• Title/Summary/Keyword: SV30

Search Result 189, Processing Time 0.027 seconds

Myocardial Blood Flow Quantified by Low-Dose Dynamic CT Myocardial Perfusion Imaging Is Associated with Peak Troponin Level and Impaired Left Ventricle Function in Patients with ST-Elevated Myocardial Infarction

  • Jingwei Pan;Mingyuan Yuan;Mengmeng Yu;Yajie Gao;Chengxing Shen;Yining Wang;Bin Lu;Jiayin Zhang
    • Korean Journal of Radiology
    • /
    • v.20 no.5
    • /
    • pp.709-718
    • /
    • 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.

Determine the hazards of radioactive elements and radon gas manufacturing processes in an Egyptian fertilizer factory

  • Soad Saad Fares
    • Nuclear Engineering and Technology
    • /
    • v.56 no.5
    • /
    • pp.1781-1795
    • /
    • 2024
  • This study investigated the levels of radioactivity in soil surrounding a phosphate fertilizer factory in Egypt, aiming to assess potential risks to the population exposed to radiation. Concentrations of 238U, 226Ra, 232Th, and 40K were measured in soil samples collected from two subsites: one near the factory (subsite 1) and another further away (subsite 2). Two different systems were used for measuring radioactivity, a high-purity gamma ray spectroscopy system with an HPGe detector for gamma-emitting isotopes and a CR-39 solid nuclear track detector for alpha-emitting radon gas. Subsite 1, located close to the factory, displayed significantly elevated levels of 226Ra compared to global background levels (514 and 456 Bq/kg vs. 35 Bq/kg). Additionally, the concentrations of 238U (241.06 Bq/kg vs. global average 35 Bq/kg), 232Th (16.15 Bq/kg vs. global average 30 Bq/kg), and 40K (146.36 Bq/kg vs. global average 400 Bq/kg) were all above global averages. Furthermore, a high concentration of radon gas (337.06 μSv/y) was measured at subsite 1. The strong positive correlation observed between 226Ra and 238U (0.96256) provides further evidence of potentially elevated radioactivity levels near the factory. In contrast, subsite 2, situated farther from the factory, exhibited natural radioactive background levels within international limits. Quantitative analysis revealed that gamma ray absorbed doses for 226Ra and 232Th exceeded global averages in some samples. Specifically, 226Ra doses ranged from 7.8 to 46.26 ppm (exceeding the 20 ppm global average in some cases), and 232Th doses ranged from 1.98 to 9.14 ppm (exceeding the 10 ppm global average in some cases). The concentration of 40K, however, remained within the global range (0.07%-0.69 %). The observed imbalances in the ratios of Th/U (0.17-0.24 Bq/kg and 0.73-0.24 ppm) and U/Ra (0.81-0.73 Bq/kg and 0.73-0.17 ppm), both of which are significantly lower than their respective global averages of 4 and 2.4, point towards the presence of fertilizer-derived contamination. This conclusion is further supported by the high phosphate concentrations detected in the samples. Overall, this study suggests that radioactive contamination near the phosphate fertilizer factory significantly exceeds global background levels and international limits in some cases. This raises concerns about potential risks posed to surrounding agricultural land and crops.

Comparative Analysis of Absorption Doses between Exposed and Unexposed Area on Major Organs During CT Scan (전산화 단층촬영시 주선속내 외의 주요장기 흡수선량 비교분석)

  • 사정호;서태석;최보영;정규회
    • Progress in Medical Physics
    • /
    • v.11 no.1
    • /
    • pp.59-71
    • /
    • 2000
  • It is possible to obtain a fast CT scan during breath holding with spiral technique. But the risk of radiation is increased due to detailed and repeated scans. However, the limitation of X-ray doses is not fully specified on CT, yet. Therefore, the purpose of the present study is to define the limitation of X-ray doses on CT The CT unit was somatom plus 4. Alderson Rando phantom, Solenoid water phantom, TLD, and reader were used. For determining adequate position and size of organs, the measurement of distance(${\pm}$2mm) from the midline of vertebral body was performed in 40 women(20~40 years). On the brain scan for 8:8(8mm slice thickness, 8mm/sec movement velocity of the table) and 10:10(10mm slice thickness, 10mm/sec movement velocity of the table) methods, the absorption doses of exposed area of the 10:10 were slightly higher than those of 8:8. The doses of unexposed uterus were negligible on the brain scan for both 8:8 and 10:10. On the chest scan for 8:8, 8:10(8mm slice thickness, 10mm/sec movement velocity of the table), 10:10, 10:12(10mm slice thickness, 12mm/sec movement velocity of the table) and 10:15(10mm slice thickness, 15mm/sec movement velocity of the table) methods, 8:8 method of the absorption doses of exposure area was the most highest and 10:15 method was the most lowest. The absorption doses of 8:10 method was relatively lower than those of the other methods. In conclusion, the 8:10 method is the most suitable to give a low radiation burden to patient without distorting image quality.

