• 생물환경조절학회지
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• 제31권4호
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• pp.460-467
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• 2022

본 연구에서는 양액재배 시 발생되는 폐양액의 적절한 농업적 이용방안을 강구하기 위해 폐양액의 비료 효과시험, 토양컬럼 시험, 그리고 작물 재배시험을 수행하였다. 폐양액의 비료 효과시험은 무기질소를 기준으로 질소비료와 폐양액의 토양 처리에 따른 열무의 생육특성과 토양의 화학적 특성을 조사하였다. 폐양액 비료 효과시험과 작물 재배시험을 위한 토양에 대한 폐양액의 처리는 무처리; A, 질소비료 100%; B, 질소비료 70%+폐양액 30%; C, 질소비료 50%+폐양액 50%; D, 질소비료 30%+폐양액 70%; E 총 5개 처리구로 하였다. 토양컬럼 시험을 위한 토양에 대한 폐양액의 처리는 무처리, 질소비료 100%, 폐양액 50%+질소비료 50% 3개 처리구로 하였다. 폐양액의 화학성은 pH 6.0, EC 2.4dS·m^-1, 총인(T-P) 28mg·L^-1, 암모늄태 질소(NH₄-N) 5.0mg·L^-1, 질산태 질소(NO₃-N) 301mg·L^-1로 나타났다. 토양의 화학성은 pH 5.51, EC 0.31dS·m^-1, 유기물 2.08g·kg^-1, 질산태 질소 9.64mg·kg^-1, 암모늄태 질소 3.20mg·kg^-1으로 나타났다. 질소비료 50% 이하와 폐양액 50% 이상의 비율이 열무 생육에 효과가 높은 것으로 나타났다. 폐양액을 질소비료와 함께 혼합하여 적용한 C-E 처리구에서 토양의 이화학성은 질소비료만을 적용한 B 처리구와 통계적으로 유의한 차이가 없었다. 토양컬럼 시험 결과 질소비료 100%와 폐양액 50%+질산비료 50% 처리구의 NO₃와 NH₄의 농도는 큰차이가 없는 것으로 나타났다. 폐양액을 화학비료의 표준시비량을 기준으로 이용하여 토양에 처리하면 토양 내 질소 성분의 이동과 주변의 영향은 일반 화학비료와 유사하게 나타나는 것으로 판단된다. 열무 토경재배에 폐양액과 질소비료를 혼합하여 사용하면 폐양액의 재이용으로 환경적 부담도 줄일 수 있고, 질소비료의 사용량도 줄일 수 있어 농가에 경제적 부담 감소와 열무 생산량 증대 효과도 기대할 수 있다.

• ALGAE
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• 제31권3호
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• pp.257-266
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• 2016

Nitrogen is one of the most critical nutrients affecting cell growth and biochemical composition of microalgae, ultimately determining the lipid or carbohydrate productivity for biofuels. In order to investigate the effect of nitrogen sources on the cell growth and biochemical composition of the marine microalga Tetraselmis sp., nine different N sources, including NaNO₃, KNO₃, NH₄NO₃, NH₄HCO₃, NH₄Cl, CH₃COONH₄, urea, glycine, and yeast extract were compared at the given concentration of 8.82 mM. Higher biomass concentration was achieved under organic nitrogen sources, such as yeast extract (2.23 g L⁻¹) and glycine (1.62 g L⁻¹), compared to nitrate- (1.45 g L⁻¹) or ammonium-N (0.98 g L⁻¹). All ammonium sources showed an inhibition of cell growth, but accumulated higher lipids, showing a maximum content of 28.3% in ammonium bicarbonate. When Tetraselmis sp. was cultivated using yeast extract, the highest lipid productivity of 36.0 mg L⁻¹ d⁻¹ was achieved, followed by glycine 21.5 mg L⁻¹ d⁻¹ and nitrate 19.9 mg L⁻¹ d⁻¹. Ammonium bicarbonate resulted in the lowest lipid productivity of 14.4 mg L⁻¹ d⁻¹. The major fatty acids in Tetraselmis sp. were palmitic, oleic, linoleic and linolenic acids, regardless of the nutritional compositions, indicating the suitability of this species for biodiesel production.

