• Title/Summary/Keyword: 2D material

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Comparison of Inflammatory Response and Myocardial injury Between Normoxic and Hyperoxic Condition during Cardiopulmonary Bypass (체외순환 시 정상 산소분압과 고 산소분압의 염증반응 및 심근손상에 관한 비교연구)

  • 김기봉;최석철;최국렬;정석목;최강주;김양원;김병훈;이양행;조광현
    • Journal of Chest Surgery
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    • v.34 no.7
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    • pp.524-533
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    • 2001
  • Background: Hyperoxemic cardiopulmonary bypass (CPB) has been recognized as a safe technique and is widely used in cardiac surgery. However, hyperoxemic CPB may produce higher toxic oxygen species and cause more severe oxidative stress and ischemia/reperfusion injury than normoxemic CPB. This study was undertaken to compare inflammatory responses and myocardial injury between normoxemic and hyperoxemic CPB and to examine the beneficial effect of normoxemic CPB. Material and method: Thirty adult patients scheduled for elective cardiac surgery were randomly divided into normoxic group (n=15), who received normoxemic CPB (about Pa $O_{2}$ 120 mmHg), and hyperoxic group (n=15), who received hyperoxemic CPB (about Pa $O_{2}$ 400 mmHg). Myeloperoxidase (MPO), malondialdehyde (MDA), adenosine monophosphate (AMP), and troponin-T (TnT) concentrations in coronary sinus blood were determined at pre- and post-CPB. Total leukocyte and neutrophil counts in arterial blood were measured at the before, during, and after CPB. Lactate concentration in mixed venous blood was analyzed during CPB, and cardiac index (Cl) and pulmonary vascular

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Stress distribution in bone surrounding maxillary molar implants under different crown-to-fixture ratio: A 3D FEM analysis (치관/고정체 비에 따른 상악 구치부 임플란트 주변골의 응력 분포에 대한 3차원 유한요소법적 분석)

  • Park, Jong-Chan;Shin, Sang-Wan;Kwon, Kung-Rock
    • The Journal of Korean Academy of Prosthodontics
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    • v.46 no.5
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    • pp.479-489
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    • 2008
  • Statement of the problem: Under anatomical limitations on maxillary posterior region, a poor crown-to root ratio acting on dental implants can result in undesirable stress in surrounding bone, which in turn can cause bone defects and eventual failure of implants. Purpose: The purpose is to compare stress distribution due to different crown-root ratio and effect of splinting between natural teeth and implants in maxillary molar area under different loads. Material and methods: Analysis of stress arising supporting bone of the natural teeth and the implant was made with 3-dimensional finite element method. The model simulated naturel teeth was made with 2nd premolar and 1st molar in the maxillary molar region (Model T). The model simulated implants placed on same positions with two parallel implants of Straumann Dental Implant cemented abutment (Model I). Each model was designed in different crown-root ratio (0.7:1, 1:1, 1.25:1) and set cement type gold crown to make it non-splinted or splinted. After that, 300 N force was loaded to each model in five ways (Load 1: middle of occlusal table, Load 2: middle of buccal cusp, Load 3: middle of lingual cusp, Load 4: horizontal load to buccal cusp of anterior abutment only, Load 5: horizontal load to middle of buccal cusp of each abutment), and stress distribution was analyzed. Results and conclusion: On all occasions, stress was concentrated at the cervical region of the implant. Under load 1, 2 and 3, stress was not increased even when crown-root ratio increases, but under load 4 and 5, when crown-root ratio increases, stress also increased. There was difference in stress values between natural teeth and implants when crown-root ratio gradually increases; In case of natural teeth, splinting decreased stress under vertical and horizontal loads. In case of implants, splinting decreased stress under vertical loads 1,2 and 3, but increased maximal stress under loads 2 and 3. Under horizontal loads, splinting decreased stress, however the effect of splinting decreased under load 5 than load 4. Furthermore, the stress was increased, when crown-root ratio is 1.25:1. Clinical implications: This limited finite element study suggests that the stress on supporting bone may be increased under non-axial loads and poor crown-root ratio. Under poor crown-root ratio, excessive stress was generated at the cervical region of the implant, and decreased splinting effect for stress distribution, which can be related to clinical failure.

