Stimuli-responsive biomaterials that alter their function through sensing local molecular cues may enable technological advances in the fields of drug delivery, gene delivery, actuators, biosensors, and tissue engineering. In this research, pH-responsive hydrogel which is comprised of dimethylaminoethyl methacylate (DMAEMA) and 2-hydroxyethyl methacrylate (HEMA) was synthesized for the effective delivery of doxorubicin (Dox) to breast cancer cells. Cancer and tumor tissues show a lower extracellular pH than normal tissues. DMAEMA/HEMA hydrogels showed significant sensitivity by small pH changes and each formulation of hydrogels was examined by scanning electron microscopy, mechanical test, equilibrium mass swelling, controlled Dox release, and cytotoxicity. High swelling ratios and Dox release were obtained at low pH buffer condition, low cross-linker concentration, and high content of DMAEMA. Dox release was accelerated to 67.3% at pH 5.5 for 6-h incubation at 37oC, while it was limited to 13.8% at pH7.4 at the same time and temperature. Cell toxicity results to breast cancer cells indicate that pH-responsive DMAEMA/HEMA hydrogels may be used as an efficient matrix for anti-cancer drug delivery with various transporting manners. Also, pH-responsive DMAEMA/HEMA hydrogels may be useful in therapeutic treatment which is required a triggered release at low pH range such as gene delivery, ischemia, and diabetic ketoacidosis.

In this study, poly(amic acid) was prepared via a polycondensation reaction of 3,3'-dihydroxybenzidine and pyromellitic dianhydride in an N-methyl-2-pyrrolidone solution; reduced graphene oxide/polybenzoxazole (r-GO/PBO) composite films, which significantly increased the electrical conductivity, were successfully fabricated. GO was prepared from graphite using Brodie's method. The GO was used as nanofillers for the preparation of r-GO/PBO composites through an in situ polymerization. The addition of 50 wt% GO led to a significant increase in the electrical conductivity of the composite films by more than sixteen orders of magnitude compared with that of pure PBO films as a result of the electrical percolation networks in the r-GO during the thermal treatment at various temperatures within the films.

In this study, we used flow a cytometric assay to evaluate plasma membrane integrity and mitochondrial activity in post-thawed sperm that was supplemented with ginsenoside-Rg1. Varying concentrations of ginsenoside-Rg1 (0, 25, 50 and 100 μM/ml) were used in the extender during cryopreservation to protect the DNA of thawed sperm, thereby increasing the viability and motility rate as evaluated using a computer-assisted sperm analysis (CASA) method. The results derived from CASA were used to compare the fresh, control, and ginsenoside-Rg1 groups. Sperm motility and the number of progressively motile sperm were significantly (p<0.05) higher in the 50 μM/ml ginsenoside-Rg1 group (61.0±4.65%) than in the control (46.6±7.02%), 25 μM/ml (46.2±4.76%), and 100 μM/ml ginsenoside-Rg1 (52.0± 1.90%) groups. However, the velocity distribution of post-thawed sperm did not differ significantly. Membrane integrity and MMP staining as revealed using flow cytometry were significantly (p<0.05) higher (91.6±0.82%) in the 50 μM/ml ginsenoside-Rg1 group than in the other groups. Here, we report that ginsenoside-Rg1 affects the motility and viability of boar spermatozoa. Moreover, ginsenoside- Rg1 can be used as a protective additive for the suppression of intracellular mitochondrial oxidative stress caused by cryopreservation.

전해정련을 이용한 폐 피복관 처리의 타당성을 살펴보기 위하여, 500℃의 LiCl-KCl 용융염 내에서 표면이 산화된 10 g 규모의Zircaloy-4 피복관 및 순수한 Zircaloy-4 피복관의 전기화학적 거동을 살펴보았다. 산화된 Zircaloy-4 피복관이 담긴 basket을 작업전극으로하여 전압-전류 관계를 측정한 결과, 산화되지 않은 Zircaloy-4 피복관과 비교해 Zr의 산화 peak는 Ag/AgCl 기준전극 대비, 약 -0.7 V ~ -0.8 V로 유사한 반면, 산화 전류의 크기는 확연하게 감소하는 것으로 나타난다. 이러한 결과는 -0.78V의 일정전위를 가한 전기화학적 용해 실험에서 살펴본 전류-시간 곡선에서도 유사하게 나타나며, 피복관 조각들의 평균 두께 및 무게 변화로부터 확인할 수 있다. Zircaloy-4 피복관이 산화되었을 경우, 표면의 산화막이 피복관의 전도성에 영향을 주어 basket 내 위치에 따라 전기화학적 용해의 균일성 및 속도를 떨어뜨리는 것으로 나타나지만, 표면의 미세한 결함과 Zr 산화물의 상 특성으로 인해 전기화학적 용해가 진행되는 것으로 판단된다.

