168 research outputs found
Variable-parameter double-power reaching law sliding mode control method
To solve the problem of the slow convergence rate of the reaching law and the chattering problems in the dynamic response in the sliding mode control, an improved double-power sliding mode reaching law is proposed. The reaching law is adjusted by changing the magnitude of the power terms adaptively at different stages of the system approach process, and the convergence speed of the dynamic response process is greatly improved. Its existence, accessibility and stability are proven by theory. The simulation results show that the improved double-power reaching law is faster than the double-power reaching law and the fast power reaching law. When there is uncertainty in the system, the system state and its derivatives can rapidly converge to the neighbor-hood of the equilibrium zeros. In the presence of time-varying perturbations of the two-order system, the sliding mode control system based on the improved double-power sliding mode reaching law has higher tracking precision of the given signal and differential signal and effectively reduces the high-frequency chattering phenomenon of the control input signal
A facile direct route to N-(un)substituted lactams by cycloamination of oxocarboxylic acids without external hydrogen
Lactams are privileged in bioactive natural products and pharmaceutical agents and widely featured in functional materials. This study presents a novel versatile approach to the direct synthesis of lactams from oxocarboxylic acids without catalyst or external hydrogen. The method involves the in situ release of formic acid from formamides induced by water to facilitate efficient cycloamination. Water also suppresses the formation of byproducts. This unconventional pathway is elucidated by a combination of model experiments and density functional theory calculations, whereby cyclic imines (5âmethylâ3,4âdihydroâ2âpyrrolone and its tautomeric structures) are found to be favorable intermediates toward lactam formation, in contrast to the conventional approach encompassing cascade reductive amination and cyclization. This sustainable and simple protocol is broadly applicable for the efficient production of various Nâunsubstituted and Nâsubstituted lactams
PO-256 Influences of Exercise on Circulating Irisin in Overweight or Obese Individuals: a system review
Objective Irisin is a newly identified myokine, which is mainly secreted by skeleton muscle, adipose and cerebellar. It is shown to be related to some physiology process. The aim of this study is to evaluate the influence of exercise on circulating irisin concentrations in overweight or obese individuals
Methods Searches were performed on nine online electronic databases including PubMed, EMbase, The Cochrane Library, web of science, Ebsco, CNKI, VIP, CBM and Wan-Fang Data databases. The search items were irisin, fibronectin type â
ą domain-containing protein 5, FNDC5, exercise, training, physical activity, obesity, overweight, obese, body mass index, BMI, adiposity and fat. Randomized controlled trials (RCT) or clinical controlled trials about the effect of exercise on circulating irisin concentrations in overweight or obese individuals in English or Chinese were eligible for the study. The trials compare exercise intervention with no intervention, or combined interventions of exercise and other with other intervention(s), and the exercise intervention is not one acute time. Besides, the trial objects belong to overweight or obese regardless of the judgementâs indicator. According to the criteria, the data extracted by two research independently. If there was disagreement, discussion between all the authors were used to settle. The risk of bias among the included studies was assessed by the Cochrane Collaboration Risk-of-Bias tool, which consists of seven domains and each one was judged to âunclear riskâ âlow riskâ, or âhigh riskâ following the recommendations detailed of the Cochrane handbook. Lastly an analysis about the final studies was done.
Results The search identified a total of 855 possible articles. Of those, 364 were removed as duplicates, and the remaining 491 were screened for the titles and abstracts. The full-texts of 56 trials were retrieved to assess for eligibility. After the evaluation, four articles of RCTs were retained for the final system review from the year of 2015 to 2017, producing 6 study estimates. The assessments class of methods quantality of them are A. All the research subjects are more than 18 years old, and in one study subjects are men, men and women in two, women in three. The types of exercise intervention are dissimilar, such as strengthen or endurance exercise (including high intensity interval training, HIIT). In the duration of exercise, three studies are 8 weeks, and two for 12 weeks, one for 24 weeks. In circulating irisin, the detection methods of all is enzyme-linked immunosorbent assay, and three are in plasm, three in serum. Furthermore, the concentration unit in five studies is ng/ml, and one is ”g/ml. Bonefate suggests that aerobic exercise with the frequency of 3 times per week for 24 week maintains plasma FNDC5/irisin of middle-age obese men, same as 8 weeks aerobic exercise for overweight/obese adults by Kim, but three is an opposite result from Wu, which proved that aerobic exercise of twelve weeks ascends serum irisin of young obese women. HIIT of eight or twelve weeks ascends serum irisin in sedentary obese women or young obese women according to Tofighi or Wu suggestion. Moreover, resistance exercise of 8 weeks significantly increases plasma irisin of overweight/obese adults From Kimâs study.
Conclusions The study about effect of exercise on circulating irisin levels in overweight or obese individuals is not sufficient to come to a positive result, although the quality assessments of current evidences are high. Basing on the available literatures, exercise can maintain or improve circulating irisin levels in overweight or obese individuals. The effect needs to be illustrated by further RCTs with large sample size.
