• Restorative Dentistry and Endodontics
• /
• 제46권3호
• /
• pp.41.1-41.23
• /
• 2021

Objectives: This study aimed to evaluate the efficacy of various local anesthesia (LA) in vital asymptomatic teeth. Materials and Methods: Randomized controlled trials comparing pulpal anesthesia of various LA on vital asymptomatic teeth were included in this review. Searches were conducted in the Cochrane CENTRAL, MEDLINE (via PubMed), EMBASE, ClinicalTrials.gov, Google Scholar and 3 field-specific journals from inception to May 3, 2019. Study selection, data extraction, and risk of bias assessment using Cochrane Risk of Bias Tool were done by 2 independent reviewers in duplicate. Network meta-analysis (NMA) was performed within the frequentist setting using STATA 15.0. The LA was ranked, and the surface under the cumulative ranking (SUCRA) line was plotted. The confidence of the NMA estimates was assessed using the CINeMA web application. Results: The literature search yielded 1,678 potentially eligible reports, but only 42 were included in this review. For maxillary buccal infiltration, articaine 4% with epinephrine 1:100,000 was more efficacious than lidocaine 2% with epinephrine 1:100,000 (odds ratio, 2.11; 95% confidence interval, 1.14-3.89). For mandibular buccal infiltration, articaine 4% with epinephrine 1:100,000 was more efficacious than various lidocaine solutions. The SUCRA ranking was highest for articaine 4% with epinephrine when used as maxillary and mandibular buccal infiltrations, and lidocaine 2% with epinephrine 1:80,000 when used as inferior alveolar nerve block. Inconsistency and imprecision were detected in some of the NMA estimates. Conclusions: Articaine 4% with epinephrine is superior when maxillary or mandibular infiltration is required in vital asymptomatic teeth.

• Journal of Positioning, Navigation, and Timing
• /
• 제11권1호
• /
• pp.1-9
• /
• 2022

Global Navigation Satellite System (GNSS) provides location information using signals from multiple satellites. However, a spoofing attack that forges signals or retransmits delayed signals may cause errors in the location information. To prevent such attacks, authentication protocols considering the navigation message structure of each GNSS can be used. In this paper, we analyze the authentication protocols of Global Positioning System (GPS), Galileo, and BeiDou, and compare the performance of Navigation Message Authentication (NMA) of the above systems, using several performance indicators. According to our analysis, authentication protocols are similar in terms of performing NMA and using Elliptic Curve Digital Signature Algorithm (ECDSA). On the other hand, they are different in several ways, for example, whether to perform Spreading Code Authentication (SCA), whether to use digital certificates and whether to use Timed Efficient Stream Loss-tolerant Authentication (TESLA). According to our quantitative analysis, the authentication protocol of Galileo has the shortest time between authentications and time to first authenticated fix. We also show that the larger the sum of the navigation message bits and authentication bits, the more severely affected are the time between authentications and the time to first authenticated fix.

• 대한치과교정학회지
• /
• 제25권6호
• /
• pp.715-722
• /
• 1995

Orthodontic tooth movement in response to orthodontic force results from actions of osteoclasts and osteeoblasts in the cell level. Convincing evidence has now been provided to support the view that osteoclasts are derived from mononuclear cells that originate in the bone marrow or other hematopoietic organs and they migrate to the bones via vascular routes. Nitric oxide(NO), which accounts for the biological properties of endothelium-derived relaxing factor(EDRF), is the endogenous stimulator of soluble guanylate cylase. The discovery of the formation of nitric oxide(NO) from L-arginine in mammalian tissues and its biological roles has, in the last 7 years, thrown new light onto many areas of research. Data from experiments in vitro showed that N-metyl-L-arginine(L-NMA) and L-nitro-L- arginine(L-NAME) are competitive inhibitors of nitric oxide synthase. This study suggest that the multinucleated cells in our culture have characteristics of osteoclasts and that the potential bone cell activity of nitric oxide in vitro may be mediated in part by stimulation of marrow mononuclear cells to form osteoclast-like cells. Bone marrow cells were obtaineed from tibia of 19-days old chick embryo. After sacrifice, tibia was quickly dissected and the bone were then split to expose the medullary bone. The cells were attached for 4 hours and the nonadherent cells were collected. Marrow cells weere cultured in 96-well plate in medium 199. To examine the number of TRAP-positive multinucleated cells(MNCs), $10^{-8}\;M\;Vit=D_3$ and various concentration of L-NMA and L-NAME weere added at the beginning of cultures and with each medium change. After 7 days of culture. tartrate-resistant acid phosphatase(TRAP) staining was performed for microscopic evaluation. Cells haying more than three nuclei per cell were counted as MNCs. The obsrved results were as follows;1. 1,25-dihydroxyvitamine $D_3$ stimulated the osteoclast-like multinucleated cells in cultures of chick embryo bone marrow. 2. Nitric oxide synthase inhibitors(NOSI ; N-NMA, N-NAME) stimulated the osteoclast-like cells in cultures of chick embry bone marrow. 3. 1,25-dihydroxyvitamine$D_3$ and nitric oxide synthase inhibitors did not appear to have additive effect on the generation of TRAP-positive MNCs. These results suggest that nitric oxide synthase inhibitors may stimulate the osteoclast-like multinucleated cell formation and fusion in cultures of chick bone marrow.

