• Nuclear Engineering and Technology
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• 제56권1호
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• pp.106-113
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• 2024

Understanding the tritium release and retention behavior of candidate tritium breeder materials is crucial for breeder blanket design. Recently, a melt spraying process was developed to prepare Li₄SiO₄ pebbles, which were subsequently subjected to the in-pile tritium production and extraction platform in China Mianyang Research Reactor (CMRR) to investigate their in-situ tritium release behavior and irradiation performance. The results demonstrate that HT is the main tritium release form, and adding hydrogen to the purge gas reduces tritium retention while increasing the HT percent in the purge gas. Post-irradiation experiments reveal that the irradiated pebbles darken in color and their grains swell, but the mechanical properties remain largely unchanged. It is concluded that the tritium residence time of Li₄SiO₄ made by melt spraying method at 467 ℃ is approximately 23.34 h. High-density Li₄SiO₄ pebbles exhibit tritium release at relatively low temperatures (<600 ℃) that is mainly controlled by bulk diffusion. The diffusion coefficient at 525 ℃ and 550 ℃ is 1.19 × 10^-11 cm²/s and 5.34 × 10^-11 cm²/s, respectively, with corresponding tritium residence times of 21.3 hours and 4.7 hours.

• 경영정보학연구
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• 제20권2호
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• pp.209-226
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• 2018

위치기반 서비스는 데스크톱 기반에서 활용하던 과거의 온라인 커머스(Online Commerce)와는 차별적인 서비스 특성을 지닌다. 장소에 상관없이 이동 통신 기기를 활용하여 온라인에 접속하여 온라인 쇼핑을 활용할 수 있으며, 보다 편하게 사용자의 편의를 보장해준다. 위치 별로 특정적인 쇼핑 정보, 서비스 정보를 제공함으로써, 소비자에게 위치에 따른 편익을 제공할 수 있게 되었다. 또한 위치뿐만 아니라 다양한 희소성 정보를 제공함으로써, 소비자의 구매 욕구를 증대 시키게 된다. 본 연구에서는 위치기반 서비스에서 희소성의 제공 단계에 따라 소비자의 구매의도 변화에 어떤 영향을 주는지에 대하여 연구하였다. 희소성의 단계는 첫째, 희소성이 없는 단계, 둘째, 시간제한 정보를 제공하는 단계, 셋째, 수량 제한 정보를 제공하는 단계, 넷째, 시간, 수량 제한을 제공하는 단계로 실험 설계하여 실험 자극물을 통한 4집단 분석을 진행하였다. 위치기반 서비스의 특성인 편재성과 상호작용성, 프라이버시 염려의 변수들을 추가하여 희소성의 단계에 따른 종속변수의 영향력 차이에 대하여 확인하고자 하였다. 분석결과, 시간제한과 수량 제한 희소성 자극물은 편재성, 상호작용성과 소비자의 구매의도에 조절 효과를 나타냈으며, 해당 변수들도 직간접적으로 긍정적 영향을 주었다. 프라이버시 염려는 소비자의 구매의도에 부정적인 영향을 주는 것으로 확인하였다.

• Korean Journal of Radiology
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• 제20권4호
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• pp.621-630
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• 2019

Objective: To study the prevalence and clinical characteristics of decreased myocardial blood flow (MBF) quantified by dynamic computed tomography (CT) myocardial perfusion imaging (MPI) in symptomatic patients without in-stent restenosis. Materials and Methods: Thirty-seven (mean age, 71.3 ± 10 years; age range, 48-88 years; 31 males, 6 females) consecutive symptomatic patients with patent coronary stents and without obstructive de novo lesions were prospectively enrolled to undergo dynamic CT-MPI using a third-generation dual-source CT scanner. The shuttle-mode acquisition technique was used to image the complete left ventricle. A bolus of contrast media (50 mL; iopromide, 370 mg iodine/mL) was injected into the antecubital vein at a rate of 6 mL/s, followed by a 40-mL saline flush. The mean MBF value and other quantitative parameters were measured for each segment of both stented-vessel territories and reference territories. The MBF_ratio was defined as the ratio of the mean MBF value of the whole stent-vessel territory to that of the whole reference territory. An MBF_ratio of 0.85 was used as the cut-off value to distinguish hypoperfused from non-hypoperfused segments. Results: A total of 629 segments of 37 patients were ultimately included for analysis. The mean effective dose of dynamic CT-MPI was 3.1 ± 1.2 mSv (range, 1.7-6.3 mSv). The mean MBF of stent-vessel territories was decreased in 19 lesions and 81 segments. Compared to stent-vessel territories without hypoperfusion, the mean MBF and myocardial blood volume were markedly lower in hypoperfused stent-vessel territories (77.5 ± 16.6 mL/100 mL/min vs. 140.4 ± 24.1 mL/100 mL/min [p < 0.001] and 6.4 ± 3.7 mL/100 mL vs. 11.5 ± 4 mL/100 mL [p < 0.001, respectively]). Myocardial hypoperfusion in stentvessel territories was present in 48.6% (18/37) of patients. None of clinical parameters differed statistically significantly between hypoperfusion and non-hypoperfusion subgroups. Conclusion: Decreased MBF is commonly present in patients who are symptomatic after percutaneous coronary intervention, despite patent stents and can be detected by dynamic CT-MPI using a low radiation dose.

