• 한국재료학회지
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• 제20권11호
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• pp.606-610
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• 2010

Films consisting of a silicon quantum dot superlattice were fabricated by alternating deposition of silicon rich silicon nitride and $Si_3N_4$ layers using an rf magnetron co-sputtering system. In order to use the silicon quantum dot super lattice structure for third generation multi junction solar cell applications, it is important to control the dot size. Moreover, silicon quantum dots have to be in a regularly spaced array in the dielectric matrix material for in order to allow for effective carrier transport. In this study, therefore, we fabricated silicon quantum dot superlattice films under various conditions and investigated crystallization behavior of the silicon quantum dot super lattice structure. Fourier transform infrared spectroscopy (FTIR) spectra showed an increased intensity of the $840\;cm^{-1}$ peak with increasing annealing temperature due to the increase in the number of Si-N bonds. A more conspicuous characteristic of this process is the increased intensity of the $1100\;cm^{-1}$ peak. This peak was attributed to annealing induced reordering in the films that led to increased Si-$N_4$ bonding. X-ray photoelectron spectroscopy (XPS) analysis showed that peak position was shifted to higher bonding energy as silicon 2p bonding energy changed. This transition is related to the formation of silicon quantum dots. Transmission electron microscopy (TEM) and electron spin resonance (ESR) analysis also confirmed the formation of silicon quantum dots. This study revealed that post annealing at $1100^{\circ}C$ for at least one hour is necessary to precipitate the silicon quantum dots in the $SiN_x$ matrix.

• 폴리머
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• 제34권3호
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• pp.274-281
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• 2010

본 실험에서는 일련의 poly(ethylene glycol)-poly(D,L-lactide)(또는 -poly(D,L-lactide-co-glycolide))이중블록 공중합체들을 D,L-lactide(또는 glycolide)의 고리열림 중합에 의해 합성하고, 당뇨병 치료제 일종인 rosiglitazone의 가용화를 위한 고분자 미셀 제형으로서의 특성을 평가하였다. 고체분산법을 이용하여 높은 봉입률의 약물함유 미셀 제형을 효과적으로 제조하였고, 미셀 제형의 수용액 내 안정성을 hydrotropic agent의 일종인 2-hydroxy-N-picolylnitinamide(HPNA)의 사용으로 더욱 향상시킬 수 있었다. 생체 외 세포생존평가에서 생체적합성과 낮은 독성을 보였고, 쥐를 이용한 동물실험에서도 약물을 함유한 고분자 미셀이 약물 대조군보다 혈당을 보다 효과적으로 감소시켰다.

• 대한약리학회지
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• 제18권2호
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• pp.89-102
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• 1982

The $Na^+-and\;K^+-induced\;Ca^{++}$ release was measured isotopically by millipore filter technique in pig heart mitochondria. With EGTA-quenching technique, the characteristics of mitochondrial $Ca^{++}-pool$ and the sources of $Ca^{++}$ released from mitochondria by $Na^+\;or\;K^+$ were analyzed. The mitochondrial $Ca^{++}-pool$ could be distinctly divided into two components: internal and external ones which were represented either by uptake through inner membrane, or by energy independent passive binding to external surface of mitochondria, respectively. In energized mitochondria, a large portion of $Ca^{++}$was transported into internal pool with little external binding, while in de-enerigzed state, a large portion of transported $Ca^{++}$ existed in the external pool with limited amount of $Ca^{++}$ in the internal pool which was possibly transported through the $Ca^{++}-carrier$ present in the inner membrane. $Na^+$ induced the $Ca^{++}$ release from both internal pool and external pool and external binding pool of mitochondria. In contrast, $K^+$ did not affect $Ca^{++}$ of the internal pool, but, displaced $Ca^{++}$ bound to external surface of the mitochondria. When the $Ca^{++}-reuptake$ was blocked by EGTA, the $Ca^{++}$ release from the internal pool by $Na^+$ was rapid; the rate of $Ca^{++}-efflux$ appeared to be a function of $[Na^+]^2$ and about 8mM $Na^+$ was required to elicit half-maximal velocity of $Ca^{++}-efflux$. So it was revealed that $Ca^{++}-efflux$ velocity was particulary sensitive to small changes of the $Na^+$ concentration in physiological range. Energy independent $Ca^{++}-binding$ sites of mitochondrial external surface showed unique characteristics. The total number of external $Ca^{++}-binding$ sites of pig heart mitochondria was 29 nmoles per mg protein and the dissociation constant(Kd) was $34{\mu}M$. The $Ca^{++}-binding$ to the external sites seemed to be competitively inhibited by $Na^+\;and\;K^+$; the inhibition constant(Ki) were 9.7 mM and 7.1 mM respectively. Considering the intracellular ion concentrations and large proportion of $Ca^{++}$ uptake in energized mitochondria, the external $Ca^{++}-binding$ pool of the mitochondria did not seem to play a significant role on the regulation of intracellular free $Ca^{++}$ concentration. From this experiment, it was suggested that a small change of intracellular free $Na^+$ concentration might play a role on regulation of free $Ca^{++}$ concentration in cardiac cell by influencing $Ca^{++}-efflux$ from the internal pool of mitochondria.

