• Title/Summary/Keyword: period-2 solution

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ASYMPTOTIC BEHAVIOR OF SOLUTIONS FOR DIFFERENCE EQUATION $x_{n+1}\;=\;{\alpha}\;+\;\beta{x_{n-1}}^{p}/{x_n}^p$

  • Liu, Zhaoshuang;Zhang, Zhenguo
    • The Pure and Applied Mathematics
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    • v.11 no.1
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    • pp.15-22
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    • 2004
  • In this paper, we investigate asymptotic stability, oscillation, asymptotic behavior and existence of the period-2 solutions for difference equation $x_{n+1}\;=\;{\alpha}\;+\;\beta{x_{n-1}}^{p}/{x_n}^p$ where ${\alpha}\;{\geq}\;0,\;{\beta}\;>\;0.\;$\mid$p$\mid$\;{\geq}\;1$, and the initial conditions $x_{-1}\;and\;x_0$ are arbitrary positive real numbers.

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An experimental study on the myocardial protection effect of the methylprednisolone mixed GIK solution (Methylprednisolone을 첨가한 GIK용액의 심근보호효과에 관한 실험적 연구)

  • 유시원
    • Journal of Chest Surgery
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    • v.17 no.4
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    • pp.574-586
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    • 1984
  • Although corticosteroid have been shown to stabilize lysosomal membranes and prevent release of hydrolytic enzymes, the mechanism of membrane stabilization remains obscure. This study described functional assessment of efficiency of methylprednisolone in GIK solution by using a isolated Rat Heart Model. Isolated rat heart were subjected to a 2-minute period of coronary infusion with a cold GIK or methylprednisolone mixed cold GIK solution immediately before and also at the midpoint of a 60-minute period of hypothermic [$10{\pm}1^{\circ}C$] ischemic arrest. The result of this were as follow: 1.Spontaneous heart beat after ischemic arrest occurred 11 second later after Langendorffs reperfusion in the methylprednisolone mixed GIK group and 14 second later in the control group. 2.The percentage of recoveries of heart rate at 30 minute after postischemic working heart perfusion was 88.6\ulcorner.6% in the methylprednisolone mixed GIK group. This percentage of recovery was not significantly greater than the control group. 3.The percentage of heart function at 30 minute after postischemic working heart perfusion were; peak aortic pressure $90.8{\pm}4.5%$ coronary flow $87.5{\pm}1.45$ and aortic flow $74.9{\pm}11.8%$ in the methylprednisolone mixed GIK group. This percentage of recovery was significantly greater than the control group. [p<0.05]

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Effect of Equilibration Tine and Developmental Stages on the Survival of Mouse Embryos Cryopreserved by Vitrification in EFS Solution (Ethylene Glycol을 이용한 유리화 동결시 평형시간과 배 발달단계별 생쥐 배의 생존성)

  • 공일근;정기화;노규진;조성근;이은봉;박충생
    • Journal of Embryo Transfer
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    • v.9 no.2
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    • pp.173-180
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    • 1994
  • The present experirnents on cryopreservation were carried out to investigate effect of solution toxicity, equilibration time and cell stages on the post-thaw survival of mouse morulae and blastocyst embryos cryopreserved by vitrification in EFS solution. The mouse embryos were exposed to the EFS solution in one step at room temperature, kept in the EFS solution during different period for toxicity test, vitrified in liquid nitrogen and thawed rapidly. After the mouse morulae embryos were exposed to EFS solution for 2 and 5 ruin. at room temperature and then they were washed in 0.5 M sucrose solution and basal mediurn(D-PBS + 10% FCS), they were cultured to examined cryoprotectant toxicity induced injury during exposure, most of embryos developed to expanded blastocysts(100 and 90.0%). However, when the exposure time was extended to 10 and 20 min, these development rates dropped dramatically in 10 ruin. (75.0%) and 20 ruin. (4.5%), respectively. When the compacted morulae were vitrified in EFS solution after equilibration for 2 and 5 min, the embryos have developed to normal blastocyst following thawing, washing and culture processes was 89.3 and 89.6%. However, when the exposure time was expanded to 10 ruin, this survival rate dropped to 68.8%. When the blastocyst were vitrified in EFS solution after equilibration for 2, 5 and 10 minutes, the survival rate of embryos which developed to normal blastocyst following thawing and culture processing were 58.5, 46.7 and 22.4%, respectively. The optimal time of equilibration of mouse morula and blastocysts in EFS solution seemed o be 2 and 5 ruin.