A new model and resultant equation for the coagulation of acrylonitrile monomers in precipitation polymerization are suggested in consideration of the surface tension (γ) and cohesive energy density (ECED). The equation was proven to be quite favorable by considering figure fittings from known surface tensions and cohesive energy densities of certain organic solvents. The relationship between scale value of surface tension (γ/M) and cohesive energy density of monomers can be obtained by changing the coagulation bath component for effective precipitation polymerization of acrylonitrile in wet spinning.

Retinoic acid plays an important role in the regulation of cell growth and differentiation. In our present study, we evaluated the effects of all-trans retinoic acid (RA) on cell proliferation and on the cell cycle regulation of human gingival fibroblasts (HGFs). Cell proliferation was assessed using the MTT assay. Cell cycle analysis was performed by flow cytometry, and cell cycle regulatory proteins were determined by western blot. Cell proliferation was increased in the presence of a 0.1 nM to 1μM RA dose range, and maximal growth stimulation was observed in cells exposed to 1 nM of RA. Exposure of HGFs to 1 nM of RA resulted in an augmented cell cycle progression. To elucidate the molecular mechanisms underlying cell cycle regulation by RA, we measured the intracellular levels of major cell cycle regulatory proteins. The levels of cyclin E and cyclin-dependent kinase (CDK) 2 were found to be increased in HGFs following 1 nM of RA treatment. However, the levels of cyclin D, CDK 4, and CDK 6 were unchanged under these conditions. Also after exposure to 1 nM of RA, the protein levels of p21 WAF1/CIP1 and p16 INK4A were decreased in HGFs compared with the control group, but the levels of p53 and pRb were similar between treated and untreated cells. These results suggest that RA increases cell proliferation and cell cycle progression in HGFs via increased cellular levels of cyclin E and CDK 2, and decreased cellular levels of p21 WAF1/CIP1 and p16 INK4A.

The aim of this study was to determine the immediate effects of single treatment of strain-counter strain (SCS) on pressure pain threshold (PPT) and muscle activity during scapular plane abduction with 3% body weight load. Fifteen asymptomatic male adults with upper trapezius latent trigger point (LTrP) (PPT<2.9 ) participated in this study. Pressure algometer was used to measure PPT and surface electromyography was used to record upper, middle arid lower trapezius, serratus anterior, infraspinatus and middle deltoid muscle activity and relative ratio during scapular plane abduction between pre- and post-intervention. There was a significant increase in upper trapezius PPT after a 90-second SCS (p<.05). The activity of the upper trapezius and middle deltoid was significantly decreased (p=.014, p=.001), coupled with a decreased muscle activity ratio between the upper and lower trapezius (p<.05). These results indicate that the SCS may effectively deactivate upper trapezius activity, thereby alleviating muscle balance and reducing pain sensitivity.

This study has been conducted on the subjects of eight undergradu˗ ate students with abdominal obesity and eight undergraduate stu˗ dents with normal weight to find out correlation between substantial fatigue and Ratings of perceived exertion through analysis of their blood components when they took exercises to strengthen their abdominal muscular power. Comparatively analyzing HDL-C, LDL-C and lactic acid before and after they took sit-up at level of RPE 19-20, no statistically significant differences in HDL, LDL, lactic acid meas˗ ures were observed between groups, but a significant difference in RPE was noted between groups(p<0.05) Our findings suggest that control group showed no significant differ˗ ence in increase of fatigue material whereas the obese group showed a lower frequency of sit-up, though both groups took the same abdominal exercise. Additionally, the lower frequency of sit-up in obese group results from relatively higher Ratings of perceived exer˗ tion rather than increase of substantial fatigue material. This study invites future research that examines the effect of a comprehensive obesity exercise program combined with dietetic

Insensitive acetylcholinesterase (AChE) was determined to be basically involved in a EPN-resistant (ER) strain and ER contaminated susceptible (CS) strain of diamondback moth (DBM, Plutella xylostella L.), as estimated by the AChE inhibition assay using DDVP as a inhibitor in nondenaturing electrophoresis gel. ER strain exhibited very high insensitivity revel, high resistance ratio and two point mutations (G227A, A201S) in ace1. CS strain showed intermediate insensitivity level, low resistance ratio and a point mutation (G227A). This finding suggests that the A201S mutation along with reported G227A mutation (Baek et al, 2005) can be main player to develop the organophosphate resistance. Additionally, surveyed seven local population DBMs saturated G227A mutation and A201S mutation mixed in some population. Also A441G mutation was detected in some population, but there was no significant correlation. These results suggest that A201S mutation could be one of the good candidate for molecular diagnosis marker of resistance monitoring.

