• The Korean Journal of Physiology and Pharmacology
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• 제25권6호
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• pp.525-532
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• 2021

We have investigated the relative roles of α₁-adrenoceptors and purinoceptors in contractions to low and high frequency stimulation of the mouse vas deferens, in terms of the time course of responses. In separate experiments, isometric contractile responses were obtained to 10 pulses at 1 Hz and 40 pulses at 10 Hz. Responses to 1 Hz stimulation consisted of a series of discrete peaks. The α_1A-adrenoceptor antagonist RS100329 (10^-9M-10^-7M) significantly reduced the response to the first pulse, the α_1D-adrenoceptor antagonist BMY7378 (10^-7M-10^-6M) significantly reduced the response to the first two pulses, and the non-selective α₁-adrenoceptor antagonist prazosin (10^-8M) reduced the response to the first 4 pulses at 1 Hz. Responses to 10 Hz stimulation consisted of an early peak response and a maintained plateau response. RS100329 significantly reduced the peak response but did not significantly affect the plateau response. Prazosin, significantly reduced both the peak and plateau responses. The α_1A-adrenoceptor antagonist RS17053 in high concentrations reduced mainly the plateau response leaving a clear early peak response. The plateau response of contraction was almost abolished by the purinoceptor antagonist suramin. These results suggest that there is a relatively minor early α_1D-adrenoceptor and a larger early α_1A-adrenoceptor component to stimulationevoked contractions of mouse vas deferens, but the major α₁-adrenoceptor component is revealed by prazosin to be α_1B-adrenoceptor mediated. α_1B-Adrenoceptor activation probably facilitates contractions mediated by other α₁-adrenoceptors and by purinoceptors. These results suggest that combined non-selective α₁-adrenoceptor blockade, particularly α_1B-adrenoceptor blockade, in addition to P2X1-purinoceptor blockade is useful in reducing male fertility.

• 한국해양바이오학회지
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• 제12권2호
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• pp.81-90
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• 2020

Sialic acid, which is contained in about 60-160 mg/kg in the edible bird's nest (EBN), is known to facilitate in the proper formation of synapses and improve memory function. The objective of this study is to extract effectively the sialic acid from edible bird's nest using affinity bead technology (ABT). After preparing the non-polar polymeric bead "KJM-278-28A" having a porous network structure, and then desorbed sialic acid was concentrated and dried. The analysis of the physicochemical properties of bead "KJM-278-28A" showed that the particle size was 400-700 ㎛, the moisture holding capacity was 67-70%, the surface area (BET) was 705-900 ㎡/g, and the average pore diameter 70-87 Å. The adsorption capacity of the bead "KJM-278-28A" for sialic acid was shown a strong physical force to bind sialic acid to the bead surface of 400 mg/L. In addition, as a result of analyzing the adsorption and desorption effects of sialic acid on water, ethanol, and 10% ethanol on the bead, it was confirmed that desorption effectively occurs from the beads when only ethanol is used. As a result of HPLC measurement of the separated sialic acid solution, a total of four sialic acid peaks of N-acetyl-neuraminic acid (Neu5Ac), α,β-anomer of Neu5Ac and N-glycoly-neuraminic acid were identified. Through these results, it was confirmed that it is possible to separate sialic acid from EBN extract with efficient and high yield when using ABT.

• 한국표면공학회지
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• 제34권5호
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• pp.414-420
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• 2001

A 30-kV plasma immersion ion implantation setup (P $I^3$) has been equipped with a self-developed 6'-magnetron to perform hard coatings with enhanced adhesion by P $I^3$D(P $I^3$ assisted deposition) process. Using ICP source with immersed Ti antenna and reactive magnetron sputtering of Ti target in $N_2$/Ar ambient gas mixture, the TiN films were prepared on Si substrates at different pulse bias and ion-to-atom arrival ratio ( $J_{i}$ $J_{Me}$ ). Prior to TiN film formation the nitrogen implantation was performed followed by deposition of Ti buffer layer under A $r^{+}$ irradiation. Films grown at $J_{i}$ $J_{Me}$ =0.003 and $V_{pulse}$=-20kV showed columnar grain morphology and (200) preferred orientation while those prepared at $J_{i}$ $J_{Me}$ =0.08 and $V_{pulse}$=-5 kV had dense and eqiaxed structure with (111) and (220) main peaks. X-ray diffraction patterns revealed some amount of $Ti_{x}$ $N_{y}$ in the films. The maximum microhardness of $H_{v}$ =35 GN/ $M^2$ was at the pulse bias of -5 kV. The P $I^3$D technique was applied to enhance wear properties of commercial tools of HSS (SKH51) and WC-Co alloy (P30). The specimens were 25-kV PII nitrogen implanted to the dose 4.10$^{17}$ c $m^{-2}$ and then coated with 4-$\mu\textrm{m}$ TiN film on $Ti_{x}$ $N_{y}$ buffer layer. Wear resistance was compared by measuring weight loss under sliding test (6-mm $Al_2$ $O_3$ counter ball, 500-gf applied load). After 30000 cycles at 500 rpm the untreated P30 specimen lost 3.10$^{-4}$ g, and HSS specimens lost 9.10$^{-4}$ g after 40000 cycles while quite zero losses were demonstrated by TiN coated specimens.s.

