• 대한한방내과학회지
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• 제39권6호
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• pp.1206-1224
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• 2018

Purpose: This systematic review was planned and performed in order to determine the clinical effectiveness of acupuncture for non-alcoholic fatty liver disease (NAFLD). Methods: We searched related randomized controlled trials in several medical online databases, including China National Knowledge Infrastructure (CNKI), Excerpta Medica dataBASE (EMBASE), Public/Publisher MEDLINE (PubMed), Cochrane Central Register of Controlled Trials (CENTRAL), National Digital Science Library (NDSL), and Research Information Sharing Service (RISS). NAFLD related outcomes were extracted from the included trials and meta-analyzed. Results: From the 8 included trials, the values of the following examinations were extracted: liver ultrasonography, liver CT, body fat CT, aspartate transaminase (AST), alanine transaminase (ALT), gamma-glutamyltransferase (GGT), total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, fasting blood sugar (FBS), hosmeostatic model assessment for insulin resistance (HOMA-IR), weight, body mass index (BMI), waist hip ratio (WHR), obesity degree, body fat mass, body fat rate, leptin, malondialdehyde (MDA), and super oxide dismutase (SOD). In the 4 outcomes, cure rate in liver ultrasonography (RR=1.56; 95%CI=1.05~2.31; P=0.03), cure rate in liver CT (RR=2.23; 95%CI=1.33~3.72; P=0.002), TC (MD=-0.78; 95%CI=-1.41~-0.15; P=0.02), and TG (MD=-2.05; 95%CI=-3.88~-0.21; P=0.03), acupuncture was more effective than the control intervention. Conclusions: In this meta-analysis, acupuncture relieved hepatic steatosis, and reduced TC, and TG in NAFLD patients. more well-planned studies are still needed due to the heterogeneity and the considerable methodological flaws in the analyzed trials.

• Composites Research
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• 제15권2호
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• pp.40-47
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• 2002

이관능성 에폭시 수지인 DGEBA와 DGEBF를 양이온 촉매인 BQH를 사용하여 전자선(electron-beam) 경화 기술에 의해 경화하였다. 그리고 수지의 구조적 차이가 열안정성과 경화동력학에 미치는 영향을 연구하였다. 실험적 결과에 의하면, Horowitz-Metzger 법에 의한 분해 활성화 에너지는 DGEBA의 경우가 높았지만 적분 열분해 온도(IPDT)는 DGEBA가 DGEBF 보다 낮았다. 이것은 DGEBF 주사슬의 수소 결합으로 인해 가교밀도가 높아졌기 때문인 것으로 사료되며, 근적외선 분광기(NIRS)를 사용하여 $5235\;cm^{-1}$와 $7000\;cm^{-1}$에서의 hydroxyl band의 증가로 확인하였다.

• Composites Research
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• 제31권4호
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• pp.171-176
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• 2018

인공 건식 접착 구조를 위한 새로운 마이크로-나노 계층구조 제작기법을 제안하였으며, 모세관법을 활용한 마이크로 구조 내 나노 소재 정렬에 대한 기초 연구를 수행하였다. 다중 벽 탄소나노튜브(MWCNT)와 폴리디메틸실록산(PDMS) 혼합물의 제작 조건에 따른 경화도 및 점도 특성을 분석하고, 이로부터 몇 가지 제작 조건을 결정하였다. MWCNT-PDMS 마이크로 구조 제작 후 단면 분석을 통해 PDMS내 MWCNT의 정렬 특성을 분석한 결과, 제작 온도와 상대 경화도가 낮을 경우 MWCNT의 정렬도가 우수하며, 단위 면적당 MWCNT의 밀도는 제작 온도나 상대 경화도에 영향을 적게 받는 것으로 확인되었다.

• Elastomers and Composites
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• 제58권3호
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• pp.136-141
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• 2023

Polyacrylic rubber (ACM) is well known for its excellent heat resistance and chemical stability. Additionally, its performance can be readily manipulated by modifying its functional groups, rendering it highly attractive to various industries. However, extreme climate changes have necessitated an expansion of the operating temperature range and lifespan of ACM products. This requires the optimization of both the compounding process and functional-group design. Hence, we investigated the relationship between the cross-linking system and mechanical properties of an ACM with a carboxylic cure site. The crosslink density is determined by chemical kinetics according to the structure of additives, such as diamine crosslinkers and guanidine accelerators. This interaction enables the manipulation of the scotch time and mechanical properties of the compound. This fundamental study on the correlation analysis between cross-linking systems, physical properties, and storage stability can provide a foundation for material research aimed at satisfying the increasingly demanding service conditions of rubber products.

• Elastomers and Composites
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• 제59권1호
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• pp.34-41
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• 2024

In this study, the effects of the type and content of silica on the mechanical and tear properties of chloroprene rubber (CR), which is mainly used as a jacket material for mining cables, were studied. The crosslinking density (ΔM) and reinforcing factor (α_f) defined using cure characteristics increased with increasing silica content, whereas the cure rate decreased. The hardness, tensile strength, and modulus of the CR compounds increased depending on the silica content and structural development. The reinforcing behavior of the silica-filled CR compounds according to the silica type and content showed the best fit with the Thomas equation of the predictive model. Tear strength was evaluated using two standard test methods, ASTM D470 and DIN VDE 0472-613, and the results were compared. The tear strength increased as the silica content increased, regardless of the test method, and the different tear strengths obtained by the two standard test methods showed a linear relationship with each other, indicating a high correlation.

