• Title/Summary/Keyword: ASES

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Stability Evaluation of Vitamin-C Inclusion Complexes Prepared using Supercritical ASES Process (초임계 ASES 공정으로 제조된 Vitamin-C 포접복합체의 안정성 평가)

  • Yang, Jun-Mo;Kim, Seok-Yun;Han, Ji-Hyun;Jung, In-Il;Ryu, Jong-Hoon;Lim, Gio-Bin
    • KSBB Journal
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    • v.21 no.2
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    • pp.157-163
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    • 2006
  • A supercritical fluid process, called aerosol solvent extraction system(ASES), is especially suitable to the pharmaceutical, cosmetic and food industries due to its environmentally-friendly, non-toxic and residual solvent-free properties. In particular, the application of the ASES process to the processing of thermo-labile bioactive compounds has received attention of many scientists and engineers because of its low-temperature operating conditions. Unstable substances such as Vitamin-C and Vitamin-A can be effectively protected from degradation during the preparation process, because the ASES process is free from oxygen and moisture. In this study, Vitamin-C was formulated with 2-hydroxypropyl-${\beta}$-cyclodextrin (HP-${\beta$-CD) for enhancement of Vitamin-C stability and bioavailability using the ASES process. To investigate the influence of the preparation process on the stability of Vitamin-C, Vitamin-C/HP-${\beta}$-CD inclusion complexes were prepared using both conventional solvent evaporation method and ASES process, and stored in a 50 mM phosphate buffer solution of pH 7.0 at $25^{\circ}C$ for 24 hours. From the experimental results, the stability of the Vitamin-C/HP-${\beta}$-CD inclusion complex prepared from the ASES process was found to be much higher than that of pure Vitamin-C and the Vitamin-C/HP-${\beta}$-CD inclusion complex prepared by the solvent evaporation method. The stability of Vitamin-C was observed to increase with the decrease of temperature at a constant pressure or with the increase of pressure at a constant temperature.

Utilization of Supercritical Carbon Dioxide for the Preparation of 2-Hydroxypropyl-β-Cyclodextrin Microparticles and Their Inclusion Complexes with Ibuprofen (초임계 이산화탄소를 이용한 2-Hydroxypropyl-β-Cyclodextrin 미립자와 이부프로펜과의 포접복합체 제조)

  • Ryu, Jong-Hoon
    • Clean Technology
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    • v.19 no.3
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    • pp.212-218
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    • 2013
  • The microparticles of 2-hydroxypropyl-${\beta}$-cyclodextrin (HP-${\beta}$-CD) were prepared using aerosol solvent extraction system (ASES) by employing supercritical carbon dioxide as an antisolvent, The effects of various process parameters such as temperature, pressure, solution concentration and solution flow rate on the formation of HP-${\beta}$-CD microparticles were investigated. The HP-${\beta}$-CD microparticles prepared by the ASES process were observed to consist of agglomerates of nano-sized (50-200 nm) particles. When an aqueous solution of ethanol was used as a solvent for HP-${\beta}$-CD, the HP-${\beta}$-CD particles were found to be spherical in shape and to become larger as the water content increased. It was confirmed that the micronization of HP-${\beta}$-CD using the ASES process could enhance the inclusion efficiency of ibuprofen/HP-${\beta}$-CD complexes significantly.

Prospective Comparative Study of Arthroscopic Repair Versus Debridement for the Full-Thickness Tear of Upper Subscapularis (상부 견갑하 건 완전파열의 관절경 하 봉합술과 변연절제술의 전향적 비교)

  • Ko, Sang-Hun;Cha, Jae-Ryong;Lee, Chae-Chil;Park, Han-Chang;Shin, Seung-Myeong
    • Clinics in Shoulder and Elbow
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    • v.13 no.1
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    • pp.79-85
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    • 2010
  • Purpose: To evaluate the results from arthroscopic repair versus debridement for full-thickness tears of the upper subscapularis tendon. Materials and Methods: Ninety-nine patient outcomes were evaluated and compared prospectively. Sixty-nine patients with full-thickness tears of the upper subscapularis tendon underwent arthroscopic repair (group I) and thirty patients underwent simple debridement (group II) between May 2003 and October 2007. In all patients, the tear was localized to the superior one third of the upper subscapularis tendon. The results of the treatment were assessed by evaluating the UCLA, ASES, and VAS for pain and internal rotation strength scores before and after the operation. Results: In groups I and II, UCLA, ASES, VAS, and internal rotation muscle power (perfect score = 5) scores were improved after surgery. In comparing group I and group II, the UCLA and VAS scores were not significantly different (p>0.05), while the ASES and internal rotation strength scores were significantly different (p<0.05). Conclusion: The arthroscopic repair of full-thickness tears of the upper subscapularis tendon was a better surgical method than simple debridement.

