• Title/Summary/Keyword: Medical Engineering

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Joint Relay Selection and Resource Allocation for Delay-Sensitive Traffic in Multi-Hop Relay Networks

  • Sha, Yan;Hu, Jufeng;Hao, Shuang;Wang, Dan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.9
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    • pp.3008-3028
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    • 2022
  • In this paper, we investigate traffic scheduling for a delay-sensitive multi-hop relay network, and aim to minimize the priority-based end-to-end delay of different data packet via joint relay selection, subcarrier assignment, and power allocation. We first derive the priority-based end-to-end delay based on queueing theory, and then propose a two-step method to decompose the original optimization problem into two sub-problems. For the joint subcarrier assignment and power control problem, we utilize an efficient particle swarm optimization method to solve it. For the relay selection problem, we prove its convexity and use the standard Lagrange method to deal with it. The joint relay selection, subcarriers assignment and transmission power allocation problem for each hop can also be solved by an exhaustive search over a finite set defined by the relay sensor set and available subcarrier set. Simulation results show that both the proposed routing scheme and the resource allocation scheme can reduce the average end-to-end delay.

Radiation dosimetry of 89Zr labeled antibody estimated using the MIRD method and MCNP code

  • Saeideh Izadi Yazdi ;Mahdi Sadeghi ;Elham Saeedzadeh ;Mostafa Jalilifar
    • Nuclear Engineering and Technology
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    • v.55 no.4
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    • pp.1265-1268
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    • 2023
  • One important issue in using radiopharmaceuticals as therapeutic and imaging agents is predicting different organ absorbed dose following their injection. The present study aims at extrapolating dosimetry estimates to a female phantom from the animal data of 89Zr radionuclide accumulation using the Sparks-Idogan relationship. The absorbed dose of 89Zr radionuclide in different organs of the human body was calculated based on its distribution data in mice using both MIRD method and the MCNP simulation code. In this study, breasts, liver, heart wall, stomach, kidneys, lungs and spleen were considered as source and target organs. The highest and the lowest absorbed doses were respectively delivered to the liver (4.00E-02 and 3.43E-02 mGy/MBq) and the stomach (1.83E-03 and 1.66E-03 mGy/MBq). Moreover, there was a good agreement between the results obtained from both MIRD and MCNP methods. Therefore, according to the dosimetry results, [89Zr] DFO-CR011-PET/CT seems to be a suitable for diagnostic imaging of the breast anomalies for CDX-011 targeting gpNMB in patients with TNBC in the future.

The Preventive Effects of Paeoniae Radix Extract against LPS-induced Acute Hepatotoxicity (LPS로 유도된 급성 간독성에 대한 백작약 추출물의 보호 효과)

  • Kim, In-Deok;Kwon, Ryun-Hee;Heo, Ye-Young;Lee, Dong-Geun;Lee, Jae-Hwa;Lee, Sang-Hyeon;Ha, Jong-Myung;Ha, Bae-Jin
    • Journal of Food Hygiene and Safety
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    • v.23 no.3
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    • pp.222-226
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    • 2008
  • The purpose of this study was to investigate the preventive effects of Paeoniae Radix Extract(PRE) against the acute hepatotoxicity-inducing lipopolysaccharide(LPS) in the liver. PRE of 100 mg/kg concentration was intraperitoneally administered into rats at dose of 1.5 ml/kg for 20 days. On day 21, 5 mg/kg of LPS dissolved in saline was injected 4 hours before anesthetization. We examined the levels of glutamate oxaloacetate transaminase(GOT), glutamate pyruvate transaminase(GPT), lactate dehydrogenase(LDH) in serum of rats, superoxide dismutase(SOD) in mitochondrial fractions, and malondialdehyde(MDA), catalase(CAT), glutathione peroxidase(GPx) in liver homogenates. LPS-treatment markedly increased the levels of GOT, GPT, LDH and MDA, and significantly decreased those of SOD, CAT and GPx. But PRE-pretreatment decreased the levels of GOT, GPT, LDH and MDA, by 59.7%, 43.6%, 59.6% and 63.5%, respectively and increased those of SOD, CAT and GPx, by 85.5%, 57.8% and 62.9%, respectively. These results showed that the PRE had the preventive effects against the acute hepatotoxicity-inducing LPS in the liver.

A Study of the Effect of Acoustic Noise Attenuator on Auditory Functional MRI (소음 감쇠기를 이용한 청각의 뇌기능 자기공명영상)

