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The shield type temporary support robot is an important component of the intelligent excavation robot system for large section roadways that adapts to the coexistence of dirt and debris. Its main function is to provide a safe and reliable workspace for achieving 'parallel excavation and support' operations. In order to enhance the safe and stable support of the shield type temporary support robot for surrounding rock during its pushing and driving process, based on the structure, working environment, and operational requirements of the shield type temporary support robot, a mathematical model of its pushing amount and support force during pressurized driving, as well as a dynamic model of pressurized driving, are established. A hydraulic control system for the shield type temporary support robot driving under pressure is designed. The system mainly consists of a support hydraulic system and a driving hydraulic system. During static support, the support hydraulic system needs to constantly output a support force greater than the weight of the upper shield body itself, and the driving hydraulic system is in standby mode. When driving under pressure, the support hydraulic system and the driving hydraulic system work simultaneously, ensuring that the temporary support robot 'reducing stress without leaving the roof' while steadily moving forward with the roof under pressure at all times. A precise control method for shield type temporary support robot driving under pressure based on fuzzy PID is proposed. The pressure and displacement signals of the temporary support robot are collected in real time by displacement sensors integrated on the displacement cylinder and pressure sensors in the hydraulic circuit. The signals are used to reflect the changes in support force and driving displacement during the temporary support robot's driving under pressure. Based on the error and error rate of the support force and displacement, the fuzzy PID algorithm is used to modify the control parameters of the support force and displacement, achieving reliable control of driving under pressure based on the fuzzy PID algorithm. Both simulation and experimental results show that the effect of fuzzy PID control is superior to traditional PID control. Under fuzzy PID control, the relative error of support force during the pushing and driving process of the shield type temporary support robot is less than 1%, and the driving displacement error is less than 2 mm. Moreover, the response speed of support force and pushing amount control is fast, ensuring the safe and stable support of the surrounding rock during the pushing and driving process.

Abstract Background A better understanding of how the prevalence of hearing loss and its associated factors change over time could help in developing an appropriate program to prevent the development of hearing loss. Methods Population-representative cross-sectional data from the United States National Health and Nutrition Examination Survey (NHANES) were used to estimate the trends in the prevalence of hearing loss among adults in the USA over the period 1999–2018. A total of 15,498 adult participants aged 20 years or older had complete audiometric examination data. Logistic regression was employed to evaluate the trend in hearing loss; weighted Rao-Scott χ2 tests and univariate logistic regression analyses were used to examine the association between hearing loss and relevant factors. Results The overall hearing loss prevalence in 1999–2018 was 19.1% 19.1 (95% CI, 18.0–20.2%). The prevalence of hearing loss decreased in cycles (P for trend 70 years the prevalence decreased from 79.9% (95% CI, 76.1–83.8%) in 2005–2006 to 64.5% (95% CI, 58.8–70.2%) in 2017–2018. Participants with hearing loss were likely to be older, male, non-Hispanic white, and to have not completed high school. Mild hearing loss was more prevalent among those aged 20–79 years; in those aged over 80 years the prevalence of moderate hearing loss exceeded that of mild loss. Among all otologically normal participants, hearing thresholds increased with age across the entire frequency range. Conclusions The prevalence of hearing loss in USA adults changed over the period 1999–2018. The trends observed provide valuable insight for making public health plans and allocating resources to hearing care. Further investigation is necessary to monitor hearing loss and its potential risk factors.

Abstract Background This study aimed to screen and validate noise-induced hearing loss (NIHL) associated single nucleotide polymorphisms (SNPs), construct genetic risk prediction models, and evaluate higher-order gene-gene, gene-environment interactions for NIHL in Chinese population. Methods First, 83 cases and 83 controls were recruited and 60 candidate SNPs were genotyped. Then SNPs with promising results were validated in another case-control study (153 cases and 252 controls). NIHL-associated SNPs were identified by logistic regression analysis, and a genetic risk model was constructed based on the genetic risk score (GRS), and classification and regression tree (CART) analysis was used to evaluate interactions among gene-gene and gene-environment. Results Six SNPs in five genes were significantly associated with NIHL risk (p

Objective: This study aimed to realize the fast and accurate sorting of citrus color. Methods: An online color detection and grading system of citrus based on machine vision was designed in this study. The system is composed of feeding unit, chain conveying mechanism, image acquisition system and fruit dividing unit. The industrial camera which was combined with the rolling mechanism was used to uniformly capture 50~60 frames of images for obtaining the complete surface information of citrus. The non-destructive testing software preprocessed each frame of images acquired in real time to obtain the two-dimensional coloring ratio, which is dynamically tracked and stored. The arithmetic mean value of two-dimensional coloring ratio was taken to reduce the influence of the repeated areas on the coloring rate calculation of citrus surface, and finally the calculated coloring rate was discriminated and graded. Results: The experimental results showed that when the transmission speed was 6 s-1, the maximum error of citrus coloring proportion calculated by the system was 5%, and the sorting accuracy rate was 90.54%. Conclusion: The system can meet the needs of fast and accurate sorting of citrus color.