  • PDF

Effect of fabrication method and surface polishing on the surface roughness and microbial adhesion of provisional restoration (임시 수복물의 제작 방식과 표면 연마가 표면 거칠기와 세균 부착에 미치는 영향)

  • Yeon-Ho Jung;Hyun-Jun Kong;Yu-Lee Kim
    • Journal of Dental Rehabilitation and Applied Science
    • /
    • v.40 no.3
    • /
    • pp.149-158
    • /
    • 2024
  • Purpose: This study aims to investigate the effects of provisional restoration fabrication methods and surface polishing on surface roughness and microbial adhesion through in vitro experiments. Materials and Methods: 120 cylindrical provisional restoration resin blocks (10 × 10 × 2.5 mm) were manufactured according to four fabrication methods, and 30 specimens were assigned to each group. Afterwards, they were divided into non-polishing group, #400 grit SiC polishing group, and #800 grit SiC polishing group and polished to a 10 × 10 × 2 mm specimen size (n = 10). The surface roughness Ra and Ry of the specimen was measured using a Surface Roughness Tester. Three specimens were extracted from each group and were coated with artificial saliva, and then Streptococcus mutans were cultured on the specimens at 37℃ for 4 hours. The cultured specimens were fixed to fixatives and photographed using a scanning electron microscope. For statistical analysis, the two way of ANOVA was performed for surface roughness Ra and Ry, respectively, and the surface roughness was tested post-mortem with a Scheffe test. Results: The fabrication method and the degree of surface polishing of the provisional restorations had a significant effect on both surface roughness Ra and Ry, and had an interaction effect. There was no significant difference in Ra and Ry values in all polishing groups in DLP and LCD groups. Conclusion: The fabrication method and surface polishing of the provisional restoration had a significant effect on surface roughness and showed different adhesion patterns for S. mutans adhesion.

Effect of different pattern size and pattern shape on castability of commercially pure titanium (납형의 크기와 형태가 티타늄의 주조성에 미치는 영향)

  • Seo, Yoon-Jeong;Oh, Gye-Jeong;Lee, Hyo-Il;Shin, Yoo-Jin;Kim, Hong-Joo;Park, Sang-Won
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.51 no.4
    • /
    • pp.261-268
    • /
    • 2013
  • Purpose: The purpose of this study was to investigate the effect of geometrically different wax pattern shapes and sizes on the castability of Grade2 Cp-Ti (commercially pure titanium). Materials and methods: Total of 40 mesh wax pattern ($61mm{\times}24mm$, 207 grids), ($61mm{\times}17mm$, 138 grids) was cast in this experiment. Depending on the geometrical shape of the wax pattern, 8 groups was organized; Flat, Semicircular, Horse-shoe and V-shape, each consisting 5 samples. Runner-bar sprue was used in all patterns. The number of completely cast grid in wax pattern served as a measure for the castability of comercially pure titanium. Results: The mean value of square count in each group was as followed; 133.20 squares in group SS (96.52%), 132.40 squares in group SH (95.94%), 132.00 squares in group SF (95.65%), 127.60 squares in SV (91.43%), 198.60 squares in group LF (95.94%), 197.80 squares in group LV (95.56%), 196.40 squares in group LS (94.88%), and 188.00 squares in group LH (90.82%). Conclusion: Within the limitations of this study the results indicate that there were no sttistically significant difference in castability of titanium regarding wax pattern shape (P>.05). However, Small size wax patterns were showing the noticeable castability more than Large size pattern.

