• Title/Summary/Keyword: Dose-rate effects

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The Accumulation of Rare Earth Elements Fertilizer and its Subsequent Effects on Apple Fruit Quality at Harvest and During Storage (희토류비료 시비가 사과 과실내 축적과 수확 및 저장 중 사과품질에 미치는 영향)

  • Zheng, Wei-Wei;Park, Mu-Young;Hirst, Peter;Yoon, Tae-Myung;Chun, Ik-Jo
    • Journal of Bio-Environment Control
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    • v.21 no.4
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    • pp.452-458
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    • 2012
  • Rare earth elements fertilizer and Ca were sprayed on eight-year-old 'Fuji'/M.9 apple trees during two consecutive seasons, and fruit quality was quantified at harvest and 5-month long storing in a commercial cooling house at $4^{\circ}C$ and 80~85% RH. In the first season, single-sprayed of rare earth elements fertilizer showed appreciable accumulations of its elements (La, Pr, Gd, and Nd) in the fruit. In the following season, application of higher doses accumulated higher amount, indicating that the accumulation of rare earth elements was dose-dependent. However, rare earth elements did not affect the accumulations of Ca, Mg, and K in 'Fuji' apple fruit showed that there was no interaction between rare earth elements and these macronutrients. Double-spray of 0.2% rare earth elements increased fruit redness at harvest and had exhibited better color. Although at harvest it did not show significant effects on fruit weight, pulp firmness and titratable acidity (TA), but had pronounced effects on inhibiting fruit softness and retarded decrease of TA during storing. Furthermore, it reduced respiration rate and inhibited ethylene production during storing indicated that rare earth elements may be an alternative for prolonging the shelf life of 'Fuji'/M.9 apple fruit.

Induction of Apoptosis by Methanol Extract of Gloiopeltis furcata in Human Leukemia Cell Line U937 (인체백혈병세포의 증식에 미치는 불등가사리 메탄올 추출물의 영향)

  • Choi, Woo Young;Park, Cheol;Kim, Gi Young;Lee, Won Ho;Bae, Song-Ja;Choi, Yung Hyun
    • Journal of Marine Bioscience and Biotechnology
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    • v.1 no.2
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    • pp.76-83
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    • 2006
  • Epidemiological studies have indicated that the ubiquitous consumption of seaweeds is a protective factor against some types of cancer. Previous results showed that the administration of seaweed powder or extract reduced the incidence rate of chemically induced tumorigenesis using in vivo animal model. Recently, we reported that the extracts of Gloiopeltis furcata, a kind of Korean edible seaweed, caused he cell growth inhibition of various human cancer cell lines, among them methanol extract exhibited a relatively strong antiproliferative activity. However, the molecular mechanisms of this seaweed in malignant cells have been poorly studied until now. To elucidate this problem, we investigated the effects of methanol extract of G. furcata (MEGF) on the growth inhibition in several human cancer cell lines, and further we analyzed the effects of this extract were tested on the activity of apoptosis induction in human leukemic cells. The results demonstrated that MEGF treatment resulted in the morphological changes and the growth inhibition in a dose-dependent manner. Furthermore, MEGF potently suppresses the growth of human leukemic U937 cells by induction of apoptosis, which was associated with induction of cyclin-dependent kinase inhibitor p21(WAF1/CIP1) in a tumor suppressor p53-independent fashion and up-regulation of Fas/FasL system. Further studies will be needed to identify the active compounds that confer the anticancer activity of MEGF. Once such compounds are identified, the mechanisms by which they exert their effects can begin to be characterized.

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ᴅ-Xylose as a sugar complement regulates blood glucose levels by suppressing phosphoenolpyruvate carboxylase (PEPCK) in streptozotocin-nicotinamide-induced diabetic rats and by enhancing glucose uptake in vitro

