• Title/Summary/Keyword: Injection process

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Pharmacokinetic Modeling of Reversible Interconversion between Prednisolone and Prednisone (가역적상호대사과정 모델을 이용한 Prednisolone과 Prednisone의 약동학적 분석)

  • Shin, Jae-Gook;Yoon, Young-Ran;Cha, In-June;Jang, In-Jin;Lee, Kyung-Hoon;Shin, Sang-Goo
    • The Korean Journal of Pharmacology
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    • v.32 no.2
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    • pp.269-281
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    • 1996
  • Pharmacokinetics of prednisolone and prednisone undergoing reversible interconversion were analyzed from the model including this metabolic process. Blood samples were drawn serially upto 12 hours after I,V. bolus injection of 1 mg/kg prednisolone sodium phosphate and prednisone into 8 dogs as a crossover manner. Plasma concentrations of those two steroids were simultaneously measured with the method of HPLC. After injection, plasma concentrations of administered prednisolone and prednisone were declined with a biexponential pattern and their metabolic partner was rapidly formed. Plasma concentrations of those metaboite were decayed in parallel with their parent steroids throught the elimination phase. Apparent clearances of prednisolone and prednisone were $11.1{\pm}2.0\;ml/min/kg$ and $45.9{\pm}6.4\;ml/min/kg$, and they were underestimated by 29.4% and 33.6% compared to their real clearances$(15.7{\pm}4.4\;and\;69.2{\pm}17.7\;ml/min/kg)$ estimated using reversible interconversion model. Apparent volume of distribution of prednisolone$(1.32{\pm}0.43\;L/kg)$ and prednisone$(4.81{\pm}2.75\;L/kg)$ were overestimated by 53.5 and 52.7% and were compared to the real volumes $(0.86{\pm}0.30\;and\;3.15{\pm}2.13\;L/kg)$. Mean residence time of prednisolone$(2.0{\pm}0.61\;h)$ and prednisone$(1.74{\pm}0.74\;h)$ were much longer than the real sojourn time$(0.93{\pm}0.26\;and\;0.88{\pm}0.54\;h)$. Essential clearances In the reversible interconversion were greater as following orders: $Cl_{21}$(44.3 ml/min/kg) > $Cl_{20}$(24.2 ml/min/kg) > $Cl_{12}$ (7.9 ml/min/kg) > $Cl_{10}$(7.8 ml/min/kg). Estimated mean values of RF, EE, $%X^1_{ss}$ and $RHO^2_1$ were $0.31{\pm}0.10$, $1.49{\pm}0.23$, $69.3{\pm}16.7%$ and $0.65{\pm}0.10$, respectively. These results suggested that true pharmacokinetic parameters estimated from the model including reversible interconversion were significantly different from the apparent parameters estimated from the conventional mamillary model, and disposition of these two steroids seemed to be well explained by the model including reversible interconversion.

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Fabrication and transcription estimation of prismless LGP for cellular phone using E-Mold technology (전열가열방식을 이용한 휴대전화용 복합기능 도광판 제작 및 전사성 평가)

  • Kim, Young-Kyun;Chung, Jae-Youp;Kim, Dong-Hak
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.1
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    • pp.186-193
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    • 2009
  • In this paper, we adopted E-MOLD patent technology in order to fabricate Prismless LGP(Light Guide Panel) fur cellular phone and estimate the transcription of injection-molded parts. Then, we manufactured the Ni stamper fur Prismless LGP using MEMS process. And the stamper was installed in the movable heated core which is the key part of a patented mold. Using this mold, we manufactured injection-molded plastic LGP parts with different mold temperatures so that we investigate effect of the temperature on the transcription of the parts. The CAE analysis was also conducted in order to compare with the experimental results. The transcription of LGP parts with various mold temperature displayed $100^{\circ}C$(25.0nm), $140^{\circ}C$(48.4nm), $180^{\circ}C$(52.1nm) and when compared with stamper(521Inm), transcription was superior at $180^{\circ}C$. According to the CAE results, moldability was improved as mold temperature ($50^{\circ}C{\sim}180^{\circ}C$) increased, but when filling time($1{\sim}2sec$) increases, it decreased at $160^{\circ}C$. And transcription and moldability were improved markedly at glass transition temperature($140^{\circ}C$).

