• Clinical and Experimental Pediatrics
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• 제62권9호
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• pp.344-352
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• 2019

Background: Ventilator dependency constitutes a major problem in the intensive care setting. Malnutrition is considered a major determinant of extubation failure, however, attention has been attracted to modulating carbon dioxide production through decreasing carbohydrate loading and increasing the percent of fat in enteral feeds. The detected interrelation between substrate oxidation and ventilation outcome became the base of several research to determine the appropriate composition of the nonprotein calories of diet in ventilated patients. Purpose: We aimed to assess the effect of high-fat dietary modification and nutritional status on ventilatory and final outcomes of pediatric intensive care. Methods: Fifty-one ventilated children (1 month to 12 years of age) with pulmonary disease who could be enterally fed, in the Cairo University Pediatric intensive care unit, were divided into 2 groups: group A included 25 patients who received isocaloric high-fat, low-carbohydrate diet; group B included 26 patients who received standard isocaloric diet. Comprehensive nutritional assessment was done for all patients. Results: Group A had a significant reduction in carbon dioxide tension, but no similar reduction in the duration or level of ventilatory support. Assisted minute ventilation was predicted by weight-for-age and caloric intake rather than the type of diet. Poor nutritional status was associated with higher mortality and lower extubation rates. Mild hypertriglyceridemia and some gastrointestinal intolerance were significant in group A, with no impact on the adequacy of energy or protein delivery. Conclusion: The high-fat enteral feeding protocol may contribute to reducing carbon dioxide tension, with mild hypertriglyceridemia and negligible gastrointestinal intolerance as potential adverse effects. Optimization of nutritional status rather than dietary modification may improve ventilatory and survival outcomes in critically ill-ventilated children.

• Journal of Veterinary Science
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• 제23권5호
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• pp.78.1-78.13
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• 2022

Background: Florfenicol might be ineffective for treating Staphylococcus aureus small colony variants (SCVs) mastitis. Objectives: In this study, florfenicol-loaded chitosan (CS)-sodium tripolyphosphate (TPP) composite nanogels were prepared to allow targeted delivery to SCV infected sites. Methods: The formulation screening, the characteristics, in vitro release, antibacterial activity, therapeutic efficacy, and biosafety of the florfenicol composite nanogels were studied. Results: The optimized formulation was obtained when the CS and TPP were 10 and 5 mg/mL, respectively. The encapsulation efficiency, loading capacity, size, polydispersity index, and zeta potential of the optimized florfenicol composite nanogels were 87.3% ± 2.7%, 5.8% ± 1.4%, 280.3 ± 1.5 nm, 0.15 ± 0.03, and 36.3 ± 1.4 mv, respectively. Optical and scanning electron microscopy showed that spherical particles with a relatively uniform distribution and drugs might be incorporated in cross-linked polymeric networks. The in vitro release study showed that the florfenicol composite nanogels exhibited a biphasic pattern with the sustained release of 72.2% ± 1.8% at 48 h in pH 5.5 phosphate-buffered saline. The minimal inhibitory concentrations of commercial florfenicol solution and florfenicol composite nanogels against SCVs were 1 and 0.25 ㎍/mL, respectively. The time-killing curves and live-dead bacterial staining showed that the florfenicol composite nanogels were concentration-dependent. Furthermore, the florfenicol composite nanogels displayed good therapeutic efficacy against SCVs mastitis. Biological safety studies showed that the florfenicol composite nanogels might be a biocompatible preparation because of their non-toxic effects on the renal tissue and liver. Conclusions: Florfenicol composite nanogels might improve the treatment of SCV infections.

• Journal of Microbiology and Biotechnology
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• 제34권3호
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• pp.663-672
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• 2024

