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Effects of Tetracyclines on Primary Root Length and Chlorophyll Contents of Vegetable Crops
Hyeonji Choe,Hadjer Chohra,Vimalraj Kantharaj,Mi Sun Cheong,Yong Bok Lee 한국토양비료학회 2021 한국토양비료학회지 Vol.54 No.1
By increasing the use of antibiotics, it is concerned that unexpectedly contaminated the effect of antibiotics occurs in agricultural soil. In this study, we investigated the impact of antibiotics on the early stages of crop growth using lettuce (Lactuca sativa), cabbage (Brassica campestris), and radish (Raphanus raphanistrum). These crops were grown on agar plates vertically without antibiotics (0 ㎎/L) and with tetracycline 5 (TC5), 10 (TC10), and 20 (TC20) ㎎/L, chlortetracycline 5 (CTC5), 10 (CTC10), and 20 (CTC20) ㎎/L, and oxytetracycline 5 (OTC5), 10 (OTC10), and 20 (OTC20) ㎎/L at 20℃ for five days. Root length of all crops inhibited in a concentration-dependent manner except for cabbage of OTC treatment. For lettuce, root length (㎝) showed an average 6.06 and 1.39 upon control (0 ㎎/L) and TC20, respectively. Similarly, cabbage and radish exhibited an average 7.20 and 5.47, respectively, without TCs whereas TC20 inhibits the root length down to 2.26 and 1.59, respectively. The chlorophyll contents of cabbage and radish reduced as increased antibiotic concentration. Interestingly, chlorophyll contents of lettuce did not show significantly different. Therefore, we suggest future research directions by showing the effect of antibiotics on crops.
Blue-light emitting electrochemical cells comprising pyrene-imidazole derivatives
Lee, Hyeonji,Sunesh, Chozhidakath Damodharan,Subeesh, Madayanad Suresh,Choe, Youngson Elsevier 2018 Optical materials Vol.78 No.-
<P><B>Abstract</B></P> <P>Light-emitting electrochemical cells (LECs), the next-generation lighting sources are the potential replacements for organic light-emitting diodes (OLEDs). In recent years, organic small molecules (SMs) have established the applicability in solid-state lighting, and considered as prospective active materials for LECs with higher device performance. Here, we describe the synthesis of pyrene-imidazole based SMs, <B>PYR1,</B> and <B>PYR2</B> that differ by one pyrene unit and their characterization by various spectroscopic methods. To investigate the thermal, photophysical, and electrochemical properties of the two synthesized compounds, we performed thermogravimetric, UV–visible, photoluminescence (PL), and voltammetric measurements. The photoluminescence (PL) emission spectra of <B>PYR1</B> and <B>PYR2</B> measured in the acetonitrile solution, where <B>PYR1</B> and <B>PYR2</B> emit in the blue spectral region with peaks aligned at 383 nm and 389 nm, respectively. The fabricated LEC devices exhibited broader electroluminescence (EL) spectra with a significant red shift of the emission maxima to 446 nm and 487 nm, with CIE coordinates of (0.17, 0.18) and (0.18, 0.25) for <B>PYR1</B> and <B>PYR2</B>, respectively. The LECs based on <B>PYR1</B> and <B>PYR2</B> produced maximum brightness values of 180 and 72 cd m<SUP>−2</SUP> and current densities of 55 and 27 mA cm<SUP>−2</SUP>, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Pyrene-imidazole based SMs, <B>PYR1</B> and <B>PYR2</B> were synthesized and characterized. </LI> <LI> PL emission spectra of <B>PYR1</B> and <B>PYR2</B> emit in the blue spectral region. </LI> <LI> LECs exhibited broader EL spectra with a significant red shift than PL spectra. </LI> <LI> The LECs based on <B>PYR1</B> produced maximum brightness than <B>PYR2.</B> </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Young-Eun Yoon,Gang Sik Lee,Hyeonji Choe,Mi Sun Cheong,Shin Won Kang,Yong Bok Lee 한국토양비료학회 2021 한국토양비료학회지 Vol.54 No.1
In elevated hydroponic system, the physical and chemical characteristics of growing media used affects the quality of strawberries, which requires research on the reusability of growing media is needed for stable income of farmers. Therefore, in this study, the nutrient retention capacity of the growing media was indirectly confirmed by analyzing the content of minerals in the supply and drain of the nutrient solution used in elevated hydroponic system, and the possibility of long-term use of the growing media was investigated by comparing and analyzing the concentration of minerals according to the number of years of use. Strawberries used in this experiment were officially established as ‘Solhyang’ on September 1, 2018, and the supply and drainage water of the 1st, 2nd, and 3rd year cultivation system were collected 11 times at intervals of 2 weeks, depending on the number of years of use of the growing media. It was used for the analysis of the content of minerals, and the difference in the content of minerals in the supply and drainage was calculated as Δ value. As the year of use of the growing media increased, the pH and EC values decreased, and the pH decreased to the level of 3.9 - 4.9 in the third-year growing media. In addition, the Δ value of phosphorous of macro essential elements showed a tendency to decrease in the third-year growing media, whereas the Δ value of calcium showed a tendency to decrease as the years of use increased. In the case of boron, iron, and zinc, which are included in micro essential elements, Δ value tends to decrease as the number of years of use of the growing media increases.