BIOLOGICAL EFFECT OF MAGNOLIA AND GINKGO BILOBA EXTRACT TO THE ANTIMICROBIAL, ANTIINFLAMMATORY AND CELLULAR ACTIVITY (후박 및 은행잎 추출물의 향균, 향염 및 세포활성도에 미치는 영향)

  • Chung, Chong-Pyuong;Ku, Young;Bae, Ki-Hwan
    • Journal of Periodontal and Implant Science
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    • v.25 no.3
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    • pp.478-486
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    • 1995
  • Periodontal therapy for treatment of periodontitis involves the elimination of bacterial plaque and elimination of the anatomic defects by regenerative procedure. The purpose of this study was to evaluate on the biological effect of magnolia and Ginkgo biloba extract to the antimicrobial, antiinflammatory and cellular activity. Antimicrobial assay was performed with the diffusion method of the extract by measuring of growth inhibitory zone of B. cereus from blood agar plate. Effect of the extract to cellular activity of gingival fibroblast were examined using MTT method and measured the result with optical density on 570nm by ELISA reader. Inhibitory effects of $PGE_2$ production from gingival fibroblast was performed with the addition of $IL-l{\beta}$ and the extract to the well and examined to the product of $PGE_2$ from cell by ELISA reader. In vivo anti-inflammatory effect was performed with injection examined with clinically and histologically for their extent of mecrosis and inflammation. Antimicrobial activity of Magnolia extract showed significantly higher activity than that of control. However, GBE did not showed significant activity to compare with control, and mixture of Magnolia and GBE extract showed significantly higher activity than that of control. The effect of cellular activity to gingival fibroblast showed no significant differences of between control and Magnolia extract. However, GBE showed significantly higher rate of cellular activity to compare with control and even to PDGF-BB, and also showed same degree of cellular activity even though mixed with Magnolia extract. The inhibitory effect of $PGE_2$ production showed significantly reduction of $PGE_2$ production to compare with control, but its inhibitory effect was not much strong to compare with Indomethacin. In vivo, antiinflammatory effect of Magnolia extract to P. gingivalis injection of Hamster buccal check showed significantly reduction of inflammatory cell infiltration and tissue necrosis, but GBE showed no effect on the inhibition of inflammatory process. These results suggested that Magnolia and GBE extract possessed different kind of biological activity and also can be compensated on their activity with each other for elimination of bacterial plaque and anatonical defect.

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Platelet Rich Plasma Injection: Evidence Based Analysis (혈소판 풍부 혈장 주사 요법: 근거 중심의 분석)

  • Oh, Joo Han;Chung, Seok Won
    • The Journal of Korean Orthopaedic Ultrasound Society
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    • v.4 no.2
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    • pp.111-122
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    • 2011
  • Platelet rich plasma (PRP) has been widely used nowadays for several common orthopaedic-related sports medicine conditions with the theoretical basis that PRP supplies numerous autologous growth factors from concentrated platelets needed to promote the healing process of injured tissue. Even though there are many basic sciences, animal studies and some clinical studies regarding PRP injections for musculoskeletal injuries which suggested good results, it is difficult to compare these various studies due to marked methodological differences such as PRP preparation method, the timing, volume and number of injection, and the outcome measurement tool. In addition, many studies have no control groups or a limited sample size, and there are few prospective randomized controlled trials assessing the efficacy of PRP injections. Therefore, well designed high-quality randomized studies are required to confirm the preliminary results until now and provide scientific evidence to support its use, and the paucity of scientific clinical evidence suggest that the administration of PRP on humans for musculoskeletal injuries should be performed with caution.

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Histopathological studies on the macrophage behavior in lymphomyeloid tissues of tilapia, Oreochromis niloticus (나일틸라피아의 임파조혈조직내 대식세포(大食細胞) 분포변화(分布變化)에 관한 병리조직학적(病理組織學的) 연구(硏究))

  • Lee, Nam-Sil;Kim, Jee-Young;Jeong, Hyun-Do;Huh, Min-Do
    • Journal of fish pathology
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    • v.8 no.2
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    • pp.135-148
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    • 1995
  • To elucidate the distributional pattern of macrophages within lymphomyeloid tissues according to the disease process, tilapias, teleostean fish, were intraperitoneally injected with live Edwardsiellatarda and its extracellular product(ECP) respectively. And then histopathological examination for the spleen and gead kidney were carried out for the individuals which had not any clinical signs. In the group injected with live E. tarda, macrophages were densely organized into MMC-like structures with showing some degree of recovery in histological arrangement. At the 2nd week, overall structures of the lymphomyeloid tissues became normal, accompanying the disappearance of most of macrophage groups. Also in case of ECP injection, quite similar findings were observed. Moreover, macrophage collections and hypertrophied ellipsoids were recognized at 1hour after the injection of ECP in head kidney and spleen, respectively. These results suggested that characteristic behaviors of macrophages in lymphomyeloid tissues would be used as important morphological criteria for early diagnosis of edwarsiellosis or possibly of other infectious diseases.