  • Kim, Eunju;Kim, Yoo-Sun;Kim, Kyung-Mi;Jung, Sangwon;Yoo, Sang-Ho;Kim, Yuri
    • Nutrition Research and Practice
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    • v.10 no.1
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    • pp.11-18
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    • 2016
  • BACKGROUND/OBJECTIVES: Type 2 diabetes (T2D) is more frequently diagnosed and is characterized by hyperglycemia and insulin resistance. $\small{D}$-xylose, a sucrase inhibitor, may be useful as a functional sugar complement to inhibit increases in blood glucose levels. The objective of this study was to investigate the anti-diabetic effects of $\small{D}$-xylose both in vitro and stretpozotocin (STZ)-nicotinamide (NA)-induced models in vivo. MATERIALS/METHODS: Wistar rats were divided into the following groups: (i) normal control; (ii) diabetic control; (iii) diabetic rats supplemented with a diet where 5% of the total sucrose content in the diet was replaced with $\small{D}$-xylose; and (iv) diabetic rats supplemented with a diet where 10% of the total sucrose content in the diet was replaced with $\small{D}$-xylose. These groups were maintained for two weeks. The effects of $\small{D}$-xylose on blood glucose levels were examined using oral glucose tolerance test, insulin secretion assays, histology of liver and pancreas tissues, and analysis of phosphoenolpyruvate carboxylase (PEPCK) expression in liver tissues of a STZ-NA-induced experimental rat model. Levels of glucose uptake and insulin secretion by differentiated C2C12 muscle cells and INS-1 pancreatic ${\beta}$-cells were analyzed. RESULTS: In vivo, $\small{D}$-xylose supplementation significantly reduced fasting serum glucose levels (P < 0.05), it slightly reduced the area under the glucose curve, and increased insulin levels compared to the diabetic controls. $\small{D}$-xylose supplementation enhanced the regeneration of pancreas tissue and improved the arrangement of hepatocytes compared to the diabetic controls. Lower levels of PEPCK were detected in the liver tissues of $\small{D}$-xylose-supplemented rats (P < 0.05). In vitro, both 2-NBDG uptake by C2C12 cells and insulin secretion by INS-1 cells were increased with $\small{D}$-xylose supplementation in a dose-dependent manner compared to treatment with glucose alone. CONCLUSIONS: In this study, $\small{D}$-xylose exerted anti-diabetic effects in vivo by regulating blood glucose levels via regeneration of damaged pancreas and liver tissues and regulation of PEPCK, a key rate-limiting enzyme in the process of gluconeogenesis. In vitro, $\small{D}$-xylose induced the uptake of glucose by muscle cells and the secretion of insulin cells by ${\beta}$-cells. These mechanistic insights will facilitate the development of highly effective strategy for T2D.

Effects of dietary flavonoids on performance, blood constituents, carcass composition and small intestinal morphology of broilers: a meta-analysis

  • Prihambodo, Tri Rachmanto;Sholikin, Muhammad Miftakhus;Qomariyah, Novia;Jayanegara, Anuraga;Batubara, Irmanida;Utomo, Desianto Budi;Nahrowi, Nahrowi
    • Animal Bioscience
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    • v.34 no.3_spc
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    • pp.434-442
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    • 2021
  • Objective: This study aims to evaluate the influence of dietary flavonoids on the growth performance, blood and intestinal profiles, and carcass characteristics of broilers by employing a meta-analysis method. Methods: A database was built from published studies which have reported on the addition of various levels of flavonoids from herbs into broiler diets and then monitored growth performance, blood constituents, carcass proportion and small intestinal morphology. A total of 42 articles were integrated into the database. Several forms of flavonoids in herbs were applied in the form of unextracted and crude extracts. The database compiled was statistically analyzed using mixed model methodology. Different studies were considered as random effects, and the doses of flavonoids were treated as fixed effects. The model statistics used were the p-values and the Akaike information criterion. The significance of an effect was stated when its p-value was <0.05. Results: Dietary flavonoids increased (quadratic pattern; p<0.05) the average daily gain of broilers in the finisher phase. There was a reduction (p<0.01) in the feed conversion ratio of the broilers both in the starter (linear pattern) and finisher phases (quadratic pattern). The mortality rate tended to decrease linearly (p<0.1) with the addition of flavonoids, while the carcass parameter was generally not influenced. A reduction (p<0.001) in cholesterol and malondialdehyde concentrations (both linearly) was observed, while super oxide dismutase activity increased linearly (p<0.001). Increasing the dose of flavonoids increased (p<0.01) the villus height (VH) and villus height and crypt depth (VH:CD) ratio (p<0.05) in the duodenum. Similarly, the VH:CD ratio was elevated (p<0.001) in the jejunum following flavonoid supplementation. Conclusion: Increasing levels of flavonoids in broilers diet leads to an improvement in growth performance, blood constituents, carcass composition and small intestinal morphology.

