• 제목/요약/키워드: N and P limitation

검색결과 142건 처리시간 0.028초

담수산 미세조류로부터 생리활성물질의 탐색 (Screening of Bioactive Materials from Freshwater Microalgae)

  • 이완석;최애란;안치용;오현철;안종석;오희목
    • ALGAE
    • /
    • 제19권3호
    • /
    • pp.271-276
    • /
    • 2004
  • One hundred and fifty four micro algal strains, newly isolated from nationwide freshwaters in Korea, were screened for their anticancer, ant diabetic, and antibiotic activities. The micro algal strains were cultured with different nutritional conditions that were divided into 4 groups as follows; a normal Allen medium, nitrogen (N)-limited medium, phosphorus (P)-limited medium, and N and P-limited medium. Algal biomass was extracted with a mixture of acetone:H₂O (1:1, v:v) and the extracts were used for the screening of bioactive materials. Anticancer, ant diabetic, and antibiotic materials were screened by the methods of vaccinia Hl-related protein tyrosine phosphates (VHR DS-PTPase) inhibition, protein tyrosine phosphates 1B (PTP1B) inhibition, and paper disk. The inhibition activity of VHR DS-PTPase was observed in 18 strains, having a maximum 79% inhibition from Anabaena affinis and the inhibition activity of PTP1B was observed in 9 strains, having a maximum 97% from Sphaerocystis schroeteri. Microcystis aeruginosa incubated in an N and P-limited medium showed antibiotic activity in 8 species out of 13 pathogenic bacteria. As a whole, it seemed that the stressed condition such as N and/or P limitation increased the production of bioactive materials in micro algae.

Scenedesmus quadricauda에 의한 광합성 산물의 세포 외 배출에 미치는 환경요인의 영향 (Effects of environmental factors on the extracellular release of photosynthetic products by scenedesmus quadricauda)

  • 강찬수;김상종;이인권;권오섭
    • 미생물학회지
    • /
    • 제27권4호
    • /
    • pp.373-377
    • /
    • 1989
  • The effects of environmental factors on the extracellular release of organic carbon by Scenedesmus qudricauda were studied. The PER (percentage extracellular release) was greater at high temperature and at high concentration of nitrogen and phosphate. The PER variation according to the change of M/P ratio showed high values at each extreme N/P ratio. This result suggested that the limitation of nitrogen or phosphorous resulted in the accumulation of carbohydrates as photosynthetic products, and the products in high concentration were excreted through algal cell membrane.

  • PDF

오십견 환자의 치료에 있어서 저주파자극기의 효과 (Efficacy of Low Frequency Stimulator in Patients with Frozen Shoulder)

  • 임윤희;이평복;서명신;박상현;오용석;박지현
    • The Korean Journal of Pain
    • /
    • 제18권2호
    • /
    • pp.156-160
    • /
    • 2005
  • Background: Frozen shoulder is not an uncommon disease, which is associated with chronic pain and joint movement limitation. However, there are numerous devices to assist in the treatment of shoulder pain, but their efficacy has not been proven and their use remains immensely controversial. Therefore, a randomized clinical study was conducted to determine the effectiveness of a low-frequency stimulator for the treatment of frozen shoulder. Methods: A randomized clinical trial was carried out on 40 patients with frozen shoulder, with 40 patients assigned to two groups; a control treatment group (group C, n = 20) and a low frequency stimulator application group (group T, n = 20). Both groups were given a routine treatment modality, such as trigger point injection, intramuscular stimulation or suprascapular nerve block etc. The level of the shoulder pain was evaluated using a 100mm VAS (visual analog scale) at each visit, with the limitation in the range of motion simultaneously evaluated. Results: All the subjects improved after treatment, with the VAS scores after termination of treatment showed a statistically significant reduction (P < 0.05). However, there was no significant difference between the two groups. One month after termination of 5 cycles of treatment, group T maintained their improved state, whereas the pain in some of those in group C reemerged, which also showed a statistically significant difference (P < 0.05). The limitation in the range of motion improved, with most subjects able to resume daily activity. Conclusions: Although the low frequency stimulation provided no more pain relief than routine treatment, the effect was significantly prolonged. From this result, low frequency stimulation can be considered to aide the therapeutic effect of classical frozen shoulder therapy.