The use of nanoparticles as a delivery system for a specific antigen could solve many limitations of mucosal vaccine applications, such as low immunogenicity, or antigen protection and stabilization. In this study, we tested the ability of nasally administered chitosan nanoparticles loaded with glycoprotein B of murine cytomegalovirus to induce an immune response in an animal model. The choice of chitosan nanoparticle type was made by in vitro evaluation of sorption efficiency and antigen release. Three types of chitosan nanoparticles were prepared: crosslinked with tripolyphosphate, coated with hyaluronic acid, and in complex with polycaprolactone. The hydrodynamic size of the nanoparticles by dynamic light scattering, zeta potential, Fourier transform infrared spectroscopy, scanning electron microscopy, stability, loading efficiency, and release kinetics with ovalbumin were evaluated. Balb/c mice were immunized intranasally using the three-dose protocol with nanoparticles, gB, and adjuvants Poly(I:C) and CpG ODN. Subsequently, the humoral and cell-mediated antigen-specific immune response was determined. On the basis of the properties of the tested nanoparticles, the cross-linked nanoparticles were considered optimal for further investigation. The results show that nanoparticles with Poly(I:C) and with gB alone raised IgG antibody levels above the negative control. In the case of mucosal IgA, only gB alone weakly induced the production of IgA antibodies compared to saline-immunized mice. The number of activated cells increased slightly in mice immunized with nanoparticles and gB compared to those immunized with gB alone or to negative control. The results demonstrated that chitosan nanoparticles could have potential in the development of mucosal vaccines.

• 대한간호학회지
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• 제29권2호
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• pp.215-224
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• 1999

The study was conducted to centum the construct of individual perception and preference for work characteristics as personal factors influencing Korean nurses' job satisfaction. The subjects of the study were 231 nurses who are currently working in intensive care units and have been for a minimum of 6 months. The study used the Staff Perception and Preference Scale(Song et al., 1997) to measure the individual's perception and preference on the technical. practice. and management components of the ideal work environment. The Korean version of the Staff Perception and Preference Scale consists of 16 items on perception and 13 on preference with each item related on a scale from 1(not at all) to 4(a great deal). Psychometric testing revealed that the preference and perception scale is internally consistent with Chronbach's alphas of .83 for perception scale arid .80 for preference scale. The subscales of the perception and preference scale also showed acceptable reliability for the early stage of the development of the instruments with Chronbach alphas of .62-.76 and .69-.83 respectively. Criterion-related validity of the scale was tested by examining correlations with individual growth need that is conceptually close to individual preference. but not to individual perception. Individual growth need was significantly related to individual preference(r＝.63, p<.05), but the correlation with the perception scale was not significant. A separate factor analysis for the each of perception and preference scales was performed with a three-factor loading solution based on a previous study. The results on the staff perception scale confirmed with varimax rotation that the items were cleanly and strongly loaded on technique. practice and management components, which together explained 50.7% of the variance. The factor analysis on the staff preference scale also yielded a three factor solution that explained 56.7% of the variance. but items on technique and management components were loaded together. This phenomena may due to the current nursing delivery system in Korea where nurses never experience either shared governance nor case management, and as a results they may not be able to consider management roles as their potential extended roles. Therefore, more efforts should be given to enhance nurses' autonomy and decision making in the technique, practice and management components of their work environment. Meanwhile, there is a need for continuously confirming and developing tools for individual perception and preferences to effectively enhance job satisfaction among Korean nurses through innovative work environments.

• 공업화학
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• 제26권2호
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• pp.165-172
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• 2015

쿼세틴과 쿼세틴의 배당체인 루틴은 천연 항산화제로 잘 알려진 플라보노이드이다. 본 연구에서는 플라보노이드(쿼세틴과 루틴)를 담지한 양이온 리포좀을 제조하여 세포 및 피부 투과성과 자외선(UVA)에 대한 HaCaT 세포 보호 효과를 평가하였다. 빈 양이온 리포좀의 입자 크기는 100~130 nm이며, 입자 표면 전위는 + 33.05 mV를 나타내었다. 포집효율은 루틴을 담지한 리포좀과 양이온 리포좀이 쿼세틴을 담지한 경우보다 높았다. 세포 내 이입율 비교결과, 양이온 리포좀이 일반 리포좀에 비해 약 5배 정도 높음을 확인했다. In vitro 상에서, 쿼세틴과 루틴이 용해된 PBS (phosphate-buffered saline) 수용액, 동량의 쿼세틴과 루틴을 담지한 리포좀과 양이온 리포좀의 피부투과율을 비교하였다. 양이온 리포좀에 담지하였을 경우 가장 높은 피부투과율을 보였다. 플라보노이드를 담지한 양이온 리포좀의 자외선(UVA $25J/cm^2$)에 대한 HaCaT 세포 보호 효과를 측정한 결과, 자외선만 조사한 군에 비해 플라보노이드 담지 양이온 리포좀을 처리한 군에서 높은 세포 보호 효과를 보였다. 결과적으로, 양이온 리포좀은 플라보노이드를 피부 속으로 전달하는데 있어서 매우 유용한 피부 전달 시스템임을 확인하였다. 따라서, 세포 보호 및 피부 흡수 증진 효과를 가지는 양이온 리포좀은 항노화 및 항산화 화장품 제형으로써 활용 가능성이 있음을 시사한다.