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Performance Characteristics of p-i-n Type Organic Thin-film Photovoltaic Cell with CuPc: $F_4$-TCNQ Hole Transport Layer (CuPc: $F_4$-TCNQ 정공 수송층이 도입된 P-i-n형 유기 박막 태양전지의 성능 특성 연구)

  • Park, So-Hyun;Kang, Hak-Su;Senthilkumar, Natarajan;Park, Dae-Won;Choe, Young-Son
    • Polymer(Korea)
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    • v.33 no.3
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    • pp.191-197
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    • 2009
  • We have investigated the effect of strong p-type organic semiconductor $F_4$-TCNQ-doped CuPc hole transport layer on the performance of p-i-n type bulk heterojunction photovoltaic device with ITO/PEDOT:PSS/CuPc: $F_4$-TCNQ(5 wt%)/CuPc:C60(blending ratio l:l)/C60/BCP/LiF/Al, architecture fabricated via vacuum deposition process, and have evaluated the J-V characteristics, short-circuit current ($J_{sc}$), open-circuit voltage($V_{oc}$), fill factor(FF), and power conversion efficiency(${\eta}_e$) of the device. By doping $F_4$-TCNQ into CuPc hole transport layer, increased absorption intensity in absorption spectra, uniform dispersion of organic molecules in the layer, surface uniformity of the layer, and enhanced injection currents improved the current photovoltaic device with power conversion efficiency(${\eta}_e$) of 0.16%, which is still low value compared to silicone solar cell indicating that many efforts should be made to improve organic photovoltaic devices.

A Study on the Nitrate Removal in Water by Chelating Bond of Calcium Alginate (Calcium Alginate의 킬레이트 결합을 이용한 수중의 질산성 질소 제거에 관한 연구)

  • Kim, Tae Kyeong;Song, Ju Young;Kim, Jong Hwa
    • Journal of the Korean Applied Science and Technology
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    • v.33 no.4
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    • pp.795-801
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    • 2016
  • This study is on the denitrification process using the sodium alginate and $CaCl_2$ as a flocculant. Removal techniques of nitrate nitrogen from waste water are reverse osmosis, ion exchange, electro dialysis and biological method etc. We tried to remove nitrate nitrogen with flocculation and sedimentation method in the present study. Calcium alginate is expected to form a chelate bond with nitrate nitrogen in the solution. So the effects of flocculantt component, flocculation reaction time, molar ratio of the flocculant, flocculant injection rate are studied to determine the best removal rate of nitrate nitrogen. In addition, we tried to determine the nitrate nitrogen removal mechanism by analyzing the structure and component ratio of the configuration after the agglutination precipitate by FE-SEM and EDS. As a result, the nitrate nitrogen removal mechanism is turned out to form calcium-nitro-alginate, and the best mole ratio of flocculating agent is 1 : 1, the injection rate of the flocculant was up to 2%, the removal rate of the nitrate nitrogen to be 56.7% in the synthetic wastewater.

A Study on Needle Stick Injuries in Health Professionals (의료인의 바늘자상 실태에 관한 연구)