• 한국재료학회지
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• 제32권2호
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• pp.66-71
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• 2022

In this article, Pb₂Ba_1.7Sr_0.3Ca₂Cu₃O_10+δ superconductor material was synthesized using conventional solid-state reaction method. X-ray diffraction (XRD) analysis demonstrated one dominant phase 2223 and some impurities in the product powder. The strongest peaks in the XRD pattern were successfully indexed assuming a pseudo-tetragonal cell with lattice constants of a = 3.732, b = 3.733 and c = 14.75 Å for a Pb-Based compound. The crystallite size and lattice strain between the layers of the studied compound were estimated using several methods, namely the Scherrer, Williamson-Hall (W.H), size-strain plot (SSP) and Halder Wagner (H.W) approach. The values of crystallite size, calculated by Scherrer, W.H, SSP and H.W methods, were 89.4540774, 86.658638, 87.7555823 and 85.470086 Å, respectively. Moreover, the lattice strain values obtained by W.H, SSP and H.W methods were 0.0063240, 0.006325 and 0.006, respectively. It was noted that all crystallite size results are consistent; however, the best method is the size-strain plot because it gave a value of R² approaching one. Furthermore, degree of crystallites was calculated and found to be 59.003321%. Resistivity analysis suggests zero-resistance, which is typical of superconducting materials at critical temperature. Four-probe technique was utilized to measure the critical temperature at onset T_c(onset), zero resistivity T_{c(off set)}, and transition (width ΔT), corresponding to temperatures of 128 K, 116 K, and 12 K, respectively.

• 한국미생물·생명공학회지
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• 제51권2호
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• pp.157-166
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• 2023

Three lactic acid bacteria (LAB) producing exopolysaccharides (EPSs) were isolated from Pa (green onion)-kimchi, and identified as Weissella confusa (SKP 173), Weissella cibaria (SKP 182), and Leuconostoc citreum (SKP 281), respectively by 16S rRNA gene sequencing. The yields of EPS were 21.27, 18.53, and 15.4 g/l for EPS from SKP 173, 182, and 281, respectively when grown in MRS broth containing sucrose (5%, w/v). Total sugar contents were 64.39, 62.84, and 65.16% (w/w) for EPS from SKP 173, 182, and 281, respectively while the protein contents were 0.33, 0.31, and 0.25% (w/w), respectively. EPSs from W. confusa SKP 173 and W. cibaria SKP 182 contained glucose only but EPS from L. citreum SKP 281 contained glucose and glucitol. Viscosities of the 2% (w/w) freeze-dried EPS solution were 9.60, 8.00, and 8.20 centipoise (cP) for EPS from SKP 173, 182, and 281, respectively. Viscosities of culture grown in MRS broth with 5% sucrose (no glucose) were 92.98, 57.19, and 18.8 cP, respectively. The average molecular weights of EPSs were larger than 2 × 10⁷ Da. Fourier transform infrared spectroscopy (FT-IR) analyses of EPSs showed typical carbohydrate peaks, suggesting that the EPSs consisted of pyranose saccharides with α-(1,6) and α-(1,3) glycosidic linkages. L. citreim SKP 281 was used as the starter for yogurt fermentation, and EPS production was confirmed.

• Korean Journal of Radiology
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• 제20권1호
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• pp.126-133
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• 2019

Objective: To compare the lumbar vertebral bone marrow fat-signal fractions obtained from six-echo modified Dixon sequence (6-echo m-Dixon) with those from single-voxel magnetic resonance spectroscopy (MRS) in patients with low back pain. Materials and Methods: Vertebral bone marrow fat-signal fractions were quantified by 6-echo m-Dixon (repetition time [TR] = 7.2 ms, echo time (TE) = 1.21 ms, echo spacing = 1.1 ms, total imaging time = 50 seconds) and single-voxel MRS measurements in 25 targets (23 normal bone marrows, two focal lesions) from 24 patients. The point-resolved spectroscopy sequence was used for localized single-voxel MRS (TR = 3000 ms, TE = 35 ms, total scan time = 1 minute 42 seconds). A 2 × 2 × 1.5 cm³ voxel was placed within the normal L2 or L3 vertebral body, or other lesions including a compression fracture or metastasis. The bone marrow fat spectrum was characterized on the basis of the magnitude of measurable fat peaks and a priori knowledge of the chemical structure of triglycerides. The imaging-based fat-signal fraction results were then compared to the MRS-based results. Results: There was a strong correlation between m-Dixon and MRS-based fat-signal fractions (slope = 0.86, R² = 0.88, p < 0.001). In Bland-Altman analysis, 92.0% (23/25) of the data points were within the limits of agreement. Bland-Altman plots revealed a slight but systematic error in the m-Dixon based fat-signal fraction, which showed a prevailing overestimation of small fat-signal fractions (< 20%) and underestimation of high fat-signal fractions (> 20%). Conclusion: Given its excellent agreement with single-voxel-MRS, 6-echo m-Dixon can be used for visual and quantitative evaluation of vertebral bone marrow fat in daily practice.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4671-4677
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• 2023

