• Biomolecules & Therapeutics
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• 제30권2호
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• pp.162-169
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• 2022

We utilized Fas21, a resveratrol analog, to modulate the function of hepatic stellate cells (HSCs) and liver sinusoidal endothelial cells (LSECs) during the angiogenic phase of murine liver metastasis by B16 melanoma and 51b colorectal carcinoma. Preangiogenic micrometastases were treated with Fas21 (1 mg/kg/day) or vehicle during the development of intra-angiogenic tracts. Mice treated with Fas21 showed reduced liver tumor foci in both liver metastasis models. Micrometastases were classified immunohistochemically, as well as according to their position coordinates and connection to local microvasculature. The volume of liver occupied by sinusoidal-type foci, containing infiltrating angiogenic capillaries, decreased by ~50% in Fas21-treated mice compared to vehicle-treated ones in both tumor metastasis models. The volume of portal foci, containing peripheral neoangiogenesis within a discontinuous layer of myofibroblasts, was similar in all experimental groups in both tumor metastasis models, but displayed enhanced necrotic central areas devoid of angiogenesis following Fas21 treatment. As a result, sinusoidal tumors from mice treated with Fas21 showed a 50% reduction in desmin(+)/asma(+) HSCs and CD31(+) vessel density, and a 45% reduction in intrametastatic VEGF mRNA compared with sinusoidal tumors from vehicle-treated mice. Necrotic portal metastases increased 2-4-fold in treated mice. In vitro, Fas21 reduced VEGF secretion by HSCs and 51b cells dose-dependently. Additionally, HSCs migration in response to tumor soluble factors was dose-dependently diminished by Fas21, as was LSEC migration in response to HSCs and tumor soluble factors. Resveratrol analog Fas21 inhibits the proangiogenic response of HSCs and LSECs during the development of murine liver metastasis.

• Journal of the Korean Data and Information Science Society
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• 제28권1호
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• pp.29-37
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• 2017

산림경영 계획을 위한 필요한 산림재적을 보다 효율적으로 추정하기 위해서 다양한 연구가 요구되어져 왔는데, 이러한 산림구조에 관한 연구는 주로 현장조사와 위성영상을 이용하여 이루어진다. 현장조사를 통한 연구는 비교적 정확하나 시간과 비용이 많이 들 뿐 아니라 접근의 용이성이 떨어지는 지역이 있기 때문에, 넓은 지역의 조사가 어렵다는 단점이 있다. 최근에는 항공기에서 발사된 레이저 펄스가 반사되어 돌아오는 시간을 측정하여 대상의 3차원 좌표를 얻는 LiDAR (Light Detection and Ranging) 기술을 활용하여 획득한 정밀한 수치형자료를 이용한 산림의 구조에 관한 연구가 이루어지고 있다. 일반적으로 산림재적을 추정하기 위해서 LiDAR자료를 이용한 수고자료와 산림 재적에 대한 회귀모형의 중요성이 점차 높아지는데, 국내의 경우 수목의 종류와 그 분포가 다르기 때문에 회귀모형만으로 재적을 추정하는 데 한계가 있다. 따라서 본 논문에서는 산림의 수고와 흉고직경을 측정하여 재적값을 추정하고 산림의 공간효과를 고려한 계층적 베이지안 분석을 통해 관측되지 않은 전체 산림재적에 대한 추정을 하고자 한다.

• 말소리와 음성과학
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• 제1권3호
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• pp.151-154
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• 2009

The external ear generates resonance gain because of anatomical characteristics. The ear canal resonance is influenced by the length and volume of the ear canal, the pinna, the concha cavity, the body trunk, and the speed of sound wave. This study is focus on the influence of the volume of ear canal. 17-healthy-adult (32 ears) were participated. They did not have any medical and ear disease history. The maximum resonance frequency of the ear canal was 2675 (${\pm}265$) Hz at azimuth $0^{\circ}$ and 2784 (${\pm}268$) Hz at azimuth $45^{\circ}$. The resonance gain was 18.1 (${\pm}3.9$) dB at azimuth $0^{\circ}$ and 17.9 (${\pm}3.8$) dB at azimuth $45^{\circ}$, respectively. The ear canal volume was 0.78 (${\pm}0.2$) cc and 1.32 (${\pm}0.8$) cc including static compliance. The ear canal resonance was changed depending on the ear canal volume. It was also statistically correlated at azimuth $0^{\circ}$ (p=0.038) and $45^{\circ}$ (p=0.013), respectively. The resonance gain was not correlated with the ear canal volume. The change of resonance frequency according to the ear canal volume will be useful information in the field of audiological rehabilitation especially for hearing aids fitting. In addition, we expected this study can provide the basic information for the study of the external ear resonance characteristics.

