• Bulletin of the Korean Chemical Society
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• 제23권6호
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• pp.845-851
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• 2002

The synthesis of the intramolecular donor - stabilized silyl and germyl complexes of the type ($Cab^c.p) MMe_2X$ (2a:M=Si, X=Cl;2b;M= Ge, X=Cl;2e;M=Si,X=H) was achieved by the reaction of $LiCab^c,p$ (1) with $Me_2SiClX$ and $Me_2GeCl_2$ respectively. The intramolecular M←P interacion in 2a-2c is provided by $^1H$, $13^C.$, $31^P$ and $29^Si$ NMR spectroscopy. The salt elimination reactions of dichlorotetramethyldisilane and -digermane with 1 afforded the $bis(\sigma-carboranylphosphino)disilane$ and disgermane [$(Cab^C.P)MMe_2]_2(4a;M$ = Si;4b: M=Ge). The oxidative addition reaction of 4a-4b with $pd_2(dba)_3CHCl_3afforded$ the bis(silyl)-and bis(germyl)-palladium complexes. The chloro-bridged dipalladium complexes were obtained by the reaction of 2a-2b with $pd_2(dba)_3CHCl_3$ The crystal structures of 5a and 7b were determined by X-ray structural studies.

• Nutrition Research and Practice
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• 제7권2호
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• pp.89-95
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• 2013

Dietary inorganic sulfur is the minor component in our diet, but some studies suggested that inorganic sulfur is maybe effective to treat cancer related illness. Therefore, this study aims to examine the effects of inorganic sulfur on cell proliferation and gene expression in MDA-MB-231 human breast cancer cells. MDA-MB-231 cells were cultured the absence or presence of various concentrations (12.5, 25, or 50 ${\mu}mol/L$) of inorganic sulfur. Inorganic sulfur significantly decreased proliferation after 72 h of incubation (P < 0.05). The protein expression of $ErbB_2$ and its active form, $pErbB_2$, were significantly reduced at inorganic sulfur concentrations of 50 ${\mu}mol/L$ and greater than 25 ${\mu}mol/L$, respectively (P < 0.05). The mRNA expression of $ErbB_2$ was significantly reduced at an inorganic sulfur concentration of 50 ${\mu}mol/L$ (P < 0.05). The protein expression of $ErbB_3$ and its active form, $pErbB_3$, and the mRNA expression of $pErbB_3$ were significantly reduced at inorganic sulfur concentrations greater than 25 ${\mu}mol/L$ (P < 0.05). The protein and mRNA expression of Akt were significantly reduced at an inorganic sulfur concentration of 50 ${\mu}mol/L$ (P < 0.05), but pAkt was not affected by inorganic sulfur treatment. The protein and mRNA expression of Bax were significantly increased with the addition of inorganic sulfur concentration of 50 ${\mu}mol/L$ (P < 0.05). In conclusion, cell proliferation was suppressed by inorganic sulfur treatment through the ErbB-Akt pathway in MDA-MB-231 cells.

• Bulletin of the Korean Chemical Society
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• 제26권1호
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• pp.63-71
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• 2005

Equilibrium geometries, electronic structures, and energies of borocarbon clusters (binary compounds of carbon and boron), an unexplored class of molecules with highly unusual characteristics and potential for further development, have been investigated by means of B3LYP/6-311+G$^*$ density functional theory computations. A large number of B$_7$C${_1}^{1-}$, B$_6C_2$, and B$_5C_{3}\,^{1+}$ clusters with planar and non-planar monocyclic and polycyclic rings, as well as cage structures, have been systematically studied. Unexpectedly, planar forms are predicted not only to be the most stable structures, but also, in many cases, to have unprecedented planar heptacoordinate boron (p-heptaB) and planar heptacoordinate carbon (p-heptaC) arrangements. All these pheptaB and p-heptaC have 6π electrons and are aromatic according to the nucleus independent chemical shift (NICS). This novel bonding pattern is analyzed in terms of natural bond orbital (NBO) analysis. For virtually all possible B$_7$C${_1}^{1-}$, B$_6C_2$, and B$_5C_{3}\,^{1+}$ combinations, the p-heptaB arrangements are the more stable than other type structures.

