• Title/Summary/Keyword: Resonance Type

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Clinical Study of the Treatment of Spondylolisthesis with Lumbar Herniated Intervertebral Disc (요추 추간판 탈출증을 동반한 척추전방전위증의 한방치료에 관한 임상적 고찰)

  • Kim, Tae-Ho;Yoon, Tae-Kyung;Yun, Young-Ung;Jeong, Seon-Yeong;Lee, Cha-Ro
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.9 no.1
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    • pp.15-26
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    • 2014
  • Objectives : The purpose of this study was to evaluate the effect of Korean medicicine treatment in patients with Spondylolisthesis and Lumbar Herniated Intervertebral Disc(HIVD). Methods : This clinical study was carried out on 62 patients who were diagnosed as spondylolisthesis and lumbar herniated intervertebral disc(HIVD) on L-spine X-ray and L-spine magnetic resonance imaging(MRI), who had been admitted from Feb. 2013 to Apr. 2014. All of 62 patients were treated with acupuncture, chuna treatment and herbal medicine during the whole admission period. Numerical rating scale(NRS) was used to evaluated the effectiveness of the oriental medical treatment. Results : 1. Distribution showed female predominance in general. 2. Degenerative type is the most common in this study. 3. In the duration of symptoms, the largest group was" Subacute"(32.26%). 4. Almost of patients had radiation pain, but in SLR test and valsalva test, more patients had no significant sign. 5. Spondylolytic type involved the 5th lumbar vertebra in 80% and degenerative type involved the 4th lumbar vertebra in 53.84%. 6. Most of case were grade 1(93.54%) in degree of slipping. 7. By the oriental medical treatment, NRS reduction in spondylolytic spondylolisthesis, was better than degenerative spondylolisthesis. Conclusions : The result of treatment by Korean medical is satisfactory for the tretment of spondylolisthesis.

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Structure-Reactivity Correlations in Nucleophilic Displacement Reactions of Y-Substituted-Phenyl X-Substituted-Cinnamates with Z-Substituted-Phenoxides

  • Son, Yu-Jin;Kim, Eun-Hee;Kang, Ji-Sun;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.34 no.8
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    • pp.2455-2460
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    • 2013
  • Second-order rate constants ($k_N$) have been measured spectrophotometrically for the nucleophilic displacement reactions of 4-nitrophenyl X-substituted-cinnamates (4a-4e) and Y-substituted-phenyl cinnamates (5a-5e) with Z-substituted-phenoxide anions in 80 mol % $H_2O$/20 mol % DMSO at $25.0{\pm}0.1^{\circ}C$. The Hammett plot for the reactions of 4a-4e with 4-chlorophenoxide (4-$ClPhO^-$) consists of two intersecting straight lines, which might be taken as a change in the rate-determining step (RDS). However, it has been concluded that the nonlinear Hammett plot is not due to a change in the RDS but is caused by stabilization of the ground state of substrates possessing an electron-withdrawing group in the cinnamoyl moiety through resonance interactions, since the Yukawa-Tsuno plot exhibits an excellent linear correlation with ${\rho}X=0.89$ and r = 0.58. The Br${\o}$nsted-type plot for the reactions of 4-nitrophenyl cinnamate (4c) with Z-substituted-phenoxides is linear with ${\beta}_{nuc}=0.76$. The Br${\o}$nsted-type plot for the reactions of Y-substituted-phenyl cinnamates (5a-5d) with 4-chlorophenoxides (4-$ClPhO^-$) is also linear with ${\beta}_{lg}=-0.72$. The Hammett plot correlated with ${\sigma}^-$ constants for the reactions of 5a-5d results in a much better linear correlation than that correlated with ${\sigma}^o$ constants, indicating that a partial negative charge develops on the O atom of the leaving aryloxide. Thus, the reactions have been concluded to proceed through a concerted mechanism.

Flow Analysis for Performance Characteristics with Closed Type Impeller Shapes of a Centrifugal Compressor (원심압축기 밀폐형 임펠러 형상에 따른 성능특성 파악을 위한 유동해석)

  • Cho, Jongjae;Yoon, YongSang;Cho, MyungHwan;Kang, SukChul
    • Journal of the Korean Society of Propulsion Engineers
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    • v.21 no.1
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    • pp.26-35
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    • 2017
  • The high-cycle fatigue cracking and the resonance generated in operation of a centrifugal compressor are main cause of the impeller damage. In order to prevent the damage, the impeller is designed or modified to have sufficient strength to withstand the operating condition. The damage prevent design will lead to a change of the flow condition and the performance characteristics of the compressor. In this study, the computational analysis were performed to identify the flow and the performance characteristics. The cases are a scalloped and a increased the blade thickness models with a closed type impeller. As the analysis results, the value of head coefficient and total to total efficiency for the increased the blade thickness model was decreased by each 0.5% and 0.1% than the values of the baseline model. Each value for the scalloped model was increased by 0.4% and was decreased by 1.6%.