• Journal of Pharmaceutical Investigation
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• 제36권2호
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• pp.83-87
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• 2006

Poly(acrylic acid) (PAA) was identified to possess good mucoadhesive properties ensuring its application to extend the retention times of the formulations at the oral cavity, intended route of administration using the polymer. In the noncross-linked state, PAA will swell and become eroded owing to the presence of salivary flow from the site of application. The formation of cross-links between the polymer chains will allow swelling but prevents the erosion of the dosage form. In the current study, cross-linking was achieved by esterification of the PAA chains with sucrose. The density of crosslinking was modified by changing sucrose concentration and the duration of cure time. The cross-linking density of the polymer hydrogel was assessed by equilibrium swelling studies. The mucoadhesion testing method allowed a comparative study of the hydrogels prepared. An inverse relationship between equilibrium swelling and peak detachment force showed that increased PAA chain density per unit area enhanced the mucoadhesive interaction.

• 동국한의학연구소논문집
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• 제2권1호
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• pp.155-166
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• 1993

Geukhachukeutang is used to cure blood stasis in Oriental Medicine. In order to investigate medical value on intravascula coagulation and contusion blood stasis, the effect of Platelet number, Fibrinogen quantity, Prothrombin time, FOP density, Paw edema increasing rate after prescribing Geukhachukeutang concentration liquid orally were observed. The obtained results are summerized as follows ; 1. Platelet number and Fibrinogen quantity are significantly increased, and Prothrombin time and FOP density are significantly decreased by Geukhachukeutang after inducing intravascula coagulation. 2. Platelet number and Fibrinogen quantity are not significantly increased, and Prothrombin time is not significantly decreased either, by Geukhachukeutang after inducing contusion blood stasis but Paw edema increasing rate is remarkablely decreased in three or four hours of the groups of prescribing. According to the above results, Geukhachukeutang will be used for contusion blood stasis and Intravascula coagulation effectively owing to being accepted as a favorable operation on Platelet number, Fibrinogen quantity, Prothrombin time, FDP density and Paw edema increasing rate.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.321-322
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• 2006

In many manufacturing processes such as web formation, manufacturing of paper and nonwoven, fabric weaving, etc., planar sheets are transported and at the same time appropriate tension is imposed. The input material rolled up on beams is fed by unwinding the beam and the processed is then taken up on beams by winding it. While processed, the planar sheets are thrown under the processing load of impulse form, which causes irregular thickness of the processed sheet. To improve the quality of the product, a dynamic model is needed and the dynamic characteristics is to be analyzed by simulation. This study shows that density variation dynamics of the in-process-sheet in the machine direction can be described at each moment of disturbing impacts in forms of difference equations, while the impacts and tension, the time-dependency of the material properties were taken into account. Simulation showed the most serious variation of the density occurred in the process starting phase. The starting velocity curve with step form showed the least variation of the density. As the time order of the function of the starting velocity cure becomes higher, the density variation gets greater.

• Elastomers and Composites
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• 제54권1호
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• pp.54-60
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• 2019

The rapid development of the automobile industry is an important factor that led to the dramatic development of synthetic rubber. The tread part of tire that comes in direct contact with the road surface is related to the service life of the tire. Rubber compounds used in tire treads are often blended with SBR (styrene-butadiene rubber) and BR (butadiene rubber) to satisfy physical property requirements. However, when two or more kinds of rubber are blended, phase separation and silica dispersion problems may occur due to non-uniform mixing of the rubber. Therefore, in this study, we synthesized an SBR copolymer with the same composition as that of a typical SBR/BR blend compound by controlling butadiene content during ESBR (emulsion styrene-butadiene rubber) synthesis. Subsequently, silica filled compounds were manufactured using the synthesized ESBR, and their mechanical properties, dynamic viscoelasticity, and crosslinking density were compared with those of the SBR/BR blended compound. When the content of butadiene was increased in the silica filled compound, the cure rate accelerated due to an increased number of allylic positions, which typically exhibit higher reactivity. However, the T-2 compound with increased butadiene content by synthesis less likely to show an increase in crosslink density due to poor silica dispersion. In addition, the T-3 compound containing high cis BR content showed high crosslink density due to its monosulfide crosslinking structure. Because of the phase separation, SBR/BR blend compounds were easily broken and showed similar $M_{100%}$ and $M_{300%}$ values as those of other compounds despite their high crosslink density. However, the developed blend showed excellent abrasion resistance due to the high cis-1,4 butadiene content and low rolling resistance due to the high crosslink density.

• 한국콘텐츠학회논문지
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• 제12권9호
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• pp.250-256
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• 2012

골밀도 감소에 의해서 발생되는 골감소증, 골다공증 등은 폐경 후 여성에게 유병률이 높은 질환이며, 골다공증 골절에 따른 사회적 의료비 상승으로 의학적 관심이 급증하고 있다. 신부전환자는 체내에 비타민D 합성 능력이 저하되어 칼슘 흡수가 감소하여 뼈의 섬유화가 발생되고, 골밀도가 감소하는 현상이 나타난다. 따라서 신부전환자는 신장 기능 장애로 그치지 않고, 골다공증과 같은 골밀도 감소에 따른 합병증에 노출되어 있다. 본 연구에서는 치료 중에 있는 신부전환자들의 골밀도 변화를 관찰하였고, 신장이식 전후에서 발견되는 골밀도 변화를 분석하였다. 조사대상은 부산 B종합병원 신장내과 내원환자 중 신부전환자 214명을 신장이식의 유무에 따라 골밀도의 변화를 세대별, 성별로 나누어 분석했다. 분석결과 신장이식 환자군에서는 골밀도가 유지되거나 개선되었지만, 비신장이식 환자군에서는 골밀도가 꾸준히 나빠지는 결과를 보였다. 신부전환자는 신장이식을 받는 것이 최선의 치료책으로 사료되며, 신장이식을 통해서 골밀도의 개선이 가능함을 확인하였다. 이는 추가적으로 예상되는 합병증을 예방하기 위한 자료로도 활용할 수 있다.