• Korean Journal of Radiology
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• 제20권5호
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• pp.709-718
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• 2019

Objective: To investigate the association of myocardial blood flow (MBF) quantified by dynamic computed tomography (CT) myocardial perfusion imaging (MPI) with troponin level and left ventricle (LV) function in patients with ST-segment elevated myocardial infarction (STEMI). Materials and Methods: Thirty-five STEMI patients who successfully had undergone reperfusion treatment within 1 week of their infarction were consecutively enrolled. All patients were referred for dynamic CT-MPI. Serial high-sensitivity troponin T (hs-TnT) levels and left ventricular ejection fraction (LVEF) measured by echocardiography were recorded. Twenty-six patients with 427 segments were included for analysis. Various quantitative parameters derived from dynamic CT-MPI were analyzed to determine if there was a correlation between hs-TnT levels and LVEF on admission and again at the 6-month mark. Results: The mean radiation dose for dynamic CT-MPI was 3.2 ± 1.1 mSv. Infarcted territories had significantly lower MBF (30.5 ± 7.4 mL/min/100 mL versus 73.4 ± 8.1 mL/min/100 mL, p < 0.001) and myocardial blood volume (MBV) (2.8 ± 0.9 mL/100 mL versus 4.2 ± 1.1 mL/100 mL, p = 0.044) compared with those of reference territories. MBF showed the best correlation with the level of peak hs-TnT (r = -0.682, p < 0.001), and MBV showed a moderate correlation with the level of peak hs-TnT (r = -0.437, p = 0.026); however, the other parameters did not show any significant correlation with hs-TnT levels. As for the association with LV function, only MBF was significantly correlated with LVEF at the time of admission (r = 0.469, p = 0.016) and at 6 months (r = 0.585, p = 0.001). Conclusion: MBF quantified by dynamic CT-MPI is significantly inversely correlated with the level of peak hs-TnT. In addition, patients with lower MBF tended to have impaired LV function at the time of their admission and at 6 months.

• Animal Bioscience
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• 제37권8호
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• pp.1483-1494
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• 2024

Objective: This study was conducted to investigate the effect of slaughter age on carcass traits, meat quality, and the relative mRNA levels of lipid metabolism-related genes in different muscles of Taihang black goats. Methods: In this study, the triceps brachii (TB), longissimus dorsi (LD) and gluteus (GL) muscles of 15 grazing Taihang black goats slaughtered at the age of 2, 3, and 4 (designated as 2-year-old, 3-year-old, and 4-year-old, respectively) were collected. The differences in carcass shape, meat quality, amino acid composition and lipid metabolism gene expression among Taihang black goats of different ages and from different plant parts were compared. Results: Compared with goats at other ages, goats slaughtered at the age of 4 had greater live and carcass weights, meat weights, bone weights and skin areas (p<0.05). LD in the 4-years-old had the lowest cooking loss and moisture content. The crude protein content in the LD of 2-year-old was significantly greater than that in the other age group, and at the age of 2, the LD had the highest crude protein content than TB and GL. The highest fat content was in LD, followed by TB, for goats slaughtered at the age of 4. Eight out of 9 essential amino acids had higher content in the TB compared with other muscles, regardless of age. The total essential amino acid content was highest in the 4-year-old and lowest in the GL muscle at the age of 3. The sterol regulatory element-binding protein-1c (SREBP-1c) and adipose triglyceride lipase (ATGL) genes were significantly more abundant in the TB muscle than in the other muscles for goats slaughtered at the age of 2. At the age of 4, the ATGL and peroxisome proliferator-activated receptor γ (PPARγ) genes were significantly more abundant in the GL than in the LD, while the fatty acid synthase (FAS) genes were significantly less abundant in the GL than in the other muscles. Similarly, compared with those in goats of other ages, the relative mRNA expression levels of the FAS and heart-type fatty acid binding protein (H-FABP) genes in goats slaughtered at the age of 4 were the highest, and the relative mRNA expression of the PPARγ gene was the lowest (p<0.05). The relative mRNA expression of the H-FABP and FAS genes was positively correlated with the intramuscular fat (IMF) content, while the relative mRNA expression levels of the PPARγ and ATGL genes was negatively correlated with the IMF content. Conclusion: Overall, a better nutritional value was obtained for TB from 4-year-old goats, in which the total essential amino acid and fat contents were greater than those of other muscles. The comprehensive action of lipid metabolism genes was consistent with that of the IMF content, among which the FAS, H-FABP, PPARγ, and ATGL genes had positive and negative effects on the process of IMF deposition in Taihang black goats.