Induced neural stem cells from human patient-derived fibroblasts attenuate neurodegeneration in Niemann-Pick type C mice

  • Hong, Saetbyul;Lee, Seung-Eun;Kang, Insung;Yang, Jehoon;Kim, Hunnyun;Kim, Jeyun;Kang, Kyung-Sun
    • Journal of Veterinary Science
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    • v.22 no.1
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    • pp.7.1-7.13
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    • 2021
  • Background: Niemann-Pick disease type C (NPC) is caused by the mutation of NPC genes, which leads to the abnormal accumulation of unesterified cholesterol and glycolipids in lysosomes. This autosomal recessive disease is characterized by liver dysfunction, hepatosplenomegaly, and progressive neurodegeneration. Recently, the application of induced neural stem cells (iNSCs), converted from fibroblasts using specific transcription factors, to repair degenerated lesions has been considered a novel therapy. Objectives: The therapeutic effects on NPC by human iNSCs generated by our research group have not yet been studied in vivo; in this study, we investigate those effects. Methods: We used an NPC mouse model to efficiently evaluate the therapeutic effect of iNSCs, because neurodegeneration progress is rapid in NPC. In addition, application of human iNSCs from NPC patient-derived fibroblasts in an NPC model in vivo can give insight into the clinical usefulness of iNSC treatment. The iNSCs, generated from NPC patientderived fibroblasts using the SOX2 and HMGA2 reprogramming factors, were transplanted by intracerebral injection into NPC mice. Results: Transplantation of iNSCs showed positive results in survival and body weight change in vivo. Additionally, iNSC-treated mice showed improved learning and memory in behavior test results. Furthermore, through magnetic resonance imaging and histopathological assessments, we observed delayed neurodegeneration in NPC mouse brains. Conclusions: iNSCs converted from patient-derived fibroblasts can become another choice of treatment for neurodegenerative diseases such as NPC.

Onlay patch augmentation in rotator cuff repair for moderate to large tears in elderly patients: clinical and radiologic outcomes

  • Sung-Yup Hong;Seung-Jin Lee;Hee-Bum Hahm;Ji-Woo Chang;Yoon-Suk Hyun
    • Clinics in Shoulder and Elbow
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    • v.26 no.1
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    • pp.71-81
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    • 2023
  • Background: This study evaluated the clinical and radiologic outcomes of onlay patch augmentation in rotator cuff repair for moderate-to-large tears in elderly patients. Methods: We reviewed 24 patients who underwent onlay augmentation with dermal allograft after arthroscopic rotator cuff repair from January 2017 to March 2020. Inclusion criteria were patients aged >65 years with tears >2.5 cm, who were followed for >12 months after surgery, and patients who could raise their arms above 90° preoperatively. American Shoulder and Elbow Surgeons (ASES) score, Constant-Murley score, pain visual analog scale (VAS), and VAS for satisfaction were used as clinical outcomes. For the evaluation of cuff integrity, magnetic resonance imaging scans were performed every 3 months after surgery. The results were compared before and after surgery in all patients and between the retear and intact groups. Results: The average follow-up period was 16.38 months, and the mean age of patients was 71.05 years. All patients showed significant improvement in ASES score, Constant-Murley score, and pain VAS at the last evaluation. The average value of satisfaction VAS was 7.27/10. The retear rate was 25% (6/24) if Sugaya type 3 was categorized in the retear group, otherwise 16.7% (4/24), if Sugaya type 3 was categorized into the intact group. Irrespective of Sugaya type 3 being included in the retear group, there was no significant difference in outcome variables between the intact and retear groups during follow-up. Conclusions: In moderate-to-large rotator cuff tear in elderly patients, onlay patch augmentation improved clinical outcomes. Retear did not adversely affect clinical outcomes.

