Water-soluble Core/Shell Nanoparticles for Proton Therapy through Particle-induced Radiation

박정찬,정명환,김맹준,김계령 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.3

Metallic nanoparticles have been used in biomedical applications such as magnetic resonanceimaging (MRI), therapy, and drug delivery systems. Metallic nanoparticles as therapeutic toolshave been demonstrated using radio-frequency magnetic fields or near-infrared light. Recently, therapeuticapplications of metallic nanomaterials combined with proton beams have been reported. Particle-induced radiation from metallic nanoparticles, which can enhance the therapeutic effectsof proton therapy, was released when the nanoparticles were bombarded by a high-energy protonbeam. Core/shell nanoparticles, especially Au-coated magnetic nanoparticles, have drawn attentionin biological applications due to their attractive characteristics. However, studies on the phasetransfer of organic-ligand-based core/shell nanoparticles into water are limited. Herein, we demonstratedthat hydrophobic core/shell structured nanomaterials could be successfully dispersed inwater through chloroform/surfactant mixtures. The effects of the core/shell nanomaterials and theproton irradiation on Escherichia coli (E. coli) were also explored.

Preoperative 2D-echocardiographic assessment of pulmonary arterial pressure in subgroups of liver transplantation recipients

박정찬,Park Myung Soo,Kwon Ji-Hye,Oh Ah Ran,Lee Seung-Hwa,Choi Gyu-Seong,Kim Jong Man,Kim Keoungah,김갑수 대한마취통증의학회 2021 Anesthesia and pain medicine Vol.16 No.4

Background: The clinical efficacy of preoperative 2D-echocardiographic assessment of pulmonary arterial pressure (PAP) has not been evaluated fully in liver transplantation (LT) recipients.Methods: From October 2010 to February 2017, a total of 344 LT recipients who underwent preoperative 2D-echocardiography and intraoperative right heart catheterization (RHC) was enrolled and stratified according to etiology, disease progression, and clinical setting. The correlation of right ventricular systolic pressure (RVSP) on preoperative 2D-echocardiography with mean and systolic PAP on intraoperative RHC was evaluated, and the predictive value of RVSP > 50 mmHg to identify mean PAP > 35 mmHg was estimated.Results: In the overall population, significant but weak correlations were observed (R = 0.27; P < 0.001 for systolic PAP, R = 0.24; P < 0.001 for mean PAP). The positive and negative predictive values of RVSP > 50 mmHg identifying mean PAP > 35 mmHg were 37.5% and 49.9%, respectively. In the subgroup analyses, correlations were not significant in recipients of deceased donor type LT (R = 0.129; P = 0.224 for systolic PAP, R = 0.163; P = 0.126 for mean PAP) or in recipients with poorly controlled ascites (R = 0.215; P = 0.072 for systolic PAP, R = 0.21; P = 0.079 for mean PAP). Conclusion: In LT recipients, the correlation between RVSP on preoperative 2D-echocardiography and PAP on intraoperative RHC was weak; thus, preoperative 2D-echocardiography might not be the optimal tool for predicting intraoperative PAP. In LT candidates at risk of pulmonary hypertension, RHC should be considered.

Effects of Surface Charge and Ligand Type of Au Nanoparticles on Green Fluorescent Protein-expressing Escherichia coli

박정찬,이경태,김창섭,서정현 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.1

The effects of the surface charge and ligand type of three types of Au nanoparticles (NPs), namely anionic polyethylene glycol (PEG)-Au NPs, anionic citrate (Cit)-Au NPs, and cationic branched polyethylenimine (bPEI)-Au NPs, on green fluorescent protein (GFP)- expressing Escherichia coli were evaluated through the combined analysis of optical density (OD) and fluorescence intensity (FI). OD and FI can provide information about cell growth and metabolism of bacteria, respectively. The results demonstrated that PEG- and Cit-Au NPs had no major effects on the OD and FI of GFP-expressing bacteria. However, it was found that Cit-Au NPs may slightly influence cell metabolism at higher concentrations, although it is necessary to perform further in-depth study to clarify this issue. Cationic bPEI-Au NPs showed significant effects on cell density and metabolism of E. coli, with an especially strong effect on metabolism. The combined analysis of OD and FI may be useful for monitoring the effects of a wide range of nanomaterials on microorganisms.