• Macromolecular Research
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• 제13권3호
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• pp.167-175
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• 2005

This review explores recent works involving the use of the self-assembled nanoparticles of bile acid-modified glycol chitosans (BGCs) as a new drug carrier for cancer therapy. BGC nanoparticles were produced by chemically grafting different bile acids through the use of l-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC). The precise control of the size, structure, and hydrophobicity of the various BGC nanoparticles could be achieved by grafting different amounts of bile acids. The BGC nanoparticles so produced formed nanoparticles ranging in size from 210 to 850 nm in phosphate-buffered saline (PBS, pH=7.4), which exhibited substantially lower critical aggregation concentrations (0.038-0.260 mg/mL) than those of other low-molecular-weight surfactants, indicating that they possess high thermodynamic stability. The SOC nanoparticles could encapsulate small molecular peptides and hydrophobic anticancer drugs with a high loading efficiency and release them in a sustained manner. This review also highlights the biodistribution of the BGC nanoparticles, in order to demonstrate their accumulation in the tumor tissue, by utilizing the enhanced permeability and retention (EPR) effect. The different approaches used to optimize the delivery of drugs to treat cancer are also described in the last section.

• 공업화학
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• 제24권6호
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• pp.639-644
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• 2013

본 연구에서는 화장품 소재로서 항염, 항노화 효능이 있는 두충 추출물을 담지한 에토좀을 제조하였고, 이들 에토좀이 안정한지를 확인하기 위하여 4주 동안 입자크기, 물리적 특성 및 포집효율을 측정하였다. 0.01~0.05% 두충 추출물을 담지한 에토좀은 4주 동안 침전이나 분리 현상이 나타나지 않았다. 이들 에토좀의 평균 입자 크기는 134.6 nm였고, 단분산 형태를 나타내었다. 0.05% 두충 추출물을 함유한 에토좀의 입자 크기는 151.15 nm였으며, 포집 효율은 81.79%로 에토좀 중 가장 큰 포집효율을 나타내었다. 0.05% 두충 추출물을 담지한 에토좀을 이용하여 피부 투과 실험을 수행하였다. 두충 추출물의 총 피부 투과량은 에토좀(77.16%) > 리포좀(62.80%) > 에탄올 용액(41.59%) 순으로 나타났다. 결과적으로 0.05% 두충 추출물을 담지한 에토좀은 피부 전달에 효과적이며, 식물 추출물을 함유하는 화장품 제형으로서 사용 가능성이 있음을 시사한다.

• 대한화장품학회지
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• 제30권3호
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• pp.295-305
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• 2004

콜로이드와 계면화학은 표면적과 표면에너지의 학문이다. 계면상의 위치에 따라서 분자밀도, 분자간의 상호작용력, 분자 배향성 그리고 반응성이 달라진다는 것은 흥미있는 주제가 되고 있다. 이러한 계면에너지가 중요하게 작용하는 시스템으로서 회합체, 에멀젼, 입자분산, 거품, 2차원적 표면이나 필름을 들 수 있다. 특히 나노 입자에 관련된 생체 적합성 재료를 사용하여 약물 전달체와 화장품 나노 소재로 이용하는데 관심이 고조되고 있다. 나노 입자는 수 nm에서 수백 nm 크기를 갖는, 넓은 표면적을 가진 콜로이드 상의 불균일 분산 입자의 일종이다. 지금까지 나노 입자의 제조, 특성 규명, 나노입자를 이용한 약물 봉입에 관한 연구가 활발히 이루어져 약물 전달체로서의 가능성이 충분히 입증되었다. 또한 난용성분 가용화 나노소재, 피부 흡수 증진용 나노소재, 자외선 차단용 나노소재, 안정화용 나노소재, 서방형 나노소재 등의 화장품 연구에 생체적합 나노전달체를 이용한 예가 보고되었다. 나노/마이크로 입자 시스템은 제조방법과 형태에 따라 나노/마이크로 스피어, 나노/마이크로 캡슐, 나노/마이크로 에멀젼, 폴리머 마이셀, 리포좀 등으로 구분된다. 수용액상에서 자기 회합체를 구성하는 나노수준의 폴리머 마이셀입자, 고농도, 고활성 물질에 대하여 농도 및 활성을 일정하게 제어할 수 있는 나노/마이크로 캡슐, 단일 이중층 또는 다층(100~800 nm)을 형성하여 여러 생리 환성 물질의 전달체로 이용되는 리포솜(liposome)에 대하여 제조방법과 산업의 응용에 대해 소개하였다.

