• Mass Spectrometry Letters
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• 제12권4호
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• pp.137-145
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• 2021

Herein we report multiple ion mobility (IM) peaks in electrospray ionization IM mass spectrometry (ESI-IM-MS) produced by glutamine residue in peptide. The mobility features of 147 peptides were investigated using ESI-IM-MS combined with liquid chromatography. Of these peptides, 66 presented multiple IM peaks, and analysis of their sequence using collision induced dissociation (CID) revealed that glutamine (Gln), as well as proline (Pro), plays a critical role in generating multiple IM peaks. Mutant-based investigations using Gln-containing peptides indicate that the side chain of Gln promotes intermolecular interactions, inducing multiple structures of the peptide ions in the gas phase. Consequently, the present study demonstrates that the distinct ion mobility signatures identified herein can potentially be used to characterize glutamine-containing peptide ions.

• 한국환경보건학회지
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• 제16권2호
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• pp.11-20
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• 1990

To investigate ionic characteristics of acid rain by the succeeding rainfall. bulk precipitation was collected every each 5mm rainfall from march to october 1990 at Dae Jeon area. pH, sulfate nitrate, chloride, ammonium ion was measured and analyzed. The result was as follows: 1. The weighted average pH of rain was 5.1$\pm$ 0.72(4.15~7.6) and rain pH less than 5.5 was appeared 51.3% 2. Average ion concentrations of sulfate, nitrate, chloride and ammonium ion was 125.12 $\mu$eq/l, 62.38 $\mu$eq/l, 31.95 $\mu$eq/l, 66.6 $\mu$eq/l and rates of each anions was 57%, 28.4%, 14.6% and rate of sulfate by nitrate was 2 times. 3. There is no correlations time interval of rainfall and Ion concentration change. 4. From initial to 15mm rainfall, each ion concentrations were decreased. and average concentration of pH, SO$^{-2}_{4}$, Cl ion concentration was increased in the succeeding rainfall 5. Only sulfate ion was correlated by the simple regression analysis with pH except NO$^{-}_{3}$, Cl$^{-}$ and NH$_{4}^{+}$ Cl$^{-}$ correlation coefficient was very high at the multiple regression analysis with pH. 6. Simple & multiple correlation coefficient among anions and NH$^{+}_{4}$ was very high especially N$^{+}_{4}$ and SO$^{2-}_{4}$ at simple regression analysis and SO$^{-2}_{4}$ and NO$_{3}^{-}$, Cl$^{-}$, NH$_{4}^{-}$ at multiple regression analysis.

• Archives of Pharmacal Research
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• 제5권2호
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• pp.71-77
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• 1982

Improvements in the analytical methodology used in the gas chromatographic/mass spectral analysis of phenolic compounds from cigarette smoke are described. For the direct analysis of crude samples, pyridine extraction and the glass capillary column GC was used for the separation of phenolics as trimethylsilyl derivativatives. The separations of cigarette smoke on Carbowax 20M and SE-54 wall coated open tubular columns are given. Improved methodology for the routine quantitation of the identified components using the computer-controlled multiple ion selection technique of MS presented. Considerations pertaining to routine analyses of a multitude of complex smoke samples are also discussed.

• Mass Spectrometry Letters
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• 제7권3호
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• pp.64-68
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• 2016

Scanning electron microscopy combined with thermal ionization mass spectrometry (SEM-TIMS) was used to determine the precise isotope ratios of ultra-trace levels of uranium contained in individual microparticles. An advanced multiple ion counter system consisting of three secondary ion multipliers and two compact discrete dynodes was used for complete simultaneous ion detection. For verification purposes, using TIMS with complete simultaneous measurement, isotopes were analyzed in 5 pg of uranium of a certified reference material. A microprobe in the SEM was used to transfer individual particles from a NUSIMEP-7 sample to TIMS filaments, which were then subjected to SEM-TIMS and complete simultaneous measurement. The excellent agreement in the resulting uranium isotope ratios with the certified NUSIMEP-7 values shows the validity of SEM-TIMS with complete simultaneous measurement for the analysis of uranium isotopes in individual particles. Further experimental study required for investigation of simultaneous measurement using the advanced multiple ion counter system is presented.

• Genes and Genomics
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• 제40권12호
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• pp.1331-1338
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• 2018

Although there have been plenty of dominance deviation analysis, few studies have dealt with multiple phenotypes. Because researchers focused on multiple phenotypes (final weight and backfat thickness) of Landrace pigs, the classification of the genes was possible. With genome-wide association studies (GWASs), we analyzed the additive and dominance effects of the single nucleotide polymorphisms (SNPs). The classification of the pig genes into four categories (overdominance in final weight, overdominance in backfat thickness and overdominance in final weight, underdominance in backfat thickness, etc.) can enable us not only to analyze each phenotype's dominant effects, but also to illustrate the gene ontology (GO) analysis with different aspects. We aimed to determine the additive and dominant effect in backfat thickness and final weight and performed GO analysis. Using additive model and dominance deviation analysis in GWASs, Landrace pigs' overdominant and underdominant SNP effects in final weight and backfat thickness were surveyed. Then through GO analysis, we investigated the genes that were classified in the GWASs. The major GO terms of the underdominant effects in final weight and overdominant effects in backfat thickness were ion transport with the SLC8A3, KCNJ16, P2RX7 and TRPC3 genes. Interestingly, the major GO terms in the underdominant effects in the final weight and the underdominant effects in the backfat thickness were the regulation of ion transport with the STAC, GCK, TRPC6, UBASH3B, CAMK2D, CACNG4 and SCN4B genes. These results demonstrate that ion transport and ion transport regulation genes have distinct dominant effects. Through GWASs using the mode of linear additive model and dominance deviation, overdominant effects and underdominant effects in backfat thickness was contrary to each other in GO terms (ion transport and ion transport regulation, respectively). Additionally, because ion transport and ion transport regulation genes are associative with adipose tissue accumulation, we could infer that these two groups of genes had to do with unique fat accumulation mechanisms in Landrace pigs.