Correlation of Effective Dose and BMI in Radioiodine($^{131}I$) Therapy (방사성옥소($^{131}I$) 치료 시 유효선량과 체질량지수의 상관관계)

  • Shin, Gyoo-Seul;Kim, Gun-Jae;Dong, Kyung-Rae;Kim, Hyun-Soo
    • Journal of radiological science and technology
    • /
    • v.31 no.1
    • /
    • pp.11-16
    • /
    • 2008
  • Purpose : The aim of this study was to predict radiation dose at 1 meter with BMI(body mass index) in thyroid cancer patients treated with radio-iodine and provide the efficient guideline in the management of patients. Methods : 140 patients from thyroidectomy for thyroid cancer were enrolled. All subjects under went 150 mCi radio-iodine therapy and performed whole body scan 1 week later. BMI(weight divided by square of height) was calculated to evaluate the amount of fatty tissue indirectly. The radiation dose at 1 meter was measured initially and on 2nd days. the relation of values with BMI were analyzed statically. As for the method of statistical analysis, using Med calc Version 9,2,2,0 Program. Results : (1) The initial effective dose was inversely correlated with the BMI. Significance level was 0.0004. (2) We obtained the following formula from the data of initial effective dose and BMI: Y = -30.91X + 350.4(${\mu}Sv/h$)(Y: initial radiation dose, x: Group). (3) After 21.55 hours, than radiation dose was less than those recommended by ICRP or NRC in 53% of the population. Conclusion : Using BMI, the initial radiation dose and 2nd days dose can be predicted in thyroid cancer patients before radio-iodine therapy. It may be used for predicting the time of discharge and control the isolation room. We were able to predict the radiation exposure after discharge using this calculated value.

  • PDF

PROPERTIES OF FLUORIDE-RELEASING RESIN COMPOSITE RESTORATIVE MATERIALS (불소방출성 콤포짓트 레진계 수복재의 특성)

  • Kim, Sang-Hoon;Baik, Byeong-Ju;Kim, Jae-Gon;Yang, Yeon-Mi;Park, Jeong-Yeol
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.35 no.3
    • /
    • pp.418-426
    • /
    • 2008
  • The objectives of this study were to examine the properties of fluoride-releasing resin composite restorative materials. Four commercially available compomer materials (Compoglass F: CF, $Dyract^{(R)}$ AP: DA, $Dyract^{(R)}$ flow: DF, F2000: FT) and one fluoride-releasing composite resin ($Tetric^{(R)}$ Ceram: TC) were selected as experimental materials. Rectangular-shaped tensile test specimens were fabricated in a teflon mold giving 5mm in gauge length and 2mm in thickness. Disk-shaped specimens were fabricated in the split teflon mold with diameter of 15mm and thickness of 1mm. After curing for an hour, specimens were immersed in deionized water at $37^{\circ}C{\pm}1^{\circ}C$ for 30 days. All specimens were thermocycled for 10,000 cycles with 15 seconds of dwelling time in each $5^{\circ}C$ and $55^{\circ}C$ water baths. Toothbrush abrasion test was conducted under a load of 1.5 N and the abraded surfaces were examined with surface roughness tester (SV-3000, Mitutoyo Co, Japan) and SEM (JSM-5800, JEOL, Japan). Fluoride recharging was done by toothbrushing for 3 min. using a fluoride toothpaste (Perio Alpine Herb, LG Household & Health Care, Korea). The results obtained were summarized as follows; 1. The highest tensile strength value of 32.3 MPa was observed in TC group and the lowest value of 16.8 MPa was observed in CF group. The tensile strength of TC group was significantly higher than those of CF and DF groups (P<0.05). 2. The lowest Ra value of 0.287 was observed in TC group and the highest value of 1.516 was observed in FT group. The Ra value of FT group was significantly higher than other groups (P<0.05). 3. The abraded surfaces revealed the increase of surface roughness due to the protrusion and missing of filler particles. 4. The release of fluoride of compomers after tooth brushing by Perio Alpine Herb was initially large and then followed by small and continuously. But it remains small and constant in fluoride-releasing composite resin of TC. 5. The highest value of fluoride release after toothbrushing by Perio Alpine Herb was $2.064{\mu}g/cm^2$ in CF group and the lowest value was $0.1119{\mu}g/cm^2$ in TC group. The amount of fluoride release of CF group was significantly higher than other groups (P<0.05).

  • PDF

Developmental Genetic Analysis of Avian Primordial Germ Cells and the Application to Poultry Biotechnology