For the first time Pb, Ni, and Cu nanocomposites were synthesized by versatile solution combustion synthesis using Aloevera extract as a reducing agent, to study the potential applications in X-ray/gamma, neutron, and Bremsstrahlung shielding. The synthesized Lead-Nickel-Copper (LNC) nanocomposites were characterized by PXRD, SEM, UV-VIS, and FTIR for the confirmation of successful synthesis. PXRD analysis confirmed the formation of multiphase LNC NCs and the Scherrer equation and the W-H plot gave the average crystal sizes of 19 nm and 17 nm. Surface morphology using SEM and EDX confirmed the presence of LNC NCs. Strong absorption peaks were analyzed by UV visible spectroscopy and the direct energy gap is found to be 3.083 eV. Functional groups present in the LNC NCs were analyzed by FTIR spectroscopy. X-ray/gamma radiation shielding properties were measured using NaI(Tl) detector coupled with MCA. It is found to be very close to Pb. Neutron shielding parameters were compared with traditional shielding materials and found LNC NCs are better than lead and concrete. Secondary radiation shielding known as Bremsstrahlung shielding characteristics also studied and found that LNC NCs are best in secondary radiation shielding. Hence LNC NCs find shielding applications in ionizing radiation such as X-ray/gamma and neutron radiation.

• 한국해양학회지
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• 제24권3호
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• pp.157-164
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• 1989

서해 금강하구 오식도 부근의 조간대와 조하대역에서 식물플랑크톤의 종별 양적 분포 및 일차생산력과 bacterioplankton(부유박테리아)의 균체수 분포를 1987년 8월부터 1988년 7월 사이에 11회에 걸쳐 조사하였다. 규조류 102종을 포함하여 식물플랑크톤은 총 121 종류를 확인하였고 양적으로는 15-5451 cells/ml 범위였는데, 이들의 시공간적 변화에는 조간대와 조하대의 환경특성 차이가 잘 나타나 있었다. 식물플랑크톤의 일차생산력 (Piopt, mgC/$m^3$/hr)은 0.6-27.32의 범위로서 현존량이 높은 시기와 일차생산력이 높은 시기가 반드시 일치하지는 않았다. 춘계 대번식 후의 4월 조간대역 정점에서는 Piopt와 amylolytic bacterioplankton의 균체수가 모두 극히 낮았다. 정점간 Piopt 비율의 변화에도 역시 조간대와 조하대 역의 환경차이가 잘 나타났다. 식물플랑크톤 현존량과 총 종속영양세균(heterotrophic bacterioplankton) 및 생리적 특성별 bacterioplankton군, 즉 전분분해(amylolytic), 단백질분해(proteolytic) 및 지방분해(lipolytic) 세균과의 관계에는 뚜렷한 경향성이 나타나지 않았으나, 강우량이 집중된 7, 8월에는 각 bacterioplankton의 균체수가 매우 높은 반면 식물플랑크톤의 현존량은 연중 가장 낮아 외래유입(allochthonous) 유기물의 양이 많았음을 시사하였다. 측정된 총 종속영양성 bacterioplankton 및 생리적 특성별 bacterioplankton의 균체수와 Piopt 와의 관계로부터 조사해역에 유입되는 외래성 유기물의 함량 특성을 추정할 수 있었다. 즉, 전분분해 세균과 지방분해 세균은 Piopt와 높은 상관성 (각기 $R^2$값이 0.84 및 0.70) 을 보여 이들이 수중 식물플랑크톤(autochthonous)의 유기물 생산과 직접 관련됨을 알 수 있었고, 단백질분해 세균이나 총 종속영양세균의 분포는 Piopt와 뚜렷한 상관성이 없어 외래유입 유기물 (강수유입, 저층으로부터의 resuspension 등)에 의해 크게 영향을 받는 것으로 판단되었다. 회귀 직선의 기울기로부터 조사 역에서는 Piopt 1mgC/$m^3$/hr 증가당 전분분해 세균이 $9.0{\times}10$ cells/ml, 지방분해세균은$8.0{\times}10$ cells/ml 씩 균체수가 증가하는 것으로 계산되었다.

