• Title/Summary/Keyword: Spin

Search Result 3,823, Processing Time 0.031 seconds

The Effect of Nuclear Overhauser Enhancement in Liver and Heart $^{31}P$ NMR Spectra Localized by 2D Chemical Shift Technique (이차원 화학변위 기법을 이용한 간 및 심장 $^{31}P$ 자기공명분광에서의 Nuclear Overhauser 효과에 대한 연구)

  • Ryeom Hun-Kyu;Lee Jongmin;Kim Yong-Sun;Lee Sang-Kwon;Suh Kyung-Jin;Bae Sung-Jin;Chang Yongmin
    • Investigative Magnetic Resonance Imaging
    • /
    • v.8 no.2
    • /
    • pp.94-99
    • /
    • 2004
  • Purpose : To investigate the signal enhancement ratio by NOE effect on in vivo $^{31}P$ MRS in human heart muscle and liver. we also evaluated the enhancement ratios of different phosphorus metabolites, which are important in 31P MRS for each organ. Materials and Methods : Ten normal subjects (M:F = 8:2, age range = 24-32 yrs) were included for in vivo $^{31}P$ MRS measurements on a 1.5 T whole-body MRI/MRS system using $^1H-^{31}P$ dual tuned surface coil. Two-dimensional Chemical Shift Imaging (2D CSI) pulse sequence for $^{31}P$ MRS was employed in all $^{31}P$ MRS measurements. First, $^{31}P$ MRS performed without NOE effect and then the same 2D CSI data acquisitions were repeated with NOE effect. After postprocessing the MRS raw data in the time domain, the signal enhancements in percent were estimated from the major metabolites. Results : The calculated NOE enhancement for liver $^{31}P$ MRS were $\alpha-ATP\;(7\%),\;\beta-ATP\;(9\%),\;\gamma-ATP\;(17\%),\;Pi\;(1\%),\;PDE\;(19\%)$ and $PME\;(31\%)$. Because there is no creatine kinase activity in liver, PCr signal is absent. For cardiac $^{31}P$ MRS, whole body coil gave better scout images and thus better localization than surface coil. In $^{31}P$cardiac multi-voxel spectra, DPG signal increased from left to right according to the amount of blood included. The calculated enhancement for cardiac $^{31}P$ MRS were : $\alpha-ATP\;(12\%),\;\beta-ATP\;(19\%),\;\gamma-ATP\;(30\%),\;PCr\;(34\%),\;Pi\;(20\%),\;(PDE)\;(51\%),\;and\;DPG\;(72\%)$. Conclusion : Our results revealed that the NOE effect was more pronounced in heart muscle than in liver with different coupling to 1H spin system and thus different heteronuclear cross-relaxation.

  • PDF

Study of Animation Comicality, Characters in (<슈렉> 캐릭터에 나타난 애니메이션 희극성 연구)

  • Lee, Chae-Ron
    • Cartoon and Animation Studies
    • /
    • s.38
    • /
    • pp.145-176
    • /
    • 2015
  • In animation, 'laughter' is an important factor for the fun. Dreamworks' animation is a successful popular animation. It has four series and spin-off animations, and settled as a successful case that created fun with strategic use of parody throughout the productions. Most preceding studies on this animation have focused on its humor, parody, and satire. However, not many studies have discussed its independent comedy as a piece of animation that satisfies the needs of public. This study considered that viewers' desire to watch an animation comes from their fantasies to discuss the comedy of based on its animated characters. Animated characters communicate with the public with wits that ignore the rules of reality. The characters that do not exist in reality are created and animated to turn the world of reality upside down. The comedy in comes from the entertaining deformation of the society's fixed ideas and prejudices. It is a fun variation of the ideology behind fairy tales created by the Disney animations to challenge Disney in the animation market in reality, and twisted the world of fairy tales in the story to quench the thirst of the public. 'Shrek', a monstrous character, stands in the center of the story. A monstrous character that always played an anti-role has become the main character to break the rule of fairy tales. This is the subjectivation of anti-character. Second, it is a new anti-character with an exaggerated and distorted body. Lord Farquad, who looks abject compared to the monstrous character for a person with so much power and ambition, brings laughter. Third, it is the variation of various characters from fairy tales. The conventional fairy tale characters, both animals and non-living things, come out of the box and appear as humorous characters that bring life to the story. uses comedy characters in the process of reinterpreting the fixed ideas, prejudices, and ideologies of the real world created by fairy tales. I hope that it helps Korean animations establish a successful format for creating characters that bring life to the stories.