• 한국임상약학회지
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• 제9권1호
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• pp.15-18
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• 1999

Ascertainment of accurate pharmacokinetic parameters for aminoglycoside dosing remains critical, as the serum drug concentration relates directly to both the therapeutic response and toxic effect. In the initial dosing of aminoglycosides, the volume of distribution is especially important because the dosage is calculated by multiplying the volume of distribution by the desired serum concentration. Aminoglycosides distribute into mainly the extracellular fluid and it has been reported that the volume of distribution is 0.25 L/kg. Penetration of polar aminoglycosides into adipose tissue occurs to some extent, but varies according to the degree of obesity. Therefore, dosages may be overestimated or underestimated according to the type of the dosing weight in overweight or underweight patients. Prior investigations have suggested various dosing weights which are multiplied by the popular volume of distribution to calculate the total volume of distribution. Based on other investigations, we calculated a new dosing weight which was applicable to all patients regardless of obesity in order to use the popular volume of distribution. We estimated IBW+$0.414^{\ast}$(TBW-IBW) as a new dosing weight with the SAS program. A new dosing weight is similar to those of other studies which examined in morbidly obese patients. Consequently we suggests that the dosing weight reported in morbidly obese patients can be extended to a broader patients population. But we found that the volume of distribution per kilogram from our patients was significantly larger than that for foreign patients(0.343L/kg vs 0.25 L/kg)(Kor. J. Clin. Pharm. 1999; 9(1): 15-18)

• Korean Circulation Journal
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• 제53권6호
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• pp.406-417
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• 2023

Background and Objectives: Pathophysiological changes of right ventricle (RV) after repair of tetralogy of Fallot (TOF) are coupled with a highly compliant low-pressure pulmonary artery (PA) system. This study aimed to determine whether pulmonary vascular function was associated with RV parameters and exercise capacity, and its impact on RV remodeling after pulmonary valve replacement. Methods: In a total of 48 patients over 18 years of age with repaired TOF, pulmonary arterial elastance (Ea), RV volume data, and RV-PA coupling ratio were calculated and analyzed in relation to exercise capacity. Results: Patients with a low Ea showed a more severe pulmonary regurgitation volume index, greater RV end-diastolic volume index, and greater effective RV stroke volume (p=0.039, p=0.013, and p=0.011, respectively). Patients with a high Ea had lower exercise capacity than those with a low Ea (peak oxygen consumption [peak VO₂] rate: 25.8±7.7 vs. 34.3±5.5 mL/kg/min, respectively, p=0.003), while peak VO₂ was inversely correlated with Ea and mean PA pressure (p=0.004 and p=0.004, respectively). In the univariate analysis, a higher preoperative RV end-diastolic volume index and RV end-systolic volume index, left ventricular end-systolic volume index, and higher RV-PA coupling ratio were risk factors for suboptimal outcomes. Preoperative RV volume and RV-PA coupling ratio reflecting the adaptive PA system response are important factors in optimal postoperative results. Conclusions: We found that PA vascular dysfunction, presenting as elevated Ea in TOF, may contribute to exercise intolerance. However, Ea was inversely correlated with pulmonary regurgitation (PR) severity, which may prevent PR, RV dilatation, and left ventricular dilatation in the absence of significant pulmonary stenosis.

• 한국추진공학회지
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• 제13권1호
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• pp.19-26
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• 2009

과산화수소 단일추진제 추력기의 응답성에 대한 실험적 연구를 수행하였다. 촉매베드의 특성을 배제하고 추력기 설계 인자에 따른 응답특성을 살펴보기 위해 $MnO_2$/$Al_2O_3$를 주 촉매로 고정하였다. 세 가지 50 N 급 추력기를 이용하여 인젝터 방식, ullage volume, 촉매 펠렛 크기, 반응기 부피에 따른 응답 속도를 측정하였다. 측정 결과 16-20 mesh 크기 촉매, shower head 인젝터를 사용한 경우 점화지연, 압력 상승 및 하강시간은 각각 14, 108, 94 ms로 상용 하이드라진 추력기 응답성에 근접한 특성을 보였다.