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Solving Sangaku: A Traditional Solution to a Nineteenth Century Japanese Temple Problem

  • Hosking, Rosalie Joan
    • Journal for History of Mathematics
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    • v.30 no.2
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    • pp.53-69
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    • 2017
  • This paper demonstrates how a nineteenth century Japanese votive temple problem known as sangaku from Okayama prefecture can be solved using traditional mathematical methods of the Japanese Edo (1603-1868 CE). We compare a modern solution to a sangaku problem from Sacred Geometry: Japanese Temple Problems of Tony Rothman and Hidetoshi Fukagawa with a traditional solution of ${\bar{O}}hara$ Toshiaki (?-1828). Our investigation into the solution of ${\bar{O}}hara$ provides an example of traditional Edo period mathematics using the tenzan jutsu symbolic manipulation method, as well as producing new insights regarding the contextual nature of the rules of this technique.

Effect of Equilibration Time and Cell Stage on the Survival of IVF Bovine Embryos Cryopreserved by Vitrification (한우 체외수정란의 동결보존시 평형시간과 배 발달단계가 생존성에 미치는 영향)

  • 공일근;주영국;이은봉;김용권;박충생
    • Journal of Embryo Transfer
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    • v.9 no.1
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    • pp.7-14
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    • 1994
  • The present experiments on cryopreservation were designed to examine the effects of solution toxicity, equilibration time and cell stages on the post-thaw survival of bovine IVF embryos. The oocytes were matured in vitro(IVM) for 24 hrs. in TCM-199 supplemented with 35 $\mu$g /ml FSH, 10 $\mu$g /ml LH, 1 $\mu$g /ml estradiol-17$\beta$ and granulosa cells at 39$^{\circ}C$ under 5% $CO_2$ in air. They were fertilized in vitro(IVF) by epididymal spermatozoa treated with heparin for 24 hrs., and then the zygotes were co-cultured in vitro(IVC) with bovine oviductal epithelial cells for 7 to 9 days. The bovine IVF embryos were exposed to the EFS solution in one step at room temperature, kept in the EFS solution during different period for toxicity test, vitrified in liquid nitrogen, and thawed rapidly. 1. after the bovine blastocysts were exposed to EFS solution for 2 min. at room temperature and then they were washed in 0.5 M sucrose solution and TCM-199, they were cultured to examined cryoprotectant induced injury during exposure, Most of the embryos(95.0%) developed to reexpanded blastocoels. However, when the exposure time was extended to 5 and 10 min, these development rates dropped dramatically in 5 min. (69.5%) and 10 min. (47.4%), respectively, 2. When the bovine IVF embryos were vitrified in EFS solution after the equilibration for 1 and 2 min. exposure, The embryos to have reexpanded blastocoels following thawing, washing and culture processes were found to he 82.6 and 73.9%, respectively. However, when the exposure time was extended to 3 min, this survival rate dropped to 18.2%. The optimal time for equilibration of bovine IVF blastocysts in EFS solution seemed to he 1~2 min. 3. When the bovine IVF embryos were equilibrated for 1 min. the significantly (P<0. 05) higher post-thaw survival rates were obtained from the embryos of blastocyst stage(81.3%) than morulae stage(5. 1%). The optimal cell stage for viterification with EFS solution proven to he blastocyst stage in bovine IVF embryos. 4. The number of blastomeres of blastocyst stage was examined with nuclear staining with Hoechst 33342 during 7 to 9 days post-insemination. The cell counts of frozen bovine IVF embryos were found significantly(P$\geq$7.5 and those of the fresh embryos 76.6$\geq$7. 1, which were cultured in the sarne period and conditions as frozen embryos.

