3,806 research outputs found
Signature functions of knots
The signature function of a knot is an integer-valued step function on the
unit circle in the complex plane. Necessary and sufficient conditions for a
function to be the signature function of a knot are presented.Comment: 4 page
Effects of electron beam radiation on trait mutation in azuki bean (Vigna angularisi)
Dry seeds of azuki bean (Vigna angularisi), Jingnong 6 and Hebei 801 varieties were irradiated by electron beam of 100, 300, 600, 700 and 900 Gy, respectively. Mutations of leaf shape and color, seed size and shape, trailing, more branching, dwarfing, early or late flowering time and high yield were created in M2 and M3 generations. There were richest variations in Jinnong 6 treated with 600 Gy. Heibei 801 was more sensitive to electron beam radiation than Jingnong 6; more mutation types were produced at 100, 300 and 600 Gy. The pod number per plant, seed number and yield per plant of Jinnong 6 displayed a strikingly negative correlation to radiation dose, while the pod length, pod width, and 100-seeds weight of progenies from Hebei 801 had a significantly negative correlation with the radiation dose, but pod number per plants showed significantly positive correlation. Few of the normal phenotype plant in M2 generation derived mutants of new leaf yellowing, narrow leaf, clustering flower and leaf, kidney or sword leaf in M3 generation. Mutants of kidney and sword leaf, early flowering time from M2 generation could be stably inherited in M3 generation.Keywords: Azuki bean (Vigna angularisi), electron beam radiation, trait mutatio
MeDReaders: a database for transcription factors that bind to methylated DNA
Understanding the molecular principles governing interactions between transcription factors (TFs) and DNA targets is one of the main subjects for transcriptional regulation. Recently, emerging evidence demonstrated that some TFs could bind to DNA motifs containing highly methylated CpGs both in vitro and in vivo. Identification of such TFs and elucidation of their physiological roles now become an important stepping-stone toward understanding the mechanisms underlying the methylation-mediated biological processes, which have crucial implications for human disease and disease development. Hence, we constructed a database, named as MeDReaders, to collect information about methylated DNA binding activities. A total of 731 TFs, which could bind to methylated DNA sequences, were manually curated in human and mouse studies reported in the literature. In silico approaches were applied to predict methylated and unmethylated motifs of 292 TFs by integrating whole genome bisulfite sequencing (WGBS) and ChIP-Seq datasets in six human cell lines and one mouse cell line extracted from ENCODE and GEO database. MeDReaders database will provide a comprehensive resource for further studies and aid related experiment designs. The database implemented unified access for users to most TFs involved in such methylation-associated binding actives. The website is available at http://medreader.org/
Milling stability prediction based on the hybrid interpolation scheme of the Newton and Lagrange polynomials
The stability lobe diagram (SLD) is commonly used to determine the suitable cutting parameters of the machining system in order to achieve a chatter-free machining process. An improved full-discretization method (FDM) is proposed to predict the SLD based on the hybrid interpolation scheme of the Newton and Lagrange polynomials. In order to solve the SLD, a third-order Newton polynomial is employed to interpolate the state term of the physical space equation of the system. Meanwhile, to investigate the influence of the interpolation order on predicting the SLD, the delayed term is estimated using the Lagrange polynomials of orders one to four successively. Subsequently, after constructing the transition matrix, a series of calculation for the stability prediction are carried out by applying Floquet theory. The calculated results from these constructed methods demonstrate that the FDM with a second-order Lagrange polynomial is optimal, and further has better computational performance compared with some existing discretization methods. Lastly, the influences of the dynamic parameters on chatter stability are analyzed based on the proposed FDM. When the stiffness and damping ratio increase, the limit cutting depth will be enhanced. The increasing natural frequency not only causes an obvious shift of the lobes to the right, but also raises the limit cutting depth to some extent. These theoretical analyses can guide the prediction and improvement of the chatter stability of a machining system