R5 Peptide-based Biosilicification Using Methyltrimethoxysilane

박정찬,김도현,김창섭,서정현 한국생물공학회 2018 Biotechnology and Bioprocess Engineering Vol.23 No.1

We examined the performance of methyltrimethoxysilane (MTMS), a precursor of silicic acid, in the process of biosilicification induced by the R5 peptide from Cylindrotheca fusiformis. Recombinant GFP-R5 fusion protein was produced by Escherichia coli cultured at 25°C as a soluble and functional formation, but not at 37°C. MTMS-based biosilica deposits had a larger average diameter compared to tetraethyl orthosilicate (TEOS)-based deposits. Reducing phosphate concentration in the buffer system led to a decrease in the size of MTMS-based biosilica. These results provide insight into the surface modification of biosilica, and control of biosilica particle size, when using hydrophobic precursors such as MTMS.

4代 地方選擧의 意義

박정찬 慶尙大學校 經營行政大學院 1995 最高管理者課程論文集 Vol.8 No.-

Myocardial injury in noncardiac surgery

박정찬,이종환 대한마취통증의학회 2022 Korean Journal of Anesthesiology Vol.75 No.1

Myocardial injury is defined as an elevation of cardiac troponin (cTn) levels with or without associated ischemic symptoms. Robust evidence suggests that myocardial injury increases postoperative mortality after noncardiac surgery. The diagnostic criteria for myocardial injury after noncardiac surgery (MINS) include an elevation of cTn levels within 30 d of surgery without evidence of non-ischemic etiology. The majority of cases of MINS do not present with ischemic symptoms and are caused by a mismatch in oxygen supply and demand. Predictive models for general cardiac risk stratification can be considered for MINS. Risk factors include comorbidities, anemia, glucose levels, and intraoperative blood pressure. Modifiable factors may help prevent MINS; however, further studies are needed. Recent guidelines recommend routine monitoring of cTn levels during the first 48 h post-operation in high-risk patients since MINS most often occurs in the first 3 days after surgery without symptoms. The use of cardiovascular drugs, such as aspirin, antihypertensives, and statins, has had beneficial effects in patients with MINS, and direct oral anticoagulants have been shown to reduce the mortality associated with MINS in a randomized controlled trial. Myocardial injury detected before noncardiac surgery was also found to be associated with postoperative mortality, though further studies are needed.

주얼리용 은합금의 레이저 가공특성

박정찬,김우순,김동현 한국공작기계학회 2007 한국공작기계학회 추계학술대회논문집 Vol.2007 No.-

It is absolutely that jewelry industry are cut and formed by using Nd-YAG laser for most accuracy shapes. Moreover, Jewelry manufacturing is needed to be more precise working, more saved time and more improved finance. So, This Study will show the ideas which make exactly formed shape and advanced qualities when cutting Ag-alloy. This ideas will give the fact that beginners are able to use easily to change and compound the form of jewelries by using Nd-YAG laser.

나의 35년 낙종기

박정찬 관훈클럽 2021 관훈저널 Vol.- No.159

Study of the Effects of High-Energy Proton Beams on Escherichia Coli

박정찬,정명환 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.8

Antibiotic-resistant bacterial infection is one of the most serious risks to public health care today. However, discouragingly, the development of new antibiotics has progressed little over the last decade. There is an urgent need for alternative approaches to treat antibiotic-resistant bacteria. Novel methods, which include photothermal therapy based on gold nano-materials and ionizing radiation such as X-rays and gamma rays, have been reported. Studies of the effects of high-energy proton radiation on bacteria have mainly focused on Bacillus species and its spores. The effect of proton beams on Escherichia coli (E. coli) has been limitedly reported. Escherichia coli is an important biological tool to obtain metabolic and genetic information and is a common model microorganism for studying toxicity and antimicrobial activity. In addition, E. coli is a common bacterium in the intestinal tract of mammals. In this research, the morphological and the physiological changes of E. coli after proton irradiation were investigated. Diluted solutions of cells were used for proton beam radiation. LB agar plates were used to count the number of colonies formed. The growth profile of the cells was monitored by using the optical density at 600 nm. The morphology of the irradiated cells was observed with an optical microscope. A microarray analysis was performed to examine the gene expression changes between irradiated samples and control samples without irradiation. E coli cells have observed to be elongated after proton irradiation with doses ranging from 13 to 93 Gy. Twenty-two were up-regulated more than twofold in proton-irradiated samples (93 Gy) compared with unexposed one.

칼라 특징을 이용한 내용기반 화상검색시스템의 설계 및 구현 ( The Design and Implementation of Content-Based Large Retrieval System Using the Color Features )

박정찬,최현섭,최기호,김철원,정원일 대한전자공학회 1995 대한전자공학회 학술대회 Vol.1995 No.11