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Effect of Oxygenation of Cardioplegic Solution on Electrical Stability and Postischemic Recovery of Cardiac Function after Ischemic Arrest in Isolated Rat Heart[ I ] (백서의 적출된 심장에서 심정지액의 산소화가 허혈성 심정지후 심기능 회복에 미치는 영향[I])

  • 윤재도
    • Journal of Chest Surgery
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    • v.25 no.2
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    • pp.125-130
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    • 1992
  • To evaluate the effect of oxygenation[95% O2+5% CO2] of St. Thomas Hospital No.2 cardioplegic solution[Plegisol], 20 isolated perfused rat hearts were studied under hyp-othermic[20oC] ischemic arrest for 2 hours with infusion of cardioplegic solution every 30 minutes throughout the ischemic period. Ten isolated hearts were studied with the oxygenated cardioplegic solution and 10 another isolated hearts with the nonoxygenated one. Mean oxygen tensions of the nonoxygenated and oxygenated cardioplegic solutions were 150mmHg and 470mmHg, respectively. Two in 10 hearts infused with the nonaxygenated cardioplegic solution were not recovered from nonworking heart due to persistent ventricular fibrillation. In comparing hem-odynamic parameters between both groups, the mean postischemic recovery[expressed as a percentage of its preischemic control value] was significantly greater with the oxygenated solution[in 10 recovered hearts] than the nonoxygenated solution[in 8 recovered hearts] [95.9$\pm$1.8% compared with 88.5$\pm$2.9% in peak aortic pressure, p<0.05, 75.7$\pm$5.2% compared with 43.5$\pm$6.5% in aortic flow, p<0.01, 75.5$\pm$4.6% compared with 54.1$\pm$5.6% in cardiac output, p<0.01, 78.3$\pm$4.6% compared with 60.3$\pm$4.6% compared with 60.3$\pm$6.2% in stroke volume, p<0.05, and 80.4$\pm$5.3% compared with 58.6$\pm$7.0% in dP/dT, p<0.05]. It is concluded that oxygenation of St. Thomas Hospital No.2 cardioplegic solution improves cardiac electrical stability and postischemic hemodynamic recovery after ischemic arrest in the isolated perfused rat heart.

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Evaluation of Short-Term CO2 Passive Sampler for Monitoring Atmospheric CO2 Levels

  • Yim, Bongbeen;Sim, Yoon-Ah;Kim, Sun-Tae
    • Journal of Climate Change Research
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    • v.7 no.1
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    • pp.1-8
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    • 2016
  • In this study, we investigated the applicability of a short-term carbon dioxide ($CO_2$) passive sampler using turbidity change in a solution containing barium hydroxide ($Ba(OH)_2$). The mass of $CO_2$ introduced into the $Ba(OH)_2$ aqueous solution was strongly correlated ($r^2=0.9565$) to the change in turbidity caused by its reaction with the solution. The sampling rates calculated for 1 h and 24 h were $42.4{\pm}5.4mL\;min^{-1}$ and $2.3{\pm}0.3mL\;min^{-1}$, respectively. Both unexposed (blank) and exposed samplers remained stable during the storage period of at least two weeks. The detection limits of the passive sampler for $CO_2$ were 81.5 ppm for 1 h and 61.5 ppm for 24 h. Based on the results, the passive sampler using the change of turbidity in the $Ba(OH)_2$ aqueous solution appears to be a suitable tool for measuring short-term atmospheric concentrations of $CO_2$.

The Stability of Citrate-capped Silver Nanoparticles in Isotonic Glycerol Solution for Intravenous Injection (글리세롤을 이용한 구연산캡핑 은나노입자의 정맥주사용 현탁액 조제 및 안정성)

  • Lee, Yeon-Jin;Park, Kwang-Sik
    • YAKHAK HOEJI
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    • v.56 no.2
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    • pp.74-79
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    • 2012
  • Citrate-capped silver nanoparticles (AgNPs) are widely used in industry, consumer products and medical appliances. However, information on the toxicity, environmental fate and toxicokinetics are not enough. In this study, stability of citrate-capped AgNPs was investigated using different types of isotonic solution, which is important in the toxicokinetic study by the exposure route of intravenous injection. Size, morphology, zeta potential and ion formation were investigated in isotonic solutions for the physico-chemical characterization of AgNPs. Aggregation and precipitation of AgNPs were observed in saline or phosphate-buffered saline while they were stable without precipitation in 2% glycerol of isotonic solution. The average size of AgNPs in 2% glycerol was 6~10 nm, which was almost same as that in water-based suspension of AgNPs. Zeta potential was ranged from -30 mV to -60 mV, which was in the range of original stock AgNPs. The stability was maintained during the whole experimental period of 48 hours. Furthermore, the stability was not changed in different temperature (10~36$^{\circ}C$) and at different concentrations (10~1,000 ppm). The osmolarity of the AgNPs suspension was $299{\pm}1$ mOsm/kg which was in isotonic range. These data suggest that AgNPs in 2% glycerol solution can be used for the preparations of intravenous injection for toxicokinetic study without undesired disturbance of blood isotonicity.

