• 제목/요약/키워드: Physical presence

검색결과 935건 처리시간 0.025초

Surface Modification of Polypropylene Membrane by ${\gamma}$ Irradiation Methods and their Solutes Permeation Behaviors

  • Shim, J. K.;Lee, S. H.;Kwon, O. H.;Lee, Y. M.;Nho, Y. C.
    • 한국막학회:학술대회논문집
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    • 한국막학회 1998년도 춘계 총회 및 학술발표회
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    • pp.99-101
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    • 1998
  • 1. Introduction : The conventional grafting polymerization technique requires chemically reactive groups on the surface as well as on the polymer chains. For this reason, a series of prefunctionalization steps are necessary for covalent grafting. The surface prefunctionalizational technique for grafting can be used to ionization radiation, UV, plasma, ion beam or chemical initiators. Of these techniques, radiation method is one of the useful methods because of uniform and rapid creation of active radical sites without catalytic contamination in grafted samples. If the diffusion of monomer into polymer is large enough to come to the inside of polymer substrate, a homogeneous and uniform grafting reaction can be carried out throughout the whole polymer substrate. Radiation-induced grafting method may attach specific functional moieties to a polymeric substrate, such as preirradiation and simultaneous irradiation. The former is irradiated at backbone polymer in vacuum or nitrogen gas and air, and then subsequent monomer grafting by trapped or peroxy radicals, while the latter is irradiated at backbone polymer in the presence of the monomer. Therefore, radiation-induced polymerization can be used to modification of the chemical and physical properties of the polymeric materials and has attracted considerable interest because it imparts desirable properties such as blood compatibility. membrane quality, ion excahnge, dyeability, protein adsorption, and immobilization of bioactive materials. Synthesizing biocompatible materials by radiation method such as preirradiation or simultaneous irradiation has often used $\gamma$-rays to graft hydrophilic monomers onto hydrophobic polymer substrates. In this work, in attempt to produce surfaces that show low levels of anti-fouling of bovine serum albumin(BSA) solutions, hydroxyethyl methacrylate(HEMA) was grafted polypropylene membrane surfaces by preirradiation technique. The anti-fouling effect of the polypropylene membrane after grafting was examined by permeation BSA solution.

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Investigation of Degradation Mechanism of Rabeprazole with Solid State Pharmaceutical Excipients

  • Ren, Shan;Tran, Thao Truong-Dinh;Tran, Phuong Ha-Lien;Rhee, Yun-Seok;Lee, Beom-Jin
    • Journal of Pharmaceutical Investigation
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    • 제40권6호
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    • pp.367-372
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    • 2010
  • Rabeprazole sodium (RPN) is known to be very unstable at acidic condition or some acidic pharmaceutical excipients such as acrylic acid polymer (carbomer 934) with carboxylic acids. Thus, degradation mechanism of binary blends of rabeprazole with pharmaceutical excipients in a solid state without using solvents at three different ratios (3:1, 1:1 and 1:3) was investigated using Fourier transform infrad (FTIR) spectroscopy. Alkalizer (MgO), neutral hydroxypropymethylcellulose (HPMC 4000) were also tested for comparison. The binary blends were stored under accelerated conditions ($40^{\circ}C$/75% relative humidity) for two weeks. The concentration of thioether rabeprazole from the binary blends with acidic carbomer 934 increased as the rabeprazole concentration decreased. In addition, the degradation half-life of rabeprazole as well as the relative peak area ratios obtained from FTIR spectra of S=O stretching at $1094.1\;cm^{-1}$ decreased consistently as the fraction of carbomer 934 increased due to its sensitivity between the basic benzimidazole nitrogen and carboxylic acid group of carbomer 934. The physical appearance also turned into strong brown color in the presence of carbomer 934. In contrast, there were no significant changes in the degradation kinetics of rabeprazole with MgO and HPMC 4000 in a solid state. This present study demonstrated that the solid-state compatibility test with the aid of HPLC chromatographic and FTIR spectral analyses could offer a valuable methodology to select suitable pharmaceutical excipients and to elucidate the degradation mechanism of RPN for drug formulations at the early formulation stages.