Effects of Alisma canaliculatum Extract in Pacemaker Potential of Intestinal Interstitial cells of Cajal in mice (생쥐 소장 및 대장 카할세포의 자발적 탈분극에서 택사의 효과에 관한 비교연구)

  • Kwon, Hyo Eun;Park, Dong Suk;Kim, Jeong Nam;Kim, Byung Joo
    • Herbal Formula Science
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    • v.30 no.2
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    • pp.37-44
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    • 2022
  • Objectives : The purpose of this study was to examine the effects of Alisma canaliculatum Extract (ACE) on pacemaker potentials of small and large intestinal interstitial Cells of Cajal (ICC) in mice. Methods : We used enzymatic digestions to dissociate the ICC in the small and large intestine in mice. The whole-cell patch-clamp method was used to record pacemaker potentials in ICC. Results : 1. The ICC generated the pacemaker potentials in small intestine in mice. ACE (0.1-1mg/ml) induced membrane depolarization and decreased frequency with concentration-dependent manners. 2. Pretreatment with a Ca2+ free solution, Na+ 5 mM solution or 2-APB, a nonselective cation channel blocker, stopped the small intestinal ICC pacemaker potentials. In the case of Ca2+-free solution, Na+ 5 mM solution or 2-APB, ACE had no effects on the membrane depolarizations in small intestinal ICC. 3. The ICC generated the pacemaker potentials in large intestine in mice. Membrane depolarization appears regularly in the small intestine, but irregularly in the large intestine. ACE induced membrane depolarization (0.1-1mg/ml) and increased frequency (0.1-0.5mg/ml). 4. Pretreatment with a Ca2+ free solution, Na+ 5 mM solution or 2-APB, stopped the large intestinal ICC pacemaker potentials. In the case of Ca2+-free solution, Na+ 5 mM solution or 2-APB, ACE depolarized the membrane depolarizations in large intestinal ICC. 5. In mice, intestinal transit rate (ITR) values were dose-dependently decreased by the intragastric administration of ACE. Conclusions : These results suggest that ACE can regulate the pacemaker activity of ICC and the reaction by ACE is different from the small and large intestinal ICC, and the control of the intestinal motion by ACE may be caused by many complex processes.

Effects of Administration of Oxytocin Antagonist on Implantation and Pregnancy Rates in Patients with Repeated Failure of IVF/ICSI Treatment (체외수정시술의 반복적인 실패 환자에서 옥시토신 길항제 주입이 착상 및 임신에 미치는 영향)

  • Ahn, Jun-Woo;Kim, Chung-Hoon;Kim, So-Ra;Jeon, Gyun-Ho;Kim, Sung-Hoon;Chae, Hee-Dong;Kang, Byung-Moon
    • Clinical and Experimental Reproductive Medicine
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    • v.36 no.4
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    • pp.275-281
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    • 2009
  • Objective: This study was performed to evaluate the effect of oxytocin antagonist on the outcome of IVF/ICSI cycles in infertile patients with repeated failure of IVF/ICSI treatment. Method: Forty patients who had experienced two or more failures of IVF/ICSI treatment without low ovarian reserve, were recruited for this prospective randomized study. All patients received controlled ovarian stimulation (COS) using GnRH antagonist multidose protocol (MDP). For the intervention group, intravenous administration of atosiban (mixed vasopressin $V_{1A}$/oxytocin antagonist) started with a bolus dose 6.75 mg one hour before embryo transfer (ET) and continued at an infusion rate of 18 mg/hour. After ET, administered atosiban was reduced to 6 mg/hour and continued for 2 hours. The main efficacy endpoints were clinical pregnancy rate and implantation rate. Results: Patients' characteristics were comparable in the intervention and control groups. COS parameters and IVF results were also similar. The number of uterine contractions for 3 minutes measured just before ET was significantly lower in the intervention group than control group ($3.5{\pm}1.4$ vs $8.7{\pm}2.2$, p<0.001). While there was no statistically significant difference in the clinical pregnancy rate between control group and intervention group (20.0% and 40.0%, p=0.168), the implantation rate was significantly higher in the intervention group, with 16.9% (11/65) compared with 6.0% (4/67) in the control group (p=0.047). There were no differences in ectopic pregnancy rate and miscarriage rate between the two groups. Conclusion: This study demonstrates that administration of oxytocin antagonist during ET can improve the implantation rate probably by decreasing the frequency of uterine contractions in infertile patients undergoing IVF/ICSI treatment.