• The Korean Journal of Physiology and Pharmacology
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• 제27권1호
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• pp.85-94
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• 2023

Ion channels regulate a large number of cellular functions and their functional role in many diseases makes them potential therapeutic targets. Given their diverse distribution across multiple organs, the roles of ion channels, particularly in age-associated transcriptomic changes in specific organs, are yet to be fully revealed. Using RNA-seq data, we investigated the rat transcriptomic profiles of ion channel genes across 11 organs/tissues and 4 developmental stages in both sexes of Fischer 344 rats and identify tissue-specific and age-dependent changes in ion channel gene expression. Organ-enriched ion channel genes were identified. In particular, the brain showed higher tissue-specificity of ion channel genes, including Gabrd, Gabra6, Gabrg2, Grin2a, and Grin2b. Notably, age-dependent changes in ion channel gene expression were prominently observed in the thymus, including in Aqp1, Clcn4, Hvcn1, Itpr1, Kcng2, Kcnj11, Kcnn3, and Trpm2. Our comprehensive study of ion channel gene expression will serve as a primary resource for biological studies of aging-related diseases caused by abnormal ion channel functions.

• 한국정밀공학회지
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• 제24권10호
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• pp.109-116
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• 2007

Focused ion beams are a potential tool for micro/nano structure fabrication while several problems still have to be overcome. Redeposition of sputtered atoms limits the accurate fabrication of micro/nano structures. The challenge lies in accurately controlling the focused ion beam to fabricate various arbitrary curved shapes. In this paper a basic approach for the focused ion beam induced direct fabricate of fundamental features is presented. This approach is based on the topography simulation which naturally considers the redeposition of sputtered atoms and sputtered yield changes. Fundamental features such as trapezoidal, circular and triangular were fabricated with this approach using single or multiple pass box milling. The beam diameter(FWHM) and maximum current density are 68 nm and $0.8 A/cm^2$, respectively. The experimental investigations show that the fabricated shape is well suited for the pre-designed fundamental features. The characteristics of ion beam induced direct fabrication and shape formation will be discussed.

• Korean Chemical Engineering Research
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• 제43권1호
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• pp.27-32
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• 2005

본 연구에서는 다양한 공용매로 변형된 초임계 이산화탄소를 이용하여 웨이퍼 표면에 존재하는 이온주입 포토레지스트(IIP, ion-implanted photoresist) 및 잔류 불순물의 제거 공정을 97, 148, $200^{\circ}C$의 온도와 200, 300, 400 bar의 압력조건에서 수행하였다. 이온주입 포토레지스트는 순수 초임계 이산화탄소에 의해 제거되지 않았으나 팽윤(swelling)되는 것을 확인할 수 있었다. 또한, 단일 공용매 및 비양성자성 용매들의 혼합 공용매로 변형된 초임계 이산화탄소 시스템은 이온주입 포토레지스트를 팽윤시키나, 제거에 효과적이지 못하였다. 그러나 DMSO에 DIW가 혼합된 혼합 공용매(5%, v/v)로 변형된 초임계 이산화탄소 시스템은 $97^{\circ}C$, 200 bar의 온도, 압력 조건에서 30분 동안 세정 실험을 수행한 결과 이온 주입 포토레지스트의 제거에 효과적이었다(약 80%). 본 연구에서 사용된 혼합 공용매로 변형된 초임계 이산화탄소 시스템은 플라즈마 애싱(ashing) 및 산과 용매가 기본이 되는 습식 세정 방법의 대안으로서 화학액의 사용과 폐수를 감소시킬 수 있다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.153-153
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• 2022

There is a growing need to develop ion sensors for agriculture. As a result, several technologies have been developed, such as colorimetry, spectrophotometry, and ion-selective electrode (ISE). Among them, ISE has some advantages compared to others. First, it does not require pre-treatment processes and expensive equipment. Second, it is possible for the portable detection system by introducing small-sized electrodes. Finally, real-time and multiple detections of several ions are pursued. It is well-known that N, P, and K nutrients are critical for crop growth. With the development of agriculture techniques, the importance of soil nutrient analysis has attracted much attention for cost-effective and eco-friendly agriculture. Among several issues, minimizing the use of fertilizers is significant through quantitative analysis of soil nutrients. As a result, it is highly important to analyze certain nutrients, such as N (ammonium ion, nitrate ion, nitrite ion), P (dihydrogen phosphate ion, monohydrogen phosphate ion), and K (potassium ion). Therefore, developing sensors for accurate analysis of soil nutrients is highly desired. n this study, several ISEs have been fabricated to detect N, P, and K. Their performance has been intensively studied, such as sensitivity, selectivity coefficient, and concentration range, and compared with commercialized ISEs. In addition, preliminary tests on the in-situ N, P, and K monitoring have been conducted inside the soil.

• 센서학회지
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• 제6권2호
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• pp.131-136
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• 1997

The ISFET(ion sensitive field effect transistor), a semiconductor ion sensor, has many advantages over conventional ion sensors. Various single-sensor type ISFET pH-meters have been developed. However, they could not be applied in fields because their performances are directly affected by the sensor condition. With only one sensor, the system could be easily damaged from environmental factors, and reliability of it is decreased. Therefore, a 4-channel PH-meter system is proposed to improve the reliability of ISFET pH-meter. It has 4 ISFETS as ion sensor, and a software which contains a new calibration and measurement algorithm appropriate to the system. The reliability of the system was proved by measuring hydrogen ion concentration in the pH standard solutions and buffer solutions.