Antioxidant activity of premature mandarin vinegar according to harvest period and raw material conditions (수확시기 및 원료 조건에 따른 풋귤 식초의 항산화 활성)

  • Park, Boyeon;Choi, Jae Won;Kim, Sung Hyun;Yun, Ye-Rang;Lee, Young ran;Lee, Young mi;Jung, Ji-Hye
    • Korean Journal of Food Science and Technology
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    • v.52 no.4
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    • pp.333-341
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    • 2020
  • This study aimed at comparing the antioxidant activity of premature mandarin (PM) vinegars by varying harvest periods (July, August, and September) and raw material conditions (PM fruit, PMF; PM fruit with 10% dried Citri Unshius Pericarpium Immaturus (CUPI), PMF-D, and PM fruit with 10% roasted CUPI, PMF-R). We found that the PM harvested in July exhibited the highest phenol content. Meanwhile, the July and August harvests showed stronger DPPH radical scavenging and reducing power. The phenol content of PMF-R vinegar was 0.62±0.02 ㎍ GAE/mL, more than two times higher than that of PMF vinegar. The DPPH radical scavenging capacity and reducing power were the highest in the PMF-R vinegar, at 4.71±0.07 and 7.47±0.28 nL/mL, respectively. Therefore, it could be expected that PM vinegar prepared by adding roasted CUPI and harvested in July would exhibit high antioxidant activity and could be used as functional vinegar.

MHC Class II Allele Association in Korean Children With IgA Nephropathy and its Role as a Prognostic Factor (한국인 IgA 신병증 환아에서 MHC Class II유전자형과 예후와의 관계 분석)

  • Kim Pyung Kil;Yook Jinwon;Kim Ji Hong;Jang Yoon Soo;Shin Jeon-Soo;Choi In-Hong
    • Childhood Kidney Diseases
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    • v.4 no.1
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    • pp.33-39
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    • 2000
  • Purpose: Our study was designed to investigate the association of MHC Class II (DR, DQ) allele with IgA nephropathy and its significance as a prognostic factor for progression to ESRD Material and Methods: 69 children with IgA nephropathy with normal renal function(serum creatinine $\leq$ 1.5mg/dL) was classified as group A and 70 patients who received renal transplantation due to IgA nephropathy were selected as group B. The HLA-DQB1 and HLA-DRB1 alleles were studied by polymerase chain reaction using sequence specific primers. We have compared the difference in alleles between these two groups and with normal control and also examined any possible effect of the MHC class II genes on the histopathological severity and prognosis of IgAN. Results: Mean age was $8.8{\pm}2.9$ years in group A and $35.0{\pm}15.5$ years in group B. Male to female ratio was 2.8:1 in group A and 2.5:1 in group B. There was a significantly higher frequency of HLA-$DQB1^*03\;and\;DQB1^*05$ in Group B. The frequency of HLA-$DQB1^*0302\;and\;^*05031$ allele had increasing tendency in Group B(P<0.05). HLA-$DRB1^*03\;and\;^*05$ were more common in Group B(P<0.05). HLA-$DRB1^*04$ allele was the most common DR alleles in both group, but there was no statistical significance. There were no significant correlation with MHC class 13 genes on the hjstopathological severity in Group A. Conclusion: In conclusion, $HLA-DQB1^*0302\;and\;HLA-DQB1^*05031 $ allele seemed to be more common in transplanted patients compared to group with normal renal function suggesting that this allele is associated with poor prognosis in IgAN. However larger studies and follow up are required to confirm this due to uncharacterized heterogeneity in etiopathogenesis of IgA nephropathy and possibly one or more than one gene may exert influence in determining susceptibility to the diseases.