• The Korean Journal of Physiology and Pharmacology
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• 제26권6호
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• pp.531-540
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• 2022

Group 1 metabotropic glutamate receptors (mGluRs) can positively affect postsynaptic neuronal excitability and epileptogenesis. The objective of the present study was to determine whether group 1 mGluRs might be involved in synaptically-induced intracellular free Ca²⁺ concentration ([Ca²⁺]_i) spikes and neuronal cell death induced by 0.1 mM Mg²⁺ and 10 µM glycine in cultured rat hippocampal neurons from embryonic day 17 fetal Sprague-Dawley rats using imaging methods for Ca²⁺ and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays for cell survival. Reduction of extracellular Mg²⁺ concentration ([Mg²⁺]_o) to 0.1 mM induced repetitive [Ca²⁺]_i spikes within 30 sec at day 11.5. The mGluR5 antagonist 6-Methyl2-(phenylethynyl) pyridine (MPEP) almost completely inhibited the [Ca²⁺]_i spikes, but the mGluR1 antagonist LY367385 did not. The group 1 mGluRs agonist, 3,5-dihydroxyphenylglycine (DHPG), significantly increased the [Ca²⁺]_i spikes. The phospholipase C inhibitor U73122 significantly inhibited the [Ca²⁺]_i spikes in the absence or presence of DHPG. The IP₃ receptor antagonist 2-aminoethoxydiphenyl borate or the ryanodine receptor antagonist 8-(diethylamino)octyl 3,4,5-trimethoxybenzoate also significantly inhibited the [Ca²⁺]_i spikes in the absence or presence of DHPG. The TRPC channel inhibitors SKF96365 and flufenamic acid significantly inhibited the [Ca²⁺]_i spikes in the absence or presence of DHPG. The mGluR5 antagonist MPEP significantly increased the neuronal cell survival, but mGluR1 antagonist LY367385 did not. These results suggest a possibility that mGluR5 is involved in synaptically-induced [Ca²⁺]_i spikes and neuronal cell death in cultured rat hippocampal neurons by releasing Ca²⁺ from IP₃ and ryanodine-sensitive intracellular stores and activating TRPC channels.

• Nuclear Engineering and Technology
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• 제52권6호
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• pp.1201-1207
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• 2020

This study explored whether MXene (Ti₃C₂T_x) could remove radioactive Cs⁺ from model nuclear wastewater. Various adsorption tests were performed and the physical aspects of the interaction were investigated. We varied the MXene dosage, Cs⁺ initial concentration, solution pH, solution temperature and exposure time. MXene adsorption exhibited very fast kinetics, based on the fact that equilibrium was achieved within 1 h. MXene exhibited an outstanding adsorption capacity (148 mg g^-1) at adsorbent and adsorbate concentrations of 5 and 2 mg L^-1, respectively, at neutral pH condition (i.e., pH 7). We explored Cs⁺ adsorption by MXene in the presence of four different ions (NaCl, KCl, CaCl₂ and MgCl₂) and three different organic acids (sodium oleate, oxalic acid, and citric acid). The Cs⁺ removal rate changed in the presence of these components; adsorption of Cs⁺ by MXene thus involved ion exchange, supported by both Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. We confirmed that MXene was re-usable for at least four cycles. MXene is cost-effective and practical when used to adsorb radionuclides (e.g., Cs⁺) in nuclear wastewater.

• 한국응용과학기술학회지
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• 제36권4호
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• pp.1096-1107
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• 2019

녹두의 기능성 식품 소재로서 활용 가능성을 알아보고자 이화학적 특성에 관하여 분석한 결과, 일반성분 중 탄수화물 함량은 57.20±0.29%로 절반을 차지하였으며, 조단백질 26.40±0.69%, 수분 9.90±0.16%, 조회분 3.54±0.43% 및 조지방 2.96±0.26%로 확인되었다. 녹두의 비타민 성분 중 vitamin B₅가 0.62±0.013 mg/100 g으로 높은 함량을 나타내었으며, 비타민 A의 전구체인 β-carotene이 87.37±0.754 ㎍ RE/100 g으로 동정되었다. 칼륨(K) 함량은 12,428.55±147.55 mg kg^-1로 가장 높게 나타났고, 마그네슘(Mg)은 2,053.32±14.13 mg kg^-1, 칼슘(Ca) 1,966.40±14.53 mg kg^-1을 함유하고 있었으며, 녹두의 총 지방산 중 포화지방산은 29.23±0.03%의 함유량을 보였으며, 단불포화지방산은 20.30±0.04%, 다불포화지방산은 50.46±0.06%의 비율로 불포화지방산 함유량이 높은 것으로 나타났다. 특히, ω-6계 linoleic acid가 41.19±0.02%, ω-9계 oleic acid 19.98±0.03%를 함유하고 있었다. 총 아미노산 함량은 21.75±0.24 g%이며, glutamic acid 3.93±0.03 g%, aspartic acid 2.68±0.03 g% 등을 함유하고 있었고, glutamic acid 및 aspartic acid가 총 아미노산 함유량의 18.07%, 12.32%를 차지하였으며, 구성 아미노산의 대부분을 차지하는 것으로 나타났다. 녹두 중, 총 유리 아미노산 함량은 336.77±8.66 mg%로 확인되었고, arginine이 81.97±1.31 mg%로 유리 아미노산의 24.34%를 차지하는 것으로 나타났다. glutamic acid, asparagine 및 aspartic acid 순으로 각각, 41.97±0.29, 28.47±0.15 및 26.97±0.12 mg% 함유된 것으로 분석되었다.