Selection of TI for Suppression Fat Tissue of SPAIR and Comparative Study of SPAIR and STIR of Brain Fast SE T2 Weighted Imaging (뇌의 고속스핀에코 T2강조영상에서 지방조직 억제를 위한 SPAIR의 반전시간(TI) 결정 및 STIR 영상과의 비교 연구)

  • Lee, Hoo-Min;Kim, Ham-Gyum;Kong, Seok-Kyo
    • Journal of radiological science and technology
    • /
    • v.32 no.1
    • /
    • pp.95-99
    • /
    • 2009
  • The purpose of this research is to seek SPAIR's reversal time (TI) which satisfies two conditions ; maintaining the suppression ability of fat tissue and simultaneously minimizing the inhomogeneity of fat tissue in T2 high-speed spin echo 3.0T magnetic resonance image (MRI) of the brain, and to compare SPAIR with STIR which is fat-suppression technique. The reversal times (TI) of SPAIR protocol are set to 1/2, 1/3, 1/6 and 1/12 of SPAIR TR (420 msec), namely 210 msec (8 people), 140 msec (26 people), 70 msec (26 people) and 35 msec (18 people) and STIR TI is set with 250 msec (26 people). With these parameter sets, we acquired the axis direction 104 images of the brain. In ROI ($50\;mm^2$) of output image, signal intensities of the fatty tissue, the muscular tissue, and the background were measured and the CNRs of fatty tissue and the muscular tissue were calculated. The inhomogeneity of the fatty tissue is SD/mean, where SD is the standard deviation and 'mean' is a average fatty tissue signal. Consequently, SPAIR TI is determined on either 1/3 or 1/6 of TR (420 ms) ; 140 ms or 70 ms. Because the difference of statistics in fat-suppression ability and inhomogeneity of fatty tissue is very small (p < 0.001), Selecting 140 ms seems to be better choice for the image quality. Meanwhile, Comparing SPAIR (TI : 140 ms) with STIR, the fat-suppression is not able to be considered statistically (p < 0.252), but the image quality is able to be considered statistically (p < 0.01). In conclusion, SPAIR is better than STIR in the image quality.

  • PDF

Comparison of Anti-Oxidative Activities of Gamma-Irradiated Aralia continentalis Extracts for Long-Term Storage of Oriental Medicine (한약재 장기 보존을 위해 감마선 조사한 독활(Aralia continentalis) 추출물의 항산화 효과 비교)

  • Park, Hye-Jin;Hong, Eun-Jin;Hong, Shin-Hyub;Cho, Young-Je
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.46 no.1
    • /
    • pp.46-55
    • /
    • 2017
  • In this study, extracts of gamma-irradiated Aralia continentalis for health and beauty food resources were examined on antioxidant activities and increasing extraction yield. In photostimulated luminescence analysis, non-irradiated (0 kGy) sample showed an intermediate result of 891.00 photon counts (PCs), whereas irradiated (5 and 10 kGy) samples showed positive results of 79,956.67 and 282,498.67 PCs, respectively. The thermoluminescence ratio of non-irradiated samples was 0.018, whereas the values of irradiated samples (5 and 10 kGy) were 0.395 and 0.464, respectively. Electron spin resonance (ESR) analysis as a physical technique for irradiation identification of Aralia continentalis showed a pair of peaks on a space of 6.0 mT in the symmetric ESR spectrums. For phenolics of gamma-irradiated Aralia continentalis, water extracts had the highest amounts of 7.61 mg/g at non-irradiated condition (0 kGy) while 50% ethanol extracts had the highest amounts of 6.86 mg/g at 10 kGy irradiation. 2,2-Diphenyl-1-picrylhydrazyl scavenging activity of water and 50% ethanol extracts from non-irradiated and irradiated Aralia continentalis were very high (94.99~100.00%). 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation inhibitory activity was over 95.00% at $200{\mu}g/mL$ phenolics. Antioxidant protection factor (PF) showed a very high level of activity (1.38~2.51 PF). Thiobarbituric acid reactive substance inhibitory activity was high (70% and 95%, respectively). Thus, treatment of gamma irradiation can be used as a method of storage for long-term preservation of Oriental medicine.