Polyether imide (PEI) flat ultrafiltration membrane was prepared by immersion precipitation phase inversion method. The effects of polymer PEI concentration and additive polyvinylpyrrolidone (PVP) concentration on the structure and properties of membrane were investigated. In order to improve the solvent resistance of ultrafiltration membrane, hexamethylenediamine (HDA) was used for chemical crosslinking, and the difference of membrane performance under different crosslinking time was studied. The results show that the flux of the crosslinked membrane is effectively improved without reducing the membrane separation performance compared with the uncrosslinked ultrafiltration membrane. Under the operating pressure of 0.1 MPa, the flux of pure water is increased from 667.1 L/(m2·h) to 1126.1 L/(m2·h), while the rejection rate of 1.0 g/L BSA solution remains above 97%. After soaking in six different solvents for 48 h, it was found that the uncrosslinked membrane is completely dissolved in N, N-dimethylformamide (DMF), while the crosslinked membrane still maintains a good membrane morphology with an adsorption capacity of 0.86 g/g. The adsorption capacity in ethanol, isopropanol, n-hexane and 1 mol/L HCl solution is smaller than that of the uncrosslinked membrane, but is increased in 1 mol/L NaOH solution, which indicates that the prepared crosslinked membrane has good solvent resistance and strong acid resistance, but the strong alkali resistance becomes worse.

Block collapse or sliding is one of the main failure modes of rock slope engineering. Namely, block stability analysis plays a key role in rock slope engineering. Taking the Shenxianju rock slope in Xianju County, Zhejiang Province as the research background, this paper mainly conducts the stability analysis and visualization of rock blocks. A new method for fitting structural planes and free faces is proposed based on the linear regression method and the non-uniform rational B-spline method. Then, based on the coordinate projection method, the method for calculating the stability coefficients of the single sliding surface and double sliding surface blocks is proposed. Finally, the unmanned aerial vehicle (UAV) measurement technology combined with the coordinate projection method is used to develop a CPG program using MATLAB, which can be adopted in the stability analysis of planar polyhedron blocks and curved blocks in rock slope engineering. This program enables the spatial representation and visualization of structural planes, free faces and unstable blocks. Engineering practice shows that the new proposed method is effectively applicable to engineering geological disasters, such as rockfall and collapse. The results of the program calculation are basically consistent with those of the coordinate projection block theory, demonstrating that this method is reliable and the developed CPG program is feasible. This method is of vital significance in practical engineering since it can greatly improve the efficiency of block stability analysis.

Acute myeloid leukemia is a disorder characterized by abnormal differentiation of myeloid cells and a clonal proliferation derived from primitive hematopoietic stem cells. Interventions that overcome myeloid differentiation have been shown to be a promising therapeutic strategy for acute myeloid leukemia. In this study, we demonstrate that CRISPR/Cas9-mediated knockout of dihydroorotate dehydrogenase leads to apoptosis and normal differentiation of acute myeloid leukemia cells, indicating that dihydroorotate dehydrogenase is a potential differentiation regulator and a therapeutic target in acute myeloid leukemia. By screening a library of natural products, we identified a novel dihydroorotate dehydrogenase inhibitor, isobavachalcone, derived from the traditional Chinese medicine Psoralea corylifolia. Using enzymatic analysis, thermal shift assay, pull down, nuclear magnetic resonance, and isothermal titration calorimetry experiments, we demonstrate that isobavachalcone inhibits human dihydroorotate dehydrogenase directly, and triggers apoptosis and differentiation of acute myeloid leukemia cells. Oral administration of isobavachalcone suppresses subcutaneous HL60 xenograft tumor growth without obvious toxicity. Importantly, our results suggest that a combination of isobavachalcone and adriamycin prolonged survival in an intravenous HL60 leukemia model. In summary, this study demonstrates that isobavachalcone triggers apoptosis and differentiation of acute myeloid leukemia cells via pharmacological inhibition of human dihydroorotate dehydrogenase, offering a potential therapeutic strategy for acute myeloid leukemia.

A fixed-value mask algorithm for SMS4 was proposed in order to resist power analysis attack based SMS4.Firstly,an atomic mask algorithm of SMS4 was designed to resist against high-order power analysis attack based on the study of the structure of SMS4 algorithm,the intermediate variables were masked in the method.Secondly,pseudo-random fixed-value mask method（PFM） was proposed based on the above method,when its hardware implementation aiming at low power and less areas was considered about.Moreover,PFM has the ability to resist against high-order power analysis attacks when applied to the sensor node of special environment of communication.Finally,the experimental results show that the proposed algorithm has the ability to effectively resist second high-order differential power analysis attack without increasing much power and hardware resources.

