• Journal of Dental Anesthesia and Pain Medicine
• /
• v.22 no.3
• /
• pp.233-237
• /
• 2022

Postpolio syndrome (PPS) is widely known to manifest as muscle weakness in patients affected by poliomyelitis in early childhood. This is caused by the long-term overwork of motor nerves regenerated from surviving nerve cells. We report a characteristic delay in recovery from muscle relaxation after administering rocuronium to a patient with PPS under general anesthesia with desflurane. A 59-year-old woman was scheduled to undergo surgical debridement for jaw osteonecrosis. She had a history of poliomyelitis at the age of 2 years, and was diagnosed with PPS at the age of 51 years. General anesthesia was induced with 80 mg propofol, 50 ㎍ fentanyl, and 30 mg (0.69 mg/kg) rocuronium, and maintained with desflurane and remifentanil. The durations of train-of-four (TOF) count 0 and 1 were 96 and 37 min, respectively. Five minutes after discontinuing desflurane, the TOF count was 4. Three minutes after administering 200 mg sugammadex, the TOF ratio was 0.83, and the tracheal tube was subsequently removed. In summary, the effect of a single dose of rocuronium on twitch in TOF monitoring was significantly prolonged in a patient with PPS, which may have been exacerbated by desflurane.

• Nuclear Engineering and Technology
• /
• v.56 no.4
• /
• pp.1532-1537
• /
• 2024

Time-of-flight (TOF) PET detectors with fast-rise-time scintillators and fast-single photon time resolution silicon photomultiplier (SiPM) have been developed to improve the coincidence timing resolution (CTR) to sub-100 ps. The CTR can be further improved with an optimal bandwidth and minimized electronic noise in the readout circuit and this helps reduce the distortion of the fast signals generated from the TOF-PET detector. The purpose of this study was to develop an ultra-high frequency and fully-differential (UF-FD) readout circuit that minimizes distortion in the fast signals produced using TOF-PET detectors, and suppresses the impact of the electronic noise generated from the detector and front-end readout circuits. The proposed UF-FD readout circuit is composed of two differential amplifiers (time) and a current feedback operational amplifier (energy). The ultra-high frequency differential (7 GHz) amplifiers can reduce the common ground noise in the fully-differential mode and minimize the distortion in the fast signal. The CTR and energy resolution were measured to evaluate the performance of the UF-FD readout circuit. These results were compared with those obtained from a high-frequency and single ended readout circuit. The experiment results indicated that the UF-FD readout circuit proposed in this study could substantially improve the best achievable CTR of TOF-PET detectors.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.48 no.6
• /
• pp.1-7
• /
• 2011

The depth camera measures range information of the scene in real time using Time-of-Flight (TOF) technology. Measured depth data is then regularized and provided as a depth image. This depth image is utilized with the stereo or multi-view image to generate high-resolution depth map of the scene. However, it is required to correct noise and distortion of TOF depth image due to the technical limitation of the TOF depth camera. The corrected depth image is combined with the color image in various methods, and then we obtain the high-resolution depth of the scene. In this paper, we introduce the principal and various techniques of sensor fusion for high-quality depth generation that uses multiple camera with depth cameras.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.51.2-51.2
• /
• 2015