Diffusion-Weighted MR Imaging of the Brain Tumors: The Clinical Usefulness (두개강내 종양의 확산강조자기공명영상: 임상적 유용성)

  • 이영철;서정진;정광우;강형근;김윤현
    • Investigative Magnetic Resonance Imaging
    • /
    • v.4 no.1
    • /
    • pp.34-41
    • /
    • 2000
  • Purpose: To evaluate the clinical usefulness of diffusion weighted MR imaging(DWI) in the differential diagnosis of brain tumors. Materials and methods: DWI and conventional MR images of nineteen patients with brain tumors(10 metastatic tumors, 4 high grade gliomas, 4 low grade astrocytomas, one oligodendroglioma)were obtained on 1.5T unit. DWI was obtained using single shot spin echo planar imaging with b-value near 1000. We analyzed the signal intensities of lesions including solid portion, necrotic or cystic portion and peritumoral edema of brain tumors (classified five grades comparison with the signal intensities of brain parenchyma and CSF)and calculate the SIR(signal intensity ratio)of lesions to the contralateral normal brain parenchyma. We analyzed statistically the signal intensities and SIR of tumors using independence T test. Results: In solid portions of tumors, all the metastatic tumors and high grade gliomas showed high signal intensities, but low grade astrocytomas and oligodendroglioma showed iso or slight high signal intensities to the normal brain parenchyma. The SIR of solid portion has positive correlation with malignant pot ential(metastatic tumors 1.52, high grade gliomas 1.38, low grade astrocytomas 1.16, oligodendroglioma 1.31)(p < 0.05). In peritumoral edema where seen in 14 tumors, seven of 10 metastatic tumors and two of 4 high grade gliomas showed iso signal intensities, whereas edemas in other 5 brain tumors showed hyperintense to the normal brain parenchyma. The SIRs of peritumoral edemas in metastatic tumors (1.14) was lower than high grade gliomas(1.31),but statistically insignificant. The SIR of cystic or necrotic portion of brain tumors was 0.63. In non enhancing solid portions, three of six cases showed hyperintense to the adjacent peritumoral edema. Conclusion: On DWI, the signal intensities of solid portion has positive correlation with malignant potential, and perilesional edema of brain tumors appear various signal intensities owing to "T2 shine through effect" and the extensiveness of vasogenic edema. Another merit using DWI on the evaluation of brain tumors is to improved better delineation of tumor margins from the adjacent edemas, especially at the non enhancing solid portion of the tumors.

  • PDF

The Development of Theoretical Model for Relaxation Mechanism of Sup erparamagnetic Nano Particles (초상자성 나노 입자의 자기이완 특성에 관한 이론적 연구)

  • 장용민;황문정
    • Investigative Magnetic Resonance Imaging
    • /
    • v.7 no.1
    • /
    • pp.39-46
    • /
    • 2003
  • Purpose : To develop a theoretical model for magnetic relaxation behavior of the superparamagnetic nano-particle agent, which demonstrates multi-functionality such as liver- and lymp node-specificity. Based on the developed model, the computer simulation was performed to clarify the relationship between relaxation time and the applied magnetic field strength. Materials and Methods : The ultrasmall superparamagnetic iron oxide (USPIO) was encapsulated with biocompatiable polymer, to develop a relaxation model based on outsphere mechanism, which was resulting from diffusion and/or electron spin fluctuation. In addition, Brillouin function was introduced to describe the full magnetization by considering the fact that the low-field approximation, which was adapted in paramagnetic case, is no longer valid. The developed model describes therefore the T1 and T2 relaxation behavior of superparamagnetic iron oxide both in low-field and in high-field. Based on our model, the computer simulation was performed to test the relaxation behavior of superparamagnetic contrast agent over various magnetic fields using MathCad (MathCad, U.S.A.), a symbolic computation software. Results : For T1 and T2 magnetic relaxation characteristics of ultrasmall superparamagnetic iron oxide, the theoretical model showed that at low field (<1.0 Mhz), $\tau_{S1}(\tau_{S2}$, in case of T2), which is a correlation time in spectral density function, plays a major role. This suggests that realignment of nano-magnetic particles is most important at low magnetic field. On the other hand, at high field, $\tau$, which is another correlation time in spectral density function, plays a major role. Since $\tau$ is closely related to particle size, this suggests that the difference in R1 and R2 over particle sizes, at high field, is resulting not from the realignment of particles but from the particle size itself. Within normal body temperature region, the temperature dependence of T1 and T2 relaxation time showed that there is no change in T1 and T2 relaxation times at high field. Especially, T1 showed less temperature dependence compared to T2. Conclusion : We developed a theoretical model of r magnetic relaxation behavior of ultrasmall superparamagnetic iron oxide (USPIO), which was reported to show clinical multi-functionality by utilizing physical properties of nano-magnetic particle. In addition, based on the developed model, the computer simulation was performed to investigate the relationship between relaxation time of USPIO and the applied magnetic field strength.