• 산업융합연구
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• 제19권4호
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• pp.65-74
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• 2021

본 연구는 단거리 달리기선수의 고강도 훈련 시 중탄산염 섭취가 혈액변인에 미치는 영향 규명하는데 연구의 목적이 있다. S시 남·여 단거리달리기 선수로 등록된 운동경력 3년 이상의 엘리트 선수 30명을 대상으로 통제집단, 훈련집단, 중탄산염 투여와 훈련집단의 세 집단으로 설정 후, 고강도 운동프로그램은 통제집단과 중탄산염 투여와 훈련집단을 대상으로 80-90%HRmax 운동강도를 2-3주마다 증가시키며, 총 8주간, 주 5일, 1회 90분 실시하였다. 중탄산염 섭취는 중탄산염 투여와 훈련집단을 대상으로 체중 1kg당 300mg을 고강도 운동프로그램 시작 90분 전 1일 1회 8주간 섭취하였다. 연구결과, 단거리달리기 선수의 고강도 훈련 시 중탄산염의 섭취가 혈액변인에 미치는 효과는 중탄산염 투여와 훈련집단에서 수소이온농도의 상승과 젖산의 감소에 긍정적인 효과가 나타났으며, Ca²⁺, Na⁺, K⁺은 훈련집단과 중탄산염 투여와 훈련집단에서 유의한 증가가 나타났다. Mg²⁺은 세 집단 모두에서 유의한 변화를 나타내지 않았다. 고강도 훈련 시 중탄산염의 섭취가 혈액변인의 변화 중 수소이온농도의 증가와 젖산의 감소에 효과적인 변화가 나타나는 것을 확인 할 수 있다. 따라서 고강도 운동 시 중탄산염의 섭취가 운동능력의 개선에 효과적임을 알 수 있다.

• 분석과학
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• 제36권1호
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• pp.1-11
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• 2023

A new, sensitive, and reliable flow injection methodology was investigated for the determination of lead ion (II) in vegetables' samples using a laboratory-prepared reagent 2-[(6-methoxy-2-benzothiazoly)azo]-4-methoxy phenol (6-MBTAMP). Infrared spectroscopy, UV-visible spectrophotometry, Energy dispersive X-ray spectroscopy (EDX), Elemental Analysis (CHN), nuclear magnetic resonance spectroscopy ¹HNMR, and ¹³CNMR techniques were used to characterize the reagent and lead (II) complex. The method is based on lead ion (II) reacting with the reagent (6-MBTAMP) in a neutral solution to produce a green-red complex with a maximum absorbance at 670 nm. The optimum conditions, such as flow rate, lead ion (II) volume, reagent volume, medium pH, reagent concentration, and reaction coil length were thoroughly examined. The limits of detection (LOD) and quantification (LOQ) were determined to be 0.621 mg·L^-1 and 2.069 mg·L^-1 , respectively, while Sandell's sensitivity was determined to be 0.345 ㎍·cm^-2.

• Journal of Ecology and Environment
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• 제44권2호
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• pp.72-80
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• 2020

Background: Antibiotics are widely used to treat animals from infections. After fertilizing, antibacterials can remain in the soil while adversely affecting the soil microorganisms. The concentration of oxytetracycline (OTC) in the soil and its effect on the soil microbial community was assessed. To assess the impact of OTC on the soil microbial community, it was added to the soil at concentrations of 50, 150, and 300 mg kg^-1 and incubated for 35 days. Results: The concentration of OTC added to the soil decreased from 150 to 7.6 mg kg^-1 during 30 days of incubation, as revealed by LC-MS. The deviations from the control values in the level of substrate-induced respiration on the 5th day of the experiment were, on average, 26, 68, and 90%, with OTC concentrations at 50, 150, and 300 mg kg^-1, respectively. In samples with 150 and 300 mg kg^-1 of OTC, the number of bacteria from the 3rd to 14th day was 2-3 orders of magnitude lower than in the control. The addition of OTC did not affect the fungal counts in samples except on the 7th and 14th days for the 150 and 300 mg kg^-1 contaminated samples. Genes tet(M) and tet(X) were found in samples containing 50, 150, and 300 mg kg^-1 OTC, with no significant differences in the number of copies of tet(M) and tet(X) genes from the OTC concentration. Conclusions: Our results showed that even after a decrease in antibiotic availability, its influence on the soil microbial community remains.