• 생명과학회지
• /
• 제24권10호
• /
• pp.1137-1143
• /
• 2014

Doxorubicin은 광범위한 암을 치료하는데 사용되는 일반적인 항암제이지만, 내인성 산화질소 생성량과 Doxorubicin의 항암 효과의 상관 관계에 대해서는 아직 명확하게 밝혀지지 않았다. 본 연구에서는 인간 대장암 세포에서 Doxorubicin의 항암 활성에 내인성 산화질소가 미치는 영향을 확인하고자 하였다. HCT116 (p53-WT)과 HT29 (p53-MUT) 세포에서 Doxorubicin 처리에 의해 세포 생존율의 차이를 보였으며, NMA 병행처리는 Doxorubicin의 효과를 감소시켰음을 확인할 수 있었다. 추가 연구를 통해 HCT116과 HT29 세포에서 sub-$G_1$ 기의 세포 빈도와 DNA 단편화의 결과를 통해 내인성 산화질소가 Doxorubicin에 의한 apoptosis를 조절하는 것을 확인하였다. 이러한 결과는 인간 대장암 세포에서 내인성 산화질소와 IAP 발현, p53의 상태에 따른 조절이 Doxorubicin에 의해 유도된다는 것을 보여주며, 이러한 메커니즘은 대장암에서 화학요법의 효율을 향상시키기 위한 전략적인 표적으로 이용할 수 있을 것으로 생각된다.

• Journal of Periodontal and Implant Science
• /
• 제27권4호
• /
• pp.883-908
• /
• 1997

Bone remodeling is characterized by the coupling of osteoclast-mediated bone resorption and osteoblast-mediated bone formation. The process is tightly regualted at the local level by an incompletely known netwotk of peptide and non-peptide fators. Nitric oxide(NO), synthesized by nitric oxide synthetase(NOS) from L-arginine, is becoming recognized as an important bioregualtory molecule in a variety of tissue, but little is known about its possible role in periodontal tissue. The purpose of this study is to investigate the expression of nitric oxide synthetase(NOS) in inflamed gingiva and the effects of cytokine on the expression of NOS protein. The expression of NOS in gingival tissue was evaluated by immunohistochemical staining for $NOS_1$, $NOS_2$, $NOS_3$. The effect of cytokine on the expression of NOS in human periodontal ligament cells and osteoblast-like HOS cells by western blot analysis. Further, we studied that NO functions in periodontal ligament cells as a regulatory molecule. PDL cells incubated with NOS inhibitor and donor. The protein expression, type I collagen & non-collagenous protein, nitrate production and cell proliferation were evaluated The results were as follows. 1. $NOS_1$, $NOS_2$, $NOS_3$ was rarely distributed in healthy gingiva, but stronger stained in gingival epithelium, endothelial cells, and mononuclear cells of inflammed gingiva. 2. The cytokine stimulated $NOS_1$, and $NOS_3$ protein were not inducing or inhibitory effect to compared with control in PDL and HOS cells. 3.Incubation of cells with combination of $TNF-{\alpha}$, $IFN-{\gamma}$, LPS result in a time dependant increase in $NOS_2$ expression, reaching a maximal level after 24 hours of stimulation. 4. The osteonectin protein inhibitory effect of NMA, inhibitor of NOS, was reversed by Larginine in dose dependant manner. 5. NMA decreased cell poliferation and nitrate production, but the inhibitory efffect of NMA was also prevented by the NO donor, sodium nitropruiside. These results suggest that exogenously synthesized NO was playing a stimulating effect on cell proliferation or on non-collagenous protein expression. Therefore NO have an important role in mediation of localized bone destruction associated inflammatory bone disease such as periodontitis.

