• 제목/요약/키워드: half-dose

Search Result 536, Processing Time 0.022 seconds

Control of heparinization by activated clotting time during extracorporeal circulation (개심술시 Activated Clotting Time 을 이용한 Heparin 투여 조절에 관한 임상적 고찰)

  • 서충헌
    • Journal of Chest Surgery
    • /
    • v.16 no.3
    • /
    • pp.281-288
    • /
    • 1983
  • Heparinization is an essential step in extracorporeal circulation for open heart surgery. But wide individual variation to heparin effect sometimes makes it difficult to anticoagulate safely or neutralize appropriately. Because the conventional set protocol of heparinization did not consider this individual variation, a new method of control of heparinization was proposed by Dr. Brian Bull in 1974. We compared the group in which a conventional set protocol was used [Control group] with the other in which a new protocol modified from that of Bull was used [ACT group], on the aspects of the dosages of heparin and protamine administered and postoperative bleeding. Our conventional protocol [Control group] consisted of: 1. Initial heparin was given at dose of 350U/Kg into the right atrium prior to bypass. 2. Additional heparin was given every hour during E.C.C., as much as a half of the Initial dose. 3. 600U of heparin was mixed into every 100ml. of priming solution. 4. The protamine dose was calculated by totalling the units of heparin given to the patient and giving 1 .8mg. of protamine per 100 units of heparin. ACT protocol [ACT group] consisted of: 1. Initial heparinization was same as that of conventional protocol. 2. ACT`s were checked before [A point] and 10 minutes after initial heparinization [B point]. With these 2 points, a dose response curve was drawn. 3. Heparin for the priming solution was same as in control group. 4. Every 30 minutes during E.C.C., ACT`s were checked with Hemochron [International Technidyne Corp.]. ACT between 450 and 600 seconds was regarded as safety zone. If ACT checked at a time was below 450 seconds, heparin dose was calculated on the dose-response curve to lengthen ACT to 480 seconds and was given into the oxygenator. 5. About 10 minutes before the term of E.C.C., ACT was checked to estimate the blood heparin level at the time. Then, protamine dose was calculated at dose of 1.Stag per 100 units of heparin. The calculated dose of protamine was mixed into 50 to lO0ml of 5% Dextrose Water and dripped intravenously during the period of 15 minutes. Compared these two groups mentioned above, results were obtained as follows: 1. Mean value of normal ACT checked with Hemochron on 30 preoperative patients was 124 seconds [range 95-145 sec.]. 2. Doses of heparin and protamine given to the patient were decreased in ACT group as much as 32.2% and 62.2% respectively. 3. Postoperative bleeding and transfusion were also decreased in ACT group in 60.5% and 67.1% respectively. 4. Our modified dose-response curve did not cause any problems in the control of heparinization. 5. Initial heparinization [Heparin 350U/Kg] was sufficient for the most patients until 60 minutes under extracorporeal circulation. 6. We used 1.5mg of protamine to neutralize 100 units of heparin. But smaller dose of protamine may be sufficient for appropriate neutralization.

  • PDF

Study on the Measurement of $^{51}Cr-tagged$ Red Cell Survival - Reevaluation of its method & the effect of Blood loss on red cell suruival with $^{51}Cr$ - (방사성동위원소(放射性同位元素) $^{51}Cr$을 이용(利用)한 적혈구수명(赤血球壽命) 측정(測定)에 관(關)한 고찰(考察) -$^{51}Cr$-적혈구수명(赤血球壽命) 측정법(測定法)의 재평가(再評價)와 실혈(失血)이 수명측정(壽命測定)에 미치는 영향(影響)에 관(關)한 연구(硏究))