Effect of Noise on Density Differences of Tissue in Computed Tomography (컴퓨터 단층촬영의 조직간 밀도차이에 대한 노이즈 영향)

  • Yang, Won Seok;Son, Jung Min;Chon, Kwon Su
    • Journal of the Korean Society of Radiology
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    • v.12 no.3
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    • pp.403-407
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    • 2018
  • Currently, the highest cancer death rate in Korea is lung cancer, which is a typical cancer that is difficult to detect early. Low-dose chest CT is being used for early detection, which has a greater lung cancer diagnosis rate of about three times than regular chest x-ray images. However, low-dose chest CT not only significantly reduces image resolution but also has a weak signal and is sensitive to noise. Also, air filled lungs are low-density organs and the presence of noise can significantly affect early diagnosis of cancer. This study used Visual C++ to set a circle inside a large circle with a density of 2.0, with a density of 1.0, which is the density of water, in which five small circle of mathematics have different densities. Gaussian noise was generated by 1%, 2%, 3%, and 4% respectively to determine the effect of noise on the mean value, the standard deviation value, and the relative noise ratio(SNR). In areas where the density difference between the large and small circles was greatest in the event of 1 % noise, the SNR in the area with the greatest variation in noise was 4.669, and in areas with the lowest density difference, the SNR was 1.183. In addition, the SNR values can be seen to be high if the same results are obtained for both positive and negative densities. Quality was also clearly visible when the density difference was large, and if the noise level was increased, the SNR was reduced to significantly affect the noise. Low-density organs or organs in areas of similar density to cancers, will have significant noise effects, and the effects of density differences on the probability of noise will affect diagnosis.

The Role of Adenosine Receptors on Acetylcholine Release in the Rat Striatum

  • Kim, Do-Kyung;Kim, Hyeon-A;Choi, Bong-Kyu
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.1
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    • pp.1-12
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    • 1997
  • As it has been reported that the depolarization induced acetylcholine (ACh) release is modulated by activation of presynaptic $A_1$ adenosine heteroreceptor and various evidence suggest that indicate the $A_2$ adenosine receptor is present in the striatum, this study was undertaken to delineate the role of adenosine receptors on the striatal ACh release. Slices from the rat striatum were equilibrated with $[^3H]$choline and then the release amount of the labelled product, $[^3H]$ACh, which was evoked by electrical stimulation (rectangular pulses, 3 Hz, 2 ms, 24 mA, $5\;Vcm^{-1}$, 2 min), was measured, and the influence of various agents on the evoked tritium outflow was investigated. And also, quantitative receptor autoradiography and drug-receptor binding assay were performed in order to confirm the presence and characteristics of $A_1$ and $A_2$ adenosine receptors in the rat striatum. Adenosine $(10{sim}100\;{mu}M)$ and $N^6$-cyclopentyladenosine (CPA, $1{sim}100\;{mu}M)$ decreased the $[^3H]$ACh release in a dose-dependent manner without changing the basal rate of release in the rat striatum. The reducing effects of ACh release by adenosine and CPA were abolished by 8-cyclopentyl-1,3-dipropy-Ixanthine (DPCPX, 2 ${mu}M$), a selective $A_1$, adenosine receptor antagonist, treatment. The effect of adenosine was potentiated markedly by 3,7-dimethyl-1-propargylxanthine (DMPX, 10 ${mu}M$), a specific $A_2$ adenosine receptor antagonist. 2-P-(2-carboxyethyl)phenethylamimo-5'-N- ethylcarboxamidoadenosine hydrochloride (CGS-21680C), in concentrations ranging from 0.01 to 10 ${mu}M$, a recently introduced potent $A_2$ adenosine receptor agonist, increased the $[^3H]$ACh release in a dose related fashion without changing the basal rate of release. These effects were completely abolished by DMPX $(10\;{mu}M)$. In autoradiograrhy experiments, $[^3H]$2-chloro-$N^6$-cyclopentyladenosine ($[^3H]$ CCPA) bindings were highly localized in the hippocampus and the cerebral cortex. Additionally, lower levels of binding were found in the striatum. However, $[^3H]$CGS-21680C bindings were highly localized in the striatal region with the greatest density of binding found in the caudate nucleus and putamen. Lower levels of binding were also found in the nucleus accumbens and olfactory tubercle. In drug-receptor binding assay, binding of $[^3H]$ CCPA to $A_1$ adenosine receptors of rat striatal membranes was inhibited by CPA ($K_i$ = 1.6 nM) and N-ethylcarboxamidoadenosine (NECA, $K_i$ = 12.9 nM), but not by CGS-21680C ($K_i$ = 2609.2 nM) and DMPX ($K_i$ = 19,386 nM). In contrast, $[^3H]$CGS-21680C binding to $A_2$ denosine receptors was inhibited by CGS-21680C ($K_i$ = 47.6 nM) and NECA ($K_i$ = 44.9 nM), but not by CPA ($K_i$ = 2099.2 nM) and DPCPX ($K_i$ = 19,207 nM). The results presented here suggest that both types of $A_1$ and $A_2$ adenosine heteroreceptors exist and play an important role in ACh release in the rat striatal cholinergic neurons.