  • 김영분
    • Journal of Korean Academy of Nursing
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    • v.26 no.3
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    • pp.605-622
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    • 1996
  • Needle stick injury, in which blood-borne pathogens including Human Immune-Deficiency virus and hepatitis B virus are transmitted, is one of the major occupational hazards that health professionals face everyday. In order to provide basic data for the development of educational programs for health professionals aimed at preventing and effectively managing needle stick injuries, a retrospective descriptive study was carried out .The subjects of the study were 630 health professionals, 499 nurses and 131 physicians, from two university hospitals in Seoul, Korea. Data on episodes of needle stick experiences over the past is months September 1994 through August 1995, were collected between September 1 and 7, 1995. A Questionaire developed by the researcher was used. The frequencies and the percentile score for episodes of needle stick injuries were calculated using the PC-SAS program. The differences and similarities in reference to the structure, career, and specialty variables were analysed by X$^2$-tests. Results are as follows : 1. Of the sample, 521(82.7%) reported a needle stick injury, 33.4% reported 3 or more episodes of needle stick injuries. 2. The needle stick injuries occured in the following processes : process of percutaneous venepuncture for intra-venous injection and infusion(55.3%), medical examination and treatment(48.9%), per-cutaneous venepuncture for blood sampling (46.3%) and intra-muscular injection(42.2%). 3. The study showed that needle stick injuries occured before(19%), during(25%), and after (56%) client treatment. The major causes of needle stick injuries were perceived to be hastiness(82.2%) and carelessness(48.3%). Of these injuries, 91.8% occured in emergency situations. 4. Follow of care for the injury consisted of : treating the injured site immediately using disinfectants(89.7%), reviewing the clinical records of the patient involved(84.2%), immunological investigation for the status of antibodies(11.1%) and self-medication of antibiotics (10.7%). Only 16.3% of the total episodes were founded to have been reported to the administrative unit. 5. The length of clinical experience of the nurses, clinical specialty and length of clinical experience in physicians were found to have influenced the episodes of needle stick injuries ; nurses with less than 1 year and with more than 6 years of clinical experiences had significantly lower levels (X$^2$=25.04, P=.00), surgeons had significantly higher levels (X$^2$=9.89, P=.02) compared to that of internists and interns, higher(X$^2$=4.54, P=.03)than residents.

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A Study of the Factors Affecting the Backward Transfer of BSA from AOT Reverse Micellar Solutions (AOT 역미셀 용액으로부터 BSA의 역추출에 영향을 미치는 인자들에 관한 연구)

  • 노선균;강춘형
    • KSBB Journal
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    • v.15 no.6
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    • pp.649-657
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    • 2000
  • The factors affecting the back-extraction efficiency of Bovine Serum Albumin (BSA, Mw. 65kDa, pl 4.9) solubilized in an AOT reverse micellar solution, prepared by the injection method, to an excess aqueous phase were investigated. In particular, the effects of pH, the types of salts, alcohols added as cosurfactants, and their concentrations in the aqueous phase were examined. Furthermore, by comparing the CD spectra of the back-extracted BSA and the feed BSA, the structural changes of BSA during the extraction process were determined. The addition of 1:1 salt such as KCl or NaCl to the aqueous phase resulted in almost a 100% extraction to the aqueous phase at a pH higher than its isoelectric point pl. This high efficiency of back-extraction might be due to the change in the interactions between the protein and micellar aggregates driven by the added salt. For 1:2 salts like $CaCl_2$ and $MgCl_2$, BSA was back-extracted with lower than 20% extraction efficiency. Maximum extraction efficiencies were attained at about pH=7 and pH=8 for monovalent and divalent salts, respectively. The addition of alcohols as cosurfactants led to an improvement in monovalent and divalent salts, respectively. From the CD spectra of BSA extracted to the aqueous phase, it was observed that denaturation of BSA was not significant. In certain back-extraction conditions, the extracted BSA showed even higher activity than the feed BSA.

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Precision Grinding System for Micro Core-pin (마이크로 코어 핀 정밀 연삭 시스템)

  • Yang, Ji-Kyung;Lee, In-Cheol;Kang, Dong-Seong;Han, Bong-Seok;Han, Yu-Jin;Lee, Jung-Woo;Song, Ki-Hyeok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.4
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    • pp.50-57
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    • 2017
  • In the injection molding process, a core that builds a space for a product is installed at the internal place in the mold and fabricated as the frame of the mold. In this make up, the fabricating partial form of the mold at a pin is a core pin. The core pin is finer because an injection mold produces miniaturization and integration. On the other hand, when the core is manufactured using the existing centerless grinder, it generates vibrations because of the lack of a fixed zig for a micro size workpiece. For this reason, an existing centerless grinder without a micron size fixed zig, makes a defective product due to vibration and deformation. In this study, a compact grinding system that can be installed using an existing centerless grinder was fabricated to make a micro size core pin. Using the compact grinding system, grinding experiment for core pin was carried out. The performance of the system was confirmed by measuring the surface roughness, roundness, and cylindricity.