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A Study on the Moisturizing Effect and Preparation of Liquid Crystal Structures Using Sucrose Distearate Emulsifier (슈크로오스디스테아레이트를 사용한 액정구조의 생성과 보습효과에 관한 연구)

  • Kwak, Myeong-Heon;Kim, In-Young;Lee, Hwan-Myung;Park, Joo-Hoon
    • Journal of the Korean Applied Science and Technology
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    • v.33 no.1
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    • pp.1-12
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    • 2016
  • This study is to make the liquid crystalline structure using sucrose distearate (Sucro-DS) emulsifier to create the hydrophilic type oil-in-water (O/W) emulsion, the droplets of the emulsion having a structure of a multi-lamellar structure. We have studied the physicochemical properties of Sucro-DS using those techniques. And it has been studied in the emulsion performance. In order to form the liquid crystalline structure applying 3 wt% of Sucro-DS, 5 wt% of glycerin, 5 wt% of squalane, 5 wt% of capric/caprylic triglyceride, 3wt% of cetostearyl alcohol, 1wt% of glyceryl mono-stearate, 78 wt% of pure water in mixture having the lamellar structure of stable multi-layer system was found to formed. By applying them, they were described how to create an unstable active material encapsulated cream. Further, the moisturizing cream was studied using this technique. It reported the results to the skin improvement effect by the human clinical trials. The pH range to produce a stable liquid crystal phase using a Sucro-DS was maintained in 5.2~7.5. In order to increase the stability of the liquid crystal, it was when behenyl alcohol containing 3 wt%, the hardness at this time was 13 kg/mm,min. Viscosity of the same amount was 25,000mPas/min. After a test for the effects of the emulsions, the concentration of 6 wt% Sucro-DS is that was appropriate, the particle size of the liquid crystal was 4~6mm. It was observed through a microscope analysis, reliability of the liquid crystal changes for 3 months was found to get stable at each $4^{\circ}C$, $25^{\circ}C$ and $45^{\circ}C$. In clinical trial test, before applying a moisturizing effect it was $13.4{\pm}7%$. Moisturizing cream liquid crystal was not formed in $14.5{\pm}5%$. Therefore, applying than ever before could see the moisture about 8.2% was improved. On the other hand, it was the moisturizing effect of the liquid cream is $19.2{\pm}7%$. The results showed that 43.3% improvement than that previously used. Applications fields, Sucro-DS emulsifier used liquid cream, lotion, eye cream and a variety of formulations can be developed, as well as the cosmetics industry is expected to be wide fields in the application of the external preparation for skin emulsion technology in the pharmaceutical industry and pharmaceutical industry.

Ischemic Preconditioning and Its Relation to Glycogen Depletion (허혈성 전처치와 당원 결핍과의 관계)

  • 장대영;김대중;원경준;조대윤;손동섭;양기민;라봉진;김호덕
    • Journal of Chest Surgery
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    • v.33 no.7
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    • pp.531-540
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    • 2000
  • Baclgrpimd; Recent studies have suggested that the cardioprotective effect of ischemic preconditioning(IP) is closely related to glycogen depletion and attenuation of intracellular acidosis. In the present study, the authors tested this hypothesis by perfusion isolated rabbit hearts with glucose(G) is closely related to glycogen depletion and attenuation of intracellular acidosis. In the present study, the authors tested this hypothesis by perfusion isolated rabbit hearts with glucose(G)-free perfusate. Material and Method; Hearts isolated from New Zealand white rabbits(1.5~2.0 kg body weight) were perfused with Tyrode solution by Langendorff technique. After stabilization of baseline hemodynamics, the hearts were subjected to 45 min global ischemia followed by 120 min reperfusion with IP(IP group, n=13) or without IP(ischemic control group, n=10). IP was induced by single episode of 5 min global ischemia and 10 min reperfusion. In the G-free preconditioned group(n=12), G depletion was induced by perfusionwith G-free Tyrode solution for 5 min and then perfused with G-containing Tyrode solution for 10 min; and 45 min ischemia and 120 min reperfusion. Left ventricular functionincluding developed pressure(LVDP), dP/dt, heart rate, left ventricular end-distolic pressure(LVEDP) and coronary flow (CF) were measured. Myocardial cytosolic and membrane PKC activities were measured by 32P-${\gamma}$-ATP incorporation into PKC-specific peptide and PKC isozymes were analyzed by Western blot with monoclonal antibodies. Infarct size was determined by staining with TTC(tetrazolium salt) and planimetry. Data were analyzed by one-way analysis of variance (ANOVA) and Turkey's post-hoc test. Result ; In comparison with the ischemic control group, IP significantly enhanced functional recovery of the left ventricle; in contrast, functional significantly enhanced functional recovery of the left ventricle; in contrast, functional recovery were not significantly different between the G-free preconditioned and the ischemic control groups. However, the infarct size was significantly reduced by IP or G-free preconditioning(39$\pm$2.7% in the ischemic control, 19$\pm$1.2% in the IP, and 15$\pm$3.9% in the G-free preconditioned, p<0.05). Membrane PKC activities were increased significantly after IP (119%), IP and 45 min ischemia(145%), G-free [recpmdotopmomg (150%), and G-free preconditioning and 45 min ischemia(127%); expression of membrane PKC isozymes, $\alpha$ and $\varepsilon$, tended to be increased after IP or G-free preconditioning. Conclusion; These results suggest that in isolated Langendorff-perfused rabbit heart model, G-free preconditioning (induced by single episode of 5 min G depletion and 10 min repletion) colud not improve post-ischemic contractile dysfunction(after 45-minute global ischemia); however, it has an infarct size-limiting effect.