  • Kagami, H.
    • Korean Journal of Poultry Science
    • /
    • v.28 no.2
    • /
    • pp.135-142
    • /
    • 2001
  • A novel sterategy has been established to determine the origin of the Primordial Germ Cells (PGCs) in avian embryos directly and the developmental fate of the PGCs for the application to Poultry biotechnology. Cells were removed from 1) the centre of area pellucida, 2) the outer of area pellucida and 3) the area opaca of the stage X blastoderm (Eyal-Giladi & Kochav, 1976). When the cells were removed from the centre of area pellucida, the mean number of circulating PGCs in blood was significantly decreased in the embryo at stage 15 (Hamburger & Hamilton, 1951) as compared to intact embryos. When the cells were replenished with donor cells, no reduction in the PGCs number was observed. The removal of cells at the outer of area pellucida or at the area opaca had no effect on the number of PGCs. In case, another set of the manipulated embryos were cultured ex vivo to the hatching and reared to the sexual maturity, the absence of germ cells and degeneration of seminiferous tubules was observed in resulting chickens derived from the blastoderm in which the cells were removed from the centre of the area pellucida. It was concluded that the avian Primordial Germ cells are originated at the center of area pellucida. Developmental ability of the cells to differentiate into somatic cells and germ cells in chimeras were analyzed. Somatic chimerism was detected as black feather attributed from donor cells. Molecular identification by use of female - specific DNA was performed. It was confirmed that the donor cells could be differentiated into chimeric body and erythrocytes. Donor cells retained the ability to differentiate into germline in chimeric gonads. More than 70% of the generated chimeras transmitted donor derived gametes to their offspring indicating that the cells at the center of area pellucida had the high ability to differentiate into germ cells. A molecular technique to identify germline chimerism has been developed by use of gene scan analysis. Strain specific DNA fragments were amplified by the method. It would be greatly contributed for the detection of germline chimerism. Mixed- sex chimeras which contained both male and female cells were produced to investigate the developmental fate of male and female cells in ovary and testes. The sex combinations of donor and recipient of the resulting chimeras were following 4 pairs; (1) chimeras (ZZ/ZZ) produced by a male donor (ZZ) and a male recipient (ZZ), (2) chimeras (ZW/ZW) produced by a female donor (ZW) and a female recipient (ZW), (3) chimeras (ZZ/ZW) Produce by a male donor (ZZ) and a female recipient (ZW), (4) chimeras (ZW/ZZ) produced by a female donor (ZW) and a male recipient (ZZ). It was found that genetically male avian germ cells could differentiate into functional ova and that genetically female germ cells can differentiate into functional spermatozoa in the gonad of the mixed- sex chimeras. An ability for introduction of exogenous DNA into the PGCs from stage X blastoderms were analyzed. Two reporter genes, SV-$\beta$gal and RSV-GFP, were introduced into the PGCs. Expression of bacterial/gal was improved by complexing DNA with liposome detectedcc in 75% of embryos at 3 days embryos. At the embryos incubated for 1 day, expression of the GFP was observed all the embryos. At day 3 of incubation, GFP was detected in about 70% of the manipulated embryos. In case of GFP, expression of the transgene was detected in 30 %e of the manipulated embryos. These results suggested that the cells is one of the most promising vectors for transgenesis. The established strategy should be very powerfull for application to poultry biotechnology.

  • PDF

Flow Resistance and Modeling Rule of Fishing Nets 5. Total Resistance of Bottom Trawl Nets Subjected Simultaneously to the Water Flow and the Bottom Friction (그물어구의 유수저항과 모형수칙 5. 저층 트롤그물의 예망저항)

  • KIM Dae-An
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.30 no.5
    • /
    • pp.700-707
    • /
    • 1997
  • In order to express exactly the total resistance of bottom trawl nets subjected simultaneously to the water flow and the bottom friction, the influence of frictional force was added to the formular for the flow resistance of trawl nets obtained by previous papev and the experimental data obtained by other investigators were analyzed by the formula. The analyzation produced the total resistance R (kg) expressed as $$R=4.5(\frac{S_n}{S_m})^{1.2}S\;v^{-1.8}+20(Bv)^{1.1}$$ where $S(m^2)$ was the wall area of nets, $S_m\;(m^2)$ the cross-sectional area of net mouths, $S_n\;(m^2)$ the area of nets projected to the plane perpendicular to the water flow, B (m) the made-up circumference at the fore edge of bag parts, and v(m/sec) the dragging velocity. From the viewpoint that expressing R in the form of $R=kSv^2$ was a usual practice, however, the resistant coefficient $k(kg{\cdot}sec^2/m^4)$ was compared with the factors influencing it by reusing the experimental data. The comparison gave that the coefficient k might be expressed approximately as a function of BL only and so the resistance R (kg) as $$R=18{\alpha}B^{0.5}L\;v^{1.5}$$ where L (m) was the made-up total length of nets and $\alpha=S/BL$. But the values of a in the nets did not deviate largely from their mean, 0.48, for all the nets and so the general expression of R (kg) for all the bottom trawl nets could be written as $$R=9\;B^{0.5}\;L\;v^{1.5}$$.

  • PDF