A Joint Control Strategy for Automobile Active Grille Shutter and Cooling Fan

Liu Chuanbo,Wang Zhengju,Fan Chaojie,Zhang Ruonan,Man Xingjia 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.6

As an emerging technology improving fuel consumption, active grille shutter (AGS) has been applied in engine cooling system. For the reason of unreasonable matching method of grille opening and cooling fan, the problem of engine overcooling is widespread. As components with similar function of adjusting cooling air flow, the AGS and the cooling fan are separated from each other in parameter matching and operation which reduce cooling efficiency and fuel economy. To achieve precise cooling and improve fuel economy, a joint control strategy for AGS and cooling fan was proposed by using computational fluid dynamics. In order to verify the feasibility of the strategy, the fuel economy tests were carried out at 0 km/h, 90 km/h and 120 km/h, respectively. The results showed that the fuel consumption under the three working conditions was reduced by 0.01 L/ 100 km, 0.07 L/ 100 km and 0.13 L/ 100 km, respectively, indicating that the proposed strategy can significantly reduce fuel consumption.

Effects of exogenous putrescine on the ultrastructure of and calcium ion flow rate in lettuce leaf epidermal cells under drought stress

Xu Zhu,Lin Wang,Yingyan Han,Chaojie Liu,Shuangxi Fan 한국원예학회 2019 Horticulture, Environment, and Biotechnology Vol.60 No.4

The alleviation eff ects of exogenous putrescine treatment on the ultrastructure of and calcium ion fl ow rate in lettuce ( Lactucasativa L.) leaf cells under drought stress were studied. Lettuce seedlings were treated with foliar sprays of 0.1 mM putrescinefor 8 days, after which drought stress was simulated by using 10% polyethylene glycol 6000. The morphological characteristicsof the seedlings and the calcium ion fl ow rate across stomatal guard cells were subsequently determined, and the leaf cellultrastructure was observed via transmission electron microscopy. Under drought stress, the morphological characteristics of the seedlings decreased, and calcium ion infl ux was predominant in the guard cells. In addition, compared to that under control conditions, the stomatal density under drought stress conditions increased signifi cantly, the open/closed stoma ratio was lower, and the degree of stomatal opening was smaller. Exogenous putrescine sprays eff ectively reduced the stomatal density, increased the degree of stomatal opening, and increased the proportion of open stomata. In addition, the chloroplasts became round in shape, the thylakoid structure became blurry in appearance, the number of starch grains decreased, many osmium granules were produced, and plasmolysis occurred in the mesophyll cells. However, the chloroplasts were elongated, the thylakoid structure was clear, the starch grains were abundant, few osmium granules were produced, and plasmolysis did not occur. The above results show that, by altering the leaf cell ultrastructure as well as the fl ow rate and direction of calcium ions in guard cells, exogenous putrescine eff ectively improves the drought tolerance of lettuce.

Effects of diff erent NO 3 − :NH 4 + ratios on the photosynthesis and ultrastructure of lettuce seedlings

Xu Zhu,Rui Yang,Yingyan Han,Jinghong Hao,Chaojie Liu,Shuangxi Fan 한국원예학회 2020 Horticulture, Environment, and Biotechnology Vol.61 No.3

Nitrate nitrogen (NO 3− ) and ammonium N (NH 4+ ) are the two main forms of nitrogen (N). The eff ects of the NO 3− :NH 4+ ratio(0:100, 25:75, 50:50, 75:25, and 100:0) in the nutrient solution on growth, pigment content, photosynthetic parameters, chlorophyll(Chl) precursor content, and chloroplast mitochondrial ultrastructure of lettuce leaves were evaluated to determine theappropriate N ratio for the growth of lettuce. The results showed that a ratio of nitrate to ammonium of 75:25 compared withthe single N form resulted in signifi cantly higher fresh weights in the shoots and the lower parts of the lettuce. The growthrate, as indicated by the CO 2 response curve, was increased because of the carboxylation effi ciency and dark respiration rate(Rday) of the lettuce seedlings, and the diff erence between the light compensation point and CO 2 compensation point wasreduced under single nitrate N treatment. The contents of δ-aminolevulinic acid (ALA), porphobilinogen, uroporphyrinogenIII, protoporphyrin IX, and Mg-protoporphyrin IX in seedlings at 75:25 nitrate:ammonium were higher than those inseedlings under the other treatments. The contents of Chl a and b were also the highest when the ratio of nitrate ammoniumwas 75:25. The chloroplast structure of lettuce leaves was intact, the cell membrane was completely closed to the cell wall,and the organelles were closely arranged on the cell membrane. The chloroplast was spindle-shaped and full of vesicles. The whole mitochondria were rich, the base particles were rich, the base granules were clear and rich, and the mitochondriaexhibited the overall best state with a complete structure, rich sputum, and dense inclusions. The above results show that thenutrient solution with a ratio of nitrate to ammonium of 75:25 was more conducive to Chl synthesis and the promotion ofphotosynthesis and root growth in lettuce seedlings than the other treatments. The single nitrate N nutrient solution reducedChl synthesis and photosynthesis in lettuce seedlings, while the single ammonium N nutrient solution aff ected the growthof lettuce seedlings, resulting in lower growth of lettuce shoots and roots. Therefore, the nutrient solution ratio of nitrate toammonium of 75:25 is the most suitable for the lettuce seedling growth.