• Journal of Pharmaceutical Investigation
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• 제30권4호
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• pp.241-246
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• 2000

To develop a sustained-release preparation containing ketorolac tromethamine, two sustained-release pellet formulations were evaluated with a pharmacokinetic study as compared with a conventional commercial tablets (10 mg $Tarasyn^{TM}$, Roche Korea Ltd.). Two sustained-release formulations were as follows; formulation A was composed of an inner layer containing 75% of drug coated with $Eudragit^{TM}$ RS 100 membrane and an outer layer containing 25% of drug mixed with $Eudragit^{TM}$ NE30D, and formulation B was composed of only an inner layer containing 100% of drug coated with $Eudragit^{TM}$ RS 100 membrane. The dissolution test was performed for two formulations. In case of conventional tablets, 2.5 mg of drug per a dose was administered orally into male Albino rabbit (2.0-2.3 kg of body weight) 3 times at intervals of 4 hours. In case of two sustained formulations, 7.5 mg of drug was administered once orally. Blood samples were withdrawn periodically after the administration, and the blood concentration was determined by HPLC. The conventional tablets showed very high peak-trough fluctuation between administered doses, but two sustained formulations showed less fluctuation. Formulation A with the loading dose showed the time to reach minimum effective concentration (MEC) i.e. the onset time was less than 20 min, while Formulation B had more than 1 hr of the onset time. Formulation A had the more constant plasma level than formulation B. However, formulation B had a time lag, so the plasma level was less than MEC for an initial period of 1 hr. In formulation A, the plasma level was maintained within the therapeutic window $(0.3-5\;{\mu}g/ml)$ for a long period. Formulation A was thought to be an ideal sustained-release formulation for ketorolac tromethamine oral delivery system.

• 한국가스학회지
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• 제7권2호
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• pp.33-41
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• 2003

LPG는 사용, 저장, 생산 과정뿐만 아니라 이송 중에도 많은 잠재위험(Hazard)을 갖고있다. 소규모의 수요처일 경우, LPG 용기를 적재한 차량에 의해 지역 사업자에 의하여 배달된다. 만약 도심지역에 가스용기를 적재한 차량에 폭발사고가 발생한다면 주변지역에 재산 피해뿐 아니라 상당한 인명피해를 초래할 것이다 본 연구에서는 LPG 누출 사례연구를 통하여 가스용기를 이용한 LPG의 운반 중에 사고의 원인이 되는 잠재위험을 확인한 후 사고발생 시나리오를 작성하고 발생 가능성과 피해결과를 예측하는 위험성(risk)의 정량적 분석을 하였다. 본 연구에서는 위험분석 프로그램을 Excel과 Visual Basic으로 프로그래밍 하여, ETA(Event Tree Analysis)법으로 LPG 운반도중 발생할 수 있는 사고의 빈도수를 구한 뒤, 이를 바탕으로 폭발로 인한 피해 범위 및 피해정도를 도출하였다. UVCE의 경우, 가스용기에서 누출되어 증발된 LPG에 대하여 사고현장주변에서 10m 이내에서는 심각한 구조적 손상을 보이며, 150m 이상에서도 유리가 파열되는 심각한 손상확률을 보였다. 그리고 TNT 상당법으로 Probit 결과, 10분간 누출되었을 때 40m 지점에서 유리창의 $75\%$가 깨졌으며, 20m 지점에서 $16\%$, 40m 지점에서는 $10\%$의 구조적 손상을 보였다.