 
A pre-protection method for a pipe-jacking channel over shield tunnels
With the improvement of the planning level of underground space, the location of the planned under-crossing tunnel can be known in advance when constructing the upper-span tunnel. Therefore, pre-protection measures can be taken in advance during the construction of the upper-span tunnel. A new pre-protection method of a pipe-jacking channel was proposed to reduce the adverse effects of under-crossing shield tunnels. Numerical simulations of different pre-protection schemes were carried out using the finite element method to analyze its deformation control effect. The simulation results show that the deformation control effect of the gantry reinforcement scheme is the most significant. It is shown that the displacement of the pipe-jacking channel is more significantly suppressed with pre-protection measures than without preventive protection measures. The vertical displacement curve of the pipe-jacking channel exhibits a âWâ shape after the construction of the double-lane shield underpass. By comparing the three different working conditions, it is found that the maximum vertical displacement and surface settlement of the pipe-jacking channel greatly reduced the gantry reinforcement pre-protection. Compared with Case 3, the effect of the pre-protection measures adopted in Case 2 was less obvious, which indicated that the form of the pre-protection had an important influence on controlling the deformation of the pipe-jacking channel
Growth inhibition of mouse embryonic stem (ES) cells on the feeders from domestic animals
Mouse embryonic stem cells (mESCs) can be propagated in vitro on the feeders of mouse embryonic fibroblasts. In this study, we found growth inhibition of mESCs cultured on embryonic fibroblast feeders derived from different livestock animals. Under the same condition, mESCs derived from mouse embryonic fibroblast feeders were seen on the mass-like colonies and round or oval images, and more significant growth in the total number of colonies (p<0.05) and viable cells in the colonies (p<0.01) than that from goat embryonic fibroblast feeders, and viable cells in the colonies (p<0.05) than that from porcine embryonic fibroblast feeders. The feeders from bovine embryonic fibroblasts also reduced viable cells in the colonies, but were not significantly different in the total number of colonies and viable cells in the colonies with mouse embryonic fibroblast feeders. mESCs on the different embryonic fibroblast feeders were expressed as stem cell-specific markers Oct 4 and stage-specific embryonic antigen 1 (SSEA 1). Here, our results indicate that the feeders from goat, porcine and bovine embryonic fibroblasts inhibit the proliferation of mESCs.Key words: Domestic animals, feeders, mouse embryonic stem cells (mESCs), growth
Screening and evaluating of long noncoding RNAs in the puberty of goats
GO analysis of predicted targets of lncRNAs in trans. (XLS 1551ĂÂ kb
Characterization of Bovine Induced Pluripotent Stem Cells by Lentiviral Transduction of Reprogramming Factor Fusion Proteins
Pluripotent stem cells from domesticated animals have potential applications in transgenic breeding. Here, we describe induced pluripotent stem (iPS) cells derived from bovine fetal fibroblasts by lentiviral transduction of Oct4, Sox2, Klf4 and c-Myc defined-factor fusion proteins. Bovine iPS cells showed typical colony morphology, normal karyotypes, stained positively for alkaline phosphatase (AP) and expressed Oct4, Nanog and SSEA1. The CpG in the promoter regions of Oct4 and Nanog were highly unmethylated in bovine iPS cells compared to the fibroblasts. The cells were able to differentiate into cell types of all three germ layers in vitro and in vivo. In addition, these cells were induced into female germ cells under defined culture conditions and expressed early and late female germ cell-specific genes Vasa, Dazl, Gdf9, Nobox, Zp2, and Zp3. Our data suggest that bovine iPS cells were generated from bovine fetal fibroblasts with defined-factor fusion proteins mediated by lentivirus and have potential applications in bovine transgenic breeding and gene-modified animals
Dynamic resilient modulus of subgrade silty clay for heavy-haul railway: an experimental investigation and the predicted method
A large-scale series of cyclic triaxial tests were conducted to explore the evolution of the dynamic resilient modulus of silty clay for the heavy-haul railway subgrade. A novel loading sequence for measuring the dynamic resilient modulus was established, which characterized the dynamic stress state of the subgrade induced by the heavy-haul train load. In the experimental investigation, the deviatoric stresses, confining stress, initial moisture content, and compaction degree were considered as variables, and the effects of the aforementioned variables were evaluated quantitatively. The experimental results showed that the dynamic resilient modulus was negatively related to deviatoric stresses and initial moisture content, where the average decreased rates were 14.65% and 27.79% with the increase in deviatoric stresses from 60Â kPa to 150Â kPa and increase in the initial moisture content from 9.8% to 15.8%, respectively. Furthermore, the dynamic resilient modulus was positively related to confining stress and compaction degree, where the average increased rates were 23.25% and 27.48% with the increase in confining stress from 20Â kPa to 60Â kPa and increase in compaction degree from 0.91 to 0.95. To provide a better application, the two high-accuracy predicted methods were established through the empirical model and artificial neural network approach including the aforementioned variables. This study can provide useful guidelines for the effective and safe design of the heavy-haul railway subgrade filled with silty clay
Top executive leadersâ compassionate actions: an integrative framework of compassion incorporating a confucian perspective
This paper sets out to develop a theoretical framework for understanding compassion. It contributes to the research of compassion from an indigenous theory perspective to complement the Western theory of this important topic. We do this by adopting self-cultivation, a Confucian indigenous theoretical perspective based on xin (mind-heart) to guide our grounded study and thus develop an integrative framework. With an analysis based on extensive interviews with top executive leaders in Chinese enterprises, we thus show that (1) integrating compassion and self-cultivation enriches our understanding of the moral growth of compassion; (2) compassion affects performance outcomes at the individual, relational, and organizational levels; and (3) self-cultivation and compassion have an ultimate interaction effect on organizational performance outcomes
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