  • PDF

Normal MR Spectroscopic Findings of the Cerebellum and Pons: Comparison of the Results between Intra-Unit and Inter-Unit Studies (소뇌와 뇌교의 정상 자기공명분광 소견: 같은 장비내 및 다른 장비간의 결과 비교)

  • 최준일;장기현;송인찬;도강현;이준우
    • Investigative Magnetic Resonance Imaging
    • /
    • v.5 no.2
    • /
    • pp.123-129
    • /
    • 2001
  • Purpose: The purposes of this study are to evaluate normal MR spectroscopy (MRS) data of the cerebellum and pons, and to evaluate intra-unit and inter-unit differences of the results. Materials and methods: Nine normal volunteers (mean age 23 years) were studied with two 1.5 Tesla MR units (A and B units). A total of four sessions of MRS study were performed with two sessions in ea.ch MR unit in each volunteer. In each session, MRS data were obtained from bilateral cerebellar hemisphere and pons. MRS was performed using spin-echo single voxel technique with repetition time of 2000 ms, echo time of 288ms and 128 averagings. Voxel size was $2{\;}{\times}{\;}2{\;}{\times}{\;}1.5{\;}cm$ in the cerebellum and $1.5{\;}{\times}{\;}1.5{\;}{\times}{\;}1.5{\;}cm$ in the pons. Metabolite ratios of NAA/Cho, NAAcCr, NAAc(Cho+Cr) and Cr/Cho (both peak heights and the peak areas) were compared among the results of four sessions of MRS for evaluation of intra-unit and inter-unit differences. Results: In the cerebellum, mean (SO values of peak height NAA/Cho, NAA/Cr, NAA/(Cho+Cr) and Cr/Cho ratios obtained in the first session of A unit were $1.08{\pm}O.16,{\;}1.44{\pm}O.286,{\;}0.61{\pm}O.09{\;}and{\;}O.76{\pm}0.13$, respectively. Comparing with the results of the second session, intra-unit differences were 3-7%. In B unit intra-unit differences were 1-9%, except for 22% of Cr/Cho ratio. Inter-unit differences between A and B units were 1-26%. In the pons, mean ISD values of peak height NANCho, NANCr, NANICho + Cr) and Cr/Cho ratios obtained in the first session of A unit were $1.51{\pm}O.35,{\;}3.35{\pm}O.78,{\;}1.02{\pm}0.16{\;}and{\;}0.47{\pm}O.14$, respectively. Mean NAAfCho, NANCr and NAAI(Cho+ Cr} ratios of the pons were significantly higher than those of the cerebellum. Intra-unit differences were 2-21 % in A unit and 4-18 % in B unit. Inter-unit differences between A and B units were 1-18%. The mean values obtained by using peak area were generally higher and wider in range than those of peak height in both units. Conclusion: Mean NAAfCho, NAAlCr and NAAf(Cho+Cr) ratios of the cerebellum were significanHy lower than those of the pons. Intra-unit differences of most metabolites ratios were generally not significant, whereas inter-unit differences were greater than intra-unit differences in more metabolite ratios. Therefore, normal MRS data of the cerebellum and the pons should be obtained in every MR unit, before MRS applications in the diseases of the cerebellum and the pons.

  • PDF

In Vitro Imaging of MRI and Ultrasound for Gastric Carcinoma (위암 조직의 자기공명영상과 초음파 소견에 대한 비교 연구)

  • Kil, Sung-Won;Jee, Keum-Nahn
    • Investigative Magnetic Resonance Imaging
    • /
    • v.12 no.2
    • /
    • pp.178-187
    • /
    • 2008
  • Purpose : To evaluate and compare the diagnostic accuracy of MRI and ultrasound(US) for estimation of invasion depth of gastric carcinoma by correlation with histopathologic findings in vitro and to find out the best MR pulse sequence for detection and accurate delineation of tumor. Materials and Methods : Resected specimen of total or subtotal gastrectomy from 53 patients with gastric carcinoma were done of imaging studies of MRI and US. And US was examined by using high frequency linear transducer for tumor invasion depth by a radiologist. In each case, both imaging findings of MRI and US were evaluated independently for tumor detection and invasion depth by consensus of two radiologists and were compared the diagnostic accuracy between two imaging modalities according to the histopathologic findings. MR imaging with five MR pulse sequences, spin echo T1 and in- and out-of phase gradient echo T1 weighted images, FSE and SSFSE T2 weighted images, were performed. Five MR pulse sequences were evaluated and compared on the point of detection and accurate distinction of tumor from surrounding normal tissue. Results : In EGC, diagnostic accuracy of US(77%) was superior than that of MRI(59%) but no statistically significant difference was noted between two imaging modalities(p=0.096). In AGC, both imaging modalities of MRI and US showed relatively high diagnostic accuracy as 97% and 84% respectively. Diagnostic accuracy of MRI was statistically better than that of US at the significant level(p<0.001). The best MR pulse sequence among five in each specimen was FSE T2WI(75.5%, 40/53) in both EGC and AGC. In AGC, FSE T2WI showed excellent imaging quality by showing very high ratio (93.5%, 29/31) of accurate delineation of tumor. Conclusion : MRI and US show relatively high diagnostic accuracy in the evaluation of tumor invasion depth of resected specimen in AGC. The most excellent pulse sequence of MRI for the evaluation of tumor invasion depth is FSE T2WI on the point of detection and accurate delineation of tumor in both EGC and AGC.