Production of Gemcitabine-Loaded Poly (L-lactic acid) Microparticles Using Supercritical Carbon Dioxide: Effect of Process Parameters (초임계 이산화탄소를 이용한 Gemcitabine 함유 PLLA 미립자 제조: 공정 변수의 영향)

  • Joo, Hyun-Jae;Jung, In-Il;Lim, Gio-Bin;Ryu, Jong-Hoon
    • KSBB Journal
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    • v.26 no.1
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    • pp.69-77
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    • 2011
  • In this study, poly (L-lactic acid) (PLLA) microparticles containing gemcitabine hydrochloride were prepared by a supercritical fluid process, called aerosol solvent extraction system (ASES), utilizing supercritical carbon dioxide as antisolvent. The influence of process parameters such as temperature, pressure, $CO_2$ and solution flow rate, solution concentration, and feed ratio of drug to polymer on the morphology and characteristics of the microparticles was studied in detail. The gemcitabine-loaded microparticles exhibited a spherical shape with a smooth surface. The entrapment efficiency of gemcitabine increased with increasing temperature, solution concentration and $CO_2$ flow rate and with decreasing drug/polymer feed ratio. The maximum drug loading obtained from the ASES process was found to be about 11%. The ASES-processed PLLA microparticles containing gemcitabine showed a relatively high initial burst due to the presence of surface pores on the microparticles and the poor affinity between drug and polymer.

On Inferring and Characterizing Internet Routing Policies

  • Wang, Feng;Gao, Lixin
    • Journal of Communications and Networks
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    • v.9 no.4
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    • pp.350-355
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    • 2007
  • Border gateway protocol allows autonomous systems(ASes) to apply diverse routing policies for selecting routes and for propagating reachability information to other ASes. Although a significant number of studies have been focused on the Internet topology, little is known about what routing policies network operators employ to configure their networks. In this paper, we infer and characterize routing policies employed in the Internet. We find that routes learned from customers are preferred over those from peers and providers, and those from peers are typically preferred over those from providers. We present an algorithm for inferring and characterizing export policies. We show that ASes announce their prefixes to a selected subset of providers to perform traffic engineering for incoming traffic. We find that the selective announcement routing policies imply that there are much less available paths in the Internet than shown in the AS connectivity graph, and can make the Internet extremely sensitive to failure events. We hope that our findings will help network operators in designing routing policies.

Mini-open Rotator Cuff Repair Using Anterolateral Approach (전외측 도달법을 이용한 소절개 회전근 개 봉합술)

  • Cho, Chul-Hyun;Yeo, Kyung-Ki;Lee, Sung-Yoon;Jung, Gu-Hee
    • Clinics in Shoulder and Elbow
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    • v.13 no.1
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    • pp.86-91
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    • 2010
  • Purpose: To introduce mini-open rotator cuff repair using the anterolateral approach and evaluate its clinical outcomes and effectiveness. Materials and Methods: 59 consecutive cases of rotator cuff tearing which were treated with mini-open repair utilizing the anterolateral approach were evaluated. The population comprised 39 men and 20 women, with an average age of 56.6 years. An average follow-up time period was 26 months. Clinical outcomes were analyzed based on VAS, ADL, and ASES scores. Results: The average respective VAS, ADL, and ASES scores improved from 7.04, 12.37, and 35.32 preoperatively to 1.02, 27.20, and 90.08 postoperatively (p=0.000). There were 41 excellent, 11 good, 2 fair, and 5 poor results. There were satisfactory results in 52 cases (88.1%). There were no statistically significant differences between the final ASES scores and age, sex, duration of symptoms, tear size, and preoperative stiffness (p>0.05). Conclusion: Mini-open rotator cuff repair using the anterolateral approach effective in providing better visualization.

Arthroscopic Repair of Type II SLAP lesion with Bio-knotless Anchor (제 2형 SLAP 병변에 대하여 흡수성 봉합 나사못을 이용한 관절경적 봉합 수술의 임상적 결과)

  • Yum, Jae-Kwang;Chung, Hyung-Jin;Ra, Ho-Jong
    • Clinics in Shoulder and Elbow
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    • v.10 no.1
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    • pp.73-77
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    • 2007
  • Purpose: This study reports the clinical results of the arthroscopic repair of type II SLAP lesion with bio-knotless anchor. Materials and Methods: 25 cases of 25 patients (20 male, 5 female) were included in this study. The average age was 44.5 years old. Preoperative ASES score was average 44. Arthroscopic SLAP repair with 1 or 2 bio-knotless anchors were performed in all cases. The average follow up period was 15 months. Results: The ASES score improved to average 92.7 at last follow up period and 23 cases had full range of motion of the shoulder. 2 case had mild limited range of motion of the shoulder without any problem in normal activity. Conclusion: Arthroscopic repair with bio-knotless anchor in type II SLAP lesion is one of the good methods because of the good clinical results.