  • Choi, Hak-Yong;Koh, Chang-Soon;Lee, Moon-Ho
    • The Korean Journal of Nuclear Medicine
    • /
    • v.4 no.2
    • /
    • pp.55-66
    • /
    • 1970
  • Reappraisal measurements of apparent half survival time of red cell by $^{51}Cr$ method was made and effects of blood-letting over red cell survival were observed. The study was performed on 53 normal male subjects under three different experimental conditions. 1. Group 1 Mean $^{51}Cr$ red cell half survival by ACD wash method was 29.7 days. $T\frac{1}{2}$ of Ascorbic acid method was 29.0 days in group with 100 mg dose and 29.1 days in group with 50 mg dose respectively. There was no difference between these two methods in regards to red cell half survival. No difference were noted in amount of ascorbic acid administered. 2. Group 2 As daily amount of blood loss is increased the shortening of red cell half survival was noted. Rapid phase was seen when blood loss ranged 10 to 25 ml per day, while slow phase noted when more loss amounted 25 ml or more daily. Thus, it was clear that there was more than an exponential relation between $T\frac{1}{2}$ and the amount of blood loss. 3. Group 3 $T\frac{1}{2}$ measured by cpm per whole blood was within normal range and $T\frac{1}{2}$ measured by cpm per red cell mass showed shortening tendency when compared with the former in the group measured after blood loss (from 25 ml daily up to 100 ml daily in 10 days). In the group with rather constant blood loss of 100 ml daily for 10 consecutive days revealed the significant difference in two measurements (P<0.01). 4. $T\frac{1}{2}$ in non-steady state When red cell production is increased compared with red cell destruction, $T\frac{1}{2}$ measured by cpm per red cell mass being shorter than that by cpm per whole blood. Shortening of $T\frac{1}{2}$ measured by cpm per whole blood is more prominent. if red cell destrction is enhanced and exceeds production. 5. It is clear that when expressing red cell destruction rate, $T\frac{1}{2}$ measured by cpm per whole blood is more adequate and production more consistent with cpm red cell mass. 6. $T\frac{1}{2}$ measured during blood-letting, when corrected by amount of blood loss, it remains normal. It is erroneous to use conventional equational when measuring $T\frac{1}{2}$ in non-steady. $T\frac{1}{2}$ measured by cpm per whole blood is considred more applicable in clinical evaluation.

  • PDF

On the preparation of new formulation of Diazinon and its residual pattern in submerged soil (새로운 Diazinon입제의 제조 및 담수토양중의 잔류특성에 관하여)

  • Choi, Jong-Woo;Ryoo, Jong-Gook;Shin, Dong-Lin;Lee, Kyu-Seung
    • Korean Journal of Environmental Agriculture
    • /
    • v.11 no.1
    • /
    • pp.1-8
    • /
    • 1992
  • New formulation of diazinon as granule preparing with piperonyl butoxide(PBO) and triphenyl phosphate(TPP) known as the inhibitor of monooxygenase(mo) and esterase was tested with the mortality of rice leaf hopper. Also, the mixed formulation of diazinon with tricyclazole, carbofuran and EPN were investigated about the residual pattern of diazinon in submerged soil condition at $30{\pm}2^{\circ}C$. Although the mortality about rice leaf hopper was higher only 10% on new formulation of diazinon than commercial at recommended dose but was 30-60% at half dose. Half life of diazinon in the formulation with 0.1% of PBO+TPP was 4.53 days in sterilized soil and 2.33 days in non-sterilized soil, and it was delayed about 0.74 and 0.45 respectively in contrast with the commercial granule. Also, half life of the new formulation with 1% PBO and PBO+TPP was delayed 0.44(PBO) and 0.65day(PBO+TPP) in non-sterilized soil condition, respectively. Half life of mixed formulation with tricyclazole, carbofuran, EPN or EPN+Carbofuran was delayed 2.61, 1.04, 0.43 or 2.7 days, respectively. As a result, the persistence rate of new formulation and mixed formulation was increased by inhibition of two enzymes affecting to the dgradation of diazinon in submerged soil.

  • PDF

The Daily Dose and Decoct Method of Rhubarb in Treatise on Cold Damage Diseases (상한론 탕제(傷寒論 湯劑)에서 대황(大黃) 1일 복용량과 추출법)

  • Kim, In-Rak
    • The Korea Journal of Herbology
    • /
    • v.31 no.3
    • /
    • pp.37-41
    • /
    • 2016
  • Objectives : The purpose of this study is to assume the size of sliced piece, daily dose and extracting Method of Rhubarb in Treatise on Cold Damage Diseases.Methods : I contrast results of recent studies with assuming results based on original text of Treatise on Cold Damage Diseases.Results : Daily dose was 6, 4 or 2 Ryang in case of cutting Rhubarb in bean-size. These prescriptions were decocted with water or sinked in boiled water. Another daily doses were large baduk-piece size 6 units and baduk-piece size 6 units in case of cutting Rhubarb in size bigger than bean. The former was used in adding to the Jisilchijasi-tang in case of constipation, the latter was used in Sihogayonggolmoryeo-tang and Jeodang-tang. The size of large baduk-piece was 2.32 cm in width, 4.64 cm in length, 4.3 g in weight, and the length and weight of baduk-piece was half of that was. Two sizes of Rhubarbs were sunk in water for 12 hours. After decocting the other ingredients, mixed Rhubarb extraction and Rhubarb, and then boiled it for 1 minute.Conclusions : From this study, daily dose of Rhubarb was 6, 4 or 2 Ryang and the 6 pieces of large baduk-piece or baduk-piece are respectively 4 or 2 Ryang. The extracting methods was decocting, sinking in boiled water for short time, sinking in water for long time and then mixing these with other decocted solution.