• 한국영어학회지:영어학
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• 제3권3호
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• pp.427-452
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• 2003

Korean is famous for having all voiceless stop sounds. Korean does have voiced stops but they are considered to exist only as the allophones of word initial /p, t, k/. My experiment shows the English word initial stop sounds [b, d, g] and the Korean lax stop series /p, t, k/ in word initial position are similar in the range of voice onset time. If English word initial[b, d, g] sounds are posited as voiced, then Korean word initial /p, t, k/ should be classified as voiced also. Phonetically English /b, d, g/ phonemes and Korean /p, t, k/ phonemes are very similar except the word initial [p, t, k] are devoiced slightly more, but not significant enough to be classified as voiceless than English word initial [b, d, g]. If we posit /b, d, g/ as Korean phonemes, it explains why Korean /p, t, k/ series has the allophones [b, d, g] instead of fortis stops /p', t', k'/ in Korean even though /p', t', k'/ has less positive VOT value than /p, t, k/. If we posit /b, d, g/ as Korean phonemes, then it does not cause spelling or pronunciation confusion either when Koreans learn English or English speakers learn Korean.

• 호남수학학술지
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• 제31권3호
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• pp.437-449
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• 2009

In this paper, we calculate the number of points on elliptic curves $E^{a^3}_0:y^2=x^3+a^3$ over ${\mathbb{F}}_p$ mod 24 and $E^b_0:y^2=x^3+b$ over ${\mathbb{F}}_p$ mod 6, where b is cubic non-residue in ${\mathbb{F}}^*_p$. For example, if p ${\equiv}$ 1 (mod 12) is a prime, and a and a(2t - 3) are quadratic residues modulo p with $3t^2{\equiv}1$ (mod p), then the number of points in $E^{a^3}_0:y^2=x^3+a^3$ is congruent to 0 modulo 24.

• 디지털융복합연구
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• 제11권1호
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• pp.361-368
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• 2013

본 연구의 목적은 악성 및 양성 여성골반 병변에서 자기공명 확산강조영상의 정량적, 정성적평가을 통하여 최적의 확산경사계수(b-values) 값을 구하고, 임상적 유용성을 알아보고자 하였다. 확산강조영상의 b-value($s/mm^2$)값을 600, 800, 1000, 1200, 1400까지 변화시키면서 얻었다. 정량적 분석결과 b-values 값 중 800에서 자궁근종의 평균 신호대 잡음비 $84.6{\pm}4.57$(p=0.024) 와 대조도대 잡음비 $50.13{\pm}5.47$(p=0.028)로 가장 높았고, 자궁경부암의 평균 신호대 잡음비 $12.0{\pm}2.04$(p=0.047)와 대조도대 잡음비 $10.6{\pm}1.24$(p=0.001)로 가장 높았으며, 이때 현성확산계수는 자궁근종 $1.19{\times}10^{-3}$(p=0.008), 자궁경부암 $0.96{\times}10^{-3}$(p=0.027) 이었다. 정성적 분석결과로서 병변의 묘출도와 명확성은 $4.02{\pm}0.18$(p=0.028), $4.39{\pm}0.25$(p=0.015)로 800에서 가장 높았다. 결론적으로 확산강조 자기공명영상은 여성골반 병변 검출에 있어서 중요한 방법이고, 최적의 b-value($s/mm^2$)값은 $800s/mm^2$ 이었으며, 정량적, 정성적 평가는 여성골반의 악성 및 양성 감별진단에 도움을 주었다.

• Journal of Dental Anesthesia and Pain Medicine
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• 제24권2호
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• pp.91-99
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• 2024

Background: Palatal injections are often painful. We aimed to compare topical ice and 20% benzocaine gel for pre-injection anesthesia before greater palatine nerve block (GPNB) injections. Methods: A randomized split-mouth clinical trial was conducted among patients aged 15-60-years needing bilateral GPNB injections. A total of 120 palatal sites from 60 patients were randomly allocated to Group A (topical ice) or Group B (20% benzocaine gel). Pain was evaluated using sound, eye, motor (SEM), and the visual analog scale (VAS) in both groups. Inferential analysis was performed using the Mann-Whitney U test. Results: The mean age of the participants was 20.5 ± 3.9 years. The median VAS score for group A was 11 (Q1 - Q3: 5.25 - 21.75), which was slightly higher than the 10 (Q1 - Q3: 4.0 - 26.75) reported in group B. However, the difference was not statistically significant (P = 0.955). The median SEM score for group A and group B was 3.5 (Q1 - Q3: 3.0 - 4.0) and 4.0 (Q1 - Q3: 3.0 - 4.0), respectively, which was statistically insignificant (P = 0.869). Conclusion: Using ice as a form of topical anesthetic for achieving pre-injection anesthesia before GPNB was as effective as 20% benzocaine gel.