Differential Effects of Anxiety on Internet Gaming Disorder: A Large-Scale Cross-Sectional Survey
BackgroundInternet gaming disorder (IGD) has become a serious public health problem in East Asia, and studies have reported IGD to be significantly associated with anxiety, but no causal relationship between the two has yet been demonstrated. Children are at high risk of developing IGD, however, previous studies have principally focused on the condition in adults and adolescents and reported non-clinical samples. A large-scale survey is needed to research and evaluate IGD and anxiety in children and adolescents to understand the current situation of IGD in children and explore the impact of IGD on anxiety.MethodsA cross-sectional study using an online questionnaire was conducted between March 1 and July 31, 2021. A total of 10,479 school children and adolescents in the western provinces of China were selected by convenience sampling. A questionnaire was used to collect data anonymously. The questionnaire covered IGD and the Revised Children's Manifest Anxiety Scale (RCMAS). Welch's ANOVA Test and Games-Howell test were used to test for differences in anxiety levels between IGD groups. Poisson regression analysis was used to further investigate the key predictors of IGD.Results3.2% of participants (n = 334) (95% CI: 2.9–3.2%) were classified as at high risk of presenting with IGD, 71.1% (n = 7,454) (95% CI: 70.3–72.0%) were classified as low-risk players, and 25.7% (n = 2,691) (95% CI: 24.9–26.5%) were classified as non-gaming. The average RCMAS score was (7.18 ± 7.534). The high-risk group had a higher total score RCMAS, as well as scoring higher in its three dimensions. Regression analysis using gender, age, and total RCMAS score as independent variables, and risk of IGD as a dependent variable showed that the odds ratio (OR) for gender was 2.864 (95% CI: 2.267–3.618), and the OR for total RCMAS score was 1.101 (95% CI: 1.087–1.114). The OR for age was not statistically significant.ConclusionAnxiety was a predictor of IGD, with statistically significant group differences in total anxiety, as well as the dimensions of physiological anxiety, social correlation, and sensitivity. The timely assessment of anxiety in children and adolescents, training social skills, and facilitating effective integration into society could be effective ways of reducing the incidence and impact of IGD
Corrigendum: Differential effects of anxiety on internet gaming disorder: A large-scale cross-sectional survey
A prognostic model based on DNA methylation-related gene expression for predicting overall survival in hepatocellular carcinoma
BackgroundHepatocellular carcinoma (HCC) continues to increase in morbidity and mortality among all types of cancer. DNA methylation, an important epigenetic modification, is associated with cancer occurrence and progression. The objective of this study was to establish a model based on DNA methylation risk scores for identifying new potential therapeutic targets in HCC and preventing cancer progression.MethodsTranscriptomic, clinical, and DNA methylation data on 374 tumor tissues and 50 adjacent normal tissues were downloaded from The Cancer Genome Atlas–Liver Hepatocellular Carcinoma database. The gene expression profiles of the GSE54236 liver cancer dataset, which contains data on 161 liver tissue samples, were obtained from the Gene Expression Omnibus database. We analyzed the relationship between DNA methylation and gene expression levels after identifying the differentially methylated and expressed genes. Then, we developed and validated a risk score model based on the DNA methylation-driven genes. A tissue array consisting of 30 human hepatocellular carcinoma samples and adjacent normal tissues was used to assess the protein and mRNA expression levels of the marker genes by immunohistochemistry and qRT-PCR, respectively.ResultsThree methylation-related differential genes were identified in our study: GLS, MEX3B, and GNA14. The results revealed that their DNA methylation levels were negatively correlated with local gene expression regulation. The gene methylation levels correlated strongly with the prognosis of patients with liver cancer. This was confirmed by qRT-PCR and immunohistochemical verification of the expression of these genes or proteins in tumors and adjacent tissues. These results revealed the relationship between the level of relevant gene methylation and the prognosis of patients with liver cancer as well as the underlying cellular and biological mechanisms. This allows our gene signature to provide more accurate and appropriate predictions for clinical applications.ConclusionThrough bioinformatics analysis and experimental validation, we obtained three DNA methylation marker: GLS, MEX3B, and GNA14. This helps to predict the prognosis and may be a potential therapeutic target for HCC patients
