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The objective of this study was to investigate the effect of addition of four different lignocellulose (water-treated corn straw, water-treated xylosma sawdust, alkali-treated corn straw and alkali-treated xylosma sawdust) on the production and antioxidant activity of exopolysaccharides by Lentinula edodes. To evaluate the antioxidant activity of polysaccharides, the analyses of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity, lipid peroxidation inhibition rate and erythrocyte hemolysis inhibition rate were carried out. The result clearly indicated that the exo-polysaccharide production and antioxidant activity by L. edodes mycelium was enhanced in varying degrees via the decomposition of lignocellulose. The yield of exo-polysaccharide in alkali-treated corn straw group was the highest (0.351 g/L), which was 31.06% higher than that in control group after 5 days of submerged fermentation. High DPPH radical scavenging activity was observed in water-treated xylosma sawdust group, which decreased with the extension of fermentation time (23.15%-44.06%). Alkali-treated groups performed better than water-treated groups in terms of lipid peroxidation inhibitory activity. As for hemolysis inhibition activity toward erythrocytes, xylosma sawdust groups showed stronger oxidation resistance than corn straw groups.

A large number of RNA molecules are transported over long-distance between shoots and roots via phloem in higher plants. Mobile RNA signals are important for plants to tackle abiotic stresses. Shoot-derived mobile RNAs can be involved in the response to different developmental or environmental signals in the root. Some environmental conditions such as climate change, water deficit, nutrient deficiency challenge modern agriculture with more expeditious abiotic stress conditions. Root architecture determines the ability of water and nutrient uptake and further abiotic stress tolerance, and shoot tissue also determines the balance between shoot-root relationship in plant growth and adaptations. Thus, it is necessary to understand the roles of shoot-derived RNA signals and their potential function in roots upon abiotic stresses in the model plants (Arabidopsis thaliana and Nicotiana benthamiana) and agricultural crops. In this review, we summarize the so-far discovered shoot-derived mobile RNA transportation to the root under abiotic stress conditions, e.g. drought, cold stress and nutrient deficiencies. Furthermore, we will focus on the biological relevance and the potential roles of these RNAs in root development and stress responses which will be an asset for the future breeding strategies.

Directed evolution methodologies have been used as promising strategies for improving the catalytic properties of many existing enzymes. In the presented work, this approach was applied to improve the enzyme activity of l -asparaginase I obtained from Bacillus megaterium H-1. After two rounds of error-prone polymerase chain reaction (epPCR) and two generations of sequential DNA shuffling, all of 5 different mutants showed a significant increase in the enzyme activity of l -asparaginase I, ranging from 6.27 to 22.78 IU/mL. Among these mutants, D-9B and DD-12G displayed the relatively high catalytic activity, which were 20.22-fold and 21.33-fold higher than the wild-type enzyme (WT), respectively. Furthermore, the catalytic efficiency (kcat/Km) of D-9B and DD-12G were also improved, which were 132.73 min−1mM−1 and 146.39 min−1mM−1, respectively, in comparison to that of WT (3.39 min−1mM−1). In addition, mutant DD-12G showed tolerance toward wider range of pH values and higher temperatures than its WT counterpart. Homology modeling of above two mutants reflected a reduction of hydrogen bonds and an introduction of flexible residues in the loops near the active catalytic site Thr15. These changes contributed to the flexibility of loops, which may lead to further enhancement in catalytic efficiency. Results also showed that approximately 88.5% (0.978 mg/kg) acrylamide could be removed from mutant DD-12G pre-treated fried potato chips. This study clearly shows that directional evolution methods can indeed be utilized to improve the activity of l -asparaginase, which could also provide research basis for future application in food industry.

The relative vibration between the micro-milling cutter and workpiece influences the processing quality and tool life. To solve the difficult problem of measurement of vibration displacement between cutting tool and workpiece during micro-milling process, we designed a laser displacement sensor holder, which realizes the adjustment on multi degrees of freedom. A set of vibration displacement measurement system is developed, which utilizes laser displacement sensor to collect vibration signal during micro-milling process. The frequency of micro-milling force is obtained by using varying cutting parameters method. The relationship between cutting force amplitude, frequency and vibration displacement is ascertained by using neural network method to realize vibration displacement prediction under given cutting parameters. The research lays the foundation for vibration suppression of micro-milling, which can help improve surface quality and extend tool life.

The poor characteristics of Inconel 718, such as large plasticity, low thermal conductivity, and sensitivity to the strain rate, lead to serious problems in its micro-milling, particularly its work hardening, which lowers the fatigue and the corrosion resistance of micro parts and accelerate tool wear. Therefore, the studies pertaining to work hardening caused by micro-milling of Inconel 718 are needed. This paper studies the influence of cutting parameters, including the spindle speed, the feed rate per tooth, and the axial cutting depth, on surface Vickers hardness and predicts the Vickers hardness of the machined surface on Inconel 718. The authors adopt response surface methodology to build the Vickers hardness prediction model and rank the parameters based on their influences on surface Vickers hardness of micro-milled Inconel 718. According to our analyses, the spindle speed has the most influence on Vickers hardness, the axial cutting depth has an intermediate influence, and the feed rate per tooth has the least influence. A significant interactive influence between the spindle speed and the feed rate per tooth exists. The study could support the appropriate selection of cutting parameters in improving the characteristics of surface work hardening thereby the quality of the final product.