L-Carnitine의 수준이 다른 Lysine 제한식이 섭취가 비만유도 성숙쥐의 체중과 지질대사에 미치는 영향 (Effect of Lysine-Limited Diets Containing Different Levels of L-Carnitine on Body Weight and Lipid Metabolism in Obesity-Induced Adult Rats)

  • 김자경;김미경
    • Journal of Nutrition and Health
    • /
    • 제40권2호
    • /
    • pp.118-129
    • /
    • 2007
  • This study was performed to investigate the effect of lysine-limited diets containing different levels of L-carnitine on body weight and lipid metabolism in obesity-induced adult rats. Eight-month-old male Sprague-Dawley rats (n = 90) were raised for one month with high fat diet (40% fat as calorie) to induce obesity. After induction of obesity, rats weighing 739.5 g were randomly blocked into three groups according to the body weight and raised for eight weeks with control diet (Co), 50% lysine-limited diet (-L), 50% lysine limitation with 0.3% pivalate diet (-L + P). Each of three groups was allotted to 0.0% L-carnitine (0.0% CT), 0.5% L-carnitine (0.5% CT) and 2.5% L-carnitine (2.5% CT) groups, respectively. The levels of AST, ALT, total protein and albumin in plasma were within the normal range. Daily food intake and calorie intake tended to be lower in 2.5% CT groups than those of other groups regardless lysine limitation or pivalate intake. And body weight gain and calorie efficiency ratio (weight gain (g) /calorie intake (100 kcal)) were significantly the lowest in 2.5% CT groups among all experimental groups regardless of lysine limitation or pivalate intake. The weights of perirenal, epididymal fat pads and brown adipose tissue in 2.5% CT groups were significantly lower than 0.0% CT groups. Plasma total lipid, triglyceride, total cholesterol concentrations in all groups were not significant by experimental compound. HDL-cholesterol concentrations in -L + P +2.5% CT group were highest in -L + P groups. Levels of hepatic total lipid, triglyceride and total cholesterol in 2.5% CT groups were tend to be lower those than in 0.0% CT groups regardless of dietary lysine limitation and pivalate intake. Fecal total lipid excretions of 2.5% CT groups were significantly lower than in 0.0% CT groups in all experimental groups. But fecal triglyceride excretions of 2.5% CT groups were significantly higher than 0.0% CT groups regardless of lysine limitation and pivalate. In conclusion, there was no difference on body weight and lipid metabolism by dietary lysine limitation and pivalate intake. And feeding of 2.5% L-carnitine was more effective than feeding of 0.5% L-carnitine and 0.0% L-carnitine in reduction of body weight, body fat and lipid metabolism.

Modifications of nutrient regime, chlorophyll-a, and trophic state relations in Daechung Reservoir after the construction of an upper dam

  • Ingole, Neha P.;An, Kwang-Guk
    • Journal of Ecology and Environment
    • /
    • 제40권1호
    • /
    • pp.24-33
    • /
    • 2016
  • Background: Previous numerous studies on watershed scale demonstrated that the constructions of upper dams may influence the below dams due to modifications of flow regime and nutrient inputs. Little is known about how the dam constructions influence the downstream lakes or reservoirs in the regional scale. This study demonstrates how the construction of upper dam (i.e., Yongdam Dam) influences nutrient regime, trophic relations, and empirical models in Daechung Reservoir (DR). Yongdam Dam was constructed at the upstream region of DR in year 2000. Results: The analysis of hydrological variables showed that inflow and discharge in the DR were largely reduced after the year 2000. The construction of upper dam construction also resulted in increases of water temperature, pH and conductivity (as an indicator of ionic content) in the DR. Empirical models of TP-CHL and N:P ratio-CHL suggested that stronger responses of CHL to the phosphorus were evident after the upper dam construction, indicating that algal production at a unit phosphorus increased after the upper dam construction. Mann-Kendall tests on the relations of N:P ratios to TN showed weak or no relations ($t_{au}=-0.143$, z = -0.371, p = 0.7105) before the dam construction, while the relation of N:P ratios to TP showed strong in the periods of before- ($t_{au}=-0714$, z = -2.351, p = 0.0187) and after the construction ($t_{au}=-0.868$, z = -4.270, p = 0.0000). This outcome indicates that TP is key determinant on N:P ratios in the reservoir. Scatter Plots on Trophic State Index Deviations (TSIDs) of "TSI(SD) - TSI(CHL)" against "TSI(TP) - TSI(CHL)" showed that the dominance of clay turbidity or light limitation was evident before the upper dam construction [TSI(TP) - TSI(CHL) > 0 and TSI(SD) - TSI(CHL) > 0] and phosphorus limitation became stronger after the dam construction [(TSI(TP) - TSI(CHL) < 0 and TSI(SD) - TSI(CHL) > 0]. Conclusions: Overall, our analysis suggests that the upper dam construction modified the response of trophic components (phytoplankton) to the nutrients or nutrient ratios through the alteration of flow regime, resulting in modifications of ecological functions and trophic relations in the low trophic levels.

