models. The accuracy of the model suggests important implications that DL methods have good applicability in forecasting the nonlinear system and vortex spatial–temporal characteristics variation in the atmosphere.
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