  • PDF

Optical properties of $ZnIn_2Se$ and $ZnIn_2Se_4$:Co single crystals ($ZnIn_2Se_4$$ZnIn_2Se_4$:Co 단결정의 광학적 특성)

  • 최성휴;방태환;박복남
    • Journal of the Korean Vacuum Society
    • /
    • v.6 no.2
    • /
    • pp.129-135
    • /
    • 1997
  • Undoped and Co-doped $ZnIn_2Se_4$ single crystals crystallized in the tetragonal space group 142m, with lattice constants a=5.748 $\AA$ and c=11.475 $\AA$, and a=5.567 $\AA$ and c=11.401 $\AA$. The optical absorption measured near the fundamental band edge showed that the optical energy band structure of these compounds had an indirect band gap, the direct and the indirect energy gaps of these compounds decreased as temperature changed from 10 to 300 K. The temperature coefficients of the direct energy gaps were found to be $\alpha=3.71\times10^{-4}$eV/K and $\beta$=519 K for $\alpha=3.71\times10^{-4}$eV/K and $\beta$=421K for $ZnIn_2Se_4$: Co. The temperature coefficients of the indirect energy gaps were also found to be $\alpha=2.31\times10^{-4}$ eV/K and $\beta$=285 K for $ZnIn_2Se_4$, and $\alpha=3.71\times10^{-4}$eV/K and $\beta$=609 K for $ZnIn_2Se_4$:Co, respectively. Six impurity optical absorption peaks due to cobalt are observed in $ZnIn_2Se_4$:Co single crystal. These impurity optical absorption peaks can be attibuted to the electronic transitions between the split energy levels of$CO^{2+}$ ions located at Td symmetry site of $ZnIn_2Se_4$ host lattice. The 1st order spin-orbit coupling constant ($\lambda$), Racah parameter (B), and crystal field parameter (Dq) ARE GIVEN AS -$243\textrm{cm}^{-1}, 587\textrm{cm}^{-1}, \;and\;327\textrm{cm}^{-1}$, respectively.

  • PDF

Analysis of Success Factors for Effective Stroke of Golf Beginners (골프 입문자들의 유효타에 대한 성공요인 분석)

  • Woo, Byung-Hoon
    • Journal of the Korean Applied Science and Technology
    • /
    • v.37 no.5
    • /
    • pp.1190-1199
    • /
    • 2020
  • The purpose of this study is to analyze the variables affecting the effective stroke in the swing performed through 12 weeks of training for golf beginners, and to provide basic data on the effective stroke factors for the golf beginners to settle on the fairway. Twenty subjects were participate in the study (age: 21.35±1.69 yrs, height: 176.75±7.99 cm, weight: 70.70±9.76 kg). All subjects were subjected to a 12-week golf training, and trackman 4 was used in the 12th week to calculate variables affecting the effective stroke during a golf swing. Trackman data was divided into club-variables and ball-variables, and a binary logistic regression analysis was performed to find out the variables affecting effective strokes. In club-variables, high dynamic loft and low face angles were found in effective stroke, and in ball-variables, fast ball speed, large smash factor, high launch angle, and many spin rates were also found in effective stroke. As a result of the binary logistic regression analysis of club-variables, the probability of an effective stroke increased as the club speed and dynamic loft increased, and the probability of an effective stroke decreased as the face angle increased. The influence of effective stroke in the club-variables was in the order of dynamic loft, face angle, and club speed. In the ball-variable, the probability of an effective stroke increased when the lunch angle increased, and the probability of an effective stroke decreased as the lunch direction increased. As a condition to increase the probability of effective stroke based on the results, it is necessary to increase the club speed through high dynamic loft and low face angle during swing through continuous practice. Through this, the probability of effective stroke through increasing the launch angle and decreasing the launch direction will increase.