• 한국콘텐츠학회논문지
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• 제9권11호
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• pp.262-270
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• 2009

세로토닌 수용체 5-$HT_{1A}$에 대한 방사성추적자로 알려진 $^{18}F$-mefway를 개선된 방법으로 합성하고, 소 동물 뇌 microPET 연구를 통해서 이 수용체에 선택적으로 결합하는 지를 확인하려고 한다. 기존 합성 방법을 수정하여 전구체를 합성하고, $[^{18}F]^-$과 $130^{\circ}C$에서 30분간 교반하여 $^{18}F$-mefway를 합성하여, Solid phase extraction(SPE)과 HPLC를 이용해 정제한 다음, 소동물 뇌의 microPET 다이나믹 영상을 얻었다. Oxalyl chloride와 LAH/diethyl ether을 사용해서 기존 합성수율 9%에서 34%로 $^{18}F$-mefway 전구체를 향상된 수율로 합성할 수 있는 개선된 방법을 확립하였다. 이렇게 합성된 $^{18}F$-mefway는 세로토닌 5-$HT_{1A}$수용체 영상용 방사성 의약품으로서 신경정신질환 연구에 이용될 수 있을 것으로 사료된다.

• 한국결정성장학회지
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• 제12권4호
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• pp.202-209
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• 2002

$CuInSe_2$ 단결정 박막은 수평 전기로에서 합성한 다결정을 증발원으로 하여, hot wall epitaxy(HWE) 방법으로 증발원과 기판(반절연-GaAs(100))의 온도를 각각 $620^{\circ}C$, $410^{\circ}C$로 고정하여 단결정 박막을 성장하였다. 단결정 박막의 결정성은 광발광과 이중결정 X-선 요동곡선(DCRC)으로 연구하였다. $CuInSe_2$ 단결정 박막의 운반자 농도와 이동도는 van der Pauw 방법으로 측정되었다. 또한 $CuInSe_2$ 단결정 박막의 C축에 수직하게 빛을 쬐었을 때 측정되여진 단파장대의 광전류 봉우리 갈라짐으로부터 결정장 갈라짐 $\Delta$Cr과 스핀 궤도 갈라짐 $\Delta$So(spin orbit splitting) 값을 구하였다. 광발광 측정으로부터 고품질의 결정에서 볼 수 있는 free exciton($E_x$)와 매우 강한 세기의 중성 받게 bound exciton($A^{\circ}$, X) 피크가 관찰되었다. 이때 중성 받게 bound exciton의 반치폭과 결합 에너지는 각각 7meV와 5.9meV였다. 또한 Haynes nile에 의해 구한 불순물의 활성화 에너지는 59meV였다.

• Journal of Periodontal and Implant Science
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• 제26권4호
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• pp.889-905
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• 1996