저전압 저전력 CMOS복합 트랜스컨덕터 설계 (Design of A CMOS Composite Transconductor for Low-voltage Low-power)

  • 이근호
    • 대한전자공학회논문지SD
    • /
    • 제39권10호
    • /
    • pp.65-73
    • /
    • 2002
  • 두 가지 방식을 이용하여 넓은 동작 영역을 갖는 복합 트랜지스터를 제안하고, 이를 이용하여 새로운 트랜스컨덕터를 설계하였다. 저전압 저전력 특성을 위해 첫 번째 제안한 복합 트랜지스터 I은 P형 폴디드(P-type folded) 복합 트랜지스터를 이용하였으며, 복합 트랜지스터Ⅱ는 복합 다이오드 방식을 이용하여 문턱전압을 감소하였다. 이와 더불어 제안된 트랜지스터가 전류원에 의해 동작 영역이 제한되는 원인을 고찰하였으며, 응용 회로로 설계된 트랜스컨덕터의 특성을 해석하였다. 설계된 회로는 0.2㎛ CMOS n-well 공정 파라미터를 이용하여 HSPICE 시뮬레이션 하였다.

견관절의 유착성 관절낭염 환자에 대한 자가신장운동의 효과 (The Effect of Self Stretching Exercise in Patients with Shoulder Adhesive Capsulitis)

  • 서병도;신형수
    • The Journal of Korean Physical Therapy
    • /
    • 제22권1호
    • /
    • pp.19-26
    • /
    • 2010
  • Purpose: The purpose of this study was to compare the effectiveness of (a) a self stretching exercise (SSE) maintained below the level of pain with (b) physical therapy (PT) performed without pain limitation in patients with adhesive capsulitis. Methods: Forty-three subjects with frozen shoulder were recruited. Subjects were randomly assigned to one of two groups - an experimental group (SSE group, $n_1=18$) and a control group (PT group, $n_2=25$). The duration of each intervention was five weeks. We assessed night pains, range of motion (ROM), and shoulder function. Results: Overall, subjects in both groups improved over five weeks (p<0.05). The change in the PT group was greater (p<0.05) Conclusion: SSE carried out under the pain threshold may be used to treat patients with adhesive capsulitis SSE can be prescribed with PT as part of a home program or of group management.

개선된 동작영역을 갖는 복합 트랜지스터 설계 (Design of Composite Transistors with an Improved Operating Region)

  • 이근호;유영규
    • 한국통신학회논문지
    • /
    • 제28권3A호
    • /
    • pp.185-191
    • /
    • 2003
  • 본 논문에서는 문턱 전압의 감소에 의해 넓은 동작 영역을 갖는 새로운 구조의 트랜지스터를 제안하였다. 문턱 전압을 감소시키기 위해 제안된 복합 트랜지스터Ⅰ은 P형 폴디드(P-type folded) 복합 트랜지스터를 이용하였고, 복합 트랜지스터Ⅱ는 제너 다이오드를 이용하였다. 제안된 트랜지스터가 전류원에 의해 동작 영역이 제한되는 현상을 고찰하여 검증하였으며, 제안된 회로들은 0.25㎛ CMOS n-well 공정 파라미터를 이용하여 2.5V 공급 전압하에서 Hspice 시뮬레이션을 통해 그 특성을 검증하였다.