Understanding interfacial phenomena has been one of the main research issues not only in semiconductors but only in life sciences. I have been trying to meet the atomic scale surface and interface analysis challenges from semiconductor industries and furthermore to extend the application scope to biomedical areas. Optical imaing has been most widely and successfully used for biomedical imaging but complementary ion beam imaging techniques based on mass spectrometry and ion scattering can provide more detailed molecular specific and nanoscale information In this presentation, I will review the 27 years history of medium energy ion scattering (MEIS) development at KRISS and DGIST for nanoanalysis. A electrostatic MEIS system constructed at KRISS after the FOM, Netherland design had been successfully applied for the gate oxide analysis and quantitative surface analysis. Recenlty, we developed time-of-flight (TOF) MEIS system, for the first time in the world. With TOF-MEIS, we reported quantitative compositional profiling with single atomic layer resolution for 0.5~3 nm CdSe/ZnS conjugated QDs and ultra shallow junctions and FINFET's of As implanted Si. With this new TOF-MEIS nano analysis technique, details of nano-structured materials could be measured quantitatively. Progresses in TOF-MEIS analysis in various nano & bio technology will be discussed. For last 10 years, I have been trying to develop multimodal nanobio imaging techniques for cardiovascular and brain tissues. Firstly, in atherosclerotic plaque imaging, using, coherent anti-stokes raman scattering (CARS) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) multimodal analysis showed that increased cholesterol palmitate may contribute to the formation of a necrotic core by increasing cell death. Secondly, surface plasmon resonance imaging ellipsometry (SPRIE) was developed for cell biointerface imaging of cell adhesion, migration, and infiltration dynamics for HUVEC, CASMC, and T cells. Thirdly, we developed an ambient mass spectrometric imaging system for live cells and tissues. Preliminary results on mouse brain hippocampus and hypotahlamus will be presented. In conclusions, multimodal optical and mass spectrometric imaging privides overall structural and morphological information with complementary molecular specific information, which can be a useful methodology for biomedical studies. Future challenges in optical and mass spectrometric imaging for new biomedical applications will be discussed.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.10 no.6
• /
• pp.96-103
• /
• 1996

This paper describes the electron transport characteristics in SF6 gas calculated for range of E/N values from 150~ 800[Td) by the Monte Carlo simulation and Boltzmann equation method using a set of electron collision cross sections detennined by the authors and the values of electron swarm parameters are obtained by TOF method. The results gRined that the values of the electron swarm parameters such as the electron drift velocity, the electron ionization or Rttachment coefficients, longitudinal and transverse diffusion coefficients agree with the experimental and theoretical for a range of E/N. The properties of electron avalanches is concerned electron energy non--equilibrium region. The electron energy distributions function were analysed in sulphur hexafluoride at E/N : 500~800[Td) for a case of non-equilibrium region in the mean electron energy. The validity of the results obtained has been confilll1ed by a TOF method.

• Journal of Ginseng Research
• /
• v.36 no.3
• /
• pp.277-290
• /
• 2012

The metabolic profiles of Panax quinquefolius and its associated therapeutic values are critically affected by the repetitious steaming times. The times-dependent steaming effect of P. quinquefolius is not well-characterized and there is also no official guideline on its times of steaming. In this paper, a UPLC-Q-TOF-MS/MS method was developed for the qualitative profiling of multi-parametric metabolic changes of raw P. quinquefolius during the repetitious steaming process. Our method was successful in discriminating the differentially multi-steamed herbs. Meantime, the repetitious steaming-inducing chemical transformations in the preparation of black American ginseng (American ginseng that was subjected to 9 cycles of steaming treatment) were evaluated by this UPLC-Q-TOF-MS/MS based chemical profiling method. Under the optimized UPLC-Q-TOF-MS/MS conditions, 29 major ginsenosides were unambiguously identified and/or tentatively assigned in both raw and multi-steamed P. quinquefolius within 19 min, among them 18 ginsenosides were detected to be newly generated during the preparatory process of black American ginseng. The mechanisms involved were further deduced to be hydrolysis, dehydration, decarboxylation and addition reactions of the original ginsenosides in raw P. quinquefolius through analyzing mimic 9 cycles of steaming extracts of 14 pure reference ginsenosides. Our novel steaming times-dependent metabolic profiling approach represents the paradigm shift in the global quality control of multi-steamed P. quinquefolius products.