Alpha-Glucosidase Inhibitory Activity of Saponins Isolated from Vernonia gratiosa Hance

  • Pham Van Cong;Hoang Le Tuan Anh;Le Ba Vinh;Yoo Kyong Han;Nguyen Quang Trung;Bui Quang Minh;Ngo Viet Duc;Tran Minh Ngoc;Nguyen Thi Thu Hien;Hoang Duc Manh;Le Thi Lien;Ki Yong Lee
    • Journal of Microbiology and Biotechnology
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    • v.33 no.6
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    • pp.797-805
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    • 2023
  • Species belonging to the Vernonia (Asteraceae), the largest genus in the tribe Vernonieae (consisting of about 1,000 species), are widely used in food and medicine. These plants are rich sources of bioactive sesquiterpene lactones and steroid saponins, likely including many as yet undiscovered chemical components. A phytochemical investigation resulted in the separation of three new stigmastane-type steroidal saponins (1 - 3), designated as vernogratiosides A-C, from whole plants of V. gratiosa. Their structures were elucidated based on infrared spectroscopy (IR), one-dimensional (1D) and two-dimensional nuclear magnetic resonance (2D NMR), high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and electronic circular dichroism analyses (ECD), as well as chemical reactivity. Molecular docking analysis of representative saponins with α-glucosidase inhibitory activity was performed. Additionally, the intended substances were tested for their ability to inhibit α-glucosidase activity in a laboratory setting. The results suggested that stigmastane-type steroidal saponins from V. gratiosa are promising candidate antidiabetic agents.

Review of Typical Fault Current Limiter Types and Application Effect to Improve Power System Reliability (전력 계통 신뢰도 개선을 위한 대표적인 한류기 유형 및 적용 효과 분석)

  • Yun-Seok Ko;Woo-Cheol Lee
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.6
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    • pp.1133-1142
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    • 2023
  • A rapid increase in power capacity in a power system can seriously reduce system reliability by causing the fault capacity to exceed the breaking capacity of circuit breaker. Fault current limiter is a practical and effective way to improve reliability by limiting fault capacity to the breaking capacity level. In this study, in order to help develop an application methodology when applying fault current limiters to power systems, first the topology and operating principles of each type of fault current limiters was reviewed, and the main advantages and disadvantages was compared. Next, to verify the effect of applying fault current limiter to the power system, the power system in which the fault current limiter was introduced was modeled. Finally, after simulating a three-phase short-circuit fault using EMTP-RV, the effect of application was verified by comparing the fault current before and after application of the fault current limiter and confirming that the fault current was reduced by the fault current limiter.

MR Imaging Findings of Uterine Cervical Adenocarcinoma (자궁경부 선암종의 자기공명영상 소견)

  • 김종철
    • Investigative Magnetic Resonance Imaging
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    • v.2 no.1
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    • pp.113-119
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    • 1998
  • Purpose : Because adenocarcinomas of the uterine cervix have lower 5-year survival rate than squamous cell carcinomas due to early lymph node metastasis and local extension, scrutiny of lymph node metastasis and local extension by radiologic examination is necessary in case of clinically diagnosed or suspected adenocarcinomas. The purpose of this study is to evaluate whether there are specific findings of these tumors, compared with squamous cell carcinomas, through the analysis of magnetic resonance (MR) imaging findings. Materials and Methods : Of 21 pathologically proven cervical adenocarcinomas, MR imaging findings of 18 tumors (histologic staging : two Ib, four IIa, two IIb, one IIIa, and one IIIb) were retrospectively analyzed and compared with those of 40 wquamous cell carcinoma in consecutive patients as a control group. T1-wetighted and fast spin echo T2-weighted images were obtained on the axial and sagittal planes, using a 1.5-T MR scanner. The largest diameter, location, signal intensity and degree of contrast enhancement contour, shape and longitudinal extent of the tumor and associated findings on MR image were analyzed. Results : The largest diameters of cervical adenocarcinomas ranged from 0.8 to 4.1 cm(mean, 2.2 cm). Of 18 adenocarcinomas, nine were of endocervical type. All adenocarcinomas were isointense to surrounding cervical stroma on T1-weighted images and hyperintense(homogeneous in ten, inhomogeneous in eight) on fast spin echo T2-weighted images. Adenocarcinomas enhanced on contrast study in all patients (homogeneous in six, inhomogeneous in 12 with hyperintese enhnacing rim in two). Eight adenocarcinomas had smooth contours and ten had irregular ones. The shape of adenocarcinoma was irregular in eight patients, barrel shape in six, papillary/polypod in three, and nodular in one. All adenocarcinomas involved lower half of the uterine cervix and six tumors extended up to the upper half. Pelvic lymph nodes of more than 1.5cm in diameter in two adenocarcinomas pateints and no detectable small pelvic lymph nodes on MR imaging in one patient were pathologically positive. Hydrometra was associated in two adenocarcinomas patients, and hematometra in one patient. Compared with squamous cell carcinomas, more frequent MR findings of endocervical type and barrel shape in cervical adenocarcinomas were statistically significant. Conclusion : Cervical adenocarcinomas had more frequent MR findings of endocervical type and barrel shape, compared with wquamous cell carcinomas. Adenocarcinoma of the uterine cervix may be suspected on MR imaging, when a cervical carcinoma is of barrel shape along the endocervical canal and tends to involve lymth nodes in earlier stages.