There has been a great increase in the applications of micro thin-walled parts in many fields, such as medical devices, aerospace and so on. The requirement of machining dimensional accuracy for micro thin-walled parts is very high. Inconel 718has the advantages of high strength and corrosion resistance, which can meet the requirements of micro thin-walled parts under poor applying working conditions. However, it is difficult to machine. Micro-milling is a potentially effective processing technique for processing Inconel 718 thin-walled parts. Because of the low rigidity, deflection of Inconel 718 thin-walled parts is easy to occur in micro-milling process, which affects the machining accuracy. So far, the research on the deflection of micro-milling Inconel 718 thin-walled parts is still blank. In this paper, a method of deflection prediction of micro-milling thin-walled parts is proposed. Firstly, a simulation model of micro-milling Inconel 718 thin-walled parts process is established, which realizes the prediction of milling force. Then, by using element birth/death technique, a deflection prediction model of micro-milling thin-walled parts is built based on the predicted value of milling force output by the simulation model, which achieves the more efficient and accurate deflection prediction of micro-milling thin-walled parts. Finally, the correctness of the built simulation model of micro-milling thin-walled parts process as well as the deflection prediction model of micro-milling thin-walled parts are verified by experiments. The research provides a feasible way for deflection prediction of micro-milling thin-walled parts, and lays foundation for deflection suppression and machining accuracy improvement of micro-milling thin-walled parts to a certain extent.

OBJECTIVE Patients with systemic lupus erythematosus (SLE) have increased mortality related to cardiovascular disease (CVD). This systematic review and meta-analysis identified the risk of CVD in SLE patients, CVD risk factors in SLE patients, and the risk of CVD in lupus nephritis (LN) patients. METHODS On-line databases were used to search the eligible studies from January 2013 to August 2020. The relevant characteristics and the data of disease extracted from included publications. RESULTS A total of 20 studies were included in this meta-analysis. Compared with the general or healthy population, the risk of CVD in SLE patients increased by 2 times (RR = 2.35, 95% CI: 1.95-2.84, P

Milling technique was proposed to fabricate close-loop hydrophilic groove (CLHG) patterns on superhydrophobic Al alloy surface. On account of the pinning force that derives from the milled smooth grooves, water can be trapped and stretched into thin water films with different shapes on the superhydrophobic substrate. The contact angle of 13 μL water film trapped by a circular CLHG with an outer diameter of 10.3 mm was only 5.8°. Water films trapped by the CLHGs are similar to those hydrophilic/superhydrophilic patterns and have great water trapping capacity. The critical water trapping volume (CWTV) and sliding resistance of droplets on the circular CLHGs versus outer diameters and groove widths of the CLHGs were investigated. The results indicate that both the CWTV and sliding resistance are independent of the groove widths but closely related to the CLHG outer diameters. Compared with plasma-treated superhydrophilic dots, the circular CLHGs have equal CWTV and sliding resistance. This water-film patterning method has advantages like high efficiency and less liquid loss in liquid shifting processes, and therefore can possibly find such applications as large-area liquid patterning and water storage on superhydrophobic substrates.

This paper presents a transit network optimization method, in which travel time reliability on road is considered. A robust optimization model, taking into account the stochastic travel time, is formulated to satisfy the demand of passengers and provide reliable transit service. The optimization model aims to maximize the efficiency of passenger trips in the optimized transit network. Tabu search algorithm is defined and implemented to solve the problem. Then, transit network optimization method proposed in this paper is tested with two numerical examples: a simple route and a medium-size network. The results show the proposed method can effectively improve the reliability of a transit network and reduce the travel time of passengers in general.

The interaction between 5-sulfosalicylic acid (SSA) and bovine serum albumin (BSA) at pH 7.40 was studied by fluorescence and UV–vis absorption spectroscopy at different temperatures. The results revealed that SSA caused the fluorescence quenching of BSA through a static quenching procedure. The binding constant K was measured by fluorescence quenching method. The thermodynamic parameters, ΔH and ΔS, were calculated to be 23.16 kJ mol−1>0 and 162.37 J mol−1 K−1>0, respectively, which suggested that the hydrophobic force played a major role in the reaction of SSA on BSA. The distance r between donor (BSA) and acceptor (SSA) was obtained according to the Forster non-radiation energy transfer theory. The results of synchronous fluorescence spectra, three-dimensional fluorescence spectra and far-UV circular dichroism spectra showed that the interaction between BSA and SSA induced conformational changes in BSA.

Structure-activity relationships for the MDM2-p53 inhibitory activity of a series of A-ring substituted 2-N-benzyl-3-(4-chlorophenyl)-3-(1-(hydroxymethyl)cyclopropyl)methoxy)isoindolinones have been investigated, giving rise to compounds with improved potency over their unsubstituted counterparts. Isoindolinone A-ring substitution with a 4-chloro group for the 4-nitrobenzyl, 4-bromobenzyl and 4-cyanobenzyl derivatives (10a-c) and substitution with a 6-tert-butyl group for the 4-nitrobenzyl derivative (10j) were found to confer additional potency. Resolution of the enantiomers of 10a showed that potent MDM2-p53 activity resided in the (-)-enantiomer ((-)-10a; IC(50)=44 ± 6 nM). The cellular activity of key compounds has been examined in cell lines with defined p53 and MDM2 status. Compounds 10a and (-)-10a increase p53 protein levels, activate p53-dependent MDM2 and p21 transcription in MDM2 amplified cells, and show improved selectivity for growth inhibition in wild type p53 cell lines over the parent compound.