무인도서의 정의와 분류에 관한 소고 - 태안해안국립공원을 사례로 - (Suggestion for the Definition and Classification of Uninhabited Islands : A Case of Taeanhaean National Park)

  • 서종철;신영호
    • 한국지역지리학회지
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    • 제21권2호
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    • pp.342-354
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    • 2015
  • 태안해안국립공원에 포함된 무인도서를 대상으로 효율적인 관리가 가능하도록 무인도서 관련 용어의 정의를 제시하고 유형을 분류하였다. 무인도서를 규정하는 만조의 기준을 약최고고조위로 구체화하였고 만조 시에 잠기는 개체는 여로 구분하였다. 무인도서는 지리적 생태적 가치와 중요성을 고려하여 목본 식생의 정착 여부에 따라 무인도와 돌섬으로 구분하였다. 여는 약최저저조위를 기준으로 수중여와 간출여로 구분하였다. 만조 시에도 바다로 둘러싸이지 않는 경우는 무인도서에서 배제하였고, 간조 시에 지형적 생태적으로 연결되는 여러 개의 개체는 하나의 무인도서로 간주하였다. 이러한 기준을 활용하여 태안해안국립공원의 무인도서를 24개의 무인도와 14개의 돌섬, 12개의 여로 재분류하여 총 50개로 정리하였다. 이와 같은 기준을 전국의 무인도서에 확대해 적용한다면 무인도서를 관리하는 공공기관에서 도서분류의 국가표준을 마련하는데 유용하게 활용될 것이다.

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Enzymatic Hydrolysis of Crystalline Chitin in an Agitated Bead Reaction System and Its Reaction Characteristics

  • Lee, Yong-Hyun;Bae, Young-Ki;Jeong, Eui-Jun
    • Journal of Microbiology and Biotechnology
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    • 제6권6호
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    • pp.432-438
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    • 1996
  • Native crystalline chitin was hydrolyzed in an agitated bead reaction system using crude chitinase excreted from Aspergillus fumigatus JC-19. The reaction was enhanced significantly, and the concentration and yield of reducing sugar after 48 hours were measured to be 35.42 g/I (w/v) and 0.64, respectively, around 1.86 times higher than those of the conventional system that was carried out without glass beads. The effect of reaction conditions, such as the amounts of chitin, chitinase and glass beads, and the size of glass bead, were examined. Ball milled chitin was also hydrolyzed in the agitated bead reaction system, the conversion yield and reaction rate of ball milled chitin for 24 hours increased up to 0.87 and 48.02 g/I, respectively. Chitinase showed relatively high stability in the agitated bead reaction system, particularly in the presence of enzyme stabilizer, $Ca^{++}$, which played a critical role in preventing the deactivation of chitinase by the physical impact of glass beads. The variations of the structural features of chitin during the reaction were followed by SEM and X-ray diffraction, and the enhanced hydrolysis reaction was caused by both the fragmentation of chitin particles and the destruction of the crystalline structure owing to the synergic effects of the attrition of glass beads and the hydrolytic action of chitinase.

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Ergostane-Type Steroids from Korean Wild Mushroom Xerula furfuracea that Control Adipocyte and Osteoblast Differentiation

  • Lee, Seoung Rak;Choi, Jin Hee;Ryoo, Rhim;Kim, Jin-Chul;Pang, Changhyun;Kim, Seon-Hee;Kim, Ki Hyun
    • Journal of Microbiology and Biotechnology
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    • 제30권11호
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    • pp.1769-1776
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    • 2020
  • As part of our current work to discover structurally and/or biologically novel compounds from Korean wild mushrooms, we isolated five ergostane-type steroids (1-5) from the fruiting bodies of Xerula furfuracea via repeated column chromatographic separations and HPLC purification. The chemical structures of the isolated steroids were shown to be (22E,24R)-24-methylcholesta-4,22-diene-3,6-dione (1), ergosta-7,22-diene-3β,5α,6β-triol (2), ergosta-7,22-diene-3β,5α,6β,9α-tetraol (3), (22E,24R)-5α,8α-epidioxyergosta-6,22-diene-3β-ol-3-O-β-D-glucopyranoside (4), and (22E,24R)-5α,8α-epidioxyergosta-6,9,22-triene-3β-ol-3-O-β-D-glucopyranoside (5)based on comparison of the data regarding their spectroscopic and physical properties with those of previous studies. Notably, this is the first report on the presence of the identified steroids (1-5) in this mushroom. We tested compounds 1-5 to determine their effects on adipogenesis and osteogenesis in the mouse mesenchymal stem cell line C3H10T1/2 and found that compounds 4 and 5 suppressed the differentiation of stem cells into adipocytes. Notably, in addition to its suppressive effect on adipogenesis, compound 5 was also shown to promote the osteogenic differentiation of stem cells. These findings demonstrate that the bioactive compounds isolated might be effective for the treatment of menopause-associated syndromes, such as osteoporosis and obesity, as the isolated compounds were shown to suppress adipogenesis and/or promote osteogenesis of stem cells.