OBJECTIVE: To comprehensively analyze the relationship between exposure to extremely low frequency electromagnetic fields (ELF-EMFs) and the development of female breast cancer. METHODS: Reports of case-control studies published from 1990 to 2010 were analyzed. The quality effect model was chosen to calculate total odds ratio (OR) depending on the data in studies and quality scores. Subgroup analyses were also performed by the situation of menopause, estrogenic receptor and exposure assessment respectively. RESULTS: For all 23 studies the OR was 1.07, 95% CI=1.02-1.13, for estrogen receptor positive subgroup,OR=1.11, 95% CI=1.03-1.20; for premenopausal subgroup, OR=1.11, 95% CI=1.00-1.23. The results of other subgroups showed no significant association between ELF-EMF and female breast cancer. CONCLUSION: ELF-EMFs might be related to an increased risk for female breast cancer, especially for premenopausal and ER+ females. However, it's necessary to undertake better epidemiologic researches to verify the association between ELF-EMF and female breast cancer due to the limits of current study, especially the one on exposure assessment.

Abstract Background Alternative splicing increases proteome diversity by expressing multiple gene isoforms that often differ in function. Identifying alternative splicing events from RNA-seq experiments is important for understanding the diversity of transcripts and for investigating the regulation of splicing. Results We developed Alt Event Finder, a tool for identifying novel splicing events by using transcript annotation derived from genome-guided construction tools, such as Cufflinks and Scripture. With a proper combination of alignment and transcript reconstruction tools, Alt Event Finder is capable of identifying novel splicing events in the human genome. We further applied Alt Event Finder on a set of RNA-seq data from rat liver tissues, and identified dozens of novel cassette exon events whose splicing patterns changed after extensive alcohol exposure. Conclusions Alt Event Finder is capable of identifying de novo splicing events from data-driven transcript annotation, and is a useful tool for studying splicing regulation.

Abstract We present a mixture model-based analysis for identifying differences in the distribution of RNA polymerase II (Pol II) in transcribed regions, measured using ChIP-seq (chromatin immunoprecipitation following massively parallel sequencing technology). The statistical model assumes that the number of Pol II-targeted sequences contained within each genomic region follows a Poisson distribution. A Poisson mixture model was then developed to distinguish Pol II binding changes in transcribed region using an empirical approach and an expectation-maximization (EM) algorithm developed for estimation and inference. In order to achieve a global maximum in the M-step, a particle swarm optimization (PSO) was implemented. We applied this model to Pol II binding data generated from hormone-dependent MCF7 breast cancer cells and antiestrogen-resistant MCF7 breast cancer cells before and after treatment with 17β-estradiol (E2). We determined that in the hormone-dependent cells, ~9.9% (2527) genes showed significant changes in Pol II binding after E2 treatment. However, only ~0.7% (172) genes displayed significant Pol II binding changes in E2-treated antiestrogen-resistant cells. These results show that a Poisson mixture model can be used to analyze ChIP-seq data.

Abstract Massively parallel pyrosequencing is a high-throughput technology that can sequence hundreds of thousands of DNA/RNA fragments in a single experiment. Combining it with immunoprecipitation-based biochemical assays, such as cross-linking immunoprecipitation (CLIP), provides a genome-wide method to detect the sites at which proteins bind DNA or RNA. In a CLIP-pyrosequencing experiment, the resolutions of the detected protein binding regions are partially determined by the length of the detected RNA fragments (CLIP amplicons) after trimming by RNase digestion. The lengths of these fragments usually range from 50-70 nucleotides. Many genomic regions are marked by multiple RNA fragments. In this paper, we report an empirical approach to refine the localization of protein binding regions by using the distribution pattern of the detected RNA fragments and the sequence specificity of RNase digestion. We present two regions to which multiple amplicons map as examples to demonstrate this approach.

The aim of this study is to investigate stress wave propagation in metal foams under high-speed impact loading. Three-dimensional Voronoi model is established to represent real closed-cell foam. Based on the one-dimensional stress wave theory and Voronoi model, a numerical model is developed to calculate the velocity of elastic wave and shock wave in metal foam. The effects of impact velocity and relative density of metal foam on the stress wave propagation in metal foams are explored respectively. The results show that both elastic wave and shock wave propagate faster in metal foams with larger relative density; with increasing the impact velocity, the shock wave propagation velocity increase, but the elastic wave propagation is not sensitive to the impact velocity.