http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Effect of Patient Characteristics on Vessel Enhancement at Lower Extremity CT Angiography
Takanori Masuda,Takeshi Nakaura,Yoshinori Funama,Tomoyasu Sato,Toru Higaki,Masao Kiguchi,Yukari Yamashita,Naoyuki Imada,Kazuo Awai 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.2
Objective: To evaluate the effect of patient characteristics on popliteal aortic contrast enhancement at lower extremity CT angiography (LE-CTA) scanning. Materials and Methods: Prior informed consent to participate was obtained from all 158 patients. All were examined using a routine protocol; the scanning parameters were tube voltage 100 kVp, tube current 100 mA to 770 mA (noise index 12), 0.5-second rotation, 1.25-mm detector row width, 0.516 beam pitch, and 41.2-mm table movement, and the contrast material was 85.0 mL. Cardiac output (CO) was measured with a portable electrical velocimeter within 5 minutes of starting the CT scan. To evaluate the effects of age, sex, body size, CO, and scan delay on the CT number of popliteal artery, the researchers used multivariate regression analysis. Results: A significant positive correlation was seen between the CT number of the popliteal artery and the patient age (r = 0.39, p < 0.01). A significant inverse correlation was observed between the CT number of the popliteal artery and the height (r = -0.48), total body weight (r = -0.52), body mass index (r = -0.33), body surface area (BSA) (r = -0.56), lean body weight (r = -0.56), and CO (r = -0.35) (p < 0.001 for all). There was no significant correlation between the enhancement and the scan delay (r = 0.06, p = 0.47). The BSA, CO, and age had significant effects on the CT number (standardized regression: BSA -0.42, CO -0.22, age 0.15; p < 0.05, respectively). Conclusion: The BSA, CO, and age are significantly correlated with the CT number of the popliteal artery on LE-CTA.
Takanori Masuda,Takeshi Nakaura,Yoshinori Funama,Tomoyasu Sato,Toru Higaki,Masao Kiguchi,Yoriaki Matsumoto,Yukari Yamashita,Naoyuki Imada,Kazuo Awai 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.6
Objective: We evaluated the effect of various patient characteristics and time-density curve (TDC)-factors on the test bolus-affected vessel enhancement on coronary computed tomography angiography (CCTA). We also assessed the value of generalized linear regression models (GLMs) for predicting enhancement on CCTA. Materials and Methods: We performed univariate and multivariate regression analysis to evaluate the effect of patient characteristics and to compare contrast enhancement per gram of iodine on test bolus (ΔHUTEST) and CCTA (ΔHUCCTA). We developed GLMs to predict ΔHUCCTA. GLMs including independent variables were validated with 6-fold cross-validation using the correlation coefficient and Bland–Altman analysis. Results: In multivariate analysis, only total body weight (TBW) and ΔHUTEST maintained their independent predictive value (p < 0.001). In validation analysis, the highest correlation coefficient between ΔHUCCTA and the prediction values was seen in the GLM (r = 0.75), followed by TDC (r = 0.69) and TBW (r = 0.62). The lowest Bland–Altman limit of agreement was observed with GLM-3 (mean difference, -0.0 ± 5.1 Hounsfield units/grams of iodine [HU/gI]; 95% confidence interval [CI], -10.1, 10.1), followed by ΔHUCCTA (-0.0 ± 5.9 HU/gI; 95% CI, -11.9, 11.9) and TBW (1.1 ± 6.2 HU/gI; 95% CI, -11.2, 13.4). Conclusion: We demonstrated that the patient’s TBW and ΔHUTEST significantly affected contrast enhancement on CCTA images and that the combined use of clinical information and test bolus results is useful for predicting aortic enhancement.
Characteristics of PM Synchronous Motor with Trapezoidal EMF driven by Novel PWM Strategy
Katsunori Taniguchi,Toru Masuda,Toshimitsu Morizane,Noriyuki Kimura,Hyun-Woo Lee 전력전자학회 2004 ICPE(ISPE)논문집 Vol.- No.-
A new modified trapezoidal modulating signal for pulse width modulation (PWM) inverter suitable for the Permanent Magnet synchronous motor (PMSM) drive is proposed in this paper. A new modulating signal for the PMSM drive is determined by the condition of reducing torque ripple of the motor with various electromotive force (EMF). Proposed modulating signal is able to decrease the torque ripple even if the motor has sinusoidal EMF or non-sinusoidal EMF. By using the proposed modulating signal, the system reduced the torque ripple as well as achieving the effective utilization of the DC supply voltage for the inverter. Many improvements are accomplished by the PWM strategy adapting the modified trapezoidal modulating signal without a change in hardware.
Redox-coupled proton transfer mechanism in nitrite reductase revealed by femtosecond crystallography
Fukuda, Yohta,Tse, Ka Man,Nakane, Takanori,Nakatsu, Toru,Suzuki, Mamoru,Sugahara, Michihiro,Inoue, Shigeyuki,Masuda, Tetsuya,Yumoto, Fumiaki,Matsugaki, Naohiro,Nango, Eriko,Tono, Kensuke,Joti, Yasumas National Academy of Sciences 2016 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.113 No.11
<P>Proton-coupled electron transfer (PCET), a ubiquitous phenomenon in biological systems, plays an essential role in copper nitrite reductase (CuNiR), the key metalloenzyme in microbial denitrification of the global nitrogen cycle. Analyses of the nitrite reduction mechanism in CuNiR with conventional synchrotron radiation crystallography (SRX) have been faced with difficulties, because X-ray photoreduction changes the native structures of metal centers and the enzyme-substrate complex. Using serial femtosecond crystallography (SFX), we determined the intact structures of CuNiR in the resting state and the nitrite complex (NC) state at 2.03- and 1.60-angstrom resolution, respectively. Furthermore, the SRX NC structure representing a transient state in the catalytic cycle was determined at 1.30-angstrom resolution. Comparison between SRX and SFX structures revealed that photoreduction changes the coordination manner of the substrate and that catalytically important His255 can switch hydrogen bond partners between the backbone carbonyl oxygen of nearby Glu279 and the side-chain hydroxyl group of Thr280. These findings, which SRX has failed to uncover, propose a redox-coupled proton switch for PCET. This concept can explain how proton transfer to the substrate is involved in intramolecular electron transfer and why substrate binding accelerates PCET. Our study demonstrates the potential of SFX as a powerful tool to study redox processes in metalloenzymes.</P>