• Analytical Science and Technology
• /
• v.30 no.6
• /
• pp.379-389
• /
• 2017

In this study, we set up an analytical method that can be used for rapid and accurate determination of representative isoquinoline alkaloids in medicinal plants using UPLC-ESI-Q-TOF MS (ultra pressure liquid chromatography-electrospray ionization-quadrupole-time-of-flight mass spectrometry). The compounds were eluted on a C18 column with 0.1 % formic acid and acetonitrile, and separated with good resolution within 13 min. Each of the separated components was characterized by precursor ions (generated by ESI-Q-TOF) and fragment ions (produced by collision-induced dissociation, CID), which were used as a reliable database. We also performed method validation: analytes showed excellent linearity ($R^2$, 0.9971-0.9996), LOD (5-25 ng/mL), LOQ (17-82 ng/mL), accuracy (91.6-97.4 %) as well as intra- and inter-day precisions (RSD, 1.8-3.2 %). In the analysis of Chelidonium majus L., magnoflorine, coptisine, sanguinarine, berberine and palmatine were detected by matching retention times and characteristic fragment ion patterns of reference standards. We also confirmed that, among the quantified components, coptisine was present in the highest quantity. Furthermore, alkaloid profiling was carried out by analyzing the fragment ion patterns corresponding to peaks of unknown components. In this manner, protopine, chelidonine, stylopine, dihydroberberine, canadine, and nitidine were tentatively identified. We also proposed the molecular structure of the fragment ions that appear in the mass spectrum. Therefore, we concluded that our suggested method for the determination of major isoquinoline alkaloids by UPLC-Q-TOF can be useful not only for quality control, but also for rapid and accurate investigation of phytochemical constituents of medicinal plants.

• Journal of Plant Biotechnology
• /
• v.39 no.4
• /
• pp.261-272
• /
• 2012

Environmental factors greatly influence the growth, development, and even genetic characteristics of plants. The mechanisms by which sound influences plant growth, however, remain obscure. Previously, our group reported that several genes were differentially regulated by specific frequenciesof sound treatmentusing a sound-treated subtractive library. In this study, we used a proteomic approach to investigate plant responses to sound waves in Arabidopsis. The plants were exposed to 250-Hz or 500-Hz sound waves, and total proteins were extracted from leaves 8 h and 24 h after treatment. Proteins extracted from leaves were subjected to 2-DE analysis. Thirty-eight spots were found to be differentially regulated in response to sound waves and were identified using MALDI-TOF MS and MALDI-TOF/TOF MS. The functions of the identified proteins were classified into photosynthesis, stress and defense, nitrogen metabolism, and carbohydrate metabolism. To the best of our knowledge, this is the first report on the analysis of protein changes in response to sound waves in Arabidopsis leaves. These findings provide a better understanding of the molecular basis of responses to sound waves in Arabidopsis.

• Journal of Life Science
• /
• v.15 no.3 s.70
• /
• pp.427-433
• /
• 2005

With the completely discovery of the Drosophila genome sequence, the next great challenge is to extract its biological information by systematic expression and to perform functional analysis of the gene. Here we reported a proteome analysis of D. melanogaster with two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption ionization time-of-flight mass spectrometer (MALDI-TOF-MS). The cell extracts of D. melanogaster, $200{\mu}g$ were resolved to more than 400 silver-stained spots by 2-DE. The most abundant protein spots were ranged from 4.0-7.5 of pI and from 15-90 kDa of molecular weight. The excised spots were destained and in-gel digested by trypsin. The masses of the resulting peptide mixtures were measured by MALDI-TOF-MS. Identified proteins were compared with measured peptide mass and a dynamic peptide searching database which is accessible via the internet. The results revealed that identified proteins were produced by 59 genes derived from 65 protein spots.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.23 no.2
• /
• pp.81-85
• /
• 2013

We performed analysis of composition and structure of coating layers by using ED-XRF and TOF-SIMS for some passion topaz of Swarovski which developed recently as new surface treatment of TCF (thermal color fusion) technique. In addition, we compared differences between Ti-coated topaz (Mystic topaz) and new treated colored topazes (passion topaz) with magnification observation and simplified durability test. As a result, we can observe similar characteristic clues in Ti-coated topaz and passion topaz by magnified observation. According to results of depth profile by TOF-SIMS, we can know that topaz is treated by multi-layer coating or surface diffusion coating. Moreover, the passion topaz which is treated by chemical reaction between metal elements shows more stable chemical resistance and higher Mohs' hardness than Ti-coated topaz.