It is known that growth factors function as potent biologic mediators regulating numerous activities of wound healing via cell proliferation, migration and extracellular matrix formation and they also promote periodontal regeneration. But, method of growth factor application is controversial yet. So purpose of this study is to evaluate the effect of demineralized root surface as one of method of growth factor application. The ginigival fibroblasts were primary cultured and fifth or sixth subpassages were used in these experiments. In first experiment, root surface blocks demineralized with 100mg/ml tetracycline for 5 minutes and pH 1 citric acid for 3 minutes(experimental groups) and nonteminerilized root surface blocks (control groups) were placed in 100ng/ml PDGF-BB for 5 minutes. Then the cells were seeded on each root surface blocks and cultured for 6, 24, 48, 72 hours. In second experiment, root surface blocks deminerilized with tetracycline and citric acid and nondemineralized root surface blocks were placed in 200ng/ml PDGF-BB for 5 minutes and another non-demineralized root surfcae blocks were placed in DMEM without PDGF-BB. At 1, 2, 4, 6, 8 days, the cells were seeded in 24-well plate and using of each eluent, cultured for 72 hours. The results of the four determinants were presented as mean and S.D.. The results were as follows : The attachment and proliferation of human gingival fibroblast on root surface were more increased when PDGF-BB was applicated on root surfrace demineralized with tetracycline or citric acid than non-demineralized root surface. And, in comparision tetracycline with citric acid, there were more attachment and proliferation of human gingival fibroblast on root surface demineralized with tetracycline than citric acid, and proliferation of human gingival fibroblast on demineralized root surface was increased time dependently 1 day to 3 days. In second experiment using eluent, proliferation of human gingival fibroblast was more increased to 6 days when human gingival fibroblast was cultured in eluent that PDGF-BB was applicated on demineralized root surface than two control groups, and degree of proliferation was decreased time dependently 1 day to 6 days. Proliferation of human gingival fibroblast cultured in eluent without PDGF-BB was constant 1 day to 6 days. After 6 days, degree of proliferation of human gingival fibroblast was similar in four groups. This means that release duration of PDGF-BB from demineralized root surface is 6 days. And in comparision tetracycline with citric acid, there was more proliferation of human gingival fibroblast in tetracycline-treated group than citric acid. In conclusion, demineralized root surface as primary site for PDGF-BB application, especially demineralized with tetracycline has important roles in attachment and proliferation of human gingival fibroblast, and may be useful clinical applications in periodontal regenerative procedures.

• BMB Reports
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• 제39권5호
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• pp.642-647
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• 2006

Botulinum neurotoxin A (BoNT/A) has been used therapeutically to treat muscular hypercontractions and sudomotor hyperactivity and it has been reported that BoNT/A might have analgesic properties in headache. PEP-1 peptide is a known carrier peptide that delivers fulll-ength native proteins in vitro and in vivo. In this study, a BoNT/A gene were fused with PEP-1 peptide in a bacterial expression vector to produce a genetic in-frame PEP-1-BoNT/A fusion protein. The expressed and purified PEP-1-BoNT/A fusion proteins were efficiently transduced into cells in a time- and dose-dependent manner when added exogenously in a culture medium. In addition, immuno-histochemical analysis revealed that PEP-1-BoNT/A fusion protein efficiently penetrated into the epidermis as well as the dermis of the subcutaneous layer, when sprayed on mice skin. These results suggest that PEP-1-BoNT/A fusion protein provide an efficient strategy for therapeutic delivery in various human diseases related to this protein.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2001년도 추계학술대회 및 정기총회
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• pp.102-102
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• 2001

Taurine (2-ethaneaminosulfonic acid) is one of the major intracellular ${\beta}$ -amino acids in mammals and is required for a number of biological processes including membrane stabilization, osmoregulation, antioxidation, detoxification, modulation of calcium flux and neurornodulation. The taurine transporter (TAUT) which contains 12 hydrophobic membrane-spanning domains has been cloned from dog kidney, rat brain, mouse brain, human thyroid, placenta and retina. In this study, The TAUT cDNA from the human intestinal epithelial cell, HT-29 was cloned and sequenced. Reverse-transcription polymerase chain reaction (RT-PCR) was performed to amplify partial cDNA encoding human intestinal TAUT. The coding region of the PCR product was 732 bp long. The primers were designed to encode highly conserved amino acid sequences near the transmembrane domains III (IPYFIFLF) and Ⅵ (KYKYNSYR) both in human and mouse. The TAUT cDNA amplified was ligated into the pGEX 4T-1 expression vector. The resulting sequence of human intestinal TAUT cDNA (Accession number of NCBI Genebank is AF346763) was identical to the sequences of the TAUTs previously determined in the human placenta and retina except 3 base pairs from that of the reported human thyroid. TAUT specific antibodies were generated to use them as biological tools in the studies of the biological role of TAUT. Peptides of 149-162 amino acid residue (14 amino acids) of the TAUT were synthesized. The synthetic peptide used in this study was LFQSFQKELPWAHC. This region was chosen not only to avoid putative glycosylation sites but also to exclude regions of known homology with GABA transporters in the extracellular hydrophilic domains. The synthetic peptide, TAUT-1 was conjugated with carrier protein, kehole lympet hemocyanin (KLH) to use as an antigen. When used for immunization on a rabbit to produce polyclonal antiserum, the conjugates elicited high -titered specific anti-TAUT-1 antibodies, which reacted well with the ovalbumin (OVA) conjugated peptides in ELISA. The KLH-conjugated peptide was also used as immunizing antigen in BALB/c mice to produce TAUT specific monoclonal antibodies. From the culture supernatant of the hybridoma, the specificity of anti-TAUT-1 monoclonal antibodies was confirmed by ELISA. Further applications of more tools in TAUT expression analysis will be performed such as western blotting and flow cytometry.