Tunisian phosphogypsum tailings: Assessment of leaching behavior for an integrated management approach

  • Zmemla, Raja;Sdiri, Ali;Naifar, Ikram;Benjdidia, Mounir;Elleuch, Boubaker
    • Environmental Engineering Research
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    • 제25권3호
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    • pp.345-355
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    • 2020
  • This study has been carried out to evaluate the leaching behavior of Tunisian phosphogypsum (PG) tailings in Skhira city (southern Tunisia). Two PG samples, including old and freshly deposited samples, were characterized in terms of physical, geotechnical, mechanical, chemical and mineralogical properties. Special attention was paid to their leaching behavior when subjected to standard leaching tests. Our results indicated that both samples are mainly composed of more than 31.85% CaO and 31.4% SO3, indicating the predominance of gypsum. This was further confirmed by XRD patterns that revealed the presence of characteristic reflections of gypsum, brushite, quartz and Maladrite. Compressive strength after 90 d exceeded 769 kPa, but still lower than that of natural sand (1,800 kPa). Leaching test was proposed as an appropriate method to determine the released contaminants from PG. The obtained results showed that Fluorine and Phosphorus are the most released elements from PG with 40 and 30%, respectively. The released Se, Cd, and Zn were the only trace elements that exceeded the threshold limits. It seemed that leached element concentrations were independent aging or particle size of the PG. Based on the assessment of leaching behavior, an integrated management approach of the PG deposits was proposed.

스포츠 선수에서 발생한 내과하 부골증 (Os Submalleolare in Sports players)

  • 이경태;양기원;김재영;임태강
    • 대한족부족관절학회지
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    • 제7권2호
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    • pp.218-222
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    • 2003
  • Purpose: The objective of this study was to define the Os submalleolare as an any ossicles below medial malleolus of tibia and to determine the characteristics of clinical and radiological characteristics and to evaluate results of surgical treatment of Os submalleolare in sports player group. Materials and Methods: Twenty-two patients with Os submalleolare were identified between November, 1, 1998 and June, 30, 2002. Results: The mean age was 18.3 years. All patient were male and soccer players comprised 71%(20 cases). Associated disease were 8 cases(29%) of chronic ankle instabilities, one case(4%) of anterior impingement syndrome and one (4%) of plantar fascitis. The most common clinical symptom was pain during walking and sports activity and sign was tenderness around medial malleolus. Only simple radiograph could reveal presence of ossicle and differentiate with acute fracture. If symptom and sign obscured, Bone scan(7 cases) and MRI(3 cases) identify causes of pain and tenderness. As a surgical treatment, all bony fragment caused symptom and sign were eliminated and medial collateral ligament was reattached meticulously. Associated chronic ankle instability were present, modified Brostrom procedure was done simultaneously. On follow-up, The symptomatic pain were wholly disappeared at average 2.2 months (1-6months) after operation. On one year follow-up, all patients have been daily life without any complaints and have gone back to the game within three months. Conclusion: as submalleolare have relatively rare incidence in sports players and most common clinical symptom and sign is tenderness on medial malleolar area of ankle, can be diagnosed both physical examination and plain X-ray film. As a treatment, Removal of ossicle and reattachment of MCL could obtain excellent or good results.

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Immunomodulatory Effects of Fucoidan on NK Cells in Ovariectomized Rats

  • NamKoong, Seung;Kim, Ye-Jin;Kim, Tae-Seong;Sohn, Eun-Hwa
    • 한국자원식물학회지
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    • 제25권3호
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    • pp.317-322
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    • 2012
  • In this study we investigated the effects of supplementation with fucoidan from brown alga on the function of natural-killer (NK) cells to evaluate the possibility as an immunomodulator in ovariectomized (OVX) rats. A total of 18 female Wistar rats (six weeks) were used this study and 12 rats were OVX, and the rest of rats were sham-operated. The sham and one OVX group were fed standard diet, and the remaining OVX group received fucoidan (0.05% supplemented diet). After 12 weeks of supplementation, rats were sacrificed to assess the tumoricidal activity of the NK cells and the NO-iNOS regulation from splenocytes. The mass of body and the immune organs such as spleen and thymus were also studied. In OVX rats, body and thymus weights increased, however fucoidan supplementation did not change the body mass and organs weight compared to OVX group. Fucoidan supplementation increased NK cell activity and reduced NO-iNOS production in OVX rats. Ex vivo treatment of fucoidan increased NK cell activity in splenocytes from shame and OVX rats. Ex vivo, we confirmed that fucoidan partially reduced the NK cell activity in the presence of iNOS inhibitors in OVX-splenocytes. These results indicate fucoidan supplementation has a NK cell tumoricidal activity, which are regulated by the iNOS production in OVX rats. This suggests that fucoidan is useful for potential therapeutic strategies as a nutrient in regulating the NK cells in postmenopausal osteoporosis patients.

