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Due to space limitations, multi frequency multiple-input multiple-output (MIMO) antennas have strong coupling problems caused by small unit spacing. In order to solve the above problems, a mine high isolation tri-band MIMO antenna has been designed. By loading two L-shaped branches at both ends of a rectangular branch to form a trident monopole antenna, the antenna has tri-band features. Two trident monopole antenna units are placed symmetrically. A T-shaped branch is loaded on the metal floor between the two units. The opposite current generated by parasitic branches is used to offset the coupling current without branches. Two symmetrical rectangular slots are etched to suppress the mutual coupling caused by surface waves on the floor by changing the current distribution on the floor. The high isolation of the antenna throughout the entire band is achieved. The simulation results show that the antenna operates in frequency bands of 1.85-2.70, 3.24-3.99, 4.65-5.80 GHz, can effectively covering coal mines' underground WiMAX/WiFi/4G/5G NR operating band. The isolation of the antenna in three bands is greater than 20, 22, 22 dB, respectively. It is 11, 9, 10 dB higher than the isolation of the antenna before decoupling; The envelope correlation coefficient is less than 0.2, indicating good diversity performance. The antenna has stable gain variation within the operating band and good omnidirectional radiation features. This antenna has the advantages of simple and compact structure, easy processing, and low profile. It has a wide range of application scenarios in wireless communication in coal mines.

With the application of 5G technology in the coal mine, the signal interference between multiple systems becomes more and more intensive. This seriously affects the quality of data, voice and image communication. The coexistence of multiple systems in coal mine becomes increasingly prominent. To solve this problem, a multi-band microstrip antenna for mine is designed, which can work in WiMAX/WiFi/4G/5G NR band at the same time. Based on a planar monopole antenna, the antenna can work in multiple frequency bands in the mode of loading two L-shaped branches and loading an inverted L-shaped branch on the floor. The simulation results show that the antenna's middle, right and left branches produce 2.4, 3.5 GHz and 4.8 GHz resonance points respectively. The inverted L-shaped branch loaded on the floor provides 1.9 GHz resonance point. The antenna can work in three frequency bands, which are 1.88-2.73, 3.26-3.79 GHz and 4.7-5.9 GHz respectively. The antenna can effectively cover all the operating frequency bands of WiMAX/WiFi/4G/5G NR in coal mines. According to the antenna's peak gain and normalized pattern, the antenna has good gain performance and overall radiation performance in the required operating frequency band.

ObjectiveTo determine the risk factors associated with colorectal adenoma among the residents in Nanchang city， and provide scientific evidence for primary preventive measures against colorectal cancer.MethodsA matched case-control study was conducted. A total of 155 patients newly diagnosed with colorectal adenomas during 2018‒2019 were selected as cases， and 155 healthy persons attending the screening as controls. Both the case group and control group completed the questionnaires on the risk factors. Conditional logistic regression analysis was performed using SPSS 25.0.ResultsAge， gender， and educational level were used for match between case group and control group. Conditional multivariate logistic regression analysis showed that salted and dried food intake（OR=5.634， 95%CI：1.308‒24.256）， smoking（OR=3.266， 95%CI：1.419‒7.518）， passive smoking（OR=3.125，95%CI：1.415‒6.898）， and hyperlipidemia （OR=3.975， 95%CI：1.643‒9.618）were associated with higher risk of colorectal adenoma. In contrast， coarse grain intake ≥500 g/week （OR=0.377， 95%CI：0.177‒0.805） was a protective factor.ConclusionColorectal adenoma may be caused by multiple risk factors， particularly salted and dried food intake， smoking， passive smoking and hyperlipidemia. It warrants specific intervention to reduce the risk of colorectal adenoma.

Lithium–sulfur (Li–S) batteries are among the most promising new-generation energy storage devices due to their abundant reserves, low price, and high theoretical specific capacity (1675 mA h g−1). However, Li–S batteries still face challenges such as the "shuttle effect" and slow redox kinetic reactions during charging and discharging. Here, we report a covalent organic skeleton with a bisulfite (EB-COF:HSO3) modified separator, which is capable of mitigating the shuttle effect of polysulfide anions and accelerating Li–S transport. Specifically, negatively charged sulfate groups can inhibit identically charged polysulfide anions through electrostatic repulsion, thereby improving the cycling stability of the battery. At the same time, positively charged lithium ions are promoted to pass through the separator. As a result, the EB-COF:HSO3-modified separator exhibited excellent electrochemical performance at a current density of 1C, with an initial specific capacity of 968 mA h g−1, and maintained a capacity of 785 mA h g−1 after 500 cycles with a decay rate of only 0.04%. In comparison, EB-COF under the same conditions has an initial capacity of 813 mA h g−1 and a high decay rate of 0.12%. [ABSTRACT FROM AUTHOR]