Treatment of the Septic Shoulder after Arthroscopic Rotator Cuff Repair in Diabetes Mellitus - A Case Report - (당뇨병 환자에서 관절경적 회전근 개 봉합술 후 발생한 화농성 견관절염의 치료 - 증례 보고 -)

  • Park, Jae-Hyun;Choi, Won-Ki;Kim, Se-Sik;Choi, Chang-Hyuk
    • Journal of the Korean Arthroscopy Society
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    • v.13 no.1
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    • pp.72-76
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    • 2009
  • Two diabetes mellitus patients treated by arthroscopy and associated procedure for an infection after arthroscopic rotator cuff repair were involved. The time interval from rotator cuff repair to symptom development was 18 days in average and arthroscopic debridement and associated procedure for infection applied in average 65 days after symptom development. Patient evaluation was done according to the KSS, ASES, UCLA and Constant Score. We used antibiotics for average 22.5 days after arthroscopic debridement and associated procedure, the infection was treated in average 4 months. At final follow-up, the mean KSS score was 82 points, the mean UCLA score was 33 points, the mean ASES score was 91 points, the mean Constant score was 71 points. All infections following arthroscopic rotator cuff repair were cured by arthroscopy and associated procedure. ROM and functional results were much improved, the pain and satisfaction were also much improved.

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Preparation and Characterization of Solid Dispersions of Itraconazole by using Aerosol Solvent Extraction System for Improvement in Drug Solubility and Bioavailability

  • Lee, Si-Beum;Nam, Kyung-Wan;Kim, Min-Soo;Jun, Seoung-Wook;Park, Jeong-Sook;Woo, Jong-Soo;Hwang, Sung-Joo
    • Archives of Pharmacal Research
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    • v.28 no.7
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    • pp.866-874
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    • 2005
  • The objective of this study was to elucidate the feasibility to improve the solubility and bioavailability of poorly water-soluble itraconazole via solid dispersions by using supercritical fluid (SCF). Solid dispersions of itraconazole with hydrophilic polymer, HPMC 2910, were prepared by the aerosol solvent extraction system (ASES) under different process conditions of temperature/pressure. The particle size of solid dispersions ranged from 100 to 500 nm. The equilibrium solubility increased with decrease (15 to 10 MPa) in pressure and increase (40 to $60^{\circ}C$) in temperature. The solid dispersions prepared at $60^{\circ}C$/15 MPa showed a slight increase in equilibrium solubility (approximately 27-fold increase) when compared to pure itraconazole, while those prepared at $60^{\circ}C$/10MPa showed approximately 610-fold increase and no endothermic peaks corresponding to pure itraconazole were observed, indicating that itraconazole might be molecularly dispersed in HPMC 2910 in the amorphous form. The amorphous state of itraconazole was confirmed by DSC/XRD data. The pharmacokinetic parameters of the ASES-processed solid dispersions, such as $T_{max},\;C_{max},\;and\;AUC_{0-24h}$ were almost similar to $Sporanox_{\circledR}$ capsule which shows high bioavailability. Hence, it was concluded that the ASES process could be a promising technique to reduce particle size and/or prepare amorphous solid dispersion of drugs in order to improve the solubility and bioavailability of poorly water-soluble drugs.

Prospective Clinical Research of the Efficacy of Platelet-rich Plasma in the Outpatient-based Treatment of Rotator Cuff Tendinopathy

  • Lee, Ho-Won;Choi, Kyung-Ho;Kim, Jung-Youn;Yang, Ik;Noh, Kyu-Cheol
    • Clinics in Shoulder and Elbow
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    • v.22 no.2
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    • pp.61-69
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    • 2019
  • Background: The purpose of this study is to compare the clinical outcomes of the control group and platelet-rich plasma (PRP) group among the patients who failed to respond to conservative treatment as outpatient-based therapy for rotator cuff tendinopathy, and to compare the clinical results of leukocyte-poor (LP) PRP and leukocyte-rich (LR) PRP. Methods: Inclusion criteria are (1) over 18-year-old, (2) patients with rotator cuff tendinopathy, no rotator cuff tear by radiologic diagnosis (ultrasonography or magnetic resonance imaging) within the last 3 months, and (3) not effective to conservative treatment for more than 1 month. Of the final 60 subjects, 33 patients in the exercise treatment group and 27 patients in the PRP injection group (LP-PRP, 13; LR-PRP, 14) were included. Clinical evaluation was carried out by assessing the outcomes of treatment using the Numeric Rating Scale pain score, the American Shoulder and Elbow Society (ASES) score, and the Constant score at baseline and at 3 and 6 months after the procedure. Results: There was a statistically significant difference in ${\Delta}ASES_{3months}$ ($ASES_{3months}-ASES_{first}$) score between the control and PRP groups (p=0.006). However, there was no statistical significance between LP-PRP and LR-PRP groups (p>0.05). Conclusions: This study showed that PRP injection was more effective than exercise therapy for the first 3 months. However, there was no difference between the LP-PRP group and the LR-PRP group. Regardless of the type of PRP, clinical application of PRP injection in patients with rotator cuff tendinopathy seems to be effective in early treatment.