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Spectrophotometric analysis of the influence to shade of zirconia core on the color of ceramic (지르코니아 코아의 색조부여가 전부도재관의 색조에 미치는 영향에 대한 분광측색분석)

  • Baek, Ki-Hyun;Woo, Yi-Hyung;Kwon, Kung-Rock;Kim, Hyeong-Seob
    • The Journal of Korean Academy of Prosthodontics
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    • v.46 no.4
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    • pp.409-419
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    • 2008
  • Statement of problem: At all times people have tried to fabricate tooth restorations using tooth colored materials. Recently, demands for esthetics, even in restorations requiring strength, has brought a revolution to dentistry and increased use of zirconia. The basic color of zirconia is white to ivory. The color can be partially adapted by veneering it with ceramic materials. However, it would be better if the substructure could already be adapted to the basic color shade of neighboring teeth. By adaptation to the basic shade, it can help to reduce the necessary layer thickness of the veneer ceramic to achieve the desired color. Purpose: The purpose of this study was to spectrophotometrically evaluate the influence of shading of zirconia core on the final shade of all-ceramic restorations using the CIE $L^{*}a^{*}b^{*}$ system. Material and methods: Core specimens (n = 20 per group) of Lava Frame Zirconia, KaVo Everest Zirconia, Digident CAD/CAM Zirconia were fabricated at 20 mm in diameter and 0.5 mm in thickness. Halves of each groups were shaded in A3 color. These core specimens were veneered with A3 porcelain of the recommended manufacturer at thickness of 0.5 mm. CIE $L^{*}a^{*}b^{*}$ coordinates were recorded for each specimen with a spectrophotometer (Model CM-2600d, Minolta, Japan) at 0.5 mm, 0.4 mm, 0.3 mm in thickness. Color differences were calculated using the equation ${\Delta}E^{*}=[({\Delta}L^{*})2+({\Delta}a^{*})2+({\Delta}b^{*})2]1/2$. Results: 1. In the case where porcelain layer has a thickness of 0.5 mm, Lava Frame Zirconia and KaVo Everest group did not show clinically perceived color difference, however Digident CAD/CAM Zirconia group showed clinically perceived color difference according to shade allowed on core. 2. When the thickness of porcelain layer decreased from 0.5 mm to 0.4 mm, Lava Frame Zirconia and KaVo Everest group did not show clinically perceived color difference, on the other hand Digident CAD/CAM Zirconia group showed clinically perceived color difference according to shade allowed on core. 3. When the thickness of porcelain layer decreased from 0.5 mm to 0.3 mm, clinically perceived color differences were observed from all three groups. Conclusions: Ziroconia system, which is possible to allow shade on core, are thought to be much more favorable to reproduce natural shade compared to systems that is impossible to give shade. Therefore, clinicians ought to choose adequate system for certain clinical situation by considering above specific character.