Objectives: Asthma is a heterogeneous disease characterized by chronic airway inflammation. Huashanshen dripping pills (HSS) are commonly utilized for relieving asthma, relieving cough, and expelling phlegm. At present, the molecular mechanism against airway inflammation remains unclear. Methods: In this study, network pharmacology, molecular docking technology, and molecular dynamic simulation were used to predict the therapeutic pathways of HSS for asthma. The ovalbumin-induced mouse model was used to further validate the prediction by RT-qPCR, western blot, immunofluorescence, and related methods. Key findings: The findings indicate that HSS improves lung function and relieves lung inflammation by reducing inflammatory cell infiltration around the bronchus and reducing eosinophilic counts in bronchoalveolar lavage fluid (BALF). In addition, it lowers the levels of inflammatory cytokines and the expression levels of interleukin-4, interleukin-5, and interleukin-13 mRNA. HSS also inhibits the phosphorylation and nuclear translocation of NF-κB p65 protein. Conclusions: All results suggested that HSS can decrease airway inflammation in asthmatic mice by inhibiting NF-κB signaling pathway. This finding will shed light on how it can be used to treat asthma. [ABSTRACT FROM AUTHOR]

Disease recurrence perception plays a key role in disease management and subsequent disease recurrence prevention. However, there are no specific tools for assessing disease recurrence perception in patients with inflammatory bowel disease (IBD) characterized by alternating remission and recurrence. To develop and validate an instrument for measuring disease recurrence perception of patients with IBD, the study was conducted in two steps: (1) instrument development and (2) psychometric tests. A total of 623 patients with IBD participated in the study. The common sense model of illness self‐regulation (CSM) was used as a framework for instrument development. The administered version contained 48 items intended to be relevant to at least one of the six dimensions of the model. Based on preliminary analyzes, 12 items were deleted leaving 36 items for more detailed psychometric and factor analyzes. The Cronbach's alpha coefficient of the total 36‐item instrument was 0.915. The content validity indexes at item and scale levels were satisfactory. The test‐retest reliability of the total instrument was 0.870. Exploratory principal components analysis (n = 278) was used to identify six components congruent with intended CSM constructs that accounted for 62.6% of total item variance. Confirmatory factor analysis (n = 345) found acceptable fit for the six factor measurement model (χ2/df = 1.999, GFI = 0.846, NFI = 0.855, IFI = 0.922, TLI = 0.910, CFI = 0.921, RMSEA = 0.054). Overall, the DRPSIBD demonstrated satisfactory reliability and validity to warrant further development as a measure of disease recurrence perception of patients with IBD. [ABSTRACT FROM AUTHOR]

This paper proposes a three-step joint rate optimization method for intelligent reflecting surface (IRS)-assisted coal mine wireless communication systems. Different from terrestrial IRS-assisted communication scenarios, in coal mines, IRSs can be installed flexibly on the tops of rectangular tunnels to address the issues of signals being blocked and interfered with by mining equipment. Therefore, it is necessary to optimize the IRS deployment position, the transmit power and IRS phase shifts to achieve the maximum effective achievable rate at user stations equipped with the proposed system. However, due to the complex channel models of coal mines, the optimization problem of IRS deployment position is non-convex. To solve this problem, two auxiliary variables along with logarithmic operations and Taylor approximation are introduced. On this basis, a three-step joint rate optimization involving the transmit power, IRS phase shifts and IRS deployment position is proposed to maximize the effective achievable rates at the user station. The simulation results show that compared with other rate optimization schemes, the effective achievable rates at the user station using the proposed joint rate optimization scheme can be improved by approximately 12.32 % to 54.17 % for different parameter configurations. It is also pointed out that the deployment position of the IRS can converge to the same optimal position independent of the initial deployment position. Moreover, we investigate the effects of the roughness of the tunnel walls in a coal mine on the effective achievable rates at the user station, and the simulation results indicate that the proposed three-step joint rate optimization scheme performs better in the coal mine scenario regardless of the roughness. [ABSTRACT FROM AUTHOR]

The thinned and sparse beamforming for semicircular FDAs were investigated, where the excitation amplitudes were also considered in thinned semicircular FDAs, and only the elements' positions were incorporated into the sparse semicircular FDA. Firstly, the transmit–receive model was introduced to handle the inherent time-varying issue of FDA, followed by the thinned and sparse implementations successively. Note that three types of non-linearly varying frequency offsets (FO), i.e., log-FO, sin-FO, and tanh-FO, were adopted during the investigations. Under the same assumption that 50% of the elements should be saved, the sidelobe levels (SLLs) of the thinned semicircular -FDAs were reduced by 5.8 dB, 4.4 dB, and 4.4 dB, and the widths of the mainlobes were all widened by 3° in their angle dimension. Compared with the thinned semicircular FDAs, the phenomenon of mainlobe widening was alleviated in the sparse semicircular FDAs where the SLLs were reduced by 2.2 dB, 3.7 dB and 3.5 dB, and the mainlobes' widths in the angle dimension were widened by 1°, 0° and 1°, respectively. It should be highlighted that the sparse semicircular FDA with sin-FO did not broaden the mainlobe in the angle dimension. Therefore, it can be concluded that a sparse semicircular FDA is superior over a thinned semicircular FDA, since it can reduce the same cost with a higher array resolution. [ABSTRACT FROM AUTHOR]