Insensitive acetylcholinesterase (AChE) was determined to be basically involved in a EPN-resistant (ER) strain of diamondback moth (DBM, Plutella xylostella L.), as estimated by the AChE inhibition assay using DDVP and thiodicarb as inhibitors in nondenaturing electrophoresis gel. AChEs were clearly separated into four different bands (a major band and three minor bands) in susceptible strain (CS) and all bands inhibited by used inhibitors almost same level, however, only two bands (a major band and a minor band) showed in that of ER strain and major band showed higher insensitivity. Moreover, ER strain showed cross resistance against used inhibitors and DDVP highly inhibited esterase in both strains. About 2kb of ace1,2 cloned and point mutations were detected in ER strain.

Wnt genes encode a large fami ly of secreted cysteine-rich signaling mol ecules involved in cell growth‘ differentiation and tumorigenesis, Wnt5a, a non-transforming member of the Wnt fa mily behaves as a putative onco 一 gene in many cancers including melanomas, The aim of our study was to determine Wnt5a ex pression pattern in pnmalγ oral mucosal melanomas(Ol\αÆ) and correlate it with tumor thlckness Archival ti ssues from 18 OMM cases were subjected to immunohistochemical detection of Wnt5a by the streptavidin-biotin method , These were categorized into tumors of (4 mm(thin and intermediate thickness lesions) and )4 mm(t hi ck lesions) t hickness, Most OMM cases(17/18; 94, 4%) stained positive for Wnt5a, though heterogeneously, Seven t hi ck(7/11: 64%) and one in termediate thickness(1/7‘ 14%) ol\α‘ demonstrated strongly positive Wnt5a staining(P(O, 05), The only Wnt5a-neg ative case was a thi ck OMM without local recurrence after treatment Strong Wnt5a express ion at tumor adva ncing sites suggests a role in local tumor spread, Identification of pleomorphi c epitheli oid and spindle cells as mel anoma cell populations with the most pronounced Wnt5a staining suggests that Wnt5a overexpression inJ] uences cellular phenotype, These results taken together suggest that Wnt5a is up- regulated in OMM a nd may play a role in tumor progression, Wnt5a activity is most frequently detected in advanced OMM suggesting its function in tumor progression, Expression level of Wnt5a in OMM correlated with tumor grade and t hickness

The shrinkage variation of Low Temperature Cofired Ceramics(LTCC) limits the size of the substrates that impose limitations on embedded passive components. This paper focuses on the method of minimizing or controlling planar shrinkage and reducing distortion during firing. The laminated sheets of alumina and glass were sintered at varying temperature, and depending on the amount of the glass ceramics. When the sintered of multi-layer structure with , the glass infiltrated entirely into layer at the temperature of about or higher.

Ni-doped was prepared by the encapsulated induction melting and hot pressing, and its doping effects on the thermoelectric properties were investigated. Single phase was successfully obtained by the subsequent heat treatment at 773K for 24 hours. Nickel atoms acted as electron donors by substituting cobalt atoms. Thermoelectric properties were remarkably improved by the appropriate doping.

The encapsulated induction melting and hot pressing were employed to prepare Fe-doped skutterudites and their thermoelectric properties were investigated. Single phase was successfully obtained by the subsequent heat treatment at 773K for 24 hours. Iron atoms acted as electron acceptors by substituting cobalt atoms. Thermoelectric properties were remarkably improved by the appropriate doping. was found as an optimum composition for best thermoelectric properties in this work.

Falls are common, costly, and a leading cause of death among older adults. The major predisposing factors of a fall may include age-related deterioration in the dynamic system composed of auditory, somatosensory, vestibular, visual, musculoskeletal, and neuromuscular subsystems. Older adults with a history of frequent falls demonstrated significant reductions in gait velocity, muscle force production, and balance performance. These altered neuromechanical characteristics may be further exaggerated when faced with conflicting multisensory conditions. Despite the important contribution of multisensory function on the sensorimotor system during postural and locomotor tasks, it remains unclear whether multisensory intervention will produce dynamic balance improvement during locomotion in older adults with a history of frequent falls. Therefore, the purpose of this paper is to address important factors associated with falls in elderly adults and provide theoretical rationale for a multisensory intervention program model.

사용후핵연료의 효율적인 관리를 위하여 원자력연구소에서 개발중인 사용후핵연료 차세대관리 종합공정(ACP)은 공정타당성연구 단계를 마치고 이의 실증을 위한 - type핫셀 건설 단계에 이르렀다. 핫셀의 설계에 앞서 사용후핵 연료를 취급하게 되는 과정에서 발생할 수 있는 방사능에 대한 환경영향평가를 정상운전 시와 사고발생 시로 나누어 수행하였다. 평가에 필요한 자료들은 공정의 개념설계 보고서와 최근 연구소부지 기상 테이터 및 부지특성 자료를 바탕으로 하였으며 기존의 유사한 시설에 대한 평가방법을 참조하였다. 각 핵종별 발생량과 방출량을 계산하여 피폭선량을 계산하였으며 평가결과 원자력법관련 규제기준과 핫셀이 위치하게 되는 IMEF 건물의 안전성분석 기준보다 매우 안전한 결과를 얻어 시설 운영에 대한 안전성을 확보하였다.