Growth and Survival of Rhizobium meliloti M14 on Korean Peat Carrier (Rhizobium meliloti M14의 니탄배양(泥炭培養)에 관(關)한 연구)

  • Choi, Woo Young;Kim, Moon Kyu
    • Korean Journal of Agricultural Science
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    • v.8 no.2
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    • pp.238-243
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    • 1981
  • This experiment was carried out to study the availability of Korean peat as a main carrier material of rhizobial inoculant, using the alfalfa strain Rhizobium meliloti M 14 which was isolated in the previous report. Modification of powdered peat with calcium carbonate and other materials was studied; inoculation of the peat with culture broth, maturation of the mixture under different conditions, and survival of the strain in the peat culture was examined. The results obtained were as follows. 1. Peat produced in Pyongtak was highly acidic, pH 3.8, and addition of calcium carbonate by 14% was required for pH adjustment to 6.4. However the amount of calcium carbonate could be reduced by 4 to 8% when carbon or charcoal was mixed with the peat. 2. Viable number of the strain reached to $7-9{\times}10^9cells/g$ after 3 days, when inoculated with the culture broth of early stationary growth phase and matured in unsteriled peat of open trays; and the number in steriled peat was $1.1-6.2{\times}10^{10}cells/g$ after 5 days, when matured in closed bottles. 3. Survival of the strain was affected markedly by storage temperature, and positive effect of D-sorbitol on the viability was recognized at elevated temperatures, when added as an additional carbon source and moistening agent. Glycerol, sorbitol, or sodium lactate was utilized by the strain as a sole source of carbon, and the decimal reduction time of viable number in the peat culture was was found to be 8 to 9 weeks at $25^{\circ}C$ when these agents were added by 0.5%.

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Current Status of Korean Ginseng Research (한국인삼론(韓國人蔘論))

  • Han, Byung-Hoon
    • Korean Journal of Pharmacognosy
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    • v.3 no.3
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    • pp.151-160
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    • 1972
  • Recent achievements of scientific research on the pharmacologic activities and the chemical problems of dammalene glycosides, which are considered to be effective principles of Korean ginseng, are reviewed and analyzed in view of structure-activity relationship. 1) S. Shibata and his co-workers detected 12 glycoside spots of dammalene series on the two dimensional T.L.C. of total glycoside fraction from Japanese ginseng, and designated them Ginsenoside Rx(x=a, b, c, g, h, etc.) in the order of increasing Rf-value. The aglycones of those glycosides were characterized to be protopanaxadiol for the Ginsenoside $Rx(x=a,\;b_{1},\;b_{2},\;c,\;d,\;e,\;f)$ and protopanaxatriol for the Ginsenoside $Rx(x=g_{1},\;g_{2},\;g_{3},\;h_{1}\;'h_{2})$. Using Korean ginseng as the material for our study, the author and his coworkers isolated a new dammalene glycoside(Panax Saponin C), which comes under the category of protopanaxadiol glycosides based on the classification of S. Shibata et al., and characterized this saponin to be the glycoside of protopanaxatriol series. Furthermore, Panax Saponin C dissociated into $two\;components(C_{1}\;and\;C_{2}-acetate)$ by acetylation, both of which returned to original Panax Saponin C by deacetylation. Based on this result, more than 13 glycoside components of dammalene series will be expected in the Korean ginseng. 2) The structures of protopanaxadiol and protopanaxatriol, the genuine aglycones of dammalene glycosides, are fully established to be structural analogues by S. Shibata and his co-workers, therefore antagonistic and/or analogical activities will be expected for the pharmacologic activities of these glycoside series of structural analogues. K. Takaki and his co-workers found central nervous system (CNS) stimmulant activity from the glycosides of protopanaxatriol series and CNS-depressant activity from the glycosides of protopanaxadiol series. On the other hand, the author and his co-workers found stimmulating activity on the protein synthesis from both the series of dammalene glycosides with delayed and long-lasting characteristics. This delayed and long-lasting characteristics were also observed in the anti-inflammatory activity of glycosides of protopanaxatriol series on their time course tendency. For the convenience's sake of argument, pluralistic pharmacologic activities of dammalene glycosides, which were observed by many workers at various pharmacologic site, may be classified into two main categories; one is pan-cellular activity and the other is organ specific activity to the certain tissue which is a mass of cells differentiated to a certain direction for their special functions in the body. Based on the data of K. Takaki and those of the authors, following assumption will be probable; Pharmacologic activities of both series of glycosides of protopanaxadiol and protopanaxatriol aglycones may be antagonistic on their tissue-specific activities and analogic on their pan-cellular activities. Therefore, the mixture of these two series of glycosides in an appropriate ratio, as the case of total extract of Korean ginseng, will be probably beneficial to the host by increasing the synthesis of some functional proteins, due to the additive action of pan-cellular activity, and with the disappearance of any significant behavioral symptoms due to the antagonism of tissue specific activity. This fact will probably be the main reason why classical trials of pharmacologists failed in re-discovering the efficacy of Korean ginseng with their behavioral test. 3) The author and his co-workers achieved the synthesis of $C^{14}-labelled\;Panax\;Saponin\;A\;on\;C_{25}-C_{27}\;position\;of\;aglycone$ in the interest of tracer studies in vivo. The method will be applicable to other dammalene glycosides regardless of their chemical structure. 4) The author and his co-workers converted chemically betulafolienetriol, a triterpene component of Betula platyphylla, to the protopanaxadiol, one of genuine aglycone of dammalene glycosides.