• 한국해양학회지
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• 제30권4호
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• pp.302-319
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• 1995

홀로세 후기 킹 죠지 섬 주변 해역의 고해양학적 변화와 기후 변화를 파악하기 위 하여 킹 죠지 섬 주변의 멕스 웰 만과 에드미럴티 만에서 채취한 2개의 해양 퇴적물의 지화학적 특성, 퇴적율 측정, 유공충의 분포 및 유공충의 각을 구성하고 있는 산소 및 탄소 동위원소비를 분석하였다. 유기탄소 함량은 대체로 시추 퇴적물의 하부층에서 상 부층으로 갈수록 증가하고, 탄산염 함량은 그 반대로 하부층으로 갈수록 증가하였다. 유공충은 총 27종이 감별되었으며, 비교적 우세한 종은 Globocassidurina bior이다. 유공충을 이용한 /SUP 14/C연대 측정치를 기준으로 계산한 퇴적율은 24 cm/kyr에서 237 cm/kyr 범위이나 상부층으로 갈수록 급격히 증가한다. 대표적 유공충인 G. biora 의 산소 및 탄소 동위원소비는 $\delta$/SUP 18/O 값의 경우 0.3$\textperthousand$에서 6.2$\textperthousand$ 범위이고 $\delta$ /SUP 18/C 값은 -0.3$\textperthousand$에서 0.0$\textperthousand$ 범위이다. 시추 퇴적물의 지절연대는 시추심 S-2의 최하부층인 깊이 128 cm에서 3,100$\pm$60 yr B.P이고, 시추심 S-19의 최하부층인 깊이 230 cm에서 7,460$\pm$70 yr B.P., 한랭 온난한 2,600~2,270 yr B.P 및 한랭 온난한 2,380~2,100 yr B.P의 5개 시기로 구분된다.

• Biomolecules & Therapeutics
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• 제31권3호
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• pp.330-339
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• 2023

Liver kinase B1 (LKB1) is a crucial tumor suppressor involved in various cellular processes, including embryonic development, tumor initiation and progression, cell adhesion, apoptosis, and metabolism. However, the precise mechanisms underlying its functions remain elusive. In this study, we demonstrate that LKB1 interacts directly with malic enzyme 3 (ME3) through the N-terminus of the enzyme and identified the binding regions necessary for this interaction. The binding activity was confirmed to promote the expression of ME3 in an LKB1-dependent manner and was also shown to induce apoptosis activity. Furthermore, LKB1 and ME3 overexpression upregulated the expression of tumour suppressor proteins (p53 and p21) and downregulated the expression of antiapoptotic proteins (nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and B-cell lymphoma 2 (Bcl-2)). Additionally, LKB1 and ME3 enhanced the transcription of p21 and p53 and inhibited the transcription of NF-κB. Moreover, LKB1 and ME3 suppressed the phosphorylation of various components of the phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B signaling pathway. Overall, these results suggest that LKB1 promotes pro-apoptotic activities by inducing ME3 expression.

• 한국발생생물학회지:발생과생식
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• 제15권3호
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• pp.223-230
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• 2011

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants derived from incomplete combustion of carbons and crude oil. In this study, we investigated the effects of benzo[a]pyrene (B[a]P), a representative PAHs on in vitro sex steroid hormone production and germinal vesicle breakdown (GVBD) using isolated oocytes of longchin goby (Chasmichthys dolichognathus) and chameleon goby (Tridentiger trigonocephalus). Oocytes in diameters of 0.8-0.9 (end vitellogenic stage) and 0.9-1.0 mm (germinal vesicle migratory stage) from longchin goby and 0.5 mm (fully vitellogenic stage) from chameleon goby were used. In GVBD assay, B[a]P at 10 nM stimulated GVBD in the oocytes of 0.8-0.9 mm from longchin goby. B[a]P at 1 nM stimulated GVBD in the oocytes with diameter 0.5 mm from chameleon goby. In steroid production from oocytes of longchin goby, B[a]P at 100 nM decreased testosterone (T) production, B[a]P at 1,000 nM increased estraiol-17 (J (E2) production and 10 and 100 nM increased $17,20{\beta}$-dihydroxy-4-pregnen-3-one ($17{\alpha}20{\beta}P$) production in the oocytes with diameter 0.8-0.9 mm. B[a]P at 1,000 nM increased E2 production, 100 and 1,000 nM increased $17{\alpha}20{\beta}P$ production in the oocytes with diameter 0.9-1.0 mm. In steroid production of oocytes from chameleon goby, B[a]P at 1,000 nM increased $E_2$ production. B[a]P at 10 nM increased $17{\alpha}20{\beta}P$ production. In the ratio of $E_2$ to T ($E_2$/T), B[a]P at 100 and 1,000 nM increased $E_2$/T in the oocytes of longchin goby. B[a]P at 100 nM also increased $E_2$/T in the oocytes of chameleon goby. Taken together, these results suggest that B[a]P have not only weak estrogenic effects but progestogenic effects on oocyte maturation.