• 폴리머
• /
• 제29권3호
• /
• pp.231-236
• /
• 2005

사슬 말단에 아민기를 갖는 폴리에테르이미드(AT-PEI)를 2,2'-bis[4-(3,4-dicarboxyphenoxy)-phenyl]propane dianhydride (BPADA)와 m-phenylenediamine의 반응에 의해 합성하였으며, BPADA와 m-phenylenediamine 및 3,5-diaminobenzoic acid의 반응에 의해 pendant 카복시기를 갖는 폴리에테르이미드(CP-PEI)를 합성하였다. 합성된 변성 PEI 들을 bisphenol-A의 diglycidyl ether에 첨가한 후 nadic methyl anhydride(NMA)로 경화시켜 에폭시 수지를 제조하고 열적 특성, 강인성 및 내용매성을 측정하였다. AT-PEI가 20 phr 첨가된 에폭시 수지는 내열의 저하 없이 파괴인성($K_{IC}$)가 2.88 $MPa{\cdot}m^{0.5}$로서 높은 강인성을 보였다. CP-PEI가 20phr 첨가된 에폭시 수지의 $K_{IC}$는 2.82$MPa{\cdot}m^{0.5}$이었다.

• Toxicological Research
• /
• 제12권2호
• /
• pp.195-201
• /
• 1996

Endotoxic shock causes death in humans and animals via extreme hypoperfusion of peripheral organs. A massive production of nitric oxide (NO) both from the endothelical cells and smooth muscle cells has been proposed as a possible mechanism in this process. Since NO attenuated the contractility to vasoconstricting agents such as norepinephrine (NE) by directly acting on the smooth muscle cells, this mechanism was considered mainly as a postsynaptic mechanism. In this research it was investigated whether NO, thus released, also participates in the presynaptic events for the regulation of vascular tone in endotoxic shock. The role of NO was studied by adding NO donors or NO synthase inhibitor $N^\omega $methyl-L-arginine (NMA) in stimulated sympathetic nerves of the mesenteric vascular bed and the Langendorff heart of rats. Sodium nitroprusside (SNP), an NO donor, reduced the pressor responses of isolated mesenteric artery either to electrical stimulation or exogenously administered phenylephrine (PE). In this mesentery, although neither agent influenced NE release, in the presence of the adrenergic $\alpha_2$-receptor antagonist yohimbine, elecrical stimulation-evoked NE release was augumented by SNP. In the heart SNP facilitated the NE release induced by electrical stimulation, while NMA had no effect. From these results it is proposed that there exists a local reflex phenomenon in the junction between the sympathetic nerve terminals and the smooth muscle of resistance blood vessels; by which sympathetic responses are reduced by NO at the postjunctional level while NO facilitates NE release contributing to augumentation of sympathetic tone. All these facts suggest that NO produced during endotoxic shock has dual effects: whereas NO blunts the vasoconstrictive activity of NE at the postsynaptic level, NO presynaptically facilitates the release of NE from sympathetic nerve terminals.