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Determination of Electron Spin Relaxation Time of the Gadolinium-Chealted MRI Contrast Agents by Using an X-band EPR Technique (EPR을 통한 상자성 자기공명 조영제의 전자스핀 이완시간의 결정)

  • Sung-wook Hong;Yongmin Chang;Moon-jung Hwang;Il-su Rhee;Duk-Sik Kang
    • Investigative Magnetic Resonance Imaging
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    • v.4 no.1
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    • pp.27-33
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    • 2000
  • Purpose: To determine the electronic spin relaxation times, $T_{le}$, of three commercially available Gd-chelated MR contrast agents, Gd-DTPA, Gd-DTPA-BMA and Gd-DOTA, using Electron Paramagnetic Resonance(EPR) technique. Material and Methods: The paramagnetic MR contrast agents, Gd-DTFA(Magnevist) , Gd-DTFA-BMA(OMNISCAN) and Gd-DOTA(Dotarem), were used for this study, The EPR spectra of these contrast agents, which were prepared 2:1 methanol/water solution, were obtained at low temperatures, from $-160^{\circ}C~20^{\circ}C$. The glassy-state EPR spectra for these contrast agents were then fitted by the simulation spectra generated with different zero-field splitting (ZFS) parameters by a computer simulation program 'GEN', which generates the EPR powder spectrum using a given ZFS in $3{\times}3$ tensor. Finally, the spin relaxation times of the contrast agents were then determined from the $T_{2e}$, D, and E values of the best simulation spectra using the McLachlan's theory of average relaxation rate. Results: The electronic transverse spin relaxation times, $T_{2e}'s$, of Gd-DTPA, Gd-DTPA-BMA and Gd-DOTA were 0.113ns, 0.147ns and 1.81ns respectively. The g-values were 1.9737, 1.9735 and 1.9830 and the electronic spin relaxation times, $T_{1e}'s$, were 18.70ns, 33.40ns and $1.66{\mu}s$, respectively. Conclusion: The results of these studies reconfirm that the paramagnetic MR contrast agents with larger ZFS parameters should have shorter $T_{1e}'s$. Among three contrast agents used for this study, Gd-DOTA chelated with cyclic ligand structure shows better electronic property then the others with linear structure. Thus, it is concluded that the exact determination of ZFS parameters is the important factor in evaluating relaxation enhancement effect of the agents and in developing new contrast agents.

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