• 한국작물학회지
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• 제58권3호
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• pp.274-282
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• 2013

아밀로스 함량차이에 따른 배유전분의 이화학적 특성을 파악하기 위해 아밀로스 함량의 차이를 보이는 찰벼, 저 아밀로스, 중간 아밀로스, 고 아밀로스 품종의 외관특성, 화학특성, 호화특성 및 기계적 식미치를 조사하였으며, 그 결과를 요약하면 다음과 같다. 1. 시료들의 아밀로스 함량은 6.3%~30.9% 범위로 아밀로스 함량차이에 따라 4개 그룹 찰벼(A), 저 아밀로스(B), 중간 아밀로스(C), 고 아밀로스(D) 품종군으로 나눌 수 있었으며 각 그룹에 속한 품종들의 단백질함량은 5.8~7.5%로 품종간 차이가 있었으나 아밀로스 함량에 따라 분류된 그룹간 차이는 없었다. 2. 시험재료의 외형적 특성을 보면, 백도는 찰벼 품종군이 가장 높고 저아밀 중간아밀로스 품종군이 가장 낮았다. 현미경도는 고 아밀로스 품종 및 찰벼 품종이 메벼품종과 저 아밀로스 품종보다 대체적으로 낮았다. 알카리 붕괴도는 5.2~6.9의 분포를 보였으며 아밀로스 함량이 증가할수록 붕괴도가 커졌으며, 아밀로스 함량과 알카리 붕괴도 간 매우 높은 양의 상관($r=0.884^{**}$)을 보였다. 3. 아밀로그램 특성을 살펴보면 저 아밀로스 품종군은 호화개시온도가 중간 아밀로스 품종과 비슷한 반면 최고 점도와 강화점도는 높고 최종점도와 치반점도는 낮았다. 고 아밀로스 품종군은 호화개시온도가 다른 품종군에 비해 높고, 최고점도와 최저점도가 매우 낮았으며 최종점도가 상대적으로 높아서 강하점도는 낮고 치반점도는 높은 특성을 보였다. 4. 식미관련 이화학적 특성들 간 상관을 살펴보면 아밀로스 함량은 알카리 붕괴도와 상당히 높은 양의 상관($r=0.88^{**}$)을 Toyo-윤기치와는 높은 음의 상관($r=-0.89^{**}$) 나타냈고, 아밀로그램 특성 중에서는 호화개시온도, 치반점도와 유의한 양의 상관을 보이며, 강하점도와는 음의 상관을 나타냈다.

• 한국해양학회지:바다
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• 제29권1호
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• pp.28-41
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• 2024

탄소수지는 다양한 환경조건에서 식물의 생리적 상태를 평가할 수 있는 중요한 지표 중 하나이다. 우리 동해 연안에 분포하는 새우말의 수온 변화(5-30℃)에 따른 광합성률과 호흡률을 측정하여, 전체 식물 탄소수지의 계절적 변동을 추정하였다. 수온 처리에 따라 최대총광합성률은 유의한 차이를 보였지만, 광합성 효율은 유의한 차이를 보이지 않았다. 새우말의 최대총광합성률은 수온이 상승함에 따라 증가하여 20℃에서 최대값(101.65 μmol O₂ g^-1 DW h^-1)을 보인 후 30℃에서 급격히 감소하였다. 수온 변화에 따른 새우말의 포화광도, 보상광도와 호흡률은 모두 유의한 차이를 보였다. 새우말의 포화광도는 20-25℃까지(121.59-124.50 μmol photons m^-2 s^-1) 증가하다가 30℃에서 급격히 감소하였다. 보상광도와 호흡률은 수온이 증가할수록 점차 증가하였다. 최대총광합성률과 호흡률의 비율은 5℃에서 가장 높았고, 30℃에서 급격히 감소하였다. 광합성 매개변수, 호흡률 및 생체량을 통해서 추정된 새우말 전체 식물의 탄소수지는 겨울과 봄에 증가하고, 여름과 가을에 감소하는 뚜렷한 계절적 경향을 보였으며, 봄에 생장이 가장 활발하고, 수온이 가장 높은 시기에 급격히 감소하는 새우말의 생장 패턴과 일치하였다. 새우말은 늦여름부터 겨울까지 음의 탄소수지를, 봄에서 초여름까지 양의 탄소수지를 보였다. 기후 변화에 의한 지속적인 수온 상승은 우리 동해 연안 암반생태계에 분포하는 잘피생육지의 구조와 기능에 영향을 미칠 것으로 판단된다.