• Journal of Yeungnam Medical Science
• /
• 제16권1호
• /
• pp.76-84
• /
• 1999

악성 복수와 비악성 복수의 감별 진단은 진단과 치료 과정에서 매우 중요한 역할을 한다. 많은 계측치들이 감별을 위하여 사용되어져 왔는데 어느 것도 단독 사용시 두 군을 완벽히 구분짓지는 못한다. 이에 본 연구자들은 악성복수와 비악성 복수의 감별에 있어서 여러 계측치들을 비교하여 민감도와 특이도가 높은 계측치를 찾고 이 결과를 토대로 악성복수와 비악성 복수의 구분에서 간단하면서도 효과적인 진단방법을 찾고자 하였다. 1995년 1월부터 1997년 12월까지 영남대학교 의과대학 부속병원 내과에 복수를 주소로 내원하여 복수 천자를 시행한 80명을 대상으로 이들 환자들을 악성 복수 환자군과 비악성 복수 환자군으로 나누어 조사하였다. 악성 복수군은 다시 암종증이 동반된 21명의 환자와 암종증의 증거가 없는 6명의 환자로 구분하였고 비악성 복수군은 다시 52명의 간경변증 환자군과, 1명의 간경변증이 없는 군으로 구분하였다. 모든 환자에게서 복수와 혈액에서 동시에 검체가 얻어졌고 계측치로 복수액의 콜레스테롤, CEA, LDH, 단백치, 세포진 검사, 복수액과 혈청의 LDH 비, 단백비, 혈청-복수액 알부민 차를 구하였고, 각 계측치의 평균을 구하여 두 군을 비교하였는데, 모든 계측치가 통계적으로 유의한 차이를 보여 주었다. 저자는 각 계측치마다 각 측정치를 적용하여 가장 높은 민감도와 특이도를 보이는, 즉 가장 높은 진단 능력을 나타내는 측정치를 절단치로 정한 후각 계측치에 적용하여 진 양성, 진 음성, 가 양성, 가 음성으로 분류한 후 민감도, 특이도, 양성 기대도, 음성 기대도, 진단 능력을 산출하였고, 연구된 계측치 중 민감도가 높은 계측치인 복수액의 콜레스테롤을 선별검사의 단계에 적용하고, 특이도가 높은 계측치인 세포진 검사와 복수와 혈청의 단백비를 악성 복수로 분류된 군에 적용하여 악성 복수를 확진하는 2단계 진단 과정을 80명의 환자들에게 적용하여 다음 결과를 얻었다. 1) 복수액 분석 결과 복수액의 콜레스테롤치가(절단치: 30 mg/dl) 93%의 가장 높은 민감도를 보였고, 복수액의 세포진 검사와 복수액과 혈청의 단백비가(절단치: 0.5) 100%, 98%의 가장 높은 특이도를 나타내었다. 2) 2단계의 진단 과정을 통하여 복강내 암종 전이가 확인된 21명 모두 악성 복수군으로 분류되었다. 3) 광범위한 간전이가 있는 악성 복수 모두 비악성군으로 분류되었다. 4) 간 경변증으로 인한 52례에서 모두 비악성군으로 분류되었다. 5) 전체 진단 과정을 통해 총 27명의 악성 복수 중 81.5%인 22명이 악성 복수군으로 진단되었다. 이상의 결과를 토대로 본 연구자들이 제시한 진단 과정은 악성 복수와 비악성 복수의 감별 진단에 효과적인 방법으로 생각되며 더욱 정확한 진단을 위해서는 임상 양상, 방사선학적 검사, 기타 검사 등을 토대로 종합적인 판단이 필요하리라 생각된다.

• 한국복합재료학회:학술대회논문집
• /
• 한국복합재료학회 2002년도 춘계학술발표대회 논문집
• /
• pp.147-150
• /
• 2002

The cure kinetics of blends of epoxy (DGEBA:diglycidyl ether of bisphenol A)/anhydride (NMA:nadic methyl anhydride) resin with synthesized amino terminated polyetherimide (AT-PEI) were studied using differential scanning calorimetry (DSC) and Dynamic Mechanical Analysizer(DMA) under isothermal condition to determine the reaction parameters and gel-vitrification behavior. The fracture toughness of AT-PEI 20phr/epoxy resin system was improved over 224% and 42.5% more than neat epoxy resin and commercial PEI/Epoxy Resin System.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 1992년도 한국우주과학회보 제2권1호
• /
• pp.23-25
• /
• 1993

밀리미터파 영역에서의 관측장치를 살펴보면, 단일망원경을 제외하고도 세계의 밀리미터파 간섭계의 그 어느 것이나 현재 확장작업을 진행중이며, 또 밀리미터파서브밀리미터파영역에서의 고분해능 관측의 천문학적 성과를 올리기 위해 서브밀리미터파 간섭계의 건설계획을 추진하고 있고, NARO에서도 NMA계획을 발표하여 그 준비가 착착 진행되고 있다. 이들에 대해, 일본의 NRO에서도 HMA확충계획을 진행시키는 한편, 대형밀리미더파 간섭계(LMA) 계획을 발표하고 있다. 따라서 일본 내부에서는 SUBARU 망원경건설 이후의 천문학 분야에서의 차기 대형 장래계획으로서 LMA가 자리잡고 있다. 따라서 본 발표에서는, 세계의 이러한 추세 속에서 향후 5년 내지는 10년 이후를 내다보고 우리나라 전파천문학은 앞으로 무엇을 해 나가야 할 것인가, 그리고 무엇이 우리의 실정에 가장 적합한 천문학인지를 생각해 보기 위한 한 방편으로, 측지적인 목적과 전파천문학적인 견지에서의 국내 및 국외 VLBI Network 형성과 LMA 계획을 분석해보고자 한다.