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Gas Transfer and Hemolysis Characteristics of a New Type Intravenous Lung Assist Device (혈관 내 신형 폐보조장치의 기체전달 및 용혈 특성)

  • 김기범;권대규;정경락;이삼철
    • Journal of Biomedical Engineering Research
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    • v.24 no.2
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    • pp.121-126
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    • 2003
  • The purpose of this work was to assess and quantify whether the beneficial effects in long-term gas exchange at exciting frequency were obtained at different frequencies as well and then to develop a vibrating intravascular lung assist device(VIVLAD), for Patients suffering from acute respiratory distress syndrome(ARDS) or chronic respiratory problems. We investigate the optimal condition of the frequency band excited with new vibrator at state of limit hemolysis when blood hemolysis came to through a membrane vibration action. The experimental design and procedures were given for a device used to assess the effectiveness of membrane vibrations. Quantitative experimental measurements were performed to evaluate the performance of the device . and to identify membrane vibration dependence on blood hemolysis. We developed an analytical solution for the hydrodynamics of flow through a bundle of sinusoidally vibrated hollow fibers that is used to provide some insight into how wall vibrations might enhance the performance of the VIVLAD. In the result, it was measured that the effect of various excited frequencies in gas transfer rate and hemolysis from the maximum gas transfer rate at no vibration when the maximum gas transfer rates showed at module type 6, module type 6 consisted of 675 hollow fiber membranes The maximum oxygen transfer rate was caused by the occurrence of maximum amplitude and transfer of vibration to hollow fiber membranes when it was excited by the frequency band of 7Hz at each blood flow rate. because this frequency became the End mode resonance frequency of the flexible in blood flow. Also, when module type 6 was excited at an excited frequency of 7Hz. blood hemolysis was low. Therefore, we decided that the limit of hemolysis frequency is 7Hz . because maximum amplitude occurred at this frequency.

Correlation Between Unidentified Bright Objects on Brain Magnetic Resonance Imaging (MRI) and Cerebral Glucose Metabolism in Patients with Neurofibromatosis Type 1

  • Sohn, Young Bae;An, Young Sil;Lee, Su Jin;Choi, Jin Wook;Jeong, Seon-Yong;Kim, Hyon-Ju;Ko, Jung Min
    • Journal of Genetic Medicine
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    • v.9 no.2
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    • pp.84-88
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    • 2012
  • Purpose: Neurofibromatosis type 1 (NF1), which is caused by mutations of the NF1 gene, is the most frequent single gene disorder to affect the nervous system. Unidentified bright objects (UBOs) are commonly observed on brain magnetic resonance imaging (MRI) in patients with NF1. However, their clinical and pathologic significance is not well understood. The purpose of this study was to investigate the correlation between UBOs and cerebral glucose metabolism measured by $^{18}F$-2-Fluoro-2-deoxy-D-glucose ($^{18}F$-FDG) positron emission tomography (PET) in Korean patients with NF1. Materials and Methods: Medical records of 75 patients (34 males and 41 females) with NF1 who underwent brain MRI and PET between 2005 and 2011 were evaluated retrospectively. Clinical data including demographics, neurological symptoms, and brain MRI and PET findings, were reviewed. Results: UBOs were detected in the brain MRI scans of 31 patients (41%). The region most frequently affected by UBOs was the basal ganglia. The most frequent brain PET finding was thalamic glucose hypometabolism (45/75, 60%). Of the 31 patients with UBOs, 26 had thalamic glucose hypometabolism on brain PET, but the other 5 had normal brain PET findings. Conversely, of the 45 patients with thalamic glucose hypometabolism on brain PET, 26 showed UBOs on their brain MRI scans, but 19 had normal findings on brain MRI scans. Conclusion: UBOs on brain MRI scans and thalamic glucose hypometabolism on PET appear to be 2 distinctive features of NF1 rather than correlated symptoms. Because the clinical significance of these abnormal imaging findings remains unclear, a longitudinal follow-up study of changes in clinical manifestations and imaging findings is necessary.