• Nuclear Engineering and Technology
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• 제50권3호
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• pp.439-445
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• 2018

Experimental measurements of the response of $BF_3$ detector to a 3 Ci Am-Be neutron source for three different reflecting materials, i.e., aluminum, wood, and Perspex of varying thicknesses have been carried out. The varying contribution of wall effect to the response due to change in active volume of the detector has also been determined experimentally. Then, a Monte Carlo code has been developed for the calculation of the neutron response function of the $BF_3$ detector using source biasing and importance sampling. This code simulates the $BF_3$ detector response exposed to the neutron field in a three-dimensional source, detector, and reflecting medium configurations. The results of simulation have been compared with the corresponding experimental measurements and are found to be in good agreement. The experimental neutron albedo measurements for various values of Perspex thickness show saturating behavior, and results agree very well with the data obtained by Monte Carlo simulation.

• The Korean Journal of Physiology and Pharmacology
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• 제4권3호
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• pp.253-261
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• 2000

Head-out water immersion induces marked increase in the cardiac stroke volume. The present study was undertaken to characterize the stroke volume change by analyzing the aortic blood flow and left ventricular systolic time intervals. Ten men rested on a siting position in the air and in the water at $34.5^{circ}C$ for 30 min each. Their stroke volume, heart rate, ventricular systolic time intervals, and aortic blood flow indices were assessed by impedance cardiography. During immersion, the stroke volume increased 56%, with a slight (4%) decrease in heart rate, thus cardiac output increased ${\sim}50%.$ The slight increase in R-R interval was due to an equivalent increase in the systolic and diastolic time intervals. The ventricular ejection time was 20% increased, and this was mainly due to a decrease in pre-ejection period (28%). The mean arterial pressure increased 5 mmHg, indicating that the cardiac afterload was slightly elevated by immersion. The left ventricular end-diastolic volume index increased 24%, indicating that the cardiac preload was markedly elevated during immersion. The mean velocity and the indices of peak velocity and peak acceleration of aortic blood flow were all increased by ${\sim}30%,$ indicating that the left ventricular contractile force was enhanced by immersion. These results suggest that the increase in stroke volume during immersion is characterized by an increase in ventricular ejection time and aortic blood flow velocity, which may be primarily attributed to the increased cardiac preload and the muscle length-dependent increase in myocardial contractile force.

• 산업경영시스템학회지
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• 제43권4호
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• pp.15-22
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• 2020

Economic indicators are a factor that affects air cargo volume. This study analyzes the different factors affecting air cargo volume by each Chinese cities according to the main characteristics. The purpose of this study is to help companies related to China, airlines, and other stakeholders predict and prepare for the fluctuations in air cargo volume and make optimal decisions. To this end, 20 economic data were used, and the entire data was reduced to 5 dimensions through factor analysis to build a dataset necessary and evaluated the influencing factors by multi regression. The result shows that Macro-Economic Indicators, Production/Service indicators are significant for every cities and Chinese manufacture/Customer indicators, Korean manufacture/Oil Price indicators, Trade/Current indicators are significant for each other city. All adjusted R2 values are high enough to explain our model and the result showed excellent performance in terms of analyzing the different factors which affects air cargo volume. If companies that are currently doing business with China can identify factors affecting China's cargo volume, they can be flexible in response to changes in plans such as plans to enter China, production plans and inventory management, and marketing strategies, which can be of great help in terms of corporate operations.

• Radiation Oncology Journal
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• 제35권2호
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• pp.180-184
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• 2017

Patients with locally advanced lung cancer and very limited pulmonary function (forced expiratory volume in 1 second $[FEV1]{\leq}1L$) have dismal prognosis and undergo palliative treatment or best supportive care. We describe two cases of locally advanced node-positive non-small cell lung cancer (NSCLC) patients with very limited lung function treated with induction chemotherapy and moderate hypofractionated image-guided radiotherapy (Hypo-IGRT). Hypo-IGRT was delivered to a total dose of 45 Gy to the primary tumor and involved lymph nodes. Planning was based on positron emission tomography-computed tomography (PET/CT) and four-dimensional computed tomography (4D-CT). Internal target volume (ITV) was defined as the overlap of gross tumor volume delineated on 10 phases of 4D-CT. ITV to planning target volume margin was 5 mm in all directions. Both patients showed good clinical and radiological response. No relevant toxicity was documented. Hypo-IGRT is feasible treatment option in locally advanced node-positive NSCLC patients with very limited lung function ($FEV1{\leq}1L$).