Effects of electron beam irradiation on the superconducting properties of YBCO thin films

  • Lee, Y.J.;Choi, J.H.;Jun, B.H.;Joo, J.;Kim, C.S.;Kim, C.J.
    • Progress in Superconductivity and Cryogenics
    • /
    • v.18 no.4
    • /
    • pp.15-20
    • /
    • 2016
  • The effects of electron beam (EB) irradiation on the superconducting critical temperature ($T_c$) and critical current density ($J_c$) of YBCO films were studied. The YBCO thin films were irradiated using a KAERI EB accelerator with an energy of 0.2 MeV and a dose of $10^{15}-10^{16}e/cm^2$. A small $T_c$ decrease and a broad superconducting transition were observed as the EB dose increased. The value of $J_cs$ (at 20 K, 50 K and 70 K) increased at doses of $7.5{\times}10^{15}$ and $2.2{\times}10^{16}e/cm^2$. However, $J_cs$ decreased as the dose increased further. The X-ray diffraction (XRD) analysis showed that the c axis of YBCO was elongated and the full width at half maximum (FWHM) increased as the dose increased, which is strong evidence of the atomic displacement by EB irradiation. The transmission electron microscopy (TEM) showed that the amorphous layer formed in the vicinity of the surfaces of the irradiated films. The amorphous phase was often present as an isolated form in the interior of the films. In addition to the formation of the amorphous phase, many striations running along the a-b direction of YBCO were observed. The high magnification lattice image showed that the striations were stacking faults. The enhancement of $J_c$ by EB irradiation is likely to be due to the lattice distortion and the formation of defects such as vacancies and stacking faults. The decrease in $J_c$ at a high EB dose is attributed to the extension of the amorphous region of a non-superconducting phase.

Evaluation of Dosimetric Effect and Treatment Time by Plan Parameters for Endobronchial Brachytherapy

  • Choi, Chang Heon;Park, Jong Min;Park, So-Yeon;Kang, SungHee;Cho, Jin Dong;Kim, Jung-in
    • Progress in Medical Physics
    • /
    • v.28 no.2
    • /
    • pp.39-44
    • /
    • 2017
  • This study aims to analyze dose distribution and treatment time of endobronchial brachytherapy (EBBT) by changing the position step size of the dwell position. A solid water phantom and an intraluminal catheter were used in the treatment plan. The treatment plans were generated for 3, 5, 7, and 10 cm treatment lengths, respectively. For each treatment length, the source position step sizes were set as 2.5, 5, and 10 mm. Three reference points were set 1 cm away from the central axis of the catheter, along the axis, for uniform dose distribution. Volumetric dose distribution was calculated to evaluate the dosimetric effect. The total radiation delivery time and total dwell time were estimated for treatment efficiency, which were increased with position step sizes. At half-life time, the differences between the position step sizes in the total radiation delivery time were 18.1, 15.4, 18.0, and 24.0 s for 3, 5, 7, and 10 cm treatment lengths, respectively. The dose distributions were more homogenous by increasing the position step sizes. The dose difference of the reference point was less than 10%. In brachytherapy, this difference can be negligible. For EBBT, the treatment time is the key factor while considering the patient status. To reduce the total treatment time, EBBT can be performed with 2.5 mm position step size.

Single Oral Dose Toxicity Studies of Polycan, β-Glucan Originated from Aureobasidium in Mice

  • Lee, Hyeung-Sik;Yang, Kun-Ju;Shin, Hyun-Dong;Park, Bok-Ryeon;Son, Chang-Woo;Jang, Hee-Jeong;Park, Dong-Chan;Jung, Young-Mi;Ku, Sae-Kwang
    • Toxicological Research
    • /
    • v.21 no.4
    • /
    • pp.361-365
    • /
    • 2005
  • This study was conducted to obtain the acute information of the oral dose toxicity of Polycan - originated from Aureobasidium pullulans SM-2001 (half of the dry material is -1,3/1,6-glucans), a UV induced mutant of A. pullulans, having various pharmacological effects, in male and female mice. In order to calculate $50\%$ lethal dose $(LD_{50})$, approximate LD and target organs, test article was administered twice by oral gavage to male and female ICR mice at total 1000, 500 and 250mg/kg. The mortality and changes on body weight, clinical signs and gross observation were monitored during 14 days after dosing. As the results, we could not find any mortalities, clinical signs, changes in the body weight and gross findings. The results obtained in this study suggest that the Polycan is non-toxic in mice and is therefore likely to be safe for clinical use. The L050 and approximate $(LD_{50})$ in mice after single oral dose of Polycan were considered over 1000 mg/kg, respectively.