• 환경생물
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• 제21권2호
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• pp.189-193
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• 2003

본 연구는 여자 축구선수 25명을 대상으로 혈중 지질성분과 철분지표를 조사 .분석하고, 훈련기 동안의 철분보충이 혈청 지질과 지단백 콜레스테롤에 미치는 영향을 살펴보았다. 여자축구선수들의 평균연령은 23.3$\pm$2.5세였고, 평균 신장과 체중은 각각 164.4$\pm$5.7cm과 57.4$\pm$4.6kg이었고, 체지방율은 23.9$\pm$3.0%였다. 혈액 철분지표 분석결과 평균 적혈구 용적, 헤모글로빈, 총철결합력은 정상범위 내에 있었으나 낮은 수준이었으며, 특히 평균 페리틴 (ferritin) 농도는 18.7$\pm$ 19.7 ${\mu}g$ $1^{-1}$로 낮았다. 혈청 지질과 지단백 분석 결과, 중성지질은 81.7$\pm$26.3mg $dl^{-1}$로 정상이나, 총 콜레스테롤과 LDL 콜레스테롤은 224.3$\pm$58.3 mg $dl^{-1}$과 162.2$\pm$59.0 mg $dl^{-1}$으로 높게 나타났다 상관관계 분서 결과 운동선수들의 적혈구 세포수가 많을수록 중성지질 농도가 낮고, 평균 적혈구 용적이 클수록 HDL-콜레스테롤 농도가 높아서 선수들의 철분 상태가 바람직할수록 혈액 지질 상태가 바람직한 것으로 나타났다. 한편, 철분 보충 여부는 혈청 지질 상태에 영향을 미치지 않았고,4주간 하계 훈련은 철분 투여에 관계없이 혈청 중성지방과 콜레스테롤을 낮추는 경향으로 나타났다. 결론적으로 여자 프로 축구 선수들의 혈청 굴성지질은 정상 범위 내에 속했으나, 콜레스테롤, 특히 LDL-콜레스테롤 수준이 정상보다 높았으며, 단기간의 철분 보충은 혈청 지질과 지단백 콜레스테롤에 큰 영향을 미치지 않았다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권8호
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• pp.3471-3476
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• 2014

Background: Aberrant expression of the microRNA-29 family is associated with tumorigenesis and cancer progression. As transport carriers, tumor-derived exosomes are released into the extracellular space and regulate multiple functions of target cells. Thus, we assessed the possibility that exosomes could transport microRNA-29c as a carrier and correlations between microRNA-29c and apoptosis of bladder cancer cells. Materials and Methods: A total of 28 cancer and adjacent tissues were examined by immunohistochemistry to detect BCL-2 and MCL-1 expression. Disease was Ta-T1 in 12 patients, T2-T4 in 16, grade 1 in 8, 2 in 8 and 3 in 12. The expression of microRNA-29c in cancer tissues was detected by quantitative reverse transcriptase PCR (QRT-PCR). An adenovirus containing microRNA-29c was used to infect the BIU-87 human bladder cancer cell line. MicroRNA-29c in exosomes was measured by QRT-PCR. After BIU-87 cells were induced by exosomes-derived microRNA-29c, QRT-PCR was used to detect the level of microRNA-29c. Apoptosis was examined by flow cytometry and BCL-2 and MCL-1 mRNA expressions were assessed by reverse transcription-polymerase chain reaction. Western blotting was used to determine the protein expression of BCL-2 and MCL-1. Results: The expressions of BCL-2 and MCL-1 protein were remarkably increased in bladder carcinoma (p<0.05), but was found mainly in the basal and suprabasal layers in adjacent tissues. The expression of microRNA-29c in cancer tissues was negatively correlated with the BCL-2 and MCL-1. The expression level of microRNA-29c in exosomes and BIU-87 cells from the experiment group was higher than that in control groups (p<0.05). Exosome-derived microRNA-29c induced apoptosis (p<0.01). Although only BCL-2 was reduced at the mRNA level, both BCL-2 and MCL-1 were reduced at the protein level. Conclusions: Human bladder cancer cells infected by microRNA-29c adenovirus can transport microRNA-29c via exosomes. Moreover, exosome-derived microRNA29c induces apoptosis in bladder cancer cells by down-regulating BCL-2 and MCL-1.