아쿠아로빅 운동이 노인 여성의 신체구성, 체력 및건강관련 삶의 질(SF-36)에 미치는 영향 (Effects of Aquarobics Exercise on Body Composition, Fitness andHealth Related Quality of Life(SF-36) in Elderly Women)

  • 소위영;홍지영;전은진;최대혁;김기홍
    • 한국노년학
    • /
    • 제30권3호
    • /
    • pp.683-694
    • /
    • 2010
  • 본 연구는 아쿠아로빅 운동이 노년 여성에게 미치는 신체적, 심리적 효과를 동시에 관찰함으로써, 노인운동처방에 관한 다각도적인 기초자료를 제공하고자 하였다. 본 연구의 피험자는 I시 Y구 보건소 아쿠아로빅 운동프로그램에 참가를 희망하는 60-70대 노년 여성으로 운동군 25명, 통제군 30명으로 분류하였다. 아쿠아로빅 운동은 8주 동안 주 2회 최대여유심박수 40~70%의 운동강도로 실시하여, 운동 전후의 신체구성, 체력 및 건강관련 삶의 질(SF-36)의 변화를 측정하였다. 아쿠아로빅 운동 전후 신체구성의 체중(p=0.044), 체질량지수(p=0.038) 및 체지방률(p=0.005)의 모든 변인에서 시점에 따라 집단 간에 유의한 차이가 나타났다. 체력변인의 의자에서 일어섰다 앉기, 의자앉아 앞으로 굽히기는 시점에 따라 집단 간에 유의한 차이가 나타나지 않았으나, 2분 제자리걷기(p=0.002), 덤벨들기(p=0.005), 등 뒤에서 손잡기(p=0.023), 244cm 왕복걷기(p<0.001)는 시점에 따라 집단 간에 유의한 차이가 나타났다. 건강관련 삶의 질(SF-36)의 신체기능, 신체역할제한, 감정역할제한, 사회적 기능, 정신건강, 피로는 시점에 따라 집단 간에 유의한 차이가 나타나지 않았으나, 신체통증(p=0.039)과 일반적인 건강(p=0.024)은 시점에 따라 집단 간에 유의한 차이가 나타났다. 노년 여성에게 있어서 아쿠아로빅 운동은 신체구성의 개선과 체력의 향상을 위한 좋은 운동형태가 될 수 있음을 확인할 수 있었으나, 건강관련 삶의 질(SF-36)에 관하여서는 8가지 요인 중 2가지의 일부 요인에서만 긍정적인 영향이 나타났음을 확인할 수 있었다.

기상자료의 결측과 산정에 따른 기준작물 증발산량 공식의 비교 평가 (Assessment of Reference Evapotranspiration Equations for Missing and Estimated Weather Data)

  • 윤푸른;최진용
    • 한국농공학회논문집
    • /
    • 제60권3호
    • /
    • pp.15-25
    • /
    • 2018
  • Estimating the reference evapotranspiration is an important factor to consider in irrigation system design and agricultural water use. However, there is a limitation in using the FAO Penman-Monteith (FAO P-M) equation, which requires various meteorological data. The purpose of this study is to compare three reference evapotranspiration (ETo) equations in the case of meteorological data missing for 11 study weather stations. Firstly, the FAO P-M equation is used for reference potential evapotranspiration estimation with the actual solar radiation data $R_n$ and the actual vapor pressure $e_a$. Then, in the case of $R_n$, and $e_a$ are missed, the reference evapotranspirations applying FAO P-M, Priestley-Taylor (P-T), Hargreaves (HG) equation were calculated using other meteorological factors. Secondly, MAE, RMSE, $R^2$ were calculated to compare ETo relationship from the ETo equations. From the results, ETo with Hargreaves equation in coastal areas and the Priestley-Taylor equation in the inland areas showed relatively high correlation with FAO P-M when $e_a$ data is missed. In the case of $R_n$ data is missed or two weather data, $e_a$, and $R_n$ data are all missed, $R^2$ value in Priestley-Taylor equation was highest in coastal areas, and $R^2$ values in Hargreaves equation were the high values for 7 inland areas. The results of sensitivity analysis showed that net radiation was the most sensitive for P-T and HG equation, and for FAO P-M, the most sensitive factor was net radiation and relative humidity, air temperature and wind speed were follows. Therefore, in considering of the accessibility to the coast, the types of the missing wether data, and the correlation and the magnitude of error, the reference evapotranspiration equations would be selected in sense of different conditions.