Morphological development and photosynthetic acclimation of Panax ginseng seedlings to irradiation by light-emitting diodes (LEDs)

To determine the optimal light intensity and enable plants to cope with various environmental stresses in plant factories, the morphological and photosynthetic characteristics of ginseng seedlings, including the secondary metabolites, were investigated under six light intensities: 25, 50, 75, 100, 125, and 150 mu mol m(-2) s(-1). The shoot length increased with lower light intensity up to 75 mu mol m(-2) s(-1), and the leaf area and specific leaf weight were greatest at 100 and 75 mu mol m(-2) s(-1), respectively. Stomata frequency was higher from 100 mu mol m(-2) s(-1) with higher light intensity, and single stomatal pore length also increased at 150 mu mol m(-2) s(-1). Net photosynthetic rate at light saturation and net photosynthetic rate in growth condition increased sequentially up to 100 mu mol m(-2) s(-1) before rapidly decreasing at 150 mu mol m(-2) s(-1). The dark respiration rate and light compensation point were significantly high at 150 mu mol m(-2) s(-1) only. Fv/Fm and chlorophyll content statistically differed from 63 and 84 days after seedling stand, respectively. Thus, the leaves withered to death with higher light intensity. The ginsenoside content in the roots significantly increased according to the light intensity, and the panaxadiol/panaxatriol (PT) ratio tended to decrease as the PT-type ginsenosides increased further. Taken together, the range of 75-100 mu mol m(-2) s(-1) was found to be beneficial for growth, photosynthetic acclimation response, and total accumulated ginsenosides of ginseng seedlings.N

Physiological responses and ginsenoside production ofPanaxginseng seedlings grown under various ratios of red to blue light-emitting diodes

Ginseng, a semi-shade perennial plant, is greatly affected by light. However, light quality has only been studied in a few papers involving growth tests under monochromatic light or based on hairy root cultures. A plant factory with light-emitting diodes (LEDs) may provide high precision and standardization of ginseng seedlings for transplanting, and plant responses to light quality should be investigated for designing the optimal lighting conditions for this environment. In this study, various ratios of red light (R):blue light (B) were set from 100:0 to 0:100% at the same photosynthetic photon flux density of 75 mu mol m(-2) s(-1). As R increased, the shoot length became longer from R75B25, resulting in the single treatment of R being 1.68 times that of B. Compared to monochromatic R or B treatments, the overall growth of ginseng seedlings in R50B50 treatment increased. In the mesophyll structure, mixed light as R50B50 or while LEDs increased starch grains, and only R treatment led to dense chloroplasts in palisade and spongy parenchyma cells. Increasing R ratios had negative effects on CO(2)assimilation rate (A(N)), light-saturated net photosynthesis rate (A(sat)), and chlorophyll parameters. The higher the R ratio, the higher the ginsenoside content in leaves, while roots were less affected by spectral changes. Monochromatic R induced malformation and senescence of ginseng leaves, while the addition of 25% B was sufficient to prevent the abnormal development of leaves and dysfunctional photosynthetic operation of ginseng seedlings. The results suggest that combinations of R and B should be considered when designing artificial lighting systems for a closed-type plant factory since R affects the morphological characteristics and ginsenoside content of ginseng seedlings.N

Highly promising lithium difluorophosphate additive for excellent cycling performance of graphite anodes at high rates

Recently, lithium-ion batteries (LIBs) have gained recognition as reliable power sources for transportation applications. However, LIBs suffer from inferior rate capability, high cost, and safety issues. To achieve good performance in terms of power, the electrodes should allow rapid charge transport at the electrode-electrolyte interface and good electronic conduction at the electrode-current collector interface. Solid electrolyte interphase (SEI) between bulk electrolyte and the graphite anode surface is a crucial parameter which determines the performance of LiBs at high rate. The formation of protective films on the anodes through the use of reducible additives such as vinylene carbonate (VC) can lead to a noticeable improvement in the electrochemical properties of the anodes. Here, we present, for the first time, the highly promising lithium difluorophosphate (LiDFP) additive for the formation of more ionic conductive surface film on the graphite anode. LiDFP additive is successfully employed to overcome the poor rate capability and cycling instability of graphite anodes, which have the VC-derived surface. The combination of a novel additive, LiDFP, and VC contributed to the formation of a more ionically conductive and stable SEI layer, allowing faster kinetics of the graphite anodes and profoundly reducing electrolyte decomposition at the anode during cycling

A combination of lithium difluorophosphate and vinylene carbonate as reducible additives to improve cycling performance of graphite electrodes at high rates

Lithium difluorophosphate (LiDFP) as a reducible additive is employed to overcome the unsatisfactory rate capability and cycling instability of highly pressed graphite electrodes with high mass loading (8.1 mg/cm2) with a vinylene carbonate (VC)-derived surface film that hampers the charge transport at the graphite-electrolyte interface at high rates. Our investigation reveals that LiDFP modifies the surface chemistry induced by VC and makes a more ionically conductive surface film on graphite, ensuring good rate capability.close0