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A Theoretical Study for Estimation of Oxygen Effect in Radiation Therapy (방사선 조사시 산소가 세포에 미치는 영향의 이론적 분석)

  • Rena J. Lee;HyunSuk Suh
    • Progress in Medical Physics
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    • v.11 no.2
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    • pp.157-165
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    • 2000
  • Purpose: For estimation of yields of l)NA damages induced by radiation and enhanced by oxygen, a mathematical model was used and tested. Materials and Methods: Reactions of the products of water radiolysis were modeled as an ordinary time dependant equations. These reactions include formation of radicals, DNA damage, damage repair, restitution, and damage fixation by oxygen and H-radical. Several rate constants were obtained from literature while others were calculated by fitting an experimental data. Sensitivity studies were performed changing the chemical rate constant at a constant oxygen number density and varying the oxygen concentration. The effects of oxygen concentration as well as the damage fixation mechanism by oxygen were investigated. Oxygen enhancement ratio(OER) was calculated to compare the simulated data with experimental data. Results: Sensitivity studies with oxygen showed that DNA survival was a function of both oxygen concentration and the magnitude of chemical rate constants. There were no change in survival fraction as a function of dose while the oxygen concentration change from 0 to 1.0 x 10$^{7}$ . When the oxygen concentration change from 1.0 $\times$ 107 to 1.0 $\times$ 101o, there was significant decrease in cell survival. The OER values obtained from the simulation study were 2.32 at 10% cell survival level and 1.9 at 45% cell survival level. Conclusion: Sensitivity studies with oxygen demonstrated that the experimental data were reproduced with the effects being enhanced for the cases where the oxygen rate constants are largest and the oxygen concentration is increased. OER values obtained from the simulation study showed good agreement for a low level of cell survival. This indicated that the use of the semi-empirical model could predict the effect of oxygen in cell killing.

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Toxic effect of chlorothalonil, an antifouling agent, on survival and population growth rate of a marine rotifer, Brachionus plicatilis (해산 로티퍼(Brachionus plicatilis)의 생존율 및 개체군 성장률을 이용한 신방오물질(Chlorothalonil)의 독성영향)

  • Heo, Seung;Lee, Ju-Wook;Choi, Hoon;Yoon, Sung-Jin;Kwon, Ki-Young;Hwang, Un-Ki;Park, Yun-Ho
    • Korean Journal of Environmental Biology
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    • v.39 no.3
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    • pp.390-398
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    • 2021
  • In this study, the toxicity of chlorothalonil was investigated using survival rate and population growth rate of a marine rotifer, Brachionus plicatilis, typically used in live food in marine aquaculture systems. The survival rate of B. plicatilis was determined after 24 h of exposure to chlorothalonil (0.010-0.156 mg L-1). Population growth rate of B. plicatilis was calculated after 72 h of exposure to chlorothalonil (0.078-1.250 mg L-1). The survival rate and population growth rate of B. plicatilis exposed to chlorothalonil in single-dose toxicity assessment showed concentration-dependent reductions. Survival rates of B. plicatilis exposed to chlorothalonil had the following values: NOEC, 0.020mg L-1; LOEC, 0.039 mg L-1; and EC50, 0.057 mg L-1. Population growth rate of B. plicatilis exposed to chlorothalonil had the following values: NOEC, 0.156 mg L-1; LOEC, 0.313 mg L-1; and EC50, 0.506 mg L-1. When the residual concentration of chlorothalonil in the marine coastal area was more than 0.039 mg L-1, it had a toxic effect on B. plicatilis, a zooplankton. This paper provides toxicity values that can be used as baseline data for organizing environmental standards of chlorothalonil. It also provides insight into toxic effects of chlorothalonil on other non-target organisms.