• Geomechanics and Engineering
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• 제37권6호
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• pp.599-614
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• 2024

To evaluate the safety status of deteriorated segments in a submarine shield tunnel during its service life, a seepage model was established based on a cross-sea shield tunnel project. This model was used to study the migration patterns of erosive ions within the shield segments. Based on these laws, the degree of deterioration of the segments was determined. Using the derived analytical solution, the internal forces within the segments were calculated. Lastly, by applying the formula for calculating safety factors, the variation trends in the safety factors of segments with different degrees of deterioration were obtained. The findings demonstrate that corrosive seawater presents the evolution characteristics of continuous seepage from the outside to the inside of the tunnel. The nearby seepage field shows locally concentrated characteristics when there is leakage at the joint, which causes the seepage field's depth and scope to significantly increase. The chlorine ion content decreases gradually with the increase of the distance from the outer surface of the tunnel. The penetration of erosion ions in the segment is facilitated by the presence of water pressure. The ion content of the entire ring segment lining structure is related in the following order: vault < haunch < springing. The difference in the segment's rate of increase in chlorine ion content decreases as service time increases. Based on the analytical solution calculation, the segment's safety factor drops more when the joint leaks than when its intact, and the change rate between the two states exhibits a general downward trend. The safety factor shows a similar change rule at different water depths and continuously decreases at the same segment position as the water depth increases. The three phases of "sudden drop-rise-stability" are represented by a "spoon-shaped" change rule on the safety factor's change curve. The issue of the poor applicability of indicators in earlier studies is resolved by the analytical solution, which only requires determining the loss degree of the segment lining's effective bearing thickness to calculate the safety factor of any cross-section of the shield tunnel. The analytical solution's computation results, however, have some safety margins and are cautious. The process of establishing the evaluation model indicates that the secondary lining made of molded concrete can also have its safety status assessed using the analytical solution. It is very important for the safe operation of the tunnel and the safety of people's property and has a wide range of applications.

• Animal Bioscience
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• 제37권7호
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• pp.1236-1245
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• 2024

Objective: The object of this study was to investigate the effect of replacing soybean meal with Clostridium autoethanogenum protein (CAP) in broiler diets on growth performance, blood indicators, antioxidant capacity, and immune function. Methods: A total of 180 Arbor Acres broilers were randomly divided into three treatments, each treatment with six replicates and 10 broilers per replicate for a 42-day feeding trial. The control group (CON) was fed corn-soybean meal based diet. The CAP-1 and CAP-2 groups were considered to use CAP to replace 25% or 50% of soybean meal in the diet, respectively. The average daily gain and average daily feed intake of broilers at 1 to 21 d, 22 to 42 d, and 1 to 42 d were measured, and the feed conversion ratio was calculated. At the 42nd day of age, two broilers with similar weights and fasted for 12 h were selected in each replicate for blood collection from the brachial wing vein. The blood routine indicators, serum biochemical indicators, serum antioxidant capacity, and immunoglobulin content of broiler chickens were measured. Results: Replacement of soybean meal with 25% (CAP-1) and 50% (CAP-2) CAP significantly increased the average daily gain of 22 to 42 d and 1 to 42 d and decreased the average daily feed intake and feed conversion rate (p<0.05). The CAP-1 group, and CAP-2 group significantly increased hemoglobulin in the blood of broilers, while the CAP-2 group increased hematocrit content (p<0.05). Compared with the control group, the contents of superoxide dismutase and immunoglobulin A in serum of the CAP-2 group were significantly increased, while the contents of malondialdehyde in CAP group were significantly decreased (p<0.05). Conclusion: Replacing soybean meal with CAP led to significant improvements in the growth performance, antioxidant capacity, and immunoglobulin content of broilers.