A STUDY ON THE STAINING TENDENCY OF ETHETIC RESTORATIVE MATERIALS (심미성 수복재료의 착생경향에 관한 연구)

  • Shin, Heung-Soo;Hwang, Ho-Keel;Cho, Young-Gon
    • Restorative Dentistry and Endodontics
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    • v.20 no.1
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    • pp.372-383
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    • 1995
  • The staining tendency of esthetic restorative material was very important factor for the people who are great concern about the esthetics. Most external stains were superficial and adjustable by routine prophylactic procedure. But some of these stains were remained under superficial stain. Some of these stains were accumulative on external tooth surface and it's removal alter the anatomic contour of restoration. The purpose of this study was to evaluate and compare the staining tendency of esthetic restorative materials to staining solution. In this study two glass-ionomer cements (Fuji II Glass-Ionomer Cement and Fuji II LC Glass-Ionomer Cement) and three composite resins (Sil$\ddot{u}$x Plus, APH and P-50) were evaluated and compared. Total 8 disc-shaped specimens of each material (17mm diameter, Imm thick) were immersed in coffee staining solution. These specimens were divided into one control and 3 experimental groups according to the immersion period as follows : Control: immersed in distilled water during each testing period Group 1 : immersed in staining solution for 6 hours Group 2 : immersed in staining solution for 24 hours Group 3 : immersed in staining solution for 72 hours Staining tendency was evaluated by total color difference(${\Delta}E^*$) of specimen before and after staining by spectorcolorimeteric readings (ColorQUEST Spectrophotometer, U.SA.). The results were as follows : 1. The total color differences of each testing materials were increased with time. 2. Among the experimental groups, the Fuji II Glass Ionomer Cement showed the highest total color difference(6.803) and the Silux Plus showed the lowest total color difference(1.637). 3. In comparison of glass ionomer cements, the total color difference of chemical cured glass ionomer cements(6.803) were higher than light cured glass ionomer cements(3.891) (P<0.01). 4. In comparison of composite resins, the P-50 showed the highest total color difference and the Silux Plus showed the lowest total color difference, but there was not significant difference among composite resins(P>0.05).

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A Case Report of Korean Medicine Treatment for A Patient with Variant Angina and Asthma Symptoms (천식 증상을 가진 변형 협심증 환자에 대한 한방치료 증례보고)

  • Kim, Min-joo;Kwo, Tae-ha
    • The Journal of Internal Korean Medicine
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    • v.43 no.5
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    • pp.864-873
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    • 2022
  • Objective: The purpose of this case study was to report the symptom improvement effect of integrative Korean medicine treatment based on Pyongsim Solution: Cheonwangbosim-dan in a patient with variant angina and asthma symptoms. Methods: This 68-year-old male patient was treated with Pyongsim Solution, Gamihyangsayukgunja-tang, Gwakhyangjunggi-san, acupuncture, pharmacopuncture, and cupping therapy for 24 days. The European Quality of Life-5 Dimensions-5 Levels profile, Numerical Rating Scale score, and pulse rate per minute were measured on admission, at two weeks of hospitalization, and upon discharge to assess the clinical outcomes. Results: After treatment, the "mobility" dimension profile of the European Quality of Life-5 Dimensions-5 Levels changed from 1 to 1, "self-care" changed from 1 to 1, "usual activity" changed from 3 to 2, "pain/discomfort" changed from 4 to 3, and "anxiety/depression" changed from 3 to 2. The Numerical Rating Scale score for chest pain decreased from 7 to 5, chest tightness decreased from 6 to 4, sleep disturbance decreased from 6 to 3, polydipsia decreased from 5 to 3, and stomach discomfort decreased from 5 to 3. All the profiles of these five dimensions were unchanged for 11 days in the period between the two weeks of hospitalization and discharge. There were also no changes in the profiles of either "mobility" or "self-care" throughout the entire 24-day hospitalization period. Conclusion: This case report shows that integrative Korean medicine treatment based on Pyongsim Solution can improve the symptoms of patients with variant angina and mild intermittent asthma, suggesting that Pyongsim Solution could be an important herbal medication for treatment.