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排序方式: 共有1048条查询结果,搜索用时 0 毫秒
31.
Hyo-Uk Kim Chung Yi Shi-Woo Rhee 《Journal of Materials Science: Materials in Electronics》2004,15(1):37-41
The effect of O2 plasma pretreatment on the SiO2/Si interface property was studied using direct plasma varying the plasma power, He or Ar/O2 ratio and the pretreatment time. The decrease of the pretreatment plasma power decreased the plasma damage and improved the interface property. The addition of He in O2 glow discharge improved the electrical and the interface properties and there was an optimum He/O2 ratio. The improvement of the interface property by Ar/O2-plasma pretreatment was better than that by He/O2, which is believed to be due to the lower oxidation rate of the Si surface. C–V analysis showed that the Pb center defect density was influenced by plasma pretreatment process parameters. To investigate the oxidation states near to and at the SiO2/Si interface, X-ray photoelectron spectroscopy depth analysis was used and the gas phase in the glow discharge was investigated using optical emission spectroscopy analysis at various experimental conditions. 相似文献
32.
Chang-Gun Lee Chanoh Park Soonjae Hwang Ju-Eun Hong Minjeong Jo Minseob Eom Yongheum Lee Ki-Jong Rhee 《International journal of molecular sciences》2022,23(10)
Despite advances in medicine, mortality due to sepsis has not decreased. Pulsed electromagnetic field (PEMF) therapy is emerging as an alternative treatment in many inflammation-related diseases. However, there are few studies on the application of PEMF therapy to sepsis. In the current study, we examined the effect of PEMF therapy on a mouse model of lipopolysaccharide (LPS)-induced septic shock. Mice injected with LPS and treated with PEMF showed higher survival rates compared with the LPS group. The increased survival was correlated with decreased levels of pro-inflammatory cytokine mRNA expression and lower serum nitric oxide levels and nitric oxide synthase 2 mRNA expression in the liver compared with the LPS group. In the PEMF + LPS group, there was less organ damage in the liver, lungs, spleen, and kidneys compared to the LPS group. To identify potential gene targets of PEMF treatment, microarray analysis was performed, and the results showed that 136 genes were up-regulated, and 267 genes were down-regulated in the PEMF + LPS group compared to the LPS group. These results suggest that PEMF treatment can dramatically decrease septic shock through the reduction of pro-inflammatory cytokine gene expression. In a clinical setting, PEMF may provide a beneficial effect for patients with bacteria-induced sepsis and reduce septic shock-induced mortality. 相似文献
33.
The effect of carrier gas such as hydrogen, nitrogen and argon on the deposition rate, film morphology, resistivity and chemical composition of TiN film from tetrakis-dimethyl-amido-titanium (TDMAT) was studied. The deposition rate was higher with argon and nitrogen and lower with hydrogen when the substrate temperature was above 300°C. The surface morphology of the film deposited with hydrogen carrier gas was rough due to the gas phase reaction. The film deposited at the higher substrate temperature with hydrogen had higher resistivity than in the film deposited with argon or nitrogen due to the rough surface. 相似文献
34.
Haneul Lee Su Jin Kang Jimin Lee Kyong Hwa Park Won Jong Rhee 《International journal of molecular sciences》2022,23(13)
Prostate cancer (PCa) is the most commonly diagnosed malignancy among men in developed countries. The five-year survival rate for men diagnosed with early-stage PCa is approximately 100%, while it is less than 30% for castration-resistant PCa (CRPC). Currently, the detection of prostate-specific antigens as biomarkers for the prognosis of CRPC is criticized because of its low accuracy, high invasiveness, and high false-positive rate. Therefore, it is important to identify new biomarkers for prediction of CRPC progression. Extracellular vesicles (EVs) derived from tumors have been highlighted as potential markers for cancer diagnosis and prognosis. Specifically, urinary EVs directly reflect changes in the pathophysiological conditions of the urogenital system because it is exposed to prostatic secretions. Thus, detecting biomarkers in urinary EVs provides a promising approach for performing an accurate and non-invasive liquid biopsy for CPRC. In this study, we effectively isolated urinary EVs with low protein impurities using size-exclusion chromatography combined with ultrafiltration. After EV isolation and characterization, we evaluated the miRNAs in urinary EVs from healthy donors and patients with CRPC. The results indicated that miRNAs (miR-21-5p, miR-574-3p, and miR-6880-5p) could be used as potential biomarkers for the prognosis of CRPC. This analysis of urinary EVs contributes to the fast and convenient prognosis of diseases, including CRPC, in the clinical setting. 相似文献
35.