  • Kim, S.H.;Kim, I.S.;Lee, J.J.;Park, J.A.;Lee, Y.J.;Yeo, J.R.;Bae, S.J.;Lee, S.H.;Chang, Y.
    • Investigative Magnetic Resonance Imaging
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    • v.9 no.2
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    • pp.134-139
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    • 2005
  • Purpose : To evaluate the usefulness of acoustic noise attenuator on auditory fMRI examination. Materials and methods : The acoustic noise attenuator consists of mask, earmuff and silicon earplug. The soft polyurethane sheet and polyurethane form , which has a good soundproof characteristic were used for mask and earmuff. Auditory fMRI experiments of 500 Hz pure tone stimulation were performed in three different cases; first all of mask, earmuff and earplug, secondly earmuff and earplug only and finally without attenuator in 4 normal hearing volunteers. For data acquisition, BOLD MR imaging technique was employed at a 1.5T MR scanner equipped with high performance gradient system. The raw data were analyzed using a SPM-99 analysis software and the activation maps were obtained. Results : In case of all items of acoustic attenuator used, the results revealed that activation was focused on primary auditory area. When only earmuff and earplug were used, the results showed that the activation spread over primary auditory and secondary associative areas. Last, when no device used, only weak activation was observed on the right auditory cortex. Conclusion : It is expected that the acoustic noise attenuator, which consists of earplugs, earmuffs and mask, is a very useful device in auditory fMRI study.

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The Effect of Inhibition of Uncaria rhynchophylla as an Inhibitor of Melanogenesis and an Antioxidant in B16F10 Melanoma Cells (B16F10세포에서 멜라닌 생성 억제제 및 항산화제로서 조구등의 억제 효과)

  • Dong, Yuanyuan;Woo, Young Min;Cha, Ji Hyun;Cha, Jae Young;Lee, Nai Wei;Back, Min Woo;Park, Joon-sung;Lee, Sang-Hyeon;Ha, Jong-Myung;Kim, Andre
    • Journal of Life Science
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    • v.30 no.12
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    • pp.1033-1041
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    • 2020
  • Many people of all ages wish to have lighter skin for cosmetic reasons, and natural products attract more attention than chemically synthesized compounds. Uncaria rhynchophylla is widely used in Asia as a traditional herbal medicine. In order to find novel skin whitening agents, the present study evaluated the antioxidant activity and potential tyrosinase-inhibiting properties of U. rhynchophylla. Specifically, this study analyzed the antioxidant capacity of a 70% ethanolic extract of U. rhynchophylla as well as its effects on tyrosinase activity and melanin synthesis. Total mRNA levels were examined using reverse transcription polymerase chain reaction. The results revealed that U. rhynchophylla extracts exhibit great antioxidant capacity and significant levels of polyphenol and flavonoid compounds. U. rhynchophylla extracts can also powerfully inhibit tyrosinase activity. This same capacity was observed in melanoma B16F10 cells; that is, U. rhynchophylla extracts suppressed intracellular tyrosinase activity and reduced the amount of melanin in treated cells. In addition, a 1 mg/ml concentration of U. rhynchophylla extract significantly reduced the mRNA expression levels of tyrosinase. U. rhynchophylla extracts decrease tyrosinase and inhibit melanogenesis in B16F10 cells. This finding suggests that U. rhynchophylla has great potential as a natural whitening agent in skincare products.

Segmentation and 3D Visualization of Medical Image : An Overview

  • Kang, Jiwoo;Kim, Doyoung;Lee, Sanghoon
    • Journal of International Society for Simulation Surgery
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    • v.1 no.1
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    • pp.27-31
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    • 2014
  • In this paper, an overview of segmentation and 3D visualization methods are presented. Commonly, the two kinds of methods are used to visualize organs and vessels into 3D from medical images such as CT(A) and MRI - Direct Volume Rendering (DVR) and Iso-surface Rendering (IR). DVR can be applied directly to a volume. It directly penetrates through the volume while it determines which voxels are visualizedbased on a transfer function. On the other hand, IR requires a series of processes such as segmentation, polygonization and visualization. To extract a region of interest (ROI) from the medical volume image via the segmentation, some regions of an object and a background are required, which are typically obtained from the user. To visualize the extracted regions, the boundary points of the regions should be polygonized. In other words, the boundary surface composed of polygons such as a triangle and a rectangle should be required to visualize the regions into 3D because illumination effects, which makes the object shaded and seen in 3D, cannot be applied directly to the points.

Effect of Hemiplegia Induced by Sciatic Nerve Injury on both Tibia Trabecular Bone of C57BL/6 Mouse (궁둥신경손상으로 인한 하지의 편마비가 양측 정강 뼈 해면골에 미치는 영향)

  • Jung, Young Jin;Seo, Dong Hyeon;Kim, Han Sung;Ko, Chang-Yong
    • Journal of Biomedical Engineering Research
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    • v.33 no.4
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    • pp.207-212
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    • 2012
  • It is widely known that sciatic nerve injury (SNI) can negatively affect the biomechanical characteristics of the musculoskeletal system. However, there were no studies that evaluated and compared denervated side with another side limb at the same time. In this study, sixteen male 12-week-old mice were allocated into two groups: HEMI (Right Sciatic nerve denervated) and CON (Control). Both limbs were scanned using micro-CT at 0 week and 4 weeks. There were significant differences in relative variation (RV) of BMD and all structural parameters compared CON and HEMI in right tibia (p < 0.05). Tb.Th and Tb.Sp distributions were differed CON with HEMI in right tibia. In left tibia, there were significant differences in RV of BMD (p < 0.05) and Tb.Sp distribution. These result means that SNI can induce bone loss in the both side tibiae. However, there was a different profile of bone loss between left and right tibiae.