NIC간호중재분류체계를 이용한 수술실 핵심간호중재분석 (Analysis of Core Interventions of Operating Room using Nursing Intervention Classification)

  • 이윤영;박광옥
    • 간호행정학회지
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    • 제8권3호
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    • pp.361-372
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    • 2002
  • Purpose : The purpose of study was to identify to analysis of core nursing interventions performed by Operating Room nurses. Method : The subjects of the study were arbitrarily selected nurses(n=104) working in Operating Room. The period for data collection was 15 days from July, 15, 2002 to July, 30. 2002. The instrument for study was 486 Nursing Interventions Classification developed by McClosky & Bulechek(2000) and was translated into Korean. In 486 nursing interventions, 57 nursing interventions were selected by more than half of 47 professional nurses group of Operating Room. 57 nursing interventions were used as a secondary questionnaire. In the secondary questionnaire, labels and definitions of all 57 interventions were listed. The collected data were self reported by Operating Room nurses. The data were analysed with SPSS program. Result : In 57 nursing interventions, the 'Behavior' domain was the most frequently used. Core interventions of Operating Room were performed several times a day by more than 50% of Operating Room nurses. Core interventions of Operating Room were 16 Core interventions, 7 classes, 5 domains. In the core interventions, the 'Physiological:Complex' domain was the most frequently used. Core interventions of Operating Room were Surgical Preperation, Infection Control:Intraoperative, Surgical Precautions, Fall Prevention, Documentation, Surgical Assistance, Environmental Management:Safety, Skin Surveillance, Physical Restraint, Pressure Ulcer Prevention, Environmental Management:Comfort, Infection Protection, Presence, Emotional Support, Specimen Management, Shift Report. Conclusion : Core interventions of Operating Room have implications for nursing care practice, nursing education, nursing research, and nursing information system in Operating Room.

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항암화학요법 관련 말초신경병증에 적용한 비약물적 중재의 효과: 체계적 문헌고찰 및 메타분석 (Effectiveness of Non-Pharmacologic Interventions in Chemotherapy Induced Peripheral Neuropathy: A Systematic Review and Meta-Analysis)

  • 오복자;김유림
    • 대한간호학회지
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    • 제48권2호
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    • pp.123-142
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    • 2018
  • Purpose: This study was conducted to evaluate the effectiveness of non-pharmacologic interventions in chemotherapy-induced peripheral neuropathy (CIPN). Methods: PubMed, Cochrane Library CENTRAL, EMBASE, CINAHL, and several Korean databases (Until August 2017) were searched. The main search strategy combined terms for peripheral neuropathy and presence of neoplasms. The risk of bias was assessed using the Cochrane's Risk of Bias tool for randomized studies and the Risk of Bias Assessment tool for non-randomized studies. To estimate the effect size, a meta-analysis of the studies was performed using the Rev Man 5.3 program of the Cochrane Library random-effects models were used in the analyses. Results: Twenty-two studies with a total of 954 participants met the inclusion criteria. Of the 22 studies, 12 were used to estimate the effect size of the non-pharmacologic interventions. The non-pharmacologic interventions used in patients with CIPN were exercise, acupuncture, massage, and foot bath. The acupuncture significantly reduced CIPN symptoms and signs (d=-0.71) and CIPN pain (d=-0.73) (p<.001). Massage and foot bath were also effective in reducing CIPN symptoms (d=-0.68; 95% CI=-1.05, -0.30; p<.001; $I^2=19%$).Exercises were effective in improving muscle strength and endurance(d=-0.55) and quality of life (d=-2.96), but they were not significantly effective in improving CIPN. Conclusion: Although these results provide little evidence of the effectiveness of acupuncture, massage, and foot bath in the treatment of CIPN, they suggest that these interventions can reduce CIPN symptoms in patients with cancer. However, the findings of this study should be interpreted with caution as there is a relative lack of data in this field, and additional well-designed studies are needed. PROSPERO registration: CRD42017076278.