The wear of friction materials as measured by isothermal techniques remains insensitive to temperature to about 230°C (drum) and increases exponentially at higher temperatures. The high temperature wear of organic friction materials was found to be related to the thermal decomposition of the organic ingredients with an activation energy of 4–10 kcal mol?1. The results indicate that high temperature wear of semimetallic friction materials is controlled by thermal degradation of organic ingredients as it is for organic friction materials. 相似文献
36.
In this paper, the threshold voltage instability characteristics of HfO2 high-k dielectric are discussed. The results from various stress bias conditions including DC and AC with variations of frequency, duty cycle, and polarity provide additional insights into the intrinsic behavior and the trapping dynamics of high-k materials. A reduced threshold voltage shift was observed at higher frequency and lower duty cycle under AC positive unipolar stress compared to DC stress. Similarly, the degradation of maximum transconductance was also reduced with AC stress. However, subthreshold swing changes were found to be negligible and fairly independent of stress frequencies and duty cycles under AC positive unipolar stress.When different polarity of stress, such as positive, negative, and bipolar stress was applied, it was observed that frequency and duty cycle dependencies were still valid in all three conditions. In contrast to positive stress, negative stress showed a decrease in the threshold voltage shift. Bipolar stress resulted in the highest threshold voltage instability, but the degradation in transconductance and subthreshold swing was actually smaller than those in negative unipolar stress. The bulk trap of HfO2 dielectric, which is proportional to its physical thickness, is believed to be the primary factor for threshold voltage shift. AC unipolar operation would allow a higher 10-year lifetime operating voltage than the DC condition. In addition to experimental results, a plausible mechanism has been proposed. 相似文献
37.
Woosung Kwon Gyeongjin Lee Sungan Do Taiha Joo Shi‐Woo Rhee 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(3):506-513
Size‐controlled soft‐template synthesis of carbon nanodots (CNDs) as novel photoactive materials is reported. The size of the CNDs can be controlled by regulating the amount of an emulsifier. As the size increases, the CNDs exhibit blue‐shifted photoluminescence (PL) or so‐called an inverse PL shift. Using time‐correlated single photon counting, ultraviolet photoelectron spectroscopy, and low‐temperature PL measurements, it is revealed that the CNDs are composed of sp2 clusters with certain energy gaps and their oleylamine ligands act as auxochromes to reduce the energy gaps. This insight can provide a plausible explanation on the origin of the inverse PL shift which has been debatable over a past decade. To explore the potential of the CNDs as photoactive materials, several prototypes of CND‐based optoelectronic devices, including multicolored light‐emitting diodes and air‐stable organic solar cells, are demonstrated. This study could shed light on future applications of the CNDs and further expedite the development of other related fields. 相似文献
38.
39.
The current study involved methodology and content analyses of abstracts of 30 clinical decision support system (CDSS) related studies with high impact factors. The main aim of the current work was to identify the performance and efficiency of CDSS, and enhance the understanding of CDSS for a better health management among the physicians and the patients. To add structure to the current study, major research areas were categorized based on a multidimensional unfolding analysis. In this regard, eight studies were conducted based on theoretical research, ten studies were related to the system and performance of CDSS, and 12 studies verified the efficacy through analysis and evaluation of CDSS. The results indicated that the above-mentioned studies on improvement in systematic performance. Then, based on the improvement, effectively used evaluations were conducted comparably. Moreover, 14 studies analyzed patients’ data and assessed decision support system (DSS). The related findings denoted that DSS has been mainly used for patient management and a large number of studies have verified its effectiveness, using several data to ensure its accuracy and reliability. In addition, the analyzed results of the abstracts and the titles were compared to find whether the titles of the literature articles reveal their content. Using these methodological studies, the academic outlook of medical informatics could be forecasted and the academic quality could be improved by resolving the problems, arising out of system development and realization processes. Such problems can be solved through analyses and interpretation of multilateral parameters, such as the trend in academic development, research direction, topics and methods. 相似文献
40.
Disturbances and changes in the welding working environment lead to possible variations in the output variables associated with weld quality. In order to enhance weld quality, it is essential to optimize the welding process by taking the variance as well as the average value of the output variables into consideration. In this study, the dual response approach is adopted to determine the welding process parameters, which produce the target value with minimal variance. The dual response approach optimizes the penetration in gas metal arc (GMA) welding through the procedures as follows. First, the regression models of the mean value and standard deviation of the penetration are induced through regression analysis. Subsequently, an optimization algorithm based on the regression models and constraints is applied to determine the welding process parameters, which generate the desired penetration with minimized variance. In particular, the genetic algorithm, a global optimization algorithm, is adopted in this study to determine the optimal solution. 相似文献