Effect Analysis of High-efficiency Dust-free Cleaning Screen in Grain Cleaning
In order to effectively resolve the conflicts between environmental protection,output and benefit during grain cleaning,the vibration screening,specific gravity air separation,cyclone separation,pulse dust removal,closed-loop air circulation and other dust removal technologies are integrated.Efficient dust-free cleaning screens are developed.To achieve effective impurity removal,the problems of excessive dust concentration in grain depots and enterprises’ grain processing and cleaning sites are aimed to be solved.Field tests on the grain depots show that the average impurity content of the grain can be controlled under 0.7% after cleaning,and the dust suppression effect is as follows:dust concentration at 5 m of the operation range lower than 30 mg/m³,15 m lower than 20 mg/m³ while 25 m lower than 10 mg/m³.Therefore,the cleaning effect and dust removal effect are better than common cleaning mechine
Effects of 8-Week Hatha Yoga Training on Metabolic and Inflammatory Markers in Healthy, Female Chinese Subjects: A Randomized Clinical Trial
We aimed to determine the effects of an 8 wk Hatha yoga training on blood glucose, insulin, lipid profiles, endothelial microparticles (EMPs), and inflammatory status in healthy, lean, and female Chinese subjects. A total of 30 healthy, female Chinese subjects were recruited and randomized into control or yoga practice group. The yoga practice included 8 wks of yoga practice (2 times/wk) for a total of 16 times. Fasting blood samples were collected before and after yoga training. Plasma was isolated for the measurement of lipid profiles, glucose, insulin, EMPs, and inflammatory cytokines. Whole blood was cultured ex vivo and stimulated with lipopolysaccharide (LPS) and Pam3Cys-SK4. Peripheral blood mononuclear cells (PBMCs) were isolated for the measurement of TLR2 and TLR4 protein expression. Yoga practice significantly reduced plasma cholesterol, LDL-cholesterol, insulin levels, and CD31+/CD42b− EMPs. Cultured whole blood from the yoga group has reduced proinflammatory cytokines secretion both at unstimulated condition and when stimulated with Pam3Cys-SK4; this might be associated with reduced TLR2 protein expression in PBMCs after yoga training. Hatha yoga practice in healthy Chinese female subjects could improve hallmarks related to MetS; thus it can be considered as an ancillary intervention in the primary MetS prevention for the healthy population. This trial is registered with ChiCTR-IOR-14005747
Development of a toolholder with high dynamic stiffness for mitigating chatter and improving efficiency in face milling
The toolholder featuring large ratio of length to diameter and variable corss-sections is required to achieve some special machining tasks in face milling operation, whereas the chatter phenomenon can easily occur attributing to the weak dynamic characteristic of the toolholder. This paper developed a novel toolholder which possessed high dynamic performance and was able to mitigate the chatter and improve material removing rate (MRR) simultaneously. The relationship between dynamic property of cutter with its modal characteristics was theoretically investigated from the built dynamic model of face milling operation. Based on the above findings, a novel toolholder was designed to increase the dynamic stiffness of the cutter, whose geometrical parameters and corresponding materials were optimized and selected. After manufacturing and detecting, the stability and machining conditions of the new toolholder were validated and amended with the aid of transfer function, milling forces and acceleration signal responses obtained from the tool point dynamics test and milling experiments respectively. As demonstrated in the experimental results, comparing with the conventional toolholder, the dynamic stiffness of the developed toolholder was increased by about 3.75 times, expanding significantly the stability frontier. The corresponding MRR with 2.81 times was achieved without increasing the machining response amplitudes
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