Determination of Initial Beam Parameters of Varian 2100 CD Linac for Various Therapeutic Electrons Using PRIMO

  • Maskani, Reza;Tahmasebibirgani, Mohammad Javad;Hoseini-Ghahfarokhi, Mojtaba;Fatahiasl, Jafar
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.17
    • /
    • pp.7795-7801
    • /
    • 2015
  • The aim of the present research was to establish primary characteristics of electron beams for a Varian 2100C/D linear accelerator with recently developed PRIMO Monte Carlo software and to verify relations between electron energy and dose distribution. To maintain conformity of simulated and measured dose curves within 1%/1mm, mean energy, Full Width at Half Maximum (FWHM) of energy and focal spot FWHM of initial beam were changed iteratively. Mean and most probable energies were extracted from validated phase spaces and compared with related empirical equation results. To explain the importance of correct estimation of primary energy on a clinical case, computed tomography images of a thorax phantom were imported in PRIMO. Dose distributions and dose volume histogram (DVH) curves were compared between validated and artificial cases with overestimated energy. Initial mean energies were obtained of 6.68, 9.73, 13.2 and 16.4 MeV for 6, 9, 12 and 15 nominal energies, respectively. Energy FWHM reduced with increase in energy. Three mm focal spot FWHM for 9 MeV and 4 mm for other energies made proper matches of simulated and measured profiles. In addition, the maximum difference of calculated mean electrons energy at the phantom surface with empirical equation was 2.2 percent. Finally, clear differences in DVH curves of validated and artificial energy were observed as heterogeneity indexes were 0.15 for 7.21 MeV and 0.25 for 6.68 MeV. The Monte Carlo model presented in PRIMO for Varian 2100 CD was precisely validated. IAEA polynomial equations estimated mean energy more accurately than a known linear one. Small displacement of R50 changed DVH curves and homogeneity indexes. PRIMO is a user-friendly software which has suitable capabilities to calculate dose distribution in water phantoms or computerized tomographic volumes accurately.

Feasibility of clay-shielding material for low-energy photons (Gamma/X)

  • Tajudin, S.M.;Sabri, A.H.A.;Abdul Aziz, M.Z.;Olukotun, S.F.;Ojo, B.M.;Fasasi, M.K.
    • Nuclear Engineering and Technology
    • /
    • v.51 no.6
    • /
    • pp.1633-1637
    • /
    • 2019
  • While considering the photon attenuation coefficient (${\mu}$) and its related parameters for photons shielding, it is necessary to account for its transmitted and reflected photons energy spectra and dose contribution. Monte Carlo simulation was used to study the efficiency of clay ($1.99g\;cm^{-3}$) as a shielding material below 150 keV photon. Am-241 gamma source and an X-ray of 150 kVp were calculated. The calculated value of ${\mu}$ for Am-241 is higher within 5.61% compared to theoretical value for a single-energy photon. The calculated half-value layer (HVL) is 0.9335 cm, which is lower than that of ordinary concrete for X-ray of 150 kVp. A thickness of 2 cm clay was adequate to attenuate 90% and 85% of the incident photons from Am-241 and X-ray of 150 kVp, respectively. The same thickness of 2 cm could shield the gamma source dose rate of Am-241 (1 MBq) down to $0.0528{\mu}Sv/hr$. For X-ray of 150 kVp, photons below 60 keV were significantly decreased with 2 cm clay and a dose rate reduction by ~80%. The contribution of reflected photons and dose from the clay is negligible for both sources.

Effect of Stitching Range on Radiation Dose to Eyeball, Thyroid, Breast, Pelvis in Whole Spine Radiography with Standing Position (선 자세 척추 전장 방사선검사 시 스티칭 범위가 장기(수정체, 갑상샘, 유방, 골반부)의 선량에 미치는 영향)

  • Min-Ji, Hong;Han-Yong, Kim;Dong-Hwan, Kim;Young-Cheol, Joo
    • Journal of the Korean Society of Radiology
    • /
    • v.17 no.1
    • /
    • pp.47-52
    • /
    • 2023
  • In whole spine radiography using the stitching technique, overlapping parts occur in the process of synthesizing the three segmented images, so some anatomical structures may be repeatedly exposed, and it has been thought that the dose increases as the scan range increases. However, in the whole spine radiography using the stitching technique in this study, under the condition that the stitching range is taken in the same three splits, the overlapping area decreases as the stitching range increases, so in the case of breasts included in the overlapping range, the dose value decreased by almost half as the stitching range increased from 90 cm to 105 cm. During spinal full-length radiological examination using the stitching method, an appropriately long stitching range could be set to reduce the exposure dose of the breast.