MiR-1165-3p Suppresses Th2 Differentiation via Targeting IL-13 and PPM1A in a Mouse Model of Allergic Airway Inflammation

Zhengxia Wang,Ningfei Ji,Zhongqi Chen,Zhixiao Sun,Chaojie Wu,Wenqing Yu,Fan Hu,Mao Huang,Mingshun Zhang 대한천식알레르기학회 2020 Allergy, Asthma & Immunology Research Vol.12 No.5

Purpose: CD4+T cells are essential in the pathogenesis of allergic asthma. We have previously demonstrated that microRNA-1165-3p (miR-1165-3p) was significantly reduced in T-helper type (Th) 2 cells and that miR-1165-3p was a surrogate marker for atopic asthma. Little is known about the mechanisms of miR-1165-3p in the regulation of Th2-dominated allergic inflammation. We aimed to investigate the associations between Th2 differentiation and miR-1165b-3p in asthma as well as the possible mechanisms. Methods: CD4+ naïve T cells were differentiated into Th1 or Th2 cells in vitro. MiR-1165-3p was up-regulated or down-regulated using lentiviral systems during Th1/Th2 differentiation. In vivo, the lentiviral particles with the miR-1165-3p enhancer were administered by tail vein injection on the first day of a house dust mite -induced allergic airway inflammation model. Allergic inflammation and Th1/Th2 differentiation were routinely monitored. To investigate the potential targets of miR-1165-3p, biotin-microRNA pull-down products were sequenced, and the candidates were further verified with a dual-luciferase reporter assay. The roles of a target protein phosphatase, Mg2+/Mn2+-dependent 1A (PPM1A), in Th2 cell differentiation and allergic asthma were further explored. Plasma PPM1A was determined by ELISA in 18 subjects with asthma and 20 controls. Results: The lentivirus encoding miR-1165-3p suppressed Th2-cell differentiation in vitro. In contrast, miR-1165-3p silencing promoted Th2-cell development. In the HDM-induced model of allergic airway inflammation, miR-1165-3p up-regulation was accompanied by reduced airway hyper-responsiveness, serum immunoglobulin E, airway inflammation and Th2-cell polarization. IL-13 and PPM1A were the direct targets of miR-1165-3p. The expression of IL-13 or PPM1A was inversely correlated with that of miR-1165-3p. PPM1A regulated the signal transducer and activator of transcription and AKT signaling pathways during Th2 differentiation. Moreover, plasma PPM1A was significantly increased in asthmatic patients. Conclusions: MiR-1165-3p negatively may regulate Th2-cell differentiation by targeting IL-13 and PPM1A in allergic airway inflammation.

The establishment of a DNA fifi ngerprinting database for 73 varieties of Lactuca sativa capitate L. using SSR molecular markers

Huiyan Zhou,Penghang Zhang,Jiang Luo,Xueying Liu,Shuangxi Fan,Chaojie Liu,Yingyan Han 한국원예학회 2019 Horticulture, Environment, and Biotechnology Vol.60 No.1

Head lettuce originating near the Mediterranean coast was introduced to China in the fi fth century. It is diffi cult to identifydiff erent varieties of head lettuce due to their close genetic relationships. Simple sequence repeats (SSR) technology is apractical method that has been widely used in variety identifi cation, fi ngerprint construction and genetic diversity analysis. In this paper, 23 pairs of SSR primers were selected to identify and analyse 73 varieties of head lettuce. The results identified a total of 117 mutated alleles detected in 23 loci, with the number of each loci ranging from 2 to 11, with an averageof 5.1 mutated alleles per locus. Additionally, 152 genotypes were detected in 23 loci, with an average of 6.6 genotypes perlocus derived from a range of 2–13. The polymorphism information content ranged from 0.071 to 0.702, with an average of0.499. The selected primer pairs could clearly refl ect the genotypic diversity level of the 73 head lettuce varieties tested, andcan be used in the detection and analysis of the head lettuce varieties. The results of our sequence analysis also showed thatthese 73 varieties of head lettuce could be eff ectively identifi ed by a combination of 19 primer pairs even though the geneticsimilarity among the 73 varieties ranged from 0.647 to 0.991, with an average of 0.798. Based on a capillary electrophoresisplatform, a DNA fi ngerprinting database of 73 head lettuce varieties was established.