• Asian-Australasian Journal of Animal Sciences
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• 제33권1호
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• pp.127-131
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• 2020

Objective: This study was conducted to determine catalytic properties of wheat phytase with exopolyphosphatase activity toward medium-chain and long-chain inorganic polyphosphate (polyP) substrates for comparative purpose. Methods: Exopolyphosphatase assay of wheat phytase toward polyP75 (medium-chain polyP with average 75 phosphate residues) and polyP1150 (long-chain polyP with average 1150 phosphate residues) was performed at pH 5.2 and pH 7.5. Its activity toward these substrates was investigated in the presence of Mg²⁺, Ni²⁺, Co²⁺, Mn²⁺, or ethylenediaminetetraacetic acid (EDTA). Michaelis constant (K_m) and maximum reaction velocity (V_max) were determined from Lineweaver-Burk plot with polyP75 or polyP1150. Monophosphate esterase activity toward p-nitrophenyl phosphate (pNPP) was assayed in the presence of polyP75 or polyP1150. Results: Wheat phytase dephosphorylated polyP75 and polyP1150 at pH 7.5 more effectively than that at pH 5.2. Its exopolyphosphatase activity toward polyP75 at pH 5.2 was 1.4-fold higher than that toward polyP1150 whereas its activity toward polyP75 at pH 7.5 was 1.4-fold lower than that toward polyP1150. Regarding enzyme kinetics, K_m for polyP75 was 1.4-fold lower than that for polyP1150 while V_max for polyP1150 was 2-fold higher than that for polyP75. The presence of Mg²⁺, Ni²⁺, Co²⁺, Mn²⁺, or EDTA (1 or 5 mM) exhibited no inhibitory effect on its activity toward polyP75. Its activity toward polyP1150 was inhibited by 1 mM of Ni²⁺ or Co²⁺ and 5 mM of Ni²⁺, Co²⁺, or Mg²⁺. Ni²⁺ inhibited its activity toward polyP1150 the most strongly among tested additives. Both polyP75 and polyP1150 inhibited the monophosphate esterase activity of wheat phytase toward pNPP in a dose-dependent manner. Conclusion: Wheat phytase with an unexpected exopolyphosphatase activity has potential as a therapeutic tool and a next-generational feed additive for controlling long-chain polyP-induced inappropriate inflammation from Campylobacter jejuni and Salmonella typhimurium infection in public health and animal husbandry.

• 운동영양학회지
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• 제13권1호
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• pp.75-81
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• 2009

This study aims to find out the effect of ingestion of 3 mg·kg^-1 caffeine on fluid-electrolyte balance and Tty change during exercise under heat environment of 30~32℃ (40-50% humidity). Five trained males who routinely trained for approximately 60 min·d^-1, 3-6 d·wk^-1 (age; 28.20±3.56yrs, height; 174.56±5.46 cm, body mass; 76.13±9.02 kg, body fat(%); 14.24±3.99, VO₂max; 54.00±4.30 mL·kg^-1·min^-1, exercise career; 4.20±1.95yrs) performed 40min of treadmill running in heat chamber. The study was a double-blind, randomized, crossover design. Body mass change following exercise was higher for the PLAC (Placebo) and CAFF (Caffeine) in comparison to the CON (Control), there was no significant difference between the CAFF, PLAC, CON (p= .997). The U_sg not significant differences (p= .731) and Osm_urine not significant differences between the CAFF, PLAC, CON (p= .901). There also were not significant between the CAFF, PLAC, CON for [Na⁺]_urine and [K⁺]_urine (p= .928, p= .469). In the case of Tty, although the increase rate of Tty was the highest for the CAFF on exercise early, exercise the second half in comparison to the CON and PLAC, there was not significant interaction effect between the CAFF, PLAC, and CON of Tty (p= .067), In conclusion, it was confirmed that the 3 mg·kg^-1 caffeine ingestion prior to exercising in heat environment does not impart negative effect on body fluid, electrolyte balance and changes in Tty.