• Korean Journal of Radiology
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• 제20권4호
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• pp.641-648
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• 2019

Objective: The purpose of this study was to investigate whether three-dimensional (3D) magnetic resonance imaging could improve diagnostic accuracy for suspected posterior ligamentous complex (PLC) disruption. Materials and Methods: We used 20 freshly harvested goat spine samples with 60 segments and intact surrounding soft tissue. The animals were aged 1-1.5 years and consisted of 8 males and 12 females, which were sexually mature but had not reached adult weights. We created a paraspinal contusion model by percutaneously injecting 10 mL saline into each side of the interspinous ligament (ISL). All segments underwent T2-weighted sagittal and coronal short inversion time inversion recovery (STIR) scans as well as coronal and sagittal 3D proton density-weighted spectrally selective inversion recovery (3D-PDW-SPIR) scans acquired at 1.5T. Following scanning, some ISLs were cut and then the segments were rescanned using the same magnetic resonance (MR) techniques. Two radiologists independently assessed the MR images, and the reliability of ISL tear interpretation was assessed using the kappa coefficient. The chi-square test was used to compare the diagnostic accuracy of images obtained using the different MR techniques. Results: The interobserver reliability for detecting ISL disruption was high for all imaging techniques (0.776-0.949). The sensitivity, specificity, and diagnostic accuracy of the coronal 3D-PDW-SPIR technique for detecting ISL tears were 100, 96.9, and 97.9%, respectively, which were significantly higher than those of the sagittal STIR (p = 0.000), coronal STIR (p = 0.000), and sagittal 3D-PDW-SPIR (p = 0.001) techniques. Conclusion: Compared to other MR methods, coronal 3D-PDW-SPIR provides a more accurate diagnosis of ISL disruption. Adding coronal 3D-PDW-SPIR to a routine MR protocol may help to identify PLC disruptions in cases with nearby contusion.

• International Journal of Stem Cells
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• 제16권1호
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• pp.52-65
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• 2023

Background and Objectives: Epithelial-Mesenchymal transition (EMT) is one of the origins of myofibroblasts in renal interstitial fibrosis. Mesenchymal stem cells (MSCs) alleviating EMT has been proved, but the concrete mechanism is unclear. To explore the mechanism, serum-free MSCs conditioned medium (SF-MSCs-CM) was used to treat rat renal tubular epithelial cells (NRK-52E) fibrosis induced by transforming growth factor-β1 (TGF-β1) which ameliorated EMT. Methods and Results: Galectin-3 knockdown (Gal-3 KD) and overexpression (Gal-3 OE) lentiviral vectors were established and transfected into NRK-52E. NRK-52E fibrosis model was induced by TGF-β1 and treated with the SF-MSCs-CM for 24 h after modelling. Fibrosis and autophagy related indexes were detected by western blot and immunocytochemistry. In model group, the expressions of α-smooth muscle actin (α-SMA), fibronectin (FN), Galectin-3, Snail, Kim-1, and the ratios of P-Akt/Akt, P-GSK3β/GSK3β, P-PI3K/PI3K, P-mTOR/mTOR, TIMP1/MMP9, and LC3B-II/I were obviously increased, and E-Cadherin (E-cad) and P62 decreased significantly compared with control group. SF-MSCs-CM showed an opposite trend after treatment compared with model group. Whether in Gal-3 KD or Gal-3 OE NRK-52E cells, SF-MSCs-CM also showed similar trends. However, the effects of anti-fibrosis and enhanced autophagy in Gal-3 KD cells were more obvious than those in Gal-3 OE cells. Conclusions: SF-MSCs-CM probably alleviated the EMT via inhibiting Galectin-3/Akt/GSK3β/Snail pathway. Meanwhile, Gal-3 KD possibly enhanced autophagy via inhibiting Galectin-3/Akt/mTOR pathway, which synergistically ameliorated renal fibrosis. Targeting galectin-3 may be a potential target for the treatment of renal fibrosis.

• Journal of Microbiology and Biotechnology
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• 제34권6호
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• pp.1287-1298
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• 2024

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that is currently difficult to treat effectively. Both Bacillus natto (BN) and ginseng-soluble dietary fiber (GSDF) are anti-inflammatory and helps sustain the intestinal barrier. In this study, the protective effects and mechanism of the combination of B. natto JLCC513 and ginseng-soluble dietary fiber (BG) in DSS-induced UC mice were investigated. Intervention with BG worked better than taking BN or GSDF separately, as evidenced by improved disease activity index, colon length, and colon injury and significantly reduced the levels of oxidative and inflammatory factors (LPS, ILs, and TNF-α) in UC mice. Further mechanistic study revealed that BG protected the intestinal barrier integrity by maintaining the tight junction proteins (Occludin and Claudin1) and inhibited the LPS/TLR4/NF-κB pathway in UC mice. In addition, BG increased the abundance of beneficial bacteria such as Bacteroides and Turicibacter and reduced the abundance of harmful bacteria such as Allobaculum in the gut microbiota of UC mice. BG also significantly upregulated genes related to linoleic acid metabolism in the gut microbiota. These BG-induced changes in the gut microbiota of mice with UC were significantly correlated with changes in pathological indices. In conclusion, this study demonstrated that BG exerts protective effect against UC by regulating the LPS/TLR4/NF-κB pathway and the structure and metabolic function of gut